A new lightweight high-speed stacker is designed and developed.Its technical parameters are leading the industry level,which can meet the current requirements for high efficiency of intelligent logistics system.Starti...A new lightweight high-speed stacker is designed and developed.Its technical parameters are leading the industry level,which can meet the current requirements for high efficiency of intelligent logistics system.Starting from the key structure of stacker,through the theoretical analysis of the new mechanism and the comparison of the new and old equipment,the advantages of the new mechanism in improving the efficiency and lightweight design of stacker are explained.Through ANSYS Workbench finite element software,the structural strength of the main bearing mechanism is analyzed,and the results show that the strength meets the requirements.展开更多
We study a variety of multi-vehicle generalizations of the Stacker Crane Problem(SCP).The input consists of a mixed graph G=(V,E,A)with vertex set V,edge set E and arc set A,and a nonnegative integer cost function c o...We study a variety of multi-vehicle generalizations of the Stacker Crane Problem(SCP).The input consists of a mixed graph G=(V,E,A)with vertex set V,edge set E and arc set A,and a nonnegative integer cost function c on E∪A.We consider the following three problems:(1)k-depot SCP(k-DSCP).There is a depot set D⊆V containing k distinct depots.The goal is to determine a collection of k closed walks including all the arcs of A such that the total cost of the closed walks is minimized,where each closed walk corresponds to the route of one vehicle and has to start from a distinct depot and return to it.(2)k-SCP.There are no given depots,and each vehicle may start from any vertex and then go back to it.The objective is to find a collection of k closed walks including all the arcs of A such that the total cost of the closed walks is minimized.(3)k-depot Stacker Crane Path Problem(k-DSCPP).There is a depot set D⊆V containing k distinct depots.The aim is to find k(open)walks including all the arcs of A such that the total cost of the walks is minimized,where each(open)walk has to start from a distinct depot but may end at any vertex.We present the first constant-factor approximation algorithms for all the above three problems.To be specific,we give 3-approximation algorithms for the k-DSCP,the k-SCP and the k-DSCPP.If the costs of the arcs are symmetric,i.e.,for every arc there is a parallel edge of no greater cost,we develop better algorithms with approximation ratios max{9/5,2−1/2k+1},2,2,respectively.All the proposed algorithms have a time complexity of O(|V|3)except that the two 2-approximation algorithms run in O(|V|2log|V|)time.展开更多
针对堆垛机研发周期长且其工作过程中信息采集率和工作效率低等问题,提出了基于数字孪生的堆垛机模型可视化设计方法。结合数字孪生技术,基于数字孪生五维模型,利用进程控制对象连接(OLE for Process Control,OPC)统一架构技术搭建堆垛...针对堆垛机研发周期长且其工作过程中信息采集率和工作效率低等问题,提出了基于数字孪生的堆垛机模型可视化设计方法。结合数字孪生技术,基于数字孪生五维模型,利用进程控制对象连接(OLE for Process Control,OPC)统一架构技术搭建堆垛机模型的虚拟调试平台,实现了堆垛机物理模型与数字模型的实时通信和数据交互。通过对堆垛机物理模型工作状态的数据采集,实现了堆垛机工作状态的可视化监测和工作效率的优化,验证了基于数字孪生的堆垛机模型可视化设计方法的可行性。可为堆垛机的研发设计和透明化作业提供参考。展开更多
文摘A new lightweight high-speed stacker is designed and developed.Its technical parameters are leading the industry level,which can meet the current requirements for high efficiency of intelligent logistics system.Starting from the key structure of stacker,through the theoretical analysis of the new mechanism and the comparison of the new and old equipment,the advantages of the new mechanism in improving the efficiency and lightweight design of stacker are explained.Through ANSYS Workbench finite element software,the structural strength of the main bearing mechanism is analyzed,and the results show that the strength meets the requirements.
基金This research was supported by the National Natural Science Foundation of China(Nos.11671135 and 11871213)the Natural Science Foundation of Shanghai(No.19ZR1411800)。
文摘We study a variety of multi-vehicle generalizations of the Stacker Crane Problem(SCP).The input consists of a mixed graph G=(V,E,A)with vertex set V,edge set E and arc set A,and a nonnegative integer cost function c on E∪A.We consider the following three problems:(1)k-depot SCP(k-DSCP).There is a depot set D⊆V containing k distinct depots.The goal is to determine a collection of k closed walks including all the arcs of A such that the total cost of the closed walks is minimized,where each closed walk corresponds to the route of one vehicle and has to start from a distinct depot and return to it.(2)k-SCP.There are no given depots,and each vehicle may start from any vertex and then go back to it.The objective is to find a collection of k closed walks including all the arcs of A such that the total cost of the closed walks is minimized.(3)k-depot Stacker Crane Path Problem(k-DSCPP).There is a depot set D⊆V containing k distinct depots.The aim is to find k(open)walks including all the arcs of A such that the total cost of the walks is minimized,where each(open)walk has to start from a distinct depot but may end at any vertex.We present the first constant-factor approximation algorithms for all the above three problems.To be specific,we give 3-approximation algorithms for the k-DSCP,the k-SCP and the k-DSCPP.If the costs of the arcs are symmetric,i.e.,for every arc there is a parallel edge of no greater cost,we develop better algorithms with approximation ratios max{9/5,2−1/2k+1},2,2,respectively.All the proposed algorithms have a time complexity of O(|V|3)except that the two 2-approximation algorithms run in O(|V|2log|V|)time.
文摘针对堆垛机研发周期长且其工作过程中信息采集率和工作效率低等问题,提出了基于数字孪生的堆垛机模型可视化设计方法。结合数字孪生技术,基于数字孪生五维模型,利用进程控制对象连接(OLE for Process Control,OPC)统一架构技术搭建堆垛机模型的虚拟调试平台,实现了堆垛机物理模型与数字模型的实时通信和数据交互。通过对堆垛机物理模型工作状态的数据采集,实现了堆垛机工作状态的可视化监测和工作效率的优化,验证了基于数字孪生的堆垛机模型可视化设计方法的可行性。可为堆垛机的研发设计和透明化作业提供参考。
