I've been working with full motion simulators for the past two years (I even rode that simulator last week at MPI) and I must say that this is plain wrong. This is actually a great fit for VR simulation (see below):

> Actual linear acceleration is of limited value in simulation because...

Linear acceleration is immensely useful for sudden accelerations. Image a sudden linear acceleration (e.g. a racing car accelerating). You cannot recreate this acceleration by suddenly rotating. The angular accelerations would ruin the experience. Rather, you make a linear movement, and THEN you rotate the simulator (if you need to sustain the acceleration).

> you run out of room and have to apply an opposite acceleration, which can conflict with the simulation needs.

wrong again. If you move the simulator at slow speed, you can actually come back to the optimal position and the subject does not notice it (washout filter [1])

[1] https://en.wikipedia.org/wiki/Motion_simulator#Implementatio...

Gimbals are limited to ||acceleration||=1g. I guess there are some elements you miss from that, like when a roller coaster starts to fall (you experience <1g), or when a car takes off (you experience >1g). Here you can provide a bit of both and also gimbal action. There's also rotation effects (which I don't know if are felt) that can be mitigated too and better jerk simulation (not only acceleration, but variation of acceleration).

Actually if your whole simulation has ||aceleration||>1g you should be able to do it perfectly (save for jerk/rotation effects) with some large centrifuge: the rate of rotation of the large centrifuge dictates the "perceived gravity" and gimbals dictate the "perceived direction". In this sense it would be perfect if you could get a centrifuge with a gimbaled end in a 0g environment.

Hey NASA, I have this one little idea for the ISS... :)

NASA seems to think different. http://www.aviationsystemsdivision.arc.nasa.gov/facilities/v... https://www.youtube.com/watch?v=fhu_UldlP_E (in motion...)

I agree that rotation should be enough for VR purposes, and linear translation of the subject is not strictly necessary.

Any acceleration up to g = 9.81 m / s^2 can be easily simulated, and it can be maintained indefinitely. All you need to do is to rotate the subject so that the perceived acceleration is aligned with g, or keep it at an angle, to get a fraction of g. Interestingly, for VR you don't need to simulate velocity, as it cannot be perceived by the body.

Flight simulators have been using this approach for decades now, and it works really well: http://arabiansupplychain.com//pictures/300x200/CAE-simulato...

But this system looks to have the advantage of being able to simulate accelerations above g.

PS: Is gimbal a verb now?

I would love to see one of these platforms that's capable enough to feel right when playing Descent.

[0] https://youtu.be/rrUF8Dz84rE?t=329

Around 25 seconds into the video you can see how thick the cable is. I would guess probably an inch thick. With regular wire rope, the breaking strength of that diameter would be in the neighborhood of 80,000lbs[1] with the safe load strength closer to 16,000lbs. I'm guessing with regular maintenance and checking, it would be exceedingly rare to have a mechanical failure.

Additionally, the occupant is harnessed into the chair, bolted into what is essentially a spherical roll cage. Even with failure, I'm guessing there would be a crash but no serious injuries.

[1] - http://www.engineeringtoolbox.com/wire-rope-strength-d_1518....

You could make the floor foam blocks or a trampoline, but in concept it's very similar to the Skycam used for NFL games and they are very reliable. I've never heard of one coming down (and they have a lot more travel).

https://en.wikipedia.org/wiki/Skycam

I'm surprised they have the computers right next to it... and people standing there. I wonder how they mitigate the possibility of unintentional (error driven) movement?

Massive wires each under 1.4 tons of tension would make for quite a show if one did break

I believe with that cable configuration, Yaw motion isn't really possible. I'm sure it would help with motion programming with the VR, but perhaps true Yaw wouldn't be entirely necessary. Good questions though.

For your last question, I do think that's the way they would need to add Yaw if desired. Otherwise more cables and/or a different configuration would be needed.

As an example, check out the robocrane design from NIST: http://www.nist.gov/el/isd/gantry-2.cfm

It says "freely programmable trajectory in six dimensions", and there are indeed six cables, so yes it's supported. But any rotation of that object is going to be limited of course.

A motor under the platform that swivels the user, chair, and floor inside the cage would do it. But I agree with the other commenters that the video does not seem to demonstrate a yaw capability.

> slack

why cables are loaded at 1.5tons. Electric motors have incredible torque and those looked like some honking big motors.

Two quick answers:

1. Could it?

Depends what you mean by "cable technology like this". I haven't seen Robots, but this kind of constrained, multiple-degree-of-freedom movement would not be possible in an "open world" -- you have to have existing infrastructure, and for something like cables (which "operate" in tension only), that infrastructure has to surround the entire "vehicle". And cables have an effective practical length limit before you run into a number of physics barriers. Now, you could have something that operates by a cable pulling a car along a predefined route, but it would be a simple linear movement. Not only can you, we already do this: most ski lifts work this way. So do, for example, the SF cable cars.

