Electromobility: New components going for a test run

ScienceDaily (Oct. 17, 2011) — The future belongs to electrical cars -- that's what most experts think. Unfortunately, there are still a lot of problems that have not been solved. This is the reason why researchers at 33 Fraunhofer institutes put their heads together in the Fraunhofer System Research for Electromobility project to move electromobility one big step ahead.

This two-year project was completed on July 30, 2011, and the demonstrator vehicles they came up with were showcased at the final event in Papenburg, Germany, on September 2, 2011, on the ATP test track.

In the future, it will be whisper-quiet on road because in the long run electric cars will replace the internal combustion engine. But there are still some unanswered questions. For instance, how do you store the electricity in cars? Or what power networks do you need? And anyway, how do you pay for charging your battery? Two years ago, researchers from 33 Fraunhofer institutes joined forces to answer these and many other questions while coordinating the various components of electrical cars. The idea behind this partnership is supporting the German car and supply industry to make sure they stay on top in electromobility for a long time to come. This is why this project was funded by the German Federal Ministry of Education and Research with 34.5 million euros from its Economic Policy Program II.

Professor Ulrich Buller is the Senior Vice President for Research at Fraunhofer Gesellshaft. He describes the idea behind system research: "We take care of overarching aspects starting with generating the energy and going all the way down to business models." Professor Holger Hanselka is the director of the Fraunhofer Institute for Structural Durability and System Reliability LBF and the project coordinator. He goes into detail: "We have defined a total of five concentrations: issues of decentralized power generation and power transport to vehicles, energy storage, vehicle engineering and system integration. We're talking about new value-added chains and getting people to accept the idea of electromobility. We added the concentration of 'function, reliability, testing and launch' in 2011."

After the project was over, the institutes involved unveiled their findings on the ATP test track in Papenburg, Germany, on September 2; researchers invited visitors for a test ride in the experimental vehicles. This is where the first and second generation of Fraunhofer's Frecc0 developmental vehicles are ready for testing. Both of these electrical cars are based upon Artega GT, a two-seater sports car. Franz-Josef Wöstmann, division director at the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Bremen, Germany, says: "We installed commercially available components into the Frecc0 1.0 and concentrated on streamlining the way these components interact." This Fraunhofer Institute took on project management for building the Frecc0 demonstrator vehicle.

Frecc0 2.0 contains components recently developed by these scientists. A case in point are wheel hub motors that the researchers from IFAM conceived in teamwork with their colleagues at the Fraunhofer Institute for Integrated Systems and Device Technology IISB, the Fraunhofer Institute for Mechanics of Materials IWM and the Fraunhofer Institute for Structural Durability and System Reliability LBF. Franz-Josef Wöstmann stresses, "We engineered the motor from the onset for the European market and we selected a diameter to make sure it has room in a 15-inch wheel rim. In turn, the engine is adapted to the available construction space. This is why we had to come up with completely new components with maximum power density -- starting with the power electronics through setting up the cooling right down to the design."

Totally new vehicle designs are possible since the researchers moved the entire drive train -- the entire engine including the center tunnel, cardan shaft and transmission -- out of the car and into the wheel hubs or even eliminated them altogether. For instance, the passenger compartment on a vehicle that is about the same size as a VW Passat would be as big as an S-Class Mercedes. Another advantage is the fact that every wheel gets the performance it needs. This means greater safety for each passenger because each individual wheel cannot only be separately braked, but also accelerated. That gives the wheel hub motor torque vectoring, an advancement over today's ESP. Franz-Josef Wöstmann adds that "all components in the wheel hub motor are designed for series production."

Another innovation is the cast coil. Now, Fraunhofer researchers can cast coils with a new technique instead of winding them as previously. This has the benefit that the installation space in the drive motor is used more efficiently. In contrast to the lot fill factor of approximately 55 percent normal today, experts achieve lot fill factors in excess of 90 percent. This permits higher power density and greater efficiency with an equally large coil installation space. Much smaller coils can be used due to the higher lot fill factors, or aluminum can be used with the same dimensions if engine output is supposed to stay the same. Felix Horch from the Fraunhofer Institute for Manufacturing Technology and Advanced Materials explains: "Thanks to this new production technology, we can substantially reduce the installation space, weight and price for coils."

Incidentally, Fraunhofer scientists were not the only ones to use the Frecc0 as a test platform. In the future, automobile manufacturers and suppliers will be able to use Frecc0 together with the Fraunhofer Institute for Manufacturing Technology and Advanced Materials for testing or advancing new components.

