Microsoft Research has returned with a new virtual reality (VR) haptic controller. Dubbed the Haptic PIVOT, this new device is the latest addition to Microsoft’s series of haptic controllers designed to create realistic physical sensations in VR. The PIVOT is responsible for object dynamics and is intended to further supplement the company’s haptic controller lineup in order to create a more accurate sensory interaction. This device wraps around the wrist and includes a haptic handle that pivots in and out of a user’s hand. Compared to existing handheld haptic devices and gloves, the PIVOT allows users to utilize their hands when the device isn’t needed.
The decision to design the PIVOT to fit on the wrist was completely intentional. This is because Microsoft wanted to simulate the natural contact of catching and holding an object in real life, which is something most handheld controllers don’t offer. By positioning the device on the wrist, the team was able to engineer the momentum and drag of thrown and caught objects through the haptic handle.
The hinge mechanism and the haptic handle are the core of the PIVOT’s design. The prototype haptic handle was outfitted with capacitive touch sensors capable of detecting the contact and release of an object. In addition to this, the device includes a voice coil actuator for vibrotactile feedback, as well as a trigger switch for control input. The hinge is powered by a servo motor modified specifically for the PIVOT. This allows the haptic handle to be grasped and released on demand. The motor automatically stops running once the capacitive sensors recognize that the handle is inside the palm. A passive radioulnar hinge also lets users freely move their wrists up to 60 degrees while holding the handle.
The device is also intuitive. This means a user can simply flick their wrist and the PIVOT will instantaneously rotate into their palm. Another flick and the handle also retracts. These movements are monitored by an internal accelerometer. The hinge is also designed to slant toward the hand with a 190-degree range to prevent it from obstructing when at rest.
The PIVOT is ideal when used for interacting with virtual objects. Computer-vision tracking through either a head-mounted display (such as the Microsoft HoloLens) or any other commercial VR tracker fitted to the back of the hand allows the control system to accurately detect when the user reaches for an object. When tested to pick apples in a virtual simulation, the haptic handle immediately prepares to move once the apple is within a 30-centimeter radius. When the device is within 10 centimeters, the handle begins to move closer and makes contact with the palm the moment the user touches the virtual fruit. The sensors then acknowledge the contact and sends a signal to the virtual hand.
The PIVOT also enhances the sensory experience using its other features. The voice coil actuator creates a “thud” sensation when the apple is pulled from the tree. The PIVOT then further presses the handle into the hand to establish a sense of momentum and weight. When the user flicks their wrist and releases the handle, the apple is also automatically dropped in the simulation. The device was also tested when throwing and catching virtual objects.
The team ensured that the visual input was aligned to PIVOT in order to accurately render when the hand and the object make contact. It can achieve up to 0.55 milliseconds/degree, meaning it can transition from grasping to retracted at 190 degrees in 340 milliseconds.
Microsoft hopes to see this kind of technology being integrated more in virtual workplaces, as well as in manufacturing, where industrial designers or factory workers could feel virtual designs or products before they go into development.
The study on PIVOT can be accessed here. To see the rest of Microsoft’s haptic controls, visit https://www.microsoft.com/en-us/research/project/haptic-controllers/.
For more news and stories, check out this new VR headset HP is working on with Valve and Microsoft here.