Synchronizing the Virtual and the Real. Testing has become the bottleneck
for CAE, says Doug Marinaro, vice president, Software and Consulting,
at MTS Systems Corp. (Minneapolis, MN). One big reason for this: Testing
data is not in a form that can be readily absorbed by CAE. According to
Marinaro, current attempts to calibrate CAE simulations with physical test data
are low-resolution, expensive and narrowly applied. Consequently,
calibration is time-consuming and requires advanced engineers to do the joband
they may have their own approaches to the task. The need for a tool that is
both quick and standard is apparent.
MTS borrows the Jungian term synchronicity to describe its approach
to bringing the real and virtual test worlds together and has four principles
behind it:
- Correlation continuous calibration between CAE andphysical data
- Access ubiquitous datamanagement
- Speed test process automation
- Communication seamless communication between CAE and physical data
The synchronicity architecture consists of a software layer that connects both
the pre- and post-testing calculation processes of the physical and virtual
procedures, then calibrates them so the results have a direct correlation. MTS
has two new products that use this architecture to achieve specific goals.
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Safedesign
Insight allows CAE simulations to be overlaid on crash test video so
that the differences between the simulated and real worlds can be immediately
recognized.
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Safedesign Insight. A CAE postprocessor for Madymo, Dyna and Nastran
that allows engineers to overlay CAE simulations over high-speed video of physical
crash tests so variances can be seen immediately (current software only allows
for side-by-side comparisons). Test set-ups are visually validated prior to
running to ensure that testing time is not wasted because key adjustments were
neglected. It also automatically correlates between CAE models and actual test
results, and is designed for use with barrier, sled and component tests.
Safepass 201. This toolset is directed at helping companies achieve
FMVSS 201 certification by automating the calculation of impact points and displaying
both the test and CAE results on the vehicle geometry for design validation.
Joe Strelow, MTSs Safety and Engineering Software product manager, says
that over 30 impact points have to be analyzed at least 20 times per vehicle
program, and this can take 8 hours per point using current methods. He says
Safepass 201s automatic calculation function can do the impact point calculations
in less than 30 minutes (reducing total time per analysis to about 4 hours,
including model preparation), and that the tool will automatically adjust for
design changes.
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Leica
Geosystems' new T-Probe: any resemblance to a Klingon dagger is
coincidental.
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Wireless Probe. Leica Geosystems (Norcross, GA) has a new armless and wireless
portable T-Probe for its LTD700/LTD800 laser trackers. The probe can maintain
a 0.1-mm length accuracy over the full length of a car and allows deep parts and
tools to be measured with six degrees of freedom.
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Horiba's
on-board emissions measurement system provides real-time data while the
test vehicle is on the move.
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Emissions Tester in Your Trunk. Horibas OBS-1000 on-board emissions measurement
system fits in the trunk of a test vehicle, which is handy when testing has
to include the effects of traffic and environmental conditions on exhaust emissions.
The system can continuously measure CO, CO2, HC, and NOx and calculate the weight
of exhaust gas generated and fuel consumed per unit of distance. A built-in
GPS receiver and a network of sensors track vehicle position, velocity and engine
revolution data which is fed into a laptop PC with data logging software. The
system can be used to test vehicles using alternative fuels like LPG and CNG
as well as with gasoline- and diesel-powered vehicles.
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South
Florida in a box: the Humilab offers enough space to do humidity calibration
on several instruments while being compact enough to be portable. |
Humidity on Demand. GE General Eastern Instruments, Inc.s (Wilmington,
MA) Humilab is designed for calibrating humidity sensors, transmitters and instruments.
It employs a chilled mirror of polished rhodium as the primary humidity instrument
and infrared optics to control thermoelectric cooling and heating. It uses a
time-proportioned divided flow technique to attain a 0.2% RH relative humidity
stability. The stainless steel chamber has a 644 in.3 volumeenough space
for several instruments to be calibrated simultaneously.
Simulating Software. Lets say you are a controls engineer tasked with
writing the software code that will control an active suspension system. You
want to try out several different algorithms to see which one will give the
suspension the best performance, but when you ask the mechanical engineer who
is designing the suspension components to run your code through his FEA program,
he politely asks you to come back, say, next Tuesday. You need a program that
can tell you the constraints on the suspensions movement without giving
you unnecessary data like material failure limits. Which is where SimMechanics
comes in, as it allows engineers who primarily deal with designing software
to quickly simulate mechanical systems so they can run tests and modify their
control algorithms before ever having to induce a mechanical engineer to run
a full system simulation.
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The
MathWorks' Model-Based Calibration Toolbox lets engineers develop code
for engine management system by displaying easy-to-read graphical representations
of simulated trade-offs.
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Scott Lehman, automotive marketing manager at The MathWorks Inc. (Natick, MA),
producer of SimMechanics, says that the product is part of a move to give engineers
tools with different levels of fidelity more suited to specific needs, and that
dont require advanced software degrees to operate. Five years ago
the people who were doing virtual testing were in research labs and today it
is becoming the mainstream way for production programs to develop things,
he says. That change has come about largely because tools have become more user-friendly.
Lehman explains, In the past, simulations were done in Fortran or C, so
to do it you had to become a software engineer in addition to, say, a controls
engineer. Now it is done in a graphical way. The benefits to development
programs are clear. Not only does the controls engineer not have to wait until
next Tuesday to run his simulation, but when he eventually goes to the mechanical
engineer he can give him high quality algorithms that should help speed the
program along.
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| The
H2000 uses a highly sensitive hydrogen detector to locate leaks smaller
than a bacterium.
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Along the same lines, The MathWorks Model-Based Calibration Toolbox allows
engineers tasked with developing engine management algorithms to run simulations
that refine trade-offs until the desired performance is reached. The big advantage
to using this toolbox is that the engine to be simulated only needs to be run
once on a dynamometer for characterization. The rest of the work can be done
at the desktop, which saves a lot of expensive dyno time. Lehman says that he
expects the demand for the toolbox to grow significantly as automakers develop
more complex hybrid powertrains and struggle to meet ever stricter emissions
standards.
Hydrogen Leak Detector. The H2000 from Sensitor Technologies (Billerica, MA)
uses hydrogen as a tracer gas (in a 5% hydrogen, 95% nitrogen mixture) to detect
leaks. The compact unit is entirely electronic, so there are no pumps, valves
or vacuums to maintain. It can identify leaks independent of temperature and
has a dynamic background compensation function that reduces background interference.