SPS 大型パネルアンテナ面精度維持のための基礎実験

摘要

A very large deployable antenna panel that consists of antenna elements, microwave circuits, control and power circuits and power generation devices is a major portion of the Solar Power Satellite (SPS). Heat cycle on the orbit will cause a distortion of the antenna panel of the SPS and result decrease of power transmission efficiency. Therefore, it is necessary to maintain the flatness of the panel. On the other hand, a famous 2-D deployment method called "MIURA ORI" cannot be used for the panel because it has thickness. So, we have been studying a reliable 2-D deployment and a maintaining method of the flat surface that utilizes a smart actuator. The smart actuator consists of the shape-memory alloy (SMA) and a controller. We carried out the deployment experiment using the smart actuators. We made a four panel trial system for one dimensional experiment in order to confirm a basic function of the smart actuator. In this experiment, the flatness was set within ±5 °. Two types of the SMA coil with open angles of 140° and 220° were processed by shape-memory treatment with heat. Fatigue property of the processed SMA was evaluated. It was confirmed that the SMA coil can be used for the panel deployment experiment. The angle control system that consists of the LED, the light-receiving device and a control circuit were made and evaluated.