Double closed‐loop control with adaptive strategy for automotive engine speed tracking system

In order to improve the transient and static performances of an engine speed control system in a wide speed range, this paper presents an adaptive double closed‐loop control strategy. The control scheme possesses intake manifold pressure inner closed‐loop adaptive proportional‐integral control and engine speed outer closed‐loop adaptive proportional‐integral control for achieving the tracking precision in a wide range of speed, as well as adaptive nonlinearity and feedforward compensators for overcoming parameter uncertainty and nonlinearity. The whole closed‐loop system's stability and the speed tracking convergence are ensured theoretically by the Lyapunov stability theory and the LaSalle invariant principle. The effectiveness of the proposed control strategy is validated through the operation results on the simulator of a V6 engine exploited by the Research Committee of the Society of Instrument and Control Engineers of Japan.