Browse Topic: Brake-by-wire

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Design and Hardware in the Loop testing of AEB controllers2022-01-010603/29/2022
Current ADAS systems can improve vehicle safety directly influencing its dynamics, reducing the impact of human error while driving. These functionalities have a high impact on the complexity of each unit installed on the car, potentially increasing the development time. In this work, a Hardware in the Loop testing methodology for Autonomous Emergency Braking system is presented, aiming to enable a faster system development process. A commercial production brake by wire unit has been installed on a real-time driving simulator. The AEB functionality of the unit is activable in real-time during the simulation, by the means of a customizable control strategy. Three different AEB controllers have been implemented: the first one reproduces the unit stock functionality, while the two remaining compute the requested deceleration using a PID and a Fuzzy control strategy. The three controllers have been tested in standardized EuroNCAP Car-to-Car Rear (CCR) collision scenarios, implemented on
Alfatti, Federico, Garinei, Michele, Annicchiarico, Claudio, Capitani, Renzo
Research and Development of an Electromagnetic Actuated Active Suspension2019-01-085804/02/2019
Active suspension could achieve good ride comfort and road holding performance. Traditional active suspension which utilizes air actuator or hydraulic actuator features relatively slow response or high energy consumption. Utilizing Permanent Magnet Synchronous Motor (PMSM) as actuator, the Electromagnetic Actuated Active Suspension (EAAS) benefits quick response and energy harvesting from vibration at the same time. Benchmarked with luxury cars available on the market, design parameters and design boundary are determined. A mechanism includes push bar and bell crank is designed to transfer the rotary motion of PMSM into linear motion of suspension, or verse vice. A prototype of EAAS is built in compromise of limited budget and a test bench is designed and set up. Different from conventional quarter car model, the model of EAAS in this paper is investigated and the total inertial of PMSM, gearbox and suspension control arms are calculated and simplified as an equivalent mass. Also
Yin, Jun, He, Jiaxing, Luo, Jie, Chen, Xinbo, Wu, Lixin
2021-12-29.TEST Design and Implementation of Adaptive Range LIDAR System (ARLS) for Autonomous Braking Assistance at High Speeds in Automobiles2018-01-004004/03/2018
Autonomous braking systems are prevalent in mid/upper-mid range vehicles today. The major drawback: acute boundary condition during which the system will function. The paper describes the implementation of Adaptive Range LIDAR Systems (ARLS) containing a state of the art collimator and wave shaper with a 140̊ sweep MEMS mirror, capable of calculating beam convergence as a function of distance, considering multiple obstacles ahead of it. The paper also describes the use of ARLS for ACC (Adaptive Cruise Control) and Autonomous braking, reinforcing the available software structure with more data points. Contrary to the other systems that detect objects/obstacles from a stationary point of reference, ARLS determines the velocity of obstacle with respect to the ground point of reference and computes most optimum brake effort curve. The brake curves are alike for every situation, as it is dynamic in nature, hence, additional electronics ensure physical curve tracing by manipulating the
Mishra, Jainendra
Simulation Based Control Strategy Design of All Wheel Drive Electric Vehicle Regenerative Braking System2018-01-041104/03/2018
Maximising the recovered regenerative braking energy during the deceleration can significantly reduce the Electric Vehicle (EV) energy consumption and increase the range. Compared with the Front Wheel Drive (FWD) or Rear Wheel Drive (RWD) EV, an All Wheel Drive (AWD) EV with 2 electric machines (e-machines) has more control degree freedom when developing the regenerative braking control strategy. By implementing the regenerative braking at the front axle, rear axle, or at the front and rear axles simultaneously, the amount of recovered kinetic energy will be affected. Furthermore, the e-machines at the front and rear axle in the AWD EV can have different sizes or be the same. Therefore, the ratio between front and rear e-machine power rating should also be investigated to understand its effect on the amount of recovered energy during deceleration. This paper starts with the analysis of the vehicle braking behaviour compared over different driving cycles, and the comparison of two
Bao, Ran, Griggs, Philip, Baxter, James
Estimation of Brake Friction Coefficient for Blending Function of Base Braking Control2017-01-252009/17/2017
The brake architecture of hybrid and full electric vehicle includes the distinctive function of brake blending. Known approaches draw upon the maximum energy recuperation strategy and neglect the operation mode of friction brakes. Within this framework, an efficient control of the blending functions is demanded to compensate external disturbances induced by unpredictable variations of the pad disc friction coefficient. In addition, the control demand distribution between the conventional frictional brake system and the electric motors can incur failures that compromise the frictional braking performance and safety. However, deviation of friction coefficient value given in controller from actual one can induce undesirable deterioration of brake control functions. The main objective of the presented study is to propose a method to compensate disturbances induced by variations of brake linings friction coefficient through modifications of the brake torque demand for the enhancement of
