In light of the former method's shortcoming

a new method was explored to improve clutch engagement quality.The clutch control requirements were determined based on the dynamics characteristic research of an unmanned helicopter clutch and the analysis of the effect of clutch engagement process on transmission impact and belt life.The rotating speed of clutch driving pulley and driven pulley were selected as basic input parameters.Ideal rotating speed curves were proposed.Three stages of engagement process adopted open-loop control

closed-loop control and open-loop control in turn.To realize the smooth and quick engagement

the closed-loop control adopted the combination of proportion integration differentiation(PID) control and fuzzy control.The experiments were conducted by using former control method and improved control method respectively.The results show that

as compared with former control method

the engagement time of improved control method shortens 1.5 times

the maximum jerk decreases 3 times

and the sliding friction work decreases twice. These prove that the improved control method can improve clutch engagement quality.