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Integrated Regenerative Braking System and Anti-Lock Braking System for Hybrid Electric Vehicles & Battery Electric Vehicles

Ford Motor Company-Yixin Yao, Yanan Zhao, Mark Yamazaki
  • Technical Paper
  • 2020-01-0846
To be published on 2020-04-14 by SAE International in United States
This paper describes development of an integrated regenerative braking system and anti-lock brake system (ABS) control during an ABS event for hybrid and electric vehicles with drivelines containing a single electric motor connected to the axle shaft through an open differential. The control objectives are to recuperate the maximum amount of kinetic energy during an ABS event, and to provide no degraded anti-lock control behavior as seen in vehicles with regenerative braking disabled. The paper first presents a detailed control system analysis to reveal the inherent property of non-zero regenerative braking torque control during ABS event and explain the reason why regenerative braking torque can increase the wheel slip during ABS event with existing regenerative braking control strategies. Then, the regenerative brake control problem during ABS events is formulated with a unified control system architecture where the regenerative braking torque is coordinated with the friction braking torque of ABS system. An integrated closed loop based wheel slip control including both regenerative braking control loop and friction braking control loop during ABS event, referred to as…
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Test Bench for Static Transmission Error Evaluation in Gears

Politecnico di Torino-Carlo Rosso
Politecnico di Torino / GeDy TrAss-Tommaso Maggi, Claudio Marcellini, Fabio Bruzzone
  • Technical Paper
  • 2020-01-1324
To be published on 2020-04-14 by SAE International in United States
In this paper a test bench for measuring the Static Transmission Error of two mating gears is presented and a comparison with the results obtained with the commercial software GeDy TrAss is shown. Static Transmission Error is considered as the main source of overloads and Noise, Vibration and Harshness issues in mechanical transmissions. It is defined as the difference between the theoretical angular position of two gears under load in quasi-static conditions and the real one. This parameter strictly depends on the applied torque and the tooth macro and micro-geometry. The test bench illustrated in this work is designed to evaluate the actual Static Transmission Error of two gears under load in quasi-static conditions. In particular, this testbed can be divided in two macro elements: the first one is the mechanism composed by weights and pulleys that generates a driving and a braking torque up to 500 Nm. The second element is composed by two structures called “supports”: one fixed to the floor and the other movable in order to be as much as possible…
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Effect of Stator Surface Area on Braking Torque and Wall Heat Dissipation of Magnetorheological Fluid Retarder

Suizhou-WUT Industry Research Institute-Gangfeng Tan
Wuhan University of Technology-ZhiQiang Liu, Zhongpeng Tian, Mi Zhou, Philip Agyeman, Justice Frimpong
  • Technical Paper
  • 2020-01-0937
To be published on 2020-04-14 by SAE International in United States
Magnetorheological fluid (MRF) is used as the transmission medium of the hydraulic retarder. The rheological properties are regulated by changing the magnetic field to achieve accurate control of the retarder's braking torque. Under the action of the external magnetic field, the flow structure and performance of the MRF retarder will be changed in a short time. The apparent viscosity coefficient increases by several orders of magnitude, the fluidity deteriorates and the heat generated by the brake cannot be transferred through the liquid circulation, which will affect the braking torque of the retarder. Changing the surface area of the stator also has an influence on the braking torque of the retarder and the wall heat dissipation. In this study, the relationship between the braking torque of the MRF retarder and the stator surface area of the retarder was analyzed. In addition, phase change materials were used to directly dissipate heat on the retarder surface to improve the heat dissipation rate of retarder and improve the stability of the retarder's braking torque. In order to study the…
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Fault-Tolerant Control of Regenerative Braking System on In-Wheel Motors Driven Electric Vehicles

Xiaohui Hou
Tsinghua University-Yuan Ji, Junzhi Zhang, Weilong Liu
  • Technical Paper
  • 2020-01-0994
To be published on 2020-04-14 by SAE International in United States
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 variables. Therefore, typical nonlinear controller design methods based on Lyapunov theory cannot be applied directly. In this paper, the problem is settled down by transferring the input matrix whose dimension is larger…
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Water Injection System Application in a Mild Hybrid Powertrain

Chalmers University of Technology-Jayesh Khatri, Lucien Koopmans
  • Technical Paper
  • 2020-01-0798
To be published on 2020-04-14 by SAE International in United States
The potential of 48V Mild Hybrid is promising in meeting the present and future CO2 legislations. There are various system layouts for 48V hybrid system including P0, P1, P2. In this paper, P2 architecture is used to investigate the effects of water injection benefits in a mild hybrid system. Electrification of the conventional powertrain uses the benefits of an electric drive in the low load-low speed region where the conventional SI engine is least efficient and as the load demand increases the IC Engine is used in its more efficient operating region.Engine downsizing and forced induction trend is popular in the hybrid system architecture. However, the engine efficiency is limited by combustion knocking at higher loads thus ignition retard is used to avoid knocking and fuel enrichment becomes must to operate the engine at MBT (Maximum Brake Torque) timing; in turn neutralizing the benefits of fuel savings by electrification. Water injection suppresses engine knocking and enables operating at stoichiometric air-fuel ratio. In addition to that, the injection of water reduces flame temperature, giving room to…
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Research on the Performance of Magnetorheological Fluid Auxiliary Braking Devices Thermal Management System Based on Flat Plate Heat Pipes