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Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Seeing through walls: New radar technology provides real-time video of what’s going on behind solid walls

ScienceDaily (Oct. 18, 2011) — The ability to see through walls is no longer the stuff of science fiction, thanks to new radar technology developed at MIT's Lincoln Laboratory.

Much as humans and other animals see via waves of visible light that bounce off objects and then strike our eyes' retinas, radar "sees" by sending out radio waves that bounce off targets and return to the radar's receivers. But just as light can't pass through solid objects in quantities large enough for the eye to detect, it's hard to build radar that can penetrate walls well enough to show what's happening behind. Now, Lincoln Lab researchers have built a system that can see through walls from some distance away, giving an instantaneous picture of the activity on the other side.

The researchers' device is an unassuming array of antenna arranged into two rows -- eight receiving elements on top, 13 transmitting ones below -- and some computing equipment, all mounted onto a movable cart. But it has powerful implications for military operations, especially "urban combat situations," says Gregory Charvat, technical staff at Lincoln Lab and the leader of the project.

Waves through walls

Walls, by definition, are solid, and that's certainly true of the four- and eight-inch-thick concrete walls on which the researchers tested their system.

At first, their radar functions as any other: Transmitters emit waves of a certain frequency in the direction of the target. But in this case, each time the waves hit the wall, the concrete blocks more than 99 percent of them from passing through. And that's only half the battle: Once the waves bounce off any targets, they must pass back through the wall to reach the radar's receivers -- and again, 99 percent don't make it. By the time it hits the receivers, the signal is reduced to about 0.0025 percent of its original strength.

But according to Charvat, signal loss from the wall is not even the main challenge. "[Signal] amplifiers are cheap," he says. What has been difficult for through-wall radar systems is achieving the speed, resolution and range necessary to be useful in real time. "If you're in a high-risk combat situation, you don't want one image every 20 minutes, and you don't want to have to stand right next to a potentially dangerous building," Charvat says.

The Lincoln Lab team's system may be used at a range of up to 60 feet away from the wall. (Demos were done at 20 feet, which Charvat says is realistic for an urban combat situation.) And, it gives a real-time picture of movement behind the wall in the form of a video at the rate of 10.8 frames per second.

Filtering for frequencies

One consideration for through-wall radar, Charvat says, is what radio wavelength to use. Longer wavelengths are better able to pass through the wall and back, which makes for a stronger signal; however, they also require a correspondingly larger radar apparatus to resolve individual human targets. The researchers settled on S-band waves, which have about the same wavelength as wireless Internet -- that is, fairly short. That means more signal loss -- hence the need for amplifiers -- but the actual radar device can be kept to about eight and a half feet long. "This, we believe, was a sweet spot because we think it would be mounted on a vehicle of some kind," Charvat says.

Even when the signal-strength problem is addressed with amplifiers, the wall -- whether it's concrete, adobe or any other solid substance -- will always show up as the brightest spot by far. To get around this problem, the researchers use an analog crystal filter, which exploits frequency differences between the modulated waves bouncing off the wall and those coming from the target. "So if the wall is 20 feet away, let's say, it shows up as a 20-kilohertz sine wave. If you, behind the wall, are 30 feet away, maybe you'll show up as a 30-kilohertz sine wave," Charvat says. The filter can be set to allow only waves in the range of 30 kilohertz to pass through to the receivers, effectively deleting the wall from the image so that it doesn't overpower the receiver.

"It's a very capable system mainly because of its real-time imaging capability," says Robert Burkholder, a research professor in Ohio State University's Department of Electrical and Computer Engineering who was not involved with this work. "It also gives very good resolution, due to digital processing and advanced algorithms for image processing. It's a little bit large and bulky for someone to take out in the field," he says, but agrees that mounting it on a truck would be appropriate and useful.

Monitoring movement

In a recent demonstration, Charvat and his colleagues, Lincoln Lab assistant staff John Peabody and former Lincoln Lab technical staff Tyler Ralston, showed how the radar was able to image two humans moving behind solid concrete and cinder-block walls, as well as a human swinging a metal pole in free space. The project won best paper at a recent conference, the 2010 Tri-Services Radar Symposium.

Because the processor uses a subtraction method -- comparing each new picture to the last, and seeing what's changed -- the radar can only detect moving targets, not inanimate objects such as furniture. Still, even a human trying to stand still moves slightly, and the system can detect these small movements to display that human's location.

