Research On Collision Analysis Method For Space Manipulator On Orbit

Space manipulator is an important tool for construction and maintenance on orbit, and plays a key role in extravehicular activity, cabin transfering and docking. With the development of space technology, intelligence and complexity of space manipulator’s operation task continues improving, which makes the possibility of collisions of space manipulator greatly enhance. Once collision occurs, mutations of joint speed may occur, which make space manipulator can’t reach the expected position and attitude. What’s worse, devices on manipulator may be damaged. Therefore, how to avoid the collision of space manipulator in time of taking execution has become the urgent problems in space manipulator application.The main content of this paper is about study on the method of collision and interference of on orbit space manipulator. This paper points out the existing problems of interference analysis technology based on a detailed analysis of all kinds of interference analysis algorithm, and presents a new method for space manipulator interference analysis. The method analyzes collision of space manipulator based on space manipulator’s collision and interference space. The current configuration of the space manipulator correspond to a list of joint angle, which determine the occurrence of interference between rods. Due to the interference analysis does not need to perform complex calculations, so it’s an efficient method, which means that it can not only ensure the safety of space manipulator motion, but also meet the real-time control of space manipulator.Firstly, the motion model of space manipulator is established. The kinematics model is set up according to the characteristics of space manipulator on orbit movement, then algorithm of linear path planning is designed, which is verified by a numerical simulation.Secondly, methods to analyze interference between the basic geometry are pointed out. Interference analysis of actual model of space manipulator needs a large number of complex calculations, which causes a large time, and it is not allowed in the actual operation. Usually we use the basic geometry that is slightly larger to replace the actual model, in order to improve the efficiency of detection. Space manipulator model can be simplified into sphere, cylinder, rectangular, convex polyhedron, or a combination of these geometry, therefore, this paper studies and realizes the interference analysis method between spheres, cylinders, rectangular and convex polyhedron, which lays the foundation for the realization of the space manipulator interference analysis.Thirdly, a method to analyze collision of space manipulator based on space manipulator’s collision and interference space is pointed out. Space manipulator is a connecting rod mechanism, and the linkage collision is determined in a particular configuration, which can judge the interference of the manipulator. Based on this characteristic, this paper presents and implement a method for analysis of space manipulator collision base on space manipulator’s collision and interference space, and design a traversal algorithm to access to the space, and makes use of interference collision space to analyze collision of space manipulator. The method is a more efficient method, which can meet the real-time requirements of space manipulator control.Finally, a3D visual simulation platform is established to validate the method that proposed in this paper.