Design of fault tolerant and intelligent attitude control subsystem for micro and nano-satellites

近年来，由于微电子机械系统(MEMS)和纳米技术的发展，微小卫星(10 kg~100 kg)和纳米卫星(1 kg~10 kg)发展迅速。然而，它们的科学和商业应用面临着一些具有挑战性的问题，包括MEMS传感器的显著偏置不稳定误差，仍处于发展阶段的磁力矩、纳米轮或控制力矩陀螺(CMG)提供的低姿态性能，以及无法对单颗卫星和多颗卫星进行编队飞行的容错姿态控制。这项拟议的研究将在项目的三年时间里研究这些具有挑战性的问题，重点是三个目标：1)纳米轮和CMG的设计(第1年)，2)控制器设计(第2年)，以及3)容错和智能姿态控制(第3年)。第一个目标将涉及质量、功率和可用扭矩的数学建模和优化设计，以及计算机模拟和实验室测试。第二个目标将涉及单颗卫星的控制器设计，以及编队维护和重新配置期间的多颗卫星的控制器设计。最终目标将涉及在存在环境扰动(重力梯度、空气动力、地球磁力、太阳辐射压力等)的情况下开发卫星的容错和智能姿态控制，包括驱动不足的卫星。最后，计划将所开发的姿态控制系统应用于加拿大航天局和日本航天局的联合项目JC2Sat(日本加拿大联合合作卫星)，并将在SpaceQuest加拿大公司设计的卫星上进行飞行测试。

Recently microsatellites (10 kg~100 kg) and nanosatellites (1 kg~10 kg) have experienced rapid growth due to development on micro-electro-mechanical systems (MEMS) and nano technologies. However, their scientific and commercial applications involve several challenging problems including significant bias instability errors of MEMS sensors, low attitude performance provided by magnetic torquers, nanowheels or control moment gyros (CMGs) still under developmental stage, and unavailability of fault tolerant attitude control for a single satellite and multiple satellites during formation flying. The proposed research will examine these challenging problems during three years of the project with a focus of three objectives: 1) design of nanowheels and CMGs (year 1), 2) controller design (year 2), and 3) fault tolerant and intelligent attitude control (year 3). The first objective will involve mathematical modeling and optimal design for mass, power, and available torque, and computer simulation and laboratory testing. The second objective will deals with controller design for a single satellite, and multiple satellites during formation maintenance and reconfiguration. The final objective will involve the development fault tolerant and intelligent attitude control for satellites including underactuated satellites in the presence of environmental perturbations (gravity gradient, aerodynamic forces, Earth magnetic forces, solar radiation pressure, etc.). Finally, it is planned that the attitude control system developed will be applied to JC2Sat (Japan Canada Joint Collaboration Satellites), a joint project between Canadian Space Agency and Japanese Space Agency, and will be flight tested on satellites designed by SpaceQuest Canada Inc.