Browse Topic: Electronic brake controls

Items (104)

Modeling and Identification of an Electric Vehicle Braking System: Thermal and Tribology Phenomena Assessment

2020-01-109404/14/2020

A rapidly shifting market and increasingly stringent environmental regulations require the automotive industry to produce more efficient low-emission Electric Vehicles (EVs). Regenerative braking has proven to be a major contributor to both objectives, enabling the charging of the batteries during braking and a reduction of the load and wear of the brake pads. The optimal sizing of such systems requires the availability of good simulation models to improve their performance and reliability at all stages of the vehicle design. This enables the designer to study both the integration of the braking system with the full vehicle equipment and the interactions between electrical and mechanical braking strategies. This paper presents a generic simulation framework for the identification of thermal and wear behaviour of a mechanical braking system, based on a lumped parameter approach. The thermal behaviour of the system is coupled back to the friction coefficient between the pad and the disk

D’hondt, Thomas, Forrier, Bart, Sarrazin, Mathieu, Favilli, Tommaso, Pugi, Luca, Berzi, Lorenzo, Viviani, Riccardo, Pierini, Marco

Fault-Tolerant Control of Regenerative Braking System on In-Wheel Motors Driven Electric Vehicles

2020-01-099404/14/2020

A novel fault tolerant brake strategy for In-wheel motor driven electric vehicles based on integral sliding mode control and optimal online allocation is proposed in this paper. The braking force distribution and redistribution, which is achieved in online control allocation segment, aim at maximizing energy efficiency of the vehicle and isolating faulty actuators simultaneously. The In-wheel motor can generate both driving torque and braking torque according to different vehicle dynamic demands. In braking procedure, In-wheel motors generate electric braking torque to achieve energy regeneration. The strategy is designed to make sure that the stability of vehicle can be guaranteed which means vehicle can follow desired trajectory even if one of the driven motor has functional failure. Considering longitudinal velocity and yaw rate control, Electric vehicle with four independent In-wheel driven motor is a typical over-actuated control system whose control inputs outnumbers the state

Ji, Yuan, Zhang, Junzhi, Liu, Weilong, Hou, Xiaohui

A Safety and Security Testbed for Assured Autonomy in Vehicles

2020-01-129104/14/2020

Connectivity and autonomy in vehicles promise improved efficiency, safety and comfort. The increasing use of embedded systems and the cyber element bring with them many challenges regarding cyberattacks which can seriously compromise driver and passenger safety. Beyond penetration testing, assessment of the security vulnerabilities of a component must be done through the design phase of its life cycle. This paper describes the development of a benchtop testbed which allows for the assurance of safety and security of components with all capabilities from Model-in-loop to Software-in-loop to Hardware-in-loop testing. Environment simulation is obtained using the AV simulator, CARLA which provides realistic scenarios and sensor information such as Radar, Lidar etc. MATLAB runs the vehicle, powertrain and control models of the vehicle allowing for the implementation and testing of customized models and algorithms. Real-time simulation and connectivity with external components are obtained

Appel, Matthew, Oruganti, Pradeep Sharma, Ahmed, Qadeer, Wilkerson, Jaxon, Sekar, Rubanraj

Electronic Control of Brake and Accelerator Pedals for Precise Efficiency Testing of Electrified Vehicles

2020-01-128204/14/2020

Efficiency testing of hybrid-electric vehicles is challenging, because small run-to-run differences in pedal application can change when the engine fires or the when the friction brakes supplement regenerative braking, dramatically affecting fuel use or energy regeneration. Electronic accelerator control has existed for years, thanks to the popularity of throttle-by-wire (TBW). Electronic braking control is less mature, since most vehicles don’t use brake-by-wire (BBW). Computer braking control on a chassis dynamometer typically uses a mechanical actuator (which may suffer backlash or misalignment) or braking the dynamometer rather than the vehicle (which doesn’t yield regeneration). The growth of electrification and autonomy provides the means to implement electronic brake control. Electrified vehicles use BBW to control the split between friction and regenerative braking. Automated features, e.g. adaptive cruise control, require BBW to actuate the brakes without pedal input. We

Gross, Michael C., Hamermesh, Jonathan, Jonson, Kyle, Alden, Joshua

Vehicle E/E Architecture and Its Adaptation to New Technical Trends

2019-01-086204/02/2019

With the ever-increasing requirements on vehicle performance, as well as the trend of vehicle becoming an integral part of a much bigger ecosystem involving automated driving, intelligent transportation and smart city, more and more electrical/electronic (E/E) systems are integrated in vehicles. Vehicle E/E architecture being the fundamental organization of E/E components, the relationship among the components and with the environment, as well as the principles guiding the design and evolution, has essential influences on vehicle E/E system functions and performance. This paper gives the definition of vehicle E/E architecture and provides different views. The guidelines, contents and process of E/E architecture design are discussed. The evolution of E/E architecture, influence of the latest technical trends including electrification, automated driving, and connectivity functions on E/E architecture, and how vehicle E/E architecture adapts to the technical trends are studied.