KNUST-Micheal Sackey
Kumasi Technical University-Prince Owusu-Ansah
  • Technical Paper
  • 2020-01-0894
To be published on 2020-04-14 by SAE International in United States
To prevent braking recession, heavy commercial vehicles are often equipped with fluid auxiliary braking devices, such as hydraulic retarder. Hydraulic retarder can convert the vehicle’s kinetic energy to the fluid heat energy, which can enormously alleviate the main brake’s workload. The traditional hydraulic retarder can provide enough braking torque but has a delay during the braking. In this paper, a new type of magnetorheological fluid (MR fluid) hydraulic retarder is introduced by replacing the traditional fluid with magnetorheological fluid because of its linear braking torque and quick response. By changing the magnetic field intensity, it is easier to control the braking torque than the traditional hydraulic retarder. The rise of magnetorheological fluid temperature during the braking period will reduce the hydraulic retarder’s performance. To research, the influence of temperature on the retarder’s braking torque, the model of MR fluid is established through the theory of one-dimensional flow theory of hydraulic retarders. In this paper, the braking torque of retarder is calculated based on the Bingham model. In order to get a higher performance, a cooling…
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Research on Thermal Management of Magnetorheological Fluid Retarder Based on Phase Change Principle

Wuhan University of Technology-Jiakang Quan, Bo Huang
  • Technical Paper
  • 2020-01-0948
To be published on 2020-04-14 by SAE International in United States
In order to avoid the braking recession on heavy commercial vehicles caused by the long-distance continuous braking of the main brake, the hydraulic retarder is widely used as an important brake auxiliary device in various heavy commercial vehicles to improve the vehicle safety. However, the hydraulic retarder not only has the advantages of large braking torque and good stability, but also has the disadvantages of poor retarding ability at low rotating speed, braking lag and difficulty in accurately controlling the braking torque. This paper introduces a new type of hydraulic retarder. The new retarder replaces the oil in the retarder with magnetorheological fluid and applies a magnetic field in the retarder arrangement space, so that slows down the vehicle by using the rheological properties of the magnetorheological fluid under the magnetic field. The magnetorheological fluid hydraulic retarder (MRFHR) generates a large amount of heat during working which not only decreases the braking performance, but also causes the structure to be damaged, and even risks the safety of the driver and the vehicle. This paper studies…
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Research on Control Target of Truck Platoon Based on Maximizing Fuel Saving Rate

SAE International Journal of Vehicle Dynamics, Stability, and NVH

Jilin University, China-Hongyu Zheng, Jianjun Wu, Kaiqiang Pan, Wanjia Meng, Rui Li
  • Journal Article
  • 10-04-02-0010
Published 2020-02-04 by SAE International in United States
In view of the inability of traditional constant spacing policy to maximize the fuel saving rate of the truck platoon when choosing the smaller desired vehicle spacing as the control target, a new control strategy is proposed in this article. This strategy dramatically reduces the fuel consumption of the truck platoon from the start to the formation of a stable platoon, thus greatly increasing the fuel saving rate of the platoon. To prove the effectiveness of the strategy, this article carried out the longitudinal dynamics modeling of the truck and the modeling of the fuel consumption model of engine first. Longitudinal dynamics modeling establishes the dynamic equations for truck braking and nonbraking. The fuel consumption model of engine is built using a three-dimensional map. Second, the design of the controller is described. The controller calculates the desired acceleration of the following vehicle based on the speed error and the following distance error. The longitudinal dynamic equation of the truck is used to derive the desired engine torque or the desired braking torque of the following…
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Information on Brake-By-Wire (BBW) Brake Control Systems

A-5A Wheels, Brakes and Skid Controls Committee
  • Aerospace Standard
  • AIR5372A
  • Current
Published 2019-10-25 by SAE International in United States
This SAE Aerospace Information Report (AIR) describes the design approaches used for current applications of aircraft Brake-by-Wire (BBW) control systems. The document also discusses the experience gained during service, and covers system, ergonomic, hardware, and development aspects. The document includes the lessons that have been learned during application of the technology. Although there are a variety of approaches that have been used in the design of BBW systems, the main focus of this document is on the current state of the art systems.
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Parking Brake Drawbar Pull Test Procedure - Truck and Bus

Truck and Bus Brake Systems Committee
  • Ground Vehicle Standard
  • J1729_201910
  • Current
Published 2019-10-17 by SAE International in United States
This SAE Recommended Practice provides a test method and instructions for measuring performance of parking brakes on air- or hydraulic-braked vehicles equipped with in-wheel or drive-line parking brakes. This procedure applies to truck-tractors, trailers, trucks, and buses.
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