Ultrasonic range finder Ultrasonic range finder is measured according to the characteristics of ultrasonic waves reflected from obstacles. The ultrasonic transmitter emits ultrasonic waves in a certain direction, and starts timing at the same time. The ultrasonic wave propagates in the air. When it encounters an obstacle on the way, it returns immediately. The ultrasonic receiver immediately stops the timing when it receives the reflected wave. After the launch, the echo reflected by the obstacle is encountered, so as to measure the time difference T between the transmitted ultrasonic wave and the received echo, and then the distance L is obtained. Ultrasonic range finder, because the ultrasonic wave is greatly affected by the surrounding environment, so the general measurement distance is relatively short, and the measurement accuracy is relatively low. At present, the scope of use is not very broad, but the price is relatively low, generally about a few hundred yuan.
