Liang Yao

Integrative braking control system for electric vehicles

For Electric Vehicle (EV), energy saving and endurance mileage prolonging are very important. Regenerative braking techniques are key parts of electric techniques for saving energy. The traditional braking system must be updated to adapt the condition that the friction braking force is coexisting with the motor regenerative braking force. For the integrative braking control system it is so important to keep the traditional braking performance while recovering braking energy and fully exert the capability of the motor. In this paper, a new integrative braking control system will be studied. The simulation results based on the ADVISOR and the HIL test bench validate the effects of the system, such as energy recovering and braking performance.

Integrative control strategy of regenerative and hydraulic braking for hybrid electric car

Since electric braking involvement, the braking system of an EV, HEV and FCV becomes much more complex than conventional mechanical alone braking system. The target in this hybrid braking system is to recover the braking energy as much as possible and meanwhile maintain a good braking performance for vehicle safety. For this purpose, the control of this braking system is very crucial. In this paper, a integrative braking control strategy has been developed and simulation model has been established, by which the braking performance has been validated, that includes energy recovering, braking feel and braking safety etc..

Study of a Method for Improving the Anti-Lock Brake System of Electric Vehicle

The Anti-lock Braking System (ABS) of Electric Vehicle (EV) is improved in this paper. Based on the research of system structure and motor, a new method is proposed to adjust the threshold and coordinate the motor braking force with the friction braking force. So the traditional threshold control algorithm of ABS is improved for the EV. The simulation results based on the MATLAB/Simulink model indicate that the improved ABS can keep the wheels in the stability region and decrease the motor regenerative braking force as soon as possible. The balance between brake safety and energy recovery is achieved through this method.

Coordination Control for RBS and ABS

This paper puts forward 3 new coordination control states based on the analysis of the control logic of pure hydraulic ABS during braking .In order to reduce the regenerative brake force, we make the logic conversion according to the present coordination control method and the hydraulic brake force can compensate the regenerative brake force. The simulation results show that the 3 states proposed in this paper combine the present coordination control method and optimize the coordination control of the regenerative brake force and the hydraulic brake force under the anti-lock braking condition.

Integrative Control of Regenerative Braking System and Anti-Lock Braking System

For Electric Vehicle (EV), energy saving and endurance mileage prolonging are very important. Regenerative Braking System (RBS) is a key point in this respect. At the same time, braking safety is a rigid demand of EV. In this respect, the Anti-lock Braking System (ABS) has an excellent performance. As a result, the integration of RBS and ABS plays an important role in the development of the EV control. In this paper, a dynamic adaptive threshold theory decides when RBS should exist will be studied, and when the states of vehicle reach the adaptive threshold, a sliding mode control method will be used to meet the total braking force and the system will reduce the motor braking force. Before slip rate of vehicle reaches the ABS threshold, the regenerative braking force will be reduced to 0. The braking safety will be improved in this way.

The Design of Regenerative Braking System with a Pedal Emulator

According to the regenerative braking system(RBS) with a pedal emulator as well as the control strategy. Design a hardware test platform of power regenerative system and the scheme of software experiment. Aim at the control strategy, braking safety and braking feeling of RBS with a braking pedal emulator is confirmed via hardware in loop (HIL) test. A high regenerative rate is obtained. From the result of simulation, the pedal force line from RBS with a pedal emulator is between the envelope curve of the pedal force from conventional vehicle. Actual wheel cylinder pressure can follow the change of target pressure very well. The regenerative braking rate reaches 53%.

Design of Brake Pedal Stroke Simulator for Hybrid Electric Car

A brake pedal stroke simulator is a key component of realizing a Regenerative Braking System. It provides a good pedal feeling to a driver, improves energy recovery and ensures braking security. This paper presents the hardware solution of the braking control system, the structure and key design parameters of a brake pedal stroke simulator. Through simulation, the energy recover rate and brake pedal feeling of drivers can be improved. The simulator can be used to realize the regenerative braking system in hybrid or electric vehicles.

Regenerative Braking System Pressure Control Calculation Based on ABS Hydraulic Model

The main objective of this work is to present a methodology for development of regenerative braking system hydraulic model that can be used to estimate the master cylinder pressure, master cylinder travel position, normal open valve fluid flow, normal open valve cross-sectional area, normal close valve fluid flow, normal close valve cross-sectional area, accumulator fluid flow and brake caliper fluid flow. According to the above hydraulic model calculation, the cooperation between regenerative braking system generator and ABS hydraulic braking control will be smooth and the arbitration strategy can be designed. Through the simple hydraulic model, the entire brake circuit of ABS can be derived easily.

Vehicle stability control algorithm based on optimal fuzzy theory

As a new active safety technology, Vehicle Stability Control (VSC) system can maintain the vehicle stability by dominating the yaw moment effectively under extreme driving conditions. This paper presents a novel VSC strategy devoted to prevent vehicles from spinning and drifting out, which is based on the Linear Quadratic Regulator (LQR) and the fuzzy control theory. The response of the vehicle can follow the ideal output of the 2-DOF reference model through controlling the yaw rate and side slip angle. The performance of the proposed algorithm is evaluated under various emergency maneuvers and road conditions. The simulation results indicate that the proposed system can significantly improve vehicle lateral stability for active safety, which has strong adaptability and robustness.

Research on the Braking System Control Strategy of Hybrid Electronic Bus

As one of the key technologies of Hybrid Electronic Bus, regenerative braking technology can recover energy without changing the traditional bus braking habit. This is of vital importance in the research of regenerative braking system. Because the braking force distribution relationship between the front and rear axle of the vehicle has a remarkable influence in the braking stability,especially adding the regenerative braking force, the influence is even larger. So the anti-lock braking control strategy for the hybrid electronic vehicle is updated in this paper according to the condition of regenerative braking. The anti-lock braking control and regenerative braking control were integrated in one ECU (Electronic Control Unit) of braking control system, collecting signals of wheel rotate speed, vehicle speed, SOC and brake pedal position by CAN bus. And the output control commands are sent to the execution unit of anti-lock braking system and regenerative braking system. The effectiveness of energy regeneration and the braking stability of this strategy are tested on the off-line simulation platform.