The system digitizes the signals it receives into video. Currently, humans show up as "blobs" that move about the screen in a bird's-eye-view perspective, as if the viewer were standing on the wall and looking down at the scene behind. The researchers are currently working on algorithms that will automatically convert a blob into a clean symbol to make the system more end-user friendly. "To understand the blobs requires a lot of extra training," Charvat says.

With further refinement, the radar could be used domestically by emergency-response teams and others, but the researchers say they developed the technology primarily with military applications in mind. Charvat says, "This is meant for the urban war fighter … those situations where it's very stressful and it'd be great to know what's behind that wall."

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The above story is reprinted from materials provided by Massachusetts Institute of Technology.

Note: ScienceDaily reserves the right to edit materials for content and length. For further information, please contact the source cited above.

Journal Reference:

T S Ralston, G L Charvat, J E Peabody. Real-time through-wall imaging using an ultrawideband multiple-input multiple-output (MIMO) phased array radar system. Phased Array Systems and Technology (ARRAY), 2010 IEEE International Symposium, 12-15 Oct. 2010 DOI: 10.1109/ARRAY.2010.5613314

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Seeing through walls: New radar technology provides real-time video of what’s going on behind solid walls

ScienceDaily (Oct. 18, 2011) — The ability to see through walls is no longer the stuff of science fiction, thanks to new radar technology developed at MIT's Lincoln Laboratory.

Much as humans and other animals see via waves of visible light that bounce off objects and then strike our eyes' retinas, radar "sees" by sending out radio waves that bounce off targets and return to the radar's receivers. But just as light can't pass through solid objects in quantities large enough for the eye to detect, it's hard to build radar that can penetrate walls well enough to show what's happening behind. Now, Lincoln Lab researchers have built a system that can see through walls from some distance away, giving an instantaneous picture of the activity on the other side.

The researchers' device is an unassuming array of antenna arranged into two rows -- eight receiving elements on top, 13 transmitting ones below -- and some computing equipment, all mounted onto a movable cart. But it has powerful implications for military operations, especially "urban combat situations," says Gregory Charvat, technical staff at Lincoln Lab and the leader of the project.

Waves through walls

Walls, by definition, are solid, and that's certainly true of the four- and eight-inch-thick concrete walls on which the researchers tested their system.

At first, their radar functions as any other: Transmitters emit waves of a certain frequency in the direction of the target. But in this case, each time the waves hit the wall, the concrete blocks more than 99 percent of them from passing through. And that's only half the battle: Once the waves bounce off any targets, they must pass back through the wall to reach the radar's receivers -- and again, 99 percent don't make it. By the time it hits the receivers, the signal is reduced to about 0.0025 percent of its original strength.

But according to Charvat, signal loss from the wall is not even the main challenge. "[Signal] amplifiers are cheap," he says. What has been difficult for through-wall radar systems is achieving the speed, resolution and range necessary to be useful in real time. "If you're in a high-risk combat situation, you don't want one image every 20 minutes, and you don't want to have to stand right next to a potentially dangerous building," Charvat says.

The Lincoln Lab team's system may be used at a range of up to 60 feet away from the wall. (Demos were done at 20 feet, which Charvat says is realistic for an urban combat situation.) And, it gives a real-time picture of movement behind the wall in the form of a video at the rate of 10.8 frames per second.

Filtering for frequencies

One consideration for through-wall radar, Charvat says, is what radio wavelength to use. Longer wavelengths are better able to pass through the wall and back, which makes for a stronger signal; however, they also require a correspondingly larger radar apparatus to resolve individual human targets. The researchers settled on S-band waves, which have about the same wavelength as wireless Internet -- that is, fairly short. That means more signal loss -- hence the need for amplifiers -- but the actual radar device can be kept to about eight and a half feet long. "This, we believe, was a sweet spot because we think it would be mounted on a vehicle of some kind," Charvat says.

Even when the signal-strength problem is addressed with amplifiers, the wall -- whether it's concrete, adobe or any other solid substance -- will always show up as the brightest spot by far. To get around this problem, the researchers use an analog crystal filter, which exploits frequency differences between the modulated waves bouncing off the wall and those coming from the target. "So if the wall is 20 feet away, let's say, it shows up as a 20-kilohertz sine wave. If you, behind the wall, are 30 feet away, maybe you'll show up as a 30-kilohertz sine wave," Charvat says. The filter can be set to allow only waves in the range of 30 kilohertz to pass through to the receivers, effectively deleting the wall from the image so that it doesn't overpower the receiver.

