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Future of Sensor Fusion in Computing

Intel presented new capabilities for portable computing that are enabled by sensor Fusion at IDF 2012.  Sensor fusion has been associated mostly with smartphones.  Semico wrote an article discussing sensor fusion in a recent issue of the Semico IPI Report, August 2012.

Sensor fusion is not only the integration of more than one sensor but also the fusion of the data in order to use it for applications and enhance the user experience.  Sensors are defined as having a number of axes, also known as a degree of freedom (DoF).  Accelerometers can have up to 3 axes for the XYZ coordinate space.  A gyro measures the spin or rotation on each of the XYZ axes.  A magnetometer senses the magnetic angular rate and gravity (MARG) for each of the XYZ axes.  A magnetometer and accelerometer work together to achieve an eCompass function.  These sensors provide data from which direction and speed can be determined. The key application for sensor fusion is navigation and location based services (LBS).

As noted previously, more features are coming to the ultrabook which will require sensors.  Intel had technical sessions on sensors.  Windows 8 requires a minimum of 9 DoF.  Microsoft’s development program is Windows 8 Desktop.  This enables application developers to work with touch and sensors for tablet PCs and ultrabook PCs.  Microsoft offers a Windows Sensor Framework.  The Microsoft API allows developers to uniformly access sensors across platforms.

In addition to accelerometers, gyroscope, and magnetometers, Intel’s reference platforms for tablet PCs and ultrabooks include more sensors which can enable new applications beyond LBS or touch and motion control for gaming.  Other sensors that are being considered are altimeter (barometric pressure), ambient light, GPS, inclinometer, proximity, orientation and possibly more.

The application areas are security, gaming, entertainment and education.  Some functions being developed are geo-fencing, productivity tools via gestures and context awareness such as detecting motion for airplane mode.

Windows 8 specifies not only that there are at least 9 DoF but also that the sensor solution is certified.  Sensor fusion is required by Windows 8 for all tablet PCs and all convertible ultrabooks.  However, sensor fusion is only a recommendation for clamshell ultrabooks.  Of course, Intel is encouraging sensor fusion for clamshell ultrabooks.  In its reference design Intel shows a sensor hub which is a block connected directly to the CPU.  The sensor hub includes all of the sensors and a controller.  This is NOT a chip or subsystem from Intel.  The sensor hub can be from anyone of a number of vendors and the sensors could be from all one vendor or a variety.  In the August 2012 Semico IPI Report, Semico identified InvenSense, Freescale, STmicroelectronics and Kionix.  Other companies offer their algorithms for license such as Movea Technologies, Sensor Platforms, and PNI Sensors.  Intel calls out for the sensor fusion algorithm to be embedded in the sensor hub and not in the CPU.  While the CPU has more than enough processing power, according to Intel, constantly running the sensor algorithm would consume much more power than the sensor hub.

Semico Spin

The sensor hub provides data to the Windows Sensor Framework.  Microsoft and Intel are providing software development tools.  The possibilities for sensor applications for tablet PCs and ultrabooks is still at a nascent stage.  It will be exciting to see what application developers will deliver as more systems with sensor fusion hit the market.  These new capabilities and features will spur renewed interest by users and further drive upgrade cycles.

-Tony Massimini