A State Variable Fully Constrained Direct Yaw Moment Control Algorithm Based on Road Adhesion Coefficient

Abstract

The invention discloses a state variable full-constraint direct yaw moment control algorithm based on road surface adhesion coefficient. The invention introduces the concept of obstacle Lyapunov function (BLF) into the design of direct yaw moment controller. During the design process of the road surface adhesion coefficient, the safety constraint boundaries of the two state quantities of the side slip angle and the yaw rate brought about by the road surface adhesion coefficient are taken into consideration. It ensures that the sideslip angle and yaw rate of the center of mass do not violate the constraint conditions in the tracking control, and fundamentally avoids the failure of the vehicle such as tail flicking and lateral drift caused by excessive sideslip angle and yaw rate under extreme conditions. The stable working condition improves the lateral stability of the vehicle during driving. At the same time, the direct yaw moment full-state constraint controller of the present invention has faster tracking convergence time without violating constraint conditions, and reduces the possibility of occurrence of dangerous working conditions.

Description

technical field [0001] The invention relates to the field of automobile steering control, in particular to a direct yaw moment control algorithm based on the full constraints of the road surface adhesion coefficient on the side slip angle of the center of mass and the yaw angular velocity. Background technique [0002] During the sharp turn of the vehicle, the vehicle will produce changes in the center of mass side slip angle and yaw rate. When the vehicle speed is too fast, the center of mass side slip angle and yaw rate of the vehicle will increase sharply, which may exceed the safety range of the center of mass side slip angle based on the road surface adhesion coefficient [-tan -1 (0.02μg),tan -1 (0.02μg)] and yaw rate safety constraint range [-μg / u x ,μg / u x ](μ is road adhesion coefficient, g is gravitational acceleration, u x is the longitudinal speed of the vehicle). If the side slip angle of the center of mass is too large, the wheels will slip, the vehicle wil...

AI Technical Summary

Problems solved by technology

Although these stability control methods focus on improving the response characteristics and robustness of the optimal value tracking, they ignore the fact that there is a certain range of safety constraints on the side slip angle and yaw rate, or they only regard the stability boundary as a threshold warning , reach or exceed the upper and lower bounds to call back, it cannot ensure that the state quantity is always within the safe range

This situation will lead to a decrease in the lateral stability of the vehicle, and in severe cases, it will lead to dangerous situations such as vehicle body instability.

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