Touchless Control Next for Smartphones

Article By : Nitin Dahad

There is a race to market for the first devices with touchless/gesture control. Contenders at MWC Barcelona include LG, Google, and Apple, introducing products featuring human-machine interface (HMI) in 2019.

There’s a race on to market the first devices with touchless / gesture control. LG led the pack at MWC, and Google and Apple appear very close on its heels. Those two could possibly introduce products featuring this kind of human-machine interface (HMI) before 2019 is out.

The two latest trends in HMI technologies are voice activation and touchless or gesture control. Voice-controlled products received a lot of attention at Embedded World in Nuremberg; a prominent example was NXP Semiconductor’s new microcontroller featuring integrated Alexa Voice Service (AVS) capability, touchless control went almost unnoticed at MWC Barcelona, but it is equally being pursued aggressively by key players.

For example, LG launched its G8 ThinQ smartphone featuring Infineon Technologies’ Time-of-Flight (ToF) technology to enable smartphone authentication features as well as gesture control. LG G8 ThinQ features advanced palm vein authentication, using a combination of a ToF Z camera and infrared sensors. The Z camera enables control of phone functions without touching the phone, for example, by waving a hand or pinching the air, using the company’s Air Motion capability.

The feature is based on the REAL3 image sensor chip from Infineon and PMD Technologies. While other 3D sensing technologies utilize complex algorithms to calculate an object’s distance from the camera lens, the REAL3 image sensor chip claims to improve accuracy by capturing infrared light as it is reflected off the user or scanned object. As a result, ToF is faster and more effective in ambient light, reducing the workload on the application processor. This, in turn, lowers power consumption.

With 3D sensing heading towards ubiquity, Yole Developpement said the 3D imaging and sensing global market will reach US $18.5 billion in 2023. Research And Markets has estimated the broader market for touchless gesture recognition will reach $30.6 billion market by 2025.

Both Apple and Google appear to be aggressively pursuing gesture control, judging by their patent activity. We could see hover touch or touchless gesture control in products as early as this year.

Google recently received a second patent for its radar-based in-air gesturing. In addition, the Federal Communications Commission (FCC) recently granted Google a waiver of the FCC’s rules applicable to radars used for short range interactive motion sensing in the 57-64 GHz frequency band, allowing it to operate at higher power levels than currently allowed. Its Soli chip, developed with Infineon, incorporates the entire sensor and antenna array in a compact 8mm x 10mm package, to enable motion tracking of the human hand.

Google claims that unlike traditional radar sensors, its chip does not require large bandwidth and high spatial resolution. Instead, its fundamental sensing principles rely on motion resolution by extracting subtle changes in the received signal over time. By processing these temporal signal variations, it can distinguish complex finger movements and deforming hand shapes within its field.

The FCC issued a public notice asking for comments on the waiver request. The FCC said while some supported granting the waiver, others sought additional data from Google to allay concerns that Soli sensors might interfere with other devices that already operate in the same spectrum. They include authorized uses such as passive sensors in bands designated for earth satellites and radio astronomy, which might be interfered with by airborne devices employing Soli. There were also concerns about co-existence with unlicensed devices such as Wi-Fi (WiGig) products and other point-to-point short range devices, which all operate in the 60 GHz band.

In response, Google submitted simulations and measurement studies for the Soli sensor with various assumed power levels and duty cycles. The company conceded it could operate the sensors incorporating a lesser peak power than it sought in its waiver request. The current request indicates that an acceptable performance level can be achieved if Soli is permitted to operate at a peak transmitter conducted output power of +10 dBm (instead of –10 dBm as permitted in the FCC rules), and at a peak EIRP level of +13 dBm (instead of +10 dBm as permitted in FCC rules); as well as a peak power spectral density level of +13 dBm/MHz. Google states that it will limit the transmit duty cycle to 10 percent in any 33 millisecond interval.

The FCC waiver document appears to give Google a green light for moving forward with Soli. It indicated that the Soli sensors, when operating under the waiver conditions specified, pose minimal potential of causing harmful interference to other spectrum users and uses of the 57 64 GHz frequency band, including for the earth exploration satellite service and the radio astronomy service. “We further find that grant of the waiver will serve the public interest by providing for innovative device control features using touchless hand gesture technology,” according to the FCC.

Meanwhile, Apple has been working on hover-sensing multi-touch with a number of patents, the latest being for concurrent signal detection for touch and hover sensing. In 2013, it acquired Israeli 3D sensor company PrimeSense for a reported US $350 million.

Apple hover touch patent
Apple hover touch patent

After touch screens defined the first generation of smartphones, it’s quite possible that gesture control, or touchless control, may indeed be the next innovation to emerge in the smartphone human-machine interface. But it won’t just be limited to phones – Mazda, for example, said that it plans to eliminate touchscreens from cars because of the distraction they provide while driving; hover touch or gesture free could enable part of that human-machine interface in the car. Haptics is already being considered in automotive, as was recently reported with companies such as Ultrahaptics working on getting touchless control into gaming and cars.

Along with voice activation, touchless control is very likely to become more commonplace within the next 12 to 18 months.

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