Self-moving cell linear motor using piezoelectric stack actuators

Abstract

In this paper, a self-moving cell linear motor (SCLM) using a piezoelectric stackactuator is designed, manufactured, and evaluated. The self-moving cell consists ofan oval-shaped shell structure and piezoelectric stack actuator. The self-movingcell concept is different from a conventional inchworm linear motor because theSCLM has unified clamping and push devices. The clamping force of the SCLMis determined by the interference dimension and the friction between the shellstructure and guideway. Thus, this motor can generate a large clamping force andmaintain a fail-safe lock. The most important part in designing the SCLM isthe shell structure. Finite element analysis and the Taguchi method are used tooptimally design the shell structure. The performance of the SCLM is tested inmacro- and micro-motions. In macro-motion, the SCLM exhibits the maximum speed of100 µm s−1 and the blocking force of 3.7 N. Since the load capacity of the motor is determined mainlyby the friction force between the shell structure and guideway, a large load can bemaintained at low speed. In micro-motion, PID control is used to overcome the hysteresisof piezoelectric stack actuators and the possibility of precise tracking control of the desiredtrajectory is demonstrated.