Abstract: Precise ETC(Electronic Throttle Control) is critical to powerful torque-based engine management system. Aiming at the problems brought by the non-linearity of the restoration spring of the electrical throttle, combing the the electric throttle structure, its non-linearity is analyzed.The sliding mode control algorithm is adopted and its stability certification is given. Experiment with conventional PID(Proportional Integral Derivative) and sliding mode control is carried out on the electrical throttle using the control board based on 16 bit 80C196KC singlechip. The experiment shows that when variable PID is used, no overshoot exists when the open degree of ECT changing from small degree to large degree, and when its changing from large degree to small degree, the overshot is 48％.Whiling the sliding mode is used no overshoot exists when the open degree of ECT changing from small degree to large degree, when its changing from large degree to small degree, the overshot is 1％,is reduced greatly. The sliding mode control system has a good control result to the non-linearity of ETC.

Key words: non-linearity sliding mode control, electronic throttle control（ETC）, engine manage system