Design, Development and Implementation of the Position Estimator Algorithm for Harmonic Motion on the XY Flexural Mechanism for High Precision Positioning This article presents a novel concept of the position estimator algorithm for voice coil actuators used in precision scanning applications. Here, a voice coil motor was used as an actuator and a sensor using the position estimator algorithm, which was derived from an electromechanical model of a voice coil motor. According to the proposed algorithm, the position of coil relative to the fixed magnet position depends on the current drawn, voltage across coil and motor constant of the voice coil motor. This eliminates the use of a sensor that is an integral part of all feedback control systems. Proposed position estimator was experimentally validated for the voice coil actuator in integration with electromechanical modeling of the flexural mechanism. The experimental setup consisted of the flexural mechanism, voice coil actuator, current and voltage monitoring circuitry and its interfacing with PC via a dSPACE DS1104 Ru0026D microcontroller board. Theoretical and experimental results revealed successful implementation of the proposed novel algorithm in the feedback control system with positioning resolution of less than xc2xb15 microns at the scanning speed of more than 5 mms. Further, proportionalintegralderivative (PID) control strategy was implemented along with developed algorithm to minimize the error. The position determined by the position estimator algorithm has an accuracy of 99.4% for single direction motion with the experimentally observed position at those instantaneous states.

Visionbased magnetic platform for actuator positioning and wireless control of microrobots This work presents a method to guide microrobots by positioning a magnetic actuator using hybrid vision system. The used actuator mounted at a robot endeffector creates local maxima of the magnetic field magnitude, which results in an attractive point for microrobots in its influence zone. The hybrid vision system serves to control the actuator position through the robotic platform to make the trapped microrobot undergo a planned trajectory. In first validation results, the particle driving is achieved in open loop with no adjustment with respect to the planned trajectory. Such scheme can be used in the case where the microrobot position can not be measured in real time. The second validation results deal with the case of microrobot positioning by visual servoing. This can be used in the case where recovering microrobot position is possible, for example in eye treatment.