Abstract
PID control is widely used to control mechanical systems. But, PID control has a limit of accuracy due to the influence of nonlinear force: gravity, friction and so on. In contrast, digital acceleration control (DAC) has robustness for the nonlinear effects. Therefore, a combined control system of PID and DAC (PID-DAC) has been proposed in previous studies. However, control performance of this system deteriorates when PID-DAC is applied to control an object with high acceleration. In this paper, we propose two novel nonlinear compensators which are based on digital acceleration control technique. The validity of the proposed methods is confirmed by simulations and experiments.
