考虑运动副间隙的平面函数机构概率综合

Probabilistic Synthesis of Planar Function Mechanisms With Joint Clearance

运动副间隙是机构系统中最重要的一类不确定性因素,它对机构的运动精度、可靠性以及动力学性能有着重要影响,为此提出一种概率综合方法对含运动副间隙的机构进行运动学设计。首先应用截尾混合降维法对运动副间隙变量的统计相关性进行处理,以此为基础建立含运动副间隙的机构运动误差的概率模型并导出机构运动精度可靠性分析模型。然后在机构确定性综合模型中引入可靠性约束,并以机构运动失效概率最小为目标函数建立机构不确定性综合的数学模型。最后以平面四杆函数机构为例验证方法的有效性。

Joint clearance is the most important uncertainty in mechanisms design. Clearances in the joints affect tremendously the kinematic precision, kinematic reliability and dynamic performance of mechanisms. In this paper, a probabilistic mechanism synthesis method with joint clearance is proposed for mechanisms kinematic design. At first, the Cut Hybrid Dimension Reduction （Cut-HDR） method is applied to handle the statistical correlation of joint clearance variables and then the equivalent probabilistic model of motion error is presented, the reliability analysis model for mechanisms kinematic precision is derived. The probabilistic synthesis model is also constructed with considering reliability as constraint and the minimal kinematic failure probability as the objective function. Finally the method is verified its effectiveness by the synthesis of a four-bar function generator mechanism with joint clearance.