應用於微微衛星之先進微型陀螺儀原型設計與製作計畫

Abstract

本計畫以太空微微衛星轉速測定為研究方向，陀螺儀則是一般測量物體轉速常使用的慣性感測元件之一。由於衛星上所使用的各式元件對於元件的尺寸、重量、可靠度、消耗功率、太空嚴苛環境承受度和使用年限等，皆有其特殊的設計考量，工業用之陀螺儀並無法滿足衛星需求。因此，本計畫以微機電系統（Micro Electromechanical Systems，MEMS）技術設計製作一適用於衛星轉速測定之微陀螺儀，其主因即在於利用MEMS技術製作之元件具有體積小、重量輕、消耗功率低等優點。本計畫所設計製作之微陀螺儀元件將包含：微結構與微感測電路二部分。於微結構部分，計畫初期將分析現有各式微陀螺儀感測原理及其優缺點，選定一衛星適用之感測原理，並進行微機電製程可行性評估，其次根據微製程設計規範與衛星對於元件之設計需求，針對微結構之外型與尺寸進行初步設計，並且推導分析微陀螺儀之動態方程式，進而修正各項結構參數，以符合所需之動態特性。接著藉由微機電模擬軟體輔助，進一步分析結構之動態特性，與理論推導做一相互驗證，最後再進行微結構實際製作與特性量測，驗證製程可行性。於微感測電路部分，初期將依據選定之元件感測原理與微結構參數，以電路模擬軟體輔助設計所需之感測電路，並以現有之被動元件與OP等電子零件，以PCB板實現感測電路，驗證感測原理可行性，最後再以ASIC設計方式，製作一適用與此微陀螺儀之訊號處理與驅動電路IC。

An angular-rate sensing device namely micro-gyro for pico-satellite is under investigated in the present project. Due to the special design considerations such as size, weight, reliability, power consumption and harsh space environment for the angular-rate sensing device of pico-satellite, traditional gyro cannot meet the above-mentioned requirements. Therefore, in the present project, we plan to use the MEMS technology to design and manufacture a micro-gyro for its advantages in small size, light weight, and low power consumption. The present project consists of two aspects in designing and manufacturing of micro-gyro: microstructure and micro-sensing circuit design. The initial phase of this project will concentrate on studying and analyzing the advantages and disadvantages of existing micro-gyro with suitable sensing principle and manufacture processes in mind. According to the sensing device design requirements of pico satellite and process specifications, a prototype of microstructure for pico satellite along with corresponding dynamic equations are obtained. By using these equations, we are able to modify individual structural parameters that can be used to satisfy the design dynamic characteristics. Furthermore, a MEMS oriented software simulation program is used to justify the derived dynamic equations. The microstructure will be fabricated to verify its characteristics and corresponding process. By using circuit simulation software along with chosen sensing principle and microstructure parameters, we are able to design micro-sensing circuit. At the present phase, we will realize and verify the sensing design using PCB and existing passive components and OP. The final signal processing and driving circuit design for pico satellite will be carried out using ASIC.