Ultrasonic linear motor for a high precision X-Y stage

Experiments on a mechanical configuration and control system for an ultrasonic linear motor for a high precision X-Y stage were conducted, and a velocity up to 100 mm/s and a positioning resolution of 0.016 mu m were obtained. The motor consists of a piezoelectric drive element using multilayer piezoelectric ceramic actuators. To realize both long-distance drive and very precise positioning, the ultrasonic linear motor has a coarse mode and a fine mode. The coarse mode is a friction drive mechanism and the fine mode is a direct-drive mechanism. The control system selects each mode according to the difference between a present position and an objective position.<
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