Research On Production Line Planning And Operation Scheduling Of Flexible Workshop Considering Low Carbon Emissions

With the proposal of the "two-carbon" target and the acceleration of the greening process in the manufacturing industry,enterprises are faced with the challenges of energy saving and carbon reduction.The energy consumption caused by unreasonable workshop equipment layout and logistics solutions,and the waste of resources caused by unreasonable production scheduling plans,will lead to high production costs and carbon emissions,which not only make the production environment seriously polluted,but also damage the image and economic interests of enterprises.This study takes a "multi-modal" flexible workshop(multiple production modes co-exist and the level of automation varies greatly)as the object of study,and carries out integrated planning of the layout of facilities and equipment and logistics solutions at the macro level,optimises production scheduling at the operational level,and develops a production management monitoring system to realise carbon reduction and real-time monitoring of the operation in all aspects.The system is designed to reduce carbon and costs and to monitor operations in real time.This study focuses on the following aspects:Firstly,based on the modular design concept,a reconfigurable hierarchical facility and equipment spatial layout and logistics integration planning method is proposed.The method takes into account the process flow and process processing time,and uses the K-means algorithm to divide closely related processes into spatially concentrated workgroups,the spatial layout of each workgroup can be flexibly adjusted according to actual needs to adapt to different production modes and process changes.After planning and designing the internal facility layout and logistics scheme of the working group based on human factor engineering,the overall layout optimization model of the working group is established with logistics handling cost,non-logistics relationship and carbon emissions of logistics handling as targets.In order to solve the problem that traditional genetic algorithm is easy to fall into "precocious",a catastrophic genetic algorithm model is designed.The case validation shows that,compared with SLP method,this method can not only obtain the integrated optimization scheme of the layout of facilities and equipment in the working group and the logistics scheme,but also reduce the logistics handling cost by 13.04%and the carbon emissions of logistics equipment by 9.96%after solving by the improved algorithm.Secondly,in view of the situation that processing time often fluctuates due to different operating proficiency of personnel,the uncertain robust optimization theory is adopted to construct a multi-objective uncertain robust optimization job scheduling model with the lowest carbon emission,the minimum total processing cost and the shortest completion time.In order to solve the defects of the traditional NSGA-Ⅱ algorithm,such as insufficient population diversity and low search efficiency,The improved NSGA-Ⅱ algorithm was designed to solve the model.The case validation shows that,compared with the traditional NSGA-Ⅱalgorithm,the improved NSGA-Ⅱ algorithm performs better in terms of inverse generation distance and super volume metric,with a maximum reduction of 7.62%in carbon emission,6.86%in total cost and 7.54%in completion time.The uncertainty sensitivity analysis shows that all three objective functions show a linear increase with increasing uncertainty in processing time.The impact analysis of carbon policies shows that carbon emissions from production are lowest under carbon cap policies,followed by carbon trading policies and highest under carbon tax policies.The results of the above analysis provide a basis for decision making by enterprises and carbon policy makers.Finally,combined with the robust job scheduling optimization method of flexible shop proposed in this study,a set of integrated production scheduling and monitoring management information system suitable for flexible shop is designed,including system management,production job scheduling,production resource management,production data monitoring and visualization,etc.The front-end web page is developed with HTML,CSS,Javascript and other languages under VS code development tool.The research in this study provides solutions to problems of "multi-mode"flexible workshop in the stage of facility planning and job scheduling,such as serious waste of resources,excessive carbon emissions,low production efficiency and so on,and provides a basis for facility layout planning,production job scheduling optimization and carbon decision-making.