Dry Clutch Control Based on Electromechanical Actuator Position Feedback

The paper presents identification and control of an experimental dry clutch actuated by a geared dc motor and ball-ramp mechanism. The identification results are used to describe the multi-dimensional clutch friction coefficient characteristic. The proposed clutch torque control system is based on closed-loop actuator position control and the identified friction coefficient curves. In order to compensate for a clutch pack thermal expansion effect, which affects the torque control accuracy, the control strategy is extended with feedforward or feedback path that outputs a position reference additive signal. The torque control strategy is verified experimentally within a clutch slip speed control system.