Nonlinear PID control of electronic throttle valve

An electronic throttle can regulate air inflow into the combustion system of the engine. However, because of the exist nonlinearities including friction, nonlinear spring in the system, it is difficult in controlling the throttle valve. A nonlinear PID controller is proposed in this paper, it constantly adjusts the controller parameters proportional gain P, integral gain I and differential gain D with the system error changing. A simulation is provide to verify the effectiveness of the nonlinear PID strategy.