Research On Digital Twin Of Discrete Serial Manufacturing System For Energy Saving Operation

As people pay more and more attention to the ecological environment,energy conservation,emission reduction and low-carbon development have become a global consensus.Many emission reduction policies were issued to undertake environmental responsibility and duty in many countries.As an important part of global energy consumption,the energy consumption and energy efficiency of the manufacturing industry has attracted more and more attention.In order to solve the problem of energy saving in discrete serial manufacturing systems,the digital twin system and the real-time energy saving control method on discrete manufacturing system are studied.Firstly,a digital twin architecture for energy saving of discrete serial manufacturing system is constructed.The discrete serial manufacturing system is described in digital space by three levels of data view,model view and service view.The energy saving operation process of discrete manufacturing system is expounded.The system data collected in the physical space will be transmitted to the digital space in real time for analysis.When meeting the energy saving conditions,energy-saving control instructions will be generated and fed back to the physical space to realize the real-time energy saving control operation.For the digital twin demand of energy saving in discrete serial manufacturing system,the data are divided into two categories of real-time data and non-real-time data.Real-time data mainly includes the state of system elements,system statistics,energy-saving control data.Non-real-time data mainly includes system inherent data and system plan data.Then the way of data collection is expounded.The digital twin model and energy saving decision methodology of the manufacturing system are built and various indicators of the system are visualized in the digital space in real time.Socket interaction technology is adopted to realize the real-time interaction of information between the physical space and the digital space.In order to realize real-time energy saving operation control of discrete serial manufacturing system,an energy saving operation method using Max-plus algebra is proposed.Blockage event,starvation event,failure event and failure recovery event of the mechanical equipment are monitored to drive the energy-saving decision analysis to determine the energy-saving target machine.The Max-plus algebra model of the manufacturing system is established to calculate the energy-saving time window of the target machine,which is the sleep time of it.Then the target machine is converted to sleep state and will be restarted after sleep.An experimental case of a discrete serial manufacturing system is adopted to establish the simulated physical system in the discrete simulation software Plant Simulation and the digital twin system in the MATLAB environment.The digital twin system is built to realize real-time energy saving operation and the real-time monitoring.The efficiency of this method is verified by comparing the energy-saving operation results of no-energy operation scenario,single-machine energy-saving operation scenario and multi-machine energysaving operation scenario.