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About this book

This book presents the proceedings of the second Vehicle Engineering and Vehicle Industry conference, reflecting the outcomes of theoretical and practical studies and outlining future development trends in a broad field of automotive research.

The conference’s main themes included design, manufacturing, economic and educational topics.

Table of Contents

Frontmatter

Conventional Powertrain

Frontmatter

Investigation of Diesel – n-Butanol Fuel Blend in the Function of Pre-injection Angle

The utilisation of renewable fuels and decreasing emission are important targets of the development and utilisation of compression-ignited and spark-ignited internal combustion engines. One solution can be the utilisation of different alcohols. With compression-ignited internal combustion engines, very often, ethanol and n-butanol are used for this purpose. The benefit of higher alcohols (C3–C4), like n-butanol, can be blended with diesel fuel without any surfactant or emulsifier. The aim of this study is to evaluate the effects of the blend containing 10 V/V% n-butanol, and the pre-injection angle on engine performance, combustion, and emission. It is a three–cylinder, direct-injection diesel engine used for the tests.While testing, it was observed that the fuel consumption of the blend was high compared to that of the D2 fuel. Butanol containing blend slightly showed peak cylinder pressure and heat release rate comparable to that of D2. Carbon monoxide (CO) unburned hydrocarbons (THC), and smoke emissions of the BU blend was lower in comparison to D2 fuel.

Attila Dobai, Ákos Bereczky

Optimal Manufacturing Technology Determination for the Main Parts of a Rotary Internal Combustion Engine

The paper deals with the cutting technology determination and the optimization possibility of finishing process of a new type rotary internal combustion engine. The construction and the working of the engine were introduced in previous publications. These publications presented the innovative idea resulted in the new internal combustion engine that has three rotary parts only. This paper continues the work aiming the realization of the first engine prototype with the investigation of the technological aspects of manufacturing. Among them the most important and interesting ones are the cutting and finishing of the two main parts of the engine: the rotor and the rotary chamber. The outer surface of the rotor is non-equal pitch helicoids, which can be manufactured more easily than the rotary chamber that has similarly changing, but internal helicoids. The paper analyses the possibility of manufacturing of these parts using free form milling with ball end milling cutters, and/or using NC controlled milling with disk-shaped cutters. Then, as an optimal finishing process, the grinding of these very complicated surfaces will be studied. The research work was aided by the Surface Constructor software application. As a conclusion, the selection between the possible milling technologies and the required milling tools and a proper grinding technology will be documented.

László Dudás

Review Article: Effect of Ethanol-Gasoline Fuel Blends on the Exhaust Emissions and Characteristics of SI Engines

The stricter worldwide emission legislation and growing demands for lower fuel consumption and anthropogenic CO, NOx and HC emissions require significant efforts to improve combustion efficiency of SI engines while satisfying the emission quality demands. In this review, different volume % of ethanol fuel combined with gasoline provide particularly promising and at the same time, a challenging approach. Ethanol is widely used as an alternative fuel or an effective additive of gasoline due to the advantage of its high-octane number and it self-sustaining concept, which can be supplied regardless of the fossil fuel for the contribution of its faster flame speed, leading to enhanced combustion initiation and stability and improved engine efficiency. As a result, numerous studies have been carried out to study its effects on engine performance and emission.Nearly all published engine experimental results showed a significant improvement in combustion characteristics and enhanced engine performance for the use of ethanol-gasoline blend as fuel. Moreover, carbon monoxide and oxides of nitrogen emissions were also significantly decreased. The objective of this paper is to provide latest fuel blend technique through literature review and their effects on the emission and performance of SI engines.

Barhm Mohamad, Gábor L. Szepesi, Betti Bollo

A Review on the Effect of Alternative Fuels on the Friction and Wear of Internal Combustion Engines

The climate policy of the EU specifies strict limits for harmful exhaust gases of passenger cars and commercial vehicles. Electric Mobility plays a significant role in reaching the fleet targets, but internal combustion engines (ICEs) will still be necessary in the next 30 years in medium to long distance transportation. Within the scope of this review article, research activities concerning engine performance, exhaust emissions, friction, wear and corrosion of components in relation to drop-in fuel alternatives, as well as the impact of such fuels on the degradation of the lubricant will be presented. Production pathways and properties of alternative fuels will be briefly introduced.

András Lajos Nagy, Jan Knaup, Ibolya Zsoldos

Alternative Powertrain

Frontmatter

Human-Electric Hybrid Drives in Medium-Sized Cities by Daily Traffic

There are several researches that examine the traffic of European cities. The congestion level of cities cannot be ignored neither in logistical planning. The congestion of vehicles has a number of harmful public health and economic impacts. Most of the researches examine only the metropolises and their environment, but under certain conditions in smaller towns, like Miskolc, congestions can be formed and the access times rise in critical traffic periods. At the University of Miskolc at the Institute of Machine and Product Design researches on the design and the use of human-electric hybrid vehicles started in 2011. In the last few years the University is getting overcrowded. Consequently the access times rise also among the University and the parts of the town. This is why we feel that the examination of such vehicles should be linked to the measurement of access times. The price of the human-electric hybrid vehicles, like all the electric vehicles, is relatively high in their category. It goes with that such vehicles are not prevalent. So we would like to perform an experimental series. In this series we would like to analyze the limits, advantages and disadvantages of the real use of human-electric hybrid vehicle. The first part of the series was an experiment in May 2017. In this research students and professors of the University of Miskolc were participate. Relevant part of the examination was to collect user experiences. In this research the measuring of the access time was just for curiosity. The main purpose was how to collect and how to use the measured parameters.

János Bihari, Ferenc Sarka

Development of an Electric Powered Light-Stilt-Tractor for the Application of Biological Plant Protection Products in Corn

Biological plant protection is growing steadily in conventional agriculture since it has some significant advantages compared to chemical products. These are the better biological compatibility and the avoidance of resistance development with comparable effectiveness at the same time. This paper presents a concept for a lightweight stilt-tractor with a serial hybrid electric drive train for application of biological plant protection products on the field. First of all, the requirements, resulting from the concrete application scenario, are described in order to define a suitable drive concept. This consists of two separate electric motors, which are connected to the respective drive wheel via two gear stages, consisting of a planetary gear and a chain drive. A 48 V battery serves as a buffer for covering power peaks and for short time purely electric drive. The continuous power demand of the vehicle is supplied by two power generator units, which take over the function of a range extender. Challenging for the construction are, in particular, the clear passage height of 1.80 m resulting from the application, the vehicle width that has to be adapted to the respective distance of the corn row and the position of the driver’s cabin above the rows of corn. In addition, the vehicle must be transported to its place of use on a standard car trailer. Due to these requirements, there is a need for a variable height and width adjustment while at the same time ensuring the stability of the vehicle.

Hannes Heidfeld, Ralf Hinzelmann, Martin Schünemann, Stephan Schmidt

Hybrid Drivetrain of a Self-driving Go-Kart

In the paper, we introduce the design and implementation of the drivetrain of a hybrid go-kart. The original go-kart was modified to fit the regulations of the “Go-Kart! Go-Bosch!” competition. The go-kart is equipped with numerous sensors that provide the necessary information about its close environment. The final goal of the three-year competition was to achieve autonomous driving on a go-kart based platform. One of the tasks was to modify the vehicles original drive train and implement the hybrid drive train of the team’s choice. The drivetrain had to include at least on electric motor and the original combustion engine of the go-kart. Since the original drive train only consisted of one rear axle which was connected directly to the clutch of the combustion engine of the vehicle, we had to implement a new design. We will discuss the design consideration and the difficulties, which occurred during the development process that led to the final construction.

Dávid Kiss, Attila Trohák

Modular Battery Cell Model for Thermal Management Modelling

Internal policies of the major car markets are urging for a cut in oil imports, leading to powertrain electrification. Due to their high weight-to-power ratio, Lithium-ion batteries, especially Lithium-Nickel-Manganese-Cobalt Oxide 21700 cylindrical cells, are rapidly becoming the most diffused electric powertrain energy storage devices. These devices need to be operated in a tight temperature range to prevent major power drops and also for safety reasons. It is therefore essential to provide an accurate but computationally inexpensive battery model. Current models are either too simplistic and not applicable for thermal management design purposes or too computationally expensive and impractical for heat exchange modelling purposes. This work was focused on a computationally convenient system-level-modelling-oriented battery cell model. Starting from a 1D model obtained from manufacturer’s data, experiments were carried out on real cells, a more sophisticated 3D model for cell characterization was implemented and then a lighter 1D model obtained from it was proposed. The outcome is a novel thermal model of batteries, with a reasonable computational cost, developed on the purpose of thermal management design. This represents an advancement in battery thermal management design, as no such model is currently available in literature.