Ricciardi, Vincenzo, Savitski, Dzmitry, Augsburg, Klaus, Ivanov, Valentin
Research on Vehicle Stability Control Strategy Based on Integrated-Electro-Hydraulic Brake System2017-01-156503/28/2017
A vehicle dynamics stability control system based on integrated-electro-hydraulic brake (I-EHB) system with hierarchical control architecture and nonlinear control method is designed to improve the vehicle dynamics stability under extreme conditions in this paper. The I-EHB system is a novel brake-by-wire system, and is suitable to the development demands of intelligent vehicle technology and new energy vehicle technology. Four inlet valves and four outlet valves are added to the layout of a conventional four-channel hydraulic control unit. A permanent-magnet synchronous motor (PMSM) provides a stabilized high-pressure source in the master cylinder, and the four-channel hydraulic control unit ensures that the pressures in each wheel cylinder can be modulated separately at a high precision. Besides, the functions of Anti-lock Braking System, Traction Control System and Regenerative Braking System, Autonomous Emergency Braking can be integrated in this brake-by-wire system. A sliding
He, Xiangkun, Yang, Kaiming, Ji, Xuewu, Liu, Yahui, Deng, Weiwen
Development of Advanced Braking System for Hybrid Sports Cars2016-01-192309/18/2016
An advanced braking system had to be developed for a next-generation hybrid sports car with Sport Hybrid Super Handling All-Wheel Drive to achieve an intuitive brake feeling in a variety of driving conditions, ultimate track performance and reduction of CO2 emissions per vehicle. This paper outlines the integration of brake-by-wire with traditional high-performance braking hardware and describes the technology needed to achieve these goals. Key focus areas to generate these results were: brake feeling control, corner hardware specification considerations and brake cooling.
Dyar, Lorne R., Akita, Yuichiro, Paul, Scott, Lepito, Joseph, Ishikawa, Yoshio, Watanabe, Tomohiro
Analysis of Energy Consumption on Typical Main Cylinder Booster Based Brake-by-Wire System2016-01-195509/18/2016
The traditional vacuum booster is gradually replaced by Brake-by-Wire system (BBW) in modern passenger car, especially Electric Vehicle (EV). Some mechanical and hydraulic components are replaced by electronic components in Brake-by-Wire system. Using BBW system in modern passenger vehicles can not only improve the automotive safety performance, reliability and stability, but also promote vehicle maneuverability, comfort, fuel economy and environmental protection. Although vehicle's braking performance is greatly improved by using BBW, the system will inevitably consume some energy of the vehicle power supply, thus introducing unexpected drawback in comparison with the traditional vacuum assist braking system, since it doesn't need any electric power. Therefore, the analysis of energy consumption on typical main cylinder booster based BBW system under typical driving cycles will contribute to advanced design of current advanced braking system. In this paper, energy consumption of the
Yu, Liangyao, Liu, Xiaohui, Liu, Xiaoxue
Fault-Tolerant Control of Brake-by-Wire Systems Based on Control Allocation2016-01-013204/05/2016
Brake-by-wire (BBW) system has drawn a great attention in recent years as driven by rapidly increasing demands on both active brake controls for intelligent vehicles and regenerative braking controls for electric vehicles. However, unlike conversional brake systems, the reliability of the brake-by-wire systems remains to be challenging due to its lack of physical connection in case of system failure. There are various causes for the failure of a BBW system, such as failure of brake controller, loss of sensor signals, failure of communication or even power supply, to name a few. This paper presents a fault-tolerant control under novel control architecture. The proposed control architecture includes a driver command interpreter module, a command integration module, a control allocation module, a fault diagnosis module and state observers. The fault-tolerant control is designed based on a quadratic optimal control method with consideration of actuator constraints. Then a simulation
Liu, Haizhen, Deng, Weiwen, He, Rui, Wu, Jian, Zhu, Bing
Reasons for Turning to Slotless DC Motor TechnologyTBMG-2293209/01/2015
When first introduced, brushless DC motors, despite their many advantages, were cast as a costly alternative to brush-commutated motors, and were typically only specified for low-power applications where long life was the primary desired requirement. Without the mechanical brush-commutator mechanism that would wear and eventually result in motor failure, brushless motors could be relied upon to deliver performance over time. As for other advantages, conventional wisdom held that brushless motors provide high speed and fast acceleration, generate less audible noise and electromagnetic interference, and require low maintenance. Brush-commutated motors, on the other hand, would afford smooth operation and greater economy.
