Tuesday, August 16, 2011

Lasers to Spot Bombs, IEDs

Imagine a checkpoint where Soldiers don't have to walk up to a vehicle that's been rigged to explode, but instead, they can detect the explosives at safe, standoff distances. That's the kind of technology the Army Research Laboratory, or ARL, is investing in as part of a research effort now shared with the Leonard Wood Institute in Missouri.

That technology is laser spectroscopy, which can be used for standoff explosive detection, is based on ARL's advanced research in laser-induced breakdown spectroscopy. It is 1980s technology that today can detect explosive threats in real time, sometimes processing agent analysis in as little as one-second. The Leonard Wood Institute work involved advancing current technology to detect such threats, including home-made explosives, beyond 20 meters.

The Leonard Wood Institute, or LWI, is a non-profit organization located at Fort Leonard Wood, Mo., that was created to connect regional businesses and university expertise to Army training and technology needs. Its formal Cooperative Agreement with ARL's Human Research and Engineering Directorate allows LWI to initiate, fund, manage and participate in applied research, and build capacity to support Army innovation.

The laser spectroscopy testing launched at Fort Leonard Wood looks to be a promising way to keep Soldiers out of harm's way, experts say. The newest system based on that technology, the Checkpoint Explosives Detection System, uses a multi-modal approach to detect harmful materials. The system combines ARL's laser induced breakdown spectroscopy, the ultraviolet Raman spectroscopy and Townsend effect plasma spectroscopy.

This combination could be vital in the counter-improvised explosive device, or IED, effort and thereby, saving lives in current and future counter-IED operations, said Alan Davison, chief of the Maneuver and Mobility Branch with ARL's Human Research and Engineering Directorate at the Fort Leonard Wood Institute.

U.S. and coalition forces in Afghanistan and Iraq currently have no effective means to detect trace elements of explosives from a distance that make up the enemies' strategic weapon of choice, IEDs, which are the primary cause of death and injury to American Soldiers.

Improving upon systems like this, while also using robots, keeps Soldiers out of harm's way.

"One of the biggest challenges that Soldiers have when operating robots is that the two-dimension computer displays they use provide very limited depth perception," Davison said. "Two-dimension displays do not provide the kind of depth perception needed to perform many military tasks."

For example, if a Soldier is searching through a pile of roadside garbage for an IED using a robot, it is much more difficult to manipulate objects using the robotic arm through a 2-D computer screen because the Soldier cannot perceive how deep that robot should truly dig in the garbage.

Three-dimensional visualization, however, greatly improves the Soldier's ability to mentally place an object in the spatial world. ARL researchers believe that by combining the benefits of 3-D or stereo vision with tactile feedback enhanced manipulation, Soldiers will be much better enabled to locate and manipulate objects associated with IEDs. This improved capability should also lead to less time in hazardous zones while working with IEDs or their components.

"Up until recently, the robotic work has focused on improving the stereo-vision. That clearly has helped the Soldier see what he is trying to accomplish by manipulating the arm. But as the stereo-vision continued to improve, it became more obvious that the robotic work was still not nearly as good as human performance," said Davison.

"For example, reaching out to grab a bottle was difficult and not so much because the visual was not good but that the manipulator arm was hard to control."

He said an ARL experiment, planned for September 2011, will combine a tactile feedback (haptic) manipulator arm that operates much more like the human hand with some force feedback through the manipulator to the controller in the Soldier's hand, with a 3-D stereo vision system.

"While robotics are probably a long way from approaching human performance in many tasks, if we can close this gap, we can improve what a Soldier can do with a robot and reduce the time in the most dangerous conditions."

Soldiers in combat today often get up close and personal to dangerous objects, and use hand-held devices with sensors to detect all metallic and nonmetallic antitank and antipersonnel mines. That technology, the AN/PSS-14, combines ground penetrating radar and highly sensitive metal detector technology using advanced data fusion algorithms.

This combination allows the system to detect anti-personnel and anti-tank mines but operators of this eight-pound hand-held device need refresher training about every 60 days or less on well-prepared training terrains. Researchers from ARL, LWI, industry and academia have developed a device that can effectively bring refresher training to operators in a small, indoor environment, which is a quick-fix to locations where the more traditional training sites are not always available, and are expensive to set up.

The team developed two landmine detection training simulators -- including all hardware and software -- that are similar to the AN/PSS-14 landmine detector. The system uses two cameras, which wirelessly transmit information to a laptop via Bluetooth technology.

The training device, they say, offers an efficient, low-cost way to provide realistic landmine detection training for Soldiers, allowing the trainer to give valuable, real-time feedback to equipment operators. Training with this new device can be conducted inside, in only a small area. While it is not designed or expected to completely replace the traditional training on outdoor lanes, it can provide an opportunity for badly needed refresher training.