基于故障诊断技术的深空探测器姿态自主控制研究

Deep-space explorers operate for a long time in unknown and harsh environment of space. Theirs components, special theirs sensors and actuators will inevitably be faulty. If the fault can not be promptly and correctly detected, located, isolated, and tolerated by reconfiguring controller, then the attitude control system would be out of control. Consequently, the planned exploration mission will not successfully accomplish. Most near-Earth orbit spacecrafts have been deployed with the ability to execute a “safe” mode transition in which a detected anomaly results in the spacecraft deactivating all thrusters and postponing science activities until the situation is resolved by engineers at the ground station. This technique needs the operating data of components to be downloaded. Those data are then used to diagnose and identify faults in ground stations. If faults are detected, its corresponding fault tolerant controller is then reconfigured and uploaded to the satellite. Although this scheme has certain fault tolerant capability, there are two drawbacks: one is its poor autonomy and real-time, the other is its relying on the support of ground stations. Due to serious communication delay between deep-space explorers and the ground stations on earth, that fault tolerant control strategy is not applicable for deep-space explorers. To date, few investigations have been reported in the area of deep-space explorers fault diagnosis and tolerant. To improve the autonomy of the deep-space explorers’ attitude system, this project will investigate: 1) autonomous fault diagnosis approach without the support of ground stations, and 2) high reliable fault tolerant control scheme. This project aims to develop an independent intellectual property right of deep-space explorer autonomous fault diagnosis and fault-tolerant technology. Furthermore, its engineering application will be investigated for deep space exploration.

深空探测器长时间运行于未知的、环境恶劣的太空中，其部件特别是敏感器与执行器将不可避免地产生故障。若故障不能被及时、正确地检测、定位、隔离并进行控制器重构，则姿态控制子系统将失效，从而使整个探测任务失败。目前多数近地轨道航天器采用数据下载至地面站进行离线诊断，然后重构控制器上传至航天器这一策略来处理故障。该技术手段在实际应用中遇到的“瓶颈”问题是：姿态控制自主性、实时性差，并且严重依赖地面站的支持。由于深空探测器与地面站之间存在严重的通讯时延，因此该技术手段对深空探测器而言，其工程应用价值低。迄今深空探测器故障处理方法鲜见报道，为此本课题将研究：1）脱离地面站支持的深空探测器自主故障诊断新方法，2）高可靠性、高安全性的姿态容错控制新策略。本课题将开发具有自主知识产权的深空探测器自主故障诊断与容错技术，并探索其深空探测工程应用。

长时工作于深空的探测器其执行器易发生故障。若深空探测器不能及时处理此故障，则其姿态控制系统的性能将被削弱，严重时系统可能不稳定，从而致使任务失败。为解决此问题，目前绝大多数的故障处理策略均依赖于地面站，从而导致执行器故障下的深空探测器姿态控制系统自主性差。为此，本项目应我国深空探测器高性能、高可靠性姿态控制控制系统设计的总体要求，对“姿态自主容错控制”的关键技术展开攻关。本课题聚焦于基于数据驱动的深空探测器部件故障诊断、设备级故障自主处理方法与探测器三轴姿态可控性评估、欠驱动探测器姿态容错控制与过驱动探测器姿态容错控制等四个主要研究内容，并进行了较为深入的研究，最终提出了一系列脱离地面站支持的深空探测器自主故障诊断方法与高可靠性、高安全性的姿态容错控制方法。较为深入地解决了基于数据驱动的探测器部件级故障诊断问题”、“欠驱动探测器姿态机动轨迹规划问题”与“多约束、多目标非线性系统冗余执行机构控制分配问题”等三大关键科学问题，实现了本课题既定的研究目标。项目执行至今，共发表学术论文26篇，授权发明专利5项，其中在IEEE Transactions系列期刊上发表论文11篇，会议论文13篇。所取得的研究成果获上海市技术发明一等奖项、辽宁省科学技术进步三等奖与锦州市科学技术进步一等奖各一项。此项目研究成果将为提高深空探测器姿态控制系统特别是执行器故障时的高可靠设计能力提供一定的理论方法支撑。