Direct tracking control using time-optimal trajectories

Abstract

Direct tracking control which is capable of high positioning speed and accuracy is developed using adaptive model-following control (AMFC). Direct tracking control relieves the difficulty and inconvenience of selecting the switching points in conventional hybrid control composed of bang-bang, velocity, and position control, AMFC can make the controlled plant follow, as closely as possible, a desired reference model where the time optimized positioning signal is generated. Direct tracking control using AMFC is applied to a tracking system of a magneto-optical disk drive to improve its slow tracking performance. Compared with the hybrid control system, the tracking time is much decreased in the direct tracking control system. According to the simulation and experimental results, an average access time as small as 19 ms is achieved.