Study On Dynamic Modeling And Controlling Of A Satellite With A Architectrue Of Disturbance Free Payload

The high precision and stability of the satellites are of importance in many projects, especially for the high-precision observation and laser communication satellites, etc. Due to the micro vibration caused by the moving of the parts and structural deformation of satellites, the pointing precision and stability of the satellites will be reduced, so the vibration isolation should be imperative. The structure of a satellite with a architecture of disturbance-free payload is adopted to isolate satellite payloads from vibration sources in the physical structure, which will guarantee the pointing precision and stability of the payload attitude.In this paper, the main work is divided into three parts. First of all, understanding the difficulties and challenges of satellite vibration isolation technology by introducing the development of satellite vibration isolation technology, in order to further improve the performance of vibration isolation, this paper puts forward the concept of catamaran satellite, and the present development is introduced. Second, researching the satellite structure adopted in this paper, and the kinematics and dynamics model is established. Finally, completing the control system design for the satellite, the corresponding PID controller parameters are given, simulating the satellite control system by Matlab/Simulink, verifing the gesture features and vibration isolation characteristic of catamaran satellite.The satellite is divided into two parts, which are payload module and support module. Eight actuators provide maglev field to disconnect two parts. Control method is a kind of coordinated control strategy which consider payload more. Dynamic model of the satellite is divided into three parts, which are load platform dynamics model, body structural dynamics model and the relative location of the structural dynamics model. Before the design of the satellite controller, we should solve the three problems. The first problem is the equitable distribution of eight actuators between the load platform and the main satellite structure. From the geometric structure, the paper proposes a scheme to minimize static coupling between the force actuators. The second problem is the allocation of output control force to the eight force actuators. In this paper, according to the relative attitude model and the relative position model, we can obtain the relative pose matrix and relative position matrix in order to solve the problem of the allocation of control. The third problem is how to solve the coupling between the relative position control system and the attitude control system of the load platform. In this paper, the coupling between the control subsystem is eliminated by using the method of the force field being decomposed into the net force field and the net moment field. By solving the three problems, we can get the three-axis decoupling control system model of the satellite, it can be decomposed into three parts including that the load of the payload module attitude control system, the support module attitude control system and relative position control system.