Manlio Valerio Morganti, Stefano Longo, Marko Tirovic, Daniel J. Auger, Raja Mazuir Shah Bin Raja Ahsan

Vehicle Dynamics

Frontmatter

Analysis of Steering Geometry and Design of Steering Mechanisms for Four-Axle Vehicles

The purpose of this study is to understand the effects of steering geometry and to develop the proper steering mechanisms of a four-axle vehicle to improve the cornering behaviors. Firstly, based on kinematics and Newtonian mechanics, a 3-DOF steady-state cornering vehicle model, with considering Magic Formula of tire model and simplified suspension model, has been developed. The steady state cornering characteristics of a four-axle vehicle can be found by solving equations of motion. Secondly, implementing the suggested steering geometry, we can determine the optimized design parameters of the steering linkage by using a global search method. It is found that cornering behaviors of this new steering linkage can have better performance than the real four-axle vehicle we chose. Lastly, the effect of the fourth-axle is introduced and included into the investigation. The discussion on the steering geometry arrangements and its effect are presented. Based on the discussions and the design method developed in this work, the steering linkage of four-axle vehicle can be further developed to fit any case by achieving particular steering geometry.

Pai-An Chen, Yun-Jui Chung, Tien-Tung Chung, Tyng Liu

Durability Assessment: A Virtual Proving Ground Approach

The aim of the presented calculation is the assessment of the durability performance of a vehicle under realistic loading conditions. Widely used static calculations only provide a rough overview of the behavior as loads and boundary conditions are largely idealized and abstract, while dynamic effects are completely excluded. Significant improvement can be achieved by such transient simulations where the loads are more realistic and the body dynamics are included.However, the real life loading of a vehicle is largely unknown and thus, it is hard to analyze. In the physical world, accelerated proving ground tests provide a good approximation of service life according to several decades of practice. They have a serious limitation: they can be utilized only after a prototype is constructed. Meanwhile, they give a sound basis for simulations: virtual proving grounds can be constructed, where the vehicle concepts can be analyzed effectively in the earlier construction phases. The calculated results are directly related to those of the physical measurements, thus, they may be easily validated.Our company has successfully utilized this method for different application areas. In the present paper the results of case studies are showcased, where such multibody simulation is utilized to assess the durability performance of on-road and off-road vehicles based on the virtual proving ground approach. Besides the case studies, further possible development directions are identified and discussed. Also, the method is compared to durability assessments based on static load cases.

Gergely Erdős, László Takács

Characterization of the Vehicle Roll Movement with the Dynamic Chassis Simulator

Suspension Kinematics and Compliance (K&C) test rigs are one of the most important measuring facilities in the automobile industry, which support chassis engineers for chassis tuning and development as well as vehicle dynamics simulations. The Dynamic Chassis Simulator (DCS) at TU Dresden is a dynamic K&C test rig, appropriate for quasi-static and dynamic suspension K&C analyses. This paper presents the characterization method of the vehicle roll movement by applying relevant measurements on the DCS test rig. Important chassis design parameters in consideration with the roll motion are discussed and testing maneuvers on the DCS test rig to determine the design parameters are also explained. The validity of the characterization process of the roll movement has been proved with the field test data.

Chao Liu, Junyu Zhou, Axel Gerhard, Jan Kubenz, Günther Prokop

Modelling of Heat Generation in Vehicle Components Made of Rubber Caused by Finite Deformations

Generally, the most frequently used structural materials are metals which have high strength and stiffness. However, there are many cases, when other important properties come to the fore as well as high deformation by elastic behavior, high viscosity namely good damping effect. The metals do not have these above mentioned properties, but the rubber does. The rubber - thanks to its elastic behavior - is able to establish an elastic connection between hard and brittle structural elements, however, has high load carrying capacity. Vehicle components made of rubber usually exhibit large deformations. Cyclic finite deformations may induce increasing temperature in hyperelastic materials. This case - where changes in deformation and in temperature occur simultaneously - is called coupled thermomechanical problem. Both the mechanical and thermal processes have their own governing equations, that is why special techniques are needed for the computation. A special technique will be presented for solving coupled problems, this is operator split method. The goal of this paper is to show how to solve the coupled thermomechanical problem by the principle of virtual power and the principle of virtual temperature, and how to apply them together.

Veronika Szüle, Balázs Pere

Materials and Manufacturing

Frontmatter

Fatigue Performance of GMA-Brazed Non-load Carrying Joints Made of Ultra-High-Strength Steel

With the aim of maximizing energy efficiency, the use of low-alloyed ultra-high strength steels (UHSS) has greatly increased in vehicles and other transport applications in recent decades. Using UHSS, equivalent ultimate load capacity can be achieved with less material than when using conventional structural steels. Along with increased static load, structures commonly made of UHSS are often subjected to high cyclic load, and good fatigue strength is thus demanded. In this study, the fatigue strength was obtained for gas metal arc (GMA)-brazed non-load carrying joints made of S960 MC plates. CuMn13Al7 and CuAl8 were used as braze alloys. In addition, the work evaluated the potential of gas metal arc brazing (GMAB) as a post-weld improvement technique. A total of 21 different test specimens were manufactured and tested with constant amplitude fatigue tests with an applied stress ratio of R = 0.1. Notch effects of the braze joints were investigated numerically using finite element analysis (FEA). Depending on the braze alloy and joint configuration, mean nominal fatigue strengths of FATmean = 134–192 MPa were obtained, indicating that GMAB is a promising joining method for structures made of UHSS. The FEA results showed that for the studied materials and joints, stress concentration induced in the joint can decrease approximately by 20% when GMAB is applied instead of fusion welding.

Antti Ahola, Tuomas Skriko, Timo Björk

Milkrun Based In-plant Supply – An Automotive Approach

The material supply of workplaces in a manufacturing system can be realized in many ways. In the last few years, the milkrun-based in-plant supply is widely spread, especially in the field of the automotive industry. Milkrun supply makes it possible to feed manufacturing and assembly workstations keeping on the 9R rule. The lean approach is a framework for reducing costs and enhancing the quality of products and processes in automotive domain. The design and operation of milkrun based in-plant supply includes a wide range of optimization problems, like location, routing, scheduling, assignment or queuing problems. After a careful literature review, the authors describe the typical milkrun solutions of in-plant supply. The description of milkrun morphology makes it possible to define the most important aspects of milkrun supply solutions. Next, typical milkrun based supply processes are presented and their evaluation method is also described to analyze the efficiency of various solutions.

Tamás Bányai, Péter Telek, Christian Landschützer

Copper Rotor Technology for High Efficiency Motors

The asynchronous motor technology offers an easy solution for the e-traction. Two types of induction motor could be differentiated according to the used squirreled cage materiel, namely aluminium and copper. The copper rotor motor is being developed by many OEMs as a premium solution. The economical way to produce rotors for induction motors is the casting, independent of the applied squirrel cage material. High pressure die casting is the casting process attaining the highest productivity. The cast parts are near net shaped and often are they used unmachined in their as-cast condition.The actual industrial demands, due to the used very high motor rpm, require parts with improved physical properties, i.e. high tensile strength with good electrical conductivity in very narrow slots. Just only the pressure die casting technology is ready to fulfil the mentioned requirements.In the case of copper rotor, two manufacturing technologies are still in the race, namely the fabricated and the cast squirrel cage. Just only with the casting technology is possible to fill the newly developed very narrow rotor slots. Today it is possible to cast 1.3 mm thin slots with a stack length of 200 mm.At present, the Breuckmann group is developing in Hungary together with the University of Miskolc and Öntögepszerviz Kft. a casting system and a manufacturing cell for large-volume production of rotors with high process reliability. In the foreseeable future, the company will offer economically advantageous solutions for the industrial production of rotors for asynchronous motors.

András Bárdos, Csaba Walczer, Zoltán Kéri, Imre Selmeczi

Measurements of Vibration by Laser Doppler Method in the Course of Drilling

We measured the translational and torsional vibrations of the drill bit in the course of drilling process. The measurements were done by laser Doppler interferometric methods measuring the velocities on the basis of the Doppler effect. An LDV (Laser Doppler Vibrometer) device measured the translational vibrations, and then an LTV device measured the torsional vibrations (angular velocity changes) of the drill bit during drilling. Time series and frequency spectra were analysed in some periods of the metal cutting process. We identified translational vibration frequency groups around 100 Hz, above 1000 Hz and above 12 kHz. Meanwhile the typical torsional vibration frequencies were around 4400 Hz and 5600 Hz. We also observed the free oscillation of the drill at 480 Hz (in the pulling out phase), and some pseudo-oscillations at the higher harmonics of the rotational frequency.

