Towards a mobile airbag system using MEMS sensors and embedded intelligence

This paper introduces the development of a mobile human airbag system that is designed for fall protection for the elderly. A Micro Inertial Measurement Unit (mulMU) that is 66 mm x 20 mm x 20 mm in size is built. This unit consists of three dimensional MEMS accelerometers, gyroscopes, and a Bluetooth module. It records human motion information, and, with a Support Vector Machine (SVM) training process, we can classify falls and other normal motions successfully with an SVM filter. Based on the SVM filter, an embedded DSP (Digital Signal Processing) system is developed for real-time fall detection. Also, a smart mechanical airbag deployment system is finalized. This system weighs 253.5 grams (including a 42.5 g compressed CO₂ cylinder) and is 190 mm long, 57 mm wide, and 30 mm thick. Its size will be reduced in future to allow it to fit onto a belt. The response time of the trigger is 0.133 seconds, which allows more time for compressed air release before a person falls down to the ground. The integrated system is tested, and the feasibility of the airbag system for real-time fall protection is demonstrated.