technical innovations
Military wants a few good innovators
Troops, toiling in extreme temperatures day and
night, need a ready supply of goods to perform their
job, and making sure the goods are provided is the
job of the U.S. Army Materiel Command.
”As we like to say, if a soldier shoots it, drives it,
flies it, wears it, or eats it, the Army Materiel
Command provides it,” General Benjamin Griffin,
Commanding General of the U.S. Army Materiel
Command, said during a keynote speech on the
Typical components like the cylinder head, valves, and camshafts
are eliminated in the OPOC engine design for enhanced scalability,
whereby the addition of a self-contained module can increase peak
power and torque.
Outer piston
intake
final day of activities at the SAE 2005 World
Congress in Detroit.
Helping the Army develop and refine manned and
unmanned vehicles are engineers, usually industry professionals with a long military association. “In 1917,
SAE members helped develop a Class B five-ton truck
in 69 days,” Griffin said. In the 21st century, the need
to keep the military in a state of technical readiness is
just as important as it was in the 20th century.
”The automotive engineering community represents a vast resource of knowledge and innovation
that could develop innovative solutions to military
needs,” said Gary Rogers, President and CEO of FEV
Engine Technology and President of FEV Testing
Systems. Rogers was part of a Congress panel discussing the topic of doing business with the military.
A company’s ability to develop robust and reliable technologies remains a valued attribute. But in
the context of an ever-changing global scene, the
ability to innovate quickly is equally important. “Just
one world event could alter [the military’s] planning
cycle dramatically,” said Chuck Heine, President of
Technology Development and Diversified Products
for Dana.
Inner piston
exhaust
Inner piston
intake
Inner connecting rods
Outer connecting rods
Crankshaft
End cover
assembly
Intake
manifold
Left and right crankcase
Exhaust
manifold
Outer piston
exhaust
Intake
manifold
End cover
assembly
Exhaust
manifold
The opposed-piston, opposed-cylinder (OPOC) engine configuration being developed for military ground vehicles by FEV
has all the forces acting on the crankshaft and not on the main bearings of the crankcase.
6 SAE OHE June 2005
technical innovations
FEV Engine Technology President and CEO Gary Rogers (right)
reviews the features of the FEV prototype OPOC engine with
Michigan Governor Jennifer Granholm (left) and U.S. Army General
Benjamin Griffin at the SAE World Congress.
Designed by Advanced Propulsion Technologies, this briefcase-size
5-kW generator has fives times the power density of a conventional
generator. The portable auxiliary power unit is appropriate for
delivering in-vehicle power as well as plug-in exportable power.
Product development speed—especially in terms of military
applications—is more the norm than product “optimization
over a protracted development period,” said Michael Bolon,
Senior Vice President of Engineering Design and Development
for General Dynamics Land Systems.
The military environment presents a steady stream of challenges, including around-the-clock wear and tear on equipment, endless dust, and bad roads or no roads at all. “In the
military, there are environmental and operational conditions
that don’t exist in the commercial vehicle world,” said Bolon.
Consider just how different battlefield movements are in
comparison to typical workday commutes. “Sustainability, mobility, safety, reliability, maintainability. These are the same
words used throughout the industry on the commercial side,
only they are used in a more severe environment [on the military side],” said Raymond Corbin, President of AVL
Powertrain Engineering.
Getting information to the right source can be another challenge, as only a fraction of Army vehicles presently have prognosis/diagnostic capabilities. ”We have it in some aircraft today,
but we don’t have it across the fleet. And we don’t have it to
the extent that we’ll need it for the future,” Griffin said.
While a laptop computer can be used to provide a diagnostic scan of a vehicle, Griffin said the military wants prognostic/
diagnostics as an embedded technology because onboard vehicle prognostic/diagnostic information “will help streamline
logistics operations.”
In many instances, industry-to-military technology carryovers
are possible. But not every solution is a ready-packaged commercially available innovation. “A total commercial-off-theshelf approach may not be sufficient, yet the application of
automotive technology is essential in reaching long-term
goals,” said Rogers. FEV engineers recently developed a concept diesel engine that can use diesel fuel or JP8, a military jet
fuel. The OPOC (opposed-piston, opposed-cylinder) engine
features two-stroke uniflow scavenging and asymmetric port
timing.
