2006 Volume 72 Issue 722 Pages 3236-3241
Surface acoustic wave (SAW) linear motor is a kind of ultrasonic motors. The SAW linear motor has several advantages, such as thin structure, high thrust force, high velocity and precise positioning. Relationship between applied voltage and output velocity, however, had non-linearity in low velocity range due to friction drive principle. Therefore the SAW linear motor cannot obtain stable driving without feedback control at low velocity. To realize low velocity, PWM (pulse width modulation) control and flexible slider structure are employed. The flexible structure is installed to cancel vibration due to PWM carrier frequency. In this research, PWM is applied for controlling the slider velocity. Lower velocity in non-linear range is realized. Influence of the flexible structure upon precise positioning is investigated.