Real-time simulation

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Real-time simulation refers to a computer model of a physical system that can execute at the same rate as actual "wall clock" time. In other words, the computer model runs at the same rate as the actual physical system. For example, if a tank takes 10 minutes to fill in the real world, it would take 10 minutes to fill in the simulation as well.

Contents

Real-time simulation occurs commonly in computer gaming, but also is important in the industrial market for operator training and off-line controller tuning. [1] Computer languages like LabVIEW, VisSim and Simulink allow quick creation of such real-time simulations and have connections to industrial displays and programmable logic controllers via OLE for process control or digital and analog I/O cards. Several real-time simulators are available on the market including xPC Target and RT-LAB for mechatronic systems, Simulink for power electronic simulation, and RTDS for power grid simulation.

Definition

In a real-time simulation, the simulation is performed in discrete time with a constant step (also known as fixed step) simulation as time moves forward in an equal duration of time. Other techniques having variable step are used for high frequency transients but are unsuitable for real time simulation. In a real time simulation, the time required to solve the internal state equations and functions representing the system must be less than the fixed step. If calculation time exceeds the time of the fixed step, an over run is said to have occurred and the simulation now lags behind the actual time. In simple words, real-time simulation must produce the internal variables and output within the same length of time as its physical counterpart would.

Configuring models to run in real-time enables one to use hardware-in-the-loop simulation to test controllers. It's possible to make design changes earlier in the development process, reducing costs and shortening the design cycle.

In academic curricula

Real-time simulators are used extensively in many engineering fields. As a result, the inclusion of simulation applications in academic curricula can provide great value to the student. Statistical power grid protection tests, aircraft design and simulation, motor drive controller design methods and space robot integration are a few examples of real-time simulator technology applications. [2]

See also

Related Research Articles

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<span class="mw-page-title-main">Simulation</span> Imitation of the operation of a real-world process or system over time

A simulation is an imitative representation of a process or system that could exist in the real world. In this broad sense, simulation can often be used interchangeably with model. Sometimes a clear distinction between the two terms is made, in which simulations require the use of models; the model represents the key characteristics or behaviors of the selected system or process, whereas the simulation represents the evolution of the model over time. Another way to distinguish between the terms is to define simulation as experimentation with the help of a model. This definition includes time-independent simulations. Often, computers are used to execute the simulation.

<span class="mw-page-title-main">Computer simulation</span> Process of mathematical modelling, performed on a computer

Computer simulation is the process of mathematical modelling, performed on a computer, which is designed to predict the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be determined by comparing their results to the real-world outcomes they aim to predict. Computer simulations have become a useful tool for the mathematical modeling of many natural systems in physics, astrophysics, climatology, chemistry, biology and manufacturing, as well as human systems in economics, psychology, social science, health care and engineering. Simulation of a system is represented as the running of the system's model. It can be used to explore and gain new insights into new technology and to estimate the performance of systems too complex for analytical solutions.

<span class="mw-page-title-main">PLECS</span> Simulation software for electrical circuits

PLECS is a software tool for system-level simulations of electrical circuits developed by Plexim. It is especially designed for power electronics but can be used for any electrical network. PLECS includes the possibility to model controls and different physical domains besides the electrical system.

VisSim is a visual block diagram program for the simulation of dynamical systems and model-based design of embedded systems, with its own visual language. It is developed by Visual Solutions of Westford, Massachusetts. Visual Solutions was acquired by Altair in August 2014 and its products have been rebranded as Altair Embed as a part of Altair's Model Based Development Suite. With Embed, virtual prototypes of dynamic systems can be developed. Models are built by sliding blocks into the work area and wiring them together with the mouse. Embed automatically converts the control diagrams into C-code ready to be downloaded to the target hardware.

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Dynamic simulation is the use of a computer program to model the time-varying behavior of a dynamical system. The systems are typically described by ordinary differential equations or partial differential equations. A simulation run solves the state-equation system to find the behavior of the state variables over a specified period of time. The equation is solved through numerical integration methods to produce the transient behavior of the state variables. Simulation of dynamic systems predicts the values of model-system state variables, as they are determined by the past state values. This relationship is found by creating a model of the system.

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<span class="mw-page-title-main">MapleSim</span>

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CAMeL-View is a software application, which is used for the model based design of mechatronic systems.

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<span class="mw-page-title-main">SimulationX</span> Software application

SimulationX is a CAE software application running on Microsoft Windows for the physical simulation of technical systems. It is developed and sold by ESI Group.

Continuous Simulation refers to simulation approaches where a system is modeled with the help of variables that change continuously according to a set of differential equations.

The Functional Mock-up Interface defines a standardized interface to be used in computer simulations to develop complex cyber-physical systems.

dSPACE GmbH, located in Paderborn, Germany, is one of the world's leading providers of tools for developing electronic control units.

Simcenter Amesim is a commercial simulation software for the modeling and analysis of multi-domain systems. It is part of systems engineering domain and falls into the mechatronic engineering field.

<span class="mw-page-title-main">Automation Master</span> Open source community maintained project

Automation Master is an open source community maintained project. Automation Master was created to assist in the design, implementation and operation of an automated system.

System-level simulation (SLS) is a collection of practical methods used in the field of systems engineering, in order to simulate, with a computer, the global behavior of large cyber-physical systems.

References