Developed under a program sponsored by DARPA and the
Department of Defense, the engine uses an electrically assisted turbocharger supplied by Advanced Propulsion
Technologies. “Each module of this engine is self-contained,”
said Rogers.
The engine combines the features of an opposed-piston,
two-crankshaft diesel aircraft engine and the opposed-cylinder
boxer engine. Military targeted applications for the OPOC engine include unmanned aerial vehicles and unmanned ground
vehicles. Because of fewer components, the engine is likely to
have a lower production cost than a conventional internalcombustion engine.
In its basic configuration, the OPOC engine has a mass of
275 lb (125 kg). Lightweight vehicles positively affect fuel
economy. And that fact hits another military target: better fuel
economy. The Army’s medium- and heavy-duty vehicles register
a single-digit fuel economy average. “Fuel, water, and ammunitions are my three biggest weights,” said Griffin.
With hundreds of companies providing a variety of technologies, the military is constantly searching for efficiency in its
supply chain. But beyond the context of efficiency, the route to
developing reliable, robust, and safety-orientated equipment is
not done in isolation. “We need a lot of help from you,” said
Griffin. “I can replace a piece of equipment. I cannot replace a
soldier.”
Kami Buchholz
8 SAE OHE June 2005
technical innovations
TTControl designs to link
unmanned system with victory
TTTech and its subsidiary TTControl are part of the Red Team
working with Carnegie Mellon University (CMU) on the
build of an autonomous vehicle for the 2005 DARPA Grand
Challenge desert race between Los Angeles and Las Vegas.
Last month, DARPA evaluators arrived in Pittsburgh, PA, to test
whether CMU’s H1ghlander—built on a 1999 Hummer chassis
donated by AM General—had the skills to compete in the
175-mi (282-km) challenge through natural and man-made
obstacles that will be part of a “hostile desert terrain” to include mountains, gullies, and dry lakebeds.
According to CMU, DARPA is in the process of evaluating
118 teams, only 40 of which will advance to the next level
of competition that will begin in September prior to the
October 8 Grand Challenge. At press time, DARPA had not
made public its determination on the H1ghlander’s worthiness.
However, CMU’s plan is to have two pieces of equipment at
the starting line of the race, and “one in the winner’s circle.”
Last year, no one was quite that lucky since none of the vehicles finished the race, although CMU’s Sandstorm robotic
vehicle traveled the farthest and fastest. The winning vehicle
this year will be the one that finishes the designated route—
which will not be revealed until two hours before the race begins—the fastest within 10 hours.
Good communication is an important part of any winning
team, and in the Red Team’s case, TTControl has a lot to say
about it. Autonomous racing is no easy task. It requires several
functions to real-time communication and diagnostics, which is
difficult to meet with conventional distributed architectures. To
help achieve such requirements, TTControl, a supplier of both
event-triggered (CAN) and time-triggered communication systems in the form of its patented Time-Triggered Protocol (TTP),
is providing the team with a time-triggered communication
network that consists of four multi-purpose control units.
DARPA’s 2005 Grand Challenge is a field test through the desert
intended to accelerate research and development of autonomous
ground vehicles. Carnegie Mellon University (CMU) has high hopes
that its H1ghlander, shown during its first attempt at navigating in
heavy snow, will win the competition and the $2 million purse.
The H1ghlander maps
terrain with seven laser
range scanners, one of
which is a Riegl scanner that
is pointed and stabilized
by a three-axis gimbal.
Stereo cameras also ride
aboard the gimbal, which is
protected by a lightweight
carbon fiber dome (shown).
10 SAE OHE June 2005
All TTControl hardware units have
been specifically designed to work
under rough conditions, with
strong vibrations, in a wide range
of temperatures, and under the
influence of humidity and water.
CMU chose TTTech and TTControl
hardware for the integration of
a time-triggered by-wire system
with other components on the
vehicle.
One of many computers in the vehicle, the H1ghlander’s active
suspension computer modifies the fluid level in the struts to keep the
vehicle level and stable.
