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15th International Munich Chassis Symposium 2024

Volume 2: tire.tech and break.tech

herausgegeben von: Peter E. Pfeffer

Verlag: Springer Berlin Heidelberg

Buchreihe : Proceedings

Enthalten in: Springer Professional "Wirtschaft+Technik" , Springer Professional "Technik"

Inhaltsverzeichnis

Über dieses Buch

Innovation and sustainability are the key factors in the development of a future-proof chassis. The symposium exceeded expectations and brought together leading experts in chassis technology from all over the world. The most impressive innovations included active suspension systems, on-board weighing equipment, efficient tire designs and the very latest brake-by-wire and steer-by-wire systems. Inspirational discussions and interesting presentations gave profound insights into the most recent technology. The opportunity for networking at the event allowed for in-depth conversations between representatives of industry, researchers and other experts. It is the variety of themes that makes this event unique. chassis.tech plus 2024 covered the entire bandwidth of chassis technologies from new products to sustainability, from steer-by-wire systems to software and from motion control to brake dust. Six keynote speeches and 49 presentations described the latest developments in the field of chassis and assistance systems. The symposium took place on June 4 and 5, 2024, in the Hotel Bayerischer Hof in Munich and more than 460 people attended. The highlight was a panel discussion with four of the keynote speakers and interactive participation from the audience. Contents Chassis Tech: Chassis and Systems.- Chassis Components.- Market Requirements and Regulatory Demands.- Development Methods.- Driving Simulations.- Artificial Intelligence.- Chassis Control Steering Tech: Innovative Steering Systems.- Development Process and Standardization.- Requirements and Evaluation. Brake Tech: Brake Systems and Control.- Simulation and Testing.- Brake Emissions Tire Wheel Tech: Tire and Wheels and the Environment.- Tire Testing and Simulation. Innovations in Tires and Wheels Target audiences Automotive engineers and chassis specialists as well as students looking for state-of-the-art information regarding their field of activity - Lecturers and instructors at universities and universities of applied sciences with the main subject of automotive engineering - Experts, researchers and development engineers of the automotive and the supplying industry. Partner TÜV SÜD is an international leading technical service organisation catering to the industry, mobility and certification segment.

Inhaltsverzeichnis

Frontmatter

Kapitel 1. Life cycle assessment to identify key levers in order to decrease tire environmental footprint.

Abstract

In order to reduce the environmental footprint of a tyre, and managing the essential performance of the tyre, a method is needed to take into account the transfer of impacts. Michelin presents the life cycle assessment method that allow then to determine the key levers to effectively reduce the global tyre footprint. Results are presented for a internal combustion engine but also battery electric vehicles. Key levers are discussed by order of magnitude and Michelin global approach is presented for the usage part, the design part but also the other levers happening during manufacturing, logistics and end-of-life.

Cyrille Roget

Kapitel 2. ETRTO Abrasion testing with vehicle method – validation results

Abstract

ETRTO (European Tyre & Rim Technical Organisation) is working within the UNECE GRBP framework on a tyre abrasion rate method for regulatory purposes. The feasibility study identified a vehicle test on public roads as a suitable method for passenger car tyres. Validation tests were done on 11 different tyre specifications, tested 4 times each with this method, to estimate test dispersion due to influencing parameters. Test conditions are defined in terms of ambient temperatures, driving style, vehicle settings, reference tyre and measuring intervals. The reported Tyre Abrasion Rate is a relative value versus a fixed reference tyre in tyre weight loss per kilometer driven per carried ton [mg/km/ton].

Benjamin Oelze, Frédéric Biesse

Kapitel 3. Definition and Rating of Green Wheels

Abstract

With a commitment to the 2050 Paris Agreement, the European Union (EU) established a climate and energy framework to reduce net greenhouse gas emissions by at least 55% by 2030. Known as Fit for 55 [1], the EU’s regulations and targets aim to stimulate innovation and speed up the transition to zero- and low-emission mobility.

