Proceedings of China SAE Congress 2023: Selected Papers

To accelerate the testing of the function boundary of AEB control strategy on a longitudinal slope, this paper proposed an improved GA-based method for generating critical collision scenarios of AEB on the longitudinal slope. The range constraint of AEB scenario parameters, the longitudinal dynamic constraint of slope and the emergency braking demand constraint of longitudinal slope were analyzed. Furthermore, by examining the collision conditions of AEB when the front vehicle is in three states (parking or maintaining a constant speed, accelerating and decelerating), an objective function for AEB critical collision scenarios with a slope was designed based on the satisfaction criterion model. The reasonable range of each parameter was determined by assessing the degree of constraint between AEB scenario parameters. An iterative operator was then designed to satisfy the constraints of the scene parameters and eliminate invalid scenarios. The results demonstrate that, under identical conditions, the proposed method and the improved GA method with penalty term generated effective scenarios in an average time of 0.45 s and 0.91 s, respectively. This indicates that the proposed method has nearly doubled the generation efficiency. By analyzing the critical collision scenario areas at coverage ratio of 50%, 80% and 100%, it was observed that the scenario area density increased with higher coverage ratio. The critical collision scene domain of the leading vehicle exhibited a distinct boundary under different conditions, with the influence of various longitudinal slopes on the critical collision scenario domain being significant. When employing the AEB function with fixed and adaptive time-to-collision strategies, the AEB systems were activated. In some critical scenarios, the former system resulted in a collision while the latter system successfully avoided a collision. This effectively tests the functional boundary of the AEB control strategy.

This article introduces the application of human-machine collaborative driving in multi-car platooning based on the Amazon DeepRacer autonomous driving platform, which includes the use of AirTag recognition and lane recognition. In traditional autonomous driving, vehicle control is mostly managed by algorithms with little human intervention. In our research, we enable both algorithms and drivers to share control, with algorithms providing precision and drivers offering adaptability. We discuss the principles and implementation methods of AirTag recognition and how the location information obtained from AirTag recognition can be applied to multi-car platooning. Furthermore, we explore the relevant technologies of lane recognition, which is the core of our autonomous driving system. Finally, we propose some improvement measures for practical application to ensure the safety and reliability of human-machine collaborative driving in multi-car platooning. The results of this article shows that manual driving can handle special situations, such as changing lanes, avoiding complex obstacles, and so on. Autonomous driving is more suitable for regular road driving and emergency situations.

Applying post-processing techniques to extract lane instances from binary segmentation images is an important step in lane detection based on semantic segmentation. This paper proposes a lane instance extraction algorithm based on prior knowledge and distance penalty modules, improving the random sample consensus algorithm. The prior knowledge module uses existing lane prior knowledge to set filtering conditions in the algorithm iteration process, enhancing the robustness of instance extraction. The distance penalty module applies an evaluation penalty based on the distance of lane feature points, solving the deviation at the near end of the lane model caused by a sudden change in the number of feature points due to perspective transformation and improving the accuracy of instance extraction. The experimental results on a large amount of testing data from various traffic scenarios demonstrate that the proposed algorithm can be applied to multi-lane detection post-processing tasks containing any number of lanes, with an instance extraction accuracy rate of 98.53%. It has good instance extraction capabilities for lanes with any curvature, with an average extraction error as low as 16.85 pixels, and stable extraction performance for various types of lanes, such as solid and dashed lines.

Intelligent connected vehicle platooning technology utilizes vehicle-to-vehicle communication to enhance urban road efficiency and ensure driving safety. This paper focuses on the vehicle platoon motion planning algorithm, which constructs a reference path for platoon vehicles based on smoothed historical trajectory points of the lead vehicle. The algorithm generates path boundaries considering road and obstacle information, creates candidate paths using lateral and longitudinal sampling, and selects the optimal path using a cost function. A velocity planning algorithm is developed for platoon vehicles, incorporating dual-mode strategies for platoon cruise and obstacle avoidance based on different scenarios. A safety risk assessment is established, guiding the choice of speed planning mode. Real-world experiments validate the planning outcomes, evaluating speed, acceleration, and inter-vehicle distance. Results indicate well-smoothed trajectories with good comfort and safety attributes.

Efficient and accurate real-time detection of semi-structured driving boundaries within the park is required by unmanned ground vehicles (UGVs) in order to facilitate vehicle positioning and path planning. These boundaries have a regular shape, but do not have obvious line and surface features, such as low shrubs. It is crucial for ensuring optimal navigation for UGVs. We have developed a new method for detecting semi-structured boundaries based on 3-dimensional Light Detection and Ranging (3D LiDAR), which involves three key steps. The first step involved pre-processing the 3D raw laser point cloud, which included three tasks: coordinate correction, segmenting the region of interest (ROI), and ground point cloud segmentation to achieve point cloud down-sampling. Next, the non-ground points in ROI were projected onto the ground, and boundary feature points that affect the driving of UGV were extracted. To eliminate incorrect boundary points, a two-step method consisting of the Random Sample Consensus (RANSAC) algorithm and inter-frame boundary line angle elimination was used. In the third step, the data of Position and Orientation System (POS) were integrated to construct a global point cloud map of the semi-structured driving boundary. An experiment was conducted on a self-developed UGV-LiDAR platform to evaluate the performance of the proposed algorithm. It was indicated by the results of the study that the feature point detection rate was exceeded by 98.95%, and the average processing time per frame was around 45.7 ms when there are more shrubs, meeting the real-time demands. This research provided valuable insights into perception technology for security operations of UGVs in parks.

Fisheye cameras are widely employed in automatic parking, and the video stream object detection (VSOD) of the fisheye camera is a fundamental perception function to ensure the safe operation of vehicles. In past research, the difference between the output of the deep learning model and the actual situation at the current moment due to the existence of delay of the perception system is generally ignored. Nevertheless, the environment will inevitably change within the delay, which may cause a potential safety hazard. This paper proposes a real-time detection framework with a dual-flow perception module (dynamic and static flows) that can predict the future and alleviate the time-lag problem. Meanwhile, we use a new scheme to evaluate latency and accuracy. The standard bbox is unsuitable for the object in fisheye camera images due to the solid radial distortion of the fisheye camera. The primary detection objects of parking perception are vehicles and pedestrians, so we adopt the rotated bbox and propose a new periodic angle loss function to regress the angle of the box, which is the simple and accurate representation method of objects. The instance segmentation ground truth is used to supervise the training. Experiments demonstrate the effectiveness of our approach. Code is released at: https://gitee.com/hiyanyx/fisheye-streaming-perception .

In order to test the safety of self-driving tractor-trailer vehicles when encountering snow and ice on low-grade roads, a convex corridor-based spatial path planning method adapted to snow and ice conditions is utilized. The method constructs a secure convex corridor in ice and snow regions by mapping obstacles and initial risks onto the Frenét coordinate system. It abstracts information such as safety, boundaries, and lateral control constraints, using the vehicle’s current position as the starting point. Spatial path optimization is then employed to generate a suitable and continuous speed trajectory. In light of the unique features of the ice and snow environment, a practical vehicle test was conducted on the Heihe test track. This test included four typical scenarios for automatic driving path planning on ice and snow road surfaces: cone bucket obstacle avoidance, pedestrian crossing, pedestrian following, and manhole cover. The experimental data collected during the test were processed in the tractor-trailer autopilot system. The results demonstrate that the method can effectively solve the quadratic planning problem with high robustness and practicality. This provides a valuable reference for the application of path planning algorithms in automatic driving technology, particularly in snow and ice areas.

Most researches concerning the yaw stability and rollover prevention for autonomous vehicles are studied separately and decoupled the longitudinal and lateral vehicle dynamics control. However, the roll motion influences the yaw stability during high speed curve steering manoeuvres. With this in mind, a curve trajectory stable tracking controller for autonomous vehicles using linear time-varying model predictive control (LTV MPC) is proposed in this paper. The lateral dynamics control employs the LTV MPC to generate a sequence of optimal steering angles considering the constraints of control input, state output, yaw stability and roll stability together in the cost function, in which the prediction model utilizes an 8 degrees of freedom (DOF) vehicle model and the plant utilizes a 14-DOF vehicle model. The longitudinal control adopts PID control embedded in the MPC framework to update the speed at each optimization step and generate the total wheel torque for speed tracking. The trajectory tracking simulation results demonstrate that the vehicle tracks the reference trajectory and speed well with the proposed controller, which satisfies the constraints of control input, state output as well as the boundaries of yaw stability envelope, sideslip angle and roll angle, thereby reducing the risk of vehicle skid and rollover.

VMT visual localization is a technology that employs cameras for non-contact positioning of workpieces. It is commonly used in high-precision automated sealing workstations for body positioning. The traditional approach to calibrating visual systems has been through online debugging. This method requires using production downtime, has short debugging time windows, long cycles, and incurs high trial-and-error costs. Moreover, the necessary coordinate transformation techniques in visual debugging are often proprietary and require expensive outsourcing due to foreign vendor confidentiality. To address these challenges, this paper proposes two optimizations for visual calibration methods: 1.a novel offline debugging approach to replace the conventional online debugging, reducing the debugging cycle and enhancing efficiency. 2. an innovative coordinate transformation strategy and implementation method, along with a one-click transformation feature implemented through Python code. Lastly, the effectiveness of the proposed methods is demonstrated through application on new vehicle models. This leads to significant cost savings in debugging expenses. The approach has been successfully promoted within the company.

The continuous updated environmental protection laws on the exhaust gas treatment of the automobile industry has put forward specific guidance and stricter emission requirements. Automobile company follows environmental protection laws requirement, the treatment of the exhaust is from solvent borne paint to water borne paint. Deep treatment needs to consume a lot of electric and natural gas for spray booth’s exhaust have large volume and low concentration. To explore the energy saving treatment of the exhaust and realize the efficient operation of the spray booth and exhaust treatment system can help the automobile industry achieve carbon dioxide emissions peak and carbon neutrality.

This paper investigates a special roof panel as the research object and conducts a simulation analysis to study issues such as crack and wrinkle, and quality defects of A-class surface during the forming process. Integrating the requirements of die structure, welding, and sealing, the paper proposes feasible optimization schemes for the product structure and stamping process. After through trial production and validation, the parts meet the quality standards, achieving a perfect combination of product design and manufacturing process.

In the process of multi-vehicle door collinear flexible production in the automobile companies, the handing tools are dedicated to ATC (automatic tool changer) and have complex structure, large area and complex line body. Taking the four-door flexible collinear production of Dongfeng Honda Automobile Co., LTD as an example, combined with the product design characteristics, MTP (Manufacturing and Technical Proposal) system was integrated and set by D&E (Designer & Engineering) to confirm the connection handing jig and sheet metal design features, and finally designed the four-door collinear flexible universal handing jig and sheet metal features of door products. The results show that the setting and application of universal MTP can effectively simplify the handing jig structure, eliminate the handing jig, reduce the occupied site, reduce the cost and the time of subsequent new model synchronous engineering and equipment debugging, especially for the early cost reduction of new plant construction.

