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2. Actuator with Friction Drive : Ultrasonic Motor
3. (4) Nogarede, B. and Piecourt, E., Modelisation of a Travelling Wave Piezoelectric Motor by Equivalent Electrical Circuit Proceedings of the International Conference on Electrical Machines, (1994), pp.128-133.
4. Travelling wave ultrasonic motors, Part I: Working principle and mathematical modelling of the stator