Three TTC 200 control units will be used to regulate the
parking brake, throttle, and transmission, and one TTP-ByWire-Box will control the H1ghlander’s service brake. In addition to the control units, the integrated software suite TTPTools is being used by the Red Team as the development and
production environment for the design and integration of the
time-triggered by-wire system with other components.
Some of those components include electronics from
Caterpillar to control the speed, regulate tire pressure, govern
steering, and communicate with navigation computers. Cat’s
MorElectric system will generate and distribute power to computers, sensors, and actuators. Ontario-based Applanix, a
wholly owned subsidiary of Trimble, is supplying technology
that will estimate the vehicle’s location by combining inertial,
GPS, and odometry data. Data communication will be based
on TTP, which supports very high data rates and fulfills the requirements of hard, real-time systems. One of the primary benefits of TTP is that system extensions or modifications do not
require a system-wide retesting.
All those components and others, including seven Intel
Pentium M computers and one 64-bit Itanium 2, must work
together to autonomously sense and drive the H1ghlander
around hazards, and to victory. Terrain is mapped with seven
laser range scanners, four stereo cameras, and two radar sensors. Some of these are mounted on a gimbal, which operates
“like an animal’s neck” to stabilize and point the sensors. The
gimbal is a collaborative development with Red Team sponsors
HD Systems, Phillips, and KVH. Google, Boeing, and SAIC
are also among the team’s sponsors.
Jean L. Broge
technical innovations
GM Powertrain updates industrial engines
The gasoline version of GM Powertrain‘s 2006 Vortec 3000
industrial engine will now be offered with factory-installed multiport fuel injection (MPFI), the high-output gaseous fuel version
of the engine will offer increased power and torque, and an engine with a 35-kW genset rating at 1800 rpm will also be available. The engines are designed for a variety of mobile and stationary applications. With low emissions and smooth performance in a compact package, all versions of the four-cycle, fourcylinder Vortec 3000 deliver the power and torque of many larger-displacement six-cylinder engines, according to GM.
Because the MPFI system promotes hotter, more complete
combustion and delivers more precise ignition, idle quality and
operational smoothness of the 3.0-L engine are enhanced. Fuel
injectors are positioned in the intake ports of a new cylinder
head and spray fuel directly on the back of the intake valves,
enhancing power, throttle response, and startup characteristics—a design that promotes more complete combustion and
helps reduce emissions.
An adaptable, returnless-type fuel rail on the Vortec 3000
incorporates a pressure test port, allowing OEMs to customize
the fuel system as needed. An OEM-supplied engine control
module (ECM) constantly measures the engine’s air/fuel ratio
and adjusts it continually to optimize performance and emissions.
Automotive-type Multec II fuel injectors are used for their
compact size and cold-start performance. These injectors are
expected to reduce maintenance costs because they are similar
to the injectors used in hundreds of thousands of GM passenger vehicles.
An upgraded, state-of-the-art ignition system is linked to
the engine’s ECM. A 58X crankshaft position sensing system
provides a highly accurate crankshaft position signal to the
ECM, which helps provide a more stable spark advance. The
crankshaft position sensing system is complemented with a
camshaft position sensor and upgraded high-voltage switch
distributor and coil that enable the engine’s sequential fuel injection. When combined with the OEM’s ECM, this ignition
system improves the reliability of the spark as well as the accuracy of the timing, claims GM. Also, a boss and threaded attachment hole is provided on the engine block for an OEMsupplied knock sensor.
The use of many proven automotive components helped
reduce development time for the Vortec 3000 with MPFI. The
crankshaft sensor is from GM Powertrain’s Ecotec four-cylinder
engine, while the ignition coil is the same as the Vortec 5700
V8 engine. Many of the emissions-related components, such as
the PCV valve and crankcase breather, were also lifted from
automotive applications.
A version of the new, eight-port cast iron cylinder head
used on the Vortec 3000 with MPFI is also used on the new
Vortec 3000 high-output gaseous fuel engine without MPFI.
The new cylinder head design reduces complexity and allows
OEM manufacturers to design and tailor the intake manifold
and exhaust system to fit their needs. Large, high-flow inlet
ports cast into the head enhance the engine’s performance by
increasing the volume and velocity of the air/fuel mixture.
