Design of a mechatronic system for application of hardware-in-the-loop simulation technique

Abstract

Classical approaches, using Simulation analysis technique, use a controller model that can – or not – be coupled with a plant model. Usually, the controller and plant models are connected, in a closed-loop behavior, and this kind of Simulation is called Software-in-the-loop Simulation (SIL). However, recently, some directions are being assumed and some recent works deal with Simulation considering the real controller, instead of the controller model, in the closed loop behavior with the plant model and this kind of approach is called Hardwarein- the-loop simulation (HIL). In order to study and to propose some rules about the simulation of real-time systems considering HIL simulation, at the Automation Laboratory of the Centre for Mechanics and Materials Technologies of the University of Minho, Portugal – a workbench especially devoted to this study is being developed. This workbench considers an environment for Simulation, and the respective programming language, and a real controller that interacts with the simulation environment running on a PC. After looking at the available software tools and modeling languages, Dymola simulation environment and Modelica modeling language were chosen. The main reasons for this choice are associated with the unique multi-domain engineering capabilities of Dymola and Modelica that allow to deal, on the same environment, with many different engineering domains like hydraulics, power train, thermodynamics, air-conditioning, vehicle dynamics, mechanical, electrical, electronic, control, thermal, pneumatic, among others... As real controller, the choice was a Programmable Logic Controller (PLC) from OMRON company, the CPM2A model. This paper presents the first step, of this ongoing work, and is focused, mainly, on studying how to exchange information between a real PLC (used, as controller, on the designed workbench) and Dymola software that will run specific plant models, developed in Modelica language, on a Personal Computer.