What is the method for parking sensors to detect distance?
2 Answers
Parking sensors detect distance by: judging the distance through sound. The alarm emitted by parking sensors is a beeping sound at a certain frequency, and the frequency increases as the obstacle gets closer. When the beeping frequency becomes faster and is accompanied by a continuous sound, it indicates that the vehicle is getting closer to the obstacle. Parking sensors mainly consist of ultrasonic sensors, a controller, and a buzzer. Their main functions are: 1. Accurately measuring the distance between the rear of the vehicle and the obstacle; 2. Emitting an urgent warning sound when reversing into a dangerous distance to alert the driver to brake; 3. Repeatedly emitting a voice warning sound to alert pedestrians.
The method for reversing radar to identify distance primarily utilizes ultrasonic technology. The radar system emits high-frequency sound wave pulses, which bounce back when they hit an obstacle. The sensor then calculates the time difference between emission and reception of the echo. Knowing the speed of sound in air, approximately 340 meters per second, the distance can be calculated: distance equals the time difference divided by 2 and then multiplied by the speed of sound. This is similar to how bats navigate—simple and efficient. In practical applications, the radar system is usually installed in the rear bumper of the car, with multiple sensors covering different angles to avoid blind spots. After prolonged use, the sensors may become covered with mud or snow, affecting accuracy, so they need to be cleaned promptly. Some modern car models also integrate cameras or alarm systems to make reversing safer and more reliable.
