Thursday, October 23, 2014

Groping in the Dark - Unmanned Underwater Navigation

One of the more pressing technical challenges with today's unmanned underwater vehicles is maintaining an accurate navigational position.  Because GPS signals will not penetrate the water's surface, UUVs typically rely on inertial navigation systems and periodic trips to the surface to gain an accurate satellite fix.
Aquanauts with REMUS AUV - NPS Photograph
Bathymetric navigation, or finding one's ways through the contours of the sea floor, has been a tool used by mariners - both surface and subsurface - since the advent of sonar.  But accuracy was hampered due to inaccurate underwater charts and the processing limitations.

Advances in sensors and computing may change these dynamics as explored in Ensign Jacob T. Juriga's recent Naval Postgraduate School Thesis. Juriga's research
focused on terrain aided navigation (TAN) through a series of autonomous vehicle trials near the Aquarius Underwater Research Station located in Islamorada, Florida.  There, using two REMUS 100 AUVs and a SeaBotix vLBV300 Tethered, Hovering AUV (THAUS) contributed by the Naval Postgraduate School Center for Autonomous Vehicle Research, more than 3,046 sonar images were collected with a BlueView MBE 2250 micro-bathymetry sensor.  Then, the vehicles attempted to navigate using the previously created underwater map. The best run achieved a locational difference of only 2.846 meters from a GPS-aided fix.

Ensign Juriga's work isn't the only Navy effort to improve UUV positioning using TAN. But his thesis also emphasized the importance of autonomy, which "enables the vehicle, through exteroceptive sensing, to make intelligent navigational decisions such as obstacle avoidance and navigation in cluttered, dynamic environments."  

Thursday, October 9, 2014

The Navy's Swarming Robot Boats: Sorting Through the Hype

By now, most readers are familiar with the U.S. Navy's new swarming drone experiment using the CARACaS (Control Architecture for Robotic Agent Command and Sensing)  system for automating small surface craft. The hype surrounding this development is significant, and some of it is rightfully deserved. Automated boats will find a place in future naval operations, but their capabilities and limitations must be more fully understood before that happens. 

August 2014 - A swarm of CARACaS equipped patrol boats on the James River - U.S. Navy image.
The primary benefits of autonomous unmanned vessels are longer endurance than manned patrol boats, and of course, a reduction in risk to human sailors.  Naval budgeteers consistently lament the cost of personnel, so ostensibly, automated boats will be less expensive than training and maintaining human crews.  On the other hand, the Navy's force protection boat crews, most of them resident in the Naval Expeditionary Combat Command are a trivial component of the overall budget, and many of them are part time reservists, which cost even less than their active duty counter-parts.

Perhaps the biggest advantage is that CARACaS is basically "plug and play" and platform agnostic. That means that the system can be rapidly forward deployed by air in a small package and fitted on whatever patrol boats are available versus having to transport a much heavier dedicated USV via expensive air or sealift. And since it reportedly only cost about $2,000 to outfit a patrol boat with CARACaS, outfitting several existing boats might be orders of magnitude cheaper than dedicated USVs. So creating a small boat swarm could be achieved fairly rapidly and cheaply if one were needed.

Myths & Limitations
The CARACaS boats have so far been employed from inland ports, limiting their utility to the fleet. It would be a non-trivial technical feat to launch such a large and recover a swarm of boats from a navy ship at sea.  Only a handful of ships in the fleet could realistically embark more than a couple of unmanned vessels. The U.S. Navy's cruisers and destroyers usually only carry two rigid hull inflatable boats, which are dedicated for other missions such as boarding operations.  Larger amphibious ships could carry several more boats in their well decks, but then would be unable to embark their usual load of landing craft.  That is not to say that several combatants couldn't launch their boats simultaneously and then the swarm would aggregate, but that is unlikely given how disbursed ships operate these days.  Of course, these autonomous boats could also be launched from a coastal base as they were during the experiment, but that would limit their employment to fairly close to shore.  Moreover, new software algorithms will need to be developed to help these boats safely approach their motherships, launch, and recover in any sort of sea states.

As with any unmanned system, options to fix mechanical malfunctions about CARACaS-equipped craft would be significantly limited. Minor engine problems or weapons jams that could be easily corrected by an onboard crewman will likely render an unmanned platform ineffective without some form of redundancy.

