中文摘要：

以物流中心设施布局问题为对象，提出了考虑出入口及主通道位置不固定情况下的设施布局问题的多目标优化模型并设计了其改进的遗传算法。首先，以物料搬运成本最小、活动关系密切度最大和面积利用率最大为目标，构建了考虑出入口位置不固定条件下的具有I型主通道的设施布局多目标优化数学模型。然后，设计了一种改进的遗传算法，包括：改进的编码、解码方法，追加了解码修正操作，基于惩罚函数策略的适应度函数等。实例测试表明，本算法的执行效率高而且结果稳定，优化效果好，布局结果紧凑适用。

英文摘要：

This paper proposes a multi-objective optimization model of facility layout problem with the unfixed location of the entrance , exit and the main aisle and designs its improved genetic algorithm for the facility layout problem of logistics centers .First, the mathematical programming model is established with the multi-objective concerning minimizing the material handling costs , maximizing the degree of activity relation and maximizing area utilization requirements with the unfixed position of the entrance , exit and the I-type main aisle .Then an improved genetic algorithm is put forward which includes improved coding and decoding , modification operation , and design on the fitness function in penalty function strategy .Finally, an actual experiment is illustrated to verify the efficient and stable performance of the proposed algorithm .The result has shown that the solution has a satisfactory , stable and compact layout .