一种新型四自由度并联机器人机构分析

Design and Analysis of a Novel Four-DOF Parallel Mechanism

针对并联机构的构型综合问题,一直是机构学研究的难点和热点。基于螺旋理论构造了一种新型四自由度解耦并联机构,该机构能够实现空间的三维转动和一维移动,具有完全解耦和完全各向同性特点。首先,运用螺旋理论对该机构进行自由度分析,验证了构型方法的正确性。其次,通过建立机构输入输出运动关系,得到机构的雅可比矩阵,同时对机构进行完全解耦输入输出关系分析和机构工作奇异性分析,讨论了机构的完全各向同性、完全解耦结构特性。最后,运用adams软件对该机构进行了运动仿真分析,证明了理论分析的正确性。这种并联机构的稳定性好、刚性好、控制简单,具有良好的应用前景。

It has been the hot spot and difficulty in the research of the mechanism constantly of the configuration of parallel mechanism. A novel fuUy-decoupled three-rotational and one-translational （3R1T） parallel mechanism was proposed based on the theory of screws with the characteristic of fully-isotropy. First,mobility property of the parallel mechanism is analyzed by using the screw theory which demonstrates the validity of the method. Then the forward and inverse position kinematics model is established and the Jacobian matrix of the parallel mechanism is obtained. In addition,the fully-decoupling input and output relationship of the mechanism and singularities are analyzed according to the gained Jacobian matrix and the fully- isotropic and fully-decoupled structure characteristics of the mechanism are discussed. Finally, ADAMS software is used to simulate the motion of the mechanism,and the correctness of the theoretical analysis is proved. Since the good stability,large stiffiness and easy-control,the mechanism has a good application prospect.