The ESOX Group is advancing the concept of a robotic army mule with its X2 uncrewed ground vehicle (UGV) by simplifying its design, placing electric motors directly inside each wheel for better off-road performance and greater stealth.
Infantry has been around since officers figured out how to get soldiers organized instead of fighting in melees like football hooligans on a Saturday night after 12 pints of lager. Though there have been great advances in military technology and tactics, there still remains the perpetual problem of the Last Mile.
Essentially, the problem is that even though you may have an incredible logistical network that spans the globe and puts large commercial equivalents to shame, there is still that last gap between the nearest road and the battlefield where soldiers must haul hundreds of pounds of supplies through jungle, over mountains, or across broken, muddy ground.
Traditionally, the solution – aside from squaddies hauling insane loads on their backs – has been to use horses and mules to do the job. That remains true in the 21st century, but today major militaries are looking for robotic platforms to replace their equine equivalents.
The challenge is finding the right way to propel these robotic mules. By definition, they must be off-road vehicles capable of handling rough terrain. However, they also need to be smaller than a standard 4x4 and as stealthy as possible to avoid detection. In addition, traditional drivetrains – even electric ones – present difficulties that are better avoided.
Conventional drivetrains rely on a central engine or motor with power distributed to the wheels by way of differentials, driveshafts, and gearboxes. These components introduce mechanical complexity and introduce inefficiencies, causing a loss of torque in mud, sand, or rubble. They also generate heat and noise, which enemy sensors can zero in on.
ESOX has addressed this by moving the motors from one central point to installing direct-drive electric motors in each of the wheels in the form of direct-drive electric motors.
The result is a 661-lb (300-kg) vehicle capable of carrying its own weight in payload. Its direct-drive setup eliminates the gearbox entirely while boosting torque to 1,000 Nm (737 lb-ft) for handling severe terrain. It is powered by solid-state batteries to reduce fire risks while doubling energy density compared to conventional lithium-ion cells.
In addition, the vehicle was developed using digital twin technology through ESOX OS, allowing for rapid modifications and updates.
"The X2 solves the known UGV core weaknesses with four Theron in-wheel motors delivering combined torque of 1000 Nm, 250 Nm per corner and that torque goes directly to the wheel, eliminating the gearbox and driveshaft entirely," said Devan Roberts, VP of Defense Programs. "In-wheel motors delivering more power and torque than any other electric motor on the market means no terrain, gradient or payload will stop you."
Source: ESOX Group
