Sun Chengshun

Zhang Jianwu

School of Mechanical and

Power Engineering,

Shanghai Jiaotong University,

Shanghai 200030, China

AUTOMATIC CLUTCH ENGAGEMENTS OF VEHICLES

Abstract: Start-up working condition is the key to the research of optimal engagement of automatic clutch for AMT. In order to guarantee an ideal dynamic performance of the clutch engagement, an optimal controller is designed by considering throttle angle, engine speed, gear ratio, vehicle acceleration and road condition. The minimum value principle is also introduced to achieve an optimal dynamic performance of the nonlinear system compromised in friction plate wear and vehicle drive quality. The optimal trajectory of the clutch engagement can be described in the form of explicit and analytical expressions and characterized by the deterministic and accurate control strategy in stead of indeterministic and soft control techniques which need thousands of experiments. For validation of the controller, test work is carried out for the automated clutch engagements in a commercial car with an traditional mechanical transmission, a hydraulic actuator, a group of sensors and a portable computer system. It is shown through experiments that dynamic behaviors of the clutch engagement operated by the optimal control are more effective and efficient than those by fuzzy control.

Key words: Automatic clutch  Optimal control  Nonlinear system dynamics