Intended Audience and Required Skills and Knowledge
MATLAB
MATLAB is a technical computing software package that integrates programming, calculation, and visualization. MATLAB also includes Simulink; this software package is discussed below. As RT-LAB works in conjunction with these environments to define models, you must be familiar with aspects of MATLAB as related to Simulink.
If you are intending on gathering data from one system and then process the data offline, for example, you must know how to save the data and retrieve it using MATLAB and to display data through the different on-screen tools available within the software.
Simulink
Simulink is a software package that enables modeling, simulation, and analysis of dynamic systems. You describe its models graphically, following a precise format based on a library of blocks. RT-LAB uses Simulink to define models that will be executed by the real-time multiprocessing system and defines its own simulation parameters through Simulink’s.
It is expected that you have a clear understanding of Simulink’s operation, particularly regarding the model definition and the model’s various simulation parameters. If you intend to create your own blocks to interact with RT-LAB, you should know how to create Simulink icons (S-functions) for both the command station and target environments.
Organization of this Guide
There are several guides offered in the list of RT-LAB documentation:
This document is the user guide. The topics covered are:
| Introduction | Provides an introduction to simulation and the principles behind RT-LAB. |
|---|---|
| Getting Started | Presents tutorials on the RT-LAB workbench and RT-LAB simulator. |
| Concepts | Provides a complete description of all concepts of RT-LAB, as views or editors, related to the workbench and the simulator. |
| Tasks | Describes how to realize tasks, as building or executing a model, using the RT-LAB workbench. |
Basic Concepts
This section describes the basics of RT-LAB, provides an overview of the simulation process, from designing and validating the model, to using block diagrams and I/O devices, to running the simulation and using the Console as a graphic interface.
Designing and Validating Models | The starting point for any simulation is a mathematical model of the system components to be simulated. You design and validate a model by analyzing the system to be modeled and implementing the model in the dynamic simulation software. RT-LAB is designed to automate the execution of simulations for models made with offline dynamic simulation software, like Simulink, in a real-time multiprocessing environment. RT-LAB is fully scalable, enabling you to separate mathematical models into blocks to be run in parallel on a cluster of machines, without changing the model’s behavior, introducing real-time glitches, or causing deadlocks. |
|---|---|
Using Block Diagrams | Using block diagrams for programming simplifies the entry of parameters and guarantees complete and exact documentation of the system being modeled. Once the model is validated, you separate it into subsystems and insert appropriate communication blocks. Each subsystem is executed by target nodes in RT-LAB’s distributed system. |
Using I/O Devices | RT-LAB supports the use of Input/Output devices to enable the integration of external physical components into the system. This arrangement is commonly known as a Hardware-in-the-Loop The optimized use of I/O devices enables RT-LAB to work as a programmable control system that presents a flexible real-time user-machine interface. Interfaces for I/O devices are configured through custom blocks that need only be added and connected to the graphics model’s blocks. RT-LAB’s automatic code generator will map the model’s data onto the physical I/O cards. |
Running Simulations | Once the original model is separated into subsystems associated with the various processors, each portion of the model is automatically coded in C and built for execution by the target nodes. Target nodes are commercial PCs, equipped with PC-compatible processors, that operate under a Windows or Linux environment. |
Executing and Manipulating Model Parameters | When the C coding and compilation are complete, RT-LAB automatically distributes its computation among the target nodes and provides an interface so you can execute the simulation and manipulate the model’s parameters. The result is a high-performance simulation that can run in parallel and in real-time. |
Working with RT-LAB
RT-LAB software runs on a hardware configuration consisting of the following components:
- Command station (also called the host)
- Compilation node
- Target nodes (normally including the compilation node)
- I/O boards
RT-LAB software is configured on a Windows or Linux computer called the command station. The Command Station is a PC workstation that serves as your interface.
The Command Station enables you to:
- edit and modify models
- see model data
- run the original model under its simulation software (Simulink)
- distribute code
- control the simulator's Go/Stop sequences
Simulations can be run entirely on the command station computer, but they are typically run on one or more target nodes.
For real-time simulation, the preferred operating system for the target nodes is OPAL-RT Linux (x86- based). When there are multiple target nodes, one of them is designated as the compilation node.
The Command Station and target node(s) communicate with each other using communication links and for hardware-in-the-loop simulations, target nodes may also communicate with other devices through I/O boards.
The target nodes are real-time processing and communication computers that use commercial processors.
These computers can include Dolphin Interconnect for a real-time communication interface, as well as I/O boards for accessing external equipment.
The real-time target nodes perform:
- real-time execution of the model’s simulation;
- real-time communication between the nodes and I/Os;
- initialization of the I/O systems;
- acquisition of the model’s internal variables and external outputs through I/O modules;
- implementation of user-performed online parameters modification;
- recording data on a local hard drive, if desired;
- supervision of the execution of the model’s simulation and communication with other nodes.
The compilation node is used to compile the generated C code. Any target node could be the compilation node.
Various analog, digital, and timer I/O boards are supported by RT-LAB. These enable connection to external equipment for applications such as HIL.