A Dry Clutch Engagement Controller with Thermal Effects Compensation

Single and dual dry clutches are widely used in automated manual transmissions because of their reliability and efficiency, low fuel consumption, reduction of pollutant emissions. These goals are achieved by adopting a “good” clutch model and by designing a robust control strategy. For this purpose, the clutch torque estimation is a key issue as it can be used to implement a feedback action in order to compensate for the temperature effects and model uncertainties. In this paper a transmissibility model of a dry clutch which includes the thermal effects is proposed and used for the design of a corresponding closed-loop control strategy. The control action consists of two contributions, one based on the inversion of the torque characteristic and another derived from an estimate of the clutch torque through an observer. A start-up engagement maneuver in a medium size passenger car is considered to validate the controller and its effectiveness is confirmed by numerical results.