An active front wheel steering control method for electric vehicles with automatically adjustable control parameters

Abstract

The invention discloses an active front wheel steering control method of an electric vehicle whose control parameters can be automatically adjusted, and belongs to the field of new energy electric vehicle control. The control method can improve the stability of the vehicle under extreme working conditions. The main steps are: 1. Establish a linear two-degree-of-freedom vehicle dynamics model, calculate the ideal yaw rate of the vehicle through the model, and design an active front wheel steering control module for electric vehicles based on discontinuous control technology; 2. Establish an observer module to estimate Control the average value of the input medium and high frequency signals; 3. Establish an adaptive module to construct a time-varying control gain according to the average value. The advantages of the present invention are as follows: firstly, the vehicle can respond quickly and automatically in extreme environments, improve the accuracy of the active front wheel steering system, and reduce the occurrence of traffic accidents; secondly, the control in the traditional terminal sliding mode method is significantly reduced The gain reduces potential chattering problems; thirdly, the control method has a simple structure, a small amount of computation, and is easy to implement.

Description

technical field [0001] The invention relates to a control strategy for active front wheel steering of an electric vehicle, and belongs to the field of new energy electric vehicle control. Background technique [0002] Compared with traditional cars, hub-type electric vehicles simplify the chassis structure, omit most of the traditional components, improve the transmission efficiency, and the driving or braking force of the four wheels is independently controllable. [0003] Active front wheel steering means that within the linear range of the lateral force of the vehicle tires, an additional angle of rotation is applied to the front wheels through the actuator, which does not depend on the input of the steering wheel, corrects the steering angle of the car, improves the steering accuracy, and realizes active steering. . Active front wheel steering is a steering system between traditional power steering and steer-by-wire. It not only has the structural foundation of mechanic...

AI Technical Summary

Problems solved by technology

However, compared with the discontinuous control method, the controller based on the continuous control method is relatively less robust to external disturbances and system uncertainties

Therefore, under complex working conditions, the direct yaw moment control based on the continuous control method is sometimes difficult to achieve a satisfactory control effect

On the other hand, although discontinuous control has strong robustness, it can well overcome various uncertainties and disturbances in the dynamics of electric vehicles, but because its controller is discontinuous, it will generate a large number of Chattering, even causing system crashes

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