New compact travelling-wave type power ultrasonic motor actuated speed tracking servo system and feasible evaluations

This paper describes the schematic review of traveling-wave type ultrasonic motor (T-USM) and a newly-proposed weight-quality speed tracking controller of T-USM based on computer software-based variable-gain adjustment strategy. Its speed tracking characteristics capable of improving speed ripple, speed regulation and speed tracking characteristics are feasibly demonstrated in experiment as compared with a previously-developed fuzzy-logic speed controller of T-USM actuated servo drive system. It is proved that T-USM speed control scheme developed herein is practically acceptable for direct-drive speed servo system.