Electro-Mechanical Brake for Front Wheel with Back-up Braking2014-01-253809/28/2014
Electro-Mechanical Brake (EMB) is the brake system that is actuated by electrical energy and has a similar design with the Electric Parking Brake (EPB). It uses motor power and gears to provide the necessary torque and a screw & nut mechanism is used to convert the rotational movement into a translational one. The main difference of EMB compared with EPB is that the functional requirements of components are much higher to provide the necessary performance for service braking such as response time. Such highly responsive and independent brake actuators at each wheel lead to enhanced controllability which should result in not only better basic braking performance, but also improvements in various active braking functions such as integrated chassis control, driver assistance systems, or cooperative regenerative braking. Although the EMB system has the potential for numerous advantages and innovations in braking, it has yet to be successfully introduced in series production mainly due to
Kim, Jongsung, Jo, Chjhoon, Kwon, Yongsik, Cheon, Jae Seung, Park, Soung Jun, Jeon, Gab Bae, Shim, Jaehun
ASURT Formula Student Brake Design2014-01-248709/28/2014
The Braking System is the most crucial part of the racing vehicle. There is no doubt, that if only one minority failure in the braking system took place, this would be more than enough reason to cause the racing team disqualification from the competition. Time is the main and the most important criteria for any racing competition; on the other hand the formula student “FS UK SAE” competition care the most about developing the automotive engineering sense in the students by putting them under strict rules normally taken from the original version “formula 1” to encourage their creativity to reach the optimum performance under these strict rules. One of the most important rules is “No Braking by wire”, and the obvious consequences are more stopping distance and time. Braking distance is a critical facture in achieving racing success in a competitive domain. This report will cover using the bias bar, dynamic weight distribution “before and after braking” and carefully choosing the braking
Barakat, Mohamed Samy
Hardware-in-the-Loop Simulation of Brake-by-Wire Systems with FlexRay Communication2014-01-253009/28/2014
This paper proposes a design approach for the network configuration of brake-by-wire (BBW) systems using the FlexRay communication protocol. Owing to the absence of mechanical or hydraulic back-ups, the BBW system needs to be highly reliable and fault-tolerant. The FlexRay network is shown to be very effective for such requirements of BBW systems by using hardware in-the-loop simulation (HILS), which allows developing and testing various algorithms and faithfully reproduces the actual system. The FlexRay protocols are designed using the FIBEX configuration tool appropriately for the control of BBW systems, and they are analyzed using the FlexRay communication monitoring tool. The results of HILS illustrate that the braking performance of a controller area network (CAN)-based network and that of a FlexRay-based network for BBW systems are very similar, however, the FlexRay-based network system is more reliable and ensures better fault diagnosis by monitoring more variables.
Lee, Kyung-Jung, Kwon, Jae-Min, Cheon, Jae Seung, Ahn, Hyun-Sik
A Strategy to Recycle the Braking Energy of HEV with EMB2014-01-254209/28/2014
Recovering the braking energy and reusing it can significantly improve the fuel economy of hybrid electric vehicles (HEVs).The battery ability of recovering electricity limits the improvement of the regenerative braking performance. As one way to solve this problem, the technology of brake-by-wire can be adopted in the HEVs to use the recovery dynamically. The use of high-power electrical equipment, such as electromechanical brake (EMB), is working in the form of brake-by-wire. Due to the nature of EMB, there exists an obvious coupling relationship between the energy flow and brake force distribution. In this paper, a brake force distribution controller is proposed in HEV with EMB, which can maximize braking energy recovery, compared with the conventional distribution control without EMB. Meanwhile, an energy flow strategy working with the distribution controller is designed, which is less limited to the performance of the battery. In this strategy, the recovery transfers to the motor
Zhou, Liang, Su, Chuqi
Novel Mechanism Using Differential Gears for the Electromechanical Brake2014-01-038404/01/2014
As is well known, the brake systems of vehicles are used in order to decelerate or stop the vehicle while the driving. The operational principle of the brake is the conversion of kinetic energy into thermal energy. In this case, the thermal energy is released to the atmosphere. Recently, electromechanical brakes (EMB) were developed in order to replace hydraulic brake calipers. Such brake-by- wire systems are composed of an electronic pedal, electronic control unit (ECU), wire, and an electromechanical caliper. A typical electromechanical brake is similar to existing floating brakes. In other words, an inner pad pushes out one side of a disc driven by the energy of a motor; by means of a screw-thread gear. Then, the caliper slides in the opposite direction by reaction force and moves the outer pad toward the other side of the disc. Then pads clamp both sides of the rotating disc and stop the wheel. While effective, this design has the problem that there is a difference in the wear of
Park, Tae-Sang, Jin, Sungho, Moon, Jeon IL, Yang, Seung-Han
Regenerative Braking Control Algorithm for an Electrified Vehicle Equipped with a By-Wire Brake System2014-01-179104/01/2014
Regenerative braking, which can effectively improve vehicle's fuel economy by recuperating the kinetic energy during deceleration processes, has been applied in various types of electrified vehicle as one of its key technologies. To achieve high regeneration efficiency and also guarantee vehicle's brake safety, the regenerative brake should be coordinated with the mechanical brake. Therefore, the regenerative braking control performance can be significantly affected by the structure of mechanical braking system and the brake blending control strategy. By-wire brake system, which mechanically decouples the brake pedal from the hydraulic brake circuits, can make the braking force modulation more flexible. Moreover, its inherent characteristic of ‘pedal-decouple’ makes it well suited for the implementation in the cooperative regenerative braking control of electrified vehicles. With the aims of regeneration efficiency and braking performance, a regenerative braking control algorithm for
Lv, Chen, Zhang, Junzhi, Li, Yutong, Yuan, Ye
Multi-Objective Optimization and Robust Design of Brake By Wire System Components2013-01-205909/30/2013
A Brake By Wire (BBW) system is generally composed of electro-mechanical calipers at each wheel, a pedal simulator and a central controller. The brake demand is processed by the pedal and the central controller commands the brake distribution for each brake actuator. The highly responsive and independent brake actuators lead to enhanced controllability which should result in not only better basic braking performance, but also improvements in various active braking functions such as integrated chassis control, driver assistance systems, or cooperative regenerative braking. Although the BBW system has the potential for numerous advantages and innovations in braking, it has yet to be successfully introduced in series production mainly due to safety and cost concerns. Recent studies have been made to investigate the functional safety aspects and additional mechanical backup measures in this regard. Another area that needs to be considered is the optimization of key BBW system components to
Kwon, Yongsik, Kim, Jongsung, Cheon, Jae Seung, Moon, Huyng-il, Chae, Ho Joong
SAE Off-Highway Engineering 2013-07-1113OFHD071107/11/2013
Optimizing brake-by-wire control An optimal control strategy is introduced that ensures minimum control effort that results in minimum actuator power consumption, while simultaneously providing efficient braking performance.
