Position-based impedance torque control for automatic clutch with robust predefined-time stability guarantee

Abstract

Accurate clutch torque control is essential in improving vehicle comfort, drivability, and fuel economy. In this article, for automatic clutch system with electro-hydraulic clutch actuator, a clutch torque control strategy with a robust predefined-time stability guarantee based on position closed-loop impedance control is proposed and evaluated. For this purpose, a general second order model of electro-hydraulic clutch actuator with a disturbance term is established. Based on this model, a reference position compensator based on force control in the outer loop and a predefined-time backstepping position controller in the inner loop are developed. In addition, to obtain the release load of the release bearing, a virtual sensor is designed, composed of an online adaptive sliding mode disturbance observer with predefined-time stability and an offline Gaussian process model of uncertain disturbance based on the Gaussian process machine learning method. Finally, simulations and experiments are completed to verify the proposed control strategy. The results show that the control strategy can realize the precise clutch torque tracking control and achieve satisfactory performance.