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

近年来，由于微机电系统（MEMS）和纳米技术的发展，微型卫星（10 kg~100 kg）和纳米卫星（1 kg~10 kg）经历了快速增长。然而，它们的科学和商业应用涉及几个具有挑战性的问题，包括MEMS传感器的显著的偏置不稳定误差，由磁力矩器提供的低姿态性能，纳米轮或控制力矩陀螺（CMG）仍处于发展阶段，以及编队飞行期间单个卫星和多个卫星的容错姿态控制不可用。拟议的研究将在三年的项目期间审查这些具有挑战性的问题，重点是三个目标： 1)纳米轮和CMG设计（第一年），2）控制器设计（第二年），以及3）容错和智能姿态控制（第三年）。第一个目标将涉及质量、功率和有效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。 第二个目标将涉及控制器设计的单颗卫星，和多颗卫星编队保持和重构。最后的目标将涉及在环境扰动（重力梯度、空气动力、地球磁力、太阳辐射压力等）的情况下，为包括欠驱动卫星在内的卫星开发容错和智能姿态控制。 最后，计划将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JC 2Sat（日本-加拿大联合合作卫星），并将在SpaceQuest Canada Inc.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.