THE WORKING PRINCIPLE AND EXCITATION METHOD OF A STEP PERISTALSIS PIEZOELECTRIC ACTUATOR

A step peristalsis actuator using piezoelectric stacks is proposed, designed and analyzed. The proposed actuator contains four piezoelectric stacks located in U-shaped: the two horizontal piezoelectric stacks are used to push the runner, while the two vertical piezoelectric stacks are used to change the contact states between the two feet and the runner. And the working principle for bidirectional-linear-driving is discussed. According to the working principle, the exciting method is developed to obtain the sequence control signals of the piezoelectric stacks. It is found that the step peristalsis piezoelectric actuator can achieve the accuracy of nanometer and be used as a bidirectional actuator. At last, the driving power of the step peristalsis piezoelectric actuator is investigated by theoretical analysis and designed. At present, the proposed design can be used as a long-stroke, ultra-precision and bidirectional piezoelectric actuator.