Coordinated Control Techniques Of Orbit And Attitude For Micro-Satellite Formation Flying

The micro-satellite formation flying is the research focus in the field of aerospace over the pastdecade. It has broad application prospects. There are mainly three coordinate strategies for themulti-agent formation, that is, the leader-following method, the behavior-based method, and thevirtual structure method. The orbit and attitude coordinated control law of the satellites are designedseparately used two methods. The formation configuration keeping control, formation maneuveringcontrol, and attitude coordinated control are achieved. But the dual quaternion algebra can describethe orbit and attitude model with a unified form. And the orbit and attitude coordinated control can bedesigned together, which has better advantages in the field of the spacecraft dynamics modeling andthe control application. The main research content and innovative results are as follows:(1) The relative motion theory of the satellite formation flying is analyzed. The relative orbitaldynamics model is established, and the condition of the formation flying-around is given. The attitudeparameters are described in detail, and the advantages and disadvantages are compared. The relativeattitude kinematics and dynamics model are established based on the quaternion method.(2) The leader-following method is used to study the formation cooperative control problem.Taking two satellites formation as the example, the LQR cooperative control law for the orbit is given,and the stability of the system is analyzed. The simulation validates that the following satellite canmaintain the formation relative to the lead satellite under the interference. The leader-followingformation with one leader and two following is used. The coordinated attitude control which containsthe following attitude and the relative attitude is given. During the leader achieve the desired attitude,the following track the leader attitude and achieve the desired attitude finally. The coordinated attitudecontrol for the following and the formation is realized. Analying the effect of the control parameterson the attitude coordination, and the coordinated control law should not be used in the case of stronginterference.(3) A coordinated control method used the virtual structure is given. The method treats the entireformation as a virtual rigid body for the control or maneuver. The formation configuration is keptduring the maneuver. Taking three satellites formation as the example, the dynamics and kinematicscontrollers for the virtual structure are designed. Dynamics controller with formation feedbackrealizes the control of formation velocity. Attitude sliding mode controller is presented with externalinterference. The simulation of the virtual structure with formation feedback and without feedback is compared. The results show that the virtual structure without formation feedback, the formation cannot keep the original configuration well. But with the formation feedback, the error is smallersignificantly, and the convergence speed is faster. And the formation is maintained during themaneuver.(4) The dual quaternion is applied to study the problem of micro-satellite formation flying. Dualquaternion is proved to describe the rotation and translation of the rigid body motion complete from ageometric point and achieves the coordinate transformation. The attitude kinematics and dynamicsequation of a single satellite are established based on dual quaternion, and on this basis, taking twosatellites formation as the example, the relative kinematics and dynamics model are derived.(5) A cooperative control method based on dual quaternion is given. The information consensustheory is applied to the control problem of the formation flying. The cooperative control law isdesigned using the dual quaternion. The synchronization and tracking control of the position andattitude for the four satellites are simulated. The results show that the synchronization and tracking ofthe position and attitude can be achieved within500seconds.(6) An embedded simulation platform for the satellite formation is designed. The satellites in theformation are simulated by four PC104systems. The satellite mission scheduling process of thesystem is given. The system can be used to verify the formation control algorithms and develop thesatellite management software.