ABSTRACT
The history of piezoelectric materials dates back to 1880, when Pierre and Jacques Curie published the first experimental demonstration of piezoelectricity in various materials such as rochelle salt, quartz, and tourmaline. When these crystalline materials are subjected to tensile or compressive forces, they become electrically polarized. This chapter discusses a linear ultrasonic piezo motor is used as an illustrative example, and its structure, working principle, and speed characteristics. The amplitude of the displacement is maximum when the frequency of the exciting voltage is equal to the natural resonant frequency of the ceramic plate. The inductor between the common plate C and the ground tunes the electrical resonance frequency to its mechanical resonance frequency. Various deadzone compensation schemes have been proposed. Since the magnitude of the static friction is almost invariant, a feedforward compensation scheme can be implemented using the velocity reference and position error signals.
