The working principle of automobile tire pressure sensor
At present, in order to ensure the safety of car driving, many car tires are equipped withpressure sensorsto detect the change of pressure, according to the relevant data statistics, tire pressure to a reasonable value, not only can improve the safety of driving, but also can save fuel consumption.So how does a car tire pressure sensor work?
Tire pressure monitoring system has two main solutions, direct system and indirect system.
Direct tire pressure monitoring system is to use the pressure sensor installed in each tire to directly measure the pressure of the tire, and the tire pressure display and monitoring, when the tire pressure is too low or leakage, the system will automatically alarm.
Direct tire pressure monitoring system is divided into active and passive two kinds.
The active system uses mems technology to make capacitive or piezoresistive pressure sensors on silicon base. The pressure sensors are installed on each wheel rim, and the signals are transmitted through radio frequency. The wireless receiving device installed in the cab receives the pressure sensitive signals, and after certain signal processing, the current tire pressure is displayed.
Indirect tire pressure monitoring system is to compare the speed difference between tires through the wheel speed sensor of abs system, so as to achieve the purpose of monitoring tire pressure. The main disadvantages of this type of system are:
1, can not show the accurate instantaneous pressure value of each tire;
2, the same axle or the same side of the wheel or all tire pressure drops at the same time can not alarm;
3, can not take into account the speed, detection accuracy and other factors.