When it comes to the business of “stuff tracking,” there are few factors more important than power conservation. The list of startups promising the latest low-power solution seems to grow exponentially each year, and most recently includes Bosch Sensortec—a subsidiary of German electronics and engineering giant Bosch.
Bosch Sensortec is mainly known for delivering a variety of motion and environmental sensors, such as pressure detectors for wearables. The company’s newly announced sensor—the BHI160BP—is also aimed at wearables, but this device tackles location, not environment.
The new sensor is a position tracker that aims not to replace, but to improve, what GPS and GNSS can already do. Improving GPS is a big feat to achieve, but Bosch tackles it by adding motion sensors into the mix. At first glance, this might seem like overkill, but in fact the motion sensors can improve the battery life of a smart device by allowing the power-sapping GPS/GNSS module to be turned off for long periods of time, which lets the motion sensors take over to approximate the wearer’s position.
“The BHI160BP tracks a person’s position by intelligently applying an inertial sensor based algorithm for Pedestrian Dead Reckoning (PDR),” explains Bosch Sensortec in a press release. “To maintain accuracy, it calculates the user’s relative location based on data collected from the inertial sensors and then re-calibrates itself every few minutes to obtain the absolute position provided by the GNSS/GPS module. This means that the GNSS/GPS module can be kept in sleep mode for most of the time, which drastically reduces a device's power consumption and extends its operating time.”
According to Bosch, the powered-on-only-when-you-need-it system is effective enough to preserve up to 80 percent of power consumption compared to a tracker that uses only GNSS. Even in active operation mode, the device only draws 1.3mA. Although many consumers likely charge their smart watches every night, a lower power requirement allows for a smaller-sized battery, leaving more space in the device for extra processing power, or more gadgets. Using internal motion sensors also means that the device can track a user’s position when a GNSS would otherwise fail—such as indoors, or in locations such as on the subway.
“Pedestrian position tracking is a crucial application for mobile applications; unfortunately, GPS modules can rapidly drain a device’s battery capacity—especially when the battery is as small as in wearable devices,” explained Stefan Finkbeiner, CEO of Bosch Sensortec.
According to Bosch, the position tracking sensor is the industry’s first, as the motion sensors put its capabilities above and beyond a standard GPS or GNSS module.
Although the motion sensor is designed for location tracking, in principle, there’s no reason that it can’t be used to perform additional tasks such as gesture recognition and 3D orientation. Bosch states that the sensor itself can handle the required 3D calculations. Further customized virtual sensors include a calibrated accelerometer and a wake-up gesture. A magnetometer can also be installed in the sensor.
The BHI160BP, which measures 3 mm x 3 mm x 0.95 mm, is pin-to-pin compatible with the BHI160. It will be available via distribution beginning in December 2018.