Research On Motion And Mission Planning Methods For On-Orbit Servicing Space Manipulator

Manipulators play an increasingly important role in the on-orbit service(OOS) due to its efficiency and lower cost. Studies on OOS are gradually focusing on free-floating space manipulator attribute to the lower fuel-consuming and longer life.Five key technologies including the kinematic modeling, motion planning, multi-objects task planning, obstacle-avoiding and comprehensive planning of space robot are studied in this paper supported by National863research projects, moreover, the results are simulated by Obiter to verify the methods proposed in this paper.The contents are as follows:(1) The development of space manipulator at home and abroad is investigated and space mission architecture and several typical tasks are introduced in the paper. The focal points of all kinds of space manipulator theories are described in detail.(2) Based on four assumptions, the space manipulator system is established, the generalized Jacobi matrix method and virtual manipulator theory are analyzed. In addition, A mutual-mapping method is proposed in the paper in order for less computation complexity and intuitive model.(3) Path planning algorithms of free-flowing space manipulator is studied in the paper, including point-to-point motion planning in joint space, point-to-point motion planning in Cartesian space and continuous path planning of space manipulator based on Cartesian space.(4) Based on the complexity of task tracing and on-orbit servicing, the on-orbit multi-objects task model is established, the non-linear subsection optimal algorithm is combined with the neighborhood searching algorithm on the multi-object task model to solve the multitask problems.(5) Different obstacles bounding boxes are established and the collision detection algorithm is proposed in the paper. Then, the obstacle-avoid problem is handled by position-attitude space subsection algorithm. Finally, a global obstacle-avoidance algorithm which based on Genetic Algorithm is proposed.(6) Eventually, All of the simulation results are demonstrated using Orbiter software, and a camera viewpoint mounted on the end-effector is simulated.The innovations are as follows: (1) A mutual-mapping approach is prpposed to advance the traditional generalized Jacobi matrix method. The results shows the more intuitive model and the less computational complexity.(2) In Cartesian path planning part, a dual-parameters method is proposed for the manipulator path planning., the iterative calculation of Newtown and Secant algorithm is used for high efficiency.(3)In the continuous path planning part, a subsection evolution algorithm is proposed to solve the general continuous path tracking problems, and also the non-differentiable and non-continuous path problems, the approach can also obtain the more flexible path.(4) The Genetic Algorithm is combined with the collision detection algorithm and the subsection evolution algorithm together because of the large base disturbance and more consume.