Miklós Béres, Béla Paripás

Solidification Path of NemAlloy

The use of aluminium castings in automotive industries has dramatically increased in the last few decades due to the beneficial effects that arise by combining light weight and mechanical properties. Many of these castings have been used as parts of diesel engine. Diesel engines are subjected to high thermo-mechanical stresses, especially in the combustion chamber area of their cylinder heads. Due to the increasing demands needed for high power engines, weight reduction and elevating thermal and mechanical loads current casting produced using standard aluminium alloys (family of Al-Si and Al-Si-Cu alloys) are already reaching their limits, especially at elevated temperatures (>250 °C). New aluminium alloys able to fulfill these customers’ demands are therefore needed. Recently, the NemAlloy (AlCu7MnZr) has been developed by the Nemak Linz R&D-Team for cylinder head production for high performance engines. Beside good mechanical properties at elevated temperatures, the new alloy offers: hot tearing resistance, high thermal conductivity, low thermal expansion, high thermal shock resistance, corrosion resistance and good suitability to massive production. In the present paper the precipitation sequences that take place during solidification of this alloy have been identified applying Thermal analysis technique. Thermal analysis has been successfully applied in aluminium foundries for characterization of aluminium cast alloys. Characteristic solidification temperatures (TLIQ, TDCP, $$ {\text{T}}_{\text{Eu}}^{\text{AlSi}} $$,$$ {\text{T}}_{\text{Rig}} $$, $$ {\text{T}}_{\text{Eu}}^{\text{AlCu}} $$, TSOL…) and fraction solid distribution have been collected to support simulation as well as to provide necessary data for process development. The solidification path of the NemAlloy (AlCu7MnZr) has been compared with the precipitation sequence observed during solidification of the standard AlSi7MgCu alloy currently applied for cylinder head production.

Selina Dietz, Mile B. Djurdjevic, Ricardo Fernández Gutiérrez, Michael Rafetzeder

Logistics and Digitization

Quality of logistics activities plays an important role in corporate competitiveness. The appreciation of the role of logistics as a material and information flow is related to the rapid development of informatics and its technological background. The existence of intelligent devices, distributed intelligent hierarchical systems, a variety of management and control solutions, automatic identification systems, network communication systems, GPS tracking systems, cyber-physical systems, standardized data communications networks, web-based cloud solutions can be traced to the development of information technology. The use of digitization in logistics contributes even more to the better functioning solutions, the real-time management of large amounts of information using applications of Internet of Things, the use of simulation methods for making real-time decisions. These changes, of course, will significantly affect the functioning of the economy, the labour market and competitive situations as well.

Béla Illés, Attila K. Varga, László Czap

What Industry 4.0 Means for Just-In-Sequence Supply in Automotive Industry?

The available and future solutions for the digital transformation and use of exponential technologies indicate revolutionary changes in the whole supply chain of manufacturing and service processes. The vertical networking of smart manufacturing systems and the horizontal integration of value-making chains led to a new supply paradigm based on hyperconnected global logistics systems. The goal of the paper is to identify challenges of just-in-sequence supply in the automotive industry from the aspect of Industry 4.0 solutions. The authors introduce readers in both the Industry 4.0 paradigm as well as the just-in-sequence supply. Defining the conception of cyber physical logistics systems (CPLS) authors describe the I4.0 solutions based relations between just-in-sequence supply and Reference Architecture Model Industry 4.0 (RAMI 4.0). The main goal is to define challenges and impacts of Industry 4.0 paradigm on just-in-sequence supply.

János Juhász, Tamás Bányai

Preliminary Investigations for the Effect of Cutting Tool Edge Geometry in High-Feed Face Milling

The increasing of the cutting speed and/or the feed rate is often chosen to increase the efficiency of the material removal. Of course, there are limits to the selection of specific values in both cases, such as the rigidity of the machining system or the loadability and lifetime of the cutting edges. When increasing the feed rate in face milling, the conditions of chip removal are changing considerably, because at low feed values, the material forming effect of the side edge (i.e. the edge on the lateral surface of the tool) is the most critical and the chip deforms perpendicular to it, while increasing the feed gradually moves the primary part of the chip removal to the edge lying perpendicular to the tool axis. Therefore, both two edges have a distinct role in chip removal due to their position and geometry. As the two edges are located on one cutting insert, their geometry needs to be examined individually and collectively, and searching for the most suitable combination for effective chip removal is needed. Therefore, preliminary investigations were performed to aid in the constructional design of the tool as well as the proper design of the seat of the inserts. The simulations were carried out by the AdvantEdge Finite Element Method (FEM) software. The article shows the results of this analysis, which can be utilized to increase the efficiency of face milling, which is often used in the machining of automotive parts.

Bernhard Karpuschewski, János Kundrák, Csaba Felhő, Gyula Varga, István Sztankovics, Tamás Makkai, Dmytro Borysenko

Correlation Between Process Parameters and Cutting Forces in the Face Milling of Steel

In industrial practice, the production of parts must be conducted with acceptable surface quality, as well as increased dimensional accuracy and short machining time. For the creation of flat surfaces, face milling is a widely accepted method due to the possibility of achieving both high productivity and accuracy. In the present work, the correlation between process parameters and cutting forces is attempted for face milling, through a series of experiments. Experimental work is carried out based on Design of Experiments (DoE) methodology. The results are analyzed by statistical analysis tools and regression formulas correlating forces with process parameters are derived. Determination of optimum process parameters is also conducted with a view to increase process efficiency.

János Kundrák, Angelos P. Markopoulos, Tamás Makkai, Nikolaos E. Karkalos

Analysis of Machining Time and Material Removal Performance as Factors Influencing Efficiency and Profitability

In the automotive industry, the machining of hardened surfaces has become a serious topic in terms of its manufacturing and economic efficiency in recent decades. The reasons for this are the machining difficulty of hardened components and the need for machining that results in increased accuracy and surface quality. In addition to grinding as the conventional fine finishing procedure substituting procedures such as hard turning have appeared. They can be applied to reach surface quality and accuracy values equal to those of grinding. This paper analyzes different machining procedures (conventional bore grinding, hard turning and combined procedure) on hardened internal cylindrical surfaces, compared them in terms of time parameters of machining and the practical material removal rate as an efficiency parameter of material removal. While the practical parameter of material removal rate allows efficiency-based comparison of identical or different procedures (machining with abrasive or single-point tools), while the time parameters of machining (mainly the operation time) aim at direct comparability of costs of the procedures. The cost-related relationships of the procedures are also analyzed.

Janos Kundrak, Viktor Molnar, Istvan Deszpoth

Analysis of Supply Chain Efficiency in Blending Technologies

In an increasingly intense competition only companies recognizing the importance of cooperation among supply chain members can keep their market position in the long term. The aim of the study was to examine how to improve the competitiveness of automotive manufacturing companies through the network-based operation and optimum design of the procurement system in the case of blending technologies. During the analyzes, we will present a practical example of how to optimize the procurement system of network-based production companies using blending technology.

Gábor Nagy, Ágota Bányainé Tóth, Béla Illés, Elke Glistau

Significance of the Residual Stress Monitoring in the Automotive Industry

Determination of the residual stress is highly important because it has a strong effect on the lifetime of the component and it can cause deformation or failure during the manufacturing. Nowadays, the residual stress characterization became an everyday requirement in the automotive industry. Forasmuch as every producing process (casting, heat treating, different kinds of metal deformation processes and surface compressing methods etc.) influences the residual stress state, therefore it can be very complex and various within the components. If the effect of these processes are known, it is possible to reach such a stress state in the component which can enhance its lifetime and quality, and with an optimized process, the costs could be reduced.Several methods exist for measuring the residual stress. With this paper, our purpose is to introduce the non-destructive residual stress measuring by XRD, and show quantitative characterization and stress monitoring from the automotive and machine industry.