A Control Allocation Algorithm for Improving the Fail-Safe Performance of an Electric Vehicle Brake System2013-01-018704/08/2013
The ample electrical power supply makes brake-by-wire technology more suitable for application in electric vehicles than in conventional vehicles. The fail-safe performance of a brake-by-wire system is a key factor regarding its application on production vehicles. A new control allocation algorithm for improving the fail-safe performance of an electric vehicle brake system is proposed. The electric vehicle is equipped with a four-wheel independent brake-by-wire and steer-by-wire system. The main objective of the algorithm is to maintain the vehicle braking performance as close to the desired level as possible by reallocating the control inputs to the actuators in cases of partial or full failure of the brake-by-wire system. The control algorithm is developed using a two degrees of freedom vehicle model. A pseudo control vector is calculated by a sliding mode controller to minimize the difference between the desired and actual vehicle motions. A pseudo-inverse controller then allocates
Feng, Chong, Ding, Nenggen, He, Yongling, Xu, Guoyan, Gao, Feng
An Approach to Vehicle Brake-By-Wire Optimal Control Tracking Strategy2013-01-068604/08/2013
In this paper, an optimal control tracking strategy for a brake-by-wire system is developed and tested on a laboratory setup consisting of a driving motor, clutch and gearbox system, rotating inertia and an electro-mechanical brake actuator. The presented brake by wire system consists of a brake pedal sub-system connected to the electro-mechanical brake actuator through an electronic control module handling the optimal control logic. A mathematical model of the proposed brake-by-wire control system is presented. The presented mathematical model is simulated and validated against the experimental data. The good agreement between both simulation results and experimental validates the mathematical model. The validated mathematical model is then used to test the proposed optimal control tracking strategy against different levels of disturbances that are difficult to emulate in the laboratory. The developed control logic ensures optimal control effort of the electro-mechanical brake
Haggag, Salem A., Abidou, Diaa
New Brake By Wire Concept with Mechanical Backup2012-01-180009/17/2012
Brake-By-Wire (BBW) is a term used to describe next generation brake systems that rely on motor driven electro-mechanical calipers in place of conventional hydraulic components such as the booster, master cylinder, hydraulic unit, and parking brake. Instead the system configuration is simplified to a pedal simulator, electro-mechanical calipers that require no boosting, and electric control units. The active, highly-responsive, and independent control of the brake actuators at each wheel allows for great control flexibility and improved brake performance. It is also very well-suited for easy integration with cooperative regenerative braking and driver assistance functions. Although such potential and innovations have driven the interest and research into BBW systems through the years, it has yet to be successfully introduced in series production mainly due to the underlying perception of the lack of reliability of electronic components and overall cost concerns. In the current
Cheon, Jae Seung, Kim, Jongsung, Jeon, Jaehan
A New Approach to the Electronic Wedge Brake2012-01-180109/17/2012
The aim of this research is to develop a new electronic braking system based on an electric powered controlled friction brake with high self-reinforcement capability which has performance advantages over the conventional electromechanical brake systems. To avoid jamming, a special control technology was developed. Thus, by intelligently controlling a brake wedge, the kinetic energy of a vehicle is transformed into braking power. The physical effects involved, lead to a significant reduction of energy consumption of the brake actuator compared to “conventional” brake-by-wire systems. The performance of the “Electronic Wedge Brake” (EWB) in a vehicle was studied using a quarter vehicle model. A sliding mode controller was designed for an optimum wheel slip control, and the control simulation results show significant shorter braking distance in comparison to other conventional braking systems.
