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Popular Mechanics

Crash-Proof UAVs Fly Blind at MIT

Friday, April 25th, 2008

Here’s another great story from our friends at Popular Mechanics that looks at cutting edge research into drones that fly autonomously inside structures. That’s something that until now could only be done (barely) by wheeled mini-bots. But as you can see from this report, engineers still have a long way to go.

It’s not the most attractive spy bot, but the unmanned aerial vehicle hovering some 20 ft. away is doing its job. For now, that means staying right where it is, weaving ever so slightly under the weight of the webcam strapped to its back. There’s nothing particularly interesting to look at with this UAV, a commercial four-rotor model that any RC hobbyist could put together. But no one is piloting this modified drone — it’s flying autonomously, stabilized a few feet above the floor of MIT’s RAVEN lab. Like most of the aircraft tested here, this model is a puppet, receiving input not from onboard processors, but from a nearby computer.

As it continues to buzz in place, an array of 18 motion-capture cameras tracks the UAV, providing 3D positioning data to determine just how stable it is. Specifically, those baleful red cameras — the same kind Hollywood visual effects teams use to transpose an actor’s movements to a computer-generated counterpart — are tracking the tiny Styrofoam balls attached to the drone. On the computer monitor, these balls show up in real time, mapping the UAV as a cluster of dots, swaying in midair. I’m somewhere between impressed and bored when the drone begins to drift. A second later and it slams into a plexiglass divider, as hard as a hockey player.

It will take some time to figure out why this little craft suddenly lost control. But that’s the point of RAVEN, or Real-Time Indoor Autonomous Vehicle Test Environment, where geeks capture every flight — and collision — in painstaking detail. There are no accidents here, just problems that haven’t been sufficiently analyzed. “RAVEN gives us the freedom to test whatever we can build,” says Jonathan How, director of MIT’s Aerospace Controls Lab. “And we can build wonderful things, even in 24 hours.“

One of the researchers has done just that, and is now preparing to fly a drone that was redesigned, then cobbled together out of lightweight foam core. Of course, this isn’t exactly the next generation of missile-packing Predators; the toylike creation in front of me, with its circular wing and miniature nose-mounted propeller, is more of a testbed than a prototype. All of the UAVs covering nearly every surface of this lab, from high-end RC planes the size of a small child to a store-bought flying insect produced by WowWee, are just tools to develop flight control algorithms for indoor robots.

As challenging as it is to make something fly itself, designing a drone that can function indoors is even harder. For an indoor UAV to meet all of the military’s expectations, it would need to be able to fly into a building and find a suitable spot to perch and observe, all without relying on GPS contact. “The ultimate vehicle is a bat that you can download data from,” How says. Bats have the ability to perch, plus echo location to detect obstacles, and the agility to keep from slamming into them.

(more…)

Lessons From the Accidental Nuke Flyby

Wednesday, April 9th, 2008

A great inside look at a Pentagon after-action report on that embarrassing nuke flub where the Air Force flew a couple doomsday weapons across the US without even knowing it.

Let’s hope this report doesn’t just collect dust on some general’s shelf and that the recommendations are actually implemented.

From our friends at Popular Mechanics:

One might think that the United States’ nuclear weapons — the cornerstone deterrent in the country’s arsenal — would be treated with the utmost precision.

This comfortable illusion was shaken on Aug. 31, 2007, when crews loaded six live nuclear warheads onto a B-52 bomber and flew from Minot Air Force Base in North Dakota to Barksdale Air Force Base in Louisiana, cruising over the nation’s heartland. Each warhead was 10 times more powerful than the atomic bombs dropped on Hiroshima and Nagasaki during World War II.

During the analysis of the incident by the Defense Science Board (DSB), released this month, the ugly truth came out: America’s nukes are so neglected that they are stored alongside conventional missiles, with nothing but an 8.5 x 11-in. sheet of paper to differentiate the two. The last day in August, Air Force personnel loaded the nuclear warheads on a routine repositioning of weapons stocks, believing them to be cruise missiles.

The system of checks and balances has degraded to a point that six of the planet’s most powerful weapons were missing for 36 hours — and no one noticed until they had landed in Louisiana. “The process and systemic problems that allowed such an incident have developed over more than a decade and have the potential for much more serious consequences,” the report warns.

So what can be learned by this near miss, and how can something worse be avoided?

1. No one Air Force command is solely responsible for taking care of nuclear weapons.

There are plenty of weapons systems and missions out there, and each one is more exciting and has a higher priority within the command structure.

The DSB report notes that, after the demise of Strategic Air Command, three operational Air Force commands took over the nation’s nuclear weapons: ICBMs went to Air Force Space Command; bombers went to Air Combat Command, and Air Mobility Command retained ownership of the refueling portion of the bomber missions. That means that there is no one central place where the nuclear mission — upkeep, training and such — is the primary mission. So the nukes got lost in the post-Cold War shuffle.

