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]
Continue reading “Open Source Haptics Kit Aims to Democratize Force Feedback”
In June of 2014, [Afrdt] spent two weeks on a boat as an artist-in-residence in Linz, Austria. During that time, she created a dress that detects EMF waves and outputs them to vibration motors and a headphone jack.
[Afrdt] started by making two EMF coil antennas and sewed them to cuffs that snap together. She crafted fashionable fabric stripes that both conceal and carry the cables from the coils to an Adafruit FLORA that’s sewn into the body of the dress. The wearer experiences haptic feedback via vibration motors in the chest, and sonic feedback from a mini female headphone jack built into the collar. The zipper functions as a low-pass filter and volume control for the jack. One side bears resistive tape and runs to the FLORA, which is programmed to play an 800Hz tone. The other side runs to the headphone jack via conductive thread. As the zipper is opened, the pitch increases to toward the maximum pitch of 880Hz.
She drew inspiration for this project from [Aaron Alai]’s EMF detector project and built the code on top of it. Broader documentation and many more pictures are available both at [Afrdt]’s site and the residency program’s site.
This project is an official entry to The Hackaday Prize that sadly didn’t make the quarterfinal selection. It’s still a great project, and worthy of a Hackaday post on its own.
For his entry to The Hackady Prize, [Sean] is building a haptic vest for gamers and the visually impaired. It’s exactly what you think it is: a vest with proximity sensors and motors that wrap around the wearer, providing haptic feedback of nearby obstacles. Actually building a vest with a few dozen motors is a bit of a challenge, and that’s why this project is in the running for The Hackaday Prize.
Each of the 48 motors are individually controllable with PWM. In any other project, this would require a few dozen microcontrollers or one with a whole lot of pins. [Sean], however, is using LED drivers. They do exactly what [Sean] needs them to do – an easy to interface way of a whole bunch of PWM lines – and they do it cheaper than any other solution.
For detecting objects surrounding the vest, [Sean] is using the depth sensor on a 1st gen Microsoft Kinect. In testing, [Sean] blindfolded a volunteer and had a few friends move around with cardboard ‘obstacles.’ The volunteer successfully avoided all the obstacles, as seen in the video below.
The project featured in this post is a quarterfinalist in The Hackaday Prize.
Continue reading “THP Semifinalist: A Haptic Vest With 48 Vibration Motors”
The people at Two Bit Circus are at it again; this time with a futuristic racing simulator where the user controls the experience. It was developed by [Brent Bushnell] and [Eric Gradman] along with a handful of engineers and designers in Los Angeles, California. The immersive gaming chair utilized an actual racing seat in the design, and foot petals were added to give the driver more of a feeling like they were actually in a real race. Cooling fans were placed on top for haptic feedback and a Microsoft Kinect was integrated into the system as well to detect hand gestures that would control what was placed on the various screens.
The team completed the project within in thirty days during a challenge from Best Buy who wanted to see if they could create the future of viewing experiences. Problems surfaced throughout the time frame though creating obstacles surrounding the video cards, monitors, and shipping dates. They got it done and are looking towards integrating their work into restaurants like Dave & Buster’s and other facilities like arcades and bars (at least that’s the rumor going around town). The 5 part mini-series that was produced around this device can be seen after the break:
Continue reading “Custom Racing Chair with a Kinect and Haptic Feedback”
[AlexPewPew] tipped us off on some interesting virtual reality work going on at the Swiss Federal Institute of Technology in Zurich. Mapping a user’s head movement to match the images shown in a head mounted display is something the Oculus Rift is very good at. But in order to walk and move around freely in that virtual environment requires completely different hardware. We’ve seen some ingenious setups before, but nothing as efficient as this.
In the video above, they have put sheets of bar-coded paper on the ceiling in a grid pattern. A camera that mounts on the users head looks up at the grid of papers and gets the user’s location. The neatest part though, is how they are fitting a large virtual space into a small room. As the user walks down a straight virtual path, software is slowly making the actual path in the small room curve. The end result is the user walks in circles in the small room, thinking he or she is exploring a much larger space. Neat stuff!
If you have a head mounted display lying around, and can’t think of anything to enter into The Hackaday Prize contest, this would be a great concept to work on. What are you waiting for…get hacking!
Thanks to [AlexPewPew] for the tip!
The most common way to put some sort of haptic feedback in an interface hasn’t changed much since the plug-in rumble pack for the Nintendo 64 controller – just put a pager motor in there and set it spinning when the user needs to feel something. This method takes a relatively long time to spin up, and even the very cool Steam controller with voice coiled directional pads can’t ‘stick’, or stay high or low to notify the user of something.
[Tim]’s day job is working with very fancy piezoelectric actuators, and when an opportunity came up to visit the Haptics symposium, he jumped at the chance to turn these actuators into some sort of interface. He ended up creating two devices: a two-piezo cellphone-sized device, and a mouse with a left click button that raises and lowers in response to the color of the mousepad.
The cellphone device contains two piezo actuators with a 10 gram weight epoxied on. A small microcontroller and piezo driver give this pseudo phone the smoothest vibrations functions you can imagine. The much more innovative color-sensing mouse has a single actuator glued to the left button, and a photosensor in the base. When the mouse rolls over a dark square on a piece of paper, the button raises. Rolling over a lighter area, the button lowers. It’s all very, very cool tech and something we’ll probably see from Apple, Microsoft, or Sony in a few years.
Videos of both devices below.
Continue reading “Piezos For Haptic Feedback”
By now you should be familiar with MAME arcade cabinets and their ability to emulate any classic arcade machine from the days of yore. PinMAME is a similar setup to reconstruct classic pinball machines on computer monitors, but its popularity is nothing compared to the machines that play everything from Galaga to The Simpson’s arcade game. We won’t speculate on the reasons for that, but we do know how to make pinball emulation awesome – you need to emulate the buzzing and 60 Hz hum of solenoids found in the original machines.
This project comes from [Brendan Schrader] of the Hive76 hackerspace in Philly. It gives emulated pinball machines the tactile and haptic feedback required for a proper PinMAME setup. Inside [Brendan]’s box are two monitors, one for the backglass and one for the playfield, and a small computer to run the PinMAME software.
Also in the box are a few transducers usually used to turn any flat solid surface into a speaker. [Brendan] sent the audio output from the pinball emulation to a set of speakers and the ‘mechanical sounds’ audio to the transducer mounted to the chassis. The difference between haptic feedback and no haptic feedback is amazing, and something every PinMAME setup desperately needs.
Unfortunately, [Brendan] says he lives a decade in the past and doesn’t do the whole interwebs and email thing. He tells us he’ll send in a build log in a week or so, and we’ll put that up when it comes in.
Continue reading “How to make PinMAME awesome”