Development of a Vehicle Stability Control System Using Brake-by-Wire Actuators

The wheel slip control systems are able to control the braking force more accurately and can be adapted to different vehicles more easily than conventional braking control systems. In order to achieve the superior braking performance through the wheel slip control, real-time information such as tire braking force at each wheel is required. In addition, the optimal target slip values need to be determined depending on the braking objectives such as minimum braking distance, stability enhancement, etc. In this paper, a vehicle stability control system is developed based on the braking monitor, wheel slip controller, and optimal target slip assignment algorithm. The braking monitor estimates the tire braking force, lateral tire force, and brake disk-pad friction coefficient utilizing the extended Kalman filter. The wheel slip controller is designed based on the sliding mode control method. The target slip assignment algorithm is proposed to maintain the vehicle stability based on the direct yaw-moment controller and fuzzy logic. A hardware-in-the-loop simulator (HILS) is built including electrohydraulic brake hardware and vehicle dynamics software. The effectiveness of the proposed stability control system is demonstrated through the HILS experiment.