Research on transfer case clutch accurate position control of on-demand four-wheel drive systems

Abstract

<p indent="0mm">The on-demand four-wheel-drive system has been widely used because of its simple structure and low cost. The core component of the on-demand four-wheel-drive system in this study is a transfer case based on an electronically controlled multi-plate wet clutch. Its actuator consists of a worm gear driven by a permanent magnet synchronous motor and a helical booster mechanism. The actuator can control the position of the clutch pressure plate to change the drive torque transmitted to the front axle, and adjusting the front axle torque significantly affects the handling stability and dynamics. Therefore, the precise position control of the transfer clutch is of great significance. In this paper, a model of the PMSM actuator system and load is first established, which provides the basis for the design of the controller. Then, explicit model predictive controllers for current tracking control and position tracking control are designed based on the model. Finally, typical working condition position tracking simulations and experiments are carried out. The results show that the proposed position control algorithm can achieve relative accuracy of 1%, which can meet the requirements of the real-time online high-precision position control of an on-demand four-wheel-drive system.