Pogo pack exoskeleton lightens your load

[chumley]

On flat surfaces, the pack’s mechanics didn’t make that much of a difference. On steep hills, it really came into its own. When you’re doing those steep thigh-burner steps, at the moment you’d really feel the full weight of the load pulling down and back, it’s like a giant hand coming along and lifting the pack off your back for a split second.

It’s a really amazing feeling, after decades of backpacking, to have a giant hand come down and hold your pack up at a crucial second. It’s completely unexpected. It’s like suddenly being able to fly or breathe underwater or grab a hot coal.

And the Pogo Suit didn’t fare well in the lab. Sugar and his team saw a metabolic cost decrease, but only enough to justify the suit’s 12-pound weight itself. The Army lost interest, but joked they’d buy it just to beat up recruits.

Your tax dollars at work!

https://asunow.asu.edu/20170414-solutio ... ut-it-test

[flagscott]

It's been a while since my last physics class, but I don't see how this can decrease net energy expenditure. There is no net external force acting on the pack+human, so the total energy required to move the pack from point A to point B on the trail can't be different from a non-mechanized pack of the same weight. The upward movement of the pack should create an equal downward force on the frame, right?

Any engineers here that can explain this?

[friendofThundergod]

@chumley
Interesting...the Army/military has been working on this for awhile too, mainly in a response to the fact that the mountains in Afghanistan were breaking off soldiers, due to the excessive combat loads...In fact, a few soldiers in our unit took part in a testing at Yuma Proving Grounds..

The appropriately named Human Universal Load Carrier, or HULC, is a wearable exoskeleton that allows soldiers to carry up to 200 pounds for over 12.4 miles on a single battery charge.

There is even a "burst" mode that moves the run up to 10mph for short periods

[chumley]

@flagscott
Send the inventor an email. He's in the ASU directory.
Or check out his presentation

Sugar will present his work — which includes a jet pack exoskeleton enabling a wearer to run a four-minute mile, a Spider-Man suit that can climb any surface, and a cool suit that lowers ambient body temperatures 20 degrees — this month at WearRAcon, the Wearable Robotics Association Conference organized by the Wearable Robotics Association, from April 19–21 in Phoenix. The conference will cover areas including health and fitness monitoring, recreation, business and military applications.

@friendofthundergod
This project was commissioned by the army.

The Army came to him and asked him to come up with a way to make carrying a heavy load easier....The Pogo Suit was designed to decrease the metabolic cost of carrying a heavy infantryman’s load, around 70 to 120 pounds.

[DallinW]

It's been a while since my last physics class, but I don't see how this can decrease net energy expenditure. There is no net external force acting on the pack+human, so the total energy required to move the pack from point A to point B on the trail can't be different from a non-mechanized pack of the same weight. The upward movement of the pack should create an equal downward force on the frame, right?

Any engineers here that can explain this?

If I had to guess it's because you are somehow saving calories due to the weight distribution, which is more of a biology question than a physics one. It's gets tricky equating calories to physical energy, from what I understand. My limited physics knowledge (I took Mechanics and Electromagnism 2 years ago) agrees that the amount of force would be the same. Interested to see his response if you email him.

[CannondaleKid]

I'll admit my one-and-only physics class was 50 years ago, but unless they have come up with some kind of anti-gravity contraption, I see no way how this could work.

Let's take a moment to think about this 12 pound pogo pack...
For every time it drops down to relieve a certain mount of force (gravity) it must then pop up, ADDING same amount of force, in effect making the pack weigh MORE than it does statically for that moment in time.

Albeit very simplistically, it seems to me, when the packs pops up, you will weigh more (12 lbs?) and when it drops down for that short amount of time you will weigh the same amount less.
However... without the ever-elusive 'anti-gravity device' the ups & downs will average out, and all that changed is you added 12 lbs of weight to your pack for what? So you can be hoppin' and a boppin' as you hike, and shaking up your insides as well as your booty? Not me.


Thankfully MY taxes aren't being wasted on it. (How can that be? Because my 'income' is so low I owe no taxes)

[nonot]

So normally, when you jostle around, the pack energy is lost by rubbing against your body. It is storing energy (see the battery towards the beginning) by capturing the wasted energy. Then it works by expending that energy whenever your body moves down, by not allowing the pack to move down. When you move back up your body catches up, but is lifting less weight because you are not lifting the pack weight upwards. Thus it feels lighter as you step upwards.

It works similar to the energy saving shoes that compress when you step on them and release the energy when you pick your foot up, it is just temporarily storing energy that would go to waste into friction and the ground and releasing that energy in the direction you are travelling. Most save about 2-10% of the energy overall, so it isn't a huge difference but sometimes every bit helps.

[jacobemerick]

I'm just waiting for the day we'll be using BigDogs to haul our 200 lbs of camping gear up and down the mountains while we skip around and smell the flowers.

[hikeaz]

.................. when the packs pops up, you will weigh more (12 lbs?) and when it drops down for that short amount of time you will weigh the same amount less.
However... without the ever-elusive 'anti-gravity device' the ups & downs will average out, and all that changed is you added 12 lbs of weight to your pack for what? So you can be hoppin' and a boppin' as you hike, and shaking up your insides as well as your booty? Not me.

He should spend the time and energy developing lighter ammo with the same stopping power.