False alarms triggered by temperature change detection of thermal imaging cameras

Applies to: TNM-C4945TD

Issue Summary

To monitor fires at electric vehicle charging stations, a thermal imaging camera is used to detect a rapid temperature change and to trigger an alarm. The camera is primarily intended to monitor rapid temperature changes around the charger and the vehicle's charging terminal.

However, the alarms sometimes go off frequently even when the temperature on the screen did not reach the set value. This happens because the sun reflects off objects (hood of the car, A-pillar, windshield, etc.) during the day, causing a momentary temperature rise. By setting the ROI area to the entire screen, alarms were triggered even for temperature rises in areas unrelated to the monitoring area.

Resolution

In environments where outdoor light reflection occurs, segment the ROI area to minimize false alarm generation. 

For example: Change the settings to divide the ROI area into zones 1, 2, and 3 to monitor only the areas actually requiring surveillance.