Vibration reduction for positioning-system base subjected to moving stage using command shaping

Positioning stages are widely used for a variety of machinery. They are usually mounted on a heavy base, which is supported by soft springs for vibration isolation. Then motion of a positioning stage induces vibration into the whole system, including the positioning stage and the base structure, due to the inertial-reactive force effect, as well as the vertical moving-load effect. This paper investigates the vibration behavior and a vibration suppression method for a positioning-system base caused by the stage motion. A vibration suppression method is applied to reduce the residual vibrations in the base structure by modifying the velocity command for positioning stage using command shaping. Simulations are performed to find a command shaper appropriate for this problem. Experiments show that the proposed command shaping technique effectively removes the residual vibrations from the positioning-stage base and that command shaping can enhance the positioning accuracy of stage.