Performance evaluation of dither distributions of piezo electric actuators for nano-positioning

Micro-nano positioning is a fast growing field in the context of its modern day implications in precision engineering industry. However, this apparently indispensable technique has its limitations imposed by the continuous manifestation of nonlinearities like hysteresis and creep. This work explores a relatively new control paradigm in the form of dither to successfully neutralize hysteresis, in particular for a Dahl Model based X-Y micro manipulator system working with feed-forward control mechanism. The efficiency of different dithers viz., Gaussian, Sinusoidal, Rician and Rayleigh have been put to rigorous tests and the best dither has been established in terms of relative reduction of tracking error. It is observed that a combined displacement and voltage dither significantly improves system performance as compared to an undithered system.