Mate Sepsi, Maria Salata, David Cseh, Valeria Mertinger, Marton Benke

Design and Analysis of Composite Oil Pan for Automotive Vehicle

The reduction of the carbon-dioxide emission of the vehicles is one of the main objectives in the research and development divisions of the automotive industry. The environmental pollution issues are still very actual that is why more regulations and standards are introduced to reduce the adverse effects on the environment. Thus, the new rules are adopted in the automotive manufacturing by the European Union and many car manufacturers are involved in developments aimed at the accomplishment of the significant weight reductions in vehicles.One of the solutions lies in the replacement of the material of the components. Modern composite materials can be competitive with metals; their properties can be even higher than for steels. The paper presents the process of substitution of the metal oil pan into the composite one. Design modification of the oil pan and overview of the molding injection simulations is discussed. The effects of cooling channel design on the warpage of the component are analyzed. Finite element simulation of the injection molded part is also performed where the microstructure of the composite is considered. Different levels of homogenization of anisotropic material properties are applied in simulations to demonstrate the importance of the accurate prediction of the fiber orientation. Finally, the results of the weight reduction arise from the metal replacement is presented.

Bernadett Spisák, Róbert Beleznai

Advanced Materials Handling Processes and Devices in the Automotive Industry

Automotive industry is one of the biggest sectors of economy, so any task related to it has also large significance. It is especially valid for the handling solutions used in production procedures of the automotive area. However there are many different handling processes applied suited for the individual production elements. In this paper authors give an overview about the materials handling solutions used in automotive production processes.As the application of different handling methods and equipment is principally based on the characteristics of the production processes, so authors also present the relations among the process and device parameters. Types and relations of the different parameters mean the base of the selection process of equipment for all of the handling procedures of the automotive industry and give ideas to develop new devices to fulfil the special requirement.

Péter Telek, Tamás Bányai

The Examination of the Effects of Strontium Content on the Properties of Cylinder Heads

During the experiments AlSi8Cu3 alloy was alloyed with strontium in different concentrations. The effect of strontium on the silicon in the eutectic structure was examined under operating conditions, in case of both higher (>100 ppm) amount of strontium content than usual in operating conditions and lower (~100 ppm) amount of strontium content, which is not used in practice.The extent of modification in the test bars casted during thermal analysis and in the final castings was determined with the help of cooling curves and by comparing them to images of reference standards. The reason for using these two methods was to determine the correlation between the levels of modifications determined by both the temperature of supercooling, which can be calculated from the cooling curves, and the structure evaluation methods. The mechanical properties of castings casted under the given cooling conditions were also examined. The fractures and microsections of the tensile test bars were examined with stereo microscope and scanning electron microscope.

Monika Tokár, György Fegyverneki, Viktória Boros, Valéria Mertinger

Conceptual Design of a Measurement- and Data Acquisition System

Within the framework of a project and organizational unit which formed in the near past, the authors were faced with a task for developing a universal test system. The system to be developed needs to have the ability to acquire data and measure different parameters which depend on the customers’ individual requirements. For this purpose, the test system has to be easily configurable and in terms of data acquisition it should follow the requirements of Industry 4.0. This article focuses on the tasks and requirements of the development, the possible devices and architectures for implementing the control system and the technical analysis methods for choosing the appropriate solution.

Attila Trohák, Zsófia Forgács

Vehicle Electronics

Frontmatter

Noise Reduction for Voice-Activated Car Commands

Speech communication is the most natural and quickest form of high-level communication for humans. It has long been an appealing goal to extend our abilities in this area to computers or other electronic devices, so that we could communicate with them with the same simplicity and speed which we communicate with other people. In addition, there are many circumstances when vocal communication has other advantages. For example, in vehicle environments the user can hands free control the navigation system or other functions of the vehicle while driving. Noise reduction is also important during calls or during conference talking inside buses. The article presents a spectral subtraction based noise reduction system with phase reconstruction for a two-microphone noise cancellation.

Laszlo Czap, Judit Maria Pinter

Autonomous Vehicles

Frontmatter

Creating OpenCRG Road Surface Model from Terrestrial Laser Scanning Data for Autonomous Vehicles

The OpenCRG road surface model as part of an open available data format is originally designed for simulation purposes, where the micro level information about the road surface is stored in this format. The paper introduces the whole open data format family (OpenDRIVE, OpenCRG and OpenSCENARIO) and then demonstrates that an efficient road surveying technology, namely the terrestrial laser scanning (TLS) is excellent data source to create realistic description about the road surface. The TLS captured point cloud stores very fine details about the surface, including height irregularities, potholes, cracks, manholes. Because the consortium being behind the developers contain car manufacturers (e.g. Daimler, BMW), mapping agencies (e.g. Here) and technology companies (e.g. Fraunhofer), the usage of the OpenCRG format is expected not only in laboratory circumstances, but later in real life applications. Autonomous vehicles have extreme requests for detailed information about the road and its neighborhood, and the developed open format seems to have excellent support to self-driving vehicle control.

Arpad Barsi, Vivien Poto, Viktor Tihanyi

Fuzzy Rule Interpolation Based Object Tracking and Navigation for Social Robot

The human-robot interaction will be more and more important in the close future. The behavior based robot control is simplified using fuzzy control. If the robot is doing a complex task, its behavior can be described with fuzzy rules. This kind of control method can be is easier implemented then the classical ones. Using fuzzy rule interpolation when the number of rules is high, the system can be described by the significant rules only.The paper presents a robot with ball playing task. The ball is detected using image processing methods. The images are processed using OpenCV library. The image processing function is implemented as a task of ROS node (Robot Operating System) on a Raspberry Pi computer placed on the robot. The mobile robot moves in holonomic way.In the field augmented reality markers are used for localization and navigation. The markers are detected on the same camera image as the ball. The markers positions are known by the robot. The robot computes its own position according to the detected markers. The navigation control is based on fuzzy rule interpolation, in this way the robot can avoid obstacles and approach the destination point.

Roland Bartók, József Vásárhelyi

Further Development of an AGV Control System

This paper deals with further development of an AGV (Automated Guided Vehicle) and its navigation method. The AGV can be found at the Logistic Institute at University of Miskolc. It was developed for a High-Tech Laboratory in 2011 by Gamma Digital Ltd. The system can perform delivering, picking and placing of materials.The AGV has a differential-drive with two caster wheels. A Mitsubishi 6-DoF industrial robot is mounted on it. A Wago PLC (Programmable Logic Controller) and a Linux-based PC handle the inputs and outputs. The PLC controls the lamps, switches and buttons. For safety reasons two SICK short range laser detectors were mounted on the front and rear side of the AGV. The navigation is performed by a SICK laser positioning sensor. The servomotors are controlled by Dugong servo drives, the signals for these drives are controlled by the PC. With the help of the PC both of the controllers are programmed to handle the navigation system and the safety sensors.The original software was corrected as regard adjusting voltage and to sophisticate, i.e., to smooth the start-stop system. A navigation method will be also described in the paper, which uses servomotors, laser pointers, microcontrollers, wireless modules and light sensors.

Ákos Cservenák

Accident Reconstruction Tools, with Special Attention to Autonomous Vehicles

Almost every vehicle in the world has a certain level of data recording device in the present. The parameters stored here will help you find the basic information about the vehicles. However, the capture unit can store the data itself up to an accident, which can be retrieved after saving. A number of tests are currently being carried out as to know exactly what these devices and what data can be extracted from them and how far they can be expanded. In many cases, the tests are done by colliding two cars from which the experts can analyze the recording of the usable devices after the break. These reveal the limitations of available locking units or the unused options available. This article describes all the tools that will allow you to explore the data recorded by the vehicles. These data can already be great significance for accident analysis. With the development of traffic and the emergence of autonomous vehicles, accidents can continue to happen with each other and with their environment. The tools help you if witnesses have not been present during the crash. This can happen similarly to the later levels of autonomy, when no driver is needed and no witness will be present during the collision. In the future, the data in our hands could make great progress in preventing accident, reducing environmental pollution, and even failing to reconstruct accidents.

Henrietta Lengyel, Viktor Tihanyi

Development of Robust H-Infinity Steering Control System for Autonomous Vehicles

Undoubtedly one of the most significant security systems for today’s autonomous ground vehicles is their steering system. A commonly used approach for control purposes in the automotive industry is the steering-by-wire concept. Despite its simplicity, this method is rather new and several concerns may arise regarding external loads arising from the tire-ground contact patch. This paper discusses the robust controller design of an electric steering-by-wire system taking into account multiple sources of uncertainty. In order to achieve robust performance, an H controller was selected for the task. This allows excellent disturbance rejection while requiring low computational needs. The design is verified using simulations and the final verification phase includes testing on the RECAR autonomous vehicle by utilizing rapid prototyping and hardware-in-the-loop tools.

