著者

武田 真司 小出 紗英 大本 圭祐 坂本 啓 田中 宏明 石村 康生 大熊 政明

出版者

一般社団法人 日本航空宇宙学会

雑誌

航空宇宙技術 (ISSN:18840477)

巻号頁・発行日

vol.19, pp.151-158, 2020 (Released:2020-10-29)

参考文献数

10

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For the observation of microwave in space over 100 GHz by radio astronomical satellites, this study develops shape-deformable antenna reflectors. When a certain portion of the antenna reflector prototype is deformed, the entire reflector is affected by the partial deformation. The purpose of this study is firstly clarifying the effect of coupling in reflector displacement. Secondly, this study tries the performance evaluation of hysteresis elimination by a piezoelectric strain feedback system under the effect of the displacement coupling. To achieve these objectives, this study quantifies the displacement coupling, the relations between piezoelectric strain and reflector displacement, and the residual reflector displacement error under the feedback control when multiple actuators are driven simultaneously. As a result, this study clarifies that there is a non-negligible coupling effect and the stress history dependence in the reflector surface deformation, causing the limit in the accuracy of the feedback system. Based on these experimental observations, this paper presents three design improvement plans that will possibly solve these problems.

著者

柏山 礼興 坂本 啓 田中 宏明 大熊 政明 石村 康生

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.863, pp.17-00566, 2018 (Released:2018-07-25)

参考文献数

15

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This study aims to develop an actively deformable space antenna system for radio astronomy around 100GHz. In order to reduce the thermal deformation in active control mechanisms composed of multiple materials, a method to cancel the mismatch of the coefficients of thermal expansion (CTE) is proposed and tested. The CTE mismatch between piezoelements and Super Invar structures is cancelled by adding another metallic part. For effective CTE cancellation, this study clarifies the cause of thermal deformation induced by the preloading mechanisms for a piezoelectric stack actuator. In addition, it shows the effect of the dimension tolerance of the piezoelements is significant, but still manageable by the proposed CTE cancellation method. The effectiveness of proposed method is validated by the use of finite-element analysis, prototyping models, and thermal deformation measurement experiments.