You set the speed you want; you get on, you start moving.

But you don't actually go anywhere. This technology people have realized for a really long time is perfect for virtual reality

Because you could walk somewhere and actually use your body but not leave the confines of your own home

Okay here we are in California. We are at a company called Infinadeck. This is a small engineering outfit

These guys make a 360 degree treadmill the one that's in the movie ready player one so the interesting thing is they're really small company

But they've got a really cool idea, so let's go check out how this thing works.

All right, so this is George, and he owns Infinadeck right?

Yeah

All right

And basically Infinadeck is a 360 degree treadmill technique. That is

Is it safe to say that we've got treadmills on top of treadmills here?

It's a treadmill made of treadmills

Okay. Treadmill made of treadmills

So you can think of it as you've got one axis of rotation here and each individual

Treadmill can move in this direction as well, right?

Yeah

So how do you ?

So it's a combination right obviously if you want to go X. This is our X direction. This is our Y

X is nothing, but a treadmill you know like any other treadmill the Y it's nothing, but the smaller treadmills

right now we're using the Vive tracker on you

Right, so where is the, there they are right there.

So your tracker's on your rear

We kind of artificially take you about

seven or eight inches in front of that to get the middle of your CG

And this tries to keep that middle of the CG in the middle of the treadmill right there.

Oh I got you. So the, so the feedb-

that was one of my main questions is what is the feedback loop? It's a positional feedback loop.

Yeah, it's fairly simple right now. We're making it better this that's the part

We're gonna just keep improving for ever, years and years and years

really? so the goal so you have an object and then

Oh, I get it. It's this is, this is called

They're very visual

This is a semi autonomous command position sensor. That's the best

Specific way to say that, right?

Now what we're also doing on this one is

You put foot trackers on when you combine the foot trackers the headset and your and your hand controllers

You now have six different

Points that is tracked on you, and that's enough for us to give you an avatar

George Jr told me if I screwed this little VR tracker into the bottom of the camera

We can insert that camera into the virtual world

Which of course we had to do

So we're ready?

Yeah

So I just I just get in?

Yeah go ahead, so

Alright

Let me help you a little

Okay? So first let's do your feet

Alright

This is the CG you're gonna put that on.

Make the tracker meet like directly behind your back

Okay

So go on, put your headset

This feels like I'm actually getting in the Oasis here

Oh wow I can see the camera, in the virtual world

If you look towards me you should see the two controllers?

What the heck man!

So we're gonna have you do now

Okay, okay. I'm trying to. This is just normal VR.

So I can actually see the ring now

That's something I didn't expect, so I can, it's there

Yeah

Alright so now that's

I see my body too - what's up with my body

So we're gonna sync that with you.

So if I can have you stand with your legs straight down,

and your arms straight out to your sides, like a T-pose?

Three two one

Did it work?

Oh I can see my body!

Wow

Alright

Okay, that's rad. That's really rad.

Okay, gotcha so

So right now you're tracking the position of my hands and my feet

Dude that is messed up! This - I'd like him - Alright

So I can see the camera, the tic-tac there, but what's more important is I can also see this ring

And Griffin why did you say you have this ring in here?

So this is there to kind of lock you down in the real world without being too much of a burden to say

So this is like you know when you do an integral you get the plus C at the end

So this is a boundary condition for me to kind of lock my brain into both worlds

so this is like this tells me where I'm at virtually and

Like actual my body, right?

Absolutely

Okay so, are you ready to start walking?

I'm ready to start walking

We're gonna recommend you have your hands on the range when you first try this just so you get used to

That's okay, so when you start. Yeah. I thought it would make sense for you for it to put me in the center, okay

So now right?

What is trying to do is this trying to keep the CG of my back in the center of the ring, right?

So I'm gonna touch this and as I walk

Okay, it takes just okay. I'm there. Okay. I don't want to hit that tree

So I'm gonna turn this way

Okay

So I can't really tell if I'm walking 90 degrees or not

Okay, so there's inertia in the rollers, okay? I thought there might be. So if I move backwards

It's gonna keep me there I move forwards

So it takes just a second

Just a couple seconds on the Infinadeck, and I instantly understood the problems that these guys have to overcome

It's pretty interesting

It seems pretty simple: whatever direction a person walks, the Infinadeck moves in the opposite direction, whether it be X or Y, at

the exact same velocity and acceleration. Think about a normal treadmill: your brain is doing all the processing. Your brain is constantly

Solving the equation a treadmill velocity plus body velocity equals zero if at any point

You don't solve that equation correctly you start moving relative to the treadmill. This is a very similar problem, but it's much harder

It's harder because there's two dimensions

That's the obvious one

But it's also harder because the processing isn't happening in your brain. That processing is offloaded to the Infinadeck

which, oh by the way, can't read your mind.

