Atttiude Estimation for Small, Agile Spacecraft

非常小的航天器越来越多地被视为具有成本效益和反应灵敏的空间任务的有效平台。立方体卫星和纳米卫星类航天器曾经被认为只适用于技术演示，现在在苛刻的环境中具有重要的飞行传统。随着这些航天器能力的扩大，设计者对卫星子系统的性能提出了更高的要求。这一改进性能的努力在航天器姿态估计领域尤为突出。*本提案审查了在为非常小的航天器设计传感器和综合姿态估计系统方面遇到的挑战。这些飞行任务不仅需要航天器定向的精确知识，而且许多新出现的地球观测卫星服务应用，以及低地球轨道以外的飞行任务，都要求在卫星快速运动时能够获得这种姿态知识。应对这些技术和业务挑战需要与传统卫星工程中遇到的显著不同的设计方法。建议的研究结合了设计行业研究和对单传感器和多传感器估计系统的详细分析。*拟议的研究方案依赖于一些补充方法。高层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分析评估，然后使用MatLab和Zemax对传感器操作进行详细的仿真验证。新的处理算法可以在各种工程模型恒星跟踪器和激光雷达系统上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。*我们希望这项研究将改进灵活立方体卫星和纳米卫星的高性能姿态估计实践。这些进展将使任务设计人员(更好的贸易研究和设计工具)、姿态确定和控制工程师(量身定做的估计和信号处理算法)以及航空电子设备开发人员(运动补偿和其他传感器特有的创新)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).********