Abstract: Clutch control for a vehicle equipped with an automated manual transmission (AMT) during starting process is a multi-objective optimization problem. So the optimal control strategy, based on the minimum cost function of multi-objective constraints, is more suitable for the starting control of AMT vehicles theoretically. However, the weight coefficients in the optimal control strategy are chosen by the designers' subjectivity without definite theories in previous researches. Therefore, the influence of the weight coefficient variation on the starting performance of vehicle is studied in this paper. Firstly, the clutch model is established and the optimal control algorithm is used to design the linear quadratic regulator (LQR), in which the friction time, impact and friction work are selected as vehicle starting optimization indexes. Secondly, according to extreme driving styles, the variation ranges of weight coefficients are determined by analytic hierarchy process (AHP). Finally, the variations of vehicle starting performance indexes when weight coefficients change are investigated and analyzed by a large number of simulation experiments.

Key words: clutch optimal control, weight coefficient, analytic hierarchy process, driving style