Abstract:To improve the lateral stability of electric vehicles driven by rear wheel hub motor, a hierarchically coordinated vehicle dynamics control approach is presented. The high-level controller is based on the theory of model predictive control using Laguerre functions and it is designed to determine generalized moment by tracking the desired yaw angular velocity which is limited by the constraint of additional yaw moment. The low-level controller takes the rear wheels' work-load rate as the objective function and distributes the additioral yaw moment to the two rear wheels by solving quadratic programming. And the constraint problems caused by the road adhesion and actuators are considered in the quadratic optimization. The control method is verified by Carsim and Matlab/Simulink under the conditions of a single step steering input and double-lane change, respectively. Simulation results show that under the condition of high adhesion road, the control method can reduce the reaction time and overshoot, and improve the quality of the transient response of vehicles; under the condition of low adhesion road, it makes cars track the desired yaw angular velocity and avoid cornering instability.