Online Trajectory Regulation And Trace Control Of Satellite`s Rapid Attitude Maneuver

As the astronautical technology develops unceasingly, agile satellite with high observing accuracy and strong maneuver ability has been the research hot topic. Faced with the situation that the satellite are required to maneuver quickly and stably when emergent situation or task, the dissertation, this dissertation studied the fast attitude maneuver and stable object tracking problem of the agile satellite.Firstly, the thesis compared the advantages and weaknesses of the traditional slide mode controller and the hierarchy saturated PID controller. Then the hierarchy saturated slide mode controller was designed to obtain the attitude trajectory when the satellite rotated about the Euler axis. Simulation show that the proposed control method has good convergence ability and robustness. It can adapt to the circumstance when deviation occurs at satellite’s rotary inertia. However the attitude maneuver trajectory is not time optimal since the torque output of the attitude thrust are not saturated.Then the thesis deal with the above problem caused by the ineffectiveness of the control torque by control time switch method which has been successfully used in the control of the mechanical hand system with two link rods. Based on the assumption that the torque output by the controller were always saturated, the method could obtain the optimal maneuver trajectory just by solving the control torque switching time. Nonlinear regulate method was used to numerically calculate the accurate result with the quasi optimal trajectory former as the initials. Simulation was performed to show the method’s effectiveness and fast performance.The last section cover the attitude stability convergence problem during the agile satellite perform attitude maneuver. A non-singular fast terminal sliding mode controller was designed to satisfy the stable performance and convergent duration requirement. In order to improve the system’s adaptive and robust capacity, Chebyshev neuro-network method were applied to reduce the buffet of the controller resulting from the small interlayer in the sliding mode variable structure. Switch was added to the Neuro-network to make the controller can transform from the adaptive neuro-network controller and robust controller. Simulation shows that this controller can track the optimal maneuver trajectory gained above quickly and has strong robustness.