Jiang, Shugang

Study on a Method for Evaluating the Safety of the Braking Control Algorithm for Automated Driving System When Following

2019-01-101504/02/2019

The purpose of this study is to develop a method for evaluating the safety of the braking control algorithm for automated driving under mixed traffic flow of automated driving system and vehicles driven by drivers. We consider that the automated driving system should be controlled such that it blends in with mixed traffic. Therefore, in evaluating the safety of braking control for the automated driving system when following, the influence of the automated driving system on the driver of the following vehicle is an important evaluation index. First, we analyzed past traffic accidents in Japan to determine a suitable traffic environment for evaluating the safety of the braking control algorithm for the automated driving system when following. Second, the driver’s braking operations were measured using actual vehicles in this situation. We developed a method of generating sample algorithms of braking control based on the driver’s braking operations. Finally, we developed a method of

Gokan, Masato, Tanaka, Nobuhisa, Furukawa, Yoshimi, Iwase, Tunetoshi, Hirowatari, Taichi

Research on Regenerative Braking Control Strategy of Distributed EV based on Braking Intention

2018-01-134204/03/2018

Focusing on distributed electric vehicles with in-wheel motors, a novel regenerative braking control strategy based on braking intention is proposed. Firstly, a design scheme for the regenerative braking system is described. Four in-wheel motors and an Electro-Hydraulic Braking (EHB) system are respectively designed for regenerative braking and hydraulic braking. Then, Braking intention recognition self-learning libraries are trained based on Hidden Markov Model method, which is validated by driver-in-loop tests. According to three speed states and four braking intentions, the regenerative braking control strategy for multiple brake modes is developed. The coefficient of regenerative braking is defined to describe the intervening time and proportion of motor maximum regenerative braking. Eventually, the co-simulation results show that the proposed strategy can not only significantly improve the energy recovery capability, but also provide the coordinated control of regenerative braking

Pan, Hao, Guo, Xuexun, Pei, Xiaofei, Pan, Jin, Zhang, Jie

Research on a Novel Electro-Hydraulic Brake System and Pressure Control Strategy

2018-01-076404/03/2018

Based on the research and analysis of the current brake systems, this paper presents a novel electro-hydraulic brake system, which can better meet the functional requirements. The system mainly contains a master cylinder, two brake hydraulic cylinders and drive motors, two transmission mechanisms, thirteen solenoid valves, pedal force simulator, etc. Since the proposed brake system uses a dual motor along with two brake hydraulic cylinders, it has advantages in providing fast pressure response, flexible working modes, high precision and strong fault tolerance. In order to facilitate the study of pressure control algorithm for the proposed brake system, a mathematical model of the brake system is firstly established, then a multiplexed time-division pressure control algorithm is proposed to realize the simultaneous or partially simultaneous pressure control, which ensures the high precision and short response time. Finally, based on the model of the proposed brake system, some extensive

Liu, Haizhen, He, Rui, Deng, Weiwen, Yang, Shun, Wu, Jian, Chen, Pengcheng

Development of General Motors’ eAssist Gen3 Propulsion System

2018-01-042204/03/2018

General Motors’ 3rd generation eAssist propulsion systems build upon the experience gained from the 2nd generation 115v system and the 1st generation 36v system. Extensive architectural studies were conducted to optimize the new eAssist system to maintain the performance and fuel economy gains of the 2nd generation 115v system while preserving passenger and cargo space, and reducing cost. Three diverse vehicle applications have been brought to production. They include two similar pickup trucks with 5.3 liter V8 engines and 8 speed transmissions, a 4-door passenger car with 2.5 liter 4 cylinder normally aspirated gasoline engine and a 6-speed automatic transmission, and a crossover SUV with a 2.0-liter turbocharged engine and 9 speed transmission. The key electrification components are a new water cooled induction motor/generator (MG), new water cooled power electronics module, and two major variants of 86v lithium ion battery packs. All three applications share variations of the same

Cottrell, Daniel, Miller, Michael Andrew, Oury, Andrew, Staley, Eric, Mui, Danny, Osterkamp, Dale, Poulos, Stephen

Autonomous Emergency Braking Control Based on Hierarchical Strategy Using Integrated-Electro-Hydraulic Brake System

2017-01-196409/23/2017

Highway traffic safety has been the most serious problem in current society, statistics show that about 70% to 90% of accidents are caused by driver operational errors. The autonomous emergency braking (AEB) is one of important vehicle intelligent safety technologies to avoid or mitigate collision. The AEB system applies the vehicle brakes when a collision is eminent in spite of any reaction by the driver. In some technologies, the system forewarns the driver with an acoustic signal when a collision is still avoidable, but subsequently applies the brakes automatically if the driver fails to respond. This paper presents the development and implementation of a rear-end collision avoidance system based on hierarchical control framework which consists of threat assessment layer, wheel slip ratio control layer and integrated-electro-hydraulic brake (IEHB) actuator control layer. The threat assessment layer continuously calculates threat metrics associated with collision avoidance by braking

He, Xiangkun, Ji, Xuewu, Yang, Kaiming, Liu, Yulong, WU, Jian, Liu, Yahui

Research on Vehicle Stability Control Strategy Based on Integrated-Electro-Hydraulic Brake System

2017-01-156503/28/2017

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

Regenerative Brake-by-Wire System Development and Hardware-In-Loop Test for Autonomous Electrified Vehicle

2017-01-040103/28/2017

As the essential of future driver assistance system, brake-by-wire system is capable of performing autonomous intervention to enhance vehicle safety significantly. Regenerative braking is the most effective technology of improving energy consumption of electrified vehicle. A novel brake-by-wire system scheme with integrated functions of active braking and regenerative braking, is proposed in this paper. Four pressure-difference-limit valves are added to conventional four-channel brake structure to fulfill more precise pressure modulation. Four independent isolating valves are adopted to cut off connections between brake pedal and wheel cylinders. Two stroke simulators are equipped to imitate conventional brake pedal feel. The operation principles of newly developed system are analyzed minutely according to different working modes. High fidelity models of subsystems are built in commercial software MATLAB and AMESim respectively. The control strategies of brake force distribution and

