Since the creation of the main battle tank during World War I, there has been a constant arms race between the development of anti-armor weapons and vehicle protection systems, however “Weapons’ ability to penetrate armor, however, has advanced faster than armor’s ability to withstand penetration”.
The traditional protection technique depends on the amount of armor, has reached a practical limit for today’s threat environments, as main battle tanks and infantry fighting vehicles have reached weights approaching 70 tons. The trend of increasingly heavy less mobile and more expensive combat platforms has limited Soldiers’ ability to rapidly deploy and maneuver in theater and accomplish their missions in varied and evolving threat environments. Moreover, larger vehicles are limited to roads and bridges they are able to travel on, require more logistical support and are more expensive to design, develop, field and replace.
DARPA launched Ground X-Vehicle Technologies (GXV-T) program aims to improve mobility, survivability, safety, and effectiveness of future combat vehicles without piling on armor. Several Phase 2 contract awardees recently demonstrated advances on a variety of potentially groundbreaking technologies to meet the program’s goals.
“We’re looking at how to enhance survivability by buttoning up the cockpit and augmenting the crew through driver-assistance aids,” said Maj. Amber Walker, the program manager for GXV-T in DARPA’s Tactical Technology Office. “For mobility, we’ve taken a radically different approach by avoiding armor and developing options to move quickly and be agile over all terrain.”
The Ground X-Vehicle Technologies (GXV-T) Program is largely complete, and it’s archived on DARPA’s website. Most of the tech has proven itself in the lab and testing, but now some will—and some won’t—get deployed to units over the next few years.
DARPA’s Ground XVehicle Technology (GXV-T) program
DARPA has launched Ground XVehicle Technology (GXV-T) program seeks to develop revolutionary technologies to enable a layered survivability approach, which is not entirely armor-based, against multiple classes of threats to armored vehicles. A layered approach should consist of technologies that: reduce vehicle detection, reduce the likelihood of a vehicle being engaged, reduce the chances of both guided and unguided rounds hitting the vehicle and reduce the effectiveness of modern threats to armored vehicles.
“We’re exploring a variety of potentially groundbreaking technologies, all of which are designed to improve vehicle mobility, vehicle survivability and crew safety and performance without piling on armor,” said Maj. Christopher Orlowski, DARPA program manager. “DARPA’s performers for GXV-T are helping defy the ‘more armor equals better protection’ axiom that has constrained armored ground vehicle design for the past 100 years, and are paving the way toward innovative, disruptive vehicles for the 21st Century and beyond.”
DARPA’s technical goals for improvement over current vehicles are reducing vehicle size and weight by 50 percent to greatly enhance strategic mobility, reducing crewman needs by 50 percent, Increase vehicle speed by 100 percent, accesses 95 percent of terrain and reduce signatures areas including Visual, Thermal/Infrared, Acoustic, Electro-magnetic, Dust and Ground tracks/”footprints” that would be detectable by enemy.
GXV-T is pursuing research in the following four technical areas:
- Radically Enhanced Mobility— Ability to traverse diverse off-road terrain, including slopes, various elevations, and a range of surfaces and gradients; advanced suspensions and redefined track or wheel configurations; extreme speed; rapid omnidirectional movement changes in three dimensions. Capabilities of interest include revolutionary wheel/track and suspension technologies that would enable greater terrain access and faster travel both on- and off-road compared to existing ground vehicles.
- Survivability through Agility—Autonomously avoid incoming threats without harming occupants through technologies that enable, for example, agile motion and active repositioning of armor. Capabilities of interest include vertical and horizontal movement of armor to defeat incoming threats in real time.
- Crew Augmentation—Improved physical and electronically assisted situational awareness for crew and passengers; semi-autonomous driver assistance and automation of key crew functions similar to capabilities found in modern commercial airplane cockpits. Capabilities of interest include high-resolution, 360-degree visualization of data from multiple onboard sensors and technologies to support closed-cockpit vehicle operations.
- Signature Management—Reduction of detectable signatures, including visible, infrared (IR), acoustic and electromagnetic (EM). Capabilities of interest include improved ways to avoid detection and engagement by adversaries.
