Solve the car reversing radar - the working principle of the ultrasonic sensor. The reversing radar is called "Reversing Anti-collision Radar", also called "Parking Aid Device". It is a safety auxiliary device for parking or reversing cars. It is composed of ultrasonic sensors (commonly known as probes), controllers and monitors (or buzzers). Part of the composition.
It can inform the driver of obstacles around with the sound or more intuitive display, relieve the trouble caused by the driver's parking, reversing and starting the vehicle, and help the driver to remove the blind spots and blurred vision. Defects improve driving safety.
Ultrasonic (referring to mechanical waves above 20 kHz) is a special kind of sound wave with basic physical properties such as sound wave refraction, reflection and interference. The ultrasonic distance measuring sensor emits ultrasonic waves through the ultrasonic transmitting device, and measures the distance length by receiving the time difference of the transmitted ultrasonic waves through the receiver.
The ultrasonic transmitter emits an ultrasonic signal to a certain direction in the outside, and starts timing at the same time as the ultrasonic wave is emitted. The ultrasonic wave propagates through the air, and an obstacle encountered in the process of propagation will immediately return and propagate back, and the ultrasonic receiver receives the reflection. The time of the wave stops immediately. The propagation speed of the ultrasonic wave in the air is 340m/s, and the timer can measure the time from the launch point to the obstacle by recording the time t.
The length of the distance between the obstacles (s), ie: s = 340t/2.