The Equipment-location-routing Optimization Of Amphibious Ship Maritime Joint Delivery For Landing Operation

Landing operation is the main form of operation to safeguard national maritime rights and interests and solve disputes.It usually involves the transportation of a large number of equipment,materials and personnel.If there is no reasonable delivery plan,it will seriously affect the operational efficiency and be difficult to achieve the expected operational effect.The beach landing equipment is the core equipment of landing operations,which undertakes the important task of transferring our combatants and equipment from sea to land.In practice,due to the limited number of equipment at the landing site,it is often necessary to mobilize a large number of landing ships from other areas.However,amphibious landing ships are often only suitable for short-distance landing charges,and they are not suitable for long-distance sea navigation,so it is often necessary to use semi-submersible ship and other equipment to transport amphibious landing ships.Under this realistic background,how to select the appropriate amphibious landing ships in the coastal naval bases,and choose the appropriate staging area as the loading position,and then design a reasonable semi-submersible ship transportation route to transport them to the forward staging area,it has become one of the key concerns of our military joint delivery command department.In response to this practical need,this thesis has carried out the following work:(1)This thesis analyzes the operation mechanism and characteristics of the maritime joint delivery system under the background of landing operations,and constructs an equipment-location-routing optimization model with amphibious ship selection,rendezvous selection,semi-submersible ship voyage and route planning as decision variables and the shortest delivery time as the goal.(2)Based on the characteristics of the model and the advantages of different algorithms,this thesis designs a two-layer genetic algorithm combining binary and real numbers to solve the problem.Among them,the upper chromosome solved the selection of amphibious ship and the location of rendezvous,while the lower chromosome planned the route and voyage of semi-submersible ship according to the information transmitted in the upper chromosome,and the upper and lower layer interactive operation completes the optimization.(3)In order to verify the validity of the model and algorithm in this thesis,the calculation example of joint delivery of amphibious ships in the South China Sea was solved,and compared with the single-layer genetic algorithm for three groups of different scale examples to test the performance of the algorithm.The results show that the time required to complete the joint delivery of all amphibious landing ships is 21.9 days.The comparison with the single-layer genetic algorithm shows that:In terms of algorithm accuracy,the double-layer genetic algorithm is better than the single-layer genetic algorithm,which is better than 15%,6% and 6% respectively in the three groups of examples;in the stability of the algorithm,the double-layer genetic algorithm is also better than the single-layer genetic algorithm,which is better than 22%,28% and 5%respectively;in terms of calculation time,single-layer genetic algorithm is better than double-layer genetic algorithm,which is better than 37%,35% and 40% respectively.The above results show that the model and algorithm proposed in this study consider the selection of amphibious landing equipment on the basis of location-routing problem,and can further realize the configuration optimization of amphibious ships in landing operation.The relevant results can provide reference for the logistics command decision-making of our army’s landing operation,so it has obvious practical significance.