Analysis of Dynamic Behaviour for a Lead Screw-Type Positioning System Using Linear Graph Theory. Transient Response Analysis of Feedback Control System and Reduction of Positioning Time.

Recently, the fine positioning system has been used in the mechanical industry, and has required the improvement of positioning accuracy, reduction of positioning time, increase of carrying capacity and so on. However, the existing control method for the positioning stage may cause delay of phase response or residual vibration when disturbance or overweight acts on the system or stage drives at high speed. In order to obtain the optimum control inputs, it is necessary to grasp the dynamic behaviour of the system precisely. First, this paper deals with the transient response of the positioning stage using the linear graph theory reported in the previous papers. The simulated results of transient response of the positioning stage are compared with the experimental ones, and they are found to be in good agreement. Next, a procedure which can reduce the settling time of positioning is proposed by utilizing this method. As a result, this procedure was able to reduce the settling time by 55%, as compared with only proportional control.