실내 온도 및 객체 감지를 위한 듀얼 모드 초음파 센서

In this paper, we propose a dual-mode ultrasonic temperature sensor that, in addition to conventional object detection, can measure indoor temperature by exploiting the fact that the propagation speed of sound varies with temperature. To verify the accuracy and response characteristics of the ultrasonic sensor’s temperature-measurement capability, indoor temperature was varied while the sensor’s readings were recorded. The results were compared with three different commercial temperature sensors. In the accuracy test, the maximum error was ≤ 0.22 °C with respect to the reference temperature (measured by an infrared thermometer). In the dynamic-response test, the proposed sensor exhibited the fastest response among all sensors tested. For dual-mode operation, when an object taller than 30cm enters the sensing region, the sensor displays the measured height; when no object is present, it displays the ambient temperature. Experimental results confirm that the proposed dual-mode ultrasonic sensor can effectively deliver two functions with a single device.