Latin American and Caribbean Consortium of Engineering Institutions

Conference Track:  Emerging Technologies

Selection1:       Paper

Language:         English

Keywords:         Ultrasonic motor, Piezoelectric actuators, Positioning control

Contact Title:    Prof.

Contact First Name: Antonio

Contact Last Name:  Moran

University:       Universidad Peruana de Ciencias Aplicadas UPC

Web:              http://www.upc.edu.pe

Position:         Director of Electrical Engineering Department

Country:          PERU

Email:            amoran@upc.edu.pe

Fax:              (51) 1 3133344

Paper Title:

Positioning Control System of a 3-Dimensional Ultrasonic Motor with Spherical Rotor

Abstract:

This project is concerned with the design of the control system for the accurate positioning of the spherical rotor of an ultrasonic motor equipped with piezoelectric actuators. The motor is intended to be used for trajectory following of flying objects as well as to support human articulations (shoulder, knee) of handicapped.

The ultrasonic motor has 3 disk-type piezoelectric actuators separated 120 degrees in a vertical arrangement to support and transmit motion to an spherical rotor. The rotor has a bar attached to it which moves in a spherical fashion.

The three stators are supplied with an electrical voltage of the same amplitude and frequency (about 50KHz) but with different phases. By varying the phases the rotor can rotate in any direction (except the z-axis) and the bar can be positioned to point any desired position.

To determine the position of the bar, two optical encoders are used and their signals are input to a computer which calculates the 3 phases to be applied to each stator. A control algorithm is proposed which integrates a complex structure of geometrical relations with a PI controller to compute the phases which should be limited to the range between -90deg to 90deg.

Experimental results show that the bar achieves the desired spatial positions and follows desired trajectories with fast response and good accuracy even in the presence of external disturbances.

These results demonstrate the feasibility of ultrasonic motors to perform positioning tasks with high degree of precision, robustness and autonomy.

Mailing Address:

Universidad Peruana de Cienias Aplicadas UPC

Av. Prolongacion Primavera 2390

Monterrico, Surco

Lima

PERU

Phone:

(51) 1 3133333

(51) 1 4483340

Authors:  

(1) Antonio Moran / amoran@upc.edu.pe / Universidad Peruana de Ciencias Aplicadas UPC / (P)

(2) Luis Leon / a810014@upc.edu.pe / Universidad Peruana de Ciencias Aplicadas UPC / (P)

(3) Miguel Rueda / a810052@upc.edu.pe / Universidad Peruana de Ciencias Aplicadas UPC / (P)

(4) Shigeki Toyama / Tokyo University of Agric. & Technology, Japan