The national standard GB26512-2021 of “The protection of the occupants of the cab of commercial vehicles” brings challenges to automobile enterprises to meet certification requirements. This paper introduces the technical route of revisions of GB26512-2021, and analyzes the technical requirements of GB26512-2021 for automobile test institutions and commercial vehicle manufactures. This paper introduces the technical route of revisions of GB26512-2021, and analyzes common key issues of test method of this standard in the course of implementation. This paper introduces the technical route of revisions of GB26512-2021, and analyzes common key issues of test method of this standard in the course of implementation. Based on the basis of a large number of test dates and typical test cases with the domestic manufactures, the paper introduces the solution that the cab of commercial vehicles adopts high strength frame structure, then conducts a research and analysis on the specific structure of the typical test problem cases, then analyzes the common key issues of test method of this standard in the course of implementation. Typical test problem cases, then analyzes the methods that the manufacturers improve key collision components at a lower cost. This paper provides some This paper provides some reference suggestions for solutions on safety standard of structural strength of commercial vehicle cab in china, and development test of commercial vehicle cab.

This paper analyzes the deviation of concentricity measured by coordinate measuring machine (hereinafter referred to as CMM). We can select a better measurement system and sampling strategy, so as to improve the accuracy of concentricity measured by CMM to the greatest extent. It is the first time to put forward the concept of uncertainty in measuring concentricity with different CMM under specific conditions. This paper analyzes the advantages and disadvantages of various flexible measurement methods, also point out the calculation defects of common axis method and straightness method and the possibility of misjudgment. Finally, the author summarizes the experience of measuring concentricity with CMM.

Part deviation mean, the matching two parts, the mean deviation direction should be consistent, and the deviation is consistent; For mass-produced parts, there are fluctuations between individual and individual parts, The deviation mean trend is consistent (P’ small), It does not mean that the P value of the vehicle DTS target can be achieved. By matching the sample frame, from focusing on the qualified rate of single parts to the matching of associated parts, And to evaluate the matching of the door cover size tolerance, Improve the matching ability of overlays, Combined with the encrypted measurement data application, lock the problem points; Using optical scanning, the deviation value is evaluated by locating the fitting with the contour matching point. Through the fitting evaluation of the outer plate, the problems are intuitively found and rectified.

Maintainability, as one of the evaluation factors of automobile quality, will affect the purchase decision of users to a certain extent, which makes it more widely valued in product research and development. This paper puts forward the dimension, method and comprehensive evaluation model of automobile maintainability analysis from the perspective of technology, and evaluates the maintainability in the engineering design phase, providing a quantitative evaluation basis for the maintainability of automobile design.

The phenomenon of abnormal seat belt load limit force under front collision conditions was studied. Based on the seat belt restraint system model and FTA, the shoulder force in each stage under front collision conditions was analyzed, with a focus on analyzing various possible factors of abnormal shoulder force during the force limiting stage and FTA model for abnormal shoulder force was established. Based on a specific practical case, analyze the impact of each factor in the FTA model on abnormal shoulder force and eventually form a force limiting correlation table for the root cause. A comprehensive analysis of the abnormal seat belt shoulder force from the constraint system level is summarized, which can quickly and comprehensively identify the root cause for the abnormal shoulder force and has a certain reference significance in the industry.

The fundamental significance of the Architecture of a vehicle platform was studied and practiced in this paper. Using Architecture to determine different kinds of modular platforms was an effective means, and also put forward new proposals for their optimization. Based on benchmarking and development experiences of passenger vehicle modular platforms, the concept and characteristics of a vehicle platform architecture was proposed in this paper. By analyzing the evolution process and development strategy of modular platforms for fuel engines, hybrid powertrains and battery electric vehicle platforms, the internal motivations for the construction of the platform was refined. The elements and methods of platform architecture design were summarized, such as primary parameters, modules, interfaces, principles etc. It has reference significance for the architecture development of brand-new platforms and vehicle models in the future.

The poor vibration absorption performance and large amplitude of seat during driving are common in vehicle development and market compliant. This paper establishes forced vibration and free vibration models of seat, and proposes a prediction method of seat vibration absorption performance. Then it analyses a ventilation seat by FTA method, and identifies factors that affect vibration absorption performance, such as seat weight, foam hardness, foam structure, ventilation bag hardness, suspension mat stiffness, whether suspension mat can deform freely or not, foam damping and so on. Finally, this paper proposes the countermeasures, and confirms that the above design method is effective by bench test and vehicle evaluation. This paper will provide reference for the design of seat vibration absorption performance.

The purpose of this paper is to study the platform performance optimization method based on implicit parametric body. Firstly, the body structure path is optimized based on topology optimization; Secondly, an approximate substitution model is constructed through machine learning to optimize the modal and stiffness performance. The collision performance is simultaneously optimized using black box optimization with modal and stiffness as the constraint condition; By overlaying and verifying the optimization scheme of modal and stiffness and collision, the final vehicle platform modal and stiffness performance can be improved by 5%–20%, and the SOB collision intrusion rate can be increased by about 50% or more, forming a vehicle platform performance optimization method. This method can effectively balance the relationship between modal, stiffness, collision and weight, and provide reference for the subsequent development of platform performance.

Steering column system main performance requirements are fully analyzed especially the structure performance, ergonomics performance etc. These dimensions are analyzed by deriving trends through simplifying algorithm, optimizing comfort range through statistical method, and puts forward concrete suggestions on quantitative target respectively. On this basis, torque fluctuation and ergonomics comfort issues in MPV under ESSA architecture are solved, and the modular development strategy of all four different types of vehicles under ESSA architecture is implemented, which ensures that the steering column system can not only meet the requirements of main performance, but also achieve the predetermined goal of maximum universality.

According to solve three different types of engine mount stopper noise or abnormal vibration problem, including assembly issue, Y direction stopper issue and X direction stopper issue, detailed description the analysis process, countermeasure and verification of noise or abnormal vibration due to stopper or stopper poor design, then summarize the analytical method and solution of engine mount stopper issue, the analytical method and solution in this paper can also as reference for the other abnormal noise in chassis.

Taking the permanent magnet synchronous motor used in electric vehicle drives as the research object, this paper analyzes the influence of harmonic components on the vibro-acoustic response. A speed/torque harmonic injection method has been constructed to suppress the electromagnetic noise. Based on a certain NVH test and its related results, the harmonic influence on the electromagnetic acoustic noise has been firstly analyzed. Secondly, a high-speed mathematical motor model and a radial electromagnetic force model, considering the magnetic interaction between the stator winding harmonics and the permanent magnet, are fully established. The correlation between harmonic components and radial electromagnetic force has been also analyzed considering the speed/torque factors. Then, a harmonic injection method based on SVPWM is further proposed, in which the control model for the 5th and 7th harmonic currents are also implemented. Finally, with the experimental verification under different speed and torque conditions, the results show that the harmonic injection method can effectively suppress electromagnetic noise. This work can provide the theoretical and practical basis for optimizing the electromagnetic noise in the drive motor system.

A SUV has the problem of body lateral vibration and steering wheel vibration during acceleration. By using the transfer path analysis, the axial derived force produced by the tripod constant velocity universal joint is the main excitation source. Then the fundamental cause of axial generation force is analyzed theoretically. It is concluded that the factors affecting the axial force include driving torque, included angle of transmission shaft, grease lubrication coefficient and ball joint form. And four improvement schemes are given. The research results show that, by reducing the included angle of the transmission shaft, the body lateral vibration is improve effectively and the measured vibration at the seat rail is reduced by 10dB.

Tire cavity resonance noise is vehicle interior noise caused by tire cavity resonance, which can be clearly felt by passengers inside the vehicle when driving at high speeds on flat road or at low speeds over bumps. This article analyzes the mechanism of the tire cavity resonance noise and proposes control strategies for tires, wheels, and suspension systems. Based on the problem of excessive tire cavity resonance noise in a certain vehicle, a problem analysis was conducted based on the control strategy proposed in this article. The identified reason was the coupling resonance between the rear suspension mode and the tire cavity mode, which caused the vibration generated by the tire cavity resonance to be amplified during the transfer to the vehicle body. The tire cavity resonance noise was reduced significantly by installing a dynamic damper on the rear suspension of the vehicle.

Torsional vibration of the vehicle driveline system interacts with the pitch motion of the powertrain. This paper presents the establishments of a coupled vibration model of mounting and driveline system. The coupled model is utilized to analyze a transient issue that oscillation occurs to both the mounting and driveline of a vehicle during the rapid disengagement of the clutch. In comparison to independent models, the modal frequency calculated by coupled model is more consistent with the experimental result. The coupled model also demonstrates high accuracy in time domain analysis. The paper conducts parameters sensitivity analysis, and it is confirmed that the torsional damping of the half shaft is the primary parameter responsible for attenuating system oscillation. The coupled model can be extended to analyze low-frequency coupled vibration of mounting and driveline in other situations.

In this paper, the torsional vibration characteristics of series spring torsional damper for hybrid electric vehicle are studied. Firstly, dynamic sofeware is used to build the physical simulation model of the hybrid transmission system under the direct drive acceleration condition, and the modal analysis of the transmission system is carried out, and the local mode of the series spring torsional damper is found. Through the torsional vibration analysis and real vehicle test of the hybrid power train, the influence of the local mode of the series spring torsional damper on the torsional vibration of the power train is confirmed, local modes can amplify the torsional vibration response of the drive train and cause the gear rattle problem. Secondly, the sensitivity analysis is carried out to find out the key influencing factors. Finally, the improved torsional damper is simulated to confirm the improvement effect. The conclusion provides a reference for the optimization of the series spring torsional damper.

For the transient response problem of an automobile bumper generated by pulse knocking conditions, subjective evaluation, response signal testing and statistical analysis are conducted to obtain the evaluation threshold of the shock response characteristics of the bumper. A finite element model of the bumper system is established and its accuracy is verified by modal testing. The multi-body dynamics model of bumper is established, and the response characteristics under different shock waveforms and different pulse durations are analyzed by simulating the pulse knocking conditions. The effects of the standard deviation of the load excitation, boundary frequency and energy index on the quality of the frequency response function are analyzed, and a composite pulse waveform with a predominantly initial-peak sawtooth waveform under hand knocking conditions is obtained by virtual load iterative waveform fitting method, which improves the accuracy of the simulation and provides a new guiding direction for the evaluation of the subjective and objective dynamic response characteristics and structural design of the automotive bumper.

A systematic analysis about the mechanism of flow induced low-frequency noise of new engine vehicle is presented. Firstly through the “opening-window” method in aero acoustic wind tunnel testing, the contribution and noise spectrum difference is analysed and compared about vehicle upper body and lower body. The test shows that low-frequency noise nearly totally generated by chassis parts because of the interaction between air flow and chassis, especially the tyre house contributes more. The SPL value of the chassis contribution is 9.8 dB(A) at driver seat and 13.8 dB(A) at rear seat and the main noise spectrum difference is below 500 Hz. Furthermore, deeply research about noise source in tyre house and the noise transfer path is performed. At last, an optimized method is carried out at the testing vehicle with enhancing sound absorption ability in tyre house and thickening the side glass. The maximum noise reduction achievement is 3.76 dB(A) at frequency domain.

