Research On Torque Vectoring Differential Technology For Vehicle Stability Control

Vehicle stability control is the focus of automotive active safety technology nowadays. The most common used vehicle stability control system now is electronic stability program (ESP). Although it performs well on stability control, it has a problem that it will deteriorate the vehicle longitudinal driving performance when it is working becourse of braking. Aiming at this problem, a kind of torque vectoring differential (TVD) technology is advanced, and its application on vehicle stability control are studied. The basic working principle of TVD is as followed: desired yaw moment is calculated by the controller according to the driving condition, and the TVD can distribute the driving torque between the left and right driving wheels differentially to achive the desired yaw moment and correct the vehicle driving posture. In this way, vehicle active safety ability is enhanced while its longitudinal driving performance will not be affected.Firstly, the paper describes the superiority of TVD in the application of vehicle stability control, and introduces the related current research status and developing trend of TVD. Then, according to the torque transmission characteristic of clutch when coupling, a kind of TVD technology is advanced, and the basic structure and working principles of TVD are studied. The prototype modeling is built and kinematic analysis is performed in both SimDriveline and Solidworks/COSMOSMotion. According to the basic principles of vehicle system dynamics, mathematics modeling of vehicles equipped with TVD is done, a fuzzy logic control algorithm based on vehicle yaw rate is studied, and the hierarchical structure TVD controller is designed. In order to verify the control effect of TVD and its control algorithm, modeling of vehicles in different driving patterns and different TVD assembly modes are done with ve-DYNA. Software in loop simulations are performed in Simulink to test the TVD system and its control algorithm. Hardware in loop simulation sysem for TVD system is developed, which is based on ve-DYNA, NI LabVIEW, Compact DAQ and the integration among them. Experiments on the hardware in loop simulation sysem are carried out to validate the TVD control algorithm.Finally, the dissertation is summarized and some precious proposal is put forward to the next research.