Optimal control based active force sensing system for micromanipulation

Abstract

This paper presents the development of an active force sensing technology for micromanipulation using in-situ polyvinylidene fluoride (PVDF) layers symmetrically bonded to the surface of a flexible cantilever beam structure. This beam has both sensing and actuating PVDF layers. The sensing layer detects the deformation signal due to an external micro-force acting at the sensor tip. Using a LQR optimal feedback control scheme, a counteracting bending moment is generated by the actuating layer, balancing the deformation of the sensor beam. The sensor tip will then maintain the equilibrium position as though the sensor stiffness is virtually unproved, yielding accurate motion control of the sensor tip. Furthermore, the micro-force value can be obtained by calculating the balance force generated by the counteracting servo voltage applied to the actuating layer. Experimental results verify both the performance of the active micro-force sensor and the effectiveness of the models. © 2005 IEEE.