PROJECT SOLI
-Blog By Mohammad Saquib (Final Year Student, ETC, ACET, Nagpur)
Wave hello to Soli touch-less interactions:
Soli is a new sensing technology that uses
miniature radar to detect touch-less gesture interactions. We envision a future
in which the human hand becomes a universal input device for interacting with
technology.
The
Soli chip incorporates the entire sensor and antenna array into an ultra
compact 8mm x 10mm package.
The concept of Virtual Tools is key
to Soli interactions: Virtual Tools are gestures that mimic familiar
interactions with physical tools. This metaphor makes it easier to communicate,
learn, and remember Soli interactions.
Virtual Tool Gestures
Imagine
an invisible button between your thumb and index fingers – you can press it by
tapping your fingers together.
Or a Virtual Dial that you turn by rubbing thumb
against index finger. Imagine grabbing and pulling a Virtual Slider in thin
air.
These are the kinds of interactions we are
developing and imagining. Even though these controls are virtual, the
interactions feel physical and responsive.
Feedback is generated by the haptic sensation of
fingers touching each other. Without the constraints of physical controls,
these virtual tools can take on the fluidity and precision of our natural human
hand motion.
How
does it work?
Soli
sensor technology works by emitting electromagnetic waves in a broad beam. Objects
within the beam scatter this energy, reflecting some portion back towards the
radar antenna. Properties of the reflected signal, such as energy, time delay,
and frequency shift capture rich information about the object’s characteristics
and dynamics, including size, shape, orientation, material, distance, and
velocity.
Soli
tracks and recognizes dynamic gestures expressed by fine motions of the fingers
and hand. In order to accomplish this with a single chip sensor, we developed a
novel radar sensing paradigm with tailored hardware, software, and algorithms.
Unlike traditional radar sensors, Soli does not require large bandwidth and
high spatial resolution; in fact, Soli’s spatial resolution is coarser than the
scale of most fine finger gestures. Instead, our fundamental sensing principles
rely on motion resolution by extracting subtle changes in the received signal
over time. By processing these temporal signal variations, Soli can distinguish
complex finger movements and deforming hand shapes within its field.
Soli
gesture recognition
The Soli
software architecture consists of a generalized gesture recognition pipeline
which is hardware agnostic and can work with different types of radar. The
pipeline implements several stages of signal abstraction: from the raw radar
data to signal transformations, core and abstract machine learning features,
detection and tracking, gesture probabilities, and finally UI tools to
interpret gesture controls.
The Soli
SDK enables developers to easily access and build upon our gesture recognition
pipeline. The Soli libraries extract real-time signals from radar hardware,
outputting signal transformations, high precision position and motion data, and
gesture labels and parameters at frame rates from 100 to 10,000 frames per
second.
The Soli
sensor is a fully integrated, low-power radar operating in the 60-GHz ISM band.
In our journey toward this form factor, we rapidly iterated through several
hardware prototypes, beginning with a large bench-top unit built from
off-the-shelf components -- including multiple cooling fans. Over the course of
10 months, we redesigned and rebuilt the entire radar system into a single
solid state component that can be easily integrated into small, mobile consumer
devices and produced at scale.
The
custom-built Soli chip greatly reduces radar system design complexity and power
consumption compared to our initial prototypes. We developed two modulation
architectures: a Frequency Modulated Continuous Wave (FMCW) radar and a
Direct-Sequence Spread Spectrum (DSSS) radar. Both chips integrate the entire
radar system into the package, including multiple beam forming antennas that
enable 3D tracking and imaging with no moving parts.
What
are the potential applications of Soli?
1. The
Soli chip can be embedded in wearable, phones, computers, cars and IOT devices
in our environment.
2. Soli
has no moving parts, it fits onto a chip and consumes little energy. It is not
affected by light conditions and it works through most materials. Just imagine
the possibilities...