Yuan, Ye, Zhang, Junzhi, Li, Yutong, Lv, Chen

Analysis of Energy Consumption on Typical Main Cylinder Booster Based Brake-by-Wire System

2016-01-195509/18/2016

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

Design and Performance Analysis of a Novel Regenerative Braking System for Electrified Passenger Vehicles

2016-01-043804/05/2016

A novel type of regenerative braking system for electric vehicles is proposed in this paper. Four pressure-difference-limit valves, two relief valves and two brake pedal simulators, are added to the layout of a conventional four-channel hydraulic modulator. The cooperation of relief valves and hydraulic pumps provides a stabilized high-pressure source. Pressure-difference-limit valves ensure that the pressure in each wheel cylinder can be modulated separately at a high precision. Besides, the functions of anti-lock braking system and electronic stability program are integrated in this regenerative braking system. The models of regenerative braking controller and vehicle dynamics are built in MATLAB/Simulink. Hydraulic brake model is built in AMESim through a parameterized and modularized method. Meanwhile, the control strategy of hydraulic brake modulation and brake force distribution are designed. Simulations are conducted via co-simulation interface between MATLAB and AMESim under

Yuan, Ye, Zhang, Junzhi, Lv, Chen, Li, Yutong

Development of New Electronically Controlled Hydraulic Unit for Various Applications

2016-01-166004/05/2016

The use of hybrid, fuel cell electric, and pure electric vehicles is on the increase as part of measures to help reduce exhaust gas emissions and to help resolve energy issues. These vehicles use regenerative-friction brake coordination technology, which requires a braking system that can accurately control the hydraulic brakes in response to small changes in regenerative braking. At the same time, the spread of collision avoidance support technology is progressing at a rapid pace along with a growing awareness of vehicle safety. This technology requires braking systems that can apply a large braking force in a short time. Although brake systems that have both accurate hydraulic control and large braking force have been developed in the past, simplification is required to promote further adoption. This paper describes the following three items: (1) an examination of the brake system functions that realize the regenerative-friction brake coordination and collision avoidance support

Okano, Takahiro, Sakai, Akira, Kamiya, Yusuke, Masuda, Yoshio, Yamaguchi, Tomoyuki

A Custom Integrated Circuit with On-chip Current-to-Digital Converters for Active Hydraulic Brake System

2016-01-009104/05/2016

This paper presents a custom integrated circuit (IC) on which circuit functions necessary for “Active Hydraulic Brake (AHB) system” are integrated, and its key component, “Current-to-Digital Converter” for solenoid current measurement. The AHB system, which realizes a seamless brake feeling for Antilock Brake System (ABS) and Regenerative Brake Cooperative Control of Hybrid Vehicle, and the custom IC are installed in the 4th-generation Prius released in 2015. In the AHB system, as linear solenoid valves are used for hydraulic brake pressure control, high-resolution and high-speed sensing of solenoid current with ripple components due to pulse width modulation (PWM) is one of the key technologies. The proposed current-to-digital converter directly samples the drain-source voltage of the sensing DMOS (double-diffused MOSFET) with an analog-to-digital (A/D) converter (ADC) on the IC, and digitizes it. The conversion characteristic is compensated for the DMOS onresistance variation by an

Watanabe, Hikaru, Segawa, Tsutomu, Okuhira, Takumi, Mima, Hiroki, Hoshikawa, Norishige

Development of an Electronically Controlled Brake System for Fuel-efficient Vehicles

2016-01-166404/05/2016

To solve various environmental problems, fuel-efficient vehicles that reduce CO2 emissions as well as exhaust gas emissions have been developed. In such vehicles, a regenerative brake is used to further reduce fuel consumption. Because the market size for such vehicles is expanding, a brake system is required that can be used in a wide range of vehicles extending from internal combustion engine vehicles (ICEVs) to electric vehicles (EVs). In addition, issues such as deceleration fluctuation and brake pedal fluctuation arise because the regenerative brake force is dependent on the vehicle speed. This paper presents a brake system configuration and its element technologies that can replace existing brake systems in different vehicles ranging from ICEVs to EVs. The proposed system can realize a regenerative cooperative brake not only by replacing the brake booster unit but also without replacing the modulator. The advantages of this system are the maximization of regenerative efficiency

Masuda, Yoshio, Yamasoe, Yosuke, Kuki, Yosuke, Okano, Takahiro, Uchida, Kiyoyuki

The New Era of Infotainment Systems

2015-36-023709/22/2015

This paper focuses on present information and technical details about the connectivity and new technologies in automotive infotainment systems, based on an independent research of the authors using public references. The evolution of the consumer electronics and the electronic products in all areas allowed new features in the automotive market. The changes in the microelectronics industries accelerate the release of new technologies. Transistor by transistor, the electronics industry is literally changing the world. Consider this: in 2015, there will be more than seven billion mobile devices in the world consuming and generating massive amounts of data. In addition to that, there are more than one billion transistors for each person in world due to the popularization of computers, smartphones and tablets. In this sense, vehicle’s development is following the same tendency, the leverage of new technology even in the entry level vehicles is a must. Product life cycles are compressing

de Souza, Rafael Navarenho, de Souza Fino, Leonardo Navarenho

New Slip Control System Considering Actuator Dynamics

2015-01-065604/14/2015

A new control strategy for wheel slip control, considering the complete dynamics of the electro-hydraulic brake (EHB) system, is developed and experimentally validated in Cranfield University's HiL system. The control system is based on closed loop shaping Youla-parameterization method. The plant model is linearized about the nominal operating point, a Youla parameter is defined for all stabilizing feedback controller and control performance is achieved by employing closed loop shaping technique. The stability and performance of the controller are investigated in frequency and time domain, and verified by experiments using real EHB smart actuator fitted into the HiL system with driver in the loop.

