Omni Device Can Simultaneously Actuate and Sense the Position of Handheld Tool
This 3D haptic feedback system can sense and actuate an untethered, passive tool containing only a small embedded permanent magnet.
Engineers from ETH Zurich’s Department of Computer Science have developed a novel 3D haptic feedback system for AR and VR applications using a simple tool and an electromagnetic base. Haptic feedback provides a sense of touch to AR and VR applications, creating an increased immersion level within those environments. Those haptic feedback units also allow for many different user interfaces, offering a denser information stream.
Most haptic feedback devices come in the form of handheld controllers, such as those found with the Xbox or Play Station, which rely on vibrotactile or linear resonant actuators. Those are novel in their approach but are limiting in vibrating the entire controller instead of localized areas. To that end, the team designed their Omni 3D haptic feedback system to give that missing localized sense of interaction with spatial haptic capability.
The Omni employs a simple tool with a passive magnet embedded within the end of the apparatus. At the same time, the base of the device houses an electromagnet and eight Hall effect sensors, which reconstructs the 3D position of the magnet in midair using data garnered from the sensors. According to the engineers, the 3DOF spherical electromagnet simultaneously exerts dynamic and precise radial and tangential forces in a volumetric space around the device, meaning no external tracking is needed to locate the position of the tool.
Three interwoven copper coils emit the haptic feedback force by governing the electrical current in each coil, which exerts a force on the permanent magnet within the Stylus-like tool. As the tool approaches the base, the Omni provides independently controlled radial and tangible forces, which are reflected onto 3D objects in an AR or VR environment. The team has utilized the Omni platform in several different applications, including a sculpting tool and CAD design apparatus, non-rigid object explorations, and gaming, using the tool as a joystick for steering cars in an AR racing game.