缝纫机挑线机构精度最优综合

为了在满足给定精度条件下,使机构各参数偏差尽可能大,本文提出了采用最优化技术对机构进行精度分析和综合的方法。考虑到机构各参数变化对机构输出运动特性的不同程度的影响,选取影响系数有效值作为权系数,从而建立了精度优化设计的数学模型。通过选取原制定公差作为精度优化设计的初始点,判别出机构原制定公差的合理性。最后,对于要求几个特定位置满足所给定的最大允许输出偏差的缝纫机挑线机构,作为实例进行了精度优化分析和综合。

Optimal Synthesis of Accuracy for Sewing Take-up Mechanism

To make the variations of all parameters in the mechanism as big as possible under a given accuracy,a method is presented in this paper to analyse and synthesize the accurary of the mechanism by means of the optimization technology.In consi- deration of different extents of influence on the output kinematic characteristics of the mechanism resulting from the changes in its various parameters,the valid value of sensitivity coefficient is selected as the weight factor,and thus a mathematical model for the optimal design of accuracy is set up.By way of taking the originally designed tolerance of the mechanism as the starting point for the optimal design of accuracy, the reasonability of the tolerance can be determined.Finally,as an example,the accuracy of a sewing take-up mechanism which satisfies the given maximal permissible output variation at certain specified positions has been optimally analysed and synthesised.