Atttiude Estimation for Small, Agile Spacecraft

非常小的航天器越来越被视为具有成本效益和反应灵敏的空间任务的有效平台。曾经被认为只适用于技术演示的立方体卫星和纳米卫星级航天器现在在苛刻的环境中具有重要的飞行遗产。随着这些航天器能力的扩展，设计人员要求卫星子系统具有更好的性能。这种对改进性能的推动在航天器姿态估计领域尤为突出。***本建议探讨在设计用于非常小的航天器的传感器和综合姿态估计系统时遇到的挑战。这些任务不仅需要精确的航天器方向知识，而且许多新兴的地球观测（EO）卫星服务应用，以及低地球轨道（LEO）以外的任务都需要在卫星经历快速运动时获得这种姿态知识。要适应这些技术和操作上的挑战，就需要采用与传统卫星工程截然不同的设计方法。提出的研究结合了设计贸易研究与单传感器和多传感器估计系统的详细分析。拟议的研究计划依赖于若干互补的方法。高级模拟用于进行系统级贸易研究和设计优化。首先对更详细的传感器处理和估计技术进行了分析评估，然后使用Matlab和Zemax对传感器运行进行了详细的仿真验证。新的处理算法可以在各种工程模型星跟踪器和激光雷达系统的实验室实验中进行评估和测试。这种全面的开发和验证方法有助于成熟的创新，使它们适合与行业合作伙伴一起进行后续项目。***我们期望这项研究将为敏捷立方体卫星和纳米卫星的高性能姿态估计实践带来改进。这些进步将使任务设计者（更好的贸易研究和设计工具）、姿态确定和控制工程师（量身定制的估计和信号处理算法）以及航空电子开发商（运动补偿和其他传感器特定创新）受益。********

Very small spacecraft are increasingly seen as a valid platform for cost-effective and responsive space missions. Once considered suitable only for technology demonstrations cubesat and nanosatellite class spacecraft now have significant flight heritage in demanding environments. As the capabilities of these spacecraft expand, designers require better performance from the satellites' subsystems. This push towards improved performance is particularly acute in the area of spacecraft attitude estimation.***This proposal examines the challenges encountered in designing sensors and integrated attitude estimation systems for very small spacecraft. Not only do these missions demand precise knowledge of spacecraft orientation but many emerging applications for Earth-Observation (EO) satellite servicing, and missions beyond Low Earth Orbit (LEO) require that this attitude knowledge be available when the satellite is undergoing rapid motion. Accommodating these technical and operational challenges requires design approaches significantly different than what is encountered in traditional satellite engineering. The proposed research combines design trade-studies with detailed analysis of single-sensor and multi-sensor estimation systems. ***The proposed program of research relies on a number of complementary methodologies. High-level simulations are used to conduct system-level trade studies and design optimization. More detailed sensor processing and estimation techniques are first evaluated analytically and then validated with detailed simulations of sensor operation using Matlab and Zemax. New processing algorithms can be evaluated and tested in laboratory experiments on a variety of engineering-model star trackers and LIDAR systems. This comprehensive approach to development and validation helps mature innovations to the point that they are suitable for follow-on projects in conjunction with industry partners.***We expect that this research will lead to improvements in the practice of high-performance attitude estimation for agile cubesats and nanosatellites. These advances will benefit mission designers (better trade studies and design tools), attitude determination and control engineers (tailored estimation and signal processing algorithms), and avionics developers (motion compensation and other sensor-specific innovations).********