Ghajari, Amirhossein, Kazemi, Reza
Co-operative Control of Regenerative Braking using a Front Electronic Wedge Brake and a Rear Electronic Mechanical Brake Considering the Road Friction Characteristic2012-01-179809/17/2012
In this study, a co-operative regenerative braking control algorithm was developed for an electric vehicle (EV) equipped with an electronic wedge brake (EWB) for its front wheels and an electronic mechanical brake (EMB) for its rear wheels. The co-operative regenerative braking control algorithm was designed considering the road friction characteristic to increase the recuperation energy while avoiding wheel lock. A powertrain model of an EV composed of a motor, and batteries and a MATLAB model of the control algorithm were also developed. They were linked to the CarSim model of the vehicle under study to develop an EV simulator. The EMB and EWB were modeled with an actuator, screw, and wedge to develop an EMB and EWB simulator. A co-simulator for an EV equipped with an EWB for the front wheels and an EMB for the rear wheels was fabricated, composed of the EV and the EMB and EWB simulator. The co-simulator was used to evaluate the performance of the proposed regenerative braking
Ko, Jiweon, Lee, Gaeun, Ko, Sungyeon, Ahn, Sunghyun, Kim, Hyoungjin, Choi, SeokHwan, Kim, Hyunsoo, Kim, Insu, Jeong, JongYun, Hyun, Dongyoon
Sensor Fault Diagnosis for EMB using Parity Space Approach2012-01-179409/17/2012
In future automobiles, conventional hydraulic brakes can be removed and be replaced by electrically operated brakes called brake-by-wire. The brake-by-wire units such as EMB(Electro-Mechanical Brake) provide better performance in braking by directly controlling the brake motor and are environmentally friendly without hydraulic fluid. Since the brake is safety-critical, the EMB should be reliable in its lifetime and robust fault diagnosis techniques should be included. Many researches have been carried out to develop the diagnosis techniques to improve their robustness and reliability. In this study, a fault size detection method is proposed with the parity space approach for the EMB system. In order to detect and isolate sensor faults from the residual, the residual generator is constructed. The model-based fault diagnosis system is developed for the EMB sensors; current sensor, position (or speed) sensor and clamping force sensor. The proposed system is verified through the closed
Hwang, Woohyun, Huh, Kunsoo, Kim, Myoungjune, Jung, Jihyun
Effects of Titanates in Low Steel Formulation: Prevention of Metal Pick Up Growth2012-01-178509/17/2012
Titanates are currently used in friction materials worldwide. This study investigates the effects of titanates in friction materials with Low Steel (LS) formulations. A kind of titanate compound is examined with a LS formulation. Test pieces both with and without the titanate are examined using small rotors of gray cast iron. The frictional performance tests use a 1/7 scale dynamometer. The surfaces and the cross-sections are closely observed using a Scanning Electron Microscopic analyzer. Results of the testing on samples without the titanate suggest that frictional effectiveness is sensitive to the load value especially in high speed braking conditions. A Metal Pick Up (MPU) phenomenon, which is one of the significant problems of friction materials, also occurs. The millimeter-sized picked-up metals consist of micron-sized wear debris of iron. The crystalline transformation of the steel fibers around the picked up metals is investigated. Results show that the crystalline structure of
Kamada, Shogo, Inada, Kousuke
Development of Smart Booster Brake Systems for Regenerative Brake Cooperative Control2011-01-235609/18/2011
In regenerative braking, the kinetic energy of the vehicle is stored in a battery as the electric energy that is otherwise being dissipated as heat by friction, so that the stored energy is recuperated to drive the vehicle. In general, another independent braking mechanism, such as hydraulic brakes, needs to be used in cooperation with regenerative braking in order to meet the total braking force demand. The smart booster system, which uses a permanent magnet synchronous motor to replace the conventional vacuum booster, is proposed in this paper as an active braking system which is well suited for such regenerative cooperative braking applications in environment friendly vehicles. A pressure feedback control is used with a nested current control loop using pressure and current sensors, respectively. Two types of smart booster systems are investigated for different applications, and the samples of both types of smart booster systems are built to check the feasibility of the proposed
Yeo, Hoon, Koo, Changhoe, Jung, Wankyo, Kim, Dokun, Cheon, Jae Seung
Brake By Wire Functional Safety Concept Design for ISO/DIS 262622011-01-235709/18/2011
The importance of functional safety design has recently grown with the increasing widespread application of electric/electronic (E/E) systems in today's automotive industry. Such E/E systems, usually composed of mechatronic actuators, various sensors, and electronic control units (ECU), have become too complex to be handled in the conventional quality management manner that was used for most predominantly mechanical applications. ISO/DIS 26262, an adaptation of the pre-existing IEC 61508 requirements specifically for the automotive industry, has been prepared as the global standard to meet such demands for a more structured and systematic approach to functional safety design. The functional safety concept design includes a hazard analysis and risk assessment phase that is based on ASIL (Automotive Safety Integrity Level) categorization. ASIL has four levels, A, B, C, and D, where A has the lowest risk and D has the highest. In this study, the concept phase of this ISO26262 standard for
Cheon, Jae Seung, Kim, Jongsung, Jeon, Jaehan, Lee, Sang Mok
Fuzzy System for Fault Diagnostics in Power Electronics-Based Brake-by-Wire SystemTBMG-494902/01/2009
Research in fuzzy diagnostics of brake-by-wire systems focuses on the power electronics switches, since they are often considered to be the weakest link in the system. The objective of fault diagnostics in the power electronics of the brake-by-wire system is to accurately locate any faults within the circuit as soon as they occur.