This paper aims to study an optimization design for reducing the vertical transmission force of ball-type constant velocity joint (CVJ), in order to improve vehicle idle vibration. Firstly the vertical transmission force of ball-type CVJ is measured by bench equipment so the correlation between vertical transmission force amplitude and excitation amplitude, loaded torque, shaft length is obtained. Vertical transmission force amplitude of ball-type CVJ has a positive correlation with excitation amplitude and loaded torque, while negative with shaft length. Then vertical transmission force resultant in wheel sides in idle condition is calculated and a vehicle experiment is proceeded to measure cabin floor vertical vibration acceleration in the same condition. Moreover, an example is given to validate there is a strong linear correlation between the estimated values of vertical transmission force in wheel sides and the measured results of vehicle idle shake. Lastly major factors affecting vertical transmission force of ball-type CVJ are analyzed. Vertical transmission force can be restrained by using low friction grease, reducing ball-cage window interfere and enlarging ball pitch circle diameter (PCD) to optimize vehicle idle vibration. Control methods for vehicle idle vibration presented in this paper apply to both the oil-fueled and hybrid electric vehicles with engine.

In order to enhance the attitude control ability of all-terrain vehicles in complex terrain, a dual closed-loop control strategy based on LQR controller is designed with series active suspension all-terrain vehicles as the research object. Firstly, considering the kinematic and dynamic relationships between each mechanism of the all-terrain vehicle, a vehicle dynamic model based on the speed control of the actuator is constructed on the basis of the traditional active suspension force control. Secondly, a terrain estimation algorithm based on all-terrain vehicle model is studied, and a LQR controller suitable for attitude adjustment is designed. Finally, three pavement models are established to simulate real road conditions for verifying the accuracy of the dynamic model with terrain estimation model and the effectiveness of attitude control. The results show that the collaborative control strategy proposed in this paper has good adaptability to working conditions, and the peak and Root mean square values of vertical displacement, pitch angle and roll angle of all-terrain vehicle body are reduced by 30–50%, which can greatly improve the ride comfort and attitude stability of all-terrain vehicle.

Combining the movement characteristics of sliding door, the geometric model of sliding door motion is established, and the geometric model is decomposed to the XZ and YZ plane. Then, the formula is established to quantitatively analyze the change of rotation angle in the two planes when the sliding door opening and closing, and the main influencing factors of the rotation angle are obtained. At the same time, the smoothness evaluation model and method based on the change of rotation angle are provided. Finally, through DMU model and production vehicle verification, the results show that the calculated values of the evaluation model are highly consistent with the verification results. This study can quickly research and optimize the smoothness of sliding door in the early stage of development, saving the development cycle.

As the automobile market constantly matures and users’ automobile literacy improves, safety performance of cars has been increasingly garnering people’s attention. As safety performance is inextricably linked to the safety of occupants, it is the most noteworthy feature in car sales and ultimately affects the sales of cars. Collision accident can be classified into several types, including head-on collision, side collision, rear-end collision and roll-over collision and so on. Relevant data show that head-on collision is the most common type of collision, while in the fatal accidents of head-on collision, 25% small overlap barrier (SOB) accounts for about 1/4. This paper focuses on the real vehicle test and structural optimal design, in order to improve the safety performance of vehicles. China Insurance Automobile Safety Index, C-IASI is the first crash test guided by China Industry Insurance Association, and the test standards are in line with international first-class tests such as IIHS and E-NCAP. SOB is one of the key items of C-IASI. During SOB test, the vehicle hits the fixed rigid barrier at the speed of 64 km/h and 25% overlap rate. The safety performance is analysed according to the damage of the vehicle and the injury of the dummy in the vehicle.In the development process of this product, the Body in White (BIW) is faced with some problems, such as tight development time, high performance requirements, hard lightweight task and so on. Serious problems were exposed in the first round of SOB test. This paper studies the method of improving vehicle safety performance with small offset using finite element simulation technology and structure optimal designing. Through this research, the safety performance of small overlap collision of the vehicle can be significantly improved and the goal of lightweight can be achieved at the same time, indicating that this method has effective engineering application value.

Firstly, some hybrid powertrain system solutions of mainstream domestic and foreign car companies are introduced, and it is pointed out that a core reason for limited application of P2 parallel scheme in domestic car companies is that dual clutch assembly has always been in the hands of a few international component giants. Then a hybrid dedicated transmission scheme based on eTC is proposed, mainly consisting of an electric torque converter (eTC) and a dual input shaft gearbox. The eTC module includes a planetary mechanism, a motor, and two wet clutches, replacing the dual clutch module. Next, the modes of pure electric drive (EV), differential drive, hybrid drive (HEV), EV to HEV switching, engine & motor alternating drive and gear shifting that the system can achieve are analyzed. Finally, using MATLAB/SIMULINK software, a medium-sized bus is selected to conduct a simulation analysis of power and economy performance of the hybrid system. The results show that the hybrid vehicle has significantly improved power and economy performance compared to the basic one, with a fuel saving rate of over 24%, and has good market application prospects.

Based on dynamic programming in the frame of moving horizon control, an optimal control strategy for multi-speed electric vehicle shifting schedule considering the curvature of the road ahead is proposed. Based on the on-board visual perception capacity with map information, the obtained information of the lane line in front of the vehicle is obtained as the future trajectory. With the multi-point preview longitudinal driver model, the vehicle speed prediction is performed on multiple preview points on the future remote trajectory, acting as predicted information for following optimization. With the obtained predicted vehicle speed sequence, the dynamic programming method is used to perform optimal predictive control in the prediction domain, and the optimization objective function including the current driver’s dynamic intention, battery energy consumption, shift frequency and other factors is investigated. A simulation model is built to compare the proposed strategy with classic dual-parameter economy and dynamic shifting schedule. The results show that the optimal shift schedule strategy based on preview trajectory can save the power consumption of multi-gear electric vehicles, ensure the dynamic performance and reduce the shifting frequency.

An experimental optimization study was carried out to solve the problem of whine noise of a newlydeveloped commercial truck. Firstly, with the help of the vehicle road test, the minimum difference between the gear meshing one third octave order noise and narrowband order noise whether greater than 8 dB(A) can be as the judgment basis for the absence of whine in the cab. Secondly, with the help of sourcing-path-receiver analysis,transmission gear meshing excitation is mainly transmitted through the structural path; Finally, considering the feasibility and cost,by optimizing the accuracy of the 8th gears of the transmission and the structure of the connecting end of the shifting lock cab, the problem of whine noise in the cab of the truck was effectively solved.

In response to the problems of heavy commercial vehicles such as high steering axle load, high steering resistance, and high energy consumption, steering products pure electrification is an inevitable trend in technological development after the appearance of Electric Hydraulic Powered Steering (Further Called EHPS). This article introduces the structure and the compositions of the Commercial Vehicle Electrical Power Steering (Further Called CV-EPS) system briefly, simplifies and analyses the force on each component of the system, and elaborates on the mathematical models of each structure in detail. Based on the vehicle resistance model and the assist force characteristic curve, the transfer functions of the entire CV-EPS system are obtained. In the torque control section, an electric current loop PID controller is designed, and the PID parameters are effectively tuned based on the transfer functions. Regarding to the general problem of phase delay, a phase lead sector was designed for compensation. Finally, to analyse the stability of the system, a comprehensive simulation model of CV-EPS was built in the Simulink environment. The simulation results indicate that the CV-EPS system of heavy commercial vehicles has ideal dynamic performance and stability, and this method has great reference value and practical significance for improving the steering performance of the entire vehicle and optimizing the driver's steering feeling.

An AMT system composed of the clutch assembly with diaphragm spring and its pneumatic control actuator has typical nonlinear characteristics, which brings difficulties to high-precision automatic control. A nonlinear compensator has been designed based on the inverse function principle for this kind of nonlinear system, which has been verified by the simulation running on a clutch control simulink model and a simscape physical model of the clutch system. The clutch control rig test was also carried out. The results of simulation and rig test show that the control effect of the nonlinear compensator is better than that of the normal linear controller.

In order to cope with market changes, a certain commercial vehicle platform balance suspension system urgently needs to be lightweight to reduce costs. The suspension system is faced with a series of contact nonlinear problems of complex structures. The structure obtained by traditional simplified design and simulation methods often breaks in the test verification, which is much different from the expectation. Therefore, according to the contact numerical algorithm of the software, this paper considers the nonlinear characteristics of suspension strength in modeling, conducts electrical test and simulation benchmarking with the production process of actual cold assembly of the factory, and finally summarizes the adjustment methods of various parameters and convergence characteristics of contact nonlinear analysis, and forms a set of nonlinear strength simulation analysis methods suitable for suspension systems. This method laid an important foundation for the subsequent lightweight design work, and the lightweight balanced suspension system after multiple rounds of simulation optimization successfully passed the bench and vehicle reliability tests, and the lightweight suspension was successfully put on the market and obtained great economic value.

With the popularization of intelligent vehicles, the safe driving of vehicles has been paid more and more attention. In this paper, aiming at the characteristics of large mass, high centroid and easy instability of commercial vehicles, combined with the curved scene of expressway, the lane change trajectory of commercial vehicles is planned. The B-spline curve is superior to Bezier curve and polynomial curve planning. According to the characteristics of curve lane change, considering the road constraint problem, the control points of B-spline curve are selected. The model predictive controller is designed for the target vehicle by planning a curve lane changing trajectory that conforms to the dynamic characteristics of the vehicle. Using Matlab/Simulink and Trucksim to build a joint simulation scenario, the planned trajectory is tracked. The results show that commercial vehicles can track the trajectory safely and efficiently for lane change.

In accordance with the regulations GB11567-2017 “Requirements for the Side and Rear Lower Protection of Vehicles and Trailers” and the lightweight requirements of the frame, the development indicators are defined, and the rear protection layout plan is confirmed through benchmarking analysis. Based on OptiStruct, the topology optimization design of aluminum profile beam and casting installation bracket is carried out to determine the conceptual model, and the detailed structure model of beam, installation bracket and transition bracket is determined according to the bending section coefficient and weight index. Based on the ABAQUS elastoplastic analysis method, the static simulation analysis of the detailed structure of the rear protection is carried out. At the same time, the bench test verification is completed. The results meet the requirements of the regulations, which proves the correctness of the optimization design and analysis method of the rear protection structure.

This study verifies a FSEC racing car cooling system model by using Fluent software. To minimize unnecessary calculations, a porous medium is used to substitute the cold-type fins due to the periodicity of the cold-type fins. In the overall system simulation, the turbulence model is proved by using the Reynolds number for the overall calculation to ensure realism. To discuss the necessity of installing cooling fans in the cooling system, a wind tunnel simulation of the cold vent is carried out in this paper. And the model is verified by comparing the bench test and the simulation results to judge the correctness of the simulation results.

Cast aluminum alloys are increasingly being used in key parts of automobiles. Establishing a failure model that is suitable for aluminum alloy castings is vital for vehicle collision simulation and damage analysis. This article determines the damage parameters of an A356 aluminum alloy under different stress triaxialities using a modified Mohr–Coulomb fracture model. It also introduces a GISSMO nonlinear cumulative damage failure model for vehicle collision analysis. The results of the study confirm that the established model can accurately reflect the failure and fracture behavior of the A356 aluminum alloy. Furthermore, when paired with wheel hub collision test results, the model demonstrates high accuracy and reliability in predicting the failure and crack propagation behavior of the A356 aluminum alloy.