Europe is not the only governing entity to set carbon reduction targets, nor are vehicle manufacturers only in Europe. Globally, the automotive industry is undergoing a disruptive shift in the journey to sustainability and the entire value chain is under pressure to ramp it up. In its haste to cut emissions and meet targets, the industry has been operating without certain sustainability standards. One such standard is defining how to measure and communicate equivalent emissions at the part level. When an Original Equipment Manufacturer (OEM) is looking to reduce its carbon dioxide equivalent (CO2e) footprint, the wheel, one of the vehicle’s more prominent automotive components, is one of the first parts under consideration.

In this paper, I present and discuss a new wheel CO2e sustainability indicator rating scale and label as a key communication tool for vehicle manufactures and car buyers to quickly understand a wheel’s sustainability contribution.

Karl Rode

Kapitel 4. ABS exploiting forces at the wheel for high performance vehicles and motorsport applications

Abstract

The aim of this paper is to define an innovative Anti-lock Brake System (ABS) for motorsport or hypercar vehicles and compare it with a traditional ABS logic. The comparison is done through a simulation with a complex 14-dof vehicle model, representative of a high-performance sports car. The new ABS is characterized by a sliding mode controller that requires the measurement of the forces at the wheel, precisely, the vertical force, the lateral force, the longitudinal force and the brake torque. The information on tyre forces is used to estimate the tyre-road friction coefficient and use this information to maximize the new ABS performance. The two ABS are compared referring to a full-brake manoeuvre that simulates an emergency stop. Two friction coefficients, referring to dry or wet tarmac road, are considered. The results demonstrate that the new ABS allows to reduce the braking distance with respect to the traditional one, in particular on the low adherence road. The innovative ABS is able to quickly recognize the friction coefficient of the road and modulate the braking torque in order to maintain the wheel slip close to the target and consequently maximize the longitudinal tyre performance.

Matteo Amadini, Carlo Cantoni, Massimiliano Gobbi, Gianpiero Mastinu, Massimiliano Milivinti

Kapitel 5. Tire Wear Particle Evaluation: Outdoor and Indoor

Abstract

Continentals' research and development center investigates tire emissions in the form of Tire and Road Wear Particles (TRWP) intensively. In this paper, the latest measurement evaluations from outdoor and indoor will be presented. The observed influencing factors on the particle size distribution will be discussed. Furthermore, an advanced evaluation concept developed in cooperation with Technische Universität Braunschweig is being introduced.

Nadine Aschenbrenner, Benjamin Oelze, Frank Schmerwitz, Martin Bomkamp, Sven Brandt, Guido Lehne, Frank Schiefer, Georg-Peter Ostermeyer, Carsten Schilde

Kapitel 6. Implementation of a Real-Time ESC Simulation Environment into a Dynamic Driving Simulator (SiL/DiL)

Abstract

The Electronic stability control (ESC) is a safety system that helps prevent vehicle skidding and loss of control. ESC systems are usually tested and calibrated on real vehicles, which is costly and time-consuming. This paper presents a novel approach to implement a serial production ESC simulation environment in a dynamic driving simulator. This allows performing objective and subjective evaluations of the ESC system at an early stage of the development process. The hardware and software components of the real-time simulation environment are described, as well as the integration of the ESC system and validation of its functionality. In a pilot study, expert drivers compared the simulated ESC system with the real one in different driving scenarios. The results show that the simulation environment and therefore the dynamic driving simulator can reproduce the behavior and performance of the real ESC system with high fidelity and accuracy, by providing useful feedback about the driving characteristics and stability of the vehicle. To conclude, the approach could reduce the development time and cost of ESC systems, as well as improve their quality and safety.

