Thin-walled parts are widely used in aerospace industry. To reduce the deformation errors of such thin-walled parts in machining and also to achieve simultaneous machining of both sides, a novel dual-robot machining system is developed in this paper. In this system, the local rigidity of the thin-walled parts can be enhanced via mutual support between two robots on both sides of the parts, thus reducing the deformation error caused by the low rigidity of the parts effectively. Further, a new concept of dual-robot stiffness matching is introduced, and the deformation of thin-walled parts caused by stiffness mismatching between two robots is analyzed and given a close-form solution. On basis of this solution, a dual-robot posture optimization model, which can satisfy the stiffness matching constraint and improve the normal stiffness of two robots, is developed and then is solved efficiently using the proposed easy-execution sequential algorithm based on the directed node graph and Dijkstra searching, thus the deformation errors of thin-walled parts in machining can be ulteriorly controlled effectively. Finally, the computer simulation and experiments are performed and the results demonstrate that the developed dual-robot machining system and the stiffness matching-based deformation control strategy can effectively reduce the deformation of thin-walled parts in machining.

中文翻译：

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基于刚度匹配的薄壁零件双机器人协同加工变形误差控制策略

薄壁零件广泛应用于航空航天工业。为了减少此类薄壁零件加工时的变形误差，并实现双面同步加工，本文开发了一种新型双机器人加工系统。该系统中，通过零件两侧两个机器人的相互支撑，可以增强薄壁零件的局部刚度，从而有效减小零件刚度低引起的变形误差。进一步引入了双机器人刚度匹配的新概念，分析了两个机器人刚度不匹配引起的薄壁零件的变形，并给出了闭式解。在此解决方案的基础上，开发了双机器人姿态优化模型，该模型可以满足刚度匹配约束并提高两个机器人的法向刚度，然后使用所提出的基于有向节点的易于执行的顺序算法进行有效求解图形和Dijkstra搜索，从而可以最终有效地控制薄壁零件加工中的变形误差。最后进行了计算机仿真和实验，结果表明所开发的双机器人加工系统和基于刚度匹配的变形控制策略可以有效减少薄壁零件加工中的变形。