平面轨迹机构的静态综合可靠性分析

Static Composite Reliability of Planar Path Mechanisms

传统的机构运动可靠性研究多以各分量运动误差来建立机构运动的可靠性分析模型,进而获得各分量误差落在允许误差范围内的概率。为获得各分量误差的综合效应,将机构运动在每一坐标分量上的失效看作一种失效模式,基于多失效模式提出轨迹机构的综合运动可靠性分析模型。在各运动分量的相关性分析的基础上,采用二维正态分布导出各运动分量的联合概率密度,最后采用数值积分方法求解机构运动综合可靠度。通过数值实例对该模型的有效性和精度进行验证,其结果表明,这一模型能够反映机构在整个运动区间上某指定点处整体失效情况。

In traditional probabilistic mechanism analysis, reliability analysis model of path generating mechanisms is set up with motion error of each coordinate. Because these kinds of mechanisms have multiple motion Output components. The probability that a mechanism realizes its desired motion within a specified error is then calculated. In this work, each component of motion is taken as a failure mode and the kinematic reliability analysis model of path generating mechanisms is proposed with multiple failure modes in order to obtain the comprehensive effect of component errors. Based on statistical correlation analysis of failure events, the joint probability density function of each motion error is obtained by using two-dimensional normal distribution. The kinematic reliability is then calcu- lated with the numerical integration method. The method is demonstrated by the analysis of a four-bar path generating mechanism. This model can provide a global failure of probability at a specified point during the motion interval.