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.
The worst thing about walking around while trying to follow directions is that you have to keep looking down at them to get the next turn. At best, you’ll miss out on the scenery; at worst, you might walk into traffic.
Wouldn’t it be great if you didn’t have to look down? Yes it would, and with Walkity, there’s no need to look down. Walkity is a set of cuffs that slip on the backs of your shoes, pairs with your phone, and uses haptic feedback to tell you where to go. Each one has an Arduino Mini Pro, an NRF24L01 to talk to its mate, a Bluetooth module, a vibration motor, and what must be the thinnest, most flexible LiPo currently available on Earth. The specified cell is PGEB0083559, a 65 mAH cell that is 0.8 mm thick!
Your smartphone will vibrate in your pocket during naviation but our experience has been that of still not knowing which way to turn. Walkity’s feedback is simple and intuitive. The left cuff vibrates to indicate a left turn, right for right, and both vibrate when you reach your destination. Going the wrong way? Walkity will vibrate vigorously to let you know it’s time to pull over. It’s a great example of a an entry for the Human Computer Interface Challenge of the Hackaday Prize!
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.
We have seen a few of these types of devices in the past, and they almost always use ultrasonic sensors to gauge distance. Not so with this ETA; it uses six VL53L0X time-of-flight (ToF) sensors mounted at slightly different angles from each other, which provides a wide sensing map. It is capable of detecting objects in a one-meter-wide swath at a range of one meter from the sensors.
The device consists of two parts, a wayfinding wand and a feedback module. The six ToF sensors are strapped across the end of a flashlight body and wired to an Arduino Mini inside the body. The Mini receives the sensor data over UART and sends it to the requisite PIC32, which is attached to a sleeve on the user’s forearm. The PIC decodes these UART signals into PWM and lights up six corresponding vibrating disc motors that dangle from the sleeve and form a sensory cuff bracelet around the upper forearm.
We like the use of ToF over ultrasonic for wayfinding. Whether ToF is faster or not, the footprint is much smaller, so its more practical for discreet assistive wearables. Plus, you know, lasers. You can see how well it works in the demo video after the break.
If you are blind or your vision is impaired, moving around in a new space can be a harrowing experience. A cane helps, but only samples one point at a time, and can’t help that much above a certain height. The Digital White Cane is a haptic feedback device that uses Time of Flight components to detect surrounding objects.
The Digital White Cane uses a type of LIDAR known as Time of Flight (ToF) sensing. Rather than a point by point scan by a laser, ToF sensors capture an entire scene with each pulse. These sensors are actually somewhat new and designed for the latest generation of robotics and hand detection for soap dispensers. The good news is that they’re small and cheap, just what you want for a wearable.
The sensors allow detection of objects within 2m (about 6 feet) from all directions. Haptic feedback allows the wearer to determine where the object is around the wearer. Because it’s head-mounted, it detects objects at head height as well as floor height. A Teensy LC is used as the main processor and is connected to the ToF sensors as well as small motor board for the haptic feedback.
This project has a lot of potential to help people with vision impairment and is a great entry into the 2017 Hackaday Prize. Check out the video after the break to see it in action. If you’re looking for some more applications of this small, cheap ToF sensor, check out this cat food dispenser, and here’s a ball-balancing robot – both pretty cool projects in their own right.
The World Health Organization estimates that around 90% of the 285 million or so visually impaired people worldwide live in low-income situations with little or no access to assistive technology. For his Hackaday Prize entry, [Tiendo] has created a simple and easily reproducible way-finding device for people with reduced vision: a bracelet that detects nearby objects and alerts the wearer to them.
It does its job using an ultrasonic distance sensor and an Arduino Pro Mini. The bracelet has two feedback modes: audio and haptic. In audio mode, the bracelet will begin to beep when an object is within 2.5 meters. And it behaves the way you’d expect—get closer to the object and the beeping increases; back away and it decreases. Haptic mode involves two tiny vibrating disk motors attached to small PVC cuffs that fit on the thumb and pinky. These motors will buzz differently based on the person’s proximity to a given object. If an object is 1 to 2.5 meters away, the pinky motor will vibrate. Closer than that, and it switches over to the thumb motor.
To add to the thriftiness of this project, [Tiendo] re-used other objects where he could. The base of the bracelet is a cuff made from PVC. The nylon chin strap and plastic buckle from a broken bike helmet make it adjustable to fit any wrist. To keep the PVC cuff from chafing, he slipped small pieces from an old pair of socks on to the sides.
It’s easy to see why this project is a finalist in our Best Product contest. It’s a simple, low-cost assistive device made from readily available and recycled materials, and it can be built by anyone who knows a little bit about electronics. Add in the fact that it’s lightweight and frees up both hands, and you have a great product that can help a lot of people. Watch it beep and buzz after the break. Continue reading “Hackaday Prize Entry: A Bracelet for the Blind”→
Chorded keysets can be found all over. For instance, Braille writers and court stenographers both use them. These chorded keyboards create each letter by pressing a combination of keys rather just one, making for much smaller keyboards [Christine] got the idea to create wearable rig that uses an accelerometer and vibe motor attached to each finger to serve as a one-handed, no-look, silent keyer. Forget small keyboards, this project does away with it altogether, relying on the accelerometers to keep track of your fingers.
[Christine]’s prototype consists of a Bluno BLE controller, a GSM module, and a few accelerometers and motors. The vibration motors not only provide haptic feedback so you know you tapped something, but also replays the chords so you can double-check what you’re writing.
Typically one-handed keyboards rely on button presses, with no-look use dependent on memorizing the layout—think of a 10-key pad. [Christine]’s project lets you type on any surface or none at all, making it handy for typing while you work with the other hand. It also has great potential for vision impaired users.