1. Improvements in Controllability of Ultrasonic Linear Motors by Longitudinal-Bending Multilayered Transducers with Independent Electrodes
- Author
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Kentaro Nakamura, Mikio Takimoto, Masahiro Takano, Satoru Ichimura, and Kenichi Hirosaki
- Subjects
Controllability ,Vibration ,Longitudinal mode ,Nonlinear system ,Materials science ,Transducer ,Physics and Astronomy (miscellaneous) ,Acoustics ,Ultrasonic motor ,General Engineering ,General Physics and Astronomy ,Ultrasonic sensor ,Linear motor - Abstract
Ultrasonic motors are nonlinear in input–output characteristics, which causes problems for precise control. To obtain good controllability and realize low-cost fabrication, we proposed an ultrasonic linear motor using a multilayered transducer with independent electrode sets for the first longitudinal mode and the second bending mode. We can change the shape of the vibration locus at the friction head arbitrarily by independently controlling the amplitude and phase of each vibration component. Controllability in the proposed motor was investigated by changing the shape of the vibration locus. In the proposed motor, the nonlinear part of the input–output characteristics is suppressed to 1/20 of that in conventional ultrasonic motors. As a result, a good positioning resolution of 20 nm and a low-speed drive of 0.1 mm/s were obtained with a simple closed-loop control system.
- Published
- 2011