关键词: 机器人示教编程, 复杂曲面, 虚拟夹具, 曲面流形, 操作者意图

Abstract:  In order to solve the difficulties of virtual fixture construction and adaptive adjustment according to the operators intention in robot programming by demonstration for complex surface machining,a Programming by Demonstration (PbD) strategy for virtual fixture generation and iterative updating was proposed. A prior virtual fixture was constructed offline by demonstrating surface manifold. If the prior virtual fixture matched the surfaces to be machined, the spring-damping system was used to online compensate the path deviations of demonstration. Otherwise, the iterative correction was realized by adaptive adjustment of virtual fixture stiffness and flexibility. The results show that the construction of virtual fixture based on surface manifold is simple and has generalization characteristics, which improves the construction efficiency of complex surface virtual fixtures; in the auxiliary demonstrating processes of the virtual fixtures by using the sinusoidal and fan track , the position and orientation errors of auxiliary demonstrated path may be decreased at least by 84% and 81% respectively, and the virtual fixture may be adjusted adaptively according to the operators intention to better match the target surfaces.

Key words:  robot programming by demonstration； complex surface； virtual fixture ； surface manifold, operators intention