字幕表 動画を再生する 英語字幕をプリント Hey, it's me, Destin. Welcome back to Smarter Every Day. A treadmill is a pretty simple device, right? 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.