Micro Air Vehicles Serve as Eyes in the Sky for Ground Troops

Honeywell Aerospace has developed the Micro Air Vehicle (MAV), an unmanned aerial vehicle (UAV) based on ducted-fan technology that recently was deployed in Iraq to identify improvised explosive devices (IEDs) from the sky. The deployment marked the first time a ducted-fan UAV was used during combat missions. The MAV, and subsequent generations of the vehicle already in use, could change the face of military reconnaissance, as well as help civilian law enforcement and aviation officials.

Birth of the MAV

The MAV program began as an Advanced Concept Technology Demonstration (ACTD) program in 2003, when the Defense Advanced Research Projects Agency (DARPA) awarded Honeywell a $40 million contract to develop the system. Over the past five years, DARPA has continued to invest in UAVs, particularly those with ducted-fan technology. While fixed-wing UAVs have existed for years, the military was searching for a system that would validate “hover and stare” capabilities — the ability to hover above a pre-programmed area and search for IEDs or other targets.

The ducted-fan technology was desirable to the military because it brought key aspects that had not been provided by fixed-wing UAVs. The first aspect was safety. All rotating parts of the MAV are contained within the duct, eliminating the free-rotor, open-spinning aspect that a remote-controlled helicopter might present.

According to Vaughn Fulton, program manager for Honeywell’s Small Unmanned Aerial Systems, that aspect was very desirable for the U.S. Infantry, which was the original proponent for the program. “They wanted a system that would provide persistent hover and stare capabilities; they thought that would be key to their mission and bring them the military utility necessary to have a UAV system down at the platoon level,” he said.

The idea was to develop a system that could be demonstrated in a representative military environment (meaning operating to a service ceiling of 10,500 feet), give it to a military unit, and have the unit develop the tactics, techniques, and procedures associated with the system. The military previously had flown fixed-wing systems and rotorcraft systems and determined that they were not safe enough. Prior ducted-fan systems were very large and not practical for soldiers on the move. The new system had to be small enough and light enough to be carried in a backpack.

Fulton explained that development was a two-phase activity. “The first phase was to prove that ducted-fan technology could be made small and robust enough for the military environment,” said Fulton. “That was our TMAV phase (Transitional Micro Air Vehicle). That phase was very successful — we demonstrated TMAV at Fort Benning, GA and at Scofield Barracks in Hawaii.” At Honeywell in Albuquerque, a system was demonstrated with a 10,500-foot service ceiling that was sized for a backpack, and was robust. “We went from a design concept to a flying vehicle in less than 12 months,” Fulton explained.

The lessons learned from the TMAV phase were incorporated into Honeywell’s current offering, called GMAV, which has gone through a military utility assessment with the 25th Infantry Division in Hawaii, and the National Training Center at Fort Irwin, CA.

How it Works

The MAV operates like a remote-controlled helicopter and can hover and stare, flying down to inspect hazardous areas for threats without exposing soldiers to enemy fire.

The U.S. Infantry defined the original Honeywell MAV system, which consists of two air vehicles that typically fly between 10 and 500 feet above the ground. One is an electro-optical (EO) system with daylight cameras, and the other is an infrared (IR) vehicle, with both daylight and low-light capabilities. There is a common ground station between the two air vehicles that features an operator control unit (OCU) and a ground data terminal with a GPS system, radios, and antennas that connects to the operator control unit. The ground station can be used to program a flight path for the MAV or control it manually.

Each MAV is small enough to carry in a backpack and is equipped with video cameras that relay information back to foot soldiers using a portable handheld terminal. The circular vehicle weighs about 16 pounds without fuel (18 pounds fully fueled) and measures 13" in diameter.

It operates like a small remote-controlled helicopter and can easily fly down to inspect hazardous areas for threats without exposing soldiers to enemy fire. The MAV also has the unique ability to take off and land vertically from complex desert and urban terrains without using runways or helipads.

The system is fully autonomous. A sequence of waypoints is programmed into a flight plan, which is loaded into the vehicle. The vehicle will fly that flight plan fully autonomously. At points of interest, the user can take manual control of the vehicle and tell it to stop, rotate left or right, or go forward or backward. The vehicle can fly at speeds of 60 miles per hour or more for more than 50 minutes.

According to Fulton, it can fly orbits and patterns much like a fixed-wing craft, “but the real capability that it gives beyond a fixed-wing system is that you can find a waypoint, have it stop at that waypoint, stare at a certain bearing and direction, and collect information,” he explained.

