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, the simulation would take 10 minutes as well.
Real-time simulation occurs commonly in
computer gaming
A personal computer game, also known as a PC game or computer game, is a type of video game played on a personal computer (PC) rather than a video game console or arcade machine. Its defining characteristics include: more diverse and user-det ...
, but also is important in the industrial market for operator training and off-line controller tuning. Computer languages like
LabVIEW
Laboratory Virtual Instrument Engineering Workbench (LabVIEW) is a system-design platform and development environment for a visual programming language from National Instruments.
The graphical language is named "G"; not to be confused with G-c ...
,
VisSim
VisSim is a visual block diagram program for 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 acquire ...
and
Simulink
Simulink is a MATLAB-based graphical programming environment for modeling, simulating and analyzing multidomain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block libraries. It offers t ...
allow quick creation of such real-time simulations and have connections to industrial displays and
programmable logic controller
A programmable logic controller (PLC) or programmable controller is an industrial computer that has been ruggedized and adapted for the control of manufacturing processes, such as assembly lines, machines, robotic devices, or any activity t ...
s via
OLE for
process control
An industrial process control in continuous production processes is a discipline that uses industrial control systems to achieve a production level of consistency, economy and safety which could not be achieved purely by human manual control. ...
or digital and analog
I/O card
In computing, an expansion card (also called an expansion board, adapter card, peripheral card or accessory card) is a printed circuit board that can be inserted into an electrical connector, or expansion slot (also referred to as a bus sl ...
s. Several real-time simulator are available on the market like xPC Target and
RT-LAB for mechatronic systems and using
Simulink
Simulink is a MATLAB-based graphical programming environment for modeling, simulating and analyzing multidomain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block libraries. It offers t ...
,
eFPGASIM and
eDRIVESIM for power electronic simulation and
eMEGASIM,
HYPERSIM and RTDS for power grid real-time (RTS) simulation.
What is real-time simulation
In a real-time simulation the simulation is performed in a
discrete time
In mathematical dynamics, discrete time and continuous time are two alternative frameworks within which variables that evolve over time are modeled.
Discrete time
Discrete time views values of variables as occurring at distinct, separate "po ...
with constant step also known as fixed step simulation as time moves forward in 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.
Real-time simulation in academic curricula
Real-time simulators are used extensively in many engineering fields. As a consequence, the inclusion of simulation applications in academic curricula can provide great value to the student. Statistical
power grid
An electrical grid is an interconnected network for electricity delivery from producers to consumers. Electrical grids vary in size and can cover whole countries or continents. It consists of:Kaplan, S. M. (2009). Smart Grid. Electrical Power ...
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.
OPAL-RT Technologies Technical Paper , Real-Time Simulation Technologies in Education: a Link to Modern Engineering Methods and Practices
/ref>
See also
* Human-in-the-loop
*Simulated Real Time Simulated Real Time is a literary method of creating an event with the help of authentic material accompanied by a commentary framework. By publishing documents (letters, diaries, official reports etc.) on the date on which they were written but a s ...
, a literary method unrelated to the type of computer models described on this page.
References
{{reflist
External links
The What, Where and Why of Real-Time Simulation
HYPERSIM , The Power System Simulator of Tomorrow
From Offline Simulation to Real-Time Testing