In Pursuit Of Haptics For A Better VR Experience

February 12, 2020 by Mike Szczys 6 Comments

Virtual reality holds the promise of an immersive experience that can satisfy our senses to a level comparable with… well, reality. The field has come a long way, but Sarah Vollmer makes a good point that many of the VR systems currently in use are bulky and difficult to transfer from person to person.

While headsets have become smaller and lighter and now feature improved motion tracking and resolution, their ability to affect the user’s other senses hasn’t seen nearly the same advancement. Haptic feedback systems need to catch up with headsets, and how to unobtrusively allow users feel simulated physical contact in VR is an area Sarah is researching as part of her PhD work. This is the topic of her 2019 Hackaday Superconference talk which you’ll find embedded below.

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Giving Sight To The Blind With A Wave Of The Hand

November 6, 2019 by Gerrit Coetzee 1 Comment

[Jakob Kilian] is working on a glove that he hopes will let the blind “see” their surroundings.

One of the most fascinating examples of the human brain’s plasticity is in its ability to map one sense to another. Some people, for example, report being able to see sound, giving them a supernatural ability to distinguish tones. This effect has also been observed in the visually impaired. There are experiments where grids of electrodes were placed on the tongue or mechanical actuators were placed on the lower back. The signals from a camera were fed into these grids and translated in to shocks or movement. The interesting effect is that the users quickly learned to distinguish objects from this low resolution input. As they continued to use these devices they actually reported seeing the objects as their visual centers took over interpreting this input.

Most of these projects are quite bulky and the usual mess you’d expect from a university laboratory. [Jakob]’s project appears to trend to a much more user-friendly product. A grid of haptics are placed on the back of the user’s hand along with a depth camera. Not only is it somewhat unobtrusive, the back of the hand is very sensitive to touch and the camera is in a prime position to be positioned for a look around the world.

[Jakob] admits that, as an interaction designer, his hardware hacking skills are still growing. To us, the polish and thought that went into this is already quite impressive, so it’s no wonder he’s one of the Hackaday Prize Finalists.

Wind-Blaster: Haptic Feedback That’ll Make You Recoil

September 16, 2018 by Steven Dufresne 8 Comments

A big challenge in the VR world is getting haptic feedback no matter where you are. That’s not so much of a problem when you’re sitting in a chair, the hardware can be attached to the chair or to something near you, what’s referred to as grounded force-feedback. But with VR, we’ve gotten used to at least moving around a room. How then do you feel the recoil of a gun, the pressure against a shield, the inertia of a sword slicing through the air, or the pulsations of magic sword emitting lightning?

A team of researchers at the [MAKinteract Lab] at KAIST, a university in South Korea, have come up with a small device which straps to your wrist and provides all those types of feedback. It’s called the Wind-Blaster and consists of two ducted propellers which can provide up to 1.5N of force. Both propellers are mounted on servos, and with the help of an IMU, the propellers are oriented as needed. An Arduino doing PWM controls the motor speeds.

Fire a VR shotgun and the propellers quickly spin up to 33,000 RPM for just 250 ms, giving your lower arm a quick backward tug, providing the feel of a recoiling gun. Swing a VR sword through the air and the propellers rotate at 33,000 RPM for 400 ms and then linearly decelerate to a stop in 300 ms. Making the propellers move asynchronously with respect to each other causes rotation torque on your arm for a pulsating feeling for the magic lightning-emitting sword. A connected PC runs the games using the Unity game engine. As with drones, there is noise at around 41 dB but the user’s headphones block it out. Watch it in action in the videos below.

Here on Hackaday, we’ve covered few more ungrounded haptic feedback systems. There’s one which responds to light, another which lets you feel textures, and a glove which gets feedback as it controls a robotic gripper.

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Friday Hack Chat: Training Robots By Touch

August 1, 2018 by Brian Benchoff 3 Comments

When it comes to training robots, you could grab a joystick or carefully program movements in code. The better way, though, is to move the robot yourself, and have the robot play back all those movements ad infinitum. This is training robots by touch, and it’s the subject of this week’s Hack Chat over on hackaday.io.

Our guest for this week’s Hack Chat will be [Kent Gilson], inventor, serial entrepreneur, and pioneer in reconfigurable computing. [Kent] is the creator of Viva, an object-oriented programming language and operating environment that harnesses the power of FPGAs into general-purpose computing He’s launched eight entrepreneurial ventures, won multiple awards, and created products used in numerous industries across the globe.

[Kent]’s claim to fame on hackaday.io is Dexter, a low-cost robotic arm with 50-micron repeatability and modular end effectors. It does this with three harmonic drives and optical encoders that give it extreme precision. The arm is also trainable, meaning that you can manually control it and play back the exact path it took. It’s training robots by touch, exactly what this Hack Chat is all about.

For this Hack Chat, we’re going to be discussing:

Building trainable robots
Developing robotics haptics
Training robots to manufacture
Heterogenous direct digital manufacturing

You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the Hack Chat Event Page and we’ll put that in the queue for the Hack Chat discussion.