DARPA has awarded contracts for GXV-T to the following organizations:
- Carnegie Mellon University (Pittsburgh, Pa.)
- Honeywell International Inc. (Phoenix, Ariz.)
- Leidos (San Diego, Calif.)
- Pratt & Miller (New Hudson, Mich.)
- QinetiQ Inc. (QinetiQ UK, Farnborough, United Kingdom)
- Raytheon BBN (Cambridge, Mass.)
- Southwest Research Institute (San Antonio, Tex.)
- SRI International (Menlo Park, Calif.)
Demonstrations, such as one in May at Aberdeen Test Center, have given potential military service transition partners an opportunity to observe technical progress on the GXV-T program, including:
Radically Enhanced Mobility
GXV-T envisions future combat vehicles that could traverse up to 95 percent of off-road terrain, including slopes and various elevations. Capabilities include revolutionary wheel-to-track and suspension technologies that would enable access and faster travel both on- and off-road, compared to existing ground vehicles.
Other tech breakthroughs looking to increase off-road mobility included the Electric In-Hub Motor—which crams an entire electric motor with a three-speed gearbox and cooling into a standard 20-inch rim—and the Reconfigurable Wheel-Track which can roll like a normal tire or turn into a triangular track that works like a mini-tank tread.
Reconfigurable Wheel-Track (RWT)
Ground combat vehicles still use the same track- or wheel-based configuration, with the same pros and cons for each approach. Tracks are more useful for sand and rough terrain, while wheels allow speedy movement over road networks. Wheels permit fast travel on hard surfaces while tracks perform better on soft surfaces.
A team from Carnegie Mellon University National Robotics Engineering Center (CMU NREC) demonstrated shape-shifting wheel-track mechanisms that transition from a round wheel to a triangular track and back again while the vehicle is on the move, for instant improvements to tactical mobility and maneuverability on diverse terrains.
The researches say the transforming wheels work by changing the surface area of the tyre in contact with the ground based on the terrain. When on a smooth surface, it reduces the surface area of the contact patch and thus able to achieve higher speeds. When the terrain changes and becomes unfavorable (off road) the wheel increases the surface area of the contact patch for maximum traction. It then works like a snowshoe and thus the vehicle is able to move over soft grounds (soft soil, ground filled with snow) much more effectively than on a spinning circular wheel.
Vehicles equipped with RWT will be less constrained by terrain and better at maneuvering against opponents. The wheel-tracks could make military vehicles safer without adding armour, said Major Amber Walker in a Darpa video, by instantly improving mobility on different types of terrain. The wheel has been configured to change from a circular wheel to a triangular track within two seconds while the vehicle is still in motion. Enabling the driver to drive at high speed on roads, and continue driving through diverse off-road terrain using the tracks.
During testing, the vehicle equipped with these re-invented wheels changed from wheel mode to track mode at speeds of 12 mph, and the reverse in 25 mph. While in wheel mode, the vehicle achieved speeds of 50 mph, while in track mode it moved at 30 mph. “This shape-changing locomotion technology could enable vehicle to tackle a wide array of terrains at surprising speed,” said Dimi Apostolopoulos, a CMU Robotics Institute senior systems scientist who led the project at NREC.
This group of researchers is definitely not the first to reinvent the wheel. However, they are the first one to come up with a prototype that don’t require the driver to first stop the vehicle before shifting the wheels from one mode to another. That feature can be critical especially during combat situation where the driver always need fast maneuverability.
Electric In-hub Motor
Defense Advanced Research Projects Agency (DARPA) recently unveiled ‘extreme’ in-hub electric motors for vehicles with military applications. The 100 kW electric motors with 3 gear stages in a thermal management system are all fitted in one wheel.
Putting motors directly inside the wheels offers numerous potential benefits for combat vehicles, such as heightened acceleration and maneuverability with optimal torque, traction, power, and speed over rough or smooth terrain. In an earlier demonstration, QinetiQ demonstrated a unique approach, incorporating three gear stages and a complex thermal management design into a system small enough to fit a standard military 20-inch rim.