György Max, Sándor Vass, Bálint Kiss

Trajectory Planning for Automated Vehicles – A Basic Approach

In the last century road transport has completely changed our life, nowadays mobility is a social need. Thanks to the recent revolution of science and technology, road vehicles have more automated features or systems. Initially the main motivation was to make driving easier or more comfortable, but world megatrends have oriented the development towards to lower fuel consumption, higher traffic safety and reduced environmental impact. To reach these future objectives it is necessary to increase the level of automation of road vehicles. Automated vehicles will overcome today’s cars in safety, efficiency, comfort, velocity and traffic density.Driving a road vehicle is a very complex controlling task, substituting the human driver with a computer is a real challenge also from the technical side. In connected and automated vehicles the control algorithm has several steps. An important step is, when the vehicle plans its own trajectory. The inputs of the trajectory planning are the purpose of the passengers and the environment of the vehicle (through the environmental perception system of the vehicle). The trajectory planning process has several parts for instance the geometry of the path-curve or the speed during the way. Furthermore the traffic situation also can determine many other parameters in the planning process.This paper presents a basic approach for trajectory design. The inputs will be target points on a 2D field which represents a smaller flat area with various roads. The 2D field are going to be a binary matrix, where the roads will be defined by ones, the obstacles will be defined by zeros. The aim is to make an algorithm which can find the shortest and a suitable way for vehicles between the start and the target point. The vehicle speed will be assumed slow enough to ignore the dynamical properties of the vehicle. The research is the first step to realise automated parking features in a self-drive car.

Ádám Nyerges, Viktor Tihanyi

Functional Description of Control Variables in Optimal Control and Application to Maneuver Planning for Autonomous Vehicles

This paper presents a method for reducing the number of optimization variables of a given optimal control problem by functional description of the problems control variables. Characteristic control sequences of elementary driving maneuvers are analyzed to derive requirements for generic functional modeling of the control sequence. Functions describing the whole control sequence at once are considered as well as piecewise representations. The optimal control problem is solved using these functional descriptions for both control inputs of a linearized single track model in two benchmark scenarios. The generated trajectories are compared to a reference solution for evaluation by residual cost of the optimization problem.

Michael Schmidt, Stephan Schmidt

A SUMO-Based Hardware-in-the-Loop V2X Simulation Framework for Testing and Rapid Prototyping of Cooperative Vehicular Applications

Vehicle-to-Anything (V2X) technologies aim at providing globally standardized communication tools to efficiently transmit information between all players of the transportation ecosystem. Based on such extensive data exchange between traffic objects V2X helps to create an advanced domain of transportation called Cooperative Intelligent Transportation Systems (C-ITS) where an ever-growing scale of cooperative vehicular applications/services facilitate enhanced safety and comfort on the road and lead towards fully automated transportation in the future. C-ITS relies on a complex architecture consisting of a cross-layer optimized sophisticated protocol stack, hybrid radio access solutions, computing algorithms, decision schemes, special interfaces, internet-of-things (IoT) integration, etc. Moreover, C-ITS and the support of cooperative use-cases demand high reliability, enhanced Quality of Service/Quality of Experience (QoS/QoE), and rock-solid hardware/software implementations working efficiently and securely even in the most complicated environments including extreme traffic circumstances or unpredictable actions. Therefore, deliberate system testing is a crucial and strategic process, especially when we are closing to the wide-scale deployment phase of real-life C-ITS solutions. Our proposed hardware-in-the-loop (HiL) V2X simulation framework was designed to offer a cost-efficient and simple toolset for testing and rapid prototyping of cooperative vehicular solutions by partially replacing costly, time-consuming and oftentimes dangerous field tests with an easy to install, tabletop laboratory test- and development suite.

Zsolt Szendrei, Norbert Varga, László Bokor

Noise and Vibration

Frontmatter

Verification of Rolling Element Bearing Defect Frequencies by Vibration Measurements on Bearings with Artificial Faults on the Outer/Inner Rings

Methods of vibration diagnostics have been widely used throughout many years for early detection of the failures of rolling element bearings. This method is based on the comparison of the results of vibration measurements (e.g. certain scalar values over a pre-determined frequency range, or time signals, or frequency spectra, etc.) against rules, and threshold values recommended by international standards. Depending on the results of the comparison the state of the bearing is considered as good, as acceptable or as not acceptable. This is a simple, but not always efficient method to detect faults, especially in early stage of bearing damage. This is the reason why other methods, including detailed vibration signature analysis, etc. have been developed and used all over the world. These methods of vibration analysis usually need the identification of the so called bearing defect frequencies, which can be calculated using mathematical formulas. The goal of our research was to verify the accuracy of calculation of these bearing defect frequencies, using artificial faults made on both the inner and outer rings of the bearing. For the tests 6 pieces of deep groove ball bearings (of type 6205), mounted in a test rig, driven by a variable speed electromotor rig have been used. Vibration signals have been recorded in three directions (axial, horizontal, and vertical), at three different rotational speeds (500 rpm, 1000 rpm and 1500 rpm), using Envelope Acceleration, HFD (High Frequency Detection) and SEE (Spectral Emitted Energy) methods, and 17 different measurement setups. Altogether 918 measurements have been carried out. The results were evaluated on time signal records, vibration spectra, including waterfall diagrams and Palograms. As a conclusion, it was found that the accuracy of bearing defect frequencies is acceptable, and the best method for an early warning of potential bearing failure is the so called Envelope Acceleration signal.

József Zoltán Szabó, Ferenc Dömötör

Active and Passive Safety

Frontmatter

Vehicular Can Traffic Based Microtracking for Accident Reconstruction

Accident reconstruction is the process of reliably discovering what has happened before a serious event. We show how the most widely used intra vehicular network (namely the Controller Area Network, CAN) can be used in this process. We show how the actual velocity and steering wheel position transmitted on the CAN network can be used to reconstruct the trajectory of a vehicle. This trajectory is an essential input in the reconstruction process. In this paper, we show how the CAN traffic of an actual vehicle can be used to reconstruct the trajectory of the vehicle, and we evaluate our approach in several real life experiments including normal and pre-accident situations.

András Gazdag, Tamás Holczer, Levente Buttyán, Zsolt Szalay

Investigation of Pressure Rise in Automotive Airbags

Safety is a widely spread topic in engineering, from specific producing processes to everyday life. Innovation of passenger cars belongs to the frontline of industrial sector. Higher and higher performance motors, more streamlined vehicle dynamics, more reliable autonomous vehicles, and minor noise and vibration are the most expected developments what customers prefer. However, it is not allowed to forget automotive safety, which effectiveness prevents fatalities to drivers and passengers.A very important part of this safety system are the airbags. Frontal airbags aim at preventing serious injuries from impacts of the driver’s or passenger’s head or upper body against the steering wheel or other parts of the vehicle. Worldwide almost every vehicle produced with frontal or front-seat passenger airbags. Their improvement and investigation of operation is a main role of production. Pressure rise and gas temperature in bladders are significant information related to their operating mechanism.Many investigations can be found in literature which describe the occurring processes during the explosion. Most of them are computational or experimental ones, and others sets up mathematical models. This paper presents options of modelling pressure rise in automotive airbags and inflators.

Viktória Mikáczó, Zoltán Siménfalvi, Gábor L. Szepesi

Comparison of Data Required for Accident Reconstruction Based on Crash Test

Accident analysis and reconstruction classically based on tracks recorded during the scene investigations of an accident. In a case ideal for the post reconstruction of the accident, these traces can greatly help reconstruction of the accident process. However, in most cases, it is not possible to record all necessary traces, so it is not possible to use these data later. There are tools from the 1950s - with continuously evolving features, - that could partially respond this problem, for example by continuous monitoring certain vehicle dynamics parameters, and by recording these parameters at a time of an accident occurring, useful information can be gained about the vehicle’s state of motion. The data provided by accident data recorders can thus provide useful information on accidents involving traditional vehicles, but their significance is growing especially with the spread of highly automated and autonomous vehicles, where the control of the vehicle can, in certain circumstances, be transferred to the vehicle. In this article we will present the data that can be used for modern accident analysis, then we will investigate accident data recorded during crash tests, which were collected from the vehicles own control units with EDR functions, and by the post-fitted event data recorders during collision attempts. On the basis of our experiences and conclusions, we will make suggestions on the range of optimal data from the point of view of accident analysis, on the recording of these data, paying particular attention to autonomous vehicle specific solutions.

