Home Made Drone Beams Wi-Fi
A. R. Drone/Parrot
Unmanned aerial vehicles or UAVs are becoming more and more common. They're commonly by the military to spy in insurgents and more recently, they're being used by law enforcement to investigate criminal behavior in the United States. But it doesn't take a soldier or a police officer to own and operate a UAV. And research labs around the world are advancing the technology, developing a new, diverse generation of UAVs designed to perch on walls, bust drug dealers, fly into storms, look for nuclear disaster survivors and even be controlled with smartphones. Demanding duties mean these vehicles need to be able to fly nonstop for hours, days, and longer. Forget refueling. UAV development is pushing the limits of solar and hydrogen power. It’s also pushing the Federal Aviation Administration to open airspace to smaller unmanned vehicles. “The fact that they’re finally coming up with small unmanned aircraft system regulations that look reasonable, that’s going to take the lid off an industry that’s been waiting for this to happen for years,” says Kevin Kochersberger, director of the Unmanned Systems Lab at Virginia Tech. He gives these ten UAVs high marks for technological prowess, risk and potential for spin-offs:
Perching UAVs Earlier this year, Stanford University researchers created a model-plane sized unmanned aerial vehicle that can fly directly to a wall and then land vertically on it, superhero style. Miniature spines on its feet allow the vehicle to cling to a surface. The feet, with help from the propeller, can be manipulated so the UAV walks the wall to get a better view. “I am impressed with the engineering on the aircraft and the iterations they went through to get that configuration,” Kochersberger says. “It’s going to lead to new technologies.” He says the UAV has the potential to sense data that would otherwise be unobtainable. According to the Stanford team, the weather-resistant vehicle consumes very little power and can quietly monitor an area for days. No bat signal required. In the same vein, a team at MIT designed a control system that allows a foam glider with a single motor on its tail to land on a perch.
Reaper The U.S. Army’s MQ-9 Reaper isn’t exactly new but, along with the Predator drone, it has come a long way in flying continuous missions. The Reaper is a specialty airplane designed for surveillance and equipped with highly accurate laser-guided AGM-114 Hellfire missiles, infrared cameras, and electro-optical cameras on stabilized gimbals. It certainly isn’t cheap -- a four-vehicle Reaper system with sensors costs a cool $53.5 million -- but the advantage is that one can be operated entirely from the ground for customs and border protection. “They’re flying 24 hours a day. If you look at the cost of a manned aircraft flying that many hours, it’s cost effective to keep them up,” Kochersberger says. “When you look at the manpower and the risks that are there to the operator, you’re not putting a pilot at risk.”
Modified RMAX Chopper Kochersberger leads a team at Virginia Tech that transformed a 200-pound Yamaha RMAX helicopter so that it could potentially be sent out after a disaster to search for survivors and gather data on the extent of the damage. The federally funded project took Yamaha’s low-cost, remote-controlled crop dusting chopper and equipped it with autopilot and a special box containing a computer, payload radio, and customized circuit boards. “Our helicopter is the only RMAX that’s flying any missions these days,” Kochersberger says. “Two people can easily handle it and set it up. In this case, it’s to get it up after a nuclear disaster and learn about the nature of the accident, and gather data without putting people in harm’s way in a radioactive environment.” He adds that the team is working on a tethered robot.
Fire Scout The U.S. Navy’s pilotless robocopter, Fire Scout, had an adventurous test flight in the spring. Aviation Week reported that while the Fire Scout was completing surveillance sea trials from the USS McInerney, its operators spotted a speedboat suspected of drug smuggling. The Northrop Grumman vehicle is 31 feet long, ten feet tall, and has a 600-pound lift capacity. Fire Scout’s remote operators wrapped up the test flights and decided to go after the speedboat. The chopper watched the boat for three hours and when it linked up with a fishing boat, law enforcement stepped in and seized about 60 kilos of cocaine. In August, however, Navy operators lost control of the robocopter in restricted airspace above Washington, DC. Ultimately they regained control and landed it safely. The Navy blamed the incident on a software anomaly, and resumed unmanned flights in September. Usually human error is the issue, Kochersberger says. “The majority of the accidents are human ground control operator based.”
Zephyr In July, British defense company QinetiQ’s solar-powered Zephyr broke the world record for flying nonstop without refueling. The thin 110-pound carbon fiber UAV stayed airborne for two weeks straight in Arizona. This version is about 50 percent larger than QinetiQ’s original version, and more aerodynamic. Kochersberger gives the Zephyr high marks. “QinetiQ has been at this for years,” he says. “It stores enough during the day to fly all night.” Paper-thin solar arrays cover the wings, providing power to the lithium-sulfur batteries that kept it aloft in the darkness. The defense company expects its record-breaking UAV will be ideal for conducting environmental research, providing remote communications, and monitoring areas during a natural disaster.