"It's a very capable system mainly because of its real-time imaging capability," says Robert Burkholder, a research professor in Ohio State University's Department of Electrical and Computer Engineering who was not involved with this work. "It also gives very good resolution, due to digital processing and advanced algorithms for image processing. It's a little bit large and bulky for someone to take out in the field," he says, but agrees that mounting it on a truck would be appropriate and useful.

Monitoring movement

In a recent demonstration, Charvat and his colleagues, Lincoln Lab assistant staff John Peabody and former Lincoln Lab technical staff Tyler Ralston, showed how the radar was able to image two humans moving behind solid concrete and cinder-block walls, as well as a human swinging a metal pole in free space. The project won best paper at a recent conference, the 2010 Tri-Services Radar Symposium.

Because the processor uses a subtraction method -- comparing each new picture to the last, and seeing what's changed -- the radar can only detect moving targets, not inanimate objects such as furniture. Still, even a human trying to stand still moves slightly, and the system can detect these small movements to display that human's location.

The system digitizes the signals it receives into video. Currently, humans show up as "blobs" that move about the screen in a bird's-eye-view perspective, as if the viewer were standing on the wall and looking down at the scene behind. The researchers are currently working on algorithms that will automatically convert a blob into a clean symbol to make the system more end-user friendly. "To understand the blobs requires a lot of extra training," Charvat says.

With further refinement, the radar could be used domestically by emergency-response teams and others, but the researchers say they developed the technology primarily with military applications in mind. Charvat says, "This is meant for the urban war fighter … those situations where it's very stressful and it'd be great to know what's behind that wall."

Recommend this story on Facebook, Twitter,
and Google +1:

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Story Source:

The above story is reprinted from materials provided by Massachusetts Institute of Technology.

Note: ScienceDaily reserves the right to edit materials for content and length. For further information, please contact the source cited above.

Journal Reference:

T S Ralston, G L Charvat, J E Peabody. Real-time through-wall imaging using an ultrawideband multiple-input multiple-output (MIMO) phased array radar system. Phased Array Systems and Technology (ARRAY), 2010 IEEE International Symposium, 12-15 Oct. 2010 DOI: 10.1109/ARRAY.2010.5613314

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Electromobility: New components going for a test run

ScienceDaily (Oct. 17, 2011) — The future belongs to electrical cars -- that's what most experts think. Unfortunately, there are still a lot of problems that have not been solved. This is the reason why researchers at 33 Fraunhofer institutes put their heads together in the Fraunhofer System Research for Electromobility project to move electromobility one big step ahead.

This two-year project was completed on July 30, 2011, and the demonstrator vehicles they came up with were showcased at the final event in Papenburg, Germany, on September 2, 2011, on the ATP test track.

In the future, it will be whisper-quiet on road because in the long run electric cars will replace the internal combustion engine. But there are still some unanswered questions. For instance, how do you store the electricity in cars? Or what power networks do you need? And anyway, how do you pay for charging your battery? Two years ago, researchers from 33 Fraunhofer institutes joined forces to answer these and many other questions while coordinating the various components of electrical cars. The idea behind this partnership is supporting the German car and supply industry to make sure they stay on top in electromobility for a long time to come. This is why this project was funded by the German Federal Ministry of Education and Research with 34.5 million euros from its Economic Policy Program II.

Professor Ulrich Buller is the Senior Vice President for Research at Fraunhofer Gesellshaft. He describes the idea behind system research: "We take care of overarching aspects starting with generating the energy and going all the way down to business models." Professor Holger Hanselka is the director of the Fraunhofer Institute for Structural Durability and System Reliability LBF and the project coordinator. He goes into detail: "We have defined a total of five concentrations: issues of decentralized power generation and power transport to vehicles, energy storage, vehicle engineering and system integration. We're talking about new value-added chains and getting people to accept the idea of electromobility. We added the concentration of 'function, reliability, testing and launch' in 2011."

After the project was over, the institutes involved unveiled their findings on the ATP test track in Papenburg, Germany, on September 2; researchers invited visitors for a test ride in the experimental vehicles. This is where the first and second generation of Fraunhofer's Frecc0 developmental vehicles are ready for testing. Both of these electrical cars are based upon Artega GT, a two-seater sports car. Franz-Josef Wöstmann, division director at the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Bremen, Germany, says: "We installed commercially available components into the Frecc0 1.0 and concentrated on streamlining the way these components interact." This Fraunhofer Institute took on project management for building the Frecc0 demonstrator vehicle.

