目的 当存储系统出入口位于货架底端中点位置并采取双命令周期存储模式时，对系统尺寸进行设计，以使仓储的空间得到最大化利用。方法 建立三维紧致化存储系统双命令周期行程时间数学模型，假设系统出入口位于货架底端的位置，分6种情形展开讨论，研究自动化仓储系统出入口位置的设计问题。结果 通过模型优化求解，确定选择类型5（使a*=1.1，b*=0.63），系统的长高宽比例为1.1∶0.71∶1.2时，堆垛机运行效率最高。结论 通过仿真得出，当三维紧致化存储系统中货架尺寸长高宽比例为1.1∶0.71∶1.2时，双命令周期下的系统期望行程时间最小，即三维紧致化存储系统在该比例下执行双命令存取操作，耗时最短。

The work aims to design the system dimensions to maximize the storage space, when the input/output ports of the system are at the midpoint of the bottom of the rack. The mathematical model of the dual-command cycle travel time of the 3D compact system was established. It was assumed that the input/output ports of the system were at the bottom of the rack, and the discussion was carried out in six situations to study the design problem of the input/output ports of the automatic storage system. Based on the solution optimized by the model, type 5 was selected (a*=1.1, b*=0.63). When the ratio of length to width to height of the system was 1.1∶0.71∶1.2, the running efficiency of the stacker was the best. From the simulation, when the rack dimensions of the 3D compact system (length:width:height ratio) is 1.1∶0.71∶1.2, the expected travel time of the system under the dual-command cycle is the least, namely the 3D compact system performs the dual-command cycles operation at this ratio for the shortest time.