Design and analysis of an actuator/position sensor for microgravity vibration isolation

Abstract

An actuator/position sensor was desired for Micrographics. microgravity vibration isolating. The actuator is to be used as a successor to the actuator used in the current microgravity vibration isolation system develop by NASA, Marshall Space Right Center. Some of the actuate specifications were reevaluated initially to make them more appropriate for the particular application. Based on the actuator used in the previous system, a preliminary design was performed by using an analytical model. 'then the design was fine-tuned by utilizing unite element simulations to model the actuator magnetic held. A revised actuator design was made to overcome the shortcomings of the preliminary actuator design recognized during the design analysis. The revised actuator design was also desired to allow integration of a position sensor into the actuator. An engineering unit of the actuator/position sensor was fabricated and characterized experimentally. The experimental results showed improved characteristics of the actuator, especially its reduced output positive dependence. As for the position sensor, the problem of cross-axis sensitivity was recognized, but a scheme was devised to compensate this undesirable characteristic to some degree.