The influence of structural adhesive on static strength, fatigue durability and impact performance under stripping, stretching, shearing and bending conditions was studied by combining simulation and experimental verification. Taking a BIW as an example, the influence of structural adhesive on the structural performance of the body was also studied. Combined with topology optimization, less structural adhesive distribution was achieved to obtain better structural performance. On this basis, lightweight design of the body was carried out. Ultimately, a weight reduction of 11.6 kg was achieved for the BIW, with a reduction of 102 solder joints. The torsional stiffness, bending stiffness, and torsional modal frequency were significantly improved, while the bending modal frequency remained basically unchanged.

The impact mechanism of the front windshield on the torsional stiffness of the body in white (BIW) was studied by using a simplified windshield model, and the lightweight design of the front windshield was performed. Firstly, the influence of the front windshield on the torsional stiffness of the BIW was verified, and the mathematical model and simplified finite element model of the windshield stiffness were established. It is concluded that the shear stiffness of the front windshield is the main factor affecting the torsional stiffness of BIW. Secondly, the relationship between the windshield stiffness and the torsional stiffness of the BIW was established, and the influences of the elastic modulus and thickness of different types of windshield on the torsional stiffness of the vehicle body were quickly analyzed using the simplified model. Finally, two lightweight design schemes were carried out for the windshield. The accuracy of the simulation models was verified by experiments. The two schemes have achieved weight reduction by 17.3% and 41.4%, respectively, under the requirements of the stiffness and mode of BIW and the pedestrian protection.

Autobody lightweight design, on the premise of ensuring vehicle safety and comprehensive performance, is a high-dimensional and highly nonlinear Multidisciplinary Design Optimization (MDO) problem. However, there are problems such as low accuracy of the approximation model and poor convergence accuracy in engineering research. To solve the above problems, this article proposes an MDO design method combining an improved Gaussian Process Regression (GPR) model with a dynamic relaxation factor in Analytical Target Cascading method (DFATC). To improve the accuracy of the GPR approximation model, the combined kernel function is used instead of a single kernel function to have the advantages of multiple single kernel functions, and the particle swarm algorithm is used to adaptively optimize hyperparameters. To achieve high convergence accuracy, the dynamic relaxation factor is introduced to adaptively improve response deviation constraint in ATC to meet the convergence requirements. Finally, the crashworthy structure of the front body is designed using this novel MDO method, and the results show that the proposed method can solve complex engineering problems with high efficiency and accuracy.

This article provides an overview of the aerodynamic development process of Voyah’s first sedan, zhuiguang bev version as an example. Firstly, the target is set through competitive analysis and from the vehicle range requirements. Secondly, the shape optimal design of the BEV is conducted to reduce the drag coefficient (Cd) value by CFD simulation and clay model wind tunnel test. Then, Automobile accessories is used to reduce the Cd value, which include assembling the active grille shutter (AGS) and aerodynamic rim and optimizing the bottom plate and wheel spoiler. Finally, through the wind tunnel test of the prototype car, to achieve the goal of wind resistance coefficient.

This paper introduces some thoughts about the aerodynamic pressure center of automobile. Firstly, the simplification to a center point of the force system in space is introduced, and then the force on the vehicle surface is analyzed. The aerodynamic pressure center is verified by the results of the wind tunnel tests of real vehicles and CFD simulation results. At last, the equations of the central axis of the force screw and the central line of the wind pressure are derived, and the CFD simulation results are used to verify the correctness of the theory.

The fatigue life of body welds plays a very important role in durability. In this paper, the body-in-white of a domestic commercial vehicle is used as the research object and the actual road test results are used as the benchmark to calculate the road test damage threshold. The fatigue analysis method based on force and stress was used respectively, and the parameters of the stress-based fatigue method of body weld joint were obtained by comparing the field test threshold. It is found that when the number of finite element nodes around the welding core is not less than 16, and the welding wire distance of 0.3 mm is used, the simulation results are closer to the real road test results. At the same time, it was found that the wire bond distance had little effect on the damage results.

The fatigue durability problem of the chassis has become a focal point in recent years for the research and development of commercial vehicles. However, traditional load measurement methods cannot directly measure the boundary loads of the chassis. To address this issue, this study focuses on a certain light-duty truck and utilizes the CRG road model as an excitation source to construct a full-vehicle multibody dynamics model with the FTire tire model. This leads to the establishment of a Virtual Proving Ground (VPG) system to extract fatigue loads on the vehicle components. Experimental load spectrum data is obtained through road spectrum acquisition tests conducted at an automotive test facility. By comparing the test data with simulation data, the results show good agreement in the time domain and relative damage characteristics, confirming the accuracy of the virtual proving ground simulation results. Finally, fatigue analysis methods are applied to the chassis model based on the virtual proving ground simulation data, identifying high-risk areas and performing optimization to ultimately eliminate the high-risk regions of chassis fatigue.The virtual proving ground technology not only enables early acquisition of fatigue loads on vehicle components for fatigue analysis and optimization but also provides high-precision load spectra extraction.

A thermal fatigue (TF) test bench for V-shape specimen was established successfully. Based on different test schemes, it was observed that the fatigue life of V-shape specimen decreased with increasing cooling time. Then, the finite element analysis (FEA) model was developed, the max value of equivalent plastic strain amplitude (ΔPEEQ) is 0.17%, observed on the inner surface of V-shape area, which corresponded to the area with cracks on the real specimen. Moreover, the program was written by python to predicate the crack locations and TF life. The calculated life of critical point of V-shape specimen was 4071 cycles, corresponding to the test value of 3963 cycles. Finally, the research achievements were applied successfully in a product of catalytic converter. The minimum value of the TF life occurred at the inner edge of the intake clamshell, with a life value of 2775 cycles, meeting the reliability requirement.

The outer handle of the door in the car is an important part of man-machine interaction. The unlocking process directly affects the customer experience, which in turn affects the reputation and positioning of the production. This paper analyzes and optimizes the spatial arrangement and structural parameters of the internal components of the system that affect the unlocking stroke of the outer door handle. Using the mathematical model of the outward opening movement, taking the lock body, the exterior door handle, and the door lock outward opening lever as the research objects, the movement process model of the side door lock system in the process of opening the door with the outer handle is established. With the analysis of the model, the main factors affecting the unlocking stroke of the outer handle are determined. At the same time, with the 1/2 implementation of the four-factor and five-level secondary rotation center combination analysis method was adopted. Through the optimization analysis of the evaluation indicators such as the exterior door handle unlocking stroke ratio and the handle limit stroke, the optimized outer handle unlocking stroke ratio was finally obtained as 0.67, and the remaining stroke of the lock body is greater than 0.5 mm, which meets the requirements of the design specification and provides a reference for the design and development of future automotive products.

Utilizing the theory of ultrasonic acoustic elasticity, a field-test method for evaluating the tightening characteristics of wheel bolts was conceived. By designing specific testing items, the axial force degradation pattern during wheel bolt tightening was discerned, and the impact of various dynamic driving conditions on axial force degradation was identified. Factors such as test part temperature and environmental temperature on the results were analyzed. From these insights, an equivalent axial force calculation formula tailored for field-testing of wheel bolt tightening was derived. A streamlined segmented operating condition testing approach was devised, and its axial force measurement consistency was verified against the traditional method. Through evaluating axial force alterations across different road conditions for average users, a comparative relationship between the wheel bolt tightening field-test and routine road conditions was deduced. The results indicated that the segmented wheel bolt tightening force field-test, using the ultrasonic method, is compliant with standard assessment criteria.

In order to solve the problem that multiple system integration tests cannot be carried out due to the lack of electric drive systems in the early stage of vehicle development, a virtual reality combination test scheme based on the digital twin model of electric drive systems was proposed, and a method for constructing the digital twin model of electric drive systems was presented. The calculated and measured values of the digital twin model of water outlet temperature of electric drive systems under different operating conditions were compared, with a maximum error of only 4.7%. This digital twin model has the characteristics of accuracy, efficiency, and stability. Based on this model, multiple system integration virtual reality integration testing can be completed in the absence of an electric drive system, and vehicle thermal management performance can be evaluated at the early stage of vehicle development.

When a narrow vehicle drives on a curve route, it is at risk of rolling over due to the centrifugal force applied to its yaw motion. Therefore, an active tilting vehicle should tilt in the opposite direction of centrifugal force when the vehicle is yawing. That the active tilt motion of the vehicle synchronizing with its yaw motion can improve the steering and roll stability of the vehicle. But the tilt motion is slower than the yaw motion due to the tilt damping of the suspension. In order to synchronize the tilt motion with the yaw motion of the vehicle, an approach that controls the tilt angle by the prediction of the yaw rate was proposed. A back-propagation natural network and a recurrent neural network were ensembled to predict the yaw rate of the vehicle. A prototype is manufactured based on the proposed approach. When the prototype is driving on “S”-curve routes and “C”-curve routes, the average lag time of tilt angle is reduced to 0.09 s. The synchronization is better in “C”-curves that are closer to actual traffic. Compared with the tilting angle control approach without the prediction, the proposed approach reduces the average lag time by 78.01%. The size of the network model used in the prototype is 3207 kB, so the network model can be embedded in a variety of devices. Experiments show that the approach can effectively synchronize the tilt motion with the yaw motion of the vehicle. Experiments also show the practicability of the proposed approach.

Distributed drive vehicles, being typical over-actuated systems, hold immense potential in enhancing vehicle maneuverability and safety through the utilization of the four-wheel independent drive capability. This paper introduced a torque vector control (TVC) algorithm aimed at maximizing tire force utilization for each wheel and achieving coupled control of sideslip angle and yaw rate. The research begins by analyzing the steering hysteresis characteristics of the vehicle, proposing a crucial yaw rate to establish a dependable stability boundary. Employing a phase portrait analysis method, it determines the sideslip angle stability boundary and computes the target value essential for configuring the reference targets within the TVC algorithm. Subsequently, a hierarchical torque vector controller is devised, comprising three distinct components: The longitudinal force distribution layer focuses on achieving the road adhesion limit concurrently for the front and rear axles, optimizing their capabilities. The additional yaw moment control layer utilizes model predictive control to generate supplementary yaw moments for the vehicle. The wheel torque regulation layer integrates additional yaw moments, longitudinal drive force distribution requirements, and other constraints to efficiently distribute four-wheel torque based on the optimal tire adhesion rate. Ultimately, the effectiveness of the TVC algorithm is rigorously assessed through a representative experimental scenario.