Sang Min Park, Matthias Niegl, Tobias Tarne, Anton Tworek, Se Young Cheon, Bernhard Schick

Kapitel 7. Influence of Tire Deformation on the Vehicle Aerodynamics

Abstract

As an irreversible driving resistance, aerodynamic drag has a significant influence on the efficiency and range of vehicles. Up to 25% of the vehicle aerodynamic drag is caused by the wheels and wheel arches. The most important tools for the aerodynamic optimization of vehicles are measurements in the wind tunnel and computational fluid dynamics (CFD). During wind tunnel measurements, tires can deform in the same way as in open road driving. However, due to their complex geometry and deformability in combination with wheel rotation, integrating deformed tire geometries in CFD is a challenge. In a project funded by the Research Association for Automotive Technology (FAT), the University of Stuttgart and the University of Darmstadt are jointly characterizing the flow around the wheel, taking real tire deformation into account. Measurement campaigns in the wind tunnel have shown that tire deformation has a significant influence on aerodynamics. Furthermore, a tire deformation test rig was developed that makes it possible to measure the shape of the rotating tire while rolling on a flat belt and to vary parameters such as wheel load, camber, toe and tire pressure as required. A process was developed which makes it possible to generate tire geometries with real tire deformation for aerodynamic CFD analysis.

Johannes Burgbacher, Timo Kuthada, Felix Wittmeier, Andreas Wagner

Kapitel 8. New Testing Methodologies for Innovative Brake Systems

Abstract

New testing methodologies for mechatronic brake systems are designed to address the complex integration of mechanical and electronic components. These methodologies are essential for evaluating performance and safety under varied and highly dynamic conditions. Particularly outdoor vehicle test programs, such as the Großglockner downhill run for brake performance tests, are being replaced by indoor tests using brake dynamometers (road to rig). This context motivated Volvo, Link and IPG Automotive to build a new and innovative brake test system, which provides brake system engineers with unsurpassed flexibility throughout the development process. This contribution illustrates the development of this system and explains the benefits that can be derived from it in terms of brake performance and effectiveness analysis, braking torque estimation and particulate pollution.

Felix Pfister, Andreas Nygren, Matthijs Klomp, Alessandro Travagliati, Lorenzo Savi, Barry Purtymun, Carlos Ernesto Agudelo

Kapitel 9. A Novel Simulator Setup: Combining Full FTire Dynamics With A High Accurate Steering Feel Emulation

Abstract

This paper introduces an innovative methodology for the evaluation of tire and steering systems, leveraging the integration of the full threedimensional tire model FTire with the well-known Pfeffer steering model under hard real-time conditions on a Driver-in-the-Loop system. The primary objective is to enhance the accuracy in depicting tire-road interactions, including the differentiated feedback communicated to the steering wheel achieved through high accurate modeling of the steering system. A very realistic steering feel emulator is employed to replicate complex sensory feedback inherent in the driver's interaction with the steering wheel. A thorough description of the procedural implementation and subsequent validation of the proposed methodology is provided. Additionally, a first case study is presented, illustrating the advantages transmitted by the consideration of a three-dimensional contact patch and the incorporation of the complete tire dynamics. This integrative approach enables a comprehensive evaluation of both tire and steering system performances across diverse road surfaces and various driving maneuvers.

Benjamin Rieff, Kilian Joerg, Matthias Becker, Korbinian Thaler

Kapitel 10. Validation gap between Hardware- and Software-in-the-Loop brake system simulation

Abstract

The development of brake systems for modern vehicles requires the use of simulation tools to deal with the increasing complexity. In the V model development process, Software-in-the-Loop (SiL) and Hardware-in-the-Loop (HiL) methods are commonly used to test and validate brake system components and functions. Due to the higher technology readiness level at the HiL testing stage, there usually is a gap between the results obtained when simulating SiL and HiL.

By being aware of the discrepancies between SiL and HiL, conclusions can be drawn for the development of the SiL model. This can help optimize the SiL simulation and reduce the validation gap between SiL and HiL simulation. The paper presents a comparative study of a SiL simulation approach and a HiL wet ESC ECU brake system simulation environment for different brake maneuvers, such as normal braking, emergency braking, and anti-lock braking.

