How to quickly judge whether the reversing radar is normal?

The reversing radar is a device to prompt the driver whether there are obstacles in front or behind when reversing, which is especially useful for novice driver friends. For example, we can judge the distance between the rear of the vehicle and the obstacle by the sound of the reversing radar. The louder the sound, the closer the distance between the rear of the vehicle and the obstacle. The failure rate of reversing radar damage is very small. When the radar is damaged, the easiest way to judge is to stand alone behind the car. If this radar doesn't work, it can be judged that the radar is damaged. Usually, there are four reversing radars at the back or front of the car, but this method can specifically determine which radar is damaged. Of course, there are other ways to judge besides this method. The analysis and classification of some reversing radars are very simple. That may be to connect the cable in the reverse gear and install the reversing radar on the bumper at the rear. For some cars, the requirements of the reversing radar system are very high, because the signals of the reversing radar need to be transmitted to the comfort control system of the vehicle. According to the overall framework of vehicle positioning and vehicle network, reversing radar can be divided into the following three categories: 1, with a separate control unit but no network protocol; 2. Independent control unit with transmission protocol connected to CAN bus. 3. There is no separate control unit, and the connection protocols are can bus and lin bus. 4. There is no separate control unit, and the connection protocol is only lin bus. Working Principle The reversing radar system is mainly composed of ultrasonic sensor (probe), controller and buzzer or monitor. As shown in the figure below, some reversing radar systems also have monitors, which are connected to the display in the central control interface. As a structure, when the gear of the transmission is hung on the reverse gear, the reversing radar system will start, and the ultrasonic probe installed on the bumper will send ultrasonic waves around. When encountering obstacles, ultrasonic waves will bounce and reflect, and the sensor will receive signals and send them to the controller. If a monitor is connected, we can see the strength of the signal through the monitor. Similar to cell phone signals. If this signal is full, it means that we are close to the obstacle. The method to judge the fault of the reversing radar is that the reversing radar system does not work when the reversing gear is put into gear or the radar switch is turned on, and there is no sound when the reversing radar approaches the obstacle. The circuit diagram of the reversing radar is shown in the following figure. As can be seen from the figure, when the reversing radar does not work, the main engine has no power supply, which may be caused by a circuit fault. Common fault causes include: battery switch is disconnected, controller is powered off, probe is pre-connected, buzzer is damaged, etc. When looking for faults, it should be analyzed in combination with the circuit diagram of relevant models. Some models adopt CAN bus control, so it is necessary to consider CAN bus frame and anti-collision ECU. The reversing radar does not work because the working conditions have not been reached. When the vehicle is parked uphill, due to the influence of the slope, the ultrasonic waves emitted by the radar can easily fail to detect obstacles, and small lattice objects may also fail to detect due to the volume problem. The fault of the reversing radar system is mainly the line fault between the probe and the controller, such as the damage of the reversing radar probe and the compression deformation of the line between the probe and the controller. If the reversing radar system uses lin line for transmission protocol, if one of the reversing radar systems is damaged, it will affect the failure of other radars. The buzzer on the instrument cluster sounds for 2 seconds. At this time, from the top of the instrument display screen, the detection area of the radar disappears, and there are words indicating the failure of the front or rear reversing radar. When the reversing radar system rings continuously, it will often lead to the damage of the reversing radar, cement and water droplets on the surface of the probe, internal faults of the probe, and virtual connection of the plug, thus causing abnormal working feedback voltage. The detection angle of the reversing radar is about 120 degrees. By generating ultrasonic waves to detect the distance from obstacles, the control unit thinks that if there is dirt on the surface, the radar will work normally. Summary and suggestion: In the process of reversing, the reversing radar is not omnipotent, so we should not rely too much on the reversing radar system. The reversing radar also has a blind spot for detection. If the height of the obstacle is not enough, or the obstacle is on the left and right sides of the car, there is nothing the reversing radar can do at this time. If the owner's friends are not confident in their own reversing technology, adding reversing images and 360 panoramic audio-visual system can maximize the safety when reversing. Of course, if you really can't grasp it, you can also get off and look around. This is the safest. If there is no reversing radar drill on the new car, it is best to postpone this configuration. It is recommended to install radar in 4s shop or professional repair shop. Because it is necessary to use a special reversing radar drill bit, there are certain requirements for the distribution of reversing radar spacing. If the bumper is damaged due to operational errors, the replacement price of a bumper will be higher than that of 700 yuan. This is irreversible.