Robots with guns: Army researchers address challenges of remote lethality
By Ed Lopez, Picatinny Arsenal
In popular culture, the idea of robots that perform human-like functions has a special hold on the imagination, based on real-life examples like space exploration, unmanned aerial drones and stoked by futuristic scenarios in movies like the "Terminator" series.
The military has used and experimented with robots that perform functions such as scouting and surveillance, carrying supplies and detecting and disposing of improvised homemade bombs.
However, when it comes to integrating lethality, such as a weapon capable of firing 10 rounds per second onto an unmanned ground vehicle, issues arise such as safety, effectiveness and reliability, as well as military doctrine on how much human involvement is required.
While conducting a Gunnery Exercise the Ripsaw Unmanned Ground Vehicle engages a stationary BMP target at a distance of 700 meters, using the M2 .50 caliber machine gun. [Photo Credit: U.S. Army photo]
Robert Testa, the technical lead of the Remote Weapons Branch at Picatinny Arsenal, New Jersey, recognizes the growing evolution in autonomous technologies and is focused on improving existing remote weapon technologies for manned and unmanned platforms, as well as fixed-site applications.
Testa, whose branch is part of the Armament Research, Development and Engineering Center, referred to as ARDEC, said the term supervised autonomy strikes a contemporary balance between schools of thought that range between total human control (tele-operation) and researchers who are developing the technologies to enable robots to think for themselves.
Tele-operated means a human makes all the decisions regarding the activities of a remote platform, which is linked to the operator through a radio frequency or a physical link such as copper cable or fiber.
Regarding the term supervised autonomy, Testa said, "I believe that UGV (unmanned ground vehicle) and robotic platform developers apply the term supervised autonomy because not only do robust fully autonomous ground platforms still require substantial development, but it is essential that any UGV have the capability to react to command and control from a human operator under certain circumstances.
"This is similar to the addition of limited autonomy to RWS (remote weapon systems), but our primary focus has to be the robust, real time, tele-operation capability to ensure safe and effective weapon operation, regardless of the platform or application."
The term -- supervised autonomy -- also reflects the current state of technology.
Testa favors the term unmanned ground vehicle, which can encompass either a tele-operated platform or a robot with varying degrees of autonomy, as a way to distill the mission of the remote weapons branch at Picatinny with respect to remote lethality.
"There are some areas where we and our partners are developing the capability to add degrees of supervised autonomy for weapon systems, but we recognize that you will always require real-time manned supervision of what the RWS is aiming at, what targets are engaged, and when that engagement takes place, i.e, trigger pull," Testa said.
Army research into remote lethality complies with Department of Defense Directive 3000.09 "Autonomy in Weapon Systems," published in November 2012. The protocols reflect the current doctrine addressing all classes of remote and unmanned weapon operation designed to allow commanders and operators to exercise appropriate levels of human judgment over the use of force.
"We can easily enable current generation remote weapon systems to aim and engage targets autonomously," Testa said. "Yet current doctrine and the realization that current sensor and processor technologies would provide little or no assurance to what was engaged, keeps the real time tele-operation mode of weapons use at the center of what we develop and demonstrate today.
"Today's current remote weapons systems are primarily developed and deployed as tele-op weapon systems, yet they inherently lend themselves as the starting point for the future of UGV lethality," Testa continued. "The [Remote Weapons Branch] is working to make remote weapons more remote."
"The two primary facets of the [Remote Weapons Branch] research are to develop advanced functional capabilities for the weapon system and the development of the system architecture and communications between the operator and the weapon, enabling development of extension kits that can support various transmission media such as radio frequency or a physical link such as optical fiber."
Researchers are aware that the term remote weapon may evoke an image of something operating many miles away, with a high degree of autonomy; however, remote could also mean a weapons system on top of a vehicle with the operator inside under the protection of armor.
At ARDEC, a remote weapon system is closely associated with something like the fielded Common Remotely Operated Weapon Station, also known as CROWS.
CROWS is a stabilized mount that contains a sensor suite and fire-control software. It allows on-the-move target acquisition and first-burst target engagement. Capable of target engagement under day and night conditions, the CROWS sensor suite includes a daytime video camera, thermal camera and laser rangefinder.
CROWS supports the MK19 Grenade Machine Gun, the M2 .50 Caliber Machine Gun, M240B Machine Gun and M249 Squad Automatic Weapon, weapons originally designed for manned operation. The system has been integrated onto more than 20 platforms, from the Humvee to the M1 Abrams tank.
Yet current-generation remote-weapons systems as CROWS cannot support other functions essential to making remote weapons more remote.
The ARDEC-developed Advanced Remote Armament System, or ARAS, has additional capabilities, such as an externally powered, purpose-built weapon to improve reliability and accuracy, the ability to load and clear the weapon remotely and an increased stowed ammunition load without decreasing aim or stabilization. It can also reload the weapon or change ammunition type without manned intervention at the weapon, in approximately six seconds.
