Automotive engine speed control: A robust nonlinear control framework

A controller design procedure based on sliding-mode techniques is presented for speed control in an automotive engine. Only the engine speed and manifold pressure measurements are available to the control law. It is assumed that the load-torque disturbance on the engine is not known, while uncertainties in the system parameters are also taken into consideration. The engine acceleration is estimated through a high-gain observer. A comprehensive nonlinear simulation model is used to assess the performance of the closed-loop system. It is shown that the sliding-mode controller can achieve the full range of setpoint speeds. In addition, the closed-loop system is robust with respect to both initial speed and changes in the load torque