Design and characterization of a linear micropositioner based on solenoid and compliant mechanism

This article presents the development of a linear micropositioner for a micro electrical discharge machine (mu EDM). A linear open-loop micropositioner was developed using a solenoid-flexural element architecture. The power system varies the force delivered by the solenoid using the technique of pulse width modulation (PWM). The capabilities of the micropositioner were evaluated by displacing a 1 kg mass over a 30 urn distance, and tracking its position with an linear variable differential transformer (LVDT) with a resolution of 0.5 mu m. Experimental data was collected using a data acquisition system developed in Lab-View. Results show that the micropositioner is capable of achieving accuracies that fall within the limits of uncertainty of the LVDT. The displacement behavior of the micropositioner presents hysteresis due to its electromagnetic constitution and the friction presented by the linear guides that support the working mass. The impact of the open-loop control parameters on the hysteresis of the micropositioner was evaluated over a series of consecutive controlled movements. (C) 2011 Elsevier Ltd. All rights reserved.