With the MPFI version, the head incorporates the injection
system’s fuel rail and injectors. On the high-output gaseous
12 SAE OHE June 2005
The Vortec 3000 engine for mobile and stationary applications is now
offered with factory-installed multiport fuel injection gasoline and
high-output gaseous versions. The engine has the longest history of
any industrial engine offered by GM Powertrain.
fuel engine, the new cylinder head combines with a higher
10.5:1 compression ratio to take advantage of the high octane
rating of propane and natural gas, resulting in ratings of 65 hp
(48 kW) at 1800 rpm with propane and 60 hp (45 kW) at 1800
rpm with natural gas. The MPFI gasoline version is rated at 99
hp (74 kW) at 3000 rpm.
A unique camshaft profile for the high-output gaseous fuel
engine is designed with lower valve lift and longer duration,
which enhances low-speed torque. Maximum power is sustained at approximately 1800 rpm.
All Vortec 3000 industrial engines feature common traits
including a one-piece rear main seal, high-voltage switch distributor and ignition coil (except engines without MPFI), upgraded coolant pump seals, and long-life platinum-tip spark
plugs. Also, the engines are filled at the factory with GF-4 engine oil, which uses an ash-free antioxidant that prolongs the
life of the emissions control system. It also resists breakdown
caused by high-temperature oxidation. Along with improved
fuel economy, this new oil can extend the interval between oil
changes, according to GM. The engine’s bore and stroke is 4.0
x 3.6 in (101.6 x 91.4 mm).
The new MPFI and high-output gaseous fuel versions were
developed jointly at GM Powertrain’s Toluca, Mexico, engineering and assembly facility and GM Powertrain’s Pontiac, MI, development center. The engines are built at Toluca, Mexico.
Jean L. Broge
technical innovations
Virtual layout of hydraulic hoses
Hydraulic hose routing in agricultural and construction equipment is a time-consuming process that is often done late in the
product-development cycle. Hoses must be routed in and
around other components and must be protected from abrasion and other hazards. Commercial-off-the-shelf software for
generating hose layouts in a CAD environment does not consider physical properties such as weight and hose pressure, or
take into account the axial, torsional, and bending stiffnesses
of the component.
“Hydraulic hoses can measure between 1 and 50 ft long,
and under pressure a 50-ft hose can change in length by almost a foot,” said David Jackson, Senior Engineer at the John
Deere Technical Center—Moline. “More often than not, engineers apply the trial-and-error/cut-to-fit method during the first
prototype build. As a result, 25 to 33% of the initial hose
lengths have to be adjusted as changes are made to the hardware. Last-minute routing of hoses delays the launch of new
products.”
And hose routing problems are not restricted to construction and agricultural vehicles. These problems touch on all
machines and vehicles with pressure hoses for hydraulic,
VR Hose with MSC.ADAMS was used by Deere engineers to analyze
the initial routing of two pressurized hydraulic hoses with an
articulating joint. A potential wear issue was identified where the
hose bends around the D-ring, and another was the close proximity
of hoses to the manifold cover. Since the D-ring keeps the hose from
moving out of position, it could not be completely removed, so the
solution was to reposition and reorient the D-ring.
Checking the length of pressurized hydraulic hoses trapped between
surfaces was also evaluated in the virtual world by Deere engineers.
The hose-to-surface interaction was captured, which allowed
discovery of a potential issue with a tight bend radii in the hose.
14 SAE OHE June 2005
Another tricky problem tackled by Deere engineers in the virtual
world was simulation of a bundle of hoses through an articulating
joint to visualize potential hose interaction and verify correct hose
length.
pneumatic, brake, and other systems. There may not be as
many hoses on an automobile, but with air-conditioning,
brake, and fuel systems, hoses still must be routed to minimize
wear and exposure to extreme temperatures.
VR Hose, a virtual-reality hose-routing tool, was co-developed by Deere and Iowa State University for design and simulation of hoses before prototype build. Deere engineers can
now analyze VR Hose models with MSC.ADAMS software,
from MSC.Software.
Hoses need to be the correct length so they have sufficient
slack, and must be clamped and properly guided so they will
not wear excessively, pinch, or cut. VR Hose allows engineers
to trace routes while viewing or walking around a 3-D model
much like they would a physical prototype with cut-to-fit methods. The virtual reality interface is a series of subroutines developed to run within Jack, an ergonomics and human factors
software package from UGS.