QinetiQ wins DARPA electric hub-drive design and development contract
The US Defence Advanced Research Projects Agency (DARPA) has announced a $2.7m investment in QinetiQ’s electric hubdrive technology, bringing a new era of vehicle design a step closer. QinetiQ is to develop an electric hub-drive to improve survivability and mobility of future military ground vehicles for the US Defense Advanced Research Projects Agency (DARPA).
QinetiQ’s hub-drive seeks to improve mobility through enhanced power, torque, integral braking and high efficiency, in a unit that can be contained within a 20″ wheel rim. It aims to increase survivability by removing drive shafts and gearboxes, which can become lethal to occupants in the event of an IED detonation beneath the vehicle. The absence of these components could also reduce weight and open up future design possibilities, such as fully independent suspension with significantly increased travel.
QinetiQ overcoming these obstacles by integration of a small, powerdense permanent magnet motor with a three-speed planetary reduction gearbox and liquid-cooled friction disk brake, packaged within the space-claim of the standard 20” wheel rim. The motor design has demonstrated capability to deliver power to exceed the power-to-weight ratio of present-day military platforms.
Incorporation of a multi-ratio integrated gearbox allows the hub performance envelope to extend to both high-tractive torque at low speed for obstacle crossing/gradability, and to high vehicle speeds for on-road use. Using a cooled integrated friction brake allows for dissipation of braking energy far in excess of the rated power of the traction motor to ensure full braking capability. This system has been successfully demonstrated to TRL-5 within the space claim of a standard 20” military wheel rim. This effort takes the state of the art a significant step closer toward wide adoption of hub drives as a critical building block in the HED vehicle architecture.
Dr David Moore, Director of Research Services at QinetiQ, said: “Like cavalry horses throughout history, vehicles risk becoming less mobile as they are loaded with more armour and weaponry to meet the evolving demands of warfare. Our hub-drive tackles that threat by combining optimum performance with a significant weight saving, which is critical for mobility. It also introduces a far greater degree of architectural flexibility, enabling vehicles to be configured in ways which offer greater protection to their occupants.
“GXV-T’s goal is not just to improve or replace one particular vehicle it’s about breaking the ‘more armour’ paradigm and revolutionising protection for all armoured fighting vehicles,” said Kevin Massey, Darpa programme manager.”
Multi-mode Extreme Travel Suspension (METS)
One of the more exciting and groundbreaking technologies is the Multi-mode Extreme Travel Suspension. This equips vehicles with a suspension that can raise wheels 30 inches or drop them 42 inches, and each tire is controlled separately. That means that a vehicle can drive with an even cab, even when the slope is so great that the wheels are separate in height by six feet. It also means that the vehicles can get to hard-to-reach places quickly.
Pratt & Miller’s METS system aims to enable high-speed travel over rough terrain while keeping the vehicle upright and minimizing occupant discomfort. The vehicle demonstrator incorporates standard military 20-inch wheels, advanced short-travel suspension of four-to-six inches, and a novel high-travel suspension that extends up to six feet – 42 inches upward and 30 inches downward. The demonstration showed off its ability to tackle steep slopes and grades by actively and independently adjusting the hydraulic suspension on each wheel of the vehicle.
Enhanced Situational Awareness using wide angled cockpit with virtual reality
DARPA’s released a concept video that showed how the GXV could improve situational awareness. Armored vehicles have lower situational awareness than other types of vehicles, so the agency’s solution is to have wide-angle cockpits like a jet fighter. The concept would provide the driver with a closed cockpit that incorporates visualization technologies to provide wide-angle, high-definition visibility of the outside environment. The video showed the display as able to highlight optimal routes over difficult terrain, show both infrared and terrain classification views, and visually track allies and adversaries. It also includes autopilot abilities, allowing the driver to focus on strategic activities and decisions.
But there are also breakthroughs focused on getting rid of windows and making crews able to move faster and more safely. The Virtual Perspective Augmenting Natural Experience program allowed vehicle crew members to drive a windowless RV with better visibility than a normal driver.
