Research On Green Scheduling Technology Of Ship Assembly Construction Workshop Facing Random Disturbance

The increasing carbon emission worldwide has aggravated the problem of global warming,and green development has attracted increasing attention.The development of China’s shipbuilding industry is facing new challenges and transformation needs,and shipbuilding enterprises are also facing the policy pressure to reduce carbon emissions.As a typical manufacturing industry with high energy consumption and high pollution,there is huge space for the shipbuilding industry to achieve energy saving and emission reduction.Reasonable operation scheduling is an effective way to realize energy savings and emission reduction,which helps enterprises reduce costs and increase efficiency to gain a greater competitive advantage.Hybrid flow shop scheduling problem(HFSP)is an extension of the traditional shop scheduling problem,which can meet the needs of product diversification and customization and is widely used in the shipbuilding process.In this thesis,we study the green scheduling technology of ship group construction for random disturbance in view of the problems of difficult scheduling plan making,weak schedule adjustment ability,waste of resources,and large carbon emission in the traditional ship construction production scheduling process.The main research contents of this thesis are as follows.(1)Modeling of the green scheduling problem in ship assembly construction shop.The hybrid flow shop scheduling problem is a combination of flow shop scheduling problem and parallel machine scheduling problem.The modern shipbuilding mode of assembly construction organizes production according to the flow line mode,which is a typical hybrid flow shop scheduling problem.In this thesis,a multi-objective mathematical planning model(MOGHFSP)was established for the hybrid flow shop green scheduling problem of group construction with the objectives of minimizing the completion time and optimizing the green indexes by considering different states of the machine processing process and combining the time constraints and process constraints in the group construction of ships.(2)Research on green scheduling algorithm for ship assembly and construction shop.A multi-objective hybrid enhanced non-dominated sparrow search algorithm was designed to solve the problem model.Firstly,the real number encoding method and decoding method based on the workpiece process and machine are designed for the problem model.Secondly,fast non-dominated sorting was introduced and the population initialization was performed using chaotic initialization strategy.Then the explorer position update formula was improved and a decreasing number of vigilantes strategy was designed to improve the performance of the algorithm.Finally,the effectiveness of the algorithm was verified by numerical tests of arithmetic cases.(3)Research on green rescheduling strategy for shop random disturbances.Firstly,we classify and quantitatively evaluate the shop floor random disturbances in response to the problem that the scheduling plan cannot be executed smoothly due to the existence of random disturbance events in the actual construction process.Then the general structure of the green dynamic rescheduling strategy for random disturbance events was designed on the basis of the initial scheduling scheme.Finally,the practicality of the green rescheduling strategy was verified by a production disturbance example of a group stand-up welding line.(4)Ship erection and construction workshop scheduling software system development.Based on the research of key technologies such as green scheduling mathematical model,green scheduling algorithm,and green re-scheduling strategy of ship erection and construction workshop,the ship erection and construction scheduling software system and each function module were developed.The user management function,basic information management function,scheduling and rescheduling function and scheduling plan viewing function of the software system was designed to realize the intelligence of ship erection and construction workshop scheduling plan making and adjustment.