The results of the comparison, especially the extent to which the SiL and HiL approaches differ, are discussed in detail. Based on these findings, possible causes for this gap and solutions to minimize it are presented. The paper concludes, that by reducing the validation gap between SiL and HiL simulations, the quality of the SiL simulation is enhanced, and development processes are simplified. This ultimately leads to a reduction of development time and therefore lower cost, while ensuring quality and performance of brake system functions.

Anton Tworek, Tobias Tarne, Raphael Groß, Peter E. Pfeffer

Kapitel 11. Virtual investigation of tire-vehicle handling performances using outdoor and indoor tire characteristics

Abstract

Vehicle dynamics requirements are of major interest in the OE-related tire development process. An efficient and target-oriented development of vehicle dynamics relevant tire characteristics can be supported by using virtual methods and vehicle dynamics simulation. In this article a methodology for a virtual investigation of handling performances with outdoor- and indoor tire models based on a technology project of Volkswagen and Continental is presented.

At first an overview of different methodologies for handling assessment based on outdoor tests and virtual tests in OE-related tire development is given. The comparison of lateral dynamics in linear and nonlinear driving maneuvers is of major interest.

After that an advanced methodology for generating outdoor tire models on basis of vehicle measurements on real road surfaces is presented. A comparison with conventional indoor tire models is done and differences in sideforce characteristics are analyzed.

Finally, a virtual investigation of handling performances of indoor- and outdoor tire models is carried out. The influence of tire model specific properties on the vehicle behavior in the limit area is discussed. An outlook for the future potential of virtual tire-vehicle interaction is presented.

Christian Cramer, Konstantin Sedlan, Carsten Schröder, Heiko Clasen

Kapitel 12. Influence of Powertrain Electrification on Brake Wear Particle Emissions

Abstract

The upcoming Euro 7 regulation encompasses limitations for nonexhaust emissions introducing a new test procedure (UN-GTR No. 24) and a new driving cycle (WLTP brake) for brake emission measurement. Brake PM_10-limits of 7mg/kmV for ICV and hybrid vehicles as well as 3mg/kmV for fully electric vehicles have been defined. Measurements based on standard friction materials (cast iron discs) have shown that these limits can hardly be complied with under current circumstances. This calls for action such as the development of new technologies (coated discs, filtration systems).

Regenerative braking has been identified as one of the greatest potentials for the reduction of particle emissions. Depending on the degree of electrification of the vehicle, a large proportion of the deceleration force can be shifted to the electric motor and must no longer be applied by the friction brakes. Consequently, brake wear and PM₁₀ can be heavily reduced. However, the implementation of the individual generator characteristics into the test bench control systems represents a significant increase in testing effort. The proposed UNGTR No.-24 approach is based on the application of friction braking share coefficients (c-coef.) to the emission factors of a standard full friction brake-test (FFB) depending on the degree of electrification (e.g. NOVC-HEV-C1, OVCHEV, PEV). This bears the risk that the real emission characteristics are not represented correctly.

Within this study the influence of powertrain electrification on brake wear particle emissions is investigated. Therefore, exemplary generator characteristics of NOVC-HEVC1, OVC-HEV and PEV were implemented into an UN-GTR No. 24 compliant brake dynamometer setup. The resulting emission characteristics were evaluated for two different brake systems. In addition, on- and offbrake emissions were differentiated. The results provide insights into the interaction between friction work and emission generation over the course of the WLTP brake cycle. Results show a considerable deviation of emissions factors from the proposed method (c-coef.). Ultimately, an alternative approach for the implementation of regenerative braking should be considered in the future since it clearly gives a more realistic picture of the emissions process. However, first the UN-GTR No. 24 quality criteria need to be adopted (e.g. friction work, number of brake applications etc.).

