Due to the individual controllability of each motor, the distributed driven
electric vehicle has provided a broad research domain for vehicle integrated
control. This paper focuses on vehicle stability control by the integration of
three systems, the hydraulic brake unit, active steering unit, and motor torque
control unit. Firstly, the hierarchical control strategy has been designed
generally, which is divided into three levels, the upper controller, medium
controller, and lower controller. Secondly, based on the hierarchical structure,
each controller has been introduced in detail. The upper controller is the
application layer, which has implemented the functions such as the estimations
of vehicle states and road conditions, calculation of nominal control variables,
identification of vehicle stability and steering characteristics, and the
coordinated algorithm of additional yaw moment and active front angle, etc. The
medium controller is the decision and allocation layer, which primarily finishes
the coordination of brake and motor control. The lower controller is the
execution layer, which is mainly to control three actual variables (the pressure
of brake wheel, the torque of each motor, the angle of front-wheel) to follow
the expectations. Finally, to validate the effectiveness of strategy proposed,
the Hardware In-the-Loop (HIL) tests are conducted on two typical conditions,
compared with the strategy without active front angle control and only hydraulic
brake control, the results have shown that the strategy proposed has a better
property on vehicle stability.