Piezo-actuated stages have become more and more promising in nanopositioning applications due to the excellent advantages of the fast response time, large mechanical force, and extremely fine resolution. Modeling and control are critical to achieve objectives for high-precision motion. However, piezo-actuated stages themselves suffer from the inherent drawbacks produced by the inherent creep and hysteresis nonlinearities and vibration caused by the lightly damped resonant dynamics, which make modeling and control of such systems challenging. To address these challenges, various techniques have been reported in the literature. This paper surveys and discusses the progresses of different modeling and control approaches for piezo-actuated nanopositioning stages and highlights new opportunities for the extended studies.

Modeling and Control of Piezo-Actuated Nanopositioning Stages: A Survey

A review of recent studies on non-resonant piezoelectric actuators

Piezoelectric actuators (PEAs) are widely used in the nanopositioning applications due to their high stiffness, fast response, and ultrahigh precision. However, PEAs inherently have the hysteresis nonlinearity which can dramatically degrade the tracking performance. This paper proposes an adaptive Takagi–Sugeno (T–S) fuzzy model-based predictive controller with a parallel distributed control structure. Compared to the previous results, the proposed controller does not require the inverse hysteresis model of PEAs, and is easy to be calculated because the predictive subcontroller for each T–S fuzzy rule has an explicit form. Meanwhile, the parameters in the T–S fuzzy model can be online adjusted according to the real-time tracking error feedback, and the offline training accuracy of the T–S fuzzy model is no longer a serious concern. In addition, some physical constraints of the proposed controller can be well handled. To verify the proposed method, experiments are conducted on a commercial PEA product, and experiment results show that the proposed method has a satisfactory tracking performance. Furthermore, comparisons with some existing controllers are made and the proposed adaptive fuzzy model-based predictive controller outperforms these controllers.

Xueliang Wang

Papers

A simple fuzzy system for modelling of both rate-independent and rate-dependent hysteresis in piezoelectric actuators