What’s TPMS

Nowadays, tire pressure monitoring system (TPMS) has gradually become a research and development concern in automotive electronics industry in China. It can not only warn car owners to pay attention to driving safety when tyres are on high pressure, low pressure and high temperature, but also help car owners save fuel and money and become one of the low carbon environmental protection group member. Now let's give a brief introduction on it.

Introduction of TPMS

TPMS is abbreviated as tire pressure monitoring system