Research On Space Robot Arm Assembly Modeling And Visual Guidance Problem

As human activities in space become more frequent,space missions become more diverse,mission quality requirements become higher and higher,and the need to build large space vehicles is growing.However,due to the limitations of carrying capacity and research cycle,the scale of the spacecraft platform is difficult to expand,and the flexibility and scalability of space missions are difficult to effectively improve.In order to solve the dilemma of cracking,the working mode of spacecraft deformation and reconstruction in orbit is proposed.This mode assists in the assembly,morphing and maintenance of the spacecraft mainly through the space robot/mechanical arm.This thesis focuses on the above task background,combined with the practical problem of module assembly of large antenna satellites,and deeply studies the dynamic modeling and visual guidance of space manipulators,and validates the relevant methods through simulation.The work described in the paper includes the following aspects:Firstly,to meet the modeling problem of space manipulator,the paper discusses how to express the positive kinematics and inverse kinematics of the manipulator through the body coordinate system,with equations defining by joint variables.Then,this paper analyzes how the decoupling simplifies the inverse kinematics solution.On the basis of kinematics,the dynamic calculation process of the manipulator is discussed.Finally,the calculation method of the manipulator on the ground is applied to the space manipulator system.The influence of the motion and dynamic factors of the space manipulator on the position and attitude of the spacecraft base is analyzed.Secondly,how to determine the motion state of the manipulator's manipulating object during the movement of the manipulator is studied.The core of the problem of visual guidance is elaborated,and then the physical reasons of the camera imaging model and the distortion phenomenon in the imaging process are explained.Combined with the imaging characteristics in the space experimental environment,the feature extraction problem is discussed.The extraction method and matching scheme are proposed,which establishes the practical basis for the estimation of target motion.The last part is the verification of the first two chapters of modeling and algorithm.The simulation experiments of spatial manipulator dynamics modeling and image feature extraction matching are completed in two software development environments.The feasibility of the aforementioned theoretical method was confirmed.