Roller skating powered armor?

Question

One common problem with powered armors is their limited endurance. This could be remedied with electric roller skates as an efficient and faster way of locomotion, capable of maintaining its speed even in slav squat.

Designing such skates, however, is a pain in the...
Anyways, a roller skate like that would have to meet the following criteria to be of use:

• Enable quick recovery from, or prevent unwanted falls altogether
• Be durable
• Be retractable
• Could strafe/change direction without the wearer moving the feet
• It also has to work on all sorts of terrain (sand, rocky mountains, tall grass, snow, and mud), except for stairs
• The weight shouldn't be a concern as the rest of the armor is Pneumatic artificial muscle, UHMWPE, and some shear thickening fluid

How can these problems be overcome?

Answer 1

This is... well... it's a bad idea

The short (but not very valuable) answer to your question is yes, every one of those design limitations could be overcome. But there's simply too many reasons why this shouldn't (and realistically wouldn't) be done.

• Roller skates work on firm, smooth surfaces. They're usless everywhere else. This would suggest roller skates on combat armor would only be useful in urban warfare, but...

• Streets and sidewalks are frequently filled with debris, especially after combat, which makes them little better than every other non-skatable terrain.

• To make things worse, bipedal combat armor has such an enormously high center of gravity that rolling along on roller skates would almost guarantee being tripped or simply falling over. Consider rolling along, minding your own business, when a bomb explodes nearby. Human reaction is to move one leg out to brace and keep one's self from falling over. Dang... I had a roller skate on and in the fraction of a second of reaction time stepped out before retracting.

• They add complexity where no complexity need exist. What happens when the bearings burn out? Or a bolt breaks? Or they simply get jammed with some wad of weeds? This design, like the French Chauchat machine gun, suffers terribly from small-moving-parts-in-muddy-weather syndrome. And heaven help the soldier who experiences a failure in the retraction mechanism.

• Perhaps the worst problem is the potential breakdown of the drive mechanism. Combined with being extended, suddenly you have no traction at all. Your combat armor must be designed (to its detriment) to allow the legs to rotate so the edge of the skate can be brought to bear to push forward, otherwise you simply sit there (or roll down hill, depends on where you are...).

People can roller skate really well because they're not carrying armor and equipment and a ton of other material above their waist and they're basically only thinking about roller skating while they're doing it. Distraction and a backpack of any kind and you'll be thanked by the enemy.

In the end, soldiers would simply never use the skates.

Answer 2

Why go roller skates? The wheels are small and therefore cannot handle rough surfaces.

If you increased the size of the wheels, you could end up with an off road Segway

Personally I'd look at a folding motorcycle on their back. The motor is electric and is contained in the wheels. The cycle itself is just a frame and the power is supplied from the suit.

If you wanted to be real fancy, the suit could grab the wheels and transform itself into the motorcycle a bit like the motorcycles from Terminator Salvation

Answer 3

Based on the desire to keep "skating" as an option, but the obvious advantages of treads that are mentioned in comments, may I recommend an existing technology, the Reconfigurable Wheel Track. These wheels can transition to operate with a track when on difficult terrain, and then morph back into wheels to move fast on friendly terrain. That's probably the closest you'll get to rollerskates that are useful in combat, and it comes with the added advantage of being an actual developed technology.

Answer 4

From a practical standpoint, (if you have to do this at all - say, if it's part of the funding requirements from the big-boss) I would agree retractable wheels - ideally with the "failsafe" position being retracted in case of power failure. This means that under most circumstances you stick with normal biped locomation - the wheels are for rapid transport on roads or pavements, when you don't have the time or room to call in a dedicated transport unit.

For stability, go with 3 wheels per foot - perhaps one behind the heel, and one either side of the toes? This also determines where the wheels retract to (2 at the top/front of the foot, one behind the heel/ankle). A triangle is the most "stable" shape, the larger the better. However, having all the "drive" at ground level will cause issues staying upright - ideally you add some sort of jetpack or maneuvering thrusters to the torso to reduce the resulting torque. (This may also allow for longer and/or higher jumps to avoid un-skateable obstacles)

For agility ("strafe/change direction without the wearer moving the feet") I would suggest some form of Omni Wheel or Mecanum wheel.

Making it work on the different terrains is hard - we can't even get full-sized cars or even dedicated offroad 4x4s to relaibly operate without under the wide variety of circumstances you suggest, at least not without either swapping the wheels/tires out or scaling them up to tanks or monster trucks. This is going to require fairly large wheels, and possibly some sort of retractable stud/spike system to adjust the grip and footage to suit the terrain.

Answer 5

"All terrain" is not possible for small wheels, and difficult for most solid wheels.

See 'Snowcrash' by Neal Stephenson for a skateboard which can handle moderately difficult terrain and stairs. The wheels have extendable wedges instead of a solid surface, and the skateboard constantly uses radar to determine how far it should extend each wedge. It must be strong enough to push the rider up, and long enough to overcome the obstacle and let the next wedge start pushing, like when going up stairs.

Consider extra legs and semi-autonomous driving. At that point, it's a small tank like a 'Ghost in the Shell' Tachikoma, which is also cool. The Tachikomas stayed on roads and flat hard surfaces, using harpoons and tethers to climb buildings when they met troublesome terrain. They could dance somewhat, using independent wheels on independent legs, while driving on roads with potholes. They could have claws on the ends of their legs for short periods on moderately-hard surfaces. But you could not have a Tachikoma out in the grasslands or desert. They would need track feet or a vehicle.