Knock is an abnormal combustion in the engine cylinder, which reduces the engine power output and fuel economy, and worsens the engine emissions. In this research, the knock of turbocharged engine was divided into conventional knock and super knock. The knock judgment was mainly based on the knock signal collected by the knock sensor. The knock detection strategy mainly adopted CIC (Cascade Integrator Comb) filter, FIR (Fine Impulse Response Filter) filter, and offset compensation, which were used to process knock signals. Obtaining the characteristic quantity r_knock was used to judge whether knock occurs under the current working condition. The value of this characteristic quantity showed the current knock level. The result described that no knock misjudgment occurred under steady-state and transient conditions, and omission judgment rate was less than 5%. This meets engineering error requirements. The knock control was accurate and no limit torque and no super knock caused by abnormal identification, under extreme working conditions. In simulated preignition working points, preignition can be identified. Delaying Spark angle, fuel enrichment, temporary reduction of air, fuel cut-off and continuous gas reduction can effectively eliminate knock.Nowadays, turbocharging direct injection technology has been widely used in engine design and production because it could provide very flexible stratified combustion, ensure combustion adequacy, improve power and fuel economy, and achieve fuel saving and emission reduction. However, the application of this technology also increased the probability of engine detonation. [1] Knock is an abnormal combustion in the engine cylinder. The combustible mixture in the combustion chamber ignited spontaneously or was ignited by other non-sparking plug heat sources. This caused suddenly non-long lasting vibration and abnormal noise of the engine. This abnormal combustion reduces fuel economy and engine power, and worsens the engine emissions. When abnormal combustion cannot be effectively controlled, knock will have adverse effects on engine hardware, how terrible, spark plugs, valves, pistons, etc. will be damaged. [2] When the engine works at the knock critical point or has slight knock, the engine can obtain better power and economy. Therefore, the spark angle of the engine should be controlled at the critical state of knock; However, in the actual work points, the knock critical state will change with the change of engine operating conditions and fuel quality. In order to make the engine work in the critical state of knock, it is necessary to control the knock. The knock level is monitored in real time by the knock sensor installed on the cylinder block [1–3].In this paper, knock was divided into conventional knock and super knock. The control methods of these two types of knock were studied. It was found that the way of using the decrease spark angle could effectively eliminate the conventional knock, but this way was no longer applicable to the super knock caused by preignition. When super knock occured, it could be treated by reducing air or enriching fuel. The result described that no knock misjudgment occurred under steady-state and transient conditions, and omission judgment rate was less than 5%. The knock control was accurate and no limit torque and no super knock caused by abnormal identification, under extreme working conditions. In simulated preignition working points, preignition can be identified.

By stating the key essential technique urgently needs to be breakthrough of super complex system architecture in the developing strategy of smart vehicle, bringing that the Advanced Driving Assistance System (ADAS) is the best instance to reach this developing strategy target. Abstracting a computer system model from ADAS, bring up the key basic technique it is to solve ADAS efficient concurrency task in complex system based on Scalable service oriented middleware over internet protocol (SOME/IP), which means “Rapid Controller area network (CAN) data collection” and “Dispatching CAN instruction on time”. Simplifying the super complex system architecture of vehicle to be as a small Automotive Ethernet (AE) model, by using Common application programming interface (CommonAPI) to design and implement the Application Programming Interface (API) of concurrency task under Service Oriented Architecture (SOA) frame thinking, coding to implement API and verifying functions of concurrency task, by through result of test program to evaluate API executing performance. Theoretically, the API designed by “CAN signal oriented” thinking brings massive context interaction just as going in and out of AE stack, which takes more AE bandwidth too. Optimizing the API of concurrency task by using “CAN signal set service” thinking, programming and testing again, the test result shows that the optimized API descends the massive context interaction and obviously improves AE bandwidth usage. By using “theory guiding practice” this way, at last this paper successfully implements efficient concurrency task this study goal.

As one of the important directions for the future transformation and upgrading of global automobiles, intelligent connected vehicles (ICVs) are currently in a critical stage of rapid technological evolution and accelerated industrial layout. Realizing legal and regular operation is the crucial and final goal of the commercial application of the ICV industry. The huge commercialization prospect of ICV has attracted massive participation of enterprises. With the further acceleration of the transformation of the autonomous driving industry structure, OEMs attach great importance to the research and development of ICV technology. They are devoted to mass-producing vehicles equipped with L3 or higher autonomous driving technology in the future. At the same time, selecting a few application scenarios to break through fully is the choice for most autonomous driving companies to promote the commercialization of intelligent connected vehicles. Forming corresponding solutions and products according to the characteristics of various application scenarios and technological evolution trends and realizing industrialization and large-scale development has become the consensus and common goal of the staged development of the industry. China’s ICV industry has run parallel and is leading the world in some fields. Driven by technology, capital, and policies, China’s ICV industry constantly advances from commercial pilots to large-scale applications. This article provides a reference for the commercialization of China’s ICV industry by analyzing the status, key elements, and challenges of China’s ICV commercialization.

The used vehicle trading market is a huge market. In which the value retention rate is an important indicator that directly affects the transaction price of vehicles and the interests of buyers and sellers. With the continuous development of the used vehicle market, how to accurately predict the value retention rate of used vehicles has become a matter of great concern. It is of great significance to vehicle owners, buyers, financial institutions and other related aspects.The traditional prediction method of used vehicle value retention rate is mainly based on regression model and statistical analysis method. It is necessary to manually extract features and build models, which has problems such as low prediction accuracy and difficult to scale. The pre-trained language model can be trained through large-scale text data to learn the grammar, semantic and contextual information of the language, so as to generate high-quality text representation vectors that can better express the meaning and information of the text. Therefore, by integrating the pre-trained language model, the value retention rate prediction model will have better generalization ability and higher prediction accuracy.In this paper, BERT and ELECTRA pre-trained language models are used to train and fine-tune on self-constructed used vehicle related text datasets and resulting in high-quality text representation vectors. Based on the effect verification, this paper also uses traditional machine learning algorithms to predict the value retention rate, and compares the results of the three. Experimental results show that the method combined with pre-trained language model can significantly improve the accuracy of the value retention rate prediction. Especially it performs well when dealing with large amounts of complex text data such as vehicle reputation. Provide new ideas and methods for intelligent data analysis and application.

Since Facebook rebranded itself as Meta, the metaverse concept gradually cooled, and it is time to view the essence, value, and specific applications of the metaverse from a rational perspective. Cars play a crucial role in massive application scenarios, bridging the virtual world with the real one and serving as the first arena for metaverse applications. Some stakeholders in the automotive industry can already capture real business benefit from the technologies designed to enable the metaverse. From a perspective of the whole industrial chain, this study analyzes the potential application scenarios for the metaverse in the automotive industry, makes a specific analysis of some critical scenarios such as AD virtual test, virtual plant, user community, and smart cockpit, and compares scenarios from multiple dimensions to help automakers define strategies for different scenarios. Finally, this study proposes the roadmap for the metaverse to develop in the automotive industry, which requires joint efforts of all industrial participants to progress from improving links of the industrial chain to connect all scenarios in the metaverse and ultimately integrate metaverses of different industries for co-development, sharing, and co-governance of the virtual world.

This paper interprets and analyzes the scene theory in the field of automobile design, and summarizes the basic characteristics of the scene theory in the field of automobile design. The SBP (Scene Behavior Plan) car scene decomposition model based on the scene theory is proposed, which decomposes the user story into a combination of several scene modules, and converts it into quantifiable parameters or parameters that can be subjectively evaluated and assigned, finally forming an empirical evaluation scheme for the user story. At the same time, combined with the gray relational evaluation model, the evaluation method based on the user’s vehicle scenario is given. Finally, a case is used to illustrate the decomposition and evaluation process of vehicle use scenarios.

QFD tools model as to carry out customer demand oriented important tool for product development, applied more and more often in the development of new product innovation process, to enhance customer satisfaction, improve the market competitiveness of products, and to product development business success. But in the process of tool use, industry appeared to be too subjectively into straight evaluation, there is no detailed grading basis and standards. For this reason, this article is based on QFD model direct score in the four evaluation dimensions objective research, work out the hierarchical multilevel index system, the quantitative criteria and operation rules of QFD tool for new product development model to promote the convenience and support.

Two kinds of emission equipment, FTIR and MEXA, were jointly used to measure unconventional and conventional pollutants of light-duty methanol vehicles, respectively. In the test, several different test methods were operated in order to compare the exhaust emissions of the test vehicles. Specifically, the effects of different test conditions, temperatures, and concentrations of methanol gasoline on the exhaust emissions such as ammonia gas (NH3), methanol (CH3OH), acetaldehyde (CH3CHO), carbon monoxide (CO), and particle number (PN) were investigated. By analyzing the test results, the patterns of emission and fuel consumption of light-duty methanol vehicles were summarized. This study offers a deeper understanding of the patterns by which conventional and unconventional pollutants were discharged from mechanol automobile.

Diesel engine blended with biodiesel is an important measure to solve the poor combustion conditions and performance degradation of heavy diesel vehicles in plateau areas, but it may also bring different emissions effects. To explore the impact of mixing biodiesel or pure diesel on emissions at different altitudes, this study takes an N3 truck as the research object, and conducts emissions tests at altitudes of 0 m, 2000 m and 2400 m, respectively, using diesel and blended diesel mixed 7% biodiesel. The emission characteristics of carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOX), and particulate emissions number (PN) were compared in the aforementioned environments. The results show that pollutants exhibit a clear pattern with VSP apart from NOX; Altitude and the mixing of diesel and biodiesel has little impact on CO2emissions; Blending biodiesel can effectively reduce emissions of CO caused by high altitude, but both blending biodiesel and increasing altitude will increase NOX and PN emissions.

OVC-HEVs typically use the NIRCO systems to achieve their unique evaporative emission control strategies. This paper constructs the following OVC-HEV evaporative emissions calculation model: Based on the Clausis-Clapeyron equation and the ideal-gas equation, the pressure changes inside the sealed fuel tank and the evaporative emissions of fuel tank vapors are described; Then describe the adsorption and desorption equations of the carbon canisters through the results of the bench tests, and obtain its relationship with the initial working capacity and effective volume of the carbon canisters. Finally, based on the above sections, a NIRCO system evaporation emission calculation model for OVC-HEV is obtained, as well as a quantitative analysis of various influencing factors. Based on statistical data such as local climate temperature and driver usage, this model can be used to estimate the evaporative emissions of OVC-HEV fleets.

PN emissions result has been clearly required to be less than 6 × 1011 in CHINA 6 regulations. The PN emission challenge is more difficult without GPF exhaust system. Taking vehicles equipped with China’s Top Ten engines, BAIC 1.5GDIT engine, and without GPF exhaust system as the research object, this research is focused on analysing the PN emissions of vehicles in the WLTC emission cycle under cold engine, warm engine, and high-speed heavy load conditions. Optimize the cold start air fuel ratio; Scan the cold engine injection mode, VVT, rail pressure, and ignition timing; Optimize the injection phase and transient fuel control during warm-up conditions; Optimize the injection mode under high-speed and heavy load conditions. The PN emission results were all within 50% of the limit value of the CHINA 6 limits used the EMS control strategy studied in this article, verified by different batches of test samples without GPF exhaust system.

With the rise of a new round of technological revolution and industrial transformation, new technologies such as the Internet of Things, cloud computing, big data, and artificial intelligence are rapidly developing and widely applied in various fields, leading the digital transformation and upgrading of various industries. After over a century of development, the automotive manufacturing industry has become one of the most automated and intelligent manufacturing industries. However, facing the increasingly competitive market environment, how to effectively utilize new digital technologies to further enhance the maintenance efficiency of production equipment and reduce maintenance costs remains a pressing concern for various automotive enterprises in their production operations. This article primarily introduces the meaning, implementation methods, and exploration and practice in automobile factories of equipment predictive maintenance technology.

