Bigger isn't always better
Micro-unmanned vehicles invade the military on the ground and in the air.
There's a new breed of unmanned vehicle in town, and they can be launched, tossed, or operated with just one hand. These pint-sized vehicles (though many of them are smaller than that) are called micro unmanned vehicles, and they have begun seeing a surge in popularity.
Offering utility on demand, micro unmanned vehicles represent a situational-awareness revolution for warfighters by giving them the information they need when they need it.
When a warfighter must find out what is beyond the next hill, he may be able to reach into his pack and launch an unmanned aerial vehicle (UAV) no larger than a hand to take a look for them. When a warfighter needs to know what is inside a building, he simply can throw a small, rugged unmanned ground vehicle (UGV) through a window and take a look around remotely.
These vehicles can help complete some of the most dangerous tasks warfighters face today by providing information that can save lives and even trigger improvised explosive devices (IEDs).
With technology moving forward, man- packable vehicles stand to become even smaller and lighter, and are discovering use in new applications.
Why micro?
"When you're walking around with everything on your back, weight is critical," explains Ernest Langdon, director of U.S. military programs at ReconRobotics in Edina, Minn. "These guys are carrying in excess of 100 pounds. I think the belief is ounces make pounds and pounds make pain."
Warfighters today carry radios, food, ammunition, water, weapons, optics, and more, all while wearing heavy body armor. Carrying an additional 20 pounds just isn't an option for warfighters.
The solution is micro unmanned vehicles that weigh just a few pounds, or even a matter of ounces. Having a lightweight system enables warfighters to carry them into combat and deploy them when they are needed.
Traditional UAVs, such as Predator drones or Global Hawks, don't send information directly to the front line. Instead, these larger systems report to officers further in the rear, which can delay crucial information flowing to front-line warfighters. Rather than waiting for a large unmanned system, warfighters today can carry an unmanned vehicle into combat and have it up and transmitting information in minutes.
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The Hummingbird micro UAV uses flapping wings to propel itself. The micro UAV is a technology demonstrator designed to fly indoors
Micro UGVs
Micro unmanned ground vehicles (UGVs) have wheels, treads, or a combination of both. There is no official micro unmanned ground vehicle definition, but the general consensus is a vehicle that weighs no more than 10 pounds and can be held, or thrown, with one hand. The utility of these unmanned vehicles comes from their durability, portability, and mobility. They are designed to go into dangerous areas and provide surveillance capability to their operators.
"The main purpose of unmanned vehicles from a military standpoint is dirty, dull, and dangerous," says ReconRobotics's Langdon. "They're trying to create standoffs between troops and the things that can harm them. It will get to the point where it's unacceptable to send a person when you can use a robotic system to do that really dangerous stuff."
Micro UGVs help military personnel investigate, disarm, or even trigger suspected IEDs without putting humans at risk. These vehicles are built to be hurled into buildings, withstand explosions, and keep on rolling no matter what comes their way. The micro versions have an additional use of being able to provide situational awareness. Rather than going into builds blind, micro UGVs can be tossed into the building or driven through the entrance, enabling warfighters to obtain situational awareness that would otherwise not be available to them.
Because of the many uses for micro UGVs, different vehicles feature wildly varying designs, ranging from treads designed to climb stairs, payloads with a robotic arm to disable or trigger IEDs, sensors for chemical and biological agents, and other equipment. Operators can swap these payloads on the fly, enabling the system to change based on the task at hand.
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A Recon Scout micro UGV by ReconRobotics moves across unsteady ground. Micro UGVs are built to traverse rugged terrain
Micro-UAVs
Full-sized UAVs are already well known for their ability to provide situational awareness and even attack targets. Micro UAVs tend to be smaller than 10 pounds while serving specialized purposes.
"With small unmanned aircraft systems, front line warfighters can deploy them wherever and whenever they need them, to see what they need to see," says Steve Gitlin, vice president of marketing strategy and communication at AeroVironment in Monrovia, Calif. "They give the operator the ability to find out what's on the other side of the hill or ridge, or ahead of the convoy."
For micro UAVs, weight and size are of greater importance than micro UGVs. "Weight is king in this realm," explains Shawn Prestridge, senior field applications engineer at IAR Systems in Plano, Texas. "Less size means less weight, which in turn means you need less of a motor. This can lead to more payload and lighter designs."
Micro UAVs also feature a wide variety of designs. There are single-, double-, and quad-rotor micro UAVs, fixed-wing micro UAVs, and even vehicles that use flapping wings to stay airborne and provide control. Since the technology is so new, there is no consensus among designers over which method of propulsion is superior, and the missions that these vehicles fly vary as much as the designs.
A fixed-wing micro UAV typically will look at areas beyond the next hill, or provide surveillance over a large area. Rotorcraft are used for persistent surveillance of a smaller area, or even as a way of providing surveillance of a building. The type of vehicle carried on a mission depends on what tasks warfighters expect to accomplish.
Power issues
Micro unmanned vehicles have one large problem that is the result of their form factor: smaller vehicles mean smaller payloads, along with a smaller battery and motor. This means micro unmanned vehicles have short operating distances, limited utility, and a short operating life. While modern, full-sized unmanned vehicles can run for days at a time on one charge, micro unmanned vehicles often run out of power in hours or minutes.
