34 karma · joined November 5, 2022
Can’t at 10 Hz.
It is the usual stuff.
Check out the work of Vincent Hayward on cantilevers and piezo.
I was not able to locate the frequency response profile of the actuator, which is what really counts.
Rapid moving sensations are really not an issue in todays market.
I hope one day someone comes up with something there which does not requires a backpack of pumps like Haptx.
That moment is when magic will happens in haptics
Perceptual modes are specific mechanical stimuli we learned to recognize as specific sensations.
Some of them are: stiffness which is skin indentation and tendons strain in function of space, vibrations which is skin indentation in function of time for frequency above 10/20 hz.
These modes resides a bit on the neurophysiology of touch (how mechanoreceptors respond) and a bit on how we learned to recognize touch sensations.
The problem reside that the first thing you want to do is manipulate, not simply touch.
Manipulation is a bitch because it mostly needs small indentation of the skin which are 1-3 mm of continuous displacement at 1 mm resolution under the fingertip.
They piezo they are using displaces 1 mm at the resonance frequency, I imagine 150 hz (I believe?) or something similar, not in continuous (again, I believe).
Which means that a contact on the sensor is rendered as a local vibration, which requires a lot of mental gymnastic to think of it as a contact.
That is the haptic metaphor. Basically you expect an indentation and you get a vibration, and this sucks and for users.
If they got it in static displacement that is cool and might be something noteworthy
The patches are vibrating, but humans perceive static and low frequency forces mostly.
This create a haptic metaphor which always sucks.
The rest is easy, or easy to figure out.
Never heard telehaptics as term in my whole life
I wrote few of these algorithms myself for some other products.
There is always a trade off between fidelity and immersive feeling because the basses were not meant to be used with such product in mind.
With my company, Interhaptics, we built a full stack pipeline only for haptics. Our tech is at the basis of the MPEG haptics encoding standard coming out shortly.
We have been recently acquired by Razer, look out for news of you are interested to build for touch natively
For the buttkicker the real issue is the chair itself. It filters a ton of stuff and rattles.
A good experience are the Dbox chairs, the problem is that they cost 5 k.
Relevant club podcast with the CTO https://open.spotify.com/episode/6ERkgfJxm7QCZlp1p5eIGD?si=E...
If he is looking to get the bass feeling of the music you want the pure input.
The key is to mount them properly on the body to maximize mechanical coupling. You don’t need a lot of watts if the losses are almost zero.
If you want more, build an array of actuators and spread them out.
More immersive feeling compared to a stronger one.
Get a well know console controller, take out the two actuators and mount them in any other form factors you like.
You can drive them with an audio pipeline, they are effectively a 4 ohm speaker. Attach them to a sound card and you can have your stereo haptics subwoofers.
You have to filter out aggressively the resonance frequency of the actuator to get a flattish response. Not that subpac or the other folks do so
The way around the seat shaking problem is to use wideband vibrotactile actuators tuned to respond between 10 and 250 Hz on different part of the body. They can be embedded is seat or on a vest.
The mechanical energy transfer is local, can be tuned individually, and consumes much less energy.
There are also several successful products leveraging this principle like the Razer Hypersense line, feel belt, and others.
A recent company acquired by Meta, Lofelt, started their tech doing exactly this.
If you want to jump into the haptics rabbit hole, I animate a podcast [0] with some industry folks. Fascinating topics.
[0]: www.thehapticsclub.com