This article introduces the construction technology of the bottom hammering cast-in-place piles. This set of technologies includes internal impact technology, pressure grouting technology, pile testing technology, and the design of specialized multifunctional pile pipes. This technology can make up for the limitations of static pressure pile pressure, and it is difficult to achieve the shortcomings of high bearing capacity, as well as the problems of high noise, vibration, and easy damage to the pile body caused by hammering. This construction method can adapt to various geological conditions such as soft and hard soil layers, and improve the strength of the pile body and the bearing capacity of a single pile. At the same time, this article conducted on-site static load tests on single piles formed by different construction methods. Through comparative analysis of on-site static load tests, the bearing mechanism and advantages of bearing behavior of internal impact grouting piles were explained.

In the R&D and testing of vehicle door products, the assembly level abnormal noise OTS approval test is easier to ignore, so in the vehicle certification stage or after mass production and marketing, NVH quality problems such as door glass lifting abnormal noise occasionally occur, at this time, tracing quality problems forward often results in a large cost loss. At present, the resources for component level and vehicle level NVH testing and certification equipment on the market are relatively perfect, while the resources for assembly level NVH test equipment are less. Faced with this situation, this paper designs an automotive door assembly abnormal noise test equipment based on high and low temperature environment, the equipment can simulate the installation state of the real vehicle to the greatest extent, and has an upper computer and lower controller based on wireless architecture design, as well as a human-computer interaction system written based on LabView software. Good simulation, strong expandability, stable and reliable.

This paper mainly introduces the intelligent bumper matching and sorting system which has been developed by Dongfeng Nissan in Wuhan factory. Based on the full color difference measurement of robot, the system designs advanced software algorithm, which realizes the precise matching of car body and bumper color difference value for the first time in the industry. Through the analysis of the time and the enumeration of the path comparison, the system picks out the optimal bumper which ensures the FIFO and delivery efficiency. In the application of the project, through equipment and process innovation, for example flexible fixture, AGV automatic sorting, error and mistake proofing system, and so on, we solve a variety of issues brought by new technology. The system greatly improves efficiency and reduces costs, and highlights design concept of the flexible and intelligent.

The mobility of the omnidirectional movement platform based on Mecanum wheels is excellent, and it can achieve movement in multiple directions such as forward, lateral, rotation, and diagonal. Therefore, it has broad application prospects in the manufacturing industry and warehouse logistics automation field. This paper proposes a feasible design method and model for the omnidirectional movement platform based on the Mecanum wheel motion theory model, and independently designs and develops an AGV omnidirectional movement platform based on Mecanum wheels, which is applied in actual mass production.

The calculation method of Kingpin Inclination Angle of Automobile Wheel Suspension Parameters can not be expressed explicitly, and it can only be infinite approximation to the real solution by repeated trial calculation based on mathematical model. This also determines that the Kingpin Suspension Parameters of the vehicle can not be measured directly, and can only be calculated by simplifying the mathematical model. Using gradient analysis to select data points combined with the experimental test method to analyze the correlation between the measurement value of the four-wheel aligne instrument and the set value of the four-wheel aligner, the system analyzes the changing trend of the measurement point. Select effective measuring points according to the analysis results, with a small amount of measurement data can represent the deviation characteristics in the whole range, providing a scientific basis for the selection of wheel suspension parameter detection points, while greatly reducing the testing workload so that the formulated standard has a strong executable, and provides a reliable basis for the vehicle factory inspection and performance testing data measurement points scientific and reasonable selection.

Focusing on the development of oil on-line monitoring and intelligent diagnosis system, taking automotive stamping press equipment as the research object, from the aspects of system software architecture, hardware architecture and system function, a company-level oil on-line monitoring and intelligent diagnosis system driven by big data is planned and established; The system is designed and developed from the aspects of monitoring objects and monitoring parameter setting, monitoring unit design and development, oil circulation unit design and installation, diagnosis model improvement, intelligent analysis and diagnosis, trend prediction, visualization and system integration; In order to realize the closed-loop operation and popularization and application of the whole system, the management mechanism of oil monitoring and intelligent diagnosis system is developed, and the real-time monitoring of oil condition is realized. At the same time, through the intelligent diagnosis, analysis and prediction of data, the workload of oil consumption and monitoring of equipment is reduced, and the predictive maintenance of equipment is assisted. Improve the quality of equipment operation, ensure the running time of equipment, and then ensure the production capacity.

To solve the problem that the chassis load of loaders is difficult to obtain, a chassis load dynamic estimation method for distributed electric drive loaders is presented in this paper. Firstly, according to the characteristics of the external load, two estimation modes for the bucket’s external load are presented, which are based on longitudinal load and center of gravity (COG) of the material respectively. Secondly, considering the influence of material flow on identification of material’s COG position and mass parameter, variable forgetting factor recursive least squares (VFFRLS) algorithm is employed. And then, the vertical load of loader chassis is calculated by analyzing the straight shoveling operation. Finally, to verify the algorithm in this paper, co-simulation of Adams and EDEM is used to generate the reference curve. The results show that VFFRLS can enhance the convergence speed with improving accuracy to some extent, and is more suitable for the identification of material parameters in loader operations. Compared with the results of co-simulation, the Normalized Root Mean Squared Error (NRMSE) of front and rear wheel load is 2.48% and 4.60%, respectively. Therefore, the effectiveness of the algorithm is verified. This research provides a basis for distributed electric drive system control and automatic operation of loaders.

The pursuit of more efficient and cleaner combustion has become the driving force behind the development of the internal combustion engine, while the combustion technology with higher efficiency and lower carbon emission provides a strong competitiveness for the power products in the new the new market and policy context. Geely's DHE engine with BTE of 43% has been put into mass production in 2022. In order to pursue higher engine thermal efficiency, a new type of engine has been developed synchronously. A lean-burn single-cylinder engine was taken as the prototype to optimize the combustion system and jet ignition system with an active pre-chamber. Subsequently, the combustion system of the single cylinder engine is transplanted to the multi-cylinder engine with the same cylinder diameter as the mass production model, which makes the newly developed ultra-efficient multi-cylinder engine feasible for mass production. Ultra-high compression ratio, Miller cycle, efficient supercharging system, intelligent thermal management and friction reduction technology are adopted to further improve the effective thermal efficiency of the engine. Finally, brake thermal efficiency of engine achieved more than 46% of the international advanced level, while the NOx concentration before catalytic converter could be controlled within 250 ppm. At the same time, the engine is equipped with a special after-treatment system for lean-burn technology, so emission would meet the requirements laws and regulations. In the future, the engine will realize full map lean-burn combustion to reduce the cost of after-treatment. The engine serves as an important technical reserve for Geely's future continuous low-carbon technology.

By using a visual single-cylinder transparent engine and thermodynamics test bench, this paper aims to research the suitable injector for a high thermal efficiency (BTE 42%) TGDI gasoline engine. It focuses on the matching with a high tumble ratio combustion chamber with different spray angle, spray target position, as well as the influence on the characteristics of in-cylinder flow, combustion and emissions, to find the suitable injector for a high tumble ratio of the combustion chamber. The test results show that a 5-hole injector has the best matching with the combustion chamber and in-cylinder flow, which can effectively reduce the risk of spray impact piston head and cylinder wall. Combined with the multiple injection strategy, higher power, torque and lower part-load fuel consumption are achieved, as well as optimal emissions.

The effect of super lean burn on engine performance was studied on a self-developed pre-chamber multi-cylinder engine in this paper. The main work is to develop a pre-chamber multi-cylinder engine based on the high efficiency pre-chamber ignition and combustion system of a thermodynamic single cylinder engine, matching the special lean burn high efficiency turbochargers, and low friction technologies, achieved a brake thermal efficiency of 46.14% based on the engine bench test. This paper mainly analyses the effects of intake ports, intake camshafts and turbochargers of different design schemes on the efficiency, combustion in cylinder and NOx emission of super lean burn pre-chamber engine.

The traditional gasoline engine lubrication system generally adopts a series oil circuit layout. The series oil circuit layout has some inherent defects, which cannot be improved through the optimization of the oil pump or lubrication system parts. Moreover, the serial oil circuit layout is becoming increasingly unsuitable for various hybrid car application scenarios. Based on the limitations of the traditional lubrication system, a new layout of gasoline engine lubrication technology - Split Lubrication System is proposed. The improvement of these defects by split lubrication system is analyzed theoretically, and the application of split lubrication system in several Hybrid car scenarios is mainly discussed. By means of simulation, the friction work saving and fuel consumption reduction effect of split lubrication system are analyzed. Combined with a certain 1.5 T supercharged direct injection gasoline engine, the research on the industrialization of split lubrication system was carried out, and the application prospect of split lubrication system was analyzed through the aspects of fuel saving effect, technology maturity and cost.

In this paper, a mechanical supercharger intake system is developed for a 693 mL small twin-cylinder FSAE racing engine. Firstly, the target engine-related boost matching calculation was completed, and the mechanical supercharger was selected by combining the calculation results and simulation analysis, and the centrifugal mechanical supercharger model corresponding to the best matching result was determined. A one-dimensional simulation model of the mechanical supercharged engine was established by using GT-POWER software, and the optimal intake system geometry parameters were determined by multivariable simulation design. The power and fuel economy of the mechanical supercharged engine were significantly improved after the matched design. Compared with the naturally aspirated engine after restriction of flow, the torque is improved at all speed conditions and the 0.1 s throttle step input torque transient response is achieved.

The aerodynamic package plays a crucial role in the performance of FSAE race cars. Airfoils in race car design require careful selection and optimization for its role as the designing foundation of the front wing, rear wing, and other aerodynamic components. In this study, the selected airfoil is parameterized using Hicks-Henne function. Then, an automated airfoil optimization process adapting the non-dominated sorting genetic algorithm built in Isight, which combines Xfoil, MATLAB, and STAR-CCM+, is introduced. The optimized airfoil had a higher lift coefficient and lift-to-drag ratio of 148.23 at the targeted optimization attack angle. The optimized airfoil was then applied to a test car, which contributed to an increase by 24.38% in the lift of the front wing and 14.11% in the lift of the whole car. The proposed method can efficiently improve the aerodynamic performance of the airfoil, which lays a solid foundation for the subsequent aerodynamic development of the entire car.

This article is focused on the potential problem of inadequate heat dissipation performance in the powertrain system of FSAE race cars which adopt an overall monocoque structure. It aims to design an integrated thermal management system with slanted dual radiators that match the aerodynamic design and incorporates an oil cooler, to achieve better thermal reliability and stability under high load conditions. During the development process, various studies were conducted to coordinate and unify the thermal management system and the side aerodynamic devices, including the correlation between different radiator layouts, geometric parameters, and heat dissipation performance, the gain in heat dissipation performance by the structural design of the side aerodynamic devices, the design and simulation of the engine thermal management system pipelines, and the performance verification of the thermal management system during engine bench tests and road tests.