Krisztian Pinter, Zsolt Szalay

Presentation of Modern Accident Reconstruction Procedures - Case Study

Nowadays, the reconstruction of traffic accidents utilizing current vehicle technology presents new challenges for professional accident analysis. The downloading and reading of data stored in vehicles and the professional interpretation of these data is becoming important for full interpretation of the accident reconstruction. But this data cannot be interpreted without the use of separate mathematical analysis and comparison to the physical scene data for the analysis of traffic accidents.In this paper, the process is discussed of an accident resulted by a Toyota Yaris passenger car’s stability loss of control that resulted in a traffic accident.During the analysis, we will use data from the electronic EDR (Event Data Recorder) placed in the vehicle, as well as data recorded by in the auxiliary equipment (on-board camera).In determining the most likely accident process, account should be taken of the data obtained from other accident related devices as well as the GIS data for the environment. The paper details how data from different sources can be evaluated, how conflicting data can be reconciled and, how to resolve contradictions.

Gábor Vida, Istvan Bodollo

Sustainability

Frontmatter

Sensitivity Investigation of Failure Mode and Effect Analysis

The Failure Mode and Effect Analysis (FMEA) has spread in wide range of modern automotive engineering. This means, in our days this method is present in manufacturing and development of vehicle systems. Although, the earliest focus was on the mechanical components, today electronic elements and software components must be included, due to the increase of system complexity. The change mentioned above underlines the fact that complexity and size of vehicle systems results in a reduced transparency and meaning of similar Risk Priority Numbers (RPN). Therefore an obvious and simple overview should support analysts in highlighting the most critical points of an entire system. Our proposed method should not require additional and long term work packages, but should rely on raw values of FMEA. This method supports the identification of sensitive parts within an entire system, pointing out the meaning of critical content behind.

László Pokorádi, Gábor Ványi

Assembly System Planning in Automotive Industry with Use of Discrete Event Simulation

As automotive assembly systems become more complex every year, use of computer aided technology in planning stage is common. Every change in assembly system or assembly line must be validated by software engineering department so the transition in changes are smooth and without unexpected problems. Assembly systems especially in automotive industry must be easy to adjust for new production. Companies in automotive industry, especially manufacturers of final cars have production lines for several versions of one car or even for different car models. This means that production systems are complex and must be balanced for work with different set ups. Time and work flow are essential things in production lines in automotive industry. That is the reason for software solutions like Tecnomatix. Implementation of new assembly parameters are calculated by software. Looking for bottlenecks or errors in assembly processes is easier in well-made virtual models of production lines and it also faster solution. In this article will be mentioned software solutions for this kind of processes. Basic work of software will be demonstrated in example made in Tecnomatix Plant Simulate and Tecnomatix Process Simulate from company SIEMENS. Examples made in these software packages will be aimed on automotive assembly respectively production lines. Also, simulation of production robotic workplaces will be mentioned in example with use of Tecnomatix Process Simulate. As welding robotic stations in automotive production systems are essentials of whole production. Robotic stations are high investment workplaces, so it is only understanding that simulation of such robotic workplaces is needed. Use of discrete simulation software for production simulation purposes is bigger every year and it will continue in future as well. Future of assembly planning will be discussed towards the end of article.

Štefan Václav, Peter Košťál, Šimon Lecký, Dávid Michal, Branislav Bako

Education

Frontmatter

Survey About the PSOC5 LABBOOK

This paper falls within the context of practical works for embedded systems subject organised for students of the University of Miskolc. The LABBOOK collects lab materials and two mini-projects using Cypress PSoC 5LP (CY8CKIT-050) Development Kit and some discrete components. The kit is based on CY8C5868AXI-LP035 chip that includes ARM Cortex™ M3 microcontroller in addition to digital/analog reconfigurable area. Starting from a getting started guide and blinking LED test to familiarise with PSoC development tools, this training course material presents to students a set of labs with growing difficulty until they confront more complex designs and get prepared to face the mini-projects proposed in the end of the LABBOOK.

Ahmed Bouzid, József Vásárhelyi

10 Years of Pneumobile Competition at the University of Miskolc

The 10th International Pneumobile Competition was held in May 2017 by Aventics Company. The Pneumobile Competition is a special project based learning for engineering students. The object is the design and construction of a “pneumatic vehicle” – PNEUMOBILE –which is driven by compressed air. Vehicle should be designed in accordance with the rules included in General vehicle specification. Pneumatic elements and PLC for building the vehicle will be provided by Aventics Hungary Kft. for the teams. The University of Miskolc (UM) has had a great tradition in this fantastic race because in the first competition three vehicles were built. Since then altogether 15 vehicles have been built and more than 50 students from our University have been involved in this work. In this article, the history of the participation of UM at the Pneumobile Competitions and the typical difficulties which can be show up during the planning and building phases have been summarized.

László Kelemen

Design of Vehicle Structures and Surface

Frontmatter

Characterization of Surface Roughness for Growth Models

The technique of growth surfaces under Molecular Beam Epitaxy (MBE) has received considerable attention for a wide range of technological and industrial applications. This approach provides a unique capability to grow crystalline thin films with precise control of thickness, composition and morphology. This enables scientists to build nanostructures as pyramidal objects or mounds. The evolution of the surface morphology during MBE growth results from a competition between the molecular flux and the relaxation of the surface profile through surface diffusion. The richness of patterns forming during MBE is determined solely by processes which occur locally at the surface.Our aim is to describe the coarsening process by mathematical models. Analytical results on the surface roughness are provided. Numerical simulations are presented to show the roughening of the surface pattern and the evolution of the surface morphology in time in one-dimension.

Gabriella Bognár

Airbox Design, Analysis and Improvement for a High Performance Road Racing Sidecar

It has been well documented that the performance of an engine can be adjusted through altering the design of the air intake system. A full four stroke Otto cycle is an unsteady cycle with the continuous charging and discharging of the intake system. The characteristics of airflow within the inlet system can be described as a function of frequency. This frequency can be altered to aid in increasing the volumetric efficiency (VE) of the engine at a desired point/s. This paper reviews the air intake system used by Dave Molyneux Racing (DMR) for their sidecar racing in the Isle of Man Tourist Trophy (TT). An iterative design process found that the airbox design needed the intake pipe to be as straight as possible and facing the free stream flow. Turning vanes were used in the intake pipe and airbox to aid in ensuring uniform pressure across the four bell mouths of the intake system.

Lewis Parry, László Könözsy, Clive Temple

Numerical and Experimental Study of Finned Tube Heat Transfer Characteristics

The automotive radiators are one of the most important ancillary equipment of the vehicle engines. This appliance cooling the engines with circulation of cooling fluid between the engine block and the radiator. The mass of the ancillary equipment is an important viewpoint, so every saved kilogram means performance growth and can help to achieve a cost-effective operation. Even though under-sizing of this thermal energy system cause life span decreasing.The objective of the present numerical study is to investigate the thermal characteristics of various plate fins with various fin pitches. Computational fluid dynamics models of fin and tube heat exchanger with different fin patterns are developed to investigate the fin pattern behavior on the heat transfer. To validate these numerical results, measures have been made. To modeling an automotive radiator, a personal computer water cooling kit is used. The temperatures of the cooling fluid and the volume flow of the air and the cooling fluid can be measured. In case of identical values, with the computational fluid dynamics method the effect of the fin patterns can be investigated. This study demonstrates, contextualizes and communicates the advantages of structural and material efficient fin design in conjunction with energy efficiency from large-scale application.

Máté Petrik, Gábor L. Szepesi, Tibor Varga

Quality Control and Refinement of Car-Body Surfaces

The quality of the car-body surfaces is evaluated in the design phase. For that purpose, sensitive methods were developed; these are mainly the evaluation of the shape and distribution of reflection lines or highlight lines. In the paper, we propose a method to semi-automatically evaluate and improve the quality of the highlight line structures. Following the selection of the defective highlight line segments, the correction is carried out in two steps. First, sequences of evaluation points are computed to quantify the error in terms of distance and angle functions. Next, the corrected highlight points are calculated, and based on these points the corrected highlight line segments are constructed. The correspondence between the shape of the highlight lines and the surface parameters is highly complicated and strongly nonlinear. In the paper, a genetic process is proposed for the computation of the parameters of the surfaces, that corresponds to the corrected highlight line structure. Application of the method is demonstrated by correction of the highlight line structure and the shape of several car-body surfaces.

