Unmanned Haulers
Written by Peter Buxbaum
MLF 2011 Volume:5 Issue: 3 (April)
Cargo unmanned aerial vehicle concepts have been explored since the 1990s, but the United States military’s recent push toward deploying cargo unmanned aerial systems has sprung from the conditions it now faces in Afghanistan. Poorly developed roads over forbidding terrain has made resupplying remote forward operating bases very difficult. Even more so, the rash of improvised explosive devices (IEDs), which have exacted unacceptable numbers of casualties from the personnel manning resupply convoys, has led to the cry—get the trucks off the road!
To that end, the Marine Corps has awarded contracts to teams offering aerial unmanned platforms with an eye toward selecting one within the next few months and deploying the vehicle to Afghanistan soon thereafter. But the move toward unmanned cargo systems is not limited to that program. The Office of Naval Research, for example, is funding projects that push research in this area. Private industry is also making advances, while efforts are also underway toward integrating unmanned ground vehicles into resupply operations.
“We envisioned a real need for this capability when we first started working on it in 2007,” said Jim Naylor, director for business development for K-Max at Lockheed Martin. “We saw that warfighters would have to operate on limited potential routes to resupply points in remote areas. We also saw that they were being plagued by IEDs and saw the unmanned aerial system as a way to save lives and get warfighters out of harm’s way.”
The K-Max is a helicopter developed by Kaman Aerospace Corporation, whose capabilities were enhanced in partnership with Lockheed Martin. It is one of the platforms currently being considered by the Marine Corps.
The requirements identified by the Marine Corps call for an unmanned aerial resupply platform that is controlled from the ground. The Office of Naval Research is investigating pushing that technology to allow for greater autonomy for the platform.
“ONR is investigating and developing technologies to support autonomous aerial cargo delivery to distributed forces in combat,” said John Kinzer, an ONR program officer. “We are responding to capability gaps that have been identified through numerous studies of Marine Corps distributed operations and from reports of current operations.”
In August 2009, the Marine Corps Warfighting Laboratory awarded contracts to the Boeing Company and to Team K-Max, consisting of Kaman Aerospace and Lockheed Martin, to support a Marine Corps assessment for an unmanned aerial system to deliver cargo delivery in the austere and mountainous environments of Afghanistan.
Referred to as the Immediate Cargo UAS project, the effort is intended to demonstrate the state of industry’s current technological capability. Initial observations of the two platforms under consideration—Boeing’s A-160T Hummingbird and Kaman’s K-Max—took place at Dugway Proving Grounds in Utah in December 2010 and January 2011. Further assessments will be taking place before the winning platform is ultimately chosen.
The purpose of this effort is to expedite the deployment of viable technologies to the combat zone by delivering supplies from a main operating base to a forward position. The fielding of a cargo unmanned aerial system can also supplement existing aviation resupply efforts conducted by manned platforms.
The demonstration evaluated the abilities of the A160T and the K-Max to deliver at least 2,500 pounds of cargo in a six-hour period to a beyond line-of-sight location 75 nautical miles from a starting point. The Marine Corps’ desired capability is to deliver 10,000 to 20,000 pounds of cargo during a 24-hour period over a round trip distance of 150 nautical miles.
The two platforms under consideration are a study in contrasts. The A160 was developed as an unmanned multi-purpose platform. The K-Max is an adaptation of a manned system that has been hauling cargo in the commercial world for years. The A160 boasts high speeds and a smaller payload capacity. The K-Max has a greater payload capacity and was designed to be slow and steady.
“The A160 was designed from the ground up to be unmanned,” said Ernie Wattan, Boeing’s A160 program manager. “It brings fixed-wing performance to a rotor craft. It can operate in an austere environment with no takeoff runway. It is the world record holder for endurance in its class.”
The aircraft is capable of speeds of 142 knots, a level that Boeing is trying to raise to 165 knots. The 2,500-pound aircraft has a maximum takeoff weight of 5,500 pounds, which Boeing is now trying to expand to 6,500. The A160 also boasts “a very strong fuselage and a very strong rotor system,” said Wattan. “We are able to maximize the performance of the engine by running at lower RPMs and getting higher speeds.” The multi-mission A160 has also performed ISR work.
Lockheed Martin was looking for an unmanned aerial platform to develop for logistics purposes when it came upon the K-Max. “We chose it because it is perfect for this type of mission,” said Naylor.
Originally developed as a manned platform, the 6,000 pound K-Max can lift its own weight at sea level and 4,000 pounds at 15,000 feet. With maintenance costs of $1,000 per hour, “it is low cost to operate,” said Naylor. “We integrated our mission management and ground control capabilities to the K-Max to make it more robust.”
“Kaman has been working on our unmanned system for a number of years but our ground control station was rudimentary,” said Terry Fogarty, Kaman’s general manager for unmanned aircraft systems. “Integrating with the Lockheed Martin allowed us to improve the software and to add more components to have a redundant system.”
The aircraft’s intermeshing main rotors and lack of a tail rotor slows the speed of the aircraft—it maxes out at 100 knots unloaded and 80 loaded—but makes it easier to hover and to lift an expanded payload without a hydraulic system. The platform has extensive experience in the commercial world, most notably in the logging industry.