The wheel system is an important part of the chassis structure, involving suspension, transmission, braking, etc. The wheel system is the bridge between the racecar and the ground through the tires, and it is the unsprung mass of the whole racecar, which is prone to failure under extreme working conditions with severe loading. Therefore, it is of great importance to do research on its lightweight, stability, and service life, which can improve the chassis dynamics, transmission stability, and safety level of the racecar. This paper mainly focuses on the design of the racecar wheel system based on spline connection and research on the service life of the spline, including how to determine the spline parameters, surface treatment process, and the influence of the rim center nut preload on the spline. Then, combine with lightweight consideration, to determine the suitable structure design parameters of the spline. The safety factor is more than 1.8, the service life of the spline connection is more than 8600 km, and the weight is reduced by nearly 1.5 kg compared to conventional friction sub-designs. By analyzing the service life of the spline connection, the lightweight of the wheel system structure is improved while ensuring the service life, and the convenience of disassembly and installation is enhanced.

This paper is based on the rules and requirements of Formula Student car competition in China to design a single shell frame, its purpose is to get a certain advantage in the increasingly fierce dynamic race competition. In the FSCC, the traditional steel pipe truss frame gradually loses its competitiveness in the competition, and it is difficult to achieve a significant breakthrough in lightweight. The monomer shell optimized based on CFRP design has many advantages, such as light weight, strong integrity, excellent stiffness, anti-corrosion, etc., which is the reason why most fleets choose to use monomer shell. The theoretical mass of the mono-shell frame designed in this paper is 28.4 kg, and the torsional stiffness is 3728.1 Nm/°, which is 11.56 times of the roll stiffness of the suspension, which can help the suspension quickly realize a more stable load transfer and distribution of the front and rear axles when it overturns and rolls. At the same time, this paper also optimizes the design condition according to the actual mode frequency to meet the design requirements of safety, lightweight and reliability.

The paper focuses on the chassis of the Dongfeng HUAT Team's 11th generation car and conducts a comprehensive study on its vibration characteristics using the finite element method. Firstly, a finite element model of the chassis structure is constructed using CATIA. Subsequently, the modal analysis is performed by applying ANSYS technology to calculate the finite element analysis results. Furthermore, the dynamic characteristics of the chassis are explored in greater depth by investigating the impact of engine vibrations on the chassis structure and examining the interaction between the chassis design features and the race car's drive system. Finally, random vibration analysis is conducted using ANSYS to further validate the theoretical and simulation errors. This research provides valuable insights and a solid foundation for effectively addressing mechanical vibration issues in tubular chassis systems. The findings have significant theoretical significance and practical implications.

Multibody simulations are widely implemented in vehicle dynamics engineering due to their fast and reliable results. Multibody simulation serves as a very useful research and development tool for Formula Student teams. This paper focuses on the development of a multibody simulation for a Formula Student vehicle at the University of Bath, using IPG CarMaker. The vehicle model used is the Team Bath Racing (TBR) 17 racing car, was compliant with Formula Student regulations. A detailed multibody model was constructed, and its dynamic performance was tested against a real vehicle through spring and damping tests on tracks. The validation demonstrated the reliability and feasibility of the model. Based on these results, several simulations were conducted to compare the vehicle dynamics with parameter changes. The simulations provided valuable data for optimizing the current vehicle and guiding future development of new racing vehicles.

The FSAE brake system is a hydraulic dual-circuit system that maintains a constant braking force distribution coefficient. This paper focuses on designing various parameters of the braking system, including the braking force distribution coefficient, in accordance with competition regulations. By analyzing the braking system and employing a simplified model of the racing car, multiple parameters are devised. Utilizing MATLAB’s Fmicon optimization function and incorporating suspension characteristic parameters, this method optimizes the braking force distribution coefficient. The aim is to achieve a braking efficiency exceeding 80% under a road adhesion coefficient of approximately 1. The obtained results guide the selection of an appropriate brake master cylinder, brake caliper, and other essential parameters, culminating in the determination of maximum braking deceleration and braking distance.

With the rapid popularization of new energy vehicles around the world, Chinese college formula racing competitions are increasingly receiving widespread attention from college students. As the core component of electric racing cars, the thermal safety of lithium battery systems deserves in-depth research. Battery thermal modeling, real-time and effective thermal monitoring, and thermal management are crucial for the safe, efficient, and reliable operation of battery systems. This article will take the battery system of pure electric racing cars as the research object, combined with FSEC dynamic competition, through experimental and theoretical combination, select battery cells and design modules. A new battery box is designed through CATIA, and the best battery box is obtained through ANSYS static and thermodynamic simulation. The rationality of the battery box is verified through experiments and actual vehicle testing. Through a series of experiments, it is found that: The consistency of each battery cell is relatively stable. In terms of capacity, the capacity of the actual vehicle decreases by 5% during running, which can effectively complete the cycle durability working condition. According to the temperature chart, in an environment of 20 ℃, the temperature rise of the electric vehicle during running does not exceed 25 ℃, and the temperature difference is 4.5 ℃, which is consistent with the simulation model of battery box heat dissipation and meets the requirements of good heat dissipation.

The assembling of the IWM (IWM) leads to a sharp increase in unsprung mass. In order to study its impact on the handling and ride comfort of IWM vehicles, a three-motor four-wheel drive (4WD) vehicle is taken as the study object, and a multi-body dynamic simulation model is established by ADAMS for the analyzing of handing performance of the vehicle. Results show that the increase of unsprung mass has little effect on handling performance under national standard routine test conditions. Based on MATLAB/Simulink software, the vibration model of 1/4 vehicle is established, and the ride comfort is simulated and analyzed in frequency domain and time domain, and the influence trend of vehicle parameters on ride comfort is quantified. Through disturbance sensitivity analysis, the influence degree of vehicle parameters on ride comfort is quantified, and the general rules of IWM vehicles design and ride comfort tuning are summarized, which has guiding significance for design and performance tuning of IWM vehicles.

In this paper, aiming at the body structure of pure electric vehicle, an optimization process of body structure is designed by adopting the method of topology optimization. Different topology optimization models are used, and it is verified that these models have different effects in vehicle body structure optimization. The results show that the power transmission path of the body structure, the joint structure of the key area, the weak area of the body, the effect of the reinforcements in each cavity and the material thickness distribution of the parts can be analyzed based on the topology optimization method in the design stage of the pure electric vehicle. Topology optimization methods can also perform lightweight analysis and optimized connections for body structures. Therefore, a topology optimization method flow that runs through each design stage of the body structure is formed. The method can increase the torsional stiffness of the car body to 40000 N/m.

Aiming at the problem of the low driving mileage retention rate and high energy consumption for thermal management of the battery electric vehicles under low temperature, this paper establishes the energy management system model and compares the energy consumption performance of the heat pump with motor waste heat utilization and the PTC heater under low temperature through simulation analysis. The results show that the energy consumption of heat pump system is positively correlated with the energy transfer efficiency of the heat flow path, and negatively correlated with the motor efficiency and the thermal load of the cabin. This paper further analyzes the operating efficiency trends of the two systems under different working conditions, and optimizes the thermal management strategy according to the ambient temperature and thermal demand. The results show that the energy consumption of the vehicle could be reduced by enabling the heat pump system and the PTC heater to operate within the high-efficiency region. Under the temperature of −20 ℃, the vehicle driving mileage with the optimized strategy is increased by 6.2% compared with the original strategy.

In low temperature environment, some parts of hybrid electric vehicles are affected by temperature, and the performance is completely different from normal temperature. This paper analyses and studies the telegraphic sound of a hybrid electric vehicle when starting at low temperature. First of all, we explored the boundary conditions of telegraph sound, and found that it was strongly related to temperature. We used vibration and noise equipment to locate the single parts, and then simulated the boundary conditions of the whole vehicle on the platform, and stably repeated the problem. Finally, we tested the size of key parts and found that because the rear bearing was pressed incorrectly, clearance was generated. The bearing was subjected to additional axial force, resulting in friction between the inner and outer rings of the bearing. In addition, at low temperature, lubricating oil viscosity becomes larger, bearing clearance becomes smaller, aggravating friction. After more than ten minutes of operation, the temperature rises, the lubrication becomes better, the bearing clearance becomes larger, and the problem is weakened and not perceived.

In 2022, the production and sales share of new energy vehicles in China exceeded 25%, but only in the first quarter, there were as many as 640 new energy vehicle fire accidents. The proportion of battery pack fires caused by side collisions was about 5%. In response to this safety hazard, through in-depth analysis of finite element analysis models, it was found that the threshold beam structure is an important energy absorption component for side collision conditions, playing a decisive role in battery pack protection. By analyzing the impact performance of threshold beams with different cross-sectional shapes and material types on the extrusion pressure and module invasion of battery pack molds during side impact, combined with weight and cost, the final selection of aluminum extruded profile threshold beams significantly reduced module extrusion pressure.

When one phase fault occurs in a three-phase permanent magnet synchronous motor (PMSM), maintaining system operation under fault conditions through fault-tolerant control algorithms can save redundant hardware and reduce volume, but unnecessary torque losses exist. To address this problem, this paper proposes a current control algorithm to reduce torque losses. Firstly, the torque equation of the motor under one phase fault is derived, and the relationship between the rotor position angle and the stator current under ideal torque is obtained, and an ideal stator current function relationship is designed. Then, the formula for the maximum current change of the actual motor is derived, and the rotor position angle change interval of the function is designed accordingly, and an effective average output torque index formula is designed to calculate the torque loss of the system. The fault-tolerant current control algorithm is experimentally verified on a motor controller based on the DSP chip TMS320F28335 and a 4-kW motor-to-trailer bench. Simulation and experimental results demonstrate that the algorithm can eliminate the excess target torque when the system experiences one phase fault, reduce the second harmonic contained in the torque, and effectively reduce the loss of output torque.

Proton exchange membrane fuel cell (PEMFC) with its zero emission and high efficiency is gradually being applied for clean transportation in China. In the quest to achieve higher economic efficiency of PEMFC hybrid vehicles, data-driven modelling methods are being developed in response to the complicated physicochemical phenomena of PEMFC systems. However, there is little research detailing the importance of balance of plants (BOP) features of the hydrogen anode, air cathode and cooling subsystems regarding PEMFC system efficiency at different driving styles. Furthermore, most research applies neural networks based on simulation and bench data rather than dynamic vehicle operation data, which leads to low robustness and unreliable practical results. Accordingly, this paper provides a novel application of the combination of a power-related feature extraction method, an unsupervised dimension reduction method, an unsupervised cluster method and an ensemble learning method, named PCA-Kmeans-XGBoost, to explore the relationship among controllable BOP features, PEMFC system efficiency and driving styles using real-time vehicle datasets. A case study of a PEMFC logistics vehicle is conducted based on the data at the size of 312,641 running in Shanghai in November 2022. The economic analysis explores the clustered driving styles with high power ranges and frequent power requests take 40.9% of the monthly hydrogen consumption per 100 km. The BOP features of the hydrogen and the air subsystems alternately rank top according to the characteristics of the three clustered power profiles. A comparative analysis and a verification study are performed to demonstrate the importance and the robustness of the proposed approach.

