Modeling And Control Based On The Single Joint Locked Space Manipulator

Space manipulator system has been successfully applied to the space station, spaceshuttle, space robot, etc., it has independent analysis ability ability and visualidentification ability, can perform accurate operation, it is set machinery, vision,dynamics, electronics and control disciplines as one of the high-end space equipment.Along with the advancement of china space station construction tasks, spacemanipulator has higher requirements about positioning accuracy and reachable range,thus,7degrees of freedom of the redundant space manipulator develop is a newdevelopment direction. Space manipulator completes scheduled space mission safelyand steadily, accurately and effectively, and space manipulator is able to complete thescheduled tasks with appropriate force in the location specified, need to control theforce and position component of space manipulator.In this paper, locking the third joint of7degrees of freedom of redundant spacemanipulator, then, forming a new type of space manipulator arm structure, taking thenew type space manipulator arm structure as the research object, and focused researchspace manipulator modeling, the contact force calculation and force and position hybridcontrol. This paper analyses and studies the movement of space manipulator based onkinematical, and discusses the relationship between joint angle and position of spacemanipulator in the kinematics and inverse kinematics problems. Through7degrees offreedom of the redundant space manipulator and single joint locking6degrees offreedom space manipulator structure research, constructs the related physical model,builts space manipulator D-H coordinate system, gives the method of solving the D-Hparameters, and to solve the D-H parameters. According to solve Jacobian matrixrealize the operation space and the joint space transformation of space manipulator.Propose calculation method of the contact force comes from the space manipulator endcontact with environment the performing ORU operation. A cylindrical ORU andconical ORU guide groove are designed. According to the contact model, usemathematics method to obtain the invasion depth between ORU and ORU guide.Considering the contact model between space manipulator with environment as springdamper model, taking the obtained invasion depth into the spring damper model will beable to calculate the contact force of space manipulator. Based on force and positionhybrid control principle of space manipulator and dynamic modeling of SimMechanics method, use Matlab-Simulink to build simulation system of6degrees of freedom spacemanipulator performing ORU operation. Then, use the obtained contact force of spacemanipulator as feedback input the simulation system, use feedforward control systemsimulation. Simulation results indicate control system is accurate and stable, the controlalgorithm is feasibility and effectiveness.Finally, this paper summarizes the research contents and make prospect for furtherresearch aimed at the limitation of the paper research. Space manipulator itself is a kindof intelligent robot, with strong ability and broad application prospects, and spacemanipulator system will get rapid development.