关键词: 夹持装置, 接触力优化, 力封闭性, 线性梯度流, 重载锻造操作机

Abstract: The configurations of the gripping mechanisms of heavy-duty forging manipulators with underactuated tongs are studied, and the importance and difficulty of force-closure and optimization of the gripping contact forces are analyzed for heavy-duty gripping mechanisms. After the similarities and differences of force-closure grasp or gripping between the heavy-duty grippers and multi-fingered hands are analyzed, the gripping contact forces distributed between the interface of the tongs and the work-piece are considered as an equivalent resultant force whose contact model is friction point contact. Then based on the equivalence of the nonlinear friction cone constraints and the semi-definiteness of certain symmetric matrices that BUSS presented, the characteristics of the force-closure and the distribution of contact forces of heavy forging grippers are analyzed. Based on the features of heavy-duty gripping mechanisms, where the equivalent position distribution of the resultant contact forces is optimized, the iterative algorithm of linear constrained gradient flows is used to optimize the gripping contact forces and calculate the gripping force. Simulation and experimental results demonstrate the effectiveness of the optimization method.

Key words: Force-closure, Gripping mechanism, Heavy-duty forging manipulator, Linear gradient flows, Optimization of contact forces