Steering stability control method for four-wheel drive electric vehicle

Abstract

The invention discloses a four-wheel drive electric automobile steering stability control method. When a vehicle is judged to be turned, the yaw moment offset is calculated; and when it is judged that the steering is insufficient, inner-side front wheels and rear wheels inside are controlled to perform braking energy recovery to generate a yaw moment; if the braking yaw moment is larger than or equal to the yaw moment offset, the inner-side front wheels are controlled to perform braking energy recovery, and when the maximum charging condition of the inner-side front wheel energy is reached, the inner-side rear wheels are controlled to perform braking energy recovery until the yaw moment offset is eliminated; and if the braking yaw moment is smaller than the yaw moment offset, the inner-side front and rear wheel brake energy is controlled to recover and increase the outer side front, the rear wheels drive the torque, and the target slip rate is used as a control object to coordinate the output of the torque, and the deflection amount of the yaw moment is eliminated; and when it is judged that the steering is over, the front wheels and the rear wheels outside are controlled to perform braking energy recovery, and the control strategy and the steering insufficiency are the same. Torque control can be performed on each wheel, and stability and robustness of control are improved.

Description

technical field [0001] The invention relates to a vehicle body dynamic control method of an electric vehicle, in particular to a steering stability control method of a four-wheel drive electric vehicle. Background technique [0002] As the technology of new energy electric vehicle components continues to mature, more and more models are launching pure electric versions. When electric vehicles are turning, it is easy to oversteer, sometimes accompanied by understeer. [0003] Existing body dynamic control methods mainly rely on the hydraulic brake system as the actuator, for example, the antilock brake system (antilock brake system, ABS) and the electronic stability program (ESP) are based on Hydraulic braking of single or multiple wheels for yaw moment control. However, there are many problems in generating yaw moment through hydraulic braking. For example, the overheating of the brake disc will cause thermal decay, which will affect the braking performance; there may be a ...

AI Technical Summary

Problems solved by technology

This method controls rear-wheel drive vehicles with centralized motors. All control strategies are only applicable to rear-wheel drive vehicles, and cannot be used on front-wheel drive and four-wheel drive vehicles. Vehicle tracking deviation, this control method is not suitable for body attitude control with large dynamic changes, such as elk test

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