This prototypical system explores the combination of torque feedback with screen-based handheld devices.
Haptics, or kinesthetic communication, generally refers to tactile feedback that recreates the sense of touch by applying forces, vibrations, or motions to the user of a mobile device. And for those gamers out there, many of you can best associate to technology in the form of controllers and joysticks, most notably the “rumble” packs. However, since its inception over 30 years ago, not much has changed from days of the tactile telephone or Aura Systems’ Interactor Vest.
That was until now. A group of students from the University of Salzburg, Austria is looking to usher in a new era of haptics with the introduction of TorqueScreen. The prototypical system combines a handheld touchscreen device with an actuated flywheel capable of imposing angular momentum onto the tablet. According to its creators, the unique design of the project combines the movement and physics of virtual objects on the screen with the torque as haptic output imposed on the tablet.
“A widely distributed form of haptic feedback in handheld and mobile devices is vibrotactile feedback. However, the information capacity is very limited in vibrotactile feedback and not directly associated with conceptions of real space or real movement,” the team states in their paper. “Richer ungrounded haptic feedback can be provided by dynamically altering physical, inertial, and kinematic attributes (e.g. weight, velocity) of a device or interface.”
The prototype is comprised of a tablet, a brushless DC motor driving the flywheel and a servo motor rotating the gimbal. Or, in other words, TorqueScreen is a gyroscope actuator attached to a mobile device. Rotating the gimbal creates angular momentum around the torque axis, perpendicular to the rotational axis of the flywheel and the rotation of the gimbal. This allows the user to sense the tablet’s resistance to rotate about the servos axis. Both the motor controller and the servo are connected to an Atmel based Arduino, which handles the motor speed and position of the servos.
“Different speeds and movement patterns of the gimbal can be used to create torque feedback with varying characteristics, e.g., a constant rotation resulting in the sensation of the tablet being twisted towards a certain direction and quick rotations resulting in the sensation of some object tipping or impacting at different locations on the tablet’s surface.”
As our friends at Hackaday note, the team’s recent Tangible, Embedded, and Embodied Interaction Conference demonstration featured a brushless motor plucked from an old hard drive controlled by the Arduino and driven manually by a Wii nunchuck, which can be seen below.
“While our initial prototype has some limitations, it provides ways to study unexplored embodied interaction design beyond what is currently possible on handheld devices. In our future work, we aim to increase the prototype’s fidelity and the according interaction space by adding multiple degrees of freedom in a desirably smaller form factor.”
Interested in learning more? You can download the team’s entire paper here.
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