Also critical for future asymmetric engagements is the ability to change from lethal to non-lethal ammunition that ARAS provides. ARDEC has developed both 7.62mm and .50 caliber ARAS prototypes. The ARAS patents are owned by the U.S. Army, which enable cost-effective acquisition once future requirements are generated.
Although ARDEC does not develop vehicles or platforms for its weapons, it has used a tele-operated MS3 Ripsaw as a "surrogate platform" for the development of UGV lethality technologies, including wireless extension kits for CROWS, ARAS and other remote weapons systems.
These programs have culminated with the first unmanned ground vehicle Scout Gunnery Table VI experiment in November 2013, at Fort Dix, NJ. ARDEC also works with other government and industry partners to weaponize UGV platforms.
While some UGV functions may include such things as carrying equipment, surveillance or removing homemade bombs, their functions are not lethal in nature. But incorporating powerful weapons onto a UGV presents a number of technical challenges, including minimizing or eliminating latency.
Advanced Remote/Robotic Armament System, 7.62-mm Prototype. [Photo Credit: U.S. Army photo]
Latency means delay or the time elapsed between using controls to initiate an action and when it actually happens. This is particularly critical when you have high-rate-of-fire weapons, Testa said.
Latency also applies to video, or the time elapsed between the images captured by a RWS mounted camera and when they actually appear on the screen of the operator.
"Latencies are bad, and they are technically challenging, especially video latency," Testa said. "Our goal is to minimize video latencies as much as possible and we are targeting a maximum of 250 milliseconds, or quarter of a second."
Testa said humans start to notice latency at around 250 milliseconds. "You start to sense, 'I moved the joystick, but I didn't see the reticle move right away.'"
"You want your video to be real-time as much as your controls are real-time," explained Testa. "I pull the trigger, I want the gun to shoot immediately or close to it as possible, but I also want to know what I'm looking at as close to real time as possible."
The lethal nature of a weaponized unmanned ground vehicle, and the need to keep latency to a minimum, are reasons that a robust connection from the operator to the remote weapon system is critical, whether that link is by radio, fiber or copper.
Testa said that when people hear about predator drones hitting their targets while the operator is halfway around the world, that may leave the impression that something similar can occur with remote weapons systems on the ground.
"They are using satellite communications with a fairly large latency," Testa noted of such drones. "We're shooting machine guns in a cluttered and asymmetric ground environment. That makes the problem a lot tougher in some ways. Drones are targeting for and launching one missile that has guidance to the threat. We are shooting dumb bullets at 10 per second, so we don't have a lot of wiggle room."
A futuristic vision of a fully autonomous robot that thinks and acts independently would essentially take human judgment out of the equation, and possibly without a real-time communications link to support supervised weapon operations.
"Where we are with the weapons side today is tele-op; I need to be able to talk to my weapon," Testa said. "An autonomous UGV that could keep driving, increasing range, would lose that tele-op capability, in which case we would no longer have man-in-the-loop with the weapon -- that is still unacceptable per DODD 3000.09. So currently we are constrained by radio function and that limits our range. Radio technology is also largely driven by the commercial market, and we need to keep an eye on our overall system cost."
Testa said remote weapon systems require relatively high bandwidth and a continuous flow of data to the RWS, so that it doesn't result in continuous dropped messages, which could cause the system to reduce capability or shut down altogether.
"If a Soldier is engaging a threat to save himself and his buddies, he can't afford dropped messages to the point that the weapon often stops shooting," Testa said.
ARDEC engineers have been working on fiber and radio frequency extension kits that would increase the range of remote weapons systems.
"We believe that it's very hard for somebody to decipher our messages to the point where the enemy could turn our systems against us even if they are not overly encrypted," Testa said. "But we're not currently addressing encryption methods, and the development of these capabilities lies outside of the expertise of the ARDEC remote weapons branch.
"It doesn't mean certain degrees of encryption or jamming prevention couldn't or shouldn't be built in," he said. "It is not our focus right now nor is it core ARDEC mission. Our mission is to address how an RWS behaves when a cable is cut, or [radio] messages are temporarily lost."
The simple theory is, 'When you lose the link between the operator and the weapon, the system will stop doing what it's doing and won't start doing something it's not,'" Testa explained.
The technological sophistication of the enemy, or the theater of operations, would be factors to consider regarding encryption, jamming and frequency allocation, Testa said, but technical research dollars are too limited to engage in speculation about what a specific theater and battlefield scenario would require.
The ARDEC Remote Weapons Branch partners with other DOD organizations on the research, development and testing of technologies to add degrees of supervised autonomy for integration with advanced remote weapons systems.
This article appears in the November/December 2014 issue of Army Technology Magazine, which focuses on robotics. The magazine is available as an electronic download, or print publication.
Published December 2014
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