A method for auto-adjustment of a new Piezoelectric drive

Piezoelectric Actuator Drives (PADs) introduce a new kind of rotary motors, combining high dynamics, torque, and positioning accuracy. The working principle is based on a micro-toothed pair of ring and shaft, which guarantee form-fit and continuous force transmission. Due to miniaturization constant speed and absolute positioning accuracy depend on precise adjustment and therefore demand control to overcome mounting tolerances and thermal influence. In this paper a method for adjusting the PAD is presented, which makes use of the smart sensing function of the piezoelectric elements. In a simplified model the expected feedback will be calculated and an appropriate closed-loop controller will be proposed.