Tire pressure monitoring system principle
First of all, let's look at the so-called tire pressure monitoring system, it mainly includes direct tire pressure monitoring system "is" and "indirect tire pressure monitoring system" two kinds.
1) direct tire pressure monitoring devices
Direct tire pressure monitoring device is used to install in each tire pressure sensor to measure the pressure of the tire, directly using the wireless transmitter sends information from inside the tire pressure to the central receiver module in the system, and then to the tire pressure data for display. When the low tire pressure or gas leakage, the system will automatically alarm.
The benefits of tire pressure monitoring system is directly on each wheel is equipped with a pressure sensor and transmitter mounted, if any one on the driver's manual recommended tire down 25% cold tires tire pressure, will alert the driver. Its warning signal is accurate, and if a punctured tire, tire pressure fall, fast, direct tire pressure monitoring system can provide warnings immediately.
Another slow slow leak even tyres, direct tire pressure monitoring system can also through the driving computer to perceive, allows the rider to directly from the seat to examine the current four digital tire pressure, thus real-time learned four wheels real pressure conditions.
2) indirect tire pressure monitoring devices
Indirect tire pressure monitoring the working principle is: when a tire air pressure to reduce the weight of the vehicle can make the rolling radius of the wheel will be smaller, its speed is faster than other wheels, so you can through the comparison between tire speed difference, achieve the goal of monitor tire pressure. Indirect tire alarm system is, in fact, by calculating the tire rolling radius for pressure monitoring.
Indirect tire pressure monitoring device costs less than the direct type, it is actually on the automobile ABS braking system speed sensor is used to compare four tire rotation number, if one of the tire pressure is low, it will only tire rotation number and any other tyres, so adopt ABS system of the same sensor and the sensor signal, as long as the car computer make an adjustment in the software, can be in the driving computer to establish a new function, warning drivers a tire and tire pressure is lower than the other three information.
Such use indirect tire pressure monitoring device of the vehicle will appear two problems, one is the most used indirect tire pressure monitoring device models can't specific indicates the concrete which is a tire pressure is insufficient; Secondly if four tires tire pressure falling at the same time, so this device has failed, which is generally a particularly evident when the temperature drops in the winter. In addition, when the vehicle is through the detours, the lateral wheel rotation frequency will be greater than the medial rotation number, or the tyres in the sand or snow pavement skid, specific tire rotation number will be particularly high. So the calculation of the tire pressure monitoring methods have many limitations.