There's a delay time for the Infinadeck to figure out where your position is and try to change that...

Yeah. Yes.

...and if it tries to

do it too quickly you know you can have an overdamped and under damped system is that correct? Yeah.

Is that the right terminology?

So, yeah

So at the moment what we're currently doing we're trying to make it so that the acceleration on the user in

any way that they're not really tried experience is never more than 0.1 Gs got it

Oh that seems to be about a good amount to not really be, you know disturbing for the user. Okay.

We're trying to figure out where exactly that isn't how to do that if I walk forward

I'm gonna feel an acceleration in one direction on my body because I'm pushing against the floor, right

but then the floor is gonna move, and it's gonna move my body in the opposite direction, so I'm going to feel an

acceleration that's negative, which is strange for, you know, a normal walking around human. Then, once I hit a steady state velocity,

I'm gonna level out that acceleration in my mouth. My body's gonna be cool with it right, but the moment I stop

That's a change in velocity and the Infinadeck has to accommodate for that. It has to move you back to the center

gracefully and one thing that happens is if it tries to move you back too fast

It'll overshoot, and then it has to correct. So this is a really interesting engineering

problem because it doesn't have

perfect knowledge of intent. Like, that

that's the difference with your brain you have intent and so when you're walking in a normal treadmill you get to

choose everything, right?

but you have to understand over the last few years

we had to, you know, build and modify the Infinadeck too

along with the control system, and there's only a few of us, so. Well. It's been challenging all around.

This is why the problem is interesting because when you're walking in the world

Right now my acceleration is zero

And then when I stop I'm used to imparting acceleration to my body

But that doesn't happen till later

Yes, it's a work in progress how far you go back. It's

That's clever. That's it's a challenge. That's a that's a hard math problem one thing

I thought was really cool is you can use this to be a different size in the virtual world just by changing a

Constant right you can scale

How many steps it takes to get around in the earth?

Just by a scale factor, but literally a scaler, that's often. Oh, there's the same boat look at that

It's a dude. It's like

I want to jump

I'm just

Too small to get it

Too small to go to my boat and *laughs*

That's fun. That's really fun that the model... There's my bench. Look behind you, there's my bench before

In engineering we have these assignments called technology readiness levels

There's nine of them, and I would say this is somewhere between a six and a seven

Which means there's a working prototype that works, and they're just refining the subsystems they're about to go to production

So it's really cool to be able to walk on

This Infinadeck before it goes out into mainstream production and see the behind the scenes engineering things

they're having to solve. It's really interesting. So, it's clear George knows all this

I mean he instantly understands all the variables I asked him about

That how tall the person was like if you think about it your center of mass is at a different length and so that moment

arm is different you have to deal with inertia differently like from the bottom of it. It's really interesting anyway

This is me talking to George and you can tell he totally gets it. I I can imagine that the

the inertia

Overcoming that inertia is different for each person because if I'm 175 pounds and I move here

It takes a certain amount of torque

I'll cut the deck off now. It takes a certain amount of torque for these motors to move me and

That's going to change based on the size of the person, is that correct?

That's correct that. It's more about your acceleration than the inertia.

The the deck is capable of moving a lot faster than you can move.

So so we could pull your feet out from under you if we ever, you know, had it set to do so.

So all the algorithms stuff will will have more to do with other variables,

like your CG, CG imbalance.

And there's a moment arm between the distance from my feet to where my CG is, right?

So, so the acceleration that you put there, there's gonna be this lag time in my brain where I try to counteract that, is that correct?

Very much.

All right, this is the part of video where I tell you about the sponsor and, you know, a lot of people fast-forward through this part,

but you know this is the important part because we wouldn't be doing this if I hadn't have listened to Ready Player One on

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Thank you for considering that. Last thing. I wanna say thanks to the guys at Infinadeck.

A treadmill made of treadmills, that is insane.

You're there man, this is just a control systems problem at this point, isn't it?

We just need some control engineers. We ought to hire a couple.

That's what this is at this point.

At this point, it's just computer stuff and math so this is doable

I hope you enjoyed this video enough to subscribe. If you do there's a little bell beside the subscription button.

If you haven't enjoyed it enough to hit the bell to get a notification on your phone every time I upload, then don't.

That's completely okay. Anyway, I'm Destin. You're getting Smarter Every Day. Have a good one. Thanks for learning with me

You're gonna fall. You fell. You jumped. Whatever. What are you doin'? Why you makin' noise?