Model-Based Co-Simulation Method for PLC Programming: Interaction Design and Optimization

The Industrial Internet of Things (IIoT) is an enabling technology for the evolution of automation industry. The programming of Programmable Logic Controller (PLC) is a core task of industrial automation. To improve the accuracy and efficiency of PLC programming for complex control systems, it is necessary to conduct co-simulation between PLCs and simulation modeling software based on Model-Based Design (MBD). In this paper, a unified model-based co-simulation framework for PLC programming is proposed. This framework provides heterogeneous device communication by integrating OPC UA protocol and hardware-in-the-loop (HIL) verification by code generation and loading. To improve the real-time performance of co-simulation, a data exchange optimization problem is constructed by modeling the offset adjustment of each periodic exchanged data, which considers the nonlinear feature of exchange time with respect to data amount. To solve this problem efficiently, a meta-heuristic algorithm based on an adapted sea-horse optimizer is proposed. A tool based on MATLAB/Simulink is developed to validate the proposed framework and optimization method. The results indicate that the proposed framework is compatible, and the optimization approach significantly improves the efficiency of data exchange.