Holotron presents a lower-body VR exoskeleton with full force feedback
As quickly as our brains accept virtual reality once our vision and hearing are hijacked, there are plenty of people trying to extend the illusion across our other senses, moving towards a future of total physical immersion that replicates experiences across all our senses.
But it ain't an easy problem to solve. As we interact with the world, so the world interacts with us, and to truly feel like we're physically inhabiting a virtual world, or to accurately control a robotic telepresence somewhere else on the planet, the virtual world needs to be able to exert forces on the body even as we operate against it. When you punch a wall, your hand has to stop.
When you push against something, you need to feel the resistance. A VR exosuit needs to perfectly measure how much force you're exerting, while exerting an appropriate force in reverse – at any angle, on any part of the body. It's a hardware nightmare.
Leaving aside the billion-dollar holy grail of virtual sex you can actually feel, let's take a look at how one German company is trying to replicate the simple physical experience of walking with a force-feedback lower-body exoskeleton. Dr. Marcel Reese says he's prototyped the first working system for force feedback and balance feedback as you walk in VR.
The Holotron, as he calls it, starts out by suspending you off the floor, meaning it can decide where the floor is in the virtual world, and what angle, and how it's moving. It also lets you feel a certain facsimile of physical movement when you jump or get thrown into the air.
Your legs are placed into a beefy frame covered with motors and sensors, which Reese says operate in low latency to track your leg movements while delivering resistance and force motion where appropriate. If a big ball rolls into your leg, it'll knock your leg backwards. A set strength limit of 150 Nm represents 25 percent of the force the suit could exert on a user, and anything outside those limits will cause the body to go briefly out of sync with the virtual world until it catches up again.
Reese has been testing it at a simulated 1/20th of normal Earth gravity, making walking around and jumping less laborious than in real life while still giving a user a sense of force and balance. Currently, there are motors only at the hip and knee joints, but future plans would extend this to five motors on each leg, with more on your arms, hands and back.
Eventually, he hopes to replace that huge, cheap wooden frame with a floor-mounted multi-axis gimbal arrangement that would tidy up the chunky electronics of the prototype and add the ability to flip and spin users around in all directions... That'll be fun, simulating a full-body swimming, flying and somersaulting experience, and flinging you all over the place if you step on a land mine. Later upgrades, he says, will give "high-resolution tactile feedback for all body parts, thermal feedback, smell and taste." That sounds crazy ambitious to us, but then it does seem certain that VR will take over all our senses at some point in the future.
Reese has built and coded this prototype with just €55,000 (US$67,000) of funding, to the point where he and his collaborators have got it up and running with a few applications. One lets you climb stairs, one simulates being hit with a heavy ball, one lets you balance on a skateboard across rough terrain, one has you walking across a series of moving stones, another has you bouncing on a springy platform.
Now, to be sure, there's a certain QWOPpiness to the movement as shown in the video below – you bet I had a couple of cracks at that old classic getting you that link, can anyone beat 14.7 meters? But you can clearly see the machine turning the simulated motion of VR into a physical experience, giving as good as it gets from the user.
It's tempting to say this kind of thing won't be necessary, that VR and AR will enter mainstream life in far less intrusive ways. And they will; the Oculus Quest and Quest 2, for example, prove how effectively you can be immersed in a virtual world even with a small, lightweight, surprisingly cheap headset. Imagine how good portable VR will be in 10 or 20 years.
But at some point, people will want to get more of their bodies involved, and clunky early devices like the Holotron here, and other efforts from folks like AxonVR, Tesla Studios (no relation), Disney, Wireality and others, are paving the way for some pretty wild experiences most of us won't be feeling for decades.
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