Design and experimental investigation of rotational angle based tracking control

Abstract

This work investigates the tracking control in the rotational angle domain based on the time-varying internal model principle. The focus is to enable precise, reliable and computational efficient output tracking/disturbance rejection in the angle domain. To achieve better performance, existing approaches typically require more discrete samplings per revolution, which can drastically increase the controller order and also poses challenge for the stabilizer convergence. To address those issues, a varying sampling interval approach is proposed, where the control sampling rate is not fixed but optimized based on errors between sampling points, so that proper regulation performance can be achieved without significantly increasing the number of sampling points. Meanwhile, to improve the convergence rate of the tracking error, additional LMI constraints are added to the existing stabilizer synthesis. Through experimental study on a camless engine valve actuation system, the effectiveness of the proposed approaches is well demonstrated.