The Research On Satellite Attitude Control System Diagnosis Based On Clusterign Analysis

The Fault Diagnosis Technique (FDT) applied to satellite systems is a special technique adopted to ensure the proper functions of the systems. It can not only realize the intelligent repaire, but the diagnosis experiences can also optimize the observation points of the satellite systems. With the developing tendency of more complex and intelligent of satellite systems, FDT plays a more important role and is pushed to reach a higher level.Because of the complexity of the modern satellite systems, the model-based FDT, which has a complicated modeling process and poor flexibility, can not always obtain a good result of fault diagnosis; while the cluster-analysis-based on history process data FDT (CBHD-FDT), which makes use of historical data and does not need the physical structure of systems, can overcome those short comings. Therefore, the research in this paper is using the CBHD-FDT, and exploring and applying the historical data gathered by the satellite monitering system. The main content of this research is as follows:Firstly, the characteristics of the extraction method into the data distrubuted features of CBHD-FDT are taken into deep research. Then two kinds cluster analysis algorithms are studied, using which the expected fitting data and the actual abnormal data are analyzed, a variance model is built, and the initial CBHD-FDT model is established.Then, the numerical simulation is performed on a standard aircraft control system, from which both the healthy and faulty data are obtained. Further, CBHD-FDT is applied to diagnose this system, based on the results of which, the modeling process and diagnosis reasoning steps can be improved.What's more, combined with the actural structure of the satellite attitude controling system, the mathematical models of the main components are analyzed in details, with the influence of the flywheel friction torque on the attitude angle controling effects. The analytical models of the external disturbance forces and torques loading on the satellite attitude controling system are established. In addition, in view of specific operating and measuring components, the corresponding mathematical models are set under different faulure modes.Finally, based on several typical failure modes of a satellite attitude controling system, after the parameters of the simulation models and the state-observation points of the system are set, the simulation model is to be built in SIMULINK. From the running of the simulation, both healthy and faulty data of the system can be gathered, and CBHD-FDT is applied to perform the fault diagnosis of this controling system.