Gábor Renner, György Gyurecz

Optimization

Frontmatter

Optimization of Springs Applied in Vehicle Suspension Structure

In this paper the grapho-analytical optimization of compressed helical cylindrical springs with two design variables and the optimization by RVA algorithm of laminated springs with four design variables are shown. For the helical spring the 3D model of the assembly of the spring into a car suspension system is built and the model is analysed in a finite element program system and a demonstration example is shown for graphical and analytical optimization of the spring. Regarding the RVA optimization algorithm, the iteration history curve is analysed, finding the effects of the parameters in the equations of the curves. It is possible to continue this analysis with the study of the derivatives or integrals of these saturation type curves, the results of which could give very interesting and useful points of view for the “numerical experiments” process to set the best values of the parameters influencing the algorithm thinking. On the basis of these results a new system for comparison and qualification can be developed, which can be used in other fields too (comparison of student groups, competitions, applicants for several funds, grants or jobs, etc.).

Ferenc János Szabó

Design and Optimization of a Bus Steering Linkage by Using Response Surface Methodology

Computer-aided design phases of the steering linkage of a passenger bus are presented. In the first part of the study, proper joint positions of the mechanism which satisfy the kinematic requirements such as, acceptable toe deviation and steering error ranges, were determined. For this purpose, a rigid multibody model of the mechanism was built by taking the physical design restrictions of the front axle into account. Subsequently, a response surface methodology (RSM)-based kinematic optimization study was carried out by using Adams®/Insight software. In order to determine the service forces acting on the structural elements of the linkage, a full multibody dynamics (MBD) model of the bus was also composed. By using this model, standard lane change maneuver was performed. Furthermore, the theoretical steering torque at the tire contact patch, necessary to steer the front wheels of the bus at zero speed, was calculated. Force analysis of the linkage was also performed for this condition. In the second part, mechanical design of the full steering mechanism was carried out for critical design load. Finite element analysis (FEA) was implemented to predict the stress concentration regions of the primary design model for the selected load cases such as zero speed steering, lane change and braking. Design optimization of the linkage components were also carried out by using ANSYS® Workbench™ software. Hence, optimal shapes of the structural elements, which satisfy the design targets such as minimum equivalent stress and maximum stiffness, were determined. According to the results obtained from this study, the steering linkage satisfies the safety condition for critical load cases.

Mehmet Murat Topaç, Merve Karaca, Uğur Deryal, Mert Atak

Research and Application of Industrial Robot Manipulators in Vehicle and Automotive Engineering, a Survey

The tendency of the manufacturers to lower costs, accurate work, and fast production rates force them to look for extraordinary ways like using robots instead of humans in an industry which meets their requirements. One of the most important operations in vehicle industry is welding. This operation requires proficient workers and it is time consuming as well as fallible. The application of robots can increase the productivity and the quality in this area. Other fields like painting, material handling also can have benefit from the application of robots. This work is going to review the usage of robot manipulators and their different applications in the automotive and vehicle industry and the relationship between the applications and the optimized robot manipulators also a review was made about robots’ statistics worldwide.

Hazim Nasir Ghafil, Károly Jármai

Cost Calculation of Thin-Walled Structures Using Different Manufacturing Techniques

The calculation of costs is important to improve competitiveness of thin-walled elements. In the optimization process the design, fabrication and economy are combined. Several optimization techniques are available. The different manufacturing technologies are the joining (welding, gluing, riveting), cutting, forming, cleaning, painting etc. Within the given technology groups there are several different technologies available like at welding: shielded arc welding, gas metal arc welding, submerged arc welding, laser welding, plasma welding, etc. Also, at the cutting group: propane gas, mixed gas, laser cutting, plasma cutting, waterjet cutting, etc. The cost calculation includes these using for thin plates and sections.

Károly Jármai

Elastic Plastic Analysis of Elliptical Plates

The elastic response of elliptical plates to distributed transverse loading is considered. Resorting to the Haar’s wavelets a numerical algorithm for determination of stress and strain components is developed. The material of the plates is assumed to be an ideal elastic plastic material satisfying corresponding yield condition and associated flow law. Particular problems are solved in the cases of stepped plates and Hill’s and Tsai-Wu materials. Numerical results are presented for one- and two-stepped plates.

Jaan Lellep, Boriss Vlassov

ε-Optimum Reliability-Based Cost Design of Longitudinally Stiffened Welded Steel Plates

The aim of this work is the reliability-based optimization of a stiffened plate subjected to in-plane or combined in-plane and transverse loading. The design variables are the thickness of the base plate, the number of stiffeners and their thickness. The constraints deal with the overall plate buckling, the stiffener failure and the distortion of the plate due to welding. The cost function includes the cost of material, assembly and welding. Randomness is considered both in loading and material properties. A level II reliability method (FORM) is employed. The overall structural reliability is obtained by using Ditlevsen method of conditional bounding. The branch and bound strategy is employed to enumerate ε-optimum costs, which are solutions within a specified tolerance of the optimum.

Luis M. C. Simões, Károly Jármai, Zoltán Virág

Supply Chain Optimization in Automotive Industry: A Comparative Analysis of Evolutionary and Swarming Heuristics

In every manufacturing, assembly or forwarder systems there are problems determined by a wide range and number of parameters. The increased number of variables and parameters leads to the increased number of required computational time for the exact solution. In this situation, heuristic and metaheuristic algorithms are useful tools to find the optimal or near optimal solutions of the problem. These methods are often combined parallel or sequencial and choosing the best algorithm is a quite complex question. There are two very important factors in computing: computational time and accuracy. In addition, there are secondary aspects, such as robustness or alternative solutions. Within the scope of this paper authors compare one of the best-known algorithms; the genetic algorithm with a relatively new swarming algorithm; the black hole algorithm. The efficiency of both algorithms will be demonstrated with a supply chain optimization problem in automotive industry, where more design tasks of logistic processes will be solved, like location and assignment of resources.

Péter Veres, Béla Illés, Christian Landschützer

Welding

Frontmatter

Resistance Spot Welding of 7075 Aluminium Alloy

New generations of high strength aluminium alloys are widely used in automotive industry. 7075 (AlZn5.5MgCu) is an aluminium alloy with zinc as the primary alloying element (according to EN 485-2 standard). The 7075 has outstanding strength properties, but the elongation is limited between 5 and 11%. This means an obstacle when this alloy is aimed to use in car body elements. The goal of the present research work is to analyse the weldability of this alloy through resistance spot welding (RSW) tests. Experiments are performed on 1 mm thick 7075 sheets in T6 condition with different surface pre-treatment methods and the weld lobe was determined for constant electrode force. A Tecna 8007 RSW equipment with a TE 550 control unit was applied, which has been recently developed with a tool for the application of post pressing force. The spot welded joints were examined by macro testing, tensile shear and hardness tests. The properties of RSW joint from 7075 were compared with the 6082 alloy.

Ádám Dobosy, Marcell Gáspár, Imre Török

The Effect of Solution Annealing and Ageing During the RSW of 6082 Aluminium Alloy

In the automotive industry there is a growing tendency for the application of high strength aluminium alloys. In spite of their significant role in weight reduction there are still obstacles for their wider use due to their limited formability and weldability. Hot forming and in-die quenching (HFQ) process was recently developed for the forming of car body sheets. During the HFQ technology the sheet metal forming should be performed in a solution annealed condition. In the solution annealed condition the aluminium alloys have lower strength and better formability properties. The forming process is followed by a precipitation hardening which is generally connected with the painting of body parts (bake hardening). Besides the formability the implementation of HFQ has an effect on the weldability properties, too. HFQ must have an effect on the resistance spot welding (RSW) of aluminium sheets since the weld nuggets are produced after the HFQ, in the assembly part of the production chain, when the aluminium alloy is in a solution annealed and formed condition. The final properties of the welded joints are determined by the precipitation hardening which is the final step of the whole production process. The present research work aims to investigate the effect of the HFQ process on the weldability of AA6082-T6 aluminium alloy. The properties of the RSW joints are examined in different conditions (T6 delivery condition, solution annealed, precipitation aged). The materials tests include conventional macro testing, hardness tests and tensile-shear tests extended with EDS (Energy Dispersive Spectroscopy) and EBSD (Electron Backscatter Diffraction) tests in order to characterize the distribution of alloying elements and to analyze the grain structure.

