抄録
This paper describes the positioning control of slide table comprising pneumatic cylinder and PCM control valves. A pneumatic servo system has advantages of the ease in constructing the control equipment, anti-explosibility and so on, however air compressibility makes it so sensitive to the friction and parameter variations that it is not easy to achieve high accurate control performances.
A Control system using a disturbance observer is constructed. It can estimate the friction force and parameter variation as a disturbance and compensate them, so the improvement of positioning accuracy and robustness for the parameter variations can be expected. Further, Smith's method is introduced to improve the lowering of stability margin caused by the dead time existing in almost pneumatic systems.
In this control system, the control performance depends on filter Q. One method to design Q using a inverse vector trajectory is proposed. By this method Q can be rationally designed considering both the stability margin and the gain of sensitiveness simultaneously. As a application of this method, control parameters which reconcile the improvement of sensitiveness and the positioning response without overrun are chosen.
Through some experiments, the validity of proposed control method is confirmed.
