改进的差分进化算法及在聚丙烯牌号切换优化中的应用

针对差分进化算法早熟问题，提出一种改进差分进化算法，采用动态缩放因子解决优化过程中的变量约束问题，在进化过程中自动地调整控制参数取值以保证变量约束条件；引入聚集度作为参数评估种群分布的密集程度，增加一种新的变异算子在进化过程中根据聚集度情况对部分个体进行后续变异操作，适时调整种群分布，提高种群多样性，增强全局搜索能力。建立了聚丙烯牌号切换优化模型并将改进的差分进化算法应用于牌号切换优化模型的求解，仿真实验结果表明改进的差分进化算法在全局搜索能力和搜索效率两个方面有较大提高。

A modified differential evolution algorithm and its application to optimal grade transition in polypropylene

A modified differential evolution algorithm with dynamic scaling factor and adaptive mutation operator was proposed in this paper. Dynamic scaling factor which was determined according to population information during the evolutionary process, was introduced for handling the constraint optimization problem; adaptive mutation operator which mutate partial individuals based on population diversity was adapted to overcome premature evolution and enhance the probability of finding global optimum. Polypropylene grade transition optimization model was established and the modified differential evolution algorithm was applied to solve the problem. Experiment results demonstrated that both search ability and efficient were superior to those of the original differential evolution algorithm.