A robust invariant set control method for preventing oversteering of four-wheel independent drive electric vehicles

Abstract

The invention discloses a robust invariant set control method for preventing oversteering of a 4-independently-driving-wheel electric vehicle. The method comprises the following steps: determining a rear axle wheel side slip angle constraint value alpha(m) for preventing saturation of lateral force of a vehicle rear axle; converting a rear axle wheel side slip angle constraining problem into a problem on constraining control over expression of a vehicle centroid side slip angle beta and a yaw rate gamma: as shown in the specification; by taking the formula as shown in the specification, dividing a space with the vehicle centroid side slip angle serving as a transverse coordinate and the yaw rate serving as a longitudinal coordinate into two spaces; when the vehicle centroid side slip angle and the yaw rate fall within the space where a rear axle wheel side slip angle does not exceed the constraint value, applying a yaw rate tracking control method capable of guaranteeing a stable closed loop; when moving tracks of the vehicle centroid side slip angle and the yaw rate are intersected with a constraint equation, which is as shown in the specification, designing a robust invariant set controller to control the vehicle centroid side slip angle and the yaw rate to fall within one invariant set of an intersection. According to the robust invariant set control method, constraining of the vehicle centroid yaw rate and the vehicle centroid side slip angle is realized, so that the control aim of preventing the oversteering is fulfilled.

Description

technical field [0001] The invention belongs to the technical field of yaw stability control for electric vehicles, and relates to a control method for preventing over-steering of four-wheel independently driven electric vehicles. Background technique [0002] Yaw stabilization control is used to improve the steering stability of the vehicle. Traditional vehicle yaw stability control enables the vehicle to generate yaw moment through additional braking torque to prevent understeer or oversteer of the vehicle and improve steering safety. Since the braking torque should not be applied for a long time, conventional vehicle yaw stability control only intervenes when understeer or oversteer is recognized. The four-wheel independent drive electric vehicle has the characteristics of continuously adjustable driving torque of the four wheels and fast response speed. By adjusting the driving torque of the four wheels, the vehicle can generate yaw moment and realize the yaw stability ...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problem that there is no effective method for preventing oversteering in the yaw stability control process of four-wheel independent drive electric vehicles, the present invention provides a robust invariant set control method for preventing oversteering of four-wheel independent drive electric vehicles. Through the robust invariant set control method, the constraints on the yaw rate of the center of mass and the side slip angle of the center of mass are realized, so as to achieve the control goal of preventing oversteer

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