基于正交实验设计的并联机构误差分析

介绍了一种新型含恰约束支链3-SPS/S并联机器人机构,为提高终端平台的定位精度,对该并联机构进行误差分析。首先在运动学逆解基础上,对驱动支链的运动方程进行微分,建立该机构位姿输出误差正解数学模型。并在给定机构误差的条件下,考虑末端执行器在工作过程中位姿输出误差的变化情况。利用正交实验设计的思想均衡排布参数的误差水平,对该机构进行精度分析,并绘制某姿态下的误差分布直方图及许用精度范围内的可靠度。结果表明:利用正交实验法能够快速计算误差值,为并联机构的精度设计和运动学参数的标定建立了理论基础。

Error Analysis of Parallel Manipulator Based on Orthogonal Experimental Design

A new kind of constraint error branched chain of 3-SPS/S parallel mechanism of robot was introduced. In order to im-prove the positioning accuracy of terminal platform, the error of this parallel mechanism was analyzed. Firstly based on the kinematics inverse solution, the differential equations of motion for driving chain were set up, and the mathematical model of positive solutions of output poses error of the institutions was established. And the error in a given institutional conditions, the output pose error changes in the process of terminal to perform the work were considered. By using the idea of orthogonal experimental design to equalize distribution of parametric error level, the accuracy of this mechanism was analyzed, the error distribution histogram in one pose and reliability of al-lowable accuracy range were drawn. The results show that, the error values can be quickly calculated by using orthogonal experimenatal method, which establishes theoretic basis for accuracy design of the parallel mechanism and calibration of kinematics parameters.