抄録
In order to reject the steady-state tracking error, it is common to introduce integral compensators in servosystems for constant reference signals. However, if we have an exact mathematical model of the plant and there is no disturbance to the plant, the integral compensation is not needed. From this point of view, a two-degrees-of-freedom (2 DOF) servosystem has been proposed in the recent literature. The present paper considers robust stability and a transient behavior of the 2 DOF servosystem. A class of uncertainties allowed in the plant model is obtained, to which the servosystem is robustly stable for any gain of the integral compensator. This result implies that if the plant uncertainty is in the class, a high-gain integral compensation can be carried out preserving stability to achieve a high-speed tracking response. The transient behavior attained by the limit of the high-gain compensation is calculated using the singular perturbation approach.
