Mobile Human Airbag System for Fall Protection
Guangyi Shi, Cheung Shing Chan, Wen J. Li, Kwok-Sui Leung, Yuexian Zou, Yufeng Jin · 2009
This paper introduces a mobile human airbag system designed for fall protection for the elderly. A Micro Inertial Mea- surementUnit( IMU)of56mm 23mm 15mminsizeisbuilt. This unit consists of three dimensional MEMS accelerometers, gy- roscopes, 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 clas- sify 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. Index Terms—Digital signal processing (DSP), human motion sensing, microelectromechanical systems (MEMS), inertial mea- surement unit ( IMU), mobile airbags, support vector machine (SVM).