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Control Strategy Of The Satellite Platform Considering The Dynamic Characteristics Of Flywheel And Imaging Performance Analysis

Posted on:2017-05-01Degree:MasterType:Thesis
Country:ChinaCandidate:P Z ZhangFull Text:PDF
GTID:2272330503458412Subject:Aeronautical and Astronautical Science and Technology
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The optical remote sensingsatellite platformvibration during the camera exposure time will produce relative motion between the subject image and the photosensitive medium,which causes image shift, and further lead the imaging blur. So how to achieve highprecision and stability control applied to the satellite platform andhow to establish a reasonable and effective analysis of imaging performance evaluation indicatoris practical engineering significance.In this background, firstly, this paper establish a dynamic model of the satellite platformwith flexible attachment using Kane method, and it also consider the friction effect and the static and dynamic unbalance vibration phenomenon of the reaction flywheelin the actual operation of the process. By comparing the dynamic characteristics Stribeck static model, Dahl LuGre dynamic model and dynamic model of the reaction flywheel, LuGre model is adopted because it can describe the actual friction behavior more comprehensively.Static and dynamic unbalance model is built by the method of equivalent mass, which describes the unbalanced torque vibration frequency associated with the speed of the flywheel.Secondly, an Active disturbance rejection control(ADRC) is applied to the satellite platform system with reaction flywheels, which is not rely on accurate modeling parameters and has strong robustness. It willtrack signalquickly without overshoot by the Tracking Differentiator(TD),compensateinterference output dynamicly by theExtended State Observer(ESO)and output control torqueby the Nonlinear State Error Feedback law(NLSEF). Meanwhile, in order to improve the control gain parameters, fuzzy tuning method is proposed by drawing theFuzzy Control thought. The simulation shows the contrast and verify that the fuzzy tuning has better control effect.Finally, the Modulation Transfer Function(MTF) is used as an optical imaging system performance evaluation indicator. The paperanalyzes the influence of the lateral vibration on the MTF theoretically. The simulation shows the effect of satellite platform vibration on the image shift and MTF of the imaging system, and draws conclusions that Fuzzy Active Disturbance Rejection Control(FADRC)has better imaging performance.
Keywords/Search Tags:Friction, Static and dynamic unbalance, Vibration, Active disturbance rejection control(ADRC), Fuzzy Active Disturbance Rejection Control(FADRC), Modulation Transfer Function(MTF)
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