一种新型三自由度虚轴坐标测量机机构的误差建模与仿真

Error Modeling and Simulation of a Novel 3-DOF Parallel Mechanism of Virtual Axes Coordinate Measure Machine

设计了一种新型三自由度虚轴坐标测量机机构,给出了其运动学正解模型,依据全微分理论,导出测头位置误差与结构参数误差及3个并联驱动杆长度误差之间的相互关系,从而建立起这种新型并联机构的误差模型;然后利用计算机仿真方法,验证了误差模型的准确性,分析了3个并联驱动杆长度变化以及结构参数误差变化对测头位置误差的影响,为该虚轴坐标测量机机构的加工制造及其误差补偿奠定了理论基础,该并联机构还可用于运动模拟器、并联机床等其它并联运动装备。

First, a novel 3-DOF(degree of freedom) parallel mechanism of Virtual Axes Coordinate Measure Machine is presented,and its kinematic forward solutions are provided. Then, according to the theory of the differential coefficient, the relationship between the measuring end position error and the kinematic parameter errors including the errors of three driving poles is deduced, so the error model is obtained. Finally, veracity of the error model is validated by computer simulation, and the influence of the three driving poles'length change and parameters error change on the measuring end position error is analyzed. The work of the paper will provide a solid theory foundation for the manufacture and error compensation of the parallel mechanism. The mechanism can also be used for other parallel movement machines such as movement simulators and parallel machine tools.