65m射电望远镜副面调整机构容错策略与工作空间边界识别

Fault Tolerance Strategy and Workspace Boundary Identification of Adjusting Mechanism for 65 Meter Radio Telescope

为使65m射电望远镜的Stewart型调整机构在发生单分支驱动故障时仍能正常工作,利用螺旋理论分析了故障时的机构自由度。根据机构自由度数大于任务自由度数的特点,提出了基于冗余自由度来实现机构容错运动的原理,计算并分析了L波段或S波段指向发生故障后机构的工作空间。提出了不规则工作空间边界的数字识别方法,实现了不规则工作空间边界对机构运动范围的约束。实验结果表明,利用该容错原理可实现单分支驱动故障时副面指向的调整。

In order io realize the proper function of a 65m radio telescope＇s Stewart adjusting mechanism with the condition of single link at failure. At first, the degree of freedom （DOF） of the mechanism under the fault condition was analyzed using the screw theory, and the fault tolerant movement principle based on re dundant DOF was proposed according to the number of the mechanism＇s DOF greater than that of the task needed, and the workspace of the adjusting mechanism was calculated and analyzed when it broke down at L band or S band. Then a method to identify the irregular boundary of the workspace was proposed, and the re straint of the movement scope of the mechanism by the boundary was realized. The experimental results show that the fault tolerant theory proposed herein is suitable for the pointing adjustment of the subreflector with single link at failure.