| A servomechanism is a system that controls the position or velocity of a mechanical devise. In many applications, such as disk-drive head positioning and pick-and-place robots, it is desirable to have servomechanisms effect a minimum time response. Since there is a limit on the magnitude of the control signal in every control system, this leads to time-optimal controllers that are bang-bang. Truly bang-bang time-optimal control systems are not practical, due to the poor overall behavior such as the instantaneous switching and the limit cycles about the target state. In order to eliminate such undesirable behavior, we apply Continuous Proximate Time-Optimal (CPTO) controller to a third order servomechanism having three real roots, which represents our modeling of the hard disk drive servomechanism. We have shown that the CPTO controller gives near time-optimal response for large states, and provides smooth and stable response with near linear control for small states. (Abstract shortened by UMI.)... |
