MPC-based compensation control system for the yaw stability of distributed drive electric vehicle

In extreme weather condition, the electric vehicle yaw stability control accuracy is low. A new yaw stability control system for electric vehicle driven by hub motor is designed to simplify the hardware system design and improve the system response speed. The driving control module is used to analyse the driving state parameters of the vehicle and calculate the four-wheel moment to control the yaw stability of the vehicle, which is transmitted to the battery control module. The UDU in the control module adjusts the motor speed and power output in real time according to the vehicle power demand after analyzing the vehicle driving state data. In the software part of the system, the vehicle dynamic model is built and yaw stability control strategy is used to complete the vehicle yaw stability control. The experimental results show three important parameters of the designed system for evaluating the manoeuvrability tend to ideal values under the control of the system, in which yaw angular velocity is controlled from 0.277 rads to 0.286 rads and the difference between them is 0.002 and 0.011. The yaw stability control accuracy is also high.

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Effect of Inner and Outer Wheels Driving Force Control on Small Electric Vehicle

International Journal of Automotive and Mechanical Engineering ◽

10.15282/ijame.17.4.2020.02.0622 ◽

2020 ◽

Vol 17 (4) ◽

pp. 8246-8254

Author(s):

K. Shibazaki ◽

H. Nozaki

Keyword(s):

Control System ◽

Angular Velocity ◽

Electric Vehicle ◽

Force Constant ◽

Force Control ◽

Driving Force ◽

Vehicle Control ◽

Steering Angle ◽

Force Control System ◽

The Difference

In this study, in order to improve steering stability during turning, we devised an inner and outer wheel driving force control system that is based on the steering angle and steering angular velocity, and verified its effectiveness via running tests. In the driving force control system based on steering angle, the inner wheel driving force is weakened in proportion to the steering angle during a turn, and the difference in driving force is applied to the inner and outer wheels by strengthening the outer wheel driving force. In the driving force control (based on steering angular velocity), the value obtained by multiplying the driving force constant and the steering angular velocity, that differentiates the driver steering input during turning output as the driving force of the inner and outer wheels. By controlling the driving force of the inner and outer wheels, it reduces the maximum steering angle by 40 deg and it became possible to improve the cornering marginal performance and improve the steering stability at the J-turn. In the pylon slalom it reduces the maximum steering angle by 45 deg and it became possible to improve the responsiveness of the vehicle. Control by steering angle is effective during steady turning, while control by steering angular velocity is effective during sharp turning. The inner and outer wheel driving force control are expected to further improve steering stability.

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