부산대학교 도서관

During the operation of space manipulators for debris removal, the obstacles moving in the workspacemust be avoided. We propose a unified modelling framework for multiple moving obstacles and a collision-freetrajectory planning method for a redundant space manipulator. The complete properties of an obstacle, including itsshape, dimension, pose (position and orientation), and velocity (linear and angular), are defined in the model. Theobstacle surface is represented by a super quadratic function whose parameters are adjusted to describe differentshapes and dimensions. Pseudo-distance is defined to evaluate the proximity extent between the manipulator andan obstacle. Considering multiple different obstacles, we present an approach to normalize the pseudo-distances. The self-motion of the redundant manipulator was used to optimize the normalized pseudo-distance by adaptiveredundancy resolution. By ensuring that the pseudo-distance was always larger than the safety threshold value,collisions with the obstacles were avoided. The proposed method solved the problem for which the Euclideandistance was difficult, or even impossible, to calculate for 3-D cases. When handling multiple different obstacles, theproposed method was much easier and had higher computational efficiency than previous methods. The proposedmethod was verified by the simulation of typical missions.