Turbohybrid - The Realisation of a Holistic Approach for a Modern Gasoline Hybrid Drive2009-26-004201/21/2009
The fuel economy benefits of hybrids have been accepted for long. However their drivability has not been found very acceptable. This paper present a holistic approach which resulted in the development of a Gasoline Turbocharged Hybrid vehicle that not only produced the fuel economy benefits associated with hybridization but also provided driving characteristic of a “fun to drive” vehicle. A comparison of the benefits of the developed Turbohybrid Gasoline vehicle over its base vehicle configuration as well as the later day model of the base vehicle shows the improvements that have been possible in both fuel economy as well as the fun to drive aspect.
Schneider, R., Ellinger, R, Ebner, P., Nair, C. K. J.
Modeling and Control of a Single Motor Electronic Wedge Brake2007-01-086604/16/2007
Siemens VDO is currently developing a brake -by-wire solution called the Electronic Wedge Brake (EWB). Earlier prototypes used a two -motor concept inside the brake actuator to drive the wedge. In this paper, a new prototype generation is presented where only one motor is needed. This is more efficient in terms of cost, and actuator weight, and also reduces the complexity of the control strategy. A state -space model is derived for the new actuator and two controller structures are explained. Simulations and experimental results from a roller test bench are shown.
Fox, J., Roberts, R., Baier-Welt, C., Ho, L. M., Lacraru, L., Gombert, B.
Semiconductor Solutions for Braking Systems: New Partitioning and New Safety Concepts Increase Safety and Reduce System Cost2004-01-025103/08/2004
Braking systems require a high system safety level: New safety concepts need to be implemented by reducing the system complexity. Microcontrollers with special safety functions are available with implemented features, self detecting and compensating different types of faults. Today usually two microcontrollers are used to check each other. Power devices provide microcontroller supplies and drive motors and valves; internally the functions are supervised to avoid incorrect system behaviour due to wrong voltages, currents, missing loads or other malfunctions. Bus interfaces, signal conditioning and interfaces for high voltage signals are integrated into the power system ICs. Latest BIPOLAR-CMOS-DMOS power technologies enable the power semiconductors to integrate logic functions. This capability drives new partitioning of power ICs and microcontroller in ABS and ESP systems: Calculation tasks and microcontroller supervision functions migrate from the microcontroller into the power devices
Diermeier, Andrea, von Wendorff, Wilhard
Beyond ABS - Brake by Wire Development of a Working Concept2003-28-001008/22/2003
Introduction of more and more electronics control into automobiles has been gaining ground over the last three decades. Electronically controlled braking for improved safety on roads has been in Europe and US since late 70's in the form of Anti-skid Braking System called ABS. “Brake By Wire” systems named EBS for heavy vehicles were introduced in the European market in 1995 as advancement over ABS. This paper briefly describes the efforts by Sundaram Clayton Limited (SCL) to develop an indigenous working concept of a “Brake by Wire’ System for commercial vehicle applications.
Raman, S., Khannan, B. Shylandra, Mahalingam, M.V.
Power Line Communication Implementation in Electrical Architecture2003-01-022603/03/2003
The implementation of the new electronic equipment makes the electrical and electronic architecture more and more complex. Thus technologies such as Power Line Communication constitute alternative solutions to reduce the number of wires and optimize the harness. Taking into account the know how and applications for household use, the power line communication feasibility in automotive domain had to be performed. This paper deals with the essential parameters to be identified in order to provide the appropriate power line modulation. Harness EMC behavior and EMI disturbances inside vehicle are developed in this paper.
Laliron, Anne, Maurice, Olivier, Gascher, Alain
A Sliding Mode Observer Based ABS for Aircraft and Land Vehicles2003-01-025203/03/2003
Control of an antilock brake system for aircraft and land vehicles is based upon estimates of the torque applied to braking wheels by means of a sliding mode observer. The observer yields a highly accurate estimate of torque that is robust for the entire operating range of the brakes, and provides an input to a relatively simple control system that regulates applied torque from either an electro-hydraulic or electromechanical actuator. Excellent braking performance for a regional jet transport is demonstrated in this paper via hardware-in-the-loop simulation. A simple scheme for suppressing gear walk (aircraft application) is presented.