Traditional combat vehicle designs have small windows that improve protection, but limit visibility. GXV-T sought solutions with multiple onboard sensors and technologies to provide high-resolution, 360-degree situational awareness while keeping the vehicle enclosed.
The Off-Road Crew Augmentation program, meanwhile, draws an estimated safest path for drivers moving off-road, and it can do so with no windows facing out. That means vehicle designers can create a next-gen vehicle with no windows, historically a weak spot in the armor. Ultraviolet light from the sun slowly breaks down ballistic glass, so “bulletproof” windows aren’t really bulletproof and will eventually expire.
Not only can they see what would be visible from the vehicle thanks to LIDAR, but they could also “see” the environment from a remote perspective.
Honeywell has Developed Virtual Reality Vehicle Windshield for DARPA
Honeywell engineers completed research and testing of a virtual window technology as part of the Defense Advanced Research Projects Agency’s (DARPA) Ground X-Vehicle Technologies ( GXV-T) program. During testing, an augmented and virtual reality headset along with a wraparound display enabled operators of a windowless vehicle to effectively see what was around them. This is the first case where a natural viewing experience has been achieved in an indirect, windowless driving system, officials say.
The company has designed a wide-angle, high definition view of the outside, “potentially allowing the operator to track optimal routes over difficult terrain, review infrared and terrain classification views, and see allies and adversaries,” according to a company statement. This shall provide improved physical and electronically assisted situational awareness for crew and passengers, one of the goals of DARPA.
Engineers leveraged the company’s “high-speed graphics processing, human factors design and display systems to create a virtual landscape that enables driving a windowless vehicle over actual terrain at operationally realistic speeds,” says Brian Aleksa, senior technical manager, Research & Development, Honeywell Aerospace. “After bringing a smart design to life with real-world testing, we’ve developed a windowless display that overcomes traditional challenges associated with motion sickness and eye strain. Our solution proves that a safer closed-cockpit experience is possible. There is plenty of future growth and potential application for this technology in both military and commercial markets.”
Earlier the Honeywell had successfully tested virtual window systems by driving a fully enclosed vehicle on a rugged, off-road desert course. As part of the test, professional drivers maneuvered through the track at speeds of more than 35 miles per hour. They drove the windowless vehicle using 160-degree “battlefield” views through the virtual window display.
Earlier, Doug Harris, Honeywell’s advanced technology manager in crew interface systems, enumerated many challenges to be overcome: “The ability to put very high resolution images up on a big wrap-around window and then be able to process all that data,” Harris said, “that is a big computational problem, and when you talk about computation that adds up to power, which means a heavier vehicle,” said Focusing on human factors is also important, Harris said. “That was one of the things we thought was really strong about our proposal to DARPA was the human factors content that we have in our program.”
Off-Road Crew Augmentation (ORCA)
A second CMU NREC technology demonstration, ORCA aims to predict in real time the safest and fastest route and when necessary, enable a vehicle to drive itself off-road – even around obstacles. In Phase 2 testing, drivers using the ORCA aids and visual overlays traveled faster between waypoints and eliminated nearly all pauses to determine their routes. The team found autonomy improved either vehicle speed or risk posture, and sometimes both.
Walker said GXV-T performers are pursuing a variety of transition paths for the new technologies.
“DARPA’s excited about the progress made to date on the GXV-T program and we look forward to working with the Services to transition these technologies into ground vehicle platforms of the future,” said Walker.
Leidos eyes technologies for stealthy vetronics able to hide combat vehicles from sensors
Leidos experts will try to find ways for vehicles to hide from infrared and visible-light sensors, radar, and microphones. Leidos also will try to find ways of reducing or hiding dust clouds that moving armored vehicles generate, as well as hiding a vehicle’s tracks on the ground. Reducing the signature of ground vehicles could result in lower probabilities detection and attack, DARPA officials say. In a combat situation, vehicles with lower signatures also might develop a tactical advantage through a longer effective standoff range.