OT: DARPA reinvents the wheel.

I wonder what the wear on that thing is, and how robust it is against mud and stones, etc., in the track. If anybody learns anything more, please post here.

I forsee the day when a Humvee is under hostile fire but the electronics that control one of the wheels fails and they're trying to fall back with three round wheels and one triangle, the occupants thinking "Well, I'm glad the folks who had to rock this thing out of that muddy ditch in Georgia the last time had their lives made a little easier."

Like these perhaps? (0:19) but not this:

Stolen NASA ideas and technology for rover type missions.

Hahaha!

The movie that 20th Century Fox expected to be the hit of 1977 (and they actually built that thing):

Sometimes you're quite sensible.

The only advantage over a round wheel is that the contact area is a bit bigger. The disadvantage is complexity. Just more wheels would work; add redundancy instead of complexity.

My father owned an apartment building in North Hollyweird during the time it was parked at the builders auto shop, usually with at least one flat tire. I never saw it go anywhere. Nice idea having 4 spare wheels, where the vehicle can blow one tire per wheel, and still continue operating. However, the ground clearance, angle of approach, and angle of departure are minimal making it rather useless for off-road operation. The outboard wheel bearing mounts and guards make climbing over boulders difficult as the outboard guards will hit the boulder before the forward wheels will clear the boulder. Personally, think it might drive better resting on the apex of the triangular wheel affair, thus giving it 2 spare tires per wheel that can be easily rotated into position.

Need less ground pressure and more redundancy? No problem with a self propelled modulular transporter:

Right. A few of those tires could go flat and the thing keeps going.

More wheels and fill them with liquid rubber instead of air like some APC's do.

DARPA was developing an 8-wheeled vehicle where all the wheels stear and they can be raised individually. I saw it on TV once but can't find a single reference on the web.

Which reminds me - high performance cars include something called torque vectoring. Anybody have a notion about that?

I figure there must be a few motorheads in this group -

Daily quiz: design a track, mathematically, where this shape is optimal.

Nah, the angle is better. When you get into mud or snow up to your axles, you have zero purchase with round wheels, whereas those ones would still work--until they don't, of course.

Cheers

Phil Hobbs

That triangular trackie thing looks like the moral equivalent to about an 8 foot diameter wheel.

That would be cool, Humvees with big side-paddles, like old Mississippi River steamboats.

early systems just applied the brake on the unloaded wheel, more advanced systems have a tricked out differential with clutches that can make the loaded wheel rotate slightly faster

I like to think that engineers working for DARPA are pretty smart and have considered this in some fashion. The article doesn't provide enough detail as to how the whole rig works.

One would hope there was some "fail safe" setting so that if you lose electrical power to one or all Transformer-mechanicals or whatever it would fall back to some default form that you could at least drive on like four regular wheels or four tracks, depending.

The big advantage would be ease of servicing if those wheel units can be swapped in and out as a whole as easily as a tire but could give you a good part of the advantages of a fully-tracked vehicle. Tracks get beat to shit pretty rapidly and it's a labor-intensive process to swap the tracks in and out on a fully-tracked vehicle