Soltani, Amir, Assadian, Francis

Research and Simulation of Electro-Hydraulic Braking System Based on Integrated Master Cylinder

2015-01-015904/14/2015

Analogous to a vacuum boosted system, Electro-Hydraulic Braking System (EHB) is free from engine vacuum and supplies a braking force proportional to driver input. The independence of engine vacuum makes it especially suitable to be used in electric vehicles (EVs) and hybrid electric vehicles (HEVs). As a key component of EHB, master cylinder is driven by the pump rather than the vacuum booster. Even if the pump fails, the cylinder can also build proper pressure. Meanwhile, in order to maintain the pedal feeling, a pedal stroke simulator is applied in the system. In this paper, aiming at decreasing the size and cost of master cylinder and providing an ideal pedal feeling without compromise of performance, a new integrated master cylinder of EHB system is designed including two parts: master cylinder and pedal stroke simulator. The key components of the integrated master cylinder are motor pump, solenoid valves and composite springs. A model of the EHB and other key components of the

Tan, Zhihui, Chen, Zhenfu, Pei, Xiaofei, Zhang, Jie, Guo, Xuexun

DEHB (Distributed Electro-hydraulic Braking System) Having a Holding Function

2015-01-001703/10/2015

Many types of brake by wire systems have been developed in past years, such as EMB (Electro-mechanical Brake) [1, 2], DEHB (Distributed Electro-hydraulic Braking System) [3] and EWB (Electric Wedge Brake) [4]. When the vehicle need braking in long period such as waiting for traffic light or downhill braking in those brake systems, the current will sustain very long time with very high level. This current will result in high temperature in motor, and will damage the power supplier. When a new DEHB is developing, a holding function is added in this DEHB. The holding function is self-energized when holding the brake, and automatic released after the brake. Advantageously, after activation of the holding function, the current delivered to the motor for braking is substantially decreased, especially, will be zero when the brake torque is not need to adjust. The holding function is fully mechanical, that means the holding function do not consume any power, and do not need to control it

Wang, Yufeng, Wang, Zhizhong, Yu, Liangyao, Song, Jian

Development & Integration of a Charge Sustaining Control Strategy for a Series-Parallel Plug-In Hybrid Electric Vehicle

2014-01-290510/13/2014

The Hybrid Electric Vehicle Team of Virginia Tech (HEVT) is participating in the 2012-2014 EcoCAR 2: Plugging in to the Future Advanced Vehicle Technology Competition series organized by Argonne National Lab (ANL), and sponsored by General Motors Corporation (GM) and the U.S. Department of Energy (DOE). The goals of the competition are to reduce well-to-wheel (WTW) petroleum energy consumption (PEU), WTW greenhouse gas (GHG) and criteria emissions while maintaining vehicle performance, consumer acceptability and safety. Following the EcoCAR 2 Vehicle Development Process (VDP), HEVT is designing, building, and refining an advanced technology vehicle over the course of the three year competition using a 2013 Chevrolet Malibu donated by GM as a base vehicle. The team selected a series-parallel Plug-In Hybrid Electric Vehicle (PHEV) with P2 (between engine and transmission) and P4 (rear axle) motors, a lithium-ion battery pack, an internal combustion engine, and an automatic transmission

Manning, P. Christopher, White, Eli, Marquez, Eduardo, Figueroa, Leonard, Shoults, Lucas, Nelson, Douglas

Vehicle Refinement and Testing of a Series-Parallel Plug-in Hybrid Electric Vehicle

2014-01-290410/13/2014

The Hybrid Electric Vehicle Team (HEVT) of Virginia Tech is ready to compete in the Year 3 Final Competition for EcoCAR 2: Plugging into the Future. The team is confident in the reliability of their vehicle, and expects to finish among the top schools at Final Competition. During Year 3, the team refined the vehicle while following the EcoCAR 2 Vehicle Development Process (VDP). Many refinements came about in Year 3 such as the implementation of a new rear subframe, the safety analysis of the high voltage (HV) bus, and the integration of Charge Sustaining (CS) control code. HEVT's vehicle architecture is an E85 Series-Parallel Plug-In Hybrid Electric Vehicle (PHEV), which has many strengths and weaknesses. The primary strength is the pure EV mode and Series mode, which extend the range of the vehicle and reduce Petroleum Energy Usage (PEU) and Greenhouse Gas (GHG) emissions. A primary weakness is the architectures complexity, which made it difficult for the team to truly reap the

Manning, P. Christopher, Marquez, Eduardo D., Figueroa, Leonard, Nelson, Douglas J., White, Eli Hampton, Shoults, Lucas Wayne

Design, Modeling and Simulation of a New Compact Electro-Hydraulic Brake System

2014-01-253509/28/2014

With the advantages of free from engine vacuum, wheel cylinder pressure decoupled from the brake pedal and can be regulated individually and precisely, the brake-by-wire system has a huge application potential in vehicles, especially in electric vehicles (EV) and hybrid electric vehicles (HEV). Electro-hydraulic Brake system is the first approach towards brake-by-wire technology. This paper proposed a new compact EHB, aiming at decreasing the size, volume and cost without compromise of performance. The main components of the proposed EHB are pedal simulator, motor pump, accumulator and eight solenoid valves. An authentic model of the EHB and other key components of the brake system were established based on the test data from the test bench. A control algorithm using Round-Robin scheduling was presented to regulate the fluid pressure. Some parameters of the components were discussed to research their effects on system performance. The effects of pressure regulation were examined in

