Crusher - futuristic Unmanned Ground Combat Vehicle

Safeguarding the soldier is the key aim of the Unmanned Ground Combat Vehicle – giving soldiers enhanced stand-off capability was the reason DARPA funded the Grand Challenge and backed up again two years later with the second challenge and is now holding the challenge in an urban area – such contests dramatically accelerated research into autonomous navigation and identified the most capable people to for the military to work with. The National Robotics Engineering Center (NREC) is part of the Robotics Institute in Carnegie Mellon University's School of Computer Science, unveiled Crusher last week. Carnegie Mellon vehicles finished a close second and third in the Grand Challenge though everyone knew they were at the bleeding edge of robotics knowledge, the Challenge just confirming it. Crusher demonstrates just what we can expect to see on the battlefield a decade from now. In what might well be seen as an offspring of the Grand Challenge, “Crusher” is a new breed of UGV – an NREC-designed, six-wheeled, all-wheel drive, hybrid electric, skid-steered, unmanned ground vehicle. The bohemoth weighs 14,000 pounds fully fueled, and is designed to carry a 3,000-pound payload – at this 17,000 pound total weight, two Crusher vehicles can be carried by a single C-130H aircraft and dropped into any region in the world. Once on the ground, Crusher can carry up to 8,000 pounds of payload without compromising its mobility – read that as 8000 pounds of smart stuff – any combination of cargo, armour, armaments, or surveillance equipment. Crusher is also designed to withstand extreme terrain, with the ability to take in its stride regular impacts with trees, boulders, fences, tree stumps and ditches at high speed. With six wheel independent drive, Crusher can go up and over almost anything, and if in the process it should get upside down, it moves its wheels to the other side of the vehicle and starts all over again. Crusher's hybrid electric system is silent, using a high-performance SAFT-built lithium ion battery module which delivers power to the six, in-wheel UQM traction motors located in the hub drive system of each wheel. Much, much, more … interesting stuff!

The suspension is designed by Timoney offering a remarkable 30 inches of travel with reconfigurable ride stiffness and ride height.

Crusher and its predecessor, Spinner, demonstrate the realm of the possible with regard to a combination of autonomous behaviors, hybrid electric propulsion and robust vehicle design so we should start the story with reference to Crusher’s dad, Spinner.

Spinner was designed to take maximal advantage of the uncrewed UGCV aspect. Whereas the DARPA challenge was all about working out how to replace the capabilities of a human being (navigation/driving), and contestants chose conventional proven vehicles designed to incorporate a driver, Spinner could use the entire internal space with complete design freedom.

The most obvious manifestation of this in Spinner’s design was its ability to invert itself. Humans aren’t comfortable upside down but a purpose built machine doesn’t mind at all. Ingeniously, this overcomes the problem of the vehicle being capsized and immobilised. With wheels transferable to the other side of the carriage, the Crusher and its direct forebear, Spinner, can drive out of anywhere.

The advantages of removing the driver go well beyond the inversion though, as the large central, payload bay rotates to position payloads upright or downward. In addition to rollover crash survivability, the hull, suspension and wheels were designed for extreme frontal impacts such as striking a tree, rock or unseen ditch at high speed.

With a brief of being able to cover extreme terrain, and with navigation still in its infancy, Unmanned Ground Vehicles must be able to surmount terrain obstacles, as well as survive and recover from impacts with obstacles and unpredictable terrain. They must also be fuel efficient and highly reliable so that they can conduct long missions with minimal logistical support.

Resilience was imperative – manned vehicles have people to fix them when things go wrong, whereas unmanned vehicles do not. An unmanned ground vehicle must have the ability to withstand considerable abuse during a mission and still get the job done. Such abuse is common to unmanned vehicles that are controlled by distant teleoperators or by semi-autonomous sensors and software.

To focus prototype development, DARPA established primary design metrics: • Obstacle capability (1m+ positive, 2m negative, 35 slopes) • Resilience (withstand abusive use while remaining lightweight) • Endurance (14-day missions; 450 km range without refuelling) • Payload Fraction (more than 25% of gross vehicle weight)

...continued