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EETE JULAUG 2014

Eurohaptics 2014 Augmented reality gets physical with haptics By Julien Happich if al of us are already familiar with the basic silent-mode of most mobile phones, a crude form of haptics (sensing the buzz of a vibrating mass in your pocket), there is much more to come on the display side. From the lab to startups, the race is on adding physically perceptible volumes and textures to whatever is displayed on screen, ranging from a simple keyboard with a “click” feel to the complex rendering of 3D shapes and textures, either in volume or on a seemingly flat surface. The EuroHaptics 2014 conference which took place in Versailles (France) from the 24th to the 26th of June was buzzing with actuators and haptic devices of all sorts. Well over a hundred papers, posters and dozens of demos were presented, covering experimental research setups about human touch perception on one end, and various tangible haptic interfaces on the other end of the spectrum, with plenty of force and feedback encoding schemes in between. Before any sensory information can be effectively put to good use in a haptic interface, one should understand how we humans perceive touch, and how our perception and our experience On the right, the haptic control pad developed by Continental, smooth but with distinct scroll & click feels for easy menu navigation. of the world affect our individual capacity to discriminate features and objects. A lot of fundamental research goes into understanding the limitations of touch-only haptic devices, versus multi-modal haptics where touch is combined with vision and/or sound to provide a better perceptual illusion. Often, the experiments show that a multisensory interface, as most of us would naturally experience with real world objects, provide a much better illusion and makes it easier for the enduser to manipulate virtual objects. Sometimes, they just highlight how a dual combination would be the most effective (sight and touch, or sound and touch). Then tricks can be developed by haptic device designers to tune into our perceptual illusions and create haptic feedback effects that are felt stronger or different than what the actual interface material really should provide (for example feeling a textured shape on a truly flat glass surface). One of the posters presented by Anke Brock from the CNRS & University of Toulouse was exploring the combinations of flat displays and haptics that would best suit visually impaired people for gestural interaction (touch displays often only offer visual cues). For the purpose of her investigation, Brock designed an interactive map prototype including a raised-line map overlay for gestural interaction with contoured buttons for accessing different types of information such as opening hours, distances. The drawings were made in the Scalable Vector Graphics (SVG) with a configuration file written in XML so as to be interpreted by the interface application. The physical overlay was painstakingly custom made and static. But ideally, this is an area where dynamically reconfigurable haptic displays could play a bigger role. Nowadays, you’ll find subtle haptic effects to replace the clicking feel of buttons and scrolling wheels in high-end consumer applications, such as in the cockpit of Mercedes Benz’s latest 2014 C-Class model BR205, where the overall HMI can be controlled through a central pad with no moving parts. The smooth curved touchpad developed by Continental combines a capacitive touchpad overlay and proximity light sensors for finger detection, and built-in coils that vibrate the assembly. The haptic feedback characteristics can be tuned in a wide range by varying the position and force level for the “press” state and the length of the haptic pulse profile. Targeting high-end white appliances and medical equipments, startup company Aito offers so-called Software Enhanced Piezo technology, combining piezoelectric sensing and a feedback loop processed through the dedicated AitoChip companion chip to drive 200mm thin piezo-actuators stacked underneath the user interface. Because it is a very low cost and highly reliable solution (no moving parts), Aito’s CEO Rene de Vries hopes his solution will become an industry standard, enabling the comforting “click” feel of mechanical switches even through the toughest steel, glass or ceramic casings (not excluding plastic or wood). The company has even set up a web portal, http://sep-touch.org/ to foster a community of software developers and technology partners around its Aito chip. “Now we are too small a company to approach the automotive market, but as we get more visibility, I am sure that automakers would see the benefit of our technology”, told us de Vries, claiming that his piezoelectric solution is much more cost effective and simpler to implement than coil-based solutions. Aito’s Software Enhanced Piezo technology relies on very thin embedded piezoelectric discs driven by a companion chip for touch-sensing and active feedback. 8 Electronic Engineering Times Europe July/August 2014 www.electronics-eetimes.com


EETE JULAUG 2014
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