Research On Modeling And Control Methods Of Production Emergency Changes In Supply Chain System

With the further development of globalization and the increasingly close connection between the various links of the supply chain system,global emergencies such as the Corona Virus Disease 2019(COVID-2019),the Russia-Ukraine conflict,and the Silicon Valley bank collapse have brought unprecedented challenges to the management of the supply chain system.Therefore,it is of great theoretical value and practical significance to the field of supply chain system management for enterprise managers to make reasonable production plans quickly and effectively to guarantee the normal operation of the supply chain system in the face of unexpected events.This paper constructs a supply chain system dynamics model and a supply chain system virtual entity through digital twin technology and uses the supply chain system dynamics model as the base model to carry out research on three different degrees of impact on the supply chain system caused by emergencies and to formulate corresponding production emergency change plans.The specific research contents are as follows:(1)A production contingency compensation change model based on an improved sliding mode control and disturbance observer is constructed for the scenario of demand disturbance in the supply chain system caused by unexpected events.First,an improved sliding mode controller based on adaptive fast variable power convergence law is designed to quickly stabilize the supply chain system inventory converging to the target inventory level.Second,a disturbance observer is designed to track the sudden demand disturbance in real-time,and the production controller is compensated for the change in real-time by feedforward compensation.Finally,the simulation results based on the virtual entities of the supply chain system show that the constructed production contingency compensation change model can quickly weaken the effect of sudden demand disturbances and has good contingency capability.(2)A production contingency switching change model based on multi-model adaptive sliding mode control is proposed for the scenario where a supply chain system is shifted by a single enterprise and demand perturbation is caused by an unexpected event.First,the supply chain system under the contingency is viewed as a multi-model system based on the different degrees of impact on the supply chain system caused by the shift of individual enterprises.Secondly,the adaptive sliding mode control based on RBF neural network is proposed to design corresponding production controllers according to different sub-model systems and design a reasonable switching mechanism to realize the emergency switching change of each production controller.Finally,the simulation results based on the virtual entity of the supply chain system show that the production emergency switching change model can quickly and accurately complete the switching change of production controllers according to different situations,with high switching accuracy and emergency capability.(3)A real-time change model for production contingency based on H_?robust sliding mode control and digital twin is proposed for the scenario where a complex environment with multiple contingencies coexists and causes different impacts on the supply chain system.Firstly,the supply chain system is constructed as an uncertain supply chain system with time-varying parameters and unknown perturbation parameters in the complex environment where multiple contingencies coexist,and the H_?robust sliding mode controller is designed for the uncertain supply chain system to ensure that the inventory quantity of the supply chain system enterprises is stable at the target inventory quantity while suppressing the effect of unknown demand perturbation on the supply chain system;secondly,the digital twin of the supply chain system is used for real-time Secondly,using the characteristics of real-time communication of the digital twin of the supply chain system,the time-varying parameters of the supply chain in the current state are obtained in real time to realize real-time changes to the production plan of the supply chain system.Finally,the simulation experiments based on the digital twin of the supply chain system show that the constructed production emergency real-time change model is feasible and has good emergency response capability.