University of Colorado and University of Nebr
Tempest When everyone else is running for cover from a violent storm, the Tempest unmanned aerial vehicle is going straight into it. The UAV and its instruments are part of a large-scale scientific research project called VORTEX2 that aims to understand tornadoes. The 10-foot-wide, 20-pound can move at 100 miles per hour, and has sensors to measure air pressure, moisture, wind speed, and temperature. Initially, researchers from the University of Colorado and the University of Nebraska who developed the Tempest were unsure that their UAV would be able to make measurements in a supercell storm, the kind that spews heavy rain, hail, wind, and sometimes a tornado. Yet last May, when the team got the green light from the FAA, they flew the Tempest into a supercell thunderstorm over northwestern Kansas. The UAV flew for 44 minutes, successfully transmitting meteorological data, along with its position and status, wirelessly to a control station and tracker vehicle on the ground. Kochersberger, who has seen the Tempest up close, says it’s a novel use for a UAV. “I’ve talked to their researchers. I like their design philosophy,” he says. “They certainly got closer to bad weather.”
Phantom Eye In July, Boeing unveiled a prototype for its hydrogen-fueled UAV, Phantom Eye. Designed to fly at 65,000 feet for up to four days straight, the vehicle has two 2.3-liter, four-cylinder engines, can carry 450 pounds of payload, and is scheduled to have its maiden flight in early 2011. Kochersberger compares the Phantom Eye with DARPA’s Vulture program to create a five-year battery-powered UAV that can carry more than 1,000 pounds. While Vulture is more ambitious, he says there’s probably a two- or three-year development cycle before it flies. The Phantom Eye is still on the ground, too, but closer to flying. An airplane that will stay up for several days in orbit as a communications hub is novel, Kochersberger says. “It’s a radical design.”
Automatic Supervisory Adaptive Control When several million dollars’ worth of technology is airborne, it also better be able to keep going after getting shot. The aviation technology company Rockwell Collins designed a flight control system that figures out what goes wrong when an airplane sustains catastrophic damage. The automatic system readjusts instantly to safely land the plane. The system was successfully flight tested in 2008 on an unmanned FA-18 subscale model air vehicle sponsored by DARPA. In Aberdeen, Maryland, the test blew more than 60 percent of the plane’s wing off. The system automatically righted the plane, allowing it to land normally. Last summer, Aviation Week reported that the company has a contract to put its system in an operational UAV. Rockwell Collins’ automatic supervisory adaptive control is based on the known flight control laws that govern the aircraft’s characteristics, Kochersberger says. “They developed a nonlinear flight control algorithm. It will sense the aerodynamics and fly in spite of those inefficiencies,” he says. “It’s really fast, too. If the wing comes off, it’s immediately stable again.” The technology has the potential to keep military personnel and civilian passengers safe.
Solar Eagle DARPA’s Solar Eagle unmanned aerial vehicle is like a low-altitude satellite, Kochersberger says. The solar-powered UAV has loftier goals than the company’s hydrogen-powered Phantom Eye. Currently the Solar Eagle is being designed to have a 400-foot span between wings, carry 1,000 pounds of sensors and payloads, and remain at 65,000 feet for five years. Yes, years. The $89 million project aims to begin flight-testing in two years. Kochersberger expects that the Solar Eagle will spin off new tech related to communications. “Temporary wide area communications that are similar to satellites -- that’s a new industry that would spring up from the use of the airplane,” he says.
A. R. Drone Parrot When one thinks of UAVs, a toy isn’t the first thing that comes to mind. But that’s exactly what the A.R. Drone by French company Parrot is. The half-pound quadricopter is now on the market and costs around $300. Its Wi-Fi system works with Apple’s platforms so the small chopper can be controlled using an iPhone, iPod Touch, or an iPad, and multiple players on a network can compete against one another with the vehicles. Other smart devices should work with the toy in the future, according to the company. Kochersberger credits associate professor Mary Cummings for creating a similar vehicle in her Humans and Automation Lab at MIT. She and her students designed a one-pound quad-rotor UAV that has sensors and a built-in camera, and can be controlled using an iPhone. “The Parrot toy, you could say it’s a game,” Kochersberger says. “But you could put a radio repeater in there to drive it behind the building and relay radio messages.”
Conway, a product manager at Aerohive, which provides corporate IT networks, used a quadrotor frame, some plywood, and an old router from work to built a drone that can provide a Wi-Fi connection over the local LTE phone network. It can even link up to a corporate virtual private network for extra security.
He got the idea two years ago when the open source autopiloting program Adrupilot appeared. Conway had always been interested in robots, as it was his major in college. So he decided to build a drone, and then he had a conversation with a co-worker about what to do with it. “The guy said, ‘you have to put Wi-Fi on this drone,’” he told DNews.
After a few false starts — he crashed at least one drone and destroyed a router before he got it right — he had his Wi-FI-capable drone. The whole thing cost only a hundred dollars to build, and would only be twice that if he’d paid for the router.
The quadrotor is a fun platform, Conway said, but it isn’t that efficient as it can only stay up for a short time. He wants to build one that can hover for more than an hour, or have two in tandem that could provide continuous Wi-Fi service. To that end he might eventually go with a more airplane-like design.
More seriously, there are many uses for a Wi-Fi drone. Certainly in a post-disaster scenario, such as after a tornado or hurricane, it would help rescue workers to have internet and phone access in places where many cell towers are down. For ordinary people it would provide Wi-Fi in places where there just doesn’t happen to be a connection that can link to a corporate VPN, more than one road warrior would find that useful for the extra security, rather than trusting the hotspot at a Starbcks.
For now though, he wants to have fun with it. “My goal is to provide Wi-Fi service at the next company picnic,” he said. “We haven’t been in places that let you fly remote controlled planes but I am lobbying for it.”
Credit: Adam Conway