VR Gloves (my project)

Thanks for your thorough explanation!
I have next to zero knowledge of sensors, so everything is new to me.

If I understand correctly, the position of the shoulder is fixed. You get the elbow orientation from accel and gyro data, then, together with the upper arm length, you compute the elbow position (relative to the shoulder).
The elbow potentiometer gives the elbow angle that, along with elbow position and orientation and forearm length, allows to compute the wrist position.
Finally, accel + gyro from the wrist gives the hand orientation and the sensors on the fingers give finger bends.

It's quite different from what I thought, but it makes more sense now (hoping I finally got it) :)

That is exactly right. The shoulder does move some in relation to the chest, but I haven't thought of a way besides adding yet another sensor to the shoulder, but at this point I don't think it's really needed. At least in the case of the proof of concept or prototype one. It would eventually have to be there for full tracking of the chest itself though, as it feels weird to lean forward to try to grab something only to realize you aren't actually leaning forward. Kind of the same effect as when you lean forward with the rift.

At this point though, my glove is meant more as an extension rather then a full stand alone device. I may go the way of two devices, one that's just the glove and that's it, to be used with stem/priovr, which would lower the price by at least $10-15 and make it easier to integrate into a game, and then one that tracks the arms and chest for limited positional tracking.

As stated in the update section of my post, I am getting in the potientiometers that I need to try to replace the flex sensors. I've barely used the sensors, and it already looks like they are starting to wear down, so they don't seem like a good long term solution. (the white silkscreen is almost rubbing off in some parts) They (flex sensors) are also pretty expensive at around $13 a pop, so if I can get the pots to work like I expect, it'd be $15 per glove instead of the flex sensors $52, so it substantially lowers the cost. In materials, it'd be around $40-50 per glove in the end. (these are all estimates of course, and shouldn't be considered fact)

I have another 10 days wait to see if I get through the first round of the arch grants ($50k investment without giving equity {angel investment}, as well as mentoring and things of that sort) If I get through the first round to where I actually start to show it off, I'm fairly certain I would win at least the basic tier. (There are 2 $100k winners this year out of the 20 or so they would normally give the grant to)

I'm rambling about this stuff again. -_- Sorry about that. Just excited. Anyway, my point in mentioning the arch grants is simply to state my plans if it doesn't go through. I'll either put it on kickstarter, or make it open source hardware (probably kickstarter, and if that fails, then definitely open sourcing it)

The reasons it's likely to fail in any of the mentioned ways to get it funded is the same reason VR is having trouble. People don't have the device, so it's hard to convince game companies to make games that interface with it. Valve is pretty much the only company that seems to be interested enough in just vr to make games specifically with vr in mind, so getting companies to support something that not only requires vr, but also a subset technology will be even harder. I do thing that things like VR will take off, and if it does, and things like my glove and the omni work together, it could create a very very immersive experience.

(Sorry for another randomly long post that doesn't really talk about the original topic much XD Just the way my brain went)

I hope the potentiometers will work the way you expect!
Again, congratulations for your work and good luck for the arch grant - should that fail, I would surely back your glove on kickstarter :)

Thanks, and "should" know on the arch grant thing in a little over a week... unless they delay it again. (Original date for saying if you got through the first round was on feb 10th, but they delayed it a month for some reason. Probably a lot more entries then expected and wanted proper time to review them all)

Interesting project, wish that there was a decent product like this on the market already... Cause I need one for my bachelor thesis haha :) But sadly it seems I need to go with something quick and shabby like the wiimote or create my own glove.

"danishdragon" wrote:
Interesting project, wish that there was a decent product like this on the market already... Cause I need one for my bachelor thesis haha :) But sadly it seems I need to go with something quick and shabby like the wiimote or create my own glove.

I had this exact same problem. There wasn't anything on the market, so I had to hack together a pair of VR gloves from some gutted Hydras and bend sensors/teensy3.0 boards. I managed to go through 2 pairs of hydras until the system was stable.

@CaliberMengsk: I know these quotes of yours below are a few months old (December 2013), but I still feel they need some commenting. You said:

"CaliberMengsk" wrote:
Stem is just motion tracking. It tells angle (accelerometer) and applied force (gyro). I'm sure I'm over simplifying it, but the point is, stem doesn't have the extra bits, finger tracking being the main thing.

[...]

