20150270790 | ULTRASONIC MOTOR CONTROL SYSTEM AND METHOD - A method of controlling an ultrasonic motor coupled to a motor driver circuit, comprises receiving a temperature signal representing the temperature of the ultrasonic motor, receiving a position signal output by a first encoder representing the position of the ultrasonic motor, calculating an error between the position of the ultrasonic motor represented by the position signal and a target position, calculating a control signal based on the temperature of the ultrasonic motor represented by the temperature signal and the calculated error, and sending the control signal to the motor driver circuit to control the ultrasonic motor. | 09-24-2015 |