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May 2005

Soldiers Teaching Robots Battlefield Duties

By Joe Pappalardo

Sgt. 1st Class Ralph Brewer has an odd job that is at the intersection of past and future warfare—teaching a robot to be a combat reconnaissance scout.

“An Army field manual can tell you how you should do it,” he says. “When you get out there and do any type of mission, it’s not ever the same … There are ways of doing things the book doesn’t show you.”

Brewer’s work is part of an Army Research Lab’s effort to instill robots with complex behaviors, thus, making them suitable for the battlefield. At the lab, a dedicated effort is under way to create the perfect unmanned reconnaissance scout.

To perform the mission the robots need two things: sensors and good programming. They must be able to read a situation quickly and safely, whether it be moving over obstacles or navigating a course through coming vehicle or pedestrian traffic.

“Those in the military know there is a lot more to being on a road recon mission than moving from A to B,” says Charles Shoemaker, head of the lab’s robotics program office. “There is the traffic on the road. They’re looking for ambush points and bridges that need to be intact.”

ARL develops robotic platforms, hardware and software, that can transition into other government research programs, such as the Army’s Tank-Automotive Research, Development and Engineering Center. The research lab’s imaging technology, which uses laser radar to capture local environments, is being used on various robotic programs at TARDEC. Each of those vehicles is part of Future Combat Systems.

The laser radar sensors themselves have been honed to increase their range, accuracy and security. “Earlier generations could be detected by night vision equipment. We have lowered the emission frequency so that it can’t be seen,” Shoemaker tells the audience at a recent industry conference.

Sensors are vital to creating flexible robotic behavior. But the Army Research Lab is teaching the behaviors. It is starting with using them to pave the way for convoys and infantry patrols. “There are many specific tactical behaviors the military wants to integrate,” Shoemaker says. “We’re focused on one—route reconnaissance.”

The construction of a behavior begins with the textbooks. Instructional materials are condensed to simple instructions, a series of decisions a robot can process. Or, as Shoemaker puts it, “that information can be knowledge-engineered.”

Say a robot is approaching an intersection on a recon mission. In a structured, methodical way, the machine must know the factors to which it needs to react. Static features such as walls and roads are easy. What are more complex are the calculations needed to steer around pedestrians, observe stop signs, scan suspicious items and plan an optimal route. Avoiding oncoming traffic requires a system that can plot the course and speed of oncoming vehicles and determine if it can proceed without a collision. “We build predictive dimensions … that help drive the robots’ decision-making,” Shoemaker says.

However, it takes knowledgeable people to train a robot. “When we enter an intersection, we know what to look for,” says Shoemaker. “But anyone who’s taught an adolescent to drive knows this is not always obvious.” These subtleties must be taught by professionals, in this case two experienced NCOs at Aberdeen.

That’s where Brewer, a veteran scout, comes in. “We go through scenarios with them, changing things,” says Brewer. Changing conditions, ranging from weather and roadside bomb detection, can be programmed into the matrix of details on which the robot needs to train its sensors. Data from unmanned air vehicles can also be integrated into decision-making.

Often, designs of robots require them to make quick decisions. The Defense Advanced Research Projects Agency funded the creation of an unmanned wheeled vehicle, called Spinner, which can take one-foot obstructions at 20 miles per hour without damage. Any larger obstacle, however, needs to be avoided.

This requires a perception integration suite that allows the vehicle to scan and react to such obstacles. Other decisions need to be made regarding power. When taking a steep incline, the machine can draw on its batteries for an extra boost.

DARPA also is commissioning robots that navigate on legs, rather than wheels. That requires a number of different approaches the machine takes to overcome obstacles.

A gas-engine powered quadruped, called Big Dog, has been constructed under the agency’s auspices by Boston Dynamics, Inc. The company builds robots and instills in them the behaviors necessary to navigate on legs. “The key idea is balance,” says Robert Playter, vice president of engineering. “They have sensors just as we have our inner ears.”

When the robot’s leg is raised, internal sensors are converted into feedback control algorithms that help determine the location of the machine’s next step. This programming preserves forward movement and maintains balance. In this way the robot can move autonomously. “All the things people and animals take for granted we have to program,” Playter says.

TARDEC has tasked the company to work on a product called Big Dog Mule, which is programmed to follow a soldier carrying a heavy load. The ultimate goal is to have the robot follow a soldier up a craggy mountain path on its own four legs. “The level of performance you need (from legged robots) doesn’t exist yet,” Playter says.

Integrating humans and machines is a key priority. The Army is not interested in something that requires too much specialized training. “Where we want to go is to make the robot see a platoon member,” says Jeff Jaczkowski, an electrical engineer for the TARDEC.

Towards that end, DARPA is looking at smaller mechanical animals for military purposes. A Chihuahua-sized machine, dubbed Little Dog, is the subject of a solicitation released in late March.

Crucial to the idea behind Little Dog is the ability to navigate really rough terrain “There’s no way to tele-operate one of these things,” says Larry Jackel of DARPA’s robotic initiatives. The robots will have to make those decisions themselves. The project aims “to create a library of behaviors,” he says.

Right now, Little Dog can’t surmount a ream of paper laid flat, Jackel says. Computer models of software designs take minutes for the simulated four-legged robot to make up its mind and successfully climb a small, sharp-edged obstacle.

The military researchers are trying to come up with capabilities before they are asked. They know that when more complex, “thinking” robots are fielded, troops on the frontline and their commanders will not want to be limited in urban settings and rough terrain. Likewise, they are trying to make the sensors efficient, rugged and small.

“If you have sensors with temperature ranges that we see in today’s conflicts, you can’t play,” Shoemaker says. “Everyone is looking for the same real estate on these vehicles,” he says. “Being smaller is an asset.”

Brewer says the tempo of operations has increased the pace and interest in developing robotic behavior, especially in the situations in which robots must be able to function. “We go through scenarios with them, always changing things,” Brewer says. “If there’s a new box near the road, an IED or something, we want them to notice that.”

To the soldiers tasked with teaching the robots, the future means a safer way for them to do their business. Asked if his job as a scout would one day be taken over by robots, Brewer was unambiguous: “It’s coming, no doubt.”

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