The K-Max’s cargo is held by a six-foot line, at the end of which is a commercial cargo hook or a carousel equipped with four separate hooks. “The purpose of the carousel is to load four distinct loads and drop at them at different locations,” said Fogarty. “It is a proven technology used in commercial applications today.
“This is a very low-cost platform because that is what the commercial market requires,” he added. “There is nothing fancy about it. We call it an unmanned aerial truck.”
The Office of Naval Research is working on a next generation vertical takeoff and landing (VTOL) air vehicle technology development in conjunction with the Army-led Joint Multi-Role Technology Capability Demonstration program. “ONR and NAVAIR are participating in this program,” said Kinzer, “which will explore concepts, conduct trade studies, and develop and demonstrate technologies for next generation rotorcraft.”
ONR is also planning a program in advanced autonomous capability for cargo unmanned aerial systems, called autonomous aerial cargo/utility system (AACUS), to begin in fiscal year 2012 and run through 2016. “The goal of this program,” said Kinzer, “is to develop and demonstrate revolutionary intelligent autonomous capabilities for a future aerial cargo and utility system that can provide timely, affordable, reliable and shipboard-compatible supply, retrograde and casualty evacuation. AACUS will use agile development processes with frequent laboratory and flight demonstrations.”
Lockheed Martin and Kaman Aerospace are already working on autonomous capabilities for the K-Max. “It can be programmed to fly from point A to point B,” said Naylor, “and can be reprogrammed en route to do an alternate route. It can take off and land autonomously and can complete a mission to a GPS way point, hover, put down and release a load, and continue on its flight path.”
Besides autonomy, ONR is also exploring a high-speed vertical takeoff and landing air vehicle, according to Kinzer. “As part of the high-speed VTOL effort, two vehicle concepts have been explored,” he added, “a fan-in-wing configuration with Northrop Grumman, and mono-tilt rotor with Baldwin Technology.” Follow-on small scale development efforts for these configurations are not currently funded.
Baldwin Technology’s air vehicle concept involves carrying the cargo suspended below the aircraft. “This has no effect on stability and maneuverability during flight,” said Doug Baldwin, the company’s president. “It does provide a smaller size, lower weight and more fuel efficient aircraft and that translates into lower costs.”
The lack of funding has stymied Baldwin’s efforts somewhat, but he continues to invest in the concept. “We know we can build a vehicle that will fly,” he said. “We need to understand if it is operationally suitable. Can it carry supplies to the point of need and return back to the ship?”
Baldwin’s current efforts are focused on vehicle autonomy. “There has been some breakthrough work on helicopter autonomy which we have brought in house and integrated into our simulation environment,” he said. “We have demonstrated these methodologies on a small remote control aircraft.”
Also on the drawing boards is an autonomous unmanned ground vehicle, called the Gladiator, developed by Carnegie Mellon University and BAE Systems North America. The first tactical unmanned ground vehicle, it was developed for the U.S. Marine Corps under a $26.4 million system development and demonstration contract from the U.S. Department of Defense’s Joint Program Office/Robotic Systems. Gladiator’s proponents anticipate that it could be deployed for a range of missions, including combat resupply, and also for searchand-discovery missions in hostile areas, urban battlefields, or minefields.
“Carnegie Mellon provided the robotics technology and overall design for the Gladiator, while BAE Systems and its partners manufactured the vehicle,” said Dimitrios Apostolopoulos, a senior systems scientist at the Carnegie Mellon Robotics Institute.
Gladiator is a tele-operated, semiautonomous vehicle that users can control through an interface display. “Gladiator is a smaller scale platform about the size of a golf cart,” said Apostolopoulos. “It is easily configurable and could be used for logistics support. It can carry quite a bit of payload,” on the order of 900 to 1,100 pounds.
Work on the Gladiator project began in 2002. Five platforms were delivered for evaluation in 2008. Since that time, Carnegie Mellon has been providing maintenance and technology support, but not much has happened in the last two years. “Interest appears to go up and down,” said Apostolopoulos.
“We thought the technology was wellconceived. It was not revolutionary but it did make some key advances,” he added. “One was that it could be adapted to multiple missions. Another was that the software was designed with safety in mind.”
The sensor and software equipped on the Gladiator prevents the vehicle from colliding with the Marines it is accompanying. If it is carrying a weapon, there are multiple controls in place to prevent misfiring.
Carnegie Mellon has also developed the software to make Gladiator more autonomous. Converting the tele-operated vehicle to an autonomous platform would require the addition of control software.
“I would like to see Gladiator deployed in the field,” said Apostolopoulos. “It provides good mobility and could be useful for logistics. It has excellent potential.”
As for the Marines’ current efforts, Boeing’s Wattan believes that “once they get the capability in theater, we’re going to be hard pressed to keep up with the demand.”
Wattan thinks there will be demand for the A160 elsewhere as well. That is why Boeing has actually set up a production line for the A160 in Mesa, Ariz., and has already turned out six platforms. ♦