平面四杆机构运动精度可靠性分析与数字仿真

Reliability analysis and simulation for kinematics accuracy of the flat four-bar mechanism

通过引入误差随机变量并应用微小位移的线性迭加原理 ,对平面四杆机构分别在仅有杆长尺寸误差或铰链间隙误差以及两种误差同时存在的 3种情况之下 ,对其输出运动误差进行了分析与综合 ;建立了机构运动精度可靠性分析模型 ;利用计算机数字仿真技术 ,考察了机构中杆长尺寸误差和铰链间隙误差随机变量均值和方差的改变对机构输出运动精度可靠度的影响 ,从中获得了一些有意义的结论 .

By taking the flat four bar mechanism as an analyzing object and according to the principle of linear pile up of small displacement, the reliability of the mechanism output kinematics accuracy is analyzed and calculated in three instances, namely only in the presence of the error of bar length, only in the presence of joint gaps of hinge or in the presence of the both of them. The reliability model of mechanism kinematics accuracy is built by taking the error as stochastic variables. On the basis of the analysis of reliability and by making use of the computer simulation, the influence of the change of the stochastic variables mean value and mean square of bar length and hinge joint gaps error on the mechanism output accuracy is discussed, with some important conclusions obtained.