Edge Computing-Based Modular Control System for Industrial Environments

Abstract

This paper presents a modular hardware control system tailored for industrial applications. The system presented is designed with electrical protection, guaranteeing the reliable operation of its modules in the presence of various field noises and external disturbances. The modular architecture comprises a principal module (mP) and dedicated expansion modules (mEXs). The principal module serves as the network administrator and facilitates interaction with production and control processes. The mEXs are equipped with sensors, conditioning circuits, analog-to-digital converters, and digital signal processing capabilities. The mEX’s primary function is to acquire local processing field signals and ensure their reliable transmission to the mP. Two specific mEXs were developed for industrial environments: an electrical signal expansion module (mSE) and the vibration signals expansion module (mSV). The EtherCAT protocol serves as a means of communication between the modules, fostering deterministic and real-time interactions while also simplifying the integration and replacement of modules within the modular architecture. The proposed system incorporates local and distributed processing in which data acquisition, processing, and data analysis are carried out closer to where data are generated. Locally processing the acquired data close to the production in the mEX increases the mP availability and network reliability. For the local processing, feature extraction algorithms were developed on the mEX based on a Fast Fourier Transform (FFT) algorithm and a curve-fitting algorithm that accurately represents a given FFT curve by significantly reducing the amount of data that needs to be transmitted over the mP. The proposed system offers a promising solution to use computational intelligence methodologies and meet the growing need for a modular industrial control system with reliable local data processing to reach a smart industry. The case study of acquiring and processing vibration signals from a real cement ball mill showed a good capacity for processing data and reducing the amount of data.