KMS of Xinjiang Astronomical Observatory, CAS
| 大型射电望远镜主动面系统故障分析与容错策略 | |
| Alternative Title | Fault analysis and fault tolerant Strategy of active surface system for large radio telescope |
张丹清
| |
| Subtype | 硕士 |
| Thesis Advisor | 艾力·玉苏甫 |
| 2021-06-01 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Name | 理学硕士 |
| Degree Discipline | 天文技术与方法 |
| Keyword | 主动面系统 故障诊断 容错控制 最佳吻合 |
| Abstract | 随着射电天文学和大口径全可动射电望远镜的迅速发展，天文学家对于射电望远镜的性能要求也在不断提高，从米波、厘米波、毫米波到亚毫米波。根据RUZE公式可知更高的观测频率对射电望远镜主反射面的面形精度需求更高。目前主动面系统是最有效的主动补偿技术，这种技术可以补偿大型望远镜因自重、温度、热变形以及风力等环境负载产生的结构变形，从而满足望远镜在高频的天线效率。但由于主动面系统是一个有很多子系统构成的复杂系统，因此存在故障高发的可能，所以需要开发一套系统对主反射面进行故障诊断以及容错控制。该系统用于帮助望远镜操作人员找到望远镜主反射面的故障原因，反馈主动面系统的运行状况，并对特定故障给出容错策略。本文基于CORBA (Common Object Request Broker Architecture) 中间件和故障树推理建立大型射电望远镜主动面故障处理系统并结合该系统给出了一种针对于促动器故障情况下的容错策略。针对QTT (QiTai telescope)主动面系统在将来的实际应用过程中需要面临故障处理问题，本文首先介绍了当前国内外射电望远镜主动面技术以及容错控制的发展现状。随后基于望远镜故障诊断的主流的框架CORBA和智能专家诊断系统对QTT主动面故障诊断及其容错进行初步理论框架设计，包含分布式的特殊存储服务、智能诊断方法和故障树推理。最后提出一种促动器故障下的QTT主动面最优容错策略，在最佳吻合面的设计基础上，提出一种以故障促动器为拟合基准的故障容错方法，该方法根据望远镜主动面故障诊断系统得到望远镜主动面健康矩阵，结合传统最佳吻合面并利用梯度下降法计算拟合参数, 最终通过仿真软件对该方法进行验证和测试，从而证明促动器发生故障之后采取该方法可以提高望远镜主反射面面形精度。最后总结一下该论文主要的工作如下：1. 对望远镜主动面系统发生故障后的处理流程进行分析，初步设计一个基于CORBA中间件和XML文本传输的主动面故障诊断系统，实现射电望远镜主动面的状态监管和日志存储。在此基础上2. 针对QTT望远镜的主反射面的具体结构，在专家系统框架设计一种具体的故障树模型，结合推理机进行故障位置的定位和故障原因的判断。3. 设计一种适用于促动器故障情况下容错控制算法，使得望远镜在发生故障之后可以降效率工作，在保持故障促动器不用移动的条件下可以提高主反射面的面形精度，并在多个俯仰角验证该算法的有效性。 本文分析了主动面故障诊断和容错控制的实现方式，在现有的望远镜控制系统的框架上拓展主动面的故障诊断系统，并提出一种容错算法来解决促动器故障引起的主反射面面形精度下降问题，对未来使用更先进的智能故障诊断方法和对更多类型的故障进行容错打下一定基础。 |
| Other Abstract | With the rapid development of radio astronomy and large aperture all movable radio telescopes, the performance requirements of radio telescopes for astronomers are constantly improving, from meter wave, centimeter wave, millimeter wave to submillimeter wave. According to the rule formula, higher observation frequency requires higher surface shape accuracy of the main reflector of the radio telescope. At present, active surface system is the most effective active compensation technology. This technology can compensate the structural deformation of large telescope due to self-weight, temperature, thermal deformation, wind and other environmental loads, so as to meet the high frequency antenna efficiency of the telescope. However, as the active surface system is a complex system with many subsystems, it has the possibility of high incidence of faults, so it is necessary to develop a system for fault diagnosis and fault-tolerant control of the main reflector. The system is used to help the telescope operators find out the fault causes of the main reflector of the telescope, feedback the operation status of the main reflector system, and give fault-tolerant strategies for specific faults. In this thesis, based on CORBA (Common Object Request Broker Architecture) middleware and fault tree reasoning, a fault handling system for active surface of large radio telescope is established, and a fault tolerance strategy for actuator fault is proposed.Aiming at the problem that QTT (Qitai telescope) active surface system needs to deal with the fault in the practical application process in the future, this thesis first introduces the development status of active surface technology and fault-tolerant control of radio telescope at home and abroad. Then, based on the mainstream framework of telescope fault diagnosis CORBA and intelligent expert diagnosis system, a preliminary theoretical framework of fault diagnosis and fault tolerance of qtt active surface is designed, including distributed special storage service, intelligent diagnosis method and fault tree reasoning.Finally, an optimal fault tolerance strategy for QTT active surface under actuator fault is proposed. Based on the design of the best fit surface, a fault tolerance method based on actuator fault is proposed. According to the fault diagnosis system of telescope active surface, the health matrix of telescope active surface is obtained. Combined with the traditional best fit surface, the fitting parameters are calculated by gradient descent method, Finally, the simulation software is used to verify and test the method, which proves that the method can improve the shape accuracy of the telescope main reflector after actuator failure. The main work of this thesis is summarized as below1. Based on the analysis of the processing flow of the active surface system of the telescope, a fault diagnosis system of the active surface based on CORBA middleware and XML text transmission is designed to realize the status monitoring and log storage of the active surface of the radio telescope. on this basis 2. According to the specific structure of the main reflector of QTT telescope, a specific fault tree model is designed in the framework of expert system. Combined with inference engine, fault location and fault cause are determined.3. A fault-tolerant control algorithm is designed for actuator failure, which can reduce the efficiency of the telescope after failure, and improve the shape accuracy of the main reflector without moving the actuator. The effectiveness of the algorithm is verified in multiple pitch angles.This thesis analyzes the implementation of fault diagnosis and fault-tolerant control of active surface, extends the fault diagnosis system of active surface based on the existing telescope control system framework, and proposes a fault-tolerant algorithm to solve the problem of the main reflector surface precision decline caused by actuator fault, which lays a foundation for the future use of more advanced intelligent fault diagnosis methods and fault tolerance for more types of faults A certain foundation. |
| Pages | 51 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/4743 |
| Collection | 研究生学位论文 |
| Affiliation | 中国科学院新疆天文台 |
| First Author Affilication | Xinjiang Astronomical Observatory, Chinese Academy of Sciences |
| Recommended Citation GB/T 7714 | 张丹清. 大型射电望远镜主动面系统故障分析与容错策略[D]. 北京. 中国科学院大学,2021. |
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| 大型射电望远镜主动面系统故障分析与容错策（2656KB） | 学位论文 | 暂不开放 | CC BY-NC-SA | Application Full Text | ||
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