| On-orbit operations mainly consist of space station construction, spacecraft maintenance andrepairas well as the military offensive and defensive missions. With the development of science andtechnology, space manipulator is playing an increasingly significant role in the on–orbit operations ofspacecraft and gradually becomes an important research direction in the technical field of on-orbitoperation.In this dissertation, the problem of impact/contact between space manipulator end-effectorand the target object are discussed.First of all, the research status of on-orbit operations, technical tracking and research directionare introduced. A specific application of manipulator is presented to illustrate its indispensable role inthe development of on-orbit operations and the national basic industries. Also, the paper introducesspace manipulator operation mode, kinematics, dynamics model and the idea of the virtualmanipulator.Second, the paper concentrates on Hertz contact theory to establish dynamic model of contact/impact. Considering the feature of impact/contact between space manipulator end-effector and thetarget object, the paper establishes dynamic model of impact/contact of the space manipulator to dealwith the contact force and the velocity of the space manipulator end-effector. In addition,impact/contact and friction are nonlinear phenomena, which lead to the dynamics model of the spacemanipulator is nonlinear. In order to accelerate the simulation and reduce system resource, the paperpresents a reduce-order-model of the dynamic model of manipulator and validated by simulation.Finally, based on the idea of virtual manipulator, the center of gravity vectoris established. Thedynamic equation of impact/contact is presented with the consideration of nonlinear friction betweenthe end-effector of manipulator and the target object. Also, the paper calculates the contact force andthe velocity of the end-effector of manipulator using the dynamic equation built on before. |
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