Q: What is the working principle of an ultrasonic sensor?
A：An ultrasonic sensor is a sensor that uses ultrasonic waves for distance measurement or object detection. Its working principle involves emitting ultrasonic waves and receiving the echoes to calculate the distance between the target object and the ultrasonic sensor. The specific process is as follows:1. Emission: The sensor emits a high-frequency sound wave, usually ranging from 20kHz to 200kHz.2. Reception: When the sound wave encounters an object, it is reflected back to the sensor, and the sensor receives the reflected sound wave.3. Calculation: Based on the speed of sound and the time of reception, the time required for the sound wave to travel from the sensor and back is calculated.4. Distance calculation: Using the speed of sound and the time calculated, the distance between the sensor and the object is determined.