Conserving energy is of the utmost importance to increase the operating life of micro unmanned vehicles. This is of particular importance to micro UAVs, which need their motors to run continuously to stay airborne. "The lower the UAV's power profile, the more time you have with the airplane actually up in the air flying," says IAR Systems' Prestridge. "So tools that enable the developers to highly optimize the code are invaluable. By using good coding practices, you can save up to 35 percent of the power being used by the microcontroller."
In addition to optimizing code to reduce the power draw of electronics, new battery solutions are being considered. Fuel cell technology, which has seen experiments in the unmanned underwater vehicle theater, is being looked at as a possible life-extending solution for micro unmanned vehicles on the ground and in the air. Currently, only traditional batteries are in use for micro systems.
Cost is king
Micro unmanned vehicles are meant to be expendable and portable, and to operate in dangerous conditions, so cost is important. "Cost is always a big issue," explains ReconRobotics's Langdon. "The budget is getting tighter, and the government is trying to save money. If you can have an 80 percent solution that is 10 percent of the cost that would be the smart decision to go with."
Because of how important cost is to micro unmanned vehicles, they are built primarily using commercial off-the-shelf (COTS) parts. Miniature cameras, motors, and computer systems that can be purchased from major electronics retailers are used by these tiny vehicles. By using COTS products in micro unmanned vehicles, as technology prices decrease, so too does the cost of the vehicles. This enables micro unmanned vehicles to be inexpensive enough for groups of warfighters to use the vehicles in dangerous situations.
Safety and security
"To be that cheap, they use quite a bit of COTS components," says IAR Systems' Prestridge. "However, when you use COTS, you have the problem that a clever enemy can use it against you. It begs the question, 'How do you actually secure it?'"
Since micro unmanned vehicles are constantly transmitting information to their operator, and the operator is sending instructions to the vehicle, opposition with an understanding of the technology can take control of unsecured vehicles. This is an area where the vehicles' short battery life and operating range is an advantage, enabling most forms of encryption to be used due to the time taken for their signal to be picked up by the equipment needed to crack its encryption and take control of the system.
Users of micro unmanned vehicles need to worry about more than just network attacks. Users need to be concerned with physical fire, as these vehicles operate near enemy forces.
Due to the missions they perform, these vehicles are designed to be an expendable resource. Micro UAVs fly low to the ground, and rely on their size and visual camouflage to avoid detection. Micro unmanned ground vehicles rely on stealth to avoid detection and rugged design to enter areas that may not be safe for humans and survive physical trauma.
Swarm technology
Micro unmanned vehicles are also capable of working together in ways that other systems can't. Autonomous unmanned vehicles can be used together to perform surveillance of an area or other missions that one vehicle could not perform on its own. "Requirements are being developed for multiple vehicles to work collaboratively to ensure a mission is successfully completed," says Jim McElroy, vice president of marketing at software expert LDRA in San Bruno, Calif. "In the future, we could see swarms of autonomous vehicles participating in coordinated surveillance, reconnaissance, and battle-related activities."
Swarm technology eliminates one of the main weaknesses of micro unmanned vehicles: their vulnerability. While a lone micro unmanned vehicle is easy to destroy or disable, a swarm of micro unmanned vehicles can accomplish the mission even if several vehicles are lost. One of the many applications for swarms of micro unmanned vehicles is attacking missile launchers, bunkers, and other stationary sites. Rather than send in ground troops or pilots, autonomous, armed micro unmanned vehicles can go in sufficient numbers to overwhelm enemy positions.
Offensive applications
Micro unmanned vehicles, particularly in swarms, have potential to perform tasks other than situational awareness. Low-cost micro unmanned systems can be armed and are being tested as self-destructing weapons that don't put operators or expensive equipment in harm's way.
The problem with offensive micro unmanned vehicles is cost. Armed micro unmanned vehicles "need to provide high-performance sensory functions while at the same time being cost effective to produce," says LDRA's McElroy. While larger unmanned vehicles can afford to have sophisticated equipment for target detection and verification, as they are not highly expendable, micro unmanned vehicles do not have the same luxury and must wait for high-quality sensors to become low cost.
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The Datron Scout ARS micro UAV is designed to provide situational awareness.
The future of micro unmanned vehicles
Micro unmanned vehicles are a young technology, having only become viable in recent years, and are still far from becoming popular. As technology continues to shrink, the applications micro unmanned vehicles can be used for becomes vast.
"Micro-unmanned vehicles are only going to get better and smarter," says ReconRobotics' Langdon. "They're going to be doing stuff for the military, law enforcement, and commercial applications. I think you'll see them in any high-risk environment, dirty, dull, and dangerous. If I need to monitor something continuously, I'll use a robot."
As technology moves forward, it will continue to shrink and become less expensive, and with cost as one of the major limiting factors of micro unmanned vehicles becoming a standard part of a squad's equipment, it won't be long before the tiny vehicles see deployment more frequently.
"It's an exciting space," says AeroVironment's Gitlin. "We're at the beginning stages of the adoption of this technology."
Bigger isn't always better - Military & Aerospace Electronics
