Adaptive control strategy for micro/nano manipulation systems
Micro/nano manipulation has been identified as one of the key enabling technologies for many emerging areas of application. Within this scope, piezoelectric actuators have played a major role in achieving the required nano-resolution motion. This paper proposes an adaptive control strategy for the manipulation systems driven by piezoelectric actuators to follow specified motion trajectories. This is motivated by a search for an effective control methodology to deal with the problem of parametric uncertainties such as disturbance and hysteresis effects. The proposed adaptive strategy is formulated by introducing a parameter compensator for a system to drive its position tracking error to converge to zero. The fundamental concept lies in the properties of a quasi-natural potential function, which allows a saturated position error function in the control formulation. Implementation of the control law requires only a knowledge of the initial estimate of the system parameters. Feasibility study of the control strategy for a micro/nano manipulation system is presented. Simulations are performed to validate the suitability of the proposed control methodology.