Pan, Ning, Yu, Liangyao, Wang, Zhizhong, Ma, Liangxu, Song, Jian, Zhang, Yongsheng, Wei, Wenruo

Experimental Study of Interaction between Brake-Disc Surface Texture and Friction Material on Friction and Wear through Small-Scale Tests on Tribotester

2014-01-250209/28/2014

There are various processes for finishing the friction surfaces of a brake disc, which affect the braking effectiveness of a vehicle in the early stages of use in some cases. To examine the interaction between the disc surface texture, rotational direction, and friction material, a series of experiments on a tribotester using small-scale specimens was conducted. In a previous paper (2013-01-2056), the results from the first series of experiments, which involved of thirty disc surface textures and a less aggressive non-asbestos organic (NAO) friction material in on-brake-drag conditions combining constant speed and normal-load, was reported. Disc surfaces were finished by the following finishing processes in two rotational directions: turning under four cutting conditions, roller burnishing after turning, turning with a wiper insert, and grinding with two stones. Contact-pressure dependency of friction and wear was confirmed. Roller-burnished and wiper-turned discs exhibited different

Okamura, Toshikazu

Regenerative Braking Control Algorithm for an Electrified Vehicle Equipped with a By-Wire Brake System

2014-01-179104/01/2014

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

Development of a Control Strategy and HIL Validation of Electronic Braking System for Commercial Vehicle

2014-01-007604/01/2014

This article focuses on the research of control algorithm and control logic for the pneumatic EBS (Electronic Braking System) of commercial vehicle. An overall technical program was proposed which develops conventional braking and emergency braking for commercial vehicle EBS. According to the overall scheme, the methods of vehicle state estimation and driver's braking intention were determined, modeling and simulation for key components of commercial vehicle EBS were then carried out. This lead to the development of deceleration control, braking force distribution, brake assist and ABS control. Simulation models for key components of EBS and control strategy were validated through hardware-in-the-loop simulation tests. Simulation results show that the control strategy improves vehicle braking stability and vehicle active safety.

Han, Jongchol, Changfu, Zong, Weiqiang, Zhao

Vehicle Design and Implementation of a Series-Parallel Plug-in Hybrid Electric Vehicle

2013-01-249210/14/2013

The Hybrid Electric Vehicle Team (HEVT) of Virginia Tech has achieved the Year 2 goal of producing a 65% functional mule vehicle suitable for testing and refinement, while maintaining the series-parallel plug-in hybrid architecture developed during Year 1. Even so, further design and expert consultations necessitated an extensive redesign of the rear powertrain and front auxiliary systems packaging. The revised rear powertrain consists of the planned Rear Traction Motor (RTM), coupled to a single-speed transmission. New information, such as the dimensions of the high voltage (HV) air conditioning compressor and the P2 motor inverter, required the repackaging of the hybrid components in the engine bay. The P2 motor/generator was incorporated into the vehicle after spreading the engine and transmission to allow for the required space. This spreading of the components meant a redesign of the front powertrain mounts and integration of a torque damper as an interface with the combustion

Manning, Peter C., White, Eli, Caroncino, Kyle, Ashworth, Taylor, Kelly, Brian, Shoults, Lucas, Nelson, Douglas

Experimental Study of Effect of Brake-Disc Surface Texture on Friction and Wear through Small-Scale Tests on Tribotester

2013-01-205609/30/2013

The surface texture of a brake disc in some cases affects the braking effectiveness of a vehicle in the early stages of use. Brake discs usually turn in one rotational direction during their finishing process but are turn in two directions on a vehicle. This causes a difference in friction or wear between two wheels. Directional surface textures of brake discs finished by turning or roller burnishing may cause this interaction to become more severe than those finished by grinding. Full-scale tests using actual friction pairs are effective for estimating the total braking performance of a full vehicle or its corners. However, they are exposed to various factors and different brake-disc locations creating different friction and wear histories. The author, therefore, concluded that fundamental experiments using small-scale specimens are necessary to examine the details of the interaction between the disc surface texture, rotational direction, and friction material. In this paper, the

Okamura, Toshikazu

Prototype of Distributed Electro-Hydraulic Braking System and its Fail-Safe Control Strategy

2013-01-206609/30/2013

Prototype of a brake-by-wire (BBW) system named Distributed Electro-hydraulic Braking System (DEHB) has been developed. As a BBW system, DEHB is suitable to be used in electric vehicles (EV) and hybrid electric vehicles (HEV). Comparing to the ‘dry’ type distributed BBW systems such as Electro-mechanical Braking System (EMB) or Electric Wedge Brake (EWB), the ‘wet’ feature of DEHB brings benefits to system cost, installation, performance and reliability. In this paper, prototype of the DEHB was described. Based on its ‘wet’ feature, a new fail-safe control for DEHB was proposed. Two types of DEHB architectures that can perform the proposed fail-safe control were described. Superiority of the proposed fail-safe control and architectures for DEHB were examined and verified through simulations and HIL experiments, which helps DEHB to reach a high level of safety and reliability with reduced cost on electro/electronic redundancy.

