最佳逼近法求解定传动比连杆机构的精度预测

应用误差理论对最佳逼近法求解从动杆作近似等速运动的平面连杆机构的理论运动精度进行了分析，导出了误差传动比公式，利用计算机绘制了误差曲线，从而为仪器仪表中实现线性位移的平面连杆机构的尺度综合提供了精度预测手段和重要的评估参数。

THE ACCURACY CALCULATION FOR LINKAGE MECHANISM WITH CONSTANT TRANSMISSION RATIO BY OPTIMAL APPROXIMATION

The planar linkage mechanism with approximately constant transmission ratio in a certain range is applied extensively to industrial automatic process. However, the design of linear planar linkage mechanisms is difficult except parallelogram mechanism. The functional optimum approximation to solve the geometric parameters of this mechanism is a good method, but the control of its kinematic accuracy always can not be solved completely. This paper combined the classical theory of approximate synthesis of mechanism with modern computer technique, applied the theory of error to analysing the kinematic accuracy for linkage mechanisms with constant transmission ratio by the optimal approximation, derived the mathematical expressions of error transmission ratio, drew error curves by computer, thus furnished the precision predicting method and an important estimative parameter for dimensional synthesis of linkage mechanism realizing approximate linear displacement in instruments.