直线运动机构轨迹可靠性灵敏度分析

Sensitivity Analysis of the Locus Reliability of Linear Motion Mechanism

为提高考虑不确定性因素影响下的直线运动机构轨迹精度,提出了直线运动机构轨迹可靠性灵敏度分析的解析算法。首先,利用等距曲线构造运动轨迹的界限,考虑机构的构件尺寸公差,提出包含机构结构误差和随机误差的误差分析模型,并采用线性化方法导出机构运动误差的统计特征值的解析表达;其次,采用一次二阶矩方法建立了直线运动机构轨迹可靠性分析模型,并推导了机构轨迹可靠度对随机变量均值和方差的灵敏度分析的解析模型;最后,以Hoeken机构为例作了数值计算。

To improve the locus accuracy of linear motion mechanism with uncertainty factor,the analytical algorithm of locus reliability sensitivity analysis for linear motion mechanism is presented. First,by using the equidistant curve,the boundary of motion locus is constructed,taking account of the component size tolerance,the error analysis model of structure error and random error for the linear motion mechanism is proposed.The analytical equations for the statistical characteristic value of the motion error are derived by using the linearization method. And then the first order and second moment（ FOSM） method is applied to solve the locus reliability of linear motion mechanism,and the analytical model for locus reliability sensitivity analysis of linear motion mechanism is derived. At last,a numerical example of Hoeken mechanism is given.