Mobile Human Airbag System for Fall Protection Using MEMS Sensors and Embedded SVM Classifier

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper introduces a mobile human airbag system designed for fall protection for the elderly. A Micro Inertial Measurement Unit (<formula formulatype="inline"> <tex Notation="TeX">$\mu$</tex></formula>IMU) of 56 mm<formula formulatype="inline"> <tex Notation="TeX">$\,\times\,$</tex></formula>23 mm<formula formulatype="inline"> <tex Notation="TeX">$\,\times\,$</tex></formula>15 mm in size is built. This unit consists of three dimensional MEMS accelerometers, gyroscopes, a Bluetooth module and a Micro Controller Unit (MCU). It records human motion information, and, through the analysis of falls using a high-speed camera, a lateral fall can be determined by gyro threshold. A human motion database that includes falls and other normal motions (walking, running, etc.) is set up. Using a support vector machine (SVM) training process, we can classify falls and other normal motions successfully with a SVM filter. Based on the SVM filter, an embedded digital signal processing (DSP) system is developed for real-time fall detection. In addition, a smart mechanical airbag deployment system is finalized. The response time for the mechanical trigger is 0.133 s, which allows enough time for compressed air to be released before a person falls to the ground. The integrated system is tested and the feasibility of the airbag system for real-time fall protection is demonstrated. </para>