Progress Through Versatility
Will Optionally Piloted Vehicles Change the UAV Market?
By George Jagels
In April 2014, The Office of Naval Research (ONR) announced successful demonstrations of its Autonomous Aerial Cargo and Utility System (AACUS). This open architecture platform is designed to enable new and legacy rotary aircraft to launch rapidly “from sea and land, fly in high/hot environments, and autonomously detect and negotiate precision landing sites in potentially hostile settings,” according to ONR.
Short-term, ONR’s goal for AACUS is to provide reliable resupply. Long-term, the system will be used for casualty evacuation by an unmanned air vehicle (UAV) in poor weather.
In videos released by ONR, Marines with no training are shown how to operate the system on a tablet computer, and they easily direct K-MAX and Little Bird helicopters to take off, fly a route, and land. Autonomous software determines the best landing spot— without the intervention of a pilot.
On 11 March, Sikorsky Aircraft Corporation successfully tested its Matrix Technology on an unmanned Black Hawk in a resupply role. Such rotorcraft, known as optionally piloted vehicles (OPVs), are being developed by some of the world’s largest helicopter manufacturers, including Sikorsky, Kaman, Lockheed Martin, Boeing, Agusta Westland, and Eurocopter.
The U.S. Army has a program that’s similar to AACUS. The DoD’s Future Vertical Lift program wants autonomous flight capability to be part of whatever next-generation helicopter it chooses to build. Optionally-piloted aircraft may seem revolutionary, but the future is powered by the past.
Cultural Challenge, Practical Advantage
During the AACUS demonstrations, two helicopters were manned by pilots to reduce program risk. This may indicate more than a cautious attitude, however. “Even if the totally unmanned vehicle is capable of carrying troops, there are certain cultural bounds that won’t let that happen for some time,” said Igor Cherepinsky, chief engineer for autonomy at Sikorsky. Mission operators in the cockpit can help counter this concern, and an OPV can deliver cargo without a pilot.
The aircraft themselves represent a different way of looking at UAVs and autonomy. Crash rates are much higher for UAVs than traditional aircraft. So as OPV makers plan to transport people, manufacturers are finely focused on reliability and redundancy, as indicated by the use of very well-regarded platforms such as the Sikorsky S-76, Kaman K-MAX, and Boeing Little Bird. Reliable vehicle control is a critical component of successful autonomy.
“There is also an ongoing mentality change to realize that the loss of a UAV … creates a risk for those that depend on the data or capability they provide,” said Dino Cerchie, program manager for the Unmanned Little Bird (ULB) at Boeing. “Therefore, UAVs will not be considered mission expendable in the future and therefore will need to be more reliable.”
Another practical advantage in having the option of an aviator in the cockpit is a significant reduction in legal and technical hurdles, explained Terry Fogarty, who works in business development for the K-MAX at Kaman. “Having a pilot allows you to fly in the national airspace regardless of whether someone else is controlling the aircraft,” he said. “We were also able to take bigger leaps in software technology because if anything went wrong, the pilot was there.”
Kaman and Lockheed partnered on the unmanned K-MAX in 2007. The platform was designed specifically for sling load cargo operations in the 1990s. Since then, it’s performed a similar mission autonomously for the U.S. Marine Corps in Afghanistan for over two years.
Resupply and retrograde missions are sometimes boring and often dirty, Fogarty noted, which makes them ideal for inherently reliable OPVs. Though a K-MAX crashed in Afghanistan last year, the aircraft have been available to fly 90 percent of time.
Software, Sensors, and Operators
Autonomy software varies widely between companies, and the details are tightly held. In general, however, OPVs are given directions by GPS coordinates from the mission controller, who can specify no-fly zones, altitude, and speed. Fogarty claimed that a K-MAX sling load can be landed within one to three meters of the coordinates given.
For flexibility, OPV software, like that in the AACUS program, is “agnostic,” meaning it can be modified and used with other platforms. Describing the ULB, Cerchie said that Boeing’s program was made possible by leveraging the “control laws” of autopilot programs coupled with navigation accuracy improvements. “The key is always in the baseline architecture of the design to not only provide a capability today, but to support integration of new capabilities into the future,” he added.
Sensors are also being integrated into these aircraft to improve perception. One of the many goals of Sikorsky’s Matrix Technology program is to integrate affordable sensors with OPVs to improve vehicle performance in all conditions. “We believe we’ve found a robust solution for perception to get the data into the system, and are developing the algorithms to go along with it,” Cherepinsky told UTS. He added that Sikorsky has successfully tested the sensing and control algorithms on its demonstrator S-76.
Each of the three models mentioned above can be controlled by line-of-sight antennae or satellite data links, allowing flight control from anywhere in the world.
The amount of time that’s needed to train operators varies. Fogarty noted that while Marines can operate the K-MAX after just one to two weeks of training, civilians who train and work with the system for longer periods are noticeably more adept. Cerchie added that an operator should pass the ground segment associated with a pilot license, and that “there is a strong case that the operator should also be trained as an air traffic controller because the UAV operator task is becoming more an issue of airspace de-confliction with other aviation traffic rather than flying the aircraft.”
Is the autonomous OPV destined to only perform mundane tasks? Not necessarily, as the U.S. military is clearly interested in “smarter” helicopters.
Demonstrating its potential for more complicated missions, the K-MAX ran an important test with the Army’s Autonomous Technologies for Unmanned Aerial Systems program last year in which autonomous laser radar and obstacle avoidance systems were successfully used.
This summer, Sikorsky will experiment with a medevac mission in which a medic uses a tablet to request an OPV. The vehicle will then fly low and fast while avoiding obstacles—demonstrating its perception system and battlefield utility. Cherepinsky said the helicopter should be able to optimize the landing spot based on both its ability to land and the medic’s needs.
“Aircraft already have a certain level of physics-based autonomy, with a flight plan and so forth,” Cherepinsky said. “We want to take the next step and allow human beings to do what they’re best at: running the mission. So folks that operate medevac missions can be medics, and the machine is taking them to and from the trauma center.”
This leads to mission autonomy, in which the operator specifies intent or goals rather than how a vehicle should run the mission. Certifying that a system can do this reliably and safely, Cherepinsky said, is essentially impossible today; however, his company is working with military and civilian personnel on this issue.
The medevac role appears to be the next step for OPVs, but other roles are also available and needed. Boeing has demonstrated manned/unmanned teaming and shipboard operations, for example, and an armed ULB appears feasible, though weapons use would not be autonomous. Cerchie captured the sentiment of inevitability shared by Cherepinsky and Fogarty about OPVs.
“The ULB has all of the characteristics that current customers want out of their UAVs,” the Boeing engineer said, “and when platform decisions are made based on economics and getting the job done, then the market will be ready for the ULB.”
Lead Art: Sikorsky demonstrates advanced cargo resupply on a Black Hawk using a tablet-like device under the control of two ground station operators. (Sikorsky)
This article first appeared in the May 2014 issue of Unmanned Tech Solutions magazine.