基于混合算法的内燃机曲柄连杆机构复合目标选配

MULTI-OBJECTIVE SELECTIVE ASSEMBLY OF INTERNAL-COMBUSTION ENGINE LINKAGE OF CRANK-ROD BASED ON IMPROVED HYBRID GENETIC ALGORITHM

在曲柄连杆机构的选配中,为实现在多种装配要求的条件下,对多对零部件同时进行选配,并使剩余的零部件数量最少的复合目标,以提高曲柄连杆机构各零部件的选配成功率和装配质量,建立了复合目标选配的目标函数,确定了约束条件。针对该组合优化问题的特殊性,对传统的基于遗传算法和模拟退火算法的混合算法进行了改进,提高了在初始种群产生阶段进行定向变异的方法,以提高初始种群的平均适应度;并设计了特定的编码方式、交叉运算和变异运算,建立了曲柄连杆机构的复合目标选配方法。最后对该方法进行了有效性验证。

During the course of selective assembly of internal-combustion engine linkage of crank-rod, in order to achieve multi-objective that includes mating several pairs of parts in respective assembly precision demands at the same time, making the surplus parts minimum and increasing the mate rate and the assembly quality of the parts within the linkage of crank-rod, an objective function of multi-objective selective assembly is built and restriction conditions are defined. Then considering the speciality of this combinatorial optimization problem, the conventional hybrid algorithm based on genetic algorithm and simulated annealing algorithm is improved, and a method, to take a directional mutation when forming the initial population, is presented to boost the average fitness of the initial population, meanwhile, specific coding operation, specific crossover operator and specific mutation operator are designed, thereby a multi-objective selective assembly method of the linkage of crank-rod is built. Finally the validity of such method is proved by a practical example.