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This week is just like any other, and we’ll be gathering ’round our video terminals at noon, Pacific, on Friday, July 27th. Need a countdown timer? Well, here you go, mango.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

What We Need To Try In Haptic Hacks

March 22, 2018 by Steven Dufresne 9 Comments

Looking for ideas for your haptics projects? [Destin] of the Smarter Every Day YouTube channel got a tour from the engineers at HaptX of their full-featured VR glove with amazing haptic feedback both with a very fine, 120-point sense of touch, force feedback for each finger, temperature, and motion tracking.

In hacks, we usually stimulate the sense of touch by vibrating something against the skin. With this glove, they use pneumatics to press against the skin. A single fingertip has multiple roughly 1/8 inch air bladders in contact with it. Each bladder is separately pneumatically controlled by pushing air into it. The air pressure can vary continuously so that the bladders can push lightly, harder or anywhere in between. The glove has 120 of these bladders spread out over the fingers and the palm. Unfortunately, they didn’t allow him to see the valves controlling the pneumatics, but if you are looking for a low-frequency, low-cost way to actuate valves you might consider using syringes. The engineers do tell [Destin] that if your VR scene shows something pressing against your virtual finger, as long as your haptics push against your real finger within around 1/8th of a second, your brain won’t notice the delay.

They’re also working on using hot and cold fluids to give a sense of temperature within a glove. This is demonstrated in the first video below when [Destin] feels heat while a dragon in the VR world breathes fire on his hand. Fortunately one of the engineers mentions that our sense of temperature is one of the slower ones, it can handle longer latencies than even touch. We can see implementing this in a hack using a bladder pressing against the skin while tubes circulate different temperature fluids through it. But maybe there’s a way to do it electrically, possibly with thermoelectric modules as is done with this drinks cooler? Though safety issues might prohibit that.

Other features mentioned are force feedback for each finger, and their custom motion tracking which uses both magnetic and optical means to track fingertips. But we’ll leave the rest to the videos below. The first is the technical tour and the second is the glove being used in the VR world.

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Neil Movva: Adding (wearable) Haptic Feedback To Your Project

December 22, 2015 by Adam Fabio 4 Comments

[Neil Movva] is not your average college student. Rather than studying for exams or preparing to defend a dissertation, he’s working on a project that will directly help the disabled. The project is Pathfinder, a wearable haptic navigation system for the blind. Pathfinder is an ambitious project, making it all the way to the semifinals of the 2015 Hackaday Prize. Haptics, the technology of providing feedback to a user through touch, lies at the core of Pathfinder. [Neil] was kind enough to present this talk about it at the Hackaday SuperConference.

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Open Source Haptics Kit Aims To Democratize Force Feedback

January 21, 2015 by Sonya Vasquez 27 Comments

If you’ve been keeping up with augmented and virtual reality news, you’ll remember that spacial haptic feedback devices aren’t groundbreaking new technology. You’ll also remember, however, that a professional system is notoriously expensive–on the order of several thousand dollars. Grad students [Jonas], [Michael], and [Jordi] and their professor [Eva-Lotta] form the design team aiming to bridge that hefty price gap by providing you with a design that you can build at home.

A quick terminology dive: a spacial haptic device is a physical manipulator that enables exploration of a virtual space through force feedback. A user grips the “manipulandum” (the handle) and moves it within the work area defined by the physical design of the device. Spacial Haptic Devices have been around for years and serve as excellent tools for telling their users (surgeons) what something (tumor) “feels like.”

In our case, this haptic device is a two-link, two-joint system grounded on a base station and providing force feedback with servo motors and tensioned wire ropes. The manipulator itself supports 3-degree-of-freedom movement of the end-effector (translations, but no rotations) which is tracked with encoders placed on all joints. To enable feedback, joints are engaged with cable-drive transmissions.

The design team isn’t new to iterative prototyping. Hailing from CS235, a Stanford course aimed to impart protoyping techniques to otherwise non-tinkerers, the designers have drawn numerous techniques from this course to deliver a fully functional and reproducible setup. In fact, it’s clear that the designers have a strong understanding of their system’s physics, and they capitalize on a few tricks that don’t immediately jump out to us as intuitive. For instance, rather than rigidly fixing their cable to the motor shaft, they simply wrap the cable around the shaft a mere 5 turns such that the force of friction greatly exceeds the threshold amount that would otherwise cause slipping. They also choose plywood–not necessarily because of its price–but more so because of its function as a stiff, layered composite that makes it ideal “lever arm material” for rigidly transferring forces.

For a full breakdown of their design, take a look at their conference paper (PDF) where they evaluate their design techniques and outline the forward kinematics. They’ve also provided a staggeringly comprehensive bill of materials (Google Spreadsheet). Finally, as justifiably open source hardware, they’ve packaged their control software and CAD models into a github repository so that you too can jump into the world of quality force feedback simulation without shelling out the twenty thousand dollars for a professional system.

[via the 2015 Tangible Embedded and Embodied Conference]

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