Long Distance Tele-Operation system for remote control of unmanned ground vehicles
By Darren Quick
August 3, 2011
The U.S. military is currently able to operate unmanned aircraft systems (UAS) in far away countries from the U.S., while ground robotic systems such as the TALON can be remotely operated at distances of up to 1,000 m (3,280 ft). Now U.S. Army engineers have provided unmanned ground vehicles (UGVs) with the long distance tele-operation capabilities of a UAS to allow them to be controlled from anywhere in the world and keep soldiers even further out of harm's way.
The technology developed by the U.S. Army Tank Research, Development and Engineering Command's, (TARDEC), Tank and Automotive Research Center currently allows UGVs to be operated via the Internet using a cellular data signal. Operators are able to log into the Long Distance Tele-Operation, (LDTO), system via a secure Web portal. Once connected, the operator selects a platform from a drop-down menu and is directed to a user interface screen that includes a variety of commands and a video link with the platform.
"While UAS are flying in theater, they're being controlled from here," said Ground Vehicle Robotics (GVR) System Integration Laboratory Electrical Engineer Ty Valascho. "Our task within GVR was to see if we could get that capability working and be able to drive it using all in-house assets."
By working with the original equipment manufacturers to get interface information about the various fielded robotic platforms the team was able to integrate the LDTO capability onto a number of UGVs. So far they have demonstrated the system with the TALON, PackBot and Omni-Directional Inspection System platforms.
"One of the constraints we put on ourselves was that we wanted to use whatever systems they were using in theater because it would make the transition to the field easier," Valascho stated. "Because these were largely commercial-off-the-shelf robots that had been rapidly fielded, the government had no technical data packages on the platforms. So that was a big challenge. We had to work with that supplier to get some information. They were very helpful, but it took a few months to get that information."
While LDTO has been successfully used to control UAS's in theater, adapting the system to ground vehicles posed problems that aerial vehicles operating in tightly controlled airspace don't face.
"UGVs have mobility challenges going down slopes, moving up slopes and watching out for obstacles on the ground that they can't overcome or that could overturn them. Those are all things that a UGV operator has to be aware of that someone driving an air asset doesn't," said Valascho.
And while video cameras allow operators to see oncoming hazards, the use of unpredictable Internet connections and data feeds poses significant challenges.
"If the robot's moving at full speed and you're trying to negotiate around something, even a half-second delay can make a huge difference," Valascho noted. "Latency is a problem, and the fact that we're going over the Internet adds another challenge, because it's not constant latency. This is a variable latency, so sometimes the delays are very great and sometimes there's very little delay. We're trying different techniques to minimize the effect on the user."
Currently, a common basic interface is used to control all platforms but the team is developing a user interface that is easy to use, yet still allows for the full range of platform capabilities. The engineers have got the system working and believe they have got the latency down as far as they can by slightly redesigning the system. Valascho believes the system could serve as a foundation for future fielded operations.
"If this were to be a fielded solution, there would have to be a lot of redesign because we would use military satellites and would be doing things a lot differently. Right now, we're just showing what's possible, but there are big parts of the system that could be reused if this were fielded," says Valascho. "Driving a robot professionally is a specialized skill; it isn't something that just anybody can do. Our warfighters are very valuable people, so we try to reduce the amount that they're put into harm's way. I think this would be a very big benefit for the Army in terms of reducing risks to these valuable assets."
Source: U.S. Army