Fall detection method and system

摘要

Abnormality detection means 21 performs an abnormality determination when a power supply line 2 has the voltage lower than a reference power supply voltage VDD. If any abnormality is detected, the detection result is forwarded to sensor output compensation means 22, indicating a voltage decrease from the reference power supply voltage VDD. Based on the voltage decrease, the sensor output compensation means 22 accordingly compensates a voltage signal Vout coming from an acceleration sensor 1. Fall determination means 23 plots, on a time axis, the voltage output Vout of the acceleration sensor 1 after compensation made by the sensor output compensation means 22, and based on any change observed for the voltage output Vout on the time axis, makes a fall determination. In such a structure, a method and system for correct fall detection can be provided, without causing cost increase, through acceleration detection made properly despite any decrease observed for the power supply voltage of an acceleration sensor.