The VR Hose program provides simulation of static hoses,
but many hoses undergo dynamic motion, which requires simulation of the movement and interaction with other hoses,
guides, and hardware surfaces. MSC.ADAMS is used for modeling such machine dynamics as folding, articulating, dumping,
and length extension due to pressure, as if a vehicle were going through its normal operations.
“The ADAMS analysis functionality allows our engineers to
view and better understand the dynamic effects of physical
properties, gravity, pressure, and contact much earlier in the design process,” said Kurt Chipperfield, Virtual Reality Engineer at
John Deere Dubuque Works. “It allows engineers to see how
hardware changes will affect hose routes long before the first
prototype is built and hose specifications are sent to suppliers.”
VR Hose builds an ADAMS mathematical model of the hose
based on the physical properties and route defined by the engineer. By selecting Analysis in VR Hose, a rigid-body model is
created in ADAMS for simulating the dynamic motion of the
surrounding machine hardware. Beam elements are used to
model the flexibility of the hose, with stiffness properties derived from physical test data.
Contacts are defined between hoses, guides, and hardware.
Because the hose is divided into many different beam elements,
one of the greatest challenges is defining the contact relationship between each of the beam elements and the surfaces it can
touch. The current process requires an engineer to design the
hose layout and an analyst to run the simulation. The analyst is
technical innovations
required because the process of setting up the ADAMS model
and defining contacts is complex and time consuming.
Although stress and strain analyses are not run, forces and
velocities are collected. The engineer then can decide if that
hose design will work for the given application or whether it
needs to be lengthened, shortened, or rerouted.
Previously, engineers were unable to see what a hose looked
like when it moved until a physical machine was available. Hoses
that would move through a range of motion on a backhoe
boom or a front-end loader were designed in one position. The
length of the hose and where to clamp it to keep it from pinching, binding, or rubbing and causing excessive wear was a best
guess. Allowing designers to see the dynamic motion of the hoses before first prototype build is an enormous advance.
“We are developing VR Hose at the corporate level for use
throughout the enterprise,” said Jackson. “To date it has been
used in a limited production environment. The objective is to
automate the process of defining the contacts between beam
elements. This will allow VR Hose analysis to be put in the
hands of the engineer to design the hose layout virtually.”
“Eventually, it is expected that the engineer will be able to
push a button, VR Hose will build the dynamic models, and
ADAMS will run a dynamic analysis through a basic range of
motion and indicate where changes, if any, need to be made,”
said Chipperfield.
David Alexander
NAC gets on light-duty hybrid platform
Technology transfer and dual-use were the key phrases during
the unveiling of the MP Hybrid vehicle at the SAE 2005 World
Congress by the National Automotive Center (NAC) group
within the U.S. Army’s Tank Automotive Research,
Development, and Engineering Center.
Development of the prototype light-duty vehicle began by a
handful of engineers only 90 days before the April show in cooperation with Quantum Technologies and California
Motors “to show the Army user various technologies that could
be available on an on-post vehicle,” said Hal Almand, Light
Platform Team Leader at NAC. ”We really like what we see.”
Both Brigadier General William Lenaers, Commanding General of
TACOM Life Cycle Management Command in Warren, MI, and U.S.
Senator Carl Levin of Michigan stressed that the technology transfer
between the military and commercial industry has significantly
impacted the effectiveness of U.S. troops.
The dual-use MP Hybrid unveiled at the SAE World Congress in
April by the National Automotive Center is expected to reduce
overall costs by providing a common base system and maximum
commonality of other non-automotive components required to meet
military needs.
18 SAE OHE June 2005
The NAC has no doubt that the MP Hybrid dual-use platform fills a niche, “enhancing the capabilities of vehicle fleets
by providing a low-cost alternative to the HMMWV for traditionally non-tactical operations,” said Dennis J. Wend,
Executive Director of NAC.
The military variant will feature a removable, opposed-piston 5-kW auxiliary power unit (APU) from Advanced
Propulsion Technologies (APT). The lightweight 5-kW generator is about the size of a briefcase and delivers what is described as “unprecedented power density” for in-vehicle power
needs, plug-in exportable power, and soldier-portable battlefield operations.
