ESP and EPS combined system for vehicle emergency steering collision avoidance and control method thereof

Abstract

The invention discloses an ESP and EPS combined system for vehicle emergency steering collision avoidance and a control method thereof. The system comprises a sensor unit, a controller unit and an actuator unit. The method comprises the steps that a sensor collects vehicle driving state information, and a longitudinal vehicle speed vx, a front wheel steering angle delta and a road adhesion coefficient mu are obtained; an ECU calculates an expected angular velocity through a two-degree-of-freedom vehicle dynamics model, calculates a maximum yaw velocity for ensuring the stability of the vehicle through a road adhesion limit, judges the misoperation degree of a driver, formulates a coordination control command and assists the driver in operation. A combined control structure strategy based on the ESP and the EPS is provided, coordinated control of the ESP and the EPS is achieved, the potential risk of instability of the vehicle can be reduced under the condition that an emergency steering driver operates mistakenly, the steering operation hand feeling of the driver is improved, and the psychological stress of the driver is reduced.

Description

technical field [0001] The invention belongs to the technical field of vehicle safety, and in particular relates to an ESP and EPS combined system and a control method thereof when the vehicle is in emergency steering and collision avoidance. Background technique [0002] With the increase of car ownership, there are more and more potential safety hazards on expressways, and a series of traffic accidents often occur due to car rear-end collision, instability, and turning. In order to improve the active safety performance of automobiles, the development of automobile Electronic Stability Program (ESP) is becoming more and more mature. When the driver encounters an obstacle in front of the car, the car often loses stability and turns after the driver turns. The function of ESP is to use the intervention of the power system and the braking system to help the vehicle overcome the tendency to deviate from the ideal track and provide the vehicle with better performance. Safety, e...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a combined system of ESP and EPS and its control method when the vehicle is turned in an emergency to avoid collisions, so as to solve the problem that ESP and EPS proposed in the above background technology are two independent systems, and their respective work does not interfere with each other. When a driver encounters an obstacle and turns suddenly, due to tension, fear and other reasons, he has lost accurate judgment on the steering wheel angle and the posture of the vehicle body, and is likely to turn the steering wheel indiscriminately. At this time, the steering system of the car and ESP's yaw moment controls the body to produce conflicts, making it impossible for the body to return to the ideal position. The EPS system is designed without considering the impact of the braking system. The power assist torque is only determined by the vehicle speed and the input torque of the steering wheel.

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