Abstract:

The COVID-19 pandemic led us to new problems overall, including teaching subjects that typically need practical approaches. For instance, the social distancing situation forced us to investigate new teaching control methods and develop tools to help students learn topics related to the engineering curriculum. This work presents the integration of open-source tools for understanding the basic concepts of industrial automation like system modeling, parameters identification, and system controlling for undergraduate students at UFAM in Manaus- Brazil, in 2020.

The idea was to develop a framework with popular simulators and engage students in developing a particular task. The basic tools utilized were Factory IO, SoMachine, and Node-RED. Factory IO is a 3D industrial process simulator for automation teaching, designed to be user-friendly, that allows the emulation of a Programmable Logic Controller (PLC) and its communication with one simulated industrial plant (its sensors and actuators). SoMachine is an open-source graphic programmer tool that supports ladder programming language powered by Schneider Electric that allows communication with their PLC. With the simulated plant correctly configured, SoMachine is used to perform ladder programming for process automation. In this sense, the sensors and actuators of the simulated process in Factory IO communicate with SoMachine through the virtual PLC through the TCP/IP protocol. SoMachine operates as a server, and FactoryIO serves as a client machine. The sensor signals are sent from the Factory IO.

In contrast, the control signals go the other way around, and SoMachine is responsible for directing the message sent to its destination. Node-RED is an open-source development tool based on block graphical programming developed by IBM that uses a web browser based on JavaScript functions. In our approach, Node-RED has two fundamental roles. The first is constructing a graphical interface, allowing the user to interact with the simulated plant in Factory IO. The second is implementing the control routines that will enable users to interact with the desired controllable variable.

The industrial plant used in our classes to teach control and automation was a typical process tank. The hardware set-up was used in face-to-face experiments before the pandemic situation. It consists of an input valve and an output valve to allow liquid circulation in a plastic container. In addition, there is a level sensor and a flow sensor for monitoring the variables of interest, and the goal is to keep the liquid level inside the tank in a pre-set value. To make the classes as close as possible as the in-person ones, we modeled the complete tank system, sensors, and actuators on the virtual PLC.

This paper wants to show how we recreated this industrial process using Factory IO, SOMachine, and Node-RED to perform process control, allowing the students to monitor the proposed process based on the classic task of controlling the level of a tank. We believe that our choices may help other engineering educators develop their distance laboratory classes efficiently.

Keywords:

Remote engineering laboratories, Industrial automation learning, Simulators in laboratory courses.