Marcell Gáspár, Henri Tervo, Antti Kaijalainen, Ádám Dobosy, Imre Török

Dissimilar Resistance Spot Welding of Ferrite-Martensite Dual Phase Steel/Low Carbon Steel: Phase Transformations and Mechanical Properties

Metallurgical characterization, failure mode transition and mechanical properties in dissimilar resistance spot welds of dual phase steel (DP600) and low carbon steel (MSZ EN 10130) are analyzed. It was found that the fusion zone microstructure contains a complex microstructure of retained austenite, martensite, and bainite. The peak hardness in the heat affected zone of advance high-strength steel was greater than fusion zone hardness due to the higher hardenability of advance high-strength steel compared to fusion zone. Dissimilar DP600/EN 10130 spot welds show the highest trend to fail in pullout failure mode with good mechanical properties. Effects of weld microstructure and fusion zone size on mechanical properties dissimilar DP600/EN 10130 spot welds are analysed.

Hassanen Jaber, Tunde Kovacs

MIG Welding and MIG Brazing of Different Austenitic Stainless Steel Grades

Weldability aspects of different Cr-Mn alloyed high strength austenitic steel grades were investigated in our present work and compared to conventional Cr-Ni alloyed grades. In our experiments two Cr-Mn alloyed high strength (+N alloying) austenitic steel grades (1.4371 and 1.4376) and as comparison; Cr-Ni alloyed high strength (1.4318) and normal strength (1.4301) austenitic steel grades were used. Similar and dissimilar joints were made with metal inert gas (MIG) welding and MIG brazing.The produced butt joints were evaluated according to their tensile- hardness- and microstructural properties. The different steel grades showed quite different behavior regarding the mechanical and microstructural properties.The MIG brazed specimen showed higher weld metal hardness than the welded ones, the hardness values decreased with decreasing Mn-content in the base metals. In case of MIG welding also the tensile strengths and the fracture elongation of the joints decreased with decreasing Mn-content.

Eszter Kalácska, Balázs Varbai, Kornél Májlinger

Investigation of the Ultrasound Welded Aluminium Joint Microstructure

The ultrasound welding is a special welding process. Usually use in case of cold rolled sheets. The car industry electrical parts cases made by ultrasound welding. Requirement in case of these parts the electrical connectivity and this shield needs to be a Faraday cage. This technology use ultrasound and pressure to establish a welded joint. During the joining it can detect some heat from the high frequency sound affected friction. This is a very complex process. This technology combines the affects what it can detect during the friction welding, the diffusion welding and the cold pressure welding. This heat isn’t enough to melt the materials, but it can affect recrystallization of the used cold rolled metal [1, 2]. The grain size and geometry depend on the used parameters and the level of the used sheet shaping estate. The goal of this work to find the relationship between the welded joint grain size and the used parameters of the ultrasound welding.

Tünde Kovács

Fatigue Crack Propagation Limit Curves for High Strength Steels and Their Welded Joints Based on Two-Stage Relationship

The objective of the paper is to present the newest results of our complex research work. In order to determine and compare the fatigue resistance, fatigue crack growth tests were performed on S690QL and S960QL quenched and tempered (Q+T) type high strength steels. 15 mm thick base materials (SSAB Weldox 700E and Weldox 960E) were used for our investigations. Welded joints were made from these base materials, using gas metal arc welding (GMAW) with matching (M) filler metals (Thyssen UNION X85 and UNION X96). In the paper, the performance of the welding experiments will be presented; together with the results of the fatigue crack growth (FCG) examinations executed on the base materials (BM) and their welded joints (WJ). Statistical aspects were applied both for presenting the possible crack locations in the base materials and the welded joints, as well as for processing the measured data. Furthermore, the results will be compared with each other, and fatigue crack propagation limit curves will be derived using two-stage relationship.

János Lukács

Mismatch Effect Influence on the HCF Resistance of High Strength Steels and Their GMA Welded Joints

The objective of this article is to present the newest results of our complex research work related to the high cycle fatigue (HCF) resistance of advanced high strength steels. HCF tests were performed on two strength categories (690 and 960 MPa) including quenched and tempered and thermo-mechanical types. During the HCF tests base materials and their gas metal arc welded joints were investigated at different mismatch conditions (matching, undermatching, overmatching). Measured and analyzed data about base materials and welded joints were compared and discussed. Statistical approach was applied during the preparation and the evaluation of the investigations, which increased their reliability. The parameters of the HCF design curves were calculated based on the Japanese method (JSME S 002-1981) which uses 14 specimens. During the evaluation the results were compared with each other and with literary data. According to the presented examinations the HCF resistance of the base materials is more advantageous than the welded joints. Both the steel production process and the mismatch effect have an influence on the HCF resistance, depending on the strength category and the steel type. The thermo-mechanically treated steel indicated better fatigue resistance than the quenched and tempered one of the same category.

Haidar Faisal Helal Mobark, Ádám Dobosy, János Lukács

Arc Welding of Zinc Coated High Strength Steels

In the automotive industry advanced high strength steels (for example: DP, CP, TRIP, TWIP) are used for different applications on the body or on the chassis. The most commonly used jointing technologies in the automotive production are the arc welding processes. By using conventional welding technologies problems can occur. Using conventional welding on coated (galvanized) plates usually damages the coating. The consequence of this damage will be corrosion and extra maintenance costs. To solve this problem low heat-input process variants can be applied. They can be e.g. Cold-Arc, SpeedARC, forceArc, CMT, Cold Weld, microMIG, microMIG-cc, and other advanced welding processes. These are controlled short circuit material transition processes. We investigated the Cold Weld, microMIG and microMIG-cc processes when welding zinc coated high strength steel plates. The microMIG-cc and Cold Weld processes were found well applicable for the coated plates. This paper describes those welding possibilities of these plates which will not be damaged the coating on the other side of the weld.

Tibor Pogonyi, Béla Palotás, Levente Bakos

Mechanical Properties in the Physically Simulated Heat-Affected Zones of 500 MPa Offshore Steel for Arctic Conditions

Offshore steels for the arctic conditions have an increasing demand due to the opening of new oil fields in the Arctic Ocean. However, the requirements for these steels are extremely demanding, as they need to maintain the desired properties in harsh arctic conditions. Additionally, these requirements need to be achieved also in heat-affected zones caused by the welding. In this study the heat-affected zones were created using the physical simulation, so that the zones would be wide enough for reliable mechanical testing. Continuous cast 500 MPa offshore steel was hot rolled in the laboratory hot rolling mill to find out the mechanical properties of the base metal. The physically simulated heat-affected zones were studied using Gleeble 3800. Two different cooling times from 800°C to 500°C (t8/5) were used in order to simulate two different welding methods with different heat inputs. Microstructure of both base materials and simulated heat-affected zones were studied using scanning electron microscope and laser scanning confocal microscope. Charpy V-notch impact toughness and hardness profiles were determined of both base material and simulated heat-affected zones.The base metal microstructure was ferritic with some lath-like bainitic features. Minor changes were noted in the microstructure of physically simulated inter-critical heat-affected zone (ICHAZ), while in physically simulated coarse grained heat-affected zone (CGHAZ) the prior austenite grains had coarsened and the transformation microstructure consisted of lath-like features of bainite and in case of a shorter t8/5 of 6 s, even martensite. It was found out that the critical location regarding the impact toughness in arctic temperatures was found out to be CGHAZ, while the impact toughness of ICHAZ did not differ remarkably from that of the base material. The CGHAZ impact toughness was weaker with t8/5 = 30 s than with t8/5 = 6 s indicating that lower heat input welding methods are more beneficial for this material.

Henri Tervo, Juho Mourujärvi, Antti Kaijalainen, Jukka Kömi

Thermoelectric Power Measurements on Duplex Stainless Steel Weldments

In our research bead-on-plate autogenous TIG welds were prepared on 2 mm thick UNS S32205 (EN 1.4462) duplex stainless steel sheets using different shielding gases: argon, and argon+nitrogen shielding with +2 vol. % N2, +5 vol. % N2 and +10 vol. % N2 nitrogen content beside argon. The welds were reheated in argon atmosphere up to 1250 °C peak temperature, using Gleeble® 1500 thermomechanical simulator. Both in the as-welded and reheated state the austenite fraction, total nitrogen content and thermoelectric power (TEP) values were measured. Correlation was found between the austenite content in the weld metal, the total nitrogen content in the wed metal and the TEP value as a function of the used shielding gases and the subsequent reheating thermal cycle. We also attempted to differentiate between the total dissolved nitrogen and interstitial atomic nitrogen. This work is a part of an extended project in order to understand the sometimes controversial effects of nitrogen on duplex stainless steel welding.

Balázs Varbai, Kornél Májlinger

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