Nonlinear Backstepping Tracking Control for a Vehicular Electronic Throttle With Input Saturation and External Disturbance

To achieve more precise positioning of the electronic throttle plate, a nonlinear backstepping tracking control strategy is presented in this paper. In contrast to the existing control schemes for electronic throttles, the input saturation and unknown external disturbances are explicitly considered in the tracking control design. The difficulties in controlling an electronic throttle include the strong nonlinearity of the spring and friction as well as the unknown external disturbance. In particular, the valve plate angle is adjusted by the control input voltage of the driving motor, and the input voltage is limited to a certain range. Therefore, input saturation problems exist in the control system for an electronic throttle. To overcome the abovementioned difficulties, an auxiliary design system is presented to handle the input saturation, and its state is applied in the proposed control design. A sliding-mode control term is also utilized in the tracking controller to counteract the unknown external disturbance. The proof and analysis show that the satisfactory tracking performance of the valve plate angle can be achieved by using the designed control scheme for the electronic throttle system in the presence of input saturation and unknown external disturbances. Simulation studies and results are provided to illustrate the desired performance of the proposed nonlinear tracking controller.