运动解耦且大工作空间三平移机构拓扑设计

Topological Design and Analysis for Parallel Mechanisms with Motion Decoupling and Larger Workspace

根据基于方位特征(POC)方程的并联机构拓扑设计方法和运动解耦设计原理,提出一个运动解耦性优异的单回路三平移子并联机构;设计一类4个具有正向位置符号化、部分运动解耦性且具有较大工作空间的三平移(3T)并联机构;对这类机构进行拓扑特性分析,得到相同的方位特征集(POC)、自由度(DOF)、耦合度(κ)、运动解耦性等主要拓扑特性;对其中一个机构进行运动学、动力学性能分析。根据基于拓扑特征运动学建模原理,求出其符号化位置正反解,以及速度、加速度曲线;基于推导出的位置逆解公式,分析机构的奇异位形及工作空间;根据基于序单开链的虚功原理,进行其动力学建模与分析,求解出机构的驱动力。

According to the topological design method of parallel mechanism based on position and orientation characteristics(POC) equation and the principle of motion decoupling,a three-translation parallel mechanism(PM) with single loop and full motion decoupling was proposed and analyzed.On the basis of this single-loop PM,a third branch chain was added,and then a class of four three-translation(3T) parallel mechanisms with symbolic forward position solutions and partial motion decoupling as well as large working space was designed.Their topological characteristics were analyzed,and the main topological characteristics such as POC,degree of freedom(DOF),coupling degree(κ) and motion decoupling property were obtained.The kinematics and dynamics performance of one of the PMs were analyzed,including the symbolic forward and inverse position solutions according to the principle of kinematic modeling based on topological characteristics.The velocity and acceleration curves were also obtained.Based on the derived Jacobian matrix,the conditions of mechanism singularity were analyzed.According to the deduced inverse position solution formula,the workspace of the PM was analyzed.According to the virtual work principle based on sequence single-open-chains,the dynamic modeling and analysis were carried out to solve the driving force of the PM.The correctness of the dynamic equation was verified by Matlab numerical calculation and ADAMS simulation.The three-translation PMs can be used in industrial space grasping,machining,three-dimensional error compensation and so on.