If there is no defined flight plan and a user is in the immediate area and needs to see over the next hill or around the next corner, the system can be launched without a flight plan. It will go through its automated launch sequencing and hover over its takeoff point at 50 feet, waiting for the operator to give it manual commands.

“It’s a very modular system,” said Fulton. There is a center body with the engine and the vanes; there is an avionics pod, with the flight management unit, the inertial measurement unit, and the avionics circuitry; and there is a payload pod with the GPS receiver, the uplink and downlink radios, and the sensors themselves — the daylight and IR cameras. “We put together pod configurations to add various radios in them that operate in various frequency bands based upon the mission the vehicle is flying,” Fulton added. Various sensors, both IR and EO, were added, as well as EO cameras and field-of-view IR cameras.

Part of the ACTD trials were in-placement trials — getting it in place and airborne. “One of the portability goals was to place the system and have it airborne in less than five minutes,” explained Fulton. “An operator who has received three days of classroom training and two days of flight training can deploy the system in less than five minutes.”

Testing and Implementation

Since 2004, the U.S. Navy had been looking for an airborne component for their suite of robotic vehicles. The Navy’s ordnance disposal team’s primary mission is the improvised explosive device fight, primarily in Afghanistan and Iraq. They wanted a sensor platform they could use in conjunction with their ground robotic platform. According to Fulton, “There are situations in which their ground robots could not get to things, and a hover and stare platform like the one we had could get there. They had explored using three-rotor helicopter systems, and could not come up with a viable solution.”

For the IED deployment in Iraq, Honeywell built 20 air vehicles, and all 20 deployed to Iraq. For the military utility assessment, the company built 50 air vehicles, and those have been in the possession of the 25th Infantry Division. “They’ve been doing various activities with those vehicles — training and utility assessment. Deployment with the IED was the first real-life deployment,” according to Fulton. It also marked the first time a ducted-fan UAV was used during combat missions.

In the first quarter of 2006, Honeywell demonstrated TMAV to the Navy, and later that year, Honeywell validated what combining an air robot such as the MAV with the Navy’s ground robot could do. Said Fulton, “They subsequently did a deployment in theater with a system including the GMAV, and had very good results with it. They are moving toward their own program relative to an air- and ground-centric system.”

Honeywell recently received two contracts from the U.S. Navy totaling $7.5 million for the manufacture of more than a dozen MAV systems, as well as training and deployment support in Iraq. A subsequent $61 million contract was awarded last summer as part of the Army’s Future Combat Systems program.

Honeywell’s MAV system has been field-tested by the 25th Infantry Division in Hawaii. It has flown more than 3,500 test flights over the past three years. The U.S. Infantry, through both the Future Combat System (FCS) and the work Honeywell has done through their ACTD, is looking to deploy the current GMAV with some improvements, and also further elaborate on the ducted-fan capabilities with their FCS Class 1 vehicle.

The MAV conducted its first successful international test flight in Bourges, France on March 28 of last year. It also participated in a successful hostage rescue scenario last May. “We have demonstrated both to the UK and France and other NATO countries where this technology can be exported,” said Fulton. “We have plans with NATO allies, and we’ve sold a system to the Miami-Dade Police Department. We have both military and civil customers. We expect multiple deployments with various components of the U.S. military, and 2008 will bring several more deployments of GMAV,” he said.

The Miami-Dade Police Department is the first entry into the civilian law enforcement market. The Miami-Dade Police Department and the Federal Aviation Administration (FAA) are working together in an experiment to lay the ground work for how these systems can be used in the national airspace. “That’s the real key,” said Fulton. “The military flies in restricted airspace, and through this activity, we’ll be flying MAV in the national airspace. They will be looking at how a system like this could be employed by police departments and still maintain the integrity of the system that the FAA has put together to keep manned flight in the national airspace safe. It’s a very exciting opportunity for Honeywell, and one that will lay the ground work for how other police departments will employ systems like this.”

Fulton attributes the success of the MAV program to the advent of microelectromechanical systems (MEMS) technology, coupled with the lineage of Honeywell flight controls. “The interesting thing is that ducted-fan technology has been around a long time — you can go back and find ducted-fan systems being flown in various configurations in the early 1950s,” he explained. “Previously, without the processors to run very complicated flight controls, the systems were just not viable. Now, being able to bring those two disparate pieces of technology together into a small package is what made it a success.”

The future MAV will integrate additional sensors including a gimbaled sensor. “We are now flight-testing our new gimbal sensor for the platform, which brings another level of sophistication and detail to the type of situational awareness data that you can get from a platform like this,” said Fulton.

For more information on Honeywell’s Micro Air Vehicles, click here  .