Review of Capabilities of a Linear Micropositioner Based on a Flexible Mechanism

This article presents the development of an actuator for micro electrical discharge machining (iEDM). A lineal micropositioner was developed using a solenoidflexural element architecture and an open-loop control configuration. The open-loop control system uses a personal computer (PC) connected to a microcontroller through an interface developed on language C and linked to the RS232 protocol. The system varies the force delivered by the solenoid using the technique of pulse width modulation (PWM). The capabilities of the actuator were evaluated by displacing a 1 kg mass over a 30im lenght. The position of the micropositioner was measured using a linear variable differential transformer (LVDT) with a resolution of 0.5im. Experimental data was collected by a data acquisition system developed in LabView. The results show that the actuator is capable of archiving accuracies that fall within the limits of uncertainty of the measuring system. A Design of Experiments (DoE) was used to evaluate the micropositioner performance. The displacement behavior of the actuator presents hysteresis due its electromagnetic constitution. The impact of each of the control parameters on the hysteresis behavior of the actuator was evaluated. An optimal control parameter combination that reduces hysteresis and magnifies displacement range is proposed.