主动过约束并联机构6PUS+UPU力位混合控制

Force-position hybrid control of active over-constraint parallel manipulator 6PUS+UPU

为了解决主动过约束并联机构驱动协调性问题,提出一种基于动力学的力位混合控制策略。以6PUS+UPU并联机构为研究对象,基于运动学分析的基础,利用虚功原理推导了机构整体动力学模型与单分支动力学模型,进而得到机构期望内力;以机构内力和运动精度为控制目标,在力位混合驱动的基础上提出一种基于动力学的力位混合控制策略;以6PUS+UPU机构样机为对象进行控制实验,并对实验结果进行了分析。实验结果显示,所提力位混合控制策略可以提高对主动过约束并联机构内力的控制精度,改善各分支驱动协调性,并能在一定程度上提高机构运动精度。

To deal with the actuation compatibility of active over-constraint parallel manipulator, a dynamic-based force-position hybrid control strategy was proposed. By taking 6PUS＋UPU parallel manipulator as the research object, the whole manipulator dynamic model and the single limb dynamic model were deduced with the principle of virtual work according to the kinematic analysis, and the expected internal force of manipulator was also obtained. With the dynamic model, one kind of force-position hybrid control strategy based on force-position hybrid actuation was proposed, which took the manipulator＇s motion accuracy and internal force as control target. With the 6 PUS＋ UPU prototype as object, the control experiment was carried out and the experiment result was analyzed. Experi- ment result revealed that the proposed dynamics-based control strategy could improve the control accuracy on the in- ternal force of this active over-constraint parallel manipulator, the compatibility of each branch actuations and the ac- curacy of manipulator＇s movements.