This technology is still immature and close-in maritime force protection as demonstrated in the James River involves high speeds and rapid decision making.  The ethical issues concerning lethal automated drones have been covered extensively elsewhere.  But even with experienced human boat operators, making a decision whether or not to engage a suspicious contact vessel is difficult. Generally, when threatened with a suspicious contact, a gradual escalation of force occurs that can take anywhere from a couple of minutes to a handful of seconds.  Warnings, shouldering, non-lethal, and lethal weapons, can be employed in various combinations to deal with a threat. In a fully unmanned or even autonomous system, communications latency, jamming, and operator inattentiveness could all play a role in this system failing to protect its escorted high value asset, or in creating an undesirable escalation of force.

Concerning the CARACaS swarm, Rear Admiral Matthew Klunder, Chief of Naval Research commented that "If [USS] Cole had been supported by autonomous unmanned surface vessels, they could have stopped that attack."  This statement could be theoretically, true, if USS Cole had been capable of carrying and deploying a number of USVs (it couldn't) and if no other counter-measures were available.  These defensive measures could have been as simple as enhanced rules of engagement, better intelligence on the threat at the time in Aden, one or more manned picket boats, or simply avoiding Yemen as a refueling stop all together.  

CARACaS patrol craft escort a simulated "high value" vessel near the Navy's Ghost Fleet - U.S. Navy Photo.
The future addition of “automated target recognition” systems will help the USVs discern the difference between friendly and potentially hostile craft.  Additional automation will also enable CARACaS-equipped boats to follow internationally-recognized rules of the role which will enable them to operate in more congested maritime environments.  This level of autonomy will be necessary before the system can operate in any sort of constrained waters, which is generally where force protection missions occur.

Aside from the force protection mission demonstrated by ONR, automated small boat swarms could support a number of other naval missions.  A better use of this technology than for force protection might be to enable autonomous swarms of mine hunting craft, such as the Mine Hunting Unmanned Surface Vehicle.  Mine hunting and other underwater searches, such as that performed for the missing MH370 jetliner, are more laborious and painstaking than coastal patrol and interdiction.  This sort of technology could enable them to be completed more efficiently and rapidly.  

Offensive unmanned boat swarms could harass, impede, and attack enemy shipping without risking the lives of friendly sailors.  Depending on the sea state, these swarms could remain dormant for some time in a maritime choke point, then activate as an enemy vessel began to transit through the area. They could also serve as forward observers to target enemy craft for destruction from airpower or ship-launched missiles. 

The collection of intelligence is another mission for which this technology might work well. Semisubmersible or indigenous autonomous craft are low visibility and could be outfitted with sensors and the CARACaS package.   For example, a small unmanned fishing vessel equipped with sensors could probably infiltrate an adversary's port of interest without causing any alarm much easier than a recognizable naval patrol boat.  USVs can even be equipped to carry UAVs to extend their sensor range, which is one of the options under consideration for the Littoral Combat Ship's mine-sweeping CUSV.

Bottom line, CARACaS is a worthwhile research effort, but probably not for the reasons the Navy currently envisions.  The demonstrations thus far have been impressive, but also highly scripted and controlled.  Future tactical employment of automated boat swarms in any meaningful manner is likely at least a decade away.  But the plug-and-play nature of singular CARACaS-fitted boats will probably happen much sooner.

Thursday, October 2, 2014

On Defending Ships With Counter-Measure Drones

Lieutenant Matt Hipple, United States Navy has begun a full court press to use unmanned systems as a form of defense against anti-ship missiles.  Here in Proceedings, he discusses the concept of unmanned aerial vehicles as a decoy to draw fire away from naval vessels.

Matt sees these systems as a viable alternatives for shipboard defense to those currently in use, to include missiles, close-in-weapon gun systems, active electronic jamming, and passive distraction measures such as chaff. Here, he presents his case to Athena East,

When considering the ever-increasing numbers of sea and shore-based anti-ship missiles versus a smaller inventory of expensive defensive Standard missiles, the concept sounds reasonable.  The idea of aircraft as defensive ship decoys certainly isn't new.  In the Falklands conflict, Prince Andrew flew his helicopter in this manner to defend against Argentina's Exocet missiles.  "The helicopter is supposed to hover near the rear of the aircraft carrier, presenting a large target to attract the missiles," he said in a 1982 AP interview.  Drones would present a number of benefits over manned aircraft for this purpose, starting with the fact that an aircrew would not be placed at risk.  Drones provide considerable endurance advantages over manned helicopters, with some models able to fly up to 24 hours at a time. Additionally, smaller, more affordable UAVs can be deployed in numbers, protecting a ship along multiple threat axes. They could carry their own passive counter-measures, such as chaff or obscurants, while emitting electromagnetic radiation of various frequencies to draw in radar-seeking missiles.  They might even be equipped with compact high power radio frequency payloads to fry an incoming missile's electronics.