APT’s electric power cell plugs into a vehicle’s fuel and electrical system to produce quiet exportable power independent of
the main engine. This arrangement can support both battlefield
operations and commercial vehicle heating and cooling systems.
“The APU offers five times the power density of conventional generators and five times greater specific power, with an
engine that has 40% fewer parts compared with conventional
four-stroke engines,” said Wend.
Overall, the four-wheel-drive military vehicle includes a series hybrid diesel/electric transmission, the 5-kW APU, and two
7.5-kW electric motors. The front and rear drivetrains are completely independent and managed through an onboard vehicle
Military applications are expected to include military police
patrols, base operations, routine personnel transport, and remote power generation and supply. The vehicle will also be
applicable for “agencies engaged in patrol tasks such as counter-terrorism and interdiction operations along U.S. borders,”
said Wend. The civilian variant is expected to be used for campus operations, airport surveillance, and various off-highway
applications.
MP Hybrid has undergone extensive analytical simulation
and will soon undergo real-life tests “in the dirt” at the Army’s
Yuma Proving Ground in Arizona and/or at NAC’s demo site in
Quantico, VA, according to Almand.
Four people with a combined mass up to 900 lb (408 kg)
can be accommodated in the MP Hybrid, with an additional
500-lb (225-kg) payload cargo capacity.
Jean L. Broge
Robin puts big things in little packages
The one-cylinder, four-cycle EH41 industrial engine manufactured
for Robin by Fuji Heavy Industries features a compact design, a
QuickStart starting system combined with a HotSpark electronic
system, and an overhead valve design that provides for improved
power, fuel consumption, and emissions characteristics.
Robin’s durable two-cylinder, four-cycle V-Twin features a bore and
stroke of 84 x 65 mm (3.3 x 2.6 in) and an aluminum alloy block with
a cast iron cylinder liner.
As CONEXPO gets bigger and bigger, Robin Subaru had on
display at the show engines that remain comfortably small. Its
compact EH41 slant-cylinder, four-cycle engine is suitable for a
variety of medium- to heavy-duty construction, agricultural, and
recreational equipment such as air compressors, pumps, and
pressure washers.
The air-cooled EH41 is designed with a splash-type lubrication system and a large-capacity air cleaner with dual elements
that further protect the engine and provide enhanced reliability.
The overhead valve (OHV) design of the EH41 is said to provide for combustion characteristics that contribute to improved
power, fuel consumption, and emissions qualities. The engine
offers a maximum power output of 13.5 hp (10 kW) at 3600
rpm and provides easy, one-pull starts by teaming a QuickStart
starting system and a HotSpark electronic ignition system with
an automatic decompression system, which reduces the recoil
pulling force. It has a bore and stroke of 89 x 65 mm (3.5 x 2.6
in) and a compression ratio of 8.3:1.
According to Robin, a subsidiary of Fuji Heavy Industries,
the design of the EH41 limits vibration due to the use of lighter
reciprocating parts. Additionally, improvements have been made
to lower the combustion and mechanical noises, and the engine
features a low-noise, rust-resistant muffler.
Robin also had on display its V-Twin cylinder series, four-cycle
OHV gasoline engines suitable for a variety of industrial and
construction equipment including tractors, trenchers, and small
construction and agriculture equipment. Although the V-Twins
come in small packages, Robin claims they are high-performance engines that range from 18 to 25 hp (13 to 19 kW) and
provide smooth torque throughout the rpm range and improved
breathing at high rpm. The EH63 offers a power output of 18
hp (13 kW) while the EH64 provides 20 hp (15 kW) and the
EH65 features 22 hp (16 kW). The EH72, the largest of the engines, boasts a power output of 25 hp (19 kW).
Both the EH 41 and V-Twin engines offer enhanced durability
and long life with a host of heavy-duty features including an
aluminum alloy block, cast-iron cylinder liners, forged steel
crankshaft, and high loading capacity ball bearing. The V-Twins
feature a full pressure lubrication system with trochoid-type oil
pump and a large-capacity air cleaner with dual elements
that enhance reliability. The engine’s combustion chamber, combined with a precisely tuned intake and exhaust valve system,
lowers fuel consumption and exhaust emissions in comparison
to conventional side valve engines, says Robin.
