What is the principle of BYD Song Pressure Monitoring?

Car tire pressure monitoring principle: 1. The principle of automotive tire pressure monitoring has three direct tire pressure monitoring: the direct tire pressure monitoring device is to directly measure the air pressure of the tire by mounted the pressure sensor mounted in each tire, using wireless emission The power information is sent from the inside of the tire to the central receiver module, and then the tire pressure data is displayed; when the air pressure is too low or leaking, the system will automatically alarm; 2, indirect tire pressure monitoring indirect tire pressure The working principle of the monitoring is: When the air pressure of a tire is lowered, the weight of the vehicle will make the rolling radius of the wheel will be small, resulting in fast speed than other wheels; through the difference between the tires, to achieve monitoring tire pressure the goal of. The indirect tire alarm system actually rely on calculating the tire rolling radius to monitor the air pressure; Function, at any time measurement of the actual instantaneous pressure inside each tire, it is easy to determine the fault tire. The indirect system cost is relatively low, and a car that has been equipped with 4 rounds of ABS (1 wheel speed sensor for each tire) simply upgrade software; however, the indirect tire pressure monitor does not have a direct system accuracy, it fundamentally The fault tire cannot be determined, and the system calibration is extremely complicated. In some cases, the system will not work properly, such as the two tire pneumatic pneumators of the same axle.