关键词: 大射电望远镜, 机构, 解耦, 力密度法, 数据结构, 索网

Abstract: The cable mesh mechanism is a kind of flexible, parallel motion mechanism array. The motion theoretical analysis is important for the complex and coupled movement. The theoretical model of the cable mesh mechanism is setup via undigraph, and expressed in computer via adjacency list. The cable is simplified and regarded as a linear spring-sliding pair. Based on force density method, the balance equations of the active node are built, and extended to the whole cable mesh motion mechanism. The problem how to solve the balance equations is discussed, and the positional relationship between actuator ends and active nodes of the cable mesh mechanism is deduced and expressed in iterative equations. Then a position analysis method is built. By programming, the cable mesh motion mechanism of the 30 m model of the five-hundred-meter aperture spherical telescope (FAST) is modeled, and its motion is simulated. The results are same as that simulated in Adams software. The position analysis method is verified. It can be used in the real-time control arithmetic of the FAST active reflector, and can be used in precise adjustment or control of the reflector shape for other large cable mesh antennas and space deployable reflectors as well.

Key words: Cable mesh, Data structure, Decoupling, Force density method, Large radio telescope, Mechanism