Will gesture control become the future of computer interfacing?

4 min read

For many years, we interfaced with our computers using a keyboard and a mouse. But the arrival of touchscreen technology has changed all that. Today, many of us will use touch as the main way to interact with our devices.

But even touch technology has its limitations; the user has to make physical contact with the device in question. Looking to address this issue, a number of companies and researchers are developing new ways to make devices understand what we want them to do – and gestures are being seen as a natural way of interaction. And some tvs are already offering just this ability. Samsung's Smart TVs, for example, support simple gesture control. Gesture control systems can take advantage of a range of technologies, including vision, sound and electrical field (e-field). Microchip has recently launched GestIC, an approach which uses e-field technology to enable interaction. Fanie Duvenhage is director of Microchip's human machine interface division. He said: "We're interested in how people connect with technology and that interaction between people and machines is getting interesting." GestIC technology, which is integrated into the host device, uses thin sensing electrodes made from any conductive material. Amongst the options are pcb traces and indium tin oxide coatings. The company says this allows for visually appealing industrial designs with very low additional system costs. The technology is also said to provide 100% surface coverage, eliminating 'angle of view' blind spots found in other technologies. Microchip has also supplied capacitive touch technology for some years. Duvenhage said that, while capacitive touch is still widely used, it has limitations. "The state of the art for capacitive touch only has a range of a couple of inches," he pointed out. GestIC technology uses frequencies of around 100kHz, with a wavelength of 3km. Because the electrodes are much smaller, their magnetic component is practically zero and no wave propagation takes place. The result, says Microchip, is a quasistatic electrical near field that can be used for sensing conductive objects. Five electrodes are required by the system: right, left, up, down and centre. When a hand, for example, enters the electrical field, its distribution is distorted and the field lines intercepted by the hand are shunted to ground through the human body. The proximity of the body shifts the receiver electrode signal levels to a lower potential and this can be detected. Digital signal processing determines the exact location of the gesture and its direction. Duvenhage said: "GestIC has a detection range of 15cm and, because it has low power consumption, can be always on." The first chip to enable the technology is the MGC3130. Consuming as little as 150µW in its active sensing state, the MGC3130 is suited for use in battery powered products, even with its always on nature. GestIC technology uses the Colibri suite, an on chip library of intuitive and natural human gestures. The Colibri suite combines a stochastic Hidden Markov model and x/y/z hand position vectors to provide designers with a reliable set of recognised 3d hand and finger gestures. Examples include position tracking, flicks, circles and symbol gestures. These can be used to perform functions such as on/off, open application, point, click, zoom and so on. The MGC3130 supports a resolution of 150point/in and samples at 200Hz sampling rate to detect the fastest motions. It features automated self calibration for high accuracy and has integrated flash to support product upgrades. Interference from other rf sources is avoided by a frequency hopping approach which shifts the detection frequency within the range from 70 to 130kHz. Microchip claims it is working with input device and other product manufacturers to implement efficient user input controls. Example applications include taking advantage of the interface capabilities in Windows 8, using hovering motions and free space gesture controls, instead of touchscreen interaction. Duvenhage believes GestIC technology will be suited to a range of markets. "Alongside consumer input devices," he said, "we also see potential in automotive and medical applications." Microchip is supporting developers with the Sabrewing single zone evaluation kit. Working with the MGC3130, the kit provides a choice of 5 or 7in electrode sizes and comes with the Aurea graphical user interface. This allow designers to match their system commands to Microchip's Colibri Suite. Sounds good According to Microsoft Research, gestures are becoming an increasingly popular way to interact with computers. However, it says deploying robust gesture recognition sensors in existing mobile platforms can be expensive. In a paper which describes its work, the team note that vision based gesture recognition systems can be affected by variables such as lighting conditions, while requiring reasonable amounts of processing power. The team also points to Microsoft's Kinect technology, but suggests miniaturising this is not likely in the near future. Looking to solve this problem, a team of researchers has developed a system called SoundWave, which takes advantage of the speakers and microphone found in most commodity devices. Sidhant Gupta, a ubiquitous computing researcher, is part of the team, whose approach is based on the Doppler effect. "SoundWave is a real time technique," said Gupta, "which uses speakers and a microphone to detect a range of gestures without the use of any special sensors." SoundWave generates frequencies in the range between 18 and 22kHz, which are frequency shifted when they reflect off moving objects, including the hand. "We use a microphone on the same device to pick up the frequency shifted signal and recognise the gesture," he continued. The system is also capable of detecting differences between gestures. For example, when the hand moves faster, the frequency shift is greater. And SoundWave can also understand when the user walks away from their laptop, for example, and can be set up to lock the device. Because SoundWave uses frequencies above the range of human hearing, it can work alongside audible music. "The user can have music playing on their laptop while using SoundWave," Gupta noted. In flight application Researchers from Thales are working on a gesture control system for in flight entertainment systems. According to the company, passengers will be able to interact with a large screen, with the camera recognising their motions and the system responding much as if they were using a touch screen. The idea is based on technology used in the Xbox games console, but Thales says the design goes beyond games and to address many aspects of in flight entertainment content: movies, music, gesture games and e-readers. But don't expect to find gesture control towards the rear of the plane. This system is intended for use by those who 'turn left' when they board. The reason? The distance between passenger and screen in the first and business class cabins. Thales is looking to make the first installation of the system as early as 2014.