Recommendations in the report include the establishment of an Assistant Secretary of Defense for Nuclear Enterprise to focus solely on nuclear missions. This person would report directly to the Secretary of Defense. The DSB report notes that the U.S. Navy, which handles nuclear missiles in its submarine fleet, has a system that keeps those weapons under one banner, “Strategic Systems Programs.” It’s commanded by a rear admiral, whereas in the Air Force the highest rank with a primary, daily focus on nukes is that of colonel. “While the attack submarines no longer routinely carry nuclear missiles, the submarine forces retain their nuclear legacy and nuclear focus,” the report says.

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NASA Moon Mission in Jeopardy

Thursday, March 13th, 2008

NASA’s current plan for manned space exploration focuses on establishing a base on the moon, as a vital steppingstone for a visit to Mars. The initiative has been trumpeted by the Bush administration, which wants the first mission to launch by 2020. But trouble is brewing as a growing group of former mission managers, planetary scientists and astronauts argues against any manned moon mission at all. One alternative, they say: Send astronauts to an asteroid as a better preparation for a Martian landing.

The dissenters gathered at a meeting of the Planetary Society at Stanford University. “We want to get a positive recommendation to the new administration,” says Planetary Society executive director Louis D. Friedman. He supports an eventual mission to Mars, but argues that the current moon scheme was selected with inadequate debate after a speech by President Bush in January 2004. “If you said humans’ and Mars’ [to NASA officials] in the same sentence, you would receive a figurative slap on the face, and then four months later [the moon-to-Mars plan] was the main point on a viewgraph at the highest levels.”

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Radar Tech Could Shift Military Might

Wednesday, March 12th, 2008

This month Lockheed Martin released a 280-word statement from its radar research headquarters in New Jersey announcing a breakthrough test of an advanced radar platform. And while the tech world shrugged, people watching the evolution of radar saw another step for a system that could have a dramatic effect on future world affairs, from American missile-tracking platforms in the Czech Republic to the ship-based defense of the Taiwan Straits.

The new radar system, called digital beamforming, could become a game-changing technology that may help defeat an overwhelming attack on U.S. warships by missiles. It could also answer one of the chief complaints about ballistic missile defense systems — that decoys or other countermeasures could easily hide a warhead and spoof interceptors. If placed on satellites, new spy and environmental monitoring missions become possible from orbit.

All this comes as an improvement to an existing system called phased-array radar. While traditional radars spin their faces to seek targets, phased-array radars guide a reflective beam electronically from a stationary panel. They can track things by moving the main beam very quickly, within microseconds, at numerous targets. But the phased array systems cannot seamlessly track multiple targets at the same time without losing resolution. Lockheed’s improvement on these radars allows true simultaneous tracking, with each target followed by a dedicated radar beam.

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Protecting Spacecraft from Space-Junk

Monday, March 3rd, 2008

Micrometeorites and undetectable bits of space junk as small as 0.4 mm pose a serious threat to every current and future manned space mission. These dust-size particles travel as fast as 12 miles per second, packing enough momentum to melt aluminum spacecraft skin — or turn it into a puff of vapor.

To find small holes, astronauts must use handheld ultrasonic devices such as directional microphones — a time-consuming process. NASA scientists seeking other solutions are focusing on new wireless technologies that can find tiny leaks by tracking vibrations across a spacecrafts metal skin.

“There is turbulence as the air spreads in the vacuum, and that reacts against the plate at the edge of the hole,” says Dale Chimenti, a professor at Iowa State University who’s developing the inch-long sensors for NASA.

(more…)

Robot Surgeons Closer Than You Think

Friday, December 28th, 2007

robot-doctor.jpg

While aboard a DC-9 aircraft, a remote operator uses a robot to suture a section of simulated tissue.

If a robot surgeon is treating you, your life is in danger. That’s not due to any machine-borne malice, but because current research into autonomous surgery is focused on battlefield casualties barely clinging to life and astronauts injured on distant planets. To demonstrate how that research is progressing, Silicon Valley-based SRI International and the University of Cincinnati held a series of tests this past September that sound like a cross between a PR stunt and a B-movie: human doctors squaring off against a robotic surgeon aboard a nose-diving DC-9 aircraft.

During periods of zero gravity and sustained acceleration of 1.8 g’s, a robot made incisions and applied sutures on simulated tissue, while a human surgeon did the same. The purpose: to measure just how precise a remote-operated robot can be, especially in a turbulent or gravity-free environment. SRI hasn’t released its results, but according to PM Advisory Board member Dr. Ken Kamler, who participated in one of the flight tests, the robot seemed to hold its own?until its compensation software was turned off. “The difference was huge,” Kamler says. “It was virtually impossible [for it] to tie a knot.” But with compensation engaged, the bot performed as well as it did on Earth.

And so the tests’ true purpose was to showcase SRI’s software. “We’re not mimicking a surgeon,” says Tom Low, SRI’s director of medical devices and robotics, “but looking at what a robot can do better.” By focusing on adaptive algorithms, SRI wants to move away from remote telesurgery and closer to autonomy. The company plans to build a system for NASA that could treat an astronaut on Mars, where communication delays of more than 20 minutes would make telesurgery impossible…

Read more about robotic doctors and other high-tech stories from Popular Mechanics at Military​.com.

– Christian