Study On The Robustness Of Complex Production Process Under Disturbing Environment

Manufacturing industry is developing towards large-scale manufacturing and super large scale manufacturing.As the base of production,the workshop is a production network associated with many elements,not only carrying a lot of production tasks,but also the intersection of many production data.A production workshop is not only a system of periodic,constant or quasi periodic,but also in another unstable state,namely,chaos.A chaotic system like a workshop is a very sensitive system to the initial value,even in the process of workshop operation,there are slight changes in production conditions such as delivery time change,process route change,machine failure and so on.But as the production process is advancing,these information will also be transferred,accumulated and enlarged,which will further affect other manufacturing units in the manufacturing system.Eventually,it may lead to a long delay in completion time,a sharp increase in production cost or a decline in production stability.Therefore,this paper mainly focuses on the circulation and propagation of disturbance factors in the workshop,the influence on the manufacturing unit,the influence of the system,and the optimization of the scheduling of the workshop.Firstly,we analyze the fluctuating production environment,divide the uncertain factors into two categories and describe their characteristics.The network of polymorphic production system is constructed,and the polymorphism of production system under disturbance environment is described from the perspective of complex network.We further analyze the evolution and polymorphism of production system in the process of disturbance propagation,and the description of the state and network parameters of the manufacturing cell in the process of disturbance propagation.Secondly,combined with the dynamic propagation behavior and production constraints in the network,a robustness evaluation model based on improved coupled map lattice is proposed.Extract the adjacency matrix,intensity and other characteristic parameters,establish linkage effect propagation algorithm.Taking a farm machinery enterprise as an example,the linkage effect of production network under disturbance environment is simulated and analyzed,and an example is given to verify it.The results preliminarily reveal the linkage rule of production system under disturbance environment and the influence of node characteristic parameters on chain propagation.Then the robustness of the complex production process is evaluated.Finally,according to the scheduling problem of job shop in the disturbed environment,based on TOC theory and DBR method,the nodes that influence the robustness of the system are considered as the key nodes.A heuristic scheduling rule based on control key nodes is proposed and verified by simulation analysis.The simulation results show that the proposed algorithm can effectively reduce the total completion time and improve the utilization of manufacturing cells.