Toward the implementation of an ultrasonic motor servo drive using CPLD/FPGA

Most electric motors, in which electromagnetic torque is utilized, are based on the energy conversion from electrical to magnetic then to mechanical energy. An ultrasonic motor, however, is driven by an ultrasonic vibration with direct contact between the stator and rotor; thus the size can be made compact and can provide inherent braking while stopping. The driven frequency is higher than the audible frequency of human ears; thus while operating it is relatively quiet. In this paper, the authors design and implement an ultrasonic servomotor drive using a complex programmable logic device (CPLD). Experimental results show the feasibility of this implementation