2. Even if you could, should you?

The tl;dr here is that in the vast majority of modern cases, other technology is better. If you're going to expend a whole bunch of money on infrastructure, which is necessary for public transportation in general, why not make it something higher capacity? Lightrail, or high-speed bus, or really almost any other form of public transportation is more effective. Where the ski lift approach shines is in low-volume, low-speed transport across terrain that would be very, very difficult (read: expensive) to lay tracks or road across, like mountains. Similarly, the cable car approach shines in situations where rails offer questionable traction in adverse conditions, and a positive connection with something is hugely beneficial (like a very steep hill). There are always niche applications, but I wouldn't hold my breath for widespread use.

Come visit beautiful San Francisco! https://en.wikipedia.org/wiki/San_Francisco_cable_car_system

I think the wires would get in each other's way if you had pods in the same volume.

"Robots" is not a Pixar movie.

Do you get sick from driving a car or riding a bus though? Because I guess you could make the experience to be exactly like that. It's supposed to feel like a normal, natural motion.

It _is_ a Disney ride! I've ridden on it—tons of fun.

https://en.wikipedia.org/wiki/Star_Tours

The technical description:

> Star Tours utilizes hydraulic motion base cabins featuring six degrees of freedom, including the ability to move 35 degrees in the X-Y-Z plane. The simulator was patented as Advanced Technology Leisure Application Simulator (ATLAS), originally designed by Rediffusion Simulation[8] in Sussex, England, now owned by Thomson-CSF. The Rediffusion 'Leisure' simulator was originally developed for a much simpler show in Canada called "Tour of the Universe", where it featured a single entrance/exit door in the rear of the cabin and a video projector. The film is front-projected onto the screen from a 70 mm film projector located beneath the cockpit barrier. The Disneyland original has four simulators, while the shows in Tokyo Disneyland, Disneyland Paris, and WDW Disney's Hollywood Studio each have six motion bases.

Anyone knows scalable it would be? To start, everyone would need a VR headset, not that amusement parks are short on cash

So? She could be the chief engineer, but in the video she is the model, the stand-in, the demonstration person. Call it sexist if you want, but it is standard marketing practice to use young women/girls in promotional vids. Where movement is involved, models with long hair are also preferred as it shows the motion, something that again tends towards young girls. Smaller people also make products seem larger. Where the product involves a seat (cars, air travel etc) a really tiny person makes things look much roomier and more comfortable. Where the action is recorded at a distance people with clear skin but darker lips and larger eyes are more expressive, again trending towards females. Where there is any sort of perceived physical danger you pick models that, rightly or wrongly, are perceived delicate. Use a 250lb Army grunt with massive muscles (of any sex) and viewers might think they also need to be tough to enjoy the product. So this vid is following standard marketing practices in selecting a very standard model.

My point still stands. What would rigging for several non-small people on this thing involve? Looking at the angles on those cables, a 10-fold increase in payload might need a 20 or 30-fold increase in cable strength ... adding weight ... needing stronger cables.

After watching it a couple times more, I'm also interested in how it would handle asymmetric loads. How much before it tips into a cats cradle of wire? Is there any feedback into the system to detect such situations?

Reading a bit too literally and presuming the worst intent behind the statement. It leads to better discussions when people assume the best possible intent unless the person later clarifies their intent. I don't think they meant "model" as in "attractive fashion model".

"Standard model" is a thing among products. For example, they give out 3D glasses at the movie theater I visit. One-size-fits-all is the "standard model" but they have two sizes of booster seats. They have the "children model" and the "adult model".

So let's throw the complete statement that you removed back in:

>but what does this look like with ten fat disney tourists?

So the standard model ("little girl" [sic] sized) works great. How does the "jumbo model" work for an obese population?

I'll agree with the implicit sexism and infantilization behind the use of "little girl". Though I also refuse to ascribe sexist intent behind the word choice and I'm someone who cares about intent and not interpretation. One can always interpret the worst possible intent and find evil in everyone and every statement. Also yes, I'm aware that bad deeds can sometimes have good intentions.

They were highlighting a physical trait (smallness). "Small woman" and "little woman" are awkward to say and imply dwarfism. "Woman" as a standalone fails to highlight the smallness. I'd personally use "petite woman" but that becomes awkward in conversation because I'm seemingly the only person who uses the word "petite" in adult context without referring to porn actresses or nude models.

TL;DR:

It works fine for the 105 lb~ model. How about the 350~ lb model?