What Principle Does the Reversing Radar Apply?
3 Answers
When reversing, the reversing radar utilizes the principle of ultrasound. The sensor installed on the rear bumper emits ultrasonic waves that reflect off obstacles, and then calculates the actual distance between the vehicle and the obstacle. Below is relevant knowledge about reversing radars: 1. Introduction: The reversing radar, also known as the "reverse anti-collision radar" or "parking assist device," mainly consists of ultrasonic sensors, a controller, and a display. 2. Functions: Accurately measures the distance between the rear of the vehicle and the nearest obstacle; when reversing to the limit distance, it can emit rapid warning sounds to remind the driver to brake; it can repeatedly emit voice warnings to alert pedestrians.
The reversing radar operates on the principle of ultrasonic echo, much like bats navigating in the dark. Several sensors are installed on the rear of the car, emitting ultrasonic pulses that bounce back upon hitting obstacles. The receiver calculates the distance based on the time it takes for the sound waves to travel back and forth. Nowadays, many cars come equipped with this feature, typically with four to eight sensors. The faster the beeping sound, the closer the obstacle is. However, it has limitations—it may not detect low flower beds or thin poles, and icy conditions in winter can cause false alarms. It's recommended to use it in conjunction with a reversing camera for safer parking. Also, remember to clean the sensors during car washes, as mud buildup can reduce their sensitivity.
The technician who installed the reverse radar explained to me that its working principle is essentially sonar technology. The control unit in the car sends ultrasonic waves through the sensors, which bounce back when encountering obstacles like walls or pillars. The chip calculates the time difference to display the distance. The most practical feature is the three-tier alarm system: slow beeps at around one meter, faster beeps starting at half a meter, and continuous high-pitched alarms within thirty centimeters. However, it can only detect objects on the horizontal plane behind the car, making it easy to miss low obstacles like parking locks, and it may also give false alarms in rainy weather. That's why I always double-check with both the radar and the rearview mirror when reversing—it's the most reliable method.
