衛星磁場探測儀(MFI)無磁展開機構研發

Abstract

本研究專題「衛星磁場探測儀(MFI)無磁展開機構研發」係自國內發展太空科技以來，首次完全由國內自行研發之衛星科學酬載機構。研究範疇包含功能需求及規格訂定、機構設計、機構製作至最後測試驗證等。 不同於國外一般僅提供衛星方位訊號參考之磁位計，本論文研究之磁場探測儀需要偵測太空中之微弱磁場擾動變化(小至0.1nT)，故機構開發時需要以較高之磁淨度、高剛性及高可靠度等為考量，才能確保機構能夠達成其功能需求。 本研究機構包含幾項關鍵性零組件，皆有其設計之特別考量，如電位計之設計需考量無磁性及使用乾式軸承，轉動機構及阻尼器需要無磁性、無真空洩露、無電源輸入、高可靠度及高剛性等，伸臂設計需質輕及高強度，感測器固定座要求耐熱衝擊、耐高溫、電絕緣特性及不導磁，解鎖(鎖住)機構設計為提高MFI機構振頻而使用固鎖狀態強度較高之滑銷解鎖設計等。若MFI通過實際太空環境考驗及功能測試，其所使用之關鍵組件及設計理念，爾後將可以客觀的應用於各類型之衛星酬載機構。 針對本研究專題所建立之MFI機構雛型件，分析其伸臂鎖住狀態及展開狀態，其自然振頻分別為286.939Hz及41.808Hz，其中鎖住狀態能滿足140Hz之規格需求，而展開狀態振頻值雖比規範值50 Hz小，但依據MFI模型振頻模擬分析經驗，將來只要改變伸臂與轉動機構之材質，則必定能滿足其規格需求。 藉由本論文之MFI機構研發經驗，建立衛星酬載機構研發模式及技術，可作為國內發展相關衛星裝備之參考依據，以提升衛星科技發展之自主性。

This research topic “The Research and Development of a Non-magnetism Deployment for Magnetic Field Instrument (MFI) of Satellite” is related to the first payload mechanism of satellite which is thoroughly researched and developed domestically since space technology burgeons in Taiwan. The research domain comprises functional requirements, specification set-up, mechanism design, fabrication, final testing and certification. Different from foreign magnetic potentiometers which merely provide signals regarding satellite position, the magnetic field Instrument in this research needs to detect weak magnetic field disturbances (small to 0.1nT) in the space. As a result, higher magnetic purity, high rigidity, and high availability should be taken into consideration when developing the mechanism, in order to assure it can meet the functional requirements. The development mechanism comprises several critical components all of which have respective special consideration in design. For instance, in respect of the design of potentiometer, it needs to consider non-magnetism and utilization of dry bearings; with regard to the design of rotation mechanism, Hinge and Damper, it requires non-magnetism, no vacuum leak, no power input, high availability and high rigidity; the design of Boom should be of light material and high intensity; the design of Sensor Frame requires thermal shock resistance, high temperature resistance, electrical insulation and no magnetic conductivity; the design of unlock/lock mechanism adopts the pin-puller with higher intensive locking status in order to resonant vibration frequency of MFI mechanism. If MFI can pass practical tests in the space environment and other functional tests, its key components and design philosophy can be objectively applied to various types of satellite payload mechanisms in the future. Based on the initial model of MFI mechanism developed in this research, the natural frequencies both for the locked and deployed status were 286.939Hz and 41.808Hz respectively. Boom Locked Status could meet the specification requirement of 140Hz. Although the frequency in the deployment status was below the standard of 50Hz, however the specification requirement will be satisfied in the future through changing materials of boom and rotation mechanism. Experience acquired in the research and development of MFI deployment mechanism in this dissertation, can be applied to the future development of the satellite payload system, enchance Taiwan’s satellite related technology, and reduces Taiwan’s dependency on the foreign technical supplies.