函数生成机构的稳健性综合

连杆机构的真实输出和期望输出之间的误差一般由结构误差和机械误差2部分组成，尽管采用确定性的优化方法可以使机构只产生很小的结构误差，但由于各构件尺寸制造误差和各运动副间隙可能会造成显著的机械误差，理论上可行的机构实际上往往是不可行的。为此，将这2种误差综合在一起考虑，建立了机构输出误差的概率模型，提出了函数生成机构的稳健性综合方法。对于给定的置信水平借助于置信系数的概念将概率约束转化为确定性约束，从而机构稳健性综合被构造成确定性非线性优化问题。最后以一个生成函数的铰链四杆机构为例进行了数值计箅。

Robust Synthesis of Function Generating Linkages

The deviation of the actual output from the desired one of a linkage generally consists of structural and mechanical errors. Although using the deterministic optimization techniques it is possible to synthesize a linkage which can produce a very small structural error, tolerances on the link dimensions and clearances in the moving hinges may result in the actual output of the mechanism deviating from the desired one in a significant way. A feasible linkage in theory is usually unfeasible in practice. In this paper, a probabilistic model of the deviation is constructed and a robust optimization procedure for the function generating mechanism taking account of both the structural and mechanical errors is presented. Probabilistic restrictions are converted deterministic ones by means of the concept of the confidence coefficient for given confidence leveis. The robust synthesis procedure of the linkages is formulated as a non-linear determined optimization problem. Finaliy, a four-bar function generating linkage is selected for numerical illustration.