中文摘要：

重力货架自动存取系统的双提取操作排序问题等价于在一组提取货物中进行两两配对以生成最小执行成本的双提取操作序列,因此双提取操作排序问题被建模为一个匹配问题.提出一个基于匈牙利方法的启发式方法 RSHM来生成具有最小总行驶时间的双提取命令.为了保证生成可行的双提取操作序列,对称标记法被引入RSHM;为了打破对称标记法引起的无限循环,RSHM被设计成一个递归过程.仿真实验对双负载装卸设备的成本效益和RSHM的性能进行了评价和分析.仿真实验结果显示：与单负载设备相比,采用双负载装卸设备可以节省超过40%的提取操作总行驶时间;与贪婪规则相比,RSHM能够减少5%~10%的总行驶时间.

英文摘要：

The dual-retrieval （DR） operation sequencing problem in the flow-rack automated storage and retrieval system （AS/RS） is modeled as an assignment problem since it is equivalent to pairing outgoing unit-loads for each DR operation. A recursion symmetry Hungarian method （RSHM）, modified from the Hungarian method, is proposed for generating a DR operation sequence with minimal total travel time, in which symmetry marking is introduced to ensure a feasible solution and recursion is adopted to break the endless loop caused by the symmetry marking. Simulation experiments are conducted to evaluate the cost effectiveness and the performance of the proposed method. Experimental results illustrate that compared to the single-shuttle machine, the dual-shuttle machine can reduce more than 40% of the total travel time of retrieval operations, and the RSHM saves about 5% to 10% of the total travel time of retrieval operations compared to the greedy-based heuristic.