减速器的优化设计是一个多变量、多约束、多目标和非线性问题。它的设计变量既有连续型的，也有离散型的，以往对其进行研究，大多把离散变量简化成连续变量处理［１］。这种做法是事先假定离散最优解在连续最优解的附近。但是许多实际问题表明，这种假定并非总成立［２］。减 The optimal design of reducer is a multivariable, multi-constrained, multi-objective and nonlinear problem. Its design variables are both continuous and discrete. In the past, most of them were designed to simplify discrete variables into continuous variables [1]. This approach is based on the assumption that the discrete optimal solution is in the vicinity of the continuous optimal solution. However, many practical problems show that this assumption is not always established [2]. Less