Ribbens, William B., Fredricks, Ron
An Original Method to Predict Brake Feel: A Combination of Design of Experiments and Sensory Science2003-01-059803/03/2003
A brake by wire research vehicle was developed and equipped with an electrical active pedal feel emulator. With this device, the relationships between brake pedal force, pedal travel and vehicle deceleration are fully adjustable. We can tune 11 technical parameters (7 for the force/travel pedal relationship and 4 for the deceleration/travel relationship). A Plackett-Burman design of experiments was used to generate 12 unique braking laws. These laws were evaluated by a sensory descriptive analysis panel on seven criteria. Partial Least Square (PLS) analysis was used for data treatment. This analysis sorted out the most influential technical parameters on brake feel. As a result, a software application able to predict brake feel using technical parameters was implemented.
Dairou, Victoire, Priez, Alain, Sieffermann, Jean-Marc, Danzart, Marc
Customer Orientation: A Further Target in Brake System Design2003-01-059903/03/2003
The attention to the perceived quality, e.g. the quality as it is evaluated by the final customer, is becoming more and more important for the car makers. The paper describes how such aspects of braking system feel quality, joined with brake thermal constraints and interactions with other vehicle subsystems, such as suspensions, tyres and rims, can become manageable by an engineering process. In order to do that experienced designers define: longitudinal brake performance, stability limits in braking in a turn by comparison with referenced cars; brake thermal constraints; brake system constraints due to interactions with other vehicle subsystems. For perceived quality, on the other hand, it's necessary to take a different kind of approach in order to define targets. Some fundamental and different steps are necessary: the definition of measurable performance for the subjective aspects; the identification of the target values for such aspects coherent with product positioning; the
Pascali, Leonardo, Ricci, Claudio, Caviasso, Guglielmo, Petruccelli, Luigi
Electrical Drives Work as Virtual Sensors in Cars2000-05-003106/12/2000
An innovative method for the use of electrical machines and drives as sensors in automotive applications is presented. The innovations and advantages resulting out of the described procedures are superior diagnostic capabilities. As a main result higher efficiency and reliability of electrical machinery and mechanical systems in cars may be obtained. An accurate failure recognition of electrical and electromechanical components and systems in a pre-failure-phase is possible, so there is an opportunity for preventive exchange of parts and systems. The presented diagnostics methods, contains not only the opportunity for time- and cost-optimised car service, but also for additional functionalities in electromechanical systems working with drives.
Gospodaric, Davor, Jajtic, Zeljko, Iamandi, Heiko, Ditzer, Erich
Embedded Real Time Operating Systems and the OSEK Standard2000-01-038203/06/2000
In recent years the growth of distributed architectures in automotive electronics has been well documented. It is not uncommon for advanced vehicles to contain more than 70 individual Electronic Control Units (ECU's). The use of embedded processors to gain enhancements in comfort and safety, as well as to achieve legislative requirements, has meant that the software content in vehicles has now become a significant part of the system design. This paper looks at some of the issues for the designer of embedded automotive systems and looks at the OSEK/VDX 1 standard (Open systems and the corresponding interfaces for automotive electronics) as a way of providing a framework for addressing them.
Brook, David
OSEK Communications and Network Management on CAN and J1850: Software Implementation and Configuration2000-01-055503/06/2000
This paper describes the use of an OSEK/VDX Real-Time Operating System (RTOS) and the implementation of an OSEK compliant communication protocol, layered on the CAN Bus or the SAE J1850 standard, that supports a distributed framework. The paper provides an overview of the OSEK/VDX specification and examines the application programming interface (API) and the code generation software necessary to configure and implement a distributed control system. The paper will use a simple illustration to demonstrate the implementation process, providing example OIL and C files.
Foster, Neale, Zorbas, Aylu
Future Electrical Steering Systems: Realizations with Safety Requirements2000-01-082203/06/2000
Additional future requirements for automobiles such as improved vehicle dynamics control, enhanced comfort, increased safety and compact packaging are met by modern electrical steering systems. Based on these requirements the new functionality is realized by various additional electrical components for measuring, signal processing and actuator control. However, the reliability of these new systems has to meet the standard of today's automotive steering products. To achieve the demands of the respective components (e.g. sensors, bus systems, electronic control units, power units, actuators) the systems have to be fault-tolerant and/or fail-silent. The realization of the derived safety structures requires both expertise and experience in design and mass production of safety relevant electrical systems. Beside system safety and system availability the redundant electrical systems also have to meet economic and market requirements. Within this scope the paper discusses three different
Harter, Werner, Pfeiffer, Wolfgang, Dominke, Peter, Ruck, Gerhard, Blessing, Peter
Vehicle Dynamics Control for Commercial Vehicles97328411/17/1997
This paper presents the Vehicle Dynamics Control (VDC) for commercial vehicles developed by BOSCH. The underlying physical concept is discussed in the second section after a short introduction. The third section shows the computer simulation used in the development process. Section four describes the controller structure of the VDC system. In Section five the use and effectiveness of VDC for commercial vehicles is shown in different critical driving situations. This is done by using measured data collected during testing (lane change, circular track) and it demonstrates that the safety improvements achieved for passenger cars are also possible for commercial vehicles.
