Stewart Platform with Low Thermal Expansion and Low Thermal Conduction Elastic Hinges for Precise Pointing Control

抄録

We proposed a pointing control technology for large support structures to meet demands for higher precision and larger size in the development of space observation equipment. A Stewart platform was adopted for the structure. As the linear actuator, we used a highly reliable artificial thermal expansion. To reduce heat transfer to structural members other than the actuator, we adopted an elastic hinge using an invar alloy called LEX-ZERO. The Stewart platform used in this study consists of six linear actuators and top/bottom plates which are connected by the elastic hinges. As a basic experiment, we conducted an experiment on the thermal insulation performance of elastic hinges. As a result of the experiment, about 97% of the heat flow from the artificial thermal expansion actuator could be cut off by elastic hinges. Then, 6 degrees of freedom control experiments were performed using the Stewart platform. As a result, it was possible to perform pointing control with excellent accuracy of within 1 μm in translational displacement and 2 arcseconds in rotational displacement.