| The Combination Body of Micro-nano Satellites(hereinafter referred to as CBMS)is a kind of spacecraft which is formed by adsorption and aggregation of cubical micro-nano modules by magnetic connectors.It can reconfigure through the motion of the modules under constraint of the magnetic hinges.This kind of spacecraft can be used in the field of expansion and transformation of large space antenna arrays due to its capability of reconfiguring on orbit,so it has high research value.As a new type spacecraft,CBMS has many key technical problems to solve.To study the technical problems,the following work is completed in this paper.The dynamic model of CBMS is established.The dynamic simulation of the process of reconfiguration is completed based on the dynamic model.The simulation includes the attitude motion of the main body under symmetrical reconfiguration defined in this paper and the change of the internal force at the hinge during reconfiguring.The above two parts of study provide theoretical basis for the following research of symmetrical reconfiguration planning algorithm and compliance reconfiguration control.The symmetrical reconfiguration planning algorithm of CBMS is studied.On the basis of A*algorithm,considering the constraints of module motion,introducing the optimal assignment metric and coincidence degree metric as the index of evaluation function in A* algorithm,the configuration planning algorithm which can realize parallel movement of multiple modules is designed.In order to increase the proportion of symmetrical reconfiguration steps,and to reduce the influence of reconfiguration on the attitude of the main body,the judgement of symmetrical reconfiguration is introduced into the planning algorithm.Finally,the effectiveness of the algorithm is verified by different calculation examples.The compliance reconfiguration control of CBMS is studied.The fuzzy control is chosen as the control method,and the fuzzy control law of reconfiguration is designed.In order to reduce the internal force at the hinge,the fuzzy control algorithm is improved,and a fuzzy regulator of quantization factors is designed.In the end,the simulation analysis of the reconfiguration under the control of the improved controller and the original controller is carried out to verify the effectiveness of the improved control method.Finally,a set of verification platform is designed and built to demonstrate the reconfiguration process in the horizontal direction by using the 3 DOF plane air bearing platform.The verification platform also demonstrates the function of the suspended gravity unloading device and the control system of the prototype of CBMS,which lays a foundation for the reconfiguration control in the vertical direction when gravity unloaded. |