Hecker, F., Hurnrnel, S., Jundt, O., Leirnbach, K. -D., Faye, I., Schramm, H.
Design of a Brake by Wire System Using OOA96099202/01/1996
The design of complex real time embedded systems such as Brake by Wire is becoming increasingly difficult as more and more functionality is added. A technique is required whereby previous experience can be used to develop future products in shorter time scales whilst maintaining the fidelity of a system. The technique should also be able to cope with the inevitable changes to the product over time. This paper describes the use of Object Oriented Technology for the rigorous analysis of a complete system. The resulting model can be used to simulate the behaviour of the system in normal and abnormal conditions, whilst final code may be generated directly from the model and executed on target hardware.
Singh, Manjinder, Bridgens, Barry
Demand Criteria on Retarders92245311/01/1992
In order to increase the average road speeds of heavy duty commercial vehicles on flat roads and during uphill passages more powerful engines are continuously installed by the vehicle manufacturers. During downhill passages the average road speed has to be increased just as well, whereby the service braking system of a vehicle is subjected to extreme performance requirements. This fact leads to an intensified continuation in the development work and the augmented use of wear-free brakes. The most diversified retarder types have been known for some time now, however, the requirements demanded on these wear-free retarders have risen quite drastically during the last years due to economic and safety related reasons. Not only a conceivably simple integration into the vehicle braking system is demanded on the retarders, but also high braking power covering the entire road speed range. Low weight ratings and simple operation by the driver are only a few additional characteristics which have
Haiss, Johannes
State of Development and Future Prospects of Hydrodynamic Brakes for Trucks and Buses92245411/01/1992
In the last 20 years, in western Europe, the power capability of commercial vehicles has doubled, whereas the braking power available has only increased by 40%. Due to the emphasis on economy, safety and increasing traffic density, the importance of continuous braking systems for trucks and busses is of growing significance. Voith has developed a new line of hydrodynamic continuous braking systems for commercial vehicles for installation on tractors as well as trailers. These solutions offer the possibility of integration into the powertrain's management system.
Bergmann, Uwe, Kahlau, Gerhard E., Vogelsang, Klaus, Höller, Heinz
Brake by Wire for Commercial Vehicles92248911/01/1992
This address presents the ongoing development of the commercial-vehicle braking system, over and beyond ABS/ASR, towards a brake by wire system (electronically controlled braking system ELB) with pressure-regulating circuit and additional functions. Following the discussion and selection of various concepts, we will present different versions with individual and combined components for the towing vehicle and for the trailer. The safety concept of a pneumatic back-up circuit will be dealt with, as well as the communication through data bus (CAN) both within the braking system itself and with other vehicle systems. The improvement possibilities inherent in ELB will be detailed, with the emphasis on increasing road and traffic safety, on reducing operating costs, and on future vehicle-guidance functions.
Wrede, Jürgen, Decker, Heinz
Antilock Braking Systems (ABS) for Commercial Vehicles - Status 1990 and Future Prospects90117710/01/1990
The paper begins with an overview of the history of ABS for commercial vehicles followed by a brief description of the technology of the BOSCH ABS at the time it went into mass production in 1981. Subsequently it describes the field experiences with ABS including the experiences of drivers and operators. These experiences are reflected in the equipment which BOSCH offers today. Additional functions such as ASR (traction control) have been integrated. The paper provides an overview of the functions available today and their implementation. The paper concludes with a discussion on potential continued developments and an attempt to describe the systems which will be required by the mid 9os.
Emig, Reiner, Goebels, H., Schramm, H. J.
Development, Status and Future Trends for Hydraulic Brake Boosters83041402/01/1983
Hydraulic brake boosters will assume an increasingly important role, as the need for power assistance independent of the vehicle’s engine increases. Also, the combination of other functions such as Anti Skid Actuation, Self-Leveling Suspensions, can lead to overall cost effective systems. The Paper covers the development background through duo-medium systems using steering pump as a power source to the latest single-medium high pressure H 21 system. The paper explains the compact integrated design of the unit and concludes by considering middle to long-term brake system development which would include a greater use of electronics.
Klein, Hans-Christof
Fluid Power and Control Requirements for the Space Shuttle Orbiting Vehicle73098602/01/1973
The Space Shuttle Orbiter Vehicle is a combination spacecraft and aircraft which can remain in orbit for 7 days and also fly horizontally and land on existing SAC type airport runways. The vehicle utilizes gimbaling of the main rocket engines and rudder control during ascent and aerodynamic surfaces for control during re-entry, approach and landing. A hydraulic system was selected for actuation of those controls and for actuation of the landing gear, brakes, steering, and main engine control valves. This paper discusses system characteristics, power requirements and maintenance features of the Orbiter Hydraulic system. The hydraulic system goal for design is to provide vehicle reliability and serviceability comparable to aviation standards.
McGillen, Vernon, Rosenbaum, Bernhard
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