A car airbag detection system that uses a new type of capacitive readout circuit

This article presents a car airbag detection system that addresses long response times and high detection costs by using a new capacitive readout circuit. The system utilizes an STM32 as the control core and measures small capacitive signals through a planar capacitive sensor. When a target object approaches, the electric field of the sensor changes, allowing the system to detect related capacitive variations to determine proximity. Experimental results show that for standard capacitances ranging from 1 to 20 pF, the signal-to-noise ratio is between 75 and 80 dB, with an average of 75.71 dB. Furthermore, by controlling the object's approach to the sensor, the system can accurately detect capacitance changes, enabling the airbag to sense the front of the vehicle.