The problem with using magnets is mostly range and accuracy without interference. I haven't messed a lot with magnets and electronics, but magnets can only give you a distance, not really direction.

[...]

I also know that the tech for stem is not nearly that expensive, especially when bought in bulk like they are definitely doing. You can get an accellerometer off of mouser.com for $0.56 if you buy 1000 or more, and I can promise you that sixense is not only buying more then that, but probably has insider deals to get it cheaper.

Actually, STEM (like also the Hydra) uses a totally different technological approach than accelerometers, gyros and magnetometers: They create an A/C electromagnetic field in their base station which is picked up in the sensor modules for very accurate, absolute positional tracking. This totally eliminates drift, and gives you a precise position and orientation in 3D space within the range of the sensors. That also explains the price: Instead of using standard, cheap industry components like accelerometers or gyros (or combined IMUs) they developed their own electromagnetic field tracking system.

Having said this: I've been following your project for a while now, and always wondered why you would need the elbow and shoulder flex sensors. With an accurate positional tracking of the hand itself, shouldn't it be possible to use just software (inverse kinematics) for determining the position and orientation of the forearm and upper arm? Or, as an alternative: Track the position/orientation of the forearm (like at the wrist), and then use an additional (bi-directional) flex sensor at the wrist to determine the position of the hand relative to the forearm. Maybe a VR glove can be also be conceived to be an accessory to STEM, so no need to care about positional tracking at all?

Just my thoughts... I'm also working on a similar project since a while now, but concentrating more on the haptic feedback part. I'll post more info about it once it's matured enough.

@gstercken: At that time, there wasn't a ton of information on stem, and I didn't read a ton into it. I didn't know at the time that it was using a magnetic base like the hydra. More then likely I could get a similar system working with just adding in a magnetometer and an electromagnetic base to get a similar effect. They probably use much more sensitive magnetometers then I would have due to my trying to keep price down.

You are right that for the most part, I could probably get the entire system working without the arm and just use inverse kinematics. Personally though, while you can get a decent representation of arm position and such, it's just nicer to add in the extra bits to make it be more exact. IK is ok, but if for example you just move your hand towards your chest, then the IK could randomly make the elbow go straight up instead of to the side or down. Obviously this wouldn't look right. This is also why the people making PrioVR have two trackers on the arms.

PrioVR actually failed originally. The current kickstarter isn't their first attempt. This is probably due to the fact that their first one was around the same time as stem. But they also made a few additions. Biggest one being a tracker for the hand/wrist being bent, and a trigger. (It didn't have that, so it looked odd in game) So in that sense, my glove may not be needed for most people. But, I'd like to have each finger being tracked, and I'd also like to not have a magnetic base if avoidable... I'd also like to obviously keep the price down.

All that said, if PrioVR and Stem (which I think priovr will be more popular then stem personally.) do well enough, I could probably just break my glove into finger tracking and use them as the main system, or make the elbow/arm tracking optional just like priovr is doing with it's leg tracking.

That all said, I'm wondering how cheap I could make a full motion tracking system like theirs, using a similar system as my arm tracking.

I broke my wrist and leg back in January and am still recovering from that. I mention this because my experience has caused me to re-evaluate a lot of things. It also made me think of suggesting that you consult a physical therapist or similarly qualified medical professional about the different ranges of motion both normal and injured/disabled individuals might have. This information could be particularly useful in the drivers for your gloves. What may be physically impossible motion for you, could be perfectly normal for someone else and vice versa. It's most likely that your gloves will require calibration in order to function correctly for different individuals. It would be unfortunate if that calibration failed to consider the potential for abnormal ranges of motion.

Also, it brings to mind the importance of possibly remapping functions or gestures for people who are incapable of certain motions. For example, I currently have a great deal of difficulty touching my thumb to my pinky. If there was someone incapable of doing that for some reason and you had that mapped to an important function, they would need to either create a custom gesture or remap the function to something else.

Well, this is probably something that's not terribly important right now. It's just been my experience that, when you're developing software, failing to consider how the final product will function can cause the need to do a full re-write just to add critical functionality that had been overlooked. Even when you plan well, there's always the potential need for a complete re-write when it comes to software. It's just that the more you plan things out now, the less you'll have to do down the road.

What you say about these gloves? accuracy... technology...









p.s. Good luck with your project !