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Cable Robot Simulator [video]

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Re: Cable Robot Simulator [video]

#51

Post by Nadya »

hn9780470248775 wrote: post #43
sandworm101 wrote: post #42

All well and good with the standard little girl model, but what does this look like with ten fat disney tourists? What would the machinery look like to swing 10 or 50 times the weight? (Same question if this is to be used for flight simulators.) Is there a point at which linear hydraulic actuators are easier?

> All well and good with the standard little girl model "The software developer Maria Lächele from the 8-person developers team at the Max-Planck Institute is seen amongst others as a passenger of the robot."

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?

Re: Cable Robot Simulator [video]

#52

Post by jameshart »

sllabres wrote: post #26
jameshart wrote: post #5

This seems like a poor fit for VR motion simulation - actual movement through space is generally unnecessary, you just need to gimbal the platform to simulate accelerations. Actual linear acceleration is of limited value in simulation because you can't maintain that acceleration indefinitely - you run out of room and have to apply an opposite acceleration, which can conflict with the simulation needs. On the other ha…

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

For flight, the problem is that the only acceleration that really matters is variation in vertical acceleration. Linear acceleration can briefly simulate that, but it can't be sustained. That's a fundamental problem that can only be dealt with by creating that kind of massive vertical acceleration environment - even that will be limited in terms of how long it can simulate sustained > or < 1g. You can create sustained accelerations by spinning something round on the end of an arm, but there's always that pesky downward gravity vector that keeps getting added to everything, unless you build your simulator in orbit.

Re: Cable Robot Simulator [video]

#53

Post by sandworm101 »

hn9780470248775 wrote: post #43
sandworm101 wrote: post #42

All well and good with the standard little girl model, but what does this look like with ten fat disney tourists? What would the machinery look like to swing 10 or 50 times the weight? (Same question if this is to be used for flight simulators.) Is there a point at which linear hydraulic actuators are easier?

> All well and good with the standard little girl model "The software developer Maria Lächele from the 8-person developers team at the Max-Planck Institute is seen amongst others as a passenger of the robot."

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?

Re: Cable Robot Simulator [video]

#54

Post by patcon »

jimm wrote: post #48
ljk wrote: post #39

Earlier quoted context omitted.

> Rather, you make a linear movement, and THEN you rotate the simulator (if you need to sustain the acceleration). Am I understanding this wrong or are you saying long accelerations can be achieved by accelerating, turn, accelerating, .... etc? Wouldn't the person wearing VR headset feel the turn?

Let's say I want to simulate acceleration going forward. First, there's the burst of forward motion provided by the cable rig, and that can be > 1G. By also gradually flipping the person onto their back you can simulate continued acceleration of 1G because lying on your back feels the same as 1G of acceleration forward. The VR rig would still show you accelerating forward. I am guessing that if the rig also slowly mo…

This is really neat! I'm really curious what the motion would look like from outside the room, and what the limits of a simulation would be using this technique...

It seems like the sort of fun project that would be cool to simulate in a graphic engine -- pairing the playing of certain games with a 3D model of the simulation room :)

Re: Cable Robot Simulator [video]

#55

Post by iridium127 »

ljk wrote: post #40
oskenso wrote: post #38

This could make for an interesting Disney ride!

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

with those same cables, they would probably be able to carry hundreds of people at the same time... just make the platform a bit bigger and maybe upgrade the winches.

Re: Cable Robot Simulator [video]

#56

Post by TrevorJ »

irl_zebra wrote: post #49
TrevorJ wrote: post #37

The concern I have is that failures in the control software or mechanical failure would have grave consequences. Maybe that's a solved problem and the cable capstans have mechanical arrestors that kick in, etc but the setup looks inherently unstable unless under active computer control (due largely to the crossed cable attach points). This is quite a bit different than a more typical hydraulic setup where an unpowere…

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…

It's more about how the cable is managed in terms of slack, keeping the cage from flipping over, etc. I agree with you, the cable itself is an unlikely point of failure.

Re: Cable Robot Simulator [video]

#57

Post by jbattle »

TrevorJ wrote: post #37

The concern I have is that failures in the control software or mechanical failure would have grave consequences. Maybe that's a solved problem and the cable capstans have mechanical arrestors that kick in, etc but the setup looks inherently unstable unless under active computer control (due largely to the crossed cable attach points). This is quite a bit different than a more typical hydraulic setup where an unpowere…

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

Re: Cable Robot Simulator [video]

#58

Post by laxatives »

jonknee wrote: post #46
TrevorJ wrote: post #37

The concern I have is that failures in the control software or mechanical failure would have grave consequences. Maybe that's a solved problem and the cable capstans have mechanical arrestors that kick in, etc but the setup looks inherently unstable unless under active computer control (due largely to the crossed cable attach points). This is quite a bit different than a more typical hydraulic setup where an unpowere…

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

There's certainly been instances of cameras coming down and having near misses with players and referees. Those cams weigh a lot and are moving at high speed as well.

edit: quick search returns https://www.youtube.com/watch?v=GPPJ6rg_TTA

Re: Cable Robot Simulator [video]

#59

Post by ljk »

jimm wrote: post #48
ljk wrote: post #39

Earlier quoted context omitted.

> Rather, you make a linear movement, and THEN you rotate the simulator (if you need to sustain the acceleration). Am I understanding this wrong or are you saying long accelerations can be achieved by accelerating, turn, accelerating, .... etc? Wouldn't the person wearing VR headset feel the turn?

Let's say I want to simulate acceleration going forward. First, there's the burst of forward motion provided by the cable rig, and that can be > 1G. By also gradually flipping the person onto their back you can simulate continued acceleration of 1G because lying on your back feels the same as 1G of acceleration forward. The VR rig would still show you accelerating forward. I am guessing that if the rig also slowly mo…

Thanks for explaining, I kind of understand it now, but what if the acceleration is > 2G, then gravity won't be enough to simulate it, and I'm still a little skeptical that the user won't feel the rotating and "slowly move back" to original position, but I've never used a VR headset so I might be completely wrong here

Re: Cable Robot Simulator [video]

#60

Post by joliv »

oskenso wrote: post #38

This could make for an interesting Disney ride!

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.

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