Jean L. Broge
June 2005 SAE OHE 19
technical innovations
control system. While the version on the show floor was a solely non-tactical vehicle with a fiberglass composite body, it will
be able to accept a modular Level III ballistic lightweight armor
package designed with advanced composites by Klune
Industries.
“The armor shows really good ballistic integrity,” said
Almand. “About six or seven bolts hook the body, or ‘bathtub,’
onto the chassis. The bathtub portion has a mass of about 700
lb, so four or five people can actually lift it up, put it on, and
bolt it.”
Four-wheel drive is also included on the civilian variant, which
features a parallel hybrid diesel/electric transmission, 7.5-kW
electric motor, 18-hp (13-kW) diesel engine, and onboard ac
outlets. The modular vehicle includes front and rear suspension
and wheel subassemblies similar to the military version, as well
as the use of other similar components where possible.
technical innovations
Real-time hybrid-vehicle simulator
Hybrid vehicles have been gaining in market share in on-highway vehicles, courtesy mainly of Japanese automakers.
However, such systems have been present in off-highway vehicles for a bit longer than in on-highway; thus, one would
guess, a lot of the bugs have been removed courtesy of those
off-highway applications.
To help both industries, Opal-RT Technologies now offers
small but powerful Intel Pentium M-based RT-LAB hybrid-electrical powertrain simulators. These compact, real-time simulators can simulate electronic motor drives, fuel cells, and conventional combustion engines to test electronic control units
(ECUs). The simulator is fully integrated with MATLAB,
Simulink, and Real Time Workshop and can execute several
third-party models in real time.
motor drive controller tester (MDCT) simulates the insulated gate
bipolar transistor (IGBT)—or other power semiconductor switches—switching and harmonics on motor current and voltages
with a sampling frequency of 100 kHz (10 ms sampling time).
The ECU is interfaced with the simulators through fast and
precise I/O systems. The ECU and simulator are then connected
in closed loop such that the ECU reacts as if it would be connected to the real motor drive. This technique, called hardware-in-the-loop testing, is used to test control unit performance under several normal and abnormal operating conditions before connecting the ECU to the real motor drive.
The MDCT can accommodate systems with a pulse-width
modulation carrier frequency up to 10 kHz and can simulate
IGBT firing delays and dead time effects with a resolution as
Motor drive
Command station
Controller
Pentium M modules
Data logging &
auxiliary controllers
Opal-RT Technologies is now offering a range of small Intel Pentium M-based hybrid-electrical powertrain real-time simulators for electronic
motor drives, fuel cells, and conventional combustion engines to test electronic control units.
The Pentium M new instruction set and large cache memory
enables the simulation of power electronic systems to be executed within microseconds to achieve required precision,
claims Opal-RT. For a typical electrical system simulation application, a relatively low-cost 1.6-GHz Pentium M achieves the
same effective performance as the Pentium 4 Xeon 3.2-GHz
processor but consumes less than 20 W, making it more cost
efficient.
“The new mobile processor technologies offered by Intel
and AMD will enable the development of a new generation of
portable dynamic instruments optimized for electronic control
testing,” said Jean Belanger, Chief Technology Officer of OpalRT. “These instruments will combine traditional data logger,
signal generators, and real-time simulators in compact and robust packages.”
Using Opal-RT’s OP5000 series I/O interface and signal-conditioning modules, the system can simulate motor drives. The
20 SAE OHE June 2005
low as 500 ns. Such precision is achieved by using unique simulation techniques including real-time interpolation and FPGA
(field-programmable gate array) I/O boards to capture firing
pulses and generate encoder pulses with 10-ns resolution.
In the RT-LAB hybrid-electrical powertrain simulator, the first
processor simulates the motor drive. The second processor is
used for data logging and for the simulation of models with
slower dynamic. FireWire, SignalWire, or InfiniBand achieves
real-time data communication between Pentium M modules.
Several Pentium M simulators can be interconnected together and with a shared-memory simulation server if needed
to simulate more complex systems for integration testing. Each
compact simulator module can also develop control algorithms
and implement rapid control prototypes for laboratory and invehicle testing.
Jean L. Broge