With the development of nano-measurement technology, studies on enable multiple degrees of freedom nanometer positioning fretting table have caught more and more attention. Micro-table driving elements selection and use have a direct impact on the ultimate performance. Currently, there are many kinds of small displacement driving elements used in practice. And piezoelectric actuators has become one of the most widely used driving element in micro-positioning control areas for its small size, light weight, low the driving voltage, high precision and displacement resolution, fast frequency response, no heat, no noise, large capacity and other characteristics.

 

However, the inherent nonlinear characteristics, hysteresis characteristics and creep properties of piezoelectric ceramic material, have greatly limited the further improvement of piezoelectric actuator positioning accuracy, wherein the hysteresis error has the maximum impact on the accuracy. Therefore, how to improve the piezoelectric actuator hysteresis characteristics has become the most important issue need to be resolved of our ultra-precise positioning. In this regard, experts and scholars at home and abroad have done a lot of research and put forward a series of theories and methods to improve its characteristics. The methods to reduced latency in the drive open loop or semi-closed loop control currently proposed are: (1) The charge control method; (2) Connecting in series of small capacitance at both ends of the piezoelectric ceramic ; (3) Preisach model; (4) Generalized Maxwell model; (5) Polynomial approximation model; (6) Making capacitors and resistors as bridge. These methods control mostly through the establishment of complex mathematical models.

 

In this study, a new kind of hard piezoelectric actuator with tungsten bronze structure was used. Compared to soft perovskite piezoelectric actuators, hysteresis characteristics and creep error of this driver are greatly improved, especially the performance is relatively stable on the aspect. According to the main reason of generating hysteresis in the deformation process in their domain structure and crystal structure, some scholars have proposed a new "anti-hysteresis" driving method. "Anti-hysteresis" driving method can greatly reduce the impact of driving piezoelectric ceramic actuator hysteresis error, which can be used in high precision open-loop control of the micro device of which the process does not require continuous positioning, which greatly improves the hysteresis characteristics of the piezoelectric ceramic drive.