Toni Feißel, Mirco Augustin

Kapitel 13. Development and manufacturing of aluminium low carbon footprint alloys

Abstract

The utilisation of EN AB 42100 secondary alloys, i.e. AlSi7Mg0,3 alloys containing a high quantity of pre- and post-consumer material, have been tested in the low pressure die casting process for car wheels. Throughout the years different batches with secondary alloys in various ways and mixtures have been cast for two of the main OEMs, AUDI and BMW. This edged in the mass production of one AUDI part number. Such batches underwent a full metallurgical and technological validation proving that mechanical properties (Rp0,2, Rm, A% and hardness) of wheels cast with secondary alloys are comparable to the same part numbers produced with primary ones, despite the chemical composition showing slightly higher Fe, Cu, Mn and Zn content. All technological tests (rotary bending fatigue, 13° impact test, Radialschlag test, ZWARP test and paint tests) showed also good results in line with the validation done on parts made with primary alloys. This activity proved that the utilisation of aluminium alloys with high recycling rate is technically feasible.

Marco Losio, Claudio Sorlini, Roberto Frizzi

Kapitel 14. Anti-lock Brake System (ABS) Enhancement with Intelligent Tires

Abstract

The ABS control system in production vehicles primarily consists of fixed parameters, which are established during the product development phase through extensive testing. The goal is to achieve an optimal performance balance while considering different tire types and operating conditions, including various road and weather scenarios. However, due to the fixed nature of these parameters, the system is unable to fully utilize the maximum braking capability that is achievable. This can result in suboptimal outcomes. Goodyear and TNO have jointly developed a demonstration vehicle serving as a platform to showcase an upgraded ABS controller that leverages data from intelligent tires. This demonstration vehicle showcases new possibilities for enhancing vehicle safety by integrating tire intelligence technology into the ABS controller. Intelligent tires, provide both static details such as tire type and dynamic information like tire pressure, temperature, wheel load, and tread wear state. The prototype ABS is constructed based on a production vehicle, retaining the original hydraulic brake control unit, and incorporating custom firmware for the high-level EBD/ABS controller, as well as low-level brake pressure estimation/control. Employing the sliding mode control principle with a risk-seeking policy, the ABS controller concentrates on wheel acceleration and slip control. Experimental results confirm the effectiveness and potential of intelligent tires in augmenting ABS performance, consequently minimizing the necessity for extensive tuning and testing efforts across diverse vehicle architectures. The modified ABS controller displays adaptability and adjustability, enabling it to effectively cater to varied tire types and operating conditions. By minimizing system uncertainty, intelligent tires have the capability to improve brake performance.

Seyed Amin Sajadi Alamdari, Ron Wouters, Yuri Tielman, Sven Schaefer- O‘Reilly, Kanwar Bharat Singh

Kapitel 15. Research of a long-life brake disk manufactured using a forming process

Abstract

The development of sustainable products and solutions is also becoming increasingly important in the automotive sector. For example, the new Euro 7 emissions standard is expected to regulate particulate emissions from brake systems to a maximum of 7 mg per kilometer for the first time from 2025 [1]. This requirement poses a new challenge for the development of wheel brakes.

The Chair of Vehicle System Design is currently developing a new innovative brake disk with partners from industry and research. Unlike previous brake discs, this one is not made of gray cast iron, but of a corrosion-resistant steel alloy. The advantage of this is that a particularly cost-effective forming process can be used for production. In order to meet the Euro 7 standard, the friction surfaces are provided with a particularly hard wear protection coating. Furthermore, the geometric design of the brake disc is optimized for the use of steel as a material. To this end, extensive FEM simulations and tests were carried out using a dynamometer.

The combination of corrosion-resistant steel and a wear protection layer makes it possible to produce a long-life brake disc. Manufacturing costs can be reduced by using a forming process for production. This enables the brake disc to be used in more cost-effective vehicle segments and still meet the future Euro 7 emissions standard.

Falko Wagner, Ralph Mayer

Titel: 15th International Munich Chassis Symposium 2024
herausgegeben von: Peter E. Pfeffer
Verlag: Springer Berlin Heidelberg
Electronic ISBN: 978-3-662-71062-3
Print ISBN: 978-3-662-71061-6
DOI: https://doi.org/10.1007/978-3-662-71062-3