Across the history of warfare, improvements in offensive and defensive technology have driven innovation and cost-benefit trade-offs.  Counter-measures beget countermeasures, so inevitably the effectiveness of these defensive drones would be eclipsed by new offensive technology.  But in the interim, the U.S. Navy might want to invest some time, money, and energy in small scale concept validation experimenting with existing relatively affordable VTOL UAVs such as the S-100 or Skeldar.

Tuesday, August 26, 2014

NGO Uses Drones for Maritime Rescue

An S-100 UAV Approaches Motor Vessel Phoenix (Image courtesy MOAS)
We've written about the use unmanned air vehicles by maritime conservation organizations.  We've also highlighted the use of drones by European navies to support naval forces in interdicting the stream of refugees moving across the Mediterranean from North Africa.  In a predictable evolution of this trend, the non-profit Migrant Offshore Aid Station (MOAS) group has flown its first unmanned aircraft maritime patrols 30 nautical miles Southeast of Lampedusa, Italy from the motor vessel Phoenix. The two S-100 UAVs embarked on Phoenix and operated by Schiebel technicians will be able to locate and assess migrants in distress. According to MOAS co-founder Chris Catrambone, the drones will act as a "force multiplier" during their 21 day mission to assist navies in rescuing vessels along the most traversed migrant route.

Sunday, July 6, 2014

Paul Scharre on Robot Swarms

On June 11, at the eighth annual Center for New American Security’s National Security Conference, Paul Scharre, Fellow and Project Director for the 20YY Warfare Initiative discussed the future of robotics in warfare to include the use of unmanned swarms, which have been discussed extensively here.  The video (below) is thought-provoking, and worth watching in its entirety, but we've provided the highlights, especially as they relate to naval systems.

He describes several naval scenarios, including the use of unmanned surface vehicles to disrupt small boat swarm attacks on larger combatants and UAV counter-swarms. He also proposes that unmanned missile barges could work in tandem with the U.S. Navy's fleet of guided missile destroyers are limited in magazine capacity for missile defense.

In the undersea realm, Scharre alludes to DARPA's Hydra project, in which unmanned vehicles would sit dormant on the sea floor until required to awaken for their missions.  Also of note, is the discussion on the Army's multi-aircraft control, increased automation, and that technology's potential to enable drone swarms.

During the Q&A, he addresses one of the primary criticisms of unmanned aircraft skeptics; that is, the requirement for constant bandwidth, which could become a liability in an electromagnetically-contested environment.  In addition to increased autonomy mitigating that issue, Scharre notes that only a small percentage of bandwidth in use today is devoted to vehicle control; most is dedicated to transmitting real-time full motion video from the UAV's sensors.  In some scenarios, such as hunting for military targets with specific signatures, that sort of bandwidth would be unnecessary.

Perhaps most interesting was his reference to the forthcoming study on swarming that the 20YY Warfare Initiative will produce later this year.

