Vehicle-mounted emergency report device

摘要

A vehicle-mounted emergency report device having a function of transmitting an emergency report signal to a center device via a communication network when a vehicle has been determined to collide, includes a backup battery supplying an operating power when electric power supplied from a vehicle battery decreases, and a voltage detection unit detecting a voltage of the backup battery. Also, the vehicle-mounted emergency report device has a first determination unit determining whether the voltage detected is lower than a battery exhaustion warning threshold, a second determination unit determining whether a second order differential coefficient calculated by differentiating a battery voltage function twice by time is negative, and a warning unit refraining from warning when the voltage detected is lower than the threshold and the coefficient is not negative, and warning when the coefficient is negative. Thus, decrease of a discharge performance of the backup battery can be detected accurately.

主权项

1. A vehicle-mounted emergency report device mounted in a vehicle that has a function of transmitting an emergency report signal to a center device via a communication network and is configured to operate using electric power supplied from a vehicle battery as operating power, the vehicle-mounted emergency report device comprising:
a backup battery supplying the operating power to operate the vehicle-mounted emergency report device when the electric power supplied from the vehicle battery decreases; a voltage detection unit detecting a voltage of the backup battery; a first determination unit determining whether the voltage detected by the voltage detection unit is lower than a battery exhaustion warning threshold; a second determination unit determining whether a second order differential coefficient calculated by differentiating a battery voltage function of the backup battery twice by time is negative; and a warning unit:
refraining from warning of battery exhaustion when the voltage detected is lower than the battery exhaustion warning threshold and the second order differential coefficient is not negative; andwarning of the battery exhaustion when the voltage detected is lower than the battery exhaustion warning threshold and the second order differential coefficient is negative.