Coaxial-coupling traction control for a four-wheel-independent-drive electric vehicle on a complex road

Abstract

An independent-wheel-drive electric vehicle has the advantage of better implementation of precise motion and stability control. However, when the vehicle is moving on a road that has complex slopes and various adhesion coefficients and is subjected to the structural limitations of the independent-wheel-drive systems, the driving performance will deteriorate. In order to make full use of the drive torque of every motor to improve the vehicle’s climbing and accelerating abilities, on the basis of the designs of a dual-motor coaxial-coupling independent-wheel-drive system and a sliding-mode controller, a coaxial-coupling traction control system was developed. Simulations on coaxial-coupling traction control for a four-wheel-independent-drive electric vehicle were completed. With the innovative coaxial-coupling equipment, the drive torque can be satisfactorily transferred between the wheels at the two sides of one drive shaft. When one of the driving wheels begins to slip, the torque transmission will increase rapidly, the probability that wheel slipping occurs will be reduced and the vehicle’s driving force can be enhanced. Also, the chatter of the traction control system can be quietened effectively, and the dynamicity and trafficability can be improved. In addition, with the additional yaw moment generated by the torque coupling, the system also has the auxiliary effect of improving the high-velocity lateral stability of the vehicle on a road which has a low adhesion coefficient.