基于极限约束力螺旋系极少运动副高刚度五轴混联机器人设计理论研究

Five-axis hybrid robots combine the advantages of serial/parallel robots in terms of the work space, stiffness, accuracy, and so on, so they have obvious advantages in the machining of complex structural parts in aerospace and other fields. However, the parallel mechanisms (PMs), based on which the hybrid robots are designed, exist problems of containing many passive joints and unreasonable allocation of the constraint wrenches provided by each branch, so it is difficult to improve the structural stiffness of the hybrid robots. Therefore, this project puts forward the concept of the ultimate constraint wrenches, which reduce the number of mechanism kinematic joints to a minimum. And establishes a set of theoretical system for the type synthesis of PMs with extremely few kinematic joints based on the ultimate constraint wrenches, which can enrich the theory of PMs based on the reciprocal screw theory. It also proposes and defines the indexes of bending and torsion stiffness for the PMs, and considering the structural constraints, builds up a simple criterion for evaluating the stiffness of the PMs, which can provide a new way to evaluate the stiffness performance of PMs at the stage of mechanism design. It studies the principle of degree-of-freedom distribution for the five-axis hybrid robots based on the PMs with extremely few kinematic joints, analyzes the techniques of static and dynamic error compensation, and investigates the algorithm of scale optimization considering multi-indexes, then establishes the design theory of the five-axis hybrid robots taking the high structural stiffness as the objective. It can provide an important theoretical basis and technical support for the development of the hybrid robots with independent intellectual property rights and high precision required by aerospace and other high-end fields, boosting domestic machining equipments to reach high-end.

五轴混联机器人融合了串/并联机器人在工作空间、刚度和精度等方面的优点，在航空航天等领域复杂结构件加工方面优势明显，但是其赖以设计的并联机构存在被动运动副多与各支链约束配置不合理的问题，限制了混联机器人高结构刚度的设计。故本项目提出使并联机构运动副数最少的极限约束力螺旋系概念，建立一套基于极限约束力螺旋系的极少运动副并联机构型综合理论体系，丰富基于约束螺旋的并联机构学理论；提出并定义并联机构抗弯与抗扭刚度指标，建立考虑结构约束的并联机构刚度简便评价标准，为在构型设计阶段并联机构刚度性能的评价提供新途径；研究基于极少运动副并联机构五轴混联机器人的自由度分配原理，研究静态与动态误差补偿技术，研究考虑多性能指标的尺度优化算法，建立以高结构刚度为目标的五轴混联机器人设计理论，为研发具有自主知识产权且满足航空航天等高端制造领域高精度要求的混联机器人提供重要理论基础与技术支撑，助推国产加工装备高端化。

五轴混联机器人融合了串/并联机器人在工作空间、刚度和精度等方面的优点，在航空航天等领域复杂结构件加工方面优势明显，但是其赖以设计的两转一移并联机构存在运动副数目多与各支链约束配置不够合理的问题，限制了以此类机构为基础的混联机器人高刚度设计，而且缺少在构型设计阶段评价并联机构刚度性能优劣的简便标准。故本项目提出使并联机构运动副数最少的极限约束力螺旋系概念，开展极少运动副高刚度五轴混联机器人设计理论研究：研究基于极限约束力螺旋系的极少运动副两转一移并联机构型综合方法；研究考虑结构约束的并联机构刚度简便评价标准；研究基于极少运动副并联机构五轴混联机器人的自由度分配原理；研究基于静态误差补偿的混联机器人运动学标定算法；研究考虑多性能指标的尺度优化算法，建立以高结构刚度为目标的五轴混联机器人设计理论。通过上述研究，本项目建立了一套基于极限约束力螺旋系的极少运动副并联机构型综合理论体系，综合到一系列运动副数目极少的两转一移并联机构，丰富了基于约束螺旋的并联机构学理论；建立了考虑结构约束的并联机构抗弯与抗扭刚度简便评价标准，为并联机构刚度性能评价提供了一条新途径；揭示了五轴混联机器人机构的设计原理，设计出极少运动副高刚度五轴混联机器人；研制出了极少运动副高刚度五轴混联机器人样机，实验表明其具有较高的刚度与定位精度，为研发具有自主知识产权且满足航空航天等高端制造领域高精度要求的混联机器人提供重要理论与技术支撑。本项目共发表高水平学术论文10篇，其中SCI收录4篇，授权发明专利9项（包括国际专利2项），获中国精品科技期刊顶尖学术论文领跑者5000 1篇，学术会议最佳论文提名奖1项。