Thursday, June 5, 2014

Autonomous Submarine Drones: Cheap, Endless Patrolling

The US Navy recently announced that it will make more use of submarine drones, contracting with marine technology developer Teledyne Benthos to re-purpose the Slocum Glider as an instrument used for military activity. The contract is worth $203.7M.
If you haven’t heard of it yet, here is what the Slocum Glider is: a 5 foot-long autonomous underwater vehicle capable of moving to specific locations and descending to depths of 4,000 feet. It is driven by variable buoyancy, and it can move both horizontally and vertically.
The Slocum Glider can be programmed to patrol for weeks at a time, collecting data on its environment, surfacing to transmit to shore while downloading new instructions at regular intervals.
Compared to traditional methods, the drones have a relative small cost: the need for personnel and infrastructure is reduced to its minimum and the vehicle is able to work around the clock and around the calendar. It works very well: in November 2012, an autonomous glider set a Guinness World Record by traveling over 14,000 kilometers on an autonomous journey of just over one year duration!
Many Navies and ocean research organizations already use a wide variety of gliders, which cost around $100,000. But the US Navy now plans to increase the number of those drones from 65 to 150 by 2015. In its 2015 budget request, the US Defense Advanced Research Projects Agency even claimed for $19 million to develop drones “that can provide non-lethal effects or situational awareness over large maritime areas.” This represents a spending increase of nearly 60 percent over 2014!
The good news for us is that these submarine drones, unlike the majority of airborne drones, won’t use environmentally unfriendly fuel. Instead, the glider is propelled by the thermocline, which is thermal energy found between the upper and lower mixed layers of sea water. The upper surface has a near atmospheric temperature while the deep water ocean has a temperature situated between 2 and 4 °C.
Those new submarine drones can be used to predict the weather by collecting an enormous amount of data at various spots in the ocean. In 2011, a US Government Accountability Office report warned that without improvements to their earth-monitoring capabilities, the USA would “not be able to provide key environmental data that are important for sustaining climate and space weather measurements”; data for warnings of extreme events such as hurricanes, storm surges, and floods would then be less accurate and timely. This led the US Navy to make a deal to share the Navy Ocean Forecast System software with the National Ocean and Atmospheric Administration.
But that’s not all: another autonomous submarine drone, the Bluefin-21, created by the American company Bluefin Robotics, has scanned just over 300 square kilometers of Indian Ocean seabed searching for the wreckage of the lost Malaysian plane, whichdisappeared from radar screens on 8th March. The drone was launched from the Australian Defence Vessel Ocean Shield.
Bluefin-21 is an autonomous underwater vehicle, 4.93 meters long and 53 centimeters in diameter, specially designed for detection, recognition and statements in the seabed.It is capable of carrying various sensors and payloads. This technology, called side-scan sonar, builds a picture of the seabed at a 4500 meters depth.
This drone also has a significant autonomy, 25 hours at 3 knots average, which allows it to achieve extended underwater missions.It weighs 750pounds, which makes it easily transportable by a wide range of boats.
From all this, it is clear that submarine drones will become an important part of the navies’ equipment!
By Alix Willimez. Reprinted with permission from the Center for International Maritime Security.

Wednesday, May 7, 2014

The Most Realistic Fish-bot You've Ever Seen - and What it Could Mean for Naval Warfare

Bio-inspired maritime robotics is an emerging field gaining significant traction. Two examples the U.S. Navy has funded include Boston Engineering's Bioswimmer, and the odd robotic jellyfish, Cyro.  Both of these projects look clumsy compared to a robotic fish recently developed by a consortium of Polish researchers from the Technical University of Krakow, the marine technology firm  FORKOS, and the Polish Naval Academy.  The group's CyberRyba ("Cyber-fish") autonomous underwater vehicle can move along a preset route, but will eventually be able to autonomously avoid obstacles and log data from a sonar or video camera. The carp-like CyberRyba's uncanny realistic movement is aided by an articulating body and tail as well as independently moving pectoral fins allowing it to hover in place.

The ultimate goal of the research is to support the European Defence Agency's "Swarm of Biomimetic Underwater Vehicles for Underwater ISR" (SABUVIS) program beginning in 2015.  The EDA currently runs a €53.7 million Unmanned Maritime Systems (UMS) program, in which 11 countries are focused on improving mine-counter measures and related naval technologies.

How might such swarm of life-like robo-fishes be employed tactically by a Navy? There are several possible future scenarios, with the most obvious case being environmental characterization. Hydrography, the study of the physical features of the ocean, and oceanography are critical for nearly all naval operations. An understanding of a body of water's temperature, salinity, bottom composition, acoustic properties, etc. supports amphibious landings, anti-submarine warfare, and mine counter-measures.  Autonomous underwater vehicles are rapidly becoming the go-to technology for these operations, and a swarm of AUVs communicating with each other and perhaps a mothership or base station would complete survey missions more rapidly than individual drones or divers. To conduct intelligence, surveillance, and reconnaissance (ISR), schools of cyber-fishes might emplace, monitor, and relay data from unattended underwater sensors or be the sensors themselves.  In support of future anti-submarine warfare, AUVs positioned at various places in the water column could each carry a single hydrophone, enabling them to triangulate the acoustic signals from an enemy submarine.

See these posts for more information on how drone swarms will impact future naval warfare.