The electric transmission fluid (ETF) can improve the system efficiency of the electric drive unit (EDU). However, there is no unified method to evaluate the corresponding performance of ETF in the industry, which leads to misdirection in production development. This paper analyzes the factors affecting system efficiency, redefines the scope of system efficiency, innovatively introduces the power consumption of the electronic oil pump into the calculation of system efficiency, and redefines the calculation formula for system efficiency. The paper also explains the influence of ETF viscosity and heat transfer performance in the stator cooling process and suggests the need to set reasonable boundary conditions and operating conditions to comprehensively evaluate ETF performance. The paper examines the reasons for the low repeatability and discrimination in ETF efficiency testing and suggests a remedy by continuously gauging steady-state conditions and calculating the system efficiency in terms of work. The paper develops a test procedure for evaluating ETF and validates it by putting 12 ETFs to the test on the same EDU. The results show that ETF can have a significant impact on the system efficiency of the EDU under different operating conditions, cycles, and boundary conditions, especially in the common speed range of the vehicle and at low temperatures. Low-viscosity ETF can increase system efficiency by more than 1.5% compared to high viscosity reference ETF. The verification results demonstrate that ETF viscosity is not the only element affecting system efficiency and that comparatively low-viscosity ETF does not always perform better.

This paper proposes a data-driven energy management strategy (EMS) for a series hybrid electric tracked vehicle (SHETV). Firstly, according to the configuration characteristics of the SHETV powertrain, a simulation model for the development of EMSs is built. Secondly, combined with the design requirements, a global optimal EMS based on dynamic programming (DP) is developed. Then, the optimal control sequence is obtained and the NARX deep neural network is employed to extract the global optimal control rules and establish the mapping relationship between characteristic parameters and power allocation. Finally, the IC engine-generator power unit (IGPU) output power prediction model, battery state of charge (SOC) stabilizer, and low-pass filter are designed respectively, and the design of the data-driven EMS is completed. In order to verify the performance of the designed strategy, different driving cycles are used for offline training of the neural network and online verification of the effectiveness of the strategy. The simulation results show that the proposed EMS can effectively maintain the SOC of the battery and the fuel economy is improved by 10.89% compared with the EMS based on frequency domain power allocation.

Solid/liquid hybrid lithium ion battery is being one of hot topics in battery research owing to its higher energy density and safety in comparison with liquid lithium ion battery. However, disadvantages in fast charging and relevant lifetime are becoming the current technical challenges for hindering its commercial application. In view of this, one solid/liquid hybrid lithium ion battery with energy density around 270 Wh/kg has been developed which is devoted to improving overall performance parameters. Evaluation results indicated that the battery could be charged from 20% to 80%SOC within 19 min, and only 8% capacity fading was found during 1700 cycles with fast charging protocol. Furthermore, there were no fire/flame and no explosion in case of overcharge (1.3 times higher than upper cut-off voltage) and nail penetration (100%SOC). The aforementioned excellent performance was capable of meeting the strict requirements of traction battery for electric vehicles. Finally, it would optimistically have a significant impact in commercialization process that this solid/liquid hybrid lithium ion battery is in application to electric vehicles.

Fast and accurate fault diagnosis of electric vehicle power battery systems is important to ensure the safe and reliable operation of vehicles. For a long time, power battery fault detection methods have been widely studied and a rich literature library has been formed, in which the interval probability-based Shannon entropy method has been applied in many literatures. However, when we used real-world vehicle data from the cloud platform to validate and analyze the model, a large number of false alarm single cells are found in the diagnostic results, based on this, we further extended our research for the traditional Shannon entropy method. First, we analyze the abnormal voltage fluctuation fault and the fault diagnosis principle of this method. Then, the misdiagnosis mechanism of the method is explored in the context of two typical vehicle driving conditions. Finally, a solution to mitigate false alarms is proposed and its effectiveness is verified based on real-world vehicle data.

As the energy conversion unit of proton exchange membrane fuel cell (PEMFC), membrane electrode assembly (MEA) converted chemical energy into electrical energy under the action of catalyst. Platinum-based catalyst was still an irreplaceable catalyst for commercial PEMFC, and the platinum (Pt) loading in membrane electrode had became an important indicator of PEMFC performance evaluation. By improving the existing national standard method for testing the platinum loading of PEMFC membrane electrode, a microwave digestion pretreatment method for testing the platinum loading of PEMFC membrane electrode was developed. Compared with the national standard method, the new method not only improved the accuracy of the test results, but also greatly improved the test efficiency. The amount of reagent was greatly reduced. The method was more green, safe and environmentally friendly.

The energy crisis and environmental problems make the energy revolution urgent. Hydrogen energy, as green energy without pollution, has become a hot research topic. Hydrogen production by methanol steam reforming technology bypassed the current high cost of hydrogen transportation and storage, making it possible to use cheap hydrogen energy on mobile terminals. This paper analyzes the energy flow of BOP components, fuel cell performance, system efficiency, and economic feasibility of the methanol steam reforming 5 kW HT-PEM fuel cell system. Through energy flow analysis, the actual energy consumption and energy consumption distribution of each BOP component in the system can be understood, which is helpful for the subsequent improvement and upgrading of the control strategy and preheating mode of the system, and also has reference significance for the optimization of the selection of BOP components and the improvement of the overall system efficiency. The energy consumption of various types of heating rods in the system accounts for 90.8% of the total energy consumption during the preheating stage. In the power generation stage, the maximum fuel cell efficiency reaches 54.1% when the fuel cell output current is 20A, and the maximum system efficiency reaches 46.2% when the fuel cell output current is 33A. In terms of economic feasibility, the methanol steam reforming HT-PEM fuel cell as an automotive power system incurs fuel costs that are less than 30% of traditional fuel-powered vehicles.

Two separate electric motors are mounted on the rear axis of a hybrid vehicle. This configuration enables torque distribution between the rear wheels, which can generate torque rotating the vehicle. The front axis is driven by a hybrid system composed of an engine, an electric motor and a generator. Model predictive control is used in this paper to distribute the torque of the front axis, the rear left wheel and the rear right wheel. Some boundaries are regarded as soft constrains to avoid unsolved cases. This paper also proposes an evaluation method based on the improvement of understeering degree of vehicle steady-state response. Finally, compared with the method of average torque distribution, it effectively realizes the differential torque and assists the driver in steering, and reduces the steering wheel angle by up to 8% under the same path tracking target.

The driving performance of polar vehicle is affected greatly by the mechanical properties of snow. In order to explore the vertical displacement distribution and vertical force distribution of snow under the tracked vehicle, and to build the theoretical model of the interfacial force between track and snow and the dynamic model of tracked vehicle in snow in future studies, the FEM-MBD (finite element method – multi-body dynamic) coupling simulation model of articulated tracked vehicle running in snow was built. The vertical force distribution and vertical displacement distribution of snow under the load of tracked vehicle at rest and in running state were simulated. The simulation results show that when the tracked vehicle is in running state, the sinkage will be larger compared with that of tracked vehicle at rest in the snow. Field test on the performance of articulated tracked vehicle in snow was carried out. The deformation of snow in longitudinal direction and cross section of the vehicle was in good agreement with that of experiment which verifies the accuracy of the FEM-MBD coupling simulation model and the feasibility of using the FEM-MBD coupling method to study the dynamic behavior of tracked vehicle in snow.

The ability of the car to resist external disturbance during driving, i.e., robust stability is one of the most important performance requirements of the car, which seriously affects the safety of high-speed driving of the car. However, due to many factors affecting the vehicle handling stability, the evaluation methods and indexes used by different manufacturers and testers for handling stability tests are not consistent, making it difficult to form a recognized objective evaluation system with relying heavily on subjective evaluation, which has become the key issue hindering the development of vehicle handling stability performance. Based on $$H_{\infty }$$ H ∞ robust control theory, an objective quantitative evaluation index of vehicle robust stability based on $$H_{\infty }$$ H ∞ norm is proposed in this paper. The two-degree-of-freedom vehicle model is used as the research object, and the crosswind disturbance environment is used as the research scenario. The index is analyzed from four aspects: the position of the crosswind action point, the cornering stiffness of the front and rear tires, different conditions of road surface adhesion and the open-loop system and the closed-loop system. The results show that $$H_{\infty }$$ H ∞ norm is an objective index which is suitable for vehicle robust stability evaluation, and can provide the important theoretical guidance for vehicle structure design and vehicle stability controller design.

An analytical ring model conforming to the structural characteristics of non-pneumatic tires (NPTs) is established. Sensitivity analyses are conducted to determine effects of ring model parameters related to the spokes and the shear band on vertical deflection and contact patch length of the tire. The results indicate that the radial stiffness coefficient of spokes and the radial spring stiffness of shear band play the most important role in affecting the behavior of the NPTs. The equivalence of FEM and the ring model is found by investigating the correlation between design parameters of NPTs and crucial parameters of ring model, and based on this, a structural optimization method of NPTs is proposed to realize performance decoupling. An example of performance decoupling is given where a significant reduction of 5.31% in the maximum contact pressure is achieved while not changing the vertical stiffness of the NPT, thus breaking the design limits and providing guidance for the design of NPTs.

The objective of this study is to investigate the protection performance of active belt for occupants who out of position after the intervention of the pre-crash system. The CAE models under the AEB and the AES, are firstly established and the OOP occupants in different size is analyzed. Secondly, combined with the test and simulation methods, a comparison matrix of active and passive belts is established and the protection performance of occupants is analyzed. In addition, After AEB intervenes, the pitch angle was proportional to the braking deceleration, the ratio was directly proportional to the vehicle mass and the height of the center of mass, and inversely proportional to the square of stiffness and wheelbase. After the action of AEB and AES, the smaller occupants, the greater the out of position. The active belts had significant protection for the Hybrid III 5th Female, but not for the Hybrid III 50th and 95th Male.

In order to improve the accuracy of collision failure prediction of vehicle, a GISSMO-based method is proposed. Firstly, the key factors affecting structural failure are determined based on the failure prediction principles of the GISSMO model and an analysis of whole-vehicle failure factors. Secondly, according to the elastoplastic behaviour and the fracture characteristics of materials, the corresponding specimens are manufactured, and its mechanical behavior is analyzed. On this basis, the flow stress curves and GISSMO failure parameters for materials are given by analyzing the experimental data. Thirdly, the failure of the welding heat-affected zone(HAZ) is studied, and the failure parameters for the HAZ zone are obtained by comparing with experiments. Finally, the GISSMO failure model is verified and applied to the collision simulation of a vehicle. The rationality of the failure model is validated by comparing it with experimental results. The comparison results show that the GISSMO failure model can effectively characterize the failure behavior of the vehicle body structure and the welding heat affected zone, which can improve the accuracy of collision simulation and providing a new approach for the development of crashworthiness of vehicle.

Crash testing is a crucial method for evaluating vehicle’s passive safety performance. One important indicator for assessing the safety performance is the forward excursion of the occupant. In the “C-IASI 2020 Protocol” and its subsequent versions, the forward excursion of the driver-side dummy serves as a key indicator for evaluating the front seat occupant restraints and dummy kinematics. Measuring this indicator requires a set of “specialized apparatus”. The specialized apparatus is complex and costly, with undetermined precision in measurements. This article presents an algorithm founded upon the principles of inertial navigation technology, enabling precise computation of real-time motion states for a six-degree-of-freedom mobile object, a pioneering advancement that obviates the necessity for that specialized apparatus. By utilizing data collected from existing testing equipment, the algorithm performs a precise calculation of the spatial positioning of the dummy in relation to the vehicle body throughout the crash event. This calculation encompasses factors such as forward excursion and various other motion parameters. The algorithm’s accuracy is validated by test results and CAE analysis, demonstrating its high credibility and significant practical value.