Frecc0 2.0 contains components recently developed by these scientists. A case in point are wheel hub motors that the researchers from IFAM conceived in teamwork with their colleagues at the Fraunhofer Institute for Integrated Systems and Device Technology IISB, the Fraunhofer Institute for Mechanics of Materials IWM and the Fraunhofer Institute for Structural Durability and System Reliability LBF. Franz-Josef Wöstmann stresses, "We engineered the motor from the onset for the European market and we selected a diameter to make sure it has room in a 15-inch wheel rim. In turn, the engine is adapted to the available construction space. This is why we had to come up with completely new components with maximum power density -- starting with the power electronics through setting up the cooling right down to the design."

Totally new vehicle designs are possible since the researchers moved the entire drive train -- the entire engine including the center tunnel, cardan shaft and transmission -- out of the car and into the wheel hubs or even eliminated them altogether. For instance, the passenger compartment on a vehicle that is about the same size as a VW Passat would be as big as an S-Class Mercedes. Another advantage is the fact that every wheel gets the performance it needs. This means greater safety for each passenger because each individual wheel cannot only be separately braked, but also accelerated. That gives the wheel hub motor torque vectoring, an advancement over today's ESP. Franz-Josef Wöstmann adds that "all components in the wheel hub motor are designed for series production."

Another innovation is the cast coil. Now, Fraunhofer researchers can cast coils with a new technique instead of winding them as previously. This has the benefit that the installation space in the drive motor is used more efficiently. In contrast to the lot fill factor of approximately 55 percent normal today, experts achieve lot fill factors in excess of 90 percent. This permits higher power density and greater efficiency with an equally large coil installation space. Much smaller coils can be used due to the higher lot fill factors, or aluminum can be used with the same dimensions if engine output is supposed to stay the same. Felix Horch from the Fraunhofer Institute for Manufacturing Technology and Advanced Materials explains: "Thanks to this new production technology, we can substantially reduce the installation space, weight and price for coils."

Incidentally, Fraunhofer scientists were not the only ones to use the Frecc0 as a test platform. In the future, automobile manufacturers and suppliers will be able to use Frecc0 together with the Fraunhofer Institute for Manufacturing Technology and Advanced Materials for testing or advancing new components.

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Story Source:

The above story is reprinted from materials provided by Fraunhofer-Gesellschaft.

Note: ScienceDaily reserves the right to edit materials for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Archive Gallery: Going Deep With Vintage Submersibles

The four-wheeled diving car, the world-famous Bathysphere, the farming sub, and more underwater craft from decades past

While touting space as the next great frontier, we tend to forget that our oceans encompass domains that might as well exist on other planets. Like outer space, the deep sea isn't an easy place to access, but explorers reared on Jules Verne and tales of the giant squid couldn't resist the challenge of mapping Earth's most alien habitat. To that end, innovators like aqua-lung inventor Jacques Cousteau, Swiss physicist Auguste Piccard, and aviation pioneer Edwin Link built submersibles fit for the long and treacherous task. As Piccard once said, "Exploration is the sport of the scientist."

Click to launch the photo gallery.

By definition, submersibles lack the autonomy, power, and size of submarines. Most of the vehicles covered in this gallery couldn't function unless they were tethered to a surface ship. While Edwin Link dreamed of using submersible to facilitate week-long "camp outs" under the sea, these vehicles were barely equipped for comfortable living. But for the purposes of exploration, leisure, and even undersea farming, they were perfect (well, as perfect as technology back then would allow).

Appearance-wise, early submersibles shared more in common with land vehicles than military submarines. Early diving cars were squarish, had four wheels, and lacked windows. One even came with a large crane for harvesting sea sponges. This all changed in 1928 when Otis Barton convinced naturalist William Beebe that a small spherical vessel was best suited for resisting the ocean's crushing pressure. Six years later, Beebe and Barton set a diving record when their Bathysphere descended 3,028 feet, making Beebe the first marine biologist to study deep-sea wildlife in its natural surroundings.

Naturally, the Bathysphere's renown drove Beebe's peers to emulate his success. Auguste Piccard, who had previously set an altitude record while ballooning, developed an interest in adapting balloon technology for undersea vehicles. The result? A spherical cabin suspended from an enormous buoyancy device containing 10,000 gallons of aviation gasoline. Piccard's work reaped an incredible reward just two decades later, when his son Jacques Piccard and Lt. Don Walsh became the first (and so far, only) men to reach Challenger Deep, the deepest known point in the world's oceans.

Click through our gallery to read about the Bathysphere, the "U-Drive U-Boat," and other submersibles from decades past.

View the original article here