Wang, Zhizhong, Yu, Liangyao, Wang, Yufeng, You, Changxi, Ma, Liangxu, Song, Jian

Application of Electric Servo Brake System to Plug-In Hybrid Vehicle

2013-01-069704/08/2013

An electric servo brake system applied for use on electric vehicles was applied for use on plug-in hybrid vehicles in order to achieve fuel-savings together with good brake feel and enhanced operability for plug-in hybrid vehicles. The electric servo brake system is made up of highly accurate braking pressure control that functions cooperatively with regenerative brakes together with a structure in which pedal force is not influenced by braking pressure control. The configuration of these components enabled good braking feel even when the power train was being switched from one drive mode to another. Automated pressurization functions that are intended for plug-in hybrid vehicles and that operate with electric servo brake systems were also developed. These developed functions include stall cooperative control that functions cooperatively with the power train, regenerative coordinate adaptive cruise control, and hill-start assist. The application of these automated pressurization

Ohkubo, Naoto, Matsushita, Satoshi, Ueno, Masayuki, Akamine, Kohei, Hatano, Kunimichi

A Unified Framework of Adaptive Cruise Control for Speed Limit Follower and Curve Speed Control Function

2013-01-061804/08/2013

Today many vehicles are being developed with advanced computing and sensing technologies. These new technologies have contributed in enhancing driving safety and convenience. As an example, the Adaptive Cruise Control (ACC) can automatically adjust the vehicle speed to driver's set speed and maintain the driver-requested headway distance to the lead vehicle. In this paper, we further consider the automatic control of speed according to the road attributes, e.g., the speed limit and curve of the road. Two new features, ‘speed limit follower’ and ‘curve speed control’ algorithms, are proposed in this paper. These new features communicate with the conventional ACC system and control the vehicle speed while traveling across different curved roads and speed limit zones. These new features were developed as an independent function, so they can be integrated with any other existing ACC systems. The key enabler for these features is sensing the speed limit and the curvature of upcoming roads

Lee, Jin-Woo, Prabhuswamy, Shilpa

Analysis of Input Power, Energy Availability, and Efficiency during Deceleration for X-EV Vehicles

2013-01-147304/08/2013

The recovery of braking energy through regenerative braking is a key enabler for the improved efficiency of Hybrid Electric Vehicles, Plug-in Hybrid Electric, and Battery Electric Vehicles (HEV, PHEV, BEV). However, this energy is often treated in a simplified fashion, frequently using an overall regeneration efficiency term, ξrg [1], which is then applied to the total available braking energy of a given drive-cycle. In addition to the ability to recapture braking energy typically lost during vehicle deceleration, hybrid and plug-in hybrid vehicles also allow for reduced or zero engine fueling during vehicle decelerations. While regenerative braking is often discussed as an enabler for improved fuel economy, reduced fueling is also an important component of a hybrid vehicle's ability to improve overall fuel economy. Much like energy captured though regenerative braking, engine fueling during deceleration is also often treated using an estimated deceleration fueling rate which is then

Rask, Eric, Santini, Danilo, Lohse-Busch, Henning

Mass Estimation and Axle Load Distribution Algorithm for EBS of Large Bus

2013-01-041704/08/2013

The paper describes an algorithm, which estimates the mass of large buses and axle load distribution using pedal position, wheel speed and the wheel cylinder pressure sensors. This algorithm is allowed to achieve the purpose without additional sensors by using the rotational speed sensors from ABS system and air pressure sensors in brake cylinders form ESP system. The axle load distribution algorithm mainly consists of three steps. Firstly, deceleration of the bus is estimated and then the mass of the bus is estimated. After that, the position of the mass centre is estimated. Taking account of the tire nonlinear characteristics under longitudinal forces and vertical forces, mass estimation, deceleration and the position of the mass centre of buses is corrected by the coefficient, which is determined by the wheel cylinder pressure, the wheel speed and mass estimation. When the deceleration, mass of the large bus and the mass center of the whole bus are completely estimated, load of each

Nie, Zhigen, Zong, Changfu, Wan, Ying

Development of the Electrically-Controlled Regenerative Braking System for Electrified Passenger Vehicle

2013-01-146304/08/2013

As one of the key technologies of electrified vehicles, regenerative braking offers the capability of fuel saving by converting the kinetic energy of the moving vehicle into electric energy during deceleration. To coordinate the regenerative brake and friction brake, improving regeneration efficiency and guaranteeing brake performance and brake safety, development of special brake systems for electrified vehicles is needed. This paper presents a new type of electrically-controlled regenerative braking system (EABS) that has been developed for electrified passenger vehicles, which has the potential to be brought into production in China. By utilizing as much as possible mature components, integrating cooperative regeneration with ABS/TCS functions, EABS can achieve high regeneration efficiency and brake safety while providing system reliability, low development cost and development risk. This article describes the layout of the newly developed regenerative braking system. The operation

Zhang, Junzhi, Lv, Chen, Yue, Xiaowei, Qiu, Mingzhe, Gou, Jinfang, He, Chengkun

Braking for safety

13OFHD0404_0204/04/2013

Researchers developed a simplified ABS/EBS ECU test bench to research the brake force control function of the EBS system using HIL simulation technology. As more sensors are installed into vehicles and equipment, ABS is no longer the single antilock braking system with original functions, but with more features, such as EBD (electronic brakeforce distribution), ASR (anti-slip regulation), PBA (panic brake assist), CBC (cornering brake control), HAC (hill-start assist control), et al. For modern vehicles, safety is quite dependent on the performance of the ABS electronic control unit (ECU). ABS has been through a variety of iterations, and the electronically controlled brake system (EBS) is one of them.

Integrated HIL Test and Development System for Pneumatic ABS/EBS ECU of Commercial Vehicles

2012-01-203109/24/2012

The quality of the brake system is a significant safety factor in commercial vehicles on the roads. With the development of automobile technology, the single function ABS system didn't meet active safety requirements of the user. The Electronically Controlled Brake System (EBS) system will replace the ABS system to become the standard safety equipment of commercial vehicles in the near future. EBS can be said an enhanced ABS system, it contains load sensor, brake valve sensor and pressure sensor of chamber, etc, and it is more advantages than ABS. This paper describes a flexible integrated test bench for ABS/EBS Electronic Control Unit (ECU) based on Hardware-In-the-Loop (HIL) simulation technique. It consists of most commercial vehicle pneumatic braking system components (from brake pedal valve, brake caliper to brake chambers), and uses the dSPACE real-time simulation system to communicate to the hardware I/O interface. A precise fifteen degrees of freedom (DOF) commercial vehicle

Weiqiang, Zhao, Zong, Changfu, Zheng, Hongyu, Wang, Huaji, Yang, Shengnan

A New Approach to the Electronic Wedge Brake

2012-01-180109/17/2012

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

Design and Development Process of a Parallel-Through-The-Road Plug-In Hybrid Electric Vehicle

2012-01-176909/10/2012

The CSULA EcoCAR 2 Team is participating in the EcoCAR 2 Advanced Vehicle Technology Competition Series sponsored by General Motors Corporation, the U.S. Department of Energy, Natural Resources Canada, and Argonne National Lab. This report documents the design process of the CSULA Hybrid Electric Vehicle. The Vehicle Design Process, Powertrain Configuration, Control Development Process, Control System Architecture, Control Algorithm and Strategy, Packaging and Integration, and Energy Storage System are explained. Ultimately, anE85 Parallel Through-The-Road Plug-in Hybrid Electric Vehicle (PTTR) was chosen as the vehicle architecture that could accomplish competition requirements and team goals.

Reid, Christopher, Blekhman, David, Banales, Guadalupe, Fang, Ren, Liu, Phat

An Innovative 4WD PHEV Utilizing a Series-Parallel Multiple-Regime Architecture

2012-01-176409/10/2012

The focus of this paper is the design and implementation of a series-parallel multiple-regime plug-in hybrid electric vehicle (PHEV) using a 2013 Chevrolet Malibu as a platform. The University of Victoria EcoCAR team used a 3-year vehicle development process (VDP) modeled after those used by Tier 1 automotive manufacturers, and maintained by the rules of EcoCAR 2: Plugging into the Future. Intensive research was conducted to determine the ideal architecture selection based on overall greenhouse gas (GHG) emissions, criteria air contaminant (CAC) emissions, fuel economy, petroleum use, and vehicle performance. As a result, a series-parallel design was pursued, using a high power rear traction motor and large BAS electric machine tied to an E85 compatible 4-cylinder internal combustion engine (ICE). This architecture platform provides for multiple regimes of operation including electric only operation provided by the 14.8 kWh lithium ion battery. The architecture is very flexible in

Kaban, Stefan, Nelford, Jason Clancy, Dong, Zuomin, Dong, Jian, Killy, David, Prescott, Daniel, Crawford, Curran

Development of General Motors' eAssist Powertrain

2012-01-103904/16/2012

General Motors' (GM) eAssist powertrain builds upon the knowledge and experience gained from GM's first generation 36Volt Belt-Alternator-Starter (BAS) system introduced on the Saturn VUE Green Line in 2006. Extensive architectural trade studies were conducted to define the eAssist system. The resulting architecture delivers approximately three times the peak electric boost and regenerative braking capability of 36V BAS. Key elements include a water-cooled induction motor/generator (MG), an accessory drive with a coupled dual tensioner system, air cooled power electronics integrated with a 115V lithium-ion battery pack, a direct-injection 2.4 liter 4-cylinder gasoline engine, and a modified 6-speed automatic transmission. The torque-based control system of the eAssist powertrain was designed to be fully integrated with GM's corporate common electrical and controls architectures, enabling the potential for broad application across GM's global product portfolio.

Hawkins, Shawn, Billotto, Fred, Cottrell, Daniel, Houtman, Alan, Poulos, Stephen, Rademacher, Roger, Van Maanen, Keith, Wilson, Daryl

Integrated Control of Dynamometer Using LabVIEW Platform - Hardware

2011-36-007110/04/2011

The paper addresses the development of an electromagnetic brake control and data capture of torque and rotation, using a graphical interface implemented in LabVIEW for evaluating the performance of internal combustion engines. To control the electromagnetic brake is used like a SMPS Buck, and programming interface developed in LabView is responsible for generating the pulses of voltage that feeds the brake and the data capture system. This project started with the need for improved equipment control and data acquisition dynamometers, eddy-current, installed at the Automotive Laboratory, Instituto Federal de Santa Catarina (IFSC). In the system of control and data acquisition parameters can be added as temperatures, pressures etc., further improving the precision of torque and power these devices.

Luca, Andrei Moro de, Victorette, Milena, Vandresen, Marcelo, Alves Neto, José de Pinho

Brake Design and Safety, Third Edition

R-39810/04/2011

The objectives of this third edition of an SAE classic title are to provide readers with the basic theoretical fundamentals and analytical tools necessary to design braking systems for passenger vehicles and trucks that comply with safety standards, minimize consumer complaints, and perform safely and efficiently before and while electronic brake controls become active. This book, written for students, engineers, forensic experts, and brake technicians, provides readers with theoretical knowledge of braking physics, and offers numerous illustrations and equations that make the information easy to understand and apply. New to this edition are expanded chapters on: • Thermal analysis of automotive brakes • Analysis of hydraulic brake systems • Single vehicle braking dynamics

Limpert, Rudolf

Effect of Directional Surface Finish of Brake Discs on Friction Behavior During Running-in

2011-01-238209/18/2011

This paper focuses on the interaction in friction behavior between the surface texture of brake discs, rotational directions in braking operations and metal-cutting process, and friction materials with different degrees of aggressiveness. A factorial experiment for front brake discs was conducted by combining eight discs with directional surface finishes, two rotational directions, and two NAO friction materials on a brake dynamometer. The author analyzed several test results, such as the friction coefficients, disc wear, roughness, and the correlation between them. An assumed mechanism describing the friction behavior is discussed using the experimental results and by introducing the contribution of the aggressiveness and adhesiveness to the friction and confirmed by the test results.

Okamura, Toshikazu

Development of an Electrically-Driven Intelligent Brake Unit

2011-01-057204/12/2011

An electrically-driven, intelligent brake unit has been developed, to be combined with a regenerative braking system in electric vehicles (EVs) and hybrid electric vehicles (HEVs) which went into production in 2010 - 11. The brake pedal force is assisted by an electrically driven motor, without using vacuum pressure, unlike conventional braking systems. The actuator can be implemented to coordinate with a regenerative braking system, and to have adjustable pedal feel through use of a unique pressure-generating mechanism and a pedal-force compensator. In this paper, we describe features of the actuator mechanism and performance test results

Ohtani, Yukio, Innami, Toshiyuki, Obata, Takuya, Yamaguchi, Tohma, Kimura, Tetsuo, Oshima, Toshiaki

Estimation of Vehicle Roll Angle and Side Slip for Crash Sensing

2010-01-052904/12/2010

Estimation of vehicle roll angle, lateral velocity and side slip angle for the purpose of crash sensing is considered. Only roll rate sensor and the sensors readily available in vehicles equipped with ESC (Electronic Stability Control) systems are used in the estimation process. The algorithms are based on kinematic relationships, thus avoiding dependence on vehicle and tire models, which minimizes tuning efforts and sensitivity to parameter variations. The estimate of roll angle is obtained by blending two preliminary estimates, each valid in different conditions, in such a manner that the final estimate continuously favors the more accurate one. The roll angle estimate is used to compensate the gravity component in measured lateral acceleration due to vehicle roll or road bank angle. This facilitates estimation of lateral velocity and side slip angle from fundamental kinematic relationships involving the gravity-compensated lateral acceleration, yaw rate and longitudinal velocity

Hac, Aleksander, Nichols, David, Sygnarowicz, Daniel

Brake Response Time Measurement for a HIL Vehicle Dynamics Simulator

2010-01-007904/12/2010

Vehicle dynamics simulation with Hardware In the Loop (HIL) has been demonstrated to reduce development and validation time for dynamic control systems. For dynamic control systems such as Anti-lock Braking System (ABS) and Electronic Stability Control (ESC), an accurate vehicle dynamics performance simulation system requires the Electronic Brake Control Module (EBCM) coupled with the vehicles brake system hardware. This kind of HIL simulation-specific software tool can further increase efficiency by means of automation and optimization of the development and validation process. This paper presents a method for HIL vehicle dynamics simulator optimization through Brake Response Time (BRT) correlation. The paper discusses the differences between the physical vehicle and the HIL vehicle dynamics simulator. The differences between the physical and virtual systems are used as factors in the development of a Design Of Experiment (DOE) quantifying HIL simulator performance. Finally, the DOE

Wilkinson, John, Mousseau, Cedric W., Klingler, Thomas

Design, Modeling and Hardware Implementation of a Next Generation Extended Range Electric Vehicle

2010-01-083004/12/2010

Advances in battery and hybrid powertrain technology have significantly expanded the automotive design space. In this work, the design process of a new extended range electric vehicle (E-REV) is presented, following the industry standard vehicle development process (VDP). To effectively achieve the design targets, the team developed the project following a model-based design (MBD) approach which is similar to what is used in industrial practice. The design process started from a vehicle technical specification, which defines the required vehicle performance characteristics. Then models were built to exam various design options against the design targets. Improved vehicle performance was demonstrated through model-in-loop (MIL), software-in-loop (SIL) and hardware-in-loop (HIL) simulations. The designed vehicle uses a 2009 Saturn VUE as a baseline platform and incorporates a new powertrain which includes a GM 2-Mode transmission, a GM E85 flex-fuel engine, a rear traction motor and a

Zhou, Leon, Wise, Jeremy, Bowman, Shaun, Crawford, Curran, Dong, Zuomin

Development of an Auxiliary Pressurized Hybrid Brake System for a Parallel Hybrid Electric Commercial Van

2009-01-287610/06/2009

Efficient use of oil resources has become the number one priority throughout the world. Vehicles, operating with alternative fuels like solar or hydrogen energy are still in the development phase. In this transition period, automotive companies are trying to produce more efficient road vehicles to reduce the negative impacts of the internal combustion engine. Advances in high-efficiency electrical machines (EM), high-specific energy/power units, lower-cost power electronics and embedded systems have promoted the use of EM solely and/or along with the internal combustion engine (ICE) to develop pollution-free vehicles. Due to the high cost of the energy storage units for a pure electric drive the current trend is towards the practice of hybrid electric vehicle (HEVs). This paper presents the design of a novel brake system, namely Auxiliary Pressurized Hybrid Brake System (APHBS), which enables energy recovery and a safe transition from regenerative brake (RB) to hydraulic brake (HB

Altidemir, Esen, Hartavi, Ahu Ece, Güvenç, Levent, Göktan, Ali, Yildirim, Murat

Braking System Definitions—Truck and Bus

J2627_200908-TEST-REC (Historical)08/03/2009

This SAE Recommended Practice identifies and defines terms specifically related to truck and bus braking systems including Antilock Brake Systems (ABS) and Electronically Controlled Braking Systems (ECBS).

Truck and Bus Brake Systems Committee

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