Archive for the 'Technology' Category

Mil Tech — Autonomous Underwater Vehicle Swims Like a Fish

Jul 09 2015

Published by under Technology

The manner in which fish’s fins allow it to swim is the inspiration for the design of a unique underwater propulsion system being developed by the U.S. Naval Research Laboratory (NRL) in Arlington, Va.

WANDA, the Wrasse-inspired Agile Near-shore Deformable-Fin Automation, is a man-portable autonomous underwater vehicle (AUV) that uses two pairs of fish-like fins that allow it to conduct missions in littoral zones where low speed and high maneuverability are prized capabilities.

Jason Geder, aerospace engineer at the NRL’s Laboratories for Computational Physics and Fluid Dynamics, says WANDA was inspired by the pectoral fins of the reef fish, bird wrasse, and allowed NRL researchers to develop a vehicle with an actively controlled curvature robotic fin that provides scaled down AUVs with a low speed propulsion system.

“The actively controlled curvature fins allow the vehicle to maneuver more precisely than a propeller driven vehicle,” Geder points out. “Propeller systems have issues with dead zones and overshoot that WANDA does not.”

WANDA has two pairs of pectoral fins, two forward and two aft on the vehicle. Geder says WANDA’s uniqueness lies in the fact it actively controls the curvature of its fins by actuating individual rib bars within the fins, which allows it to swim through the water by an oscillating motion.

The current version of WANDA is 3-1/2 feet long with a nearly elliptical cross section that’s approximately 14 inches in width at its widest point and less than 10 inches at its highest point.

“The dry weight, depending on its payload, is approximately 25 pounds and can be picked up by a single person,” Geder says.

WANDA carries sensors on board for navigation, operation and maneuvering, relying on an inertial navigation system, angular rate gyros, accelerometers for measuring heading and the angle of the vehicle, a pressure sensor for measuring depth, and a GPS for fixing its location if it comes to the surface, Geder says.

Geder says NRL researchers have developed near-field pressure sensors that allow WANDA to detect current flows and static objects in the near field. “It’s like the lateral line sensors fish use to detect objects on their side and front,” he says. “The fish use a system of hair-like pressure sensing elements that allow them to sense changes in the flow field around their body. We are testing those kinds of sensors with WANDA for their navigational capabilities.”

WANDA’s modular construction allows it to be integrated for a number of different mission-specific payloads, Geder points out. “Besides the near-field sensors, we also are developing chemical sensors for detecting underwater chemical signatures in the environment, where they would detect a particular element and then use that information to navigate upstream to where it’s coming from,” he says. “If WANDA is close to the surface, it can communicate that information in real time by wireless data transfer and also store the data on board for later downloading.”

Geder says NRL has programmed a number of different maneuvers and missions into WANDA.

“These are closed loop maneuvers, where, for example, the vehicle would dive to a certain depth, do a certain pattern like a box or a lawnmower pattern, and then return to the surface to transfer the data,” Geder says. “It also has the capability for manual operation for testing purposes, where a user controls the vehicle.”

Geder says the next step in the development of WANDA is improving the vehicle’s robustness for field trials that will be conducted this summer in the Washington, D.C. area with a number of NRL collaborators.

About the author: Alan M. Petrillo is a Tucson, Ariz., journalist who writes for national and regional magazines and newspapers. He’s the author of several books on historical military firearms and two historical mysteries, Full Moon, and his latest novel, Asylum Lane, all available at www.amazon.com.

No responses yet

Mil Tech — Naval Research Laboratory Produces Transparent Armor-like Material

Jun 01 2015

Published by under Technology

The Naval Research Laboratory has made a transparent ceramic that can be used to armor lenses and face shields and in other applications.

The U.S. Naval Research Laboratory (NRL) has invented a special ceramic that looks like glass but is much harder, is tough like armor, and can be used on unmanned aerial vehicles, lenses, face shields and electronics protection.

Jas Sanghera, Ph.D, branch head of Optical Materials and Devices at the NRL, says  the material, spinel, goes back to the 1960s when researchers attempted to make it synthetically.

“The material is found in nature as a mineral in small sizes, but for practical applications, one needs material larger than a centimeter, which is not found in nature,” Sanghera says. “Researchers tried to pack spinel powder into a denser material through a pressing process known as sintering, and if one does it right, the process gets rid of the empty space, the porosity, and the material becomes clear. We were able to do that.”

Sanghera says that NRL scientists were able to use a solid state process to heat the spinel to 1,500 degrees Centigrade, which is well below its melting point of 2,000 degrees Centigrade.

“We use a hot press that applies pressure to the material like a piston would to plungers inside a tube,” he points out. “We elevate the temperature, evacuate the air and the material is allowed to densify. The trick is to get rid of all the entrapped air in the material, and if you do that right, the result is a clear looking material.”

The resulting product is thinner than glass but much stronger, Sanghera notes. The NRL has produced spinel that is up to 11/2-inches thick, but is able to make thinner sheets of the material because most applications require a covering less than one inch thick, typically around a half-inch or less.

“This really is a transparent armor-like material,” Sanghera observes. “We have demonstrated the feasibility and transitioned this technology to industry to enable fabrication of larger finished products in the 25-inch square size.”

Sanghera says the transparent armor likely could be used for platform protection purposes.

“When you have cameras that operate in visible and infrared, it’s nice to have a rugged window in front of them,” he says. “Protecting cameras and sensors in military hardware is an important application. Wherever you see glass, polycarbonate or plastic, those can be areas for replacement by this material.”

Sanghera notes  the strength of the transparent armor ranges by the size and shape of the finished material but that typically it is more than three-times stronger than glass of the same size.

“One of the areas of interest is replacing ballistic glass,” he says. “That’s a laminate of glass and plastic layers. The glass part of ballistic glass could be replaced with spinel, which would reduce the weight and thickness of the armor but give a greater strength.”

About the author: Alan M. Petrillo is a Tucson, Ariz., journalist who writes for national and regional magazines and newspapers. He’s the author of the historical mystery, Full Moon; the nonfiction work, Ice Hockey in the Desert; and his newest historical mystery, Asylum Lane, all available at www.amazon.com.

No responses yet

Mil Tech — Robotic Systems for Soldier Teammates

May 07 2015

Published by under Technology

The U.S. Army Research Laboratory (ARL) is working on creating robotic unmanned aerial vehicle (UAV) systems that can act as teammates for dismounted soldiers in the field, where the units sense their environment and navigate on their own to perform a mission designated by the soldier.

Brett Piekarski, Ph.D, program director for the ARL’s Micro Autonomous Systems Technology Collaborative Technology Alliance, says soldiers have used robotics — such as ThrowBots, Recon Scouts, Puma, and Raven systems — in theater recently.

“Those units were in response to rapid fielding requests, but they have little to no autonomy, although they provide a lot of capability for soldiers to have situational awareness when they are used to look in a building, over a hill, or in a culvert,” Piekarski says. “But to use them, the soldier has to put his weapon down and look at a control screen and other soldiers have to be there to protect him. We want to task a robotic platform that acts as a teammate to the soldier where it would have the intelligence to execute a command without the hands-on guidance of the soldier.”

Piekarski notes ARL’s collaborative technology alliances are government, industry, and academia research partnerships focused on Army transformation technologies. He says a micro-mechanics center researches how to scale robotics down and understand the aerodynamics of small propulsion systems, while a micro-electronics center is looking at scaling down sensors and processors to allow more efficient payloads and power use. A center for autonomy is working on systems that sense the environment and then move rapidly through it, and another center is working on the human-robot teamwork relationship.

One of ARL’s goals is to produce a UAV that would fit in the palm of a soldier’s hand or in his pants cargo pocket.

 “We have systems one kilogram in size that can fly autonomously in a building and map it,” Piekarski says. “We’re seeking to scale that weight down to 20 grams, but there’s also the question of robustness of the unit because the Army needs it to work in every environment.”

 A small scale UAV recently was tested at Maneuver Center of Excellence at Fort Benning, Ga., to demonstrate how the UAV can team with a soldier. Brendan Byrne, an ARL engineer, says the test involved a 2-1/2-foot wide quad-rotor UAV.

“The UAV performed a successful mapping demo,” Byrne says. “It took off, approached the building, flew in and out of windows and doorways, and operated in hallways and corridors cluttered with bookcases and other obstacles. It performed very well inside the building.”

However, when the UAV moved back to an outdoor environment, it didn’t perform as well, Byrne says, because environmental factors such as bright light and open land came into play. “The human-robotic teaming worked and showed these systems are very capable,” he notes, “but to have the ability to move from indoors to outdoors, from low lighting to bright lighting, in both low and high wind speeds, they still are not capable of dealing with all of those things.”

Byrne adds the test UAV didn’t have the sensors on board that could see long range, which was part of the reason why it didn’t work well in the very bright and shadowing exercise.

However, Piekarski is confident that given time, the ARL and research centers will solve the issues of size, efficiency and autonomy, allowing small handheld robotics to function autonomously and carry out the missions assigned by soldiers.

About the author: Alan M. Petrillo is a Tucson, Ariz., journalist who writes for national and regional magazines and newspapers. He’s the author of the historical mystery, Full Moon; the nonfiction work, Ice Hockey in the Desert; and his newest historical mystery, Asylum Lane, all available at www.amazon.com.

No responses yet

TBI Implant Coming

Apr 23 2015

In the past seven years alone, more than 270,000 servicemembers have been affected by traumatic brain injuries (TBIs), and many suffer long-term effects of this unpredictable medical issue. Researchers at several U.S. universities might soon have a novel answer for these servicemembers. The Defense Advanced Research Projects Agency (DARPA) recently awarded $40 million to the University of Pennsylvania; the University of California, Los Angeles; and the Lawrence Livermore National Laboratory for a Restoring Active Memory project to design and test a “neuroprosthesis” — a fully implantable wireless brain chip to bridge broken neural pathways. The chip will allow patients to access old memories while encoding new ones.

The goal, says Dr. Justin Sanchez, a biomedical engineer and program manager at DARPA, is to “demonstrate in patients that this integrated device can effectively restore memory function in a human after having been implanted for at least 14 days.”

A project of this difficulty is no easy feat. First, scientists must understand exactly how the brain encodes memories such as events, times, and places. Then they must determine how to help the brain reestablish memories. Finally, they’ll develop an implant that accurately delivers targeted neural stimulation.

Does this sound like science fiction? Researchers don’t think so. DARPA aims to have a prototype within four years. “In the end,” says Sanchez, “we hope to have accelerated research that can minimize the long-term impacts of traumatic brain injuries, helping servicemembers and others overcome memory deficits.”

— Deborah Huso

No responses yet

Mil Tech — U.S. Army Acquires More Gray Eagle UAVs

Apr 06 2015

Published by under Technology

The U.S. Army will be fielding more Gray Eagle unmanned aerial vehicles (UAVs) for use at the division and corps level once the units roll off the line at General Atomics Aeronautical Systems. The Army recently awarded the company a $133 million contract for 19 Gray Eagles that’s a second purchase on a full-rate production contract.

Courtesy of General Atomics Aeronautical Systems

Courtesy of General Atomics Aeronautical Systems

Gray Eagle is a long-endurance UAV designed for reconnaissance, surveillance, and target acquisition (RSTA); communication relay; and attack capabilities. The 27-1/2-foot long aircraft has a 56-foot wingspan, a maximum altitude of 29,000 feet, and a 3,600-pound gross takeoff weight.

“Doing surveillance, target acquisition, and reconnaissance are Gray Eagle’s main focuses,” says Mike Cardenas, deputy director for the Army Programs Office at General Atomics Aeronautical Systems. “It also has two radios on-board for the purpose of acting as a communications relay to talk with soldiers in the field in real time. In addition, Gray Eagle has four hard points, two on the outside of the wings for 250-pound intel-based payloads and two on the inside part of the wings that can carry 500-pound Hellfire missiles.”

When used in a RTSA configuration, Gray Eagle’s time on station for a location 300 kilometers from its launch point is about 20 hours, Cardenas says.

“If it’s loaded up with Hellfires and other payloads, at 300 klicks it is closer to 13 to 15 hours on station at 10,000 feet,” he observes.

Gray Eagle comes with two line-of-sight antennas, but the aircraft is being supplied to the Army with a satellite antenna that can be mounted to give the aircraft over-the-horizon capability. Gray Eagle also has a fully automated takeoff and landing system.

Cardenas points out that Gray Eagle is meant to be more of a tactical asset for division commanders, but also can be used as a strategic asset.

The Army’s Gray Eagle can be launched, controlled, and recovered at the location where’s it’s operational, Cardenas notes, compared with a U.S. Air Force UAV that might be launched and then have control of the unit given over to someone flying the aircraft via SATCOM (satellite communications).

“A unique element to the Gray Eagle is that it has manned-unmanned teaming, which is used between UAVs and Apache helicopters,” Cardenas says. “Once the Gray Eagle is up, an Apache can take control of the aircraft [and] its payload and Hellfire missiles in order to work together to target a certain location.”

Cardenas says manned-unmanned teaming was part of the operational testing criteria General Atomics Aeronautical Systems carried out in the summer of 2012.

“Shots were fired in teaming with an Apache during the testing,” he notes, “and we had very good success with it.”

Cardenas points out that for all the unmanned aircraft systems that General Atomics Aeronautical Systems makes, manned-unmanned teaming is unique to the Gray Eagle.

“Thus far we have not incorporated it into other assets,” he says, “although it could be done, depending on the system and the customer’s needs.”

Deliveries on the second Gray Eagle purchase contract will be made through September 2017.

About the author: Alan M. Petrillo is a Tucson, Ariz., journalist who writes for national and regional magazines and newspapers. He’s the author of the historical mystery, Full Moon; the nonfiction work, Ice Hockey in the Desert; and his newest historical mystery, Asylum Lane, all available at www.amazon.com.

No responses yet

« Prev - Next »