| The dynamics coupling problem of satellite platform and flexible annex is alwaysconcerned in the field of satellite attitude control, and has not been completely resolveduntil now. In the past, the flexible annex and satellite platform were fixed together. Itrequired more design of controller to resolve the interaction. But it is not suitable for thelarge flexible antenna. This dissertation referenced the theory of coupling-reductioncontrolling, designed the control system of decoupling-mechanism, connected thesatellite platform and flexible antenna by the decoupling-mechanism, and controlled thesupport arm of antenna in the mechanism. The design of the decoupling-mechanismaimed to reduce the interaction between the satellite platform and antenna, improve theaccuracy of the satellite attitude control and the pointing of antenna control, suppressedvibration of the antenna as much as possible.Firstly, the dissertation researched the development and present situation of theflexible antenna and the satellite attitude control, and researched the development andapplication of the rotary transformer which is acted as the measuring element and thevoice coil linear motor which is acted as the actuator in the control system ofdecoupling-mechanism. The dissertation also modeled some parts of the control system.Secondly, the dissertation has designed the control system of decoupling-mechanism according to the model. The control system has two loops, and chose thePID control method. The inner loop which is the velocity loop has a high bandwidth tosuppress friction torque. The outer loop which is the position loop has a low bandwidthto isolate the natural frequency and to suppress the vibration of the antenna so that thesatellite antenna has a higher pointing accuracy. The dissertation simulated the controlsystem using Matlab software.Thirdly, the dissertation improved the control system according to the defect. Thedissertation designed two groups of the PID parameters instead of one group, and whichgroup will be selected is up to the actual situation so that the system has moreself-adaptibility. The dissertation confirmed the feasibility of the decoupling-mechanismcontrolling and all performance indexs meet the requirement according to the simulationof Matlab software.Lastly, the dissertation designed the control system of decoupling-mechanism bythe hardware and software. The control system measured the angular position and theangular velocity of the rotating axis of the decoupling-mechanism by the dual-channelrotary transformer, and controlled the rotation of the rotating axis by the swing voicecoil linear motor. The system controlled the decoupling-mechanism by the circuit boardof angular measuring and delivering and the circuit board of motor controlling andprovided the necessary condition to the coupling-reduction controlling of satelliteplatform and antenna. The dissertation researched and designed the control system ofdecoupling-mechanism and confirmed the feasibility of the decoupling-mechanismcontrolling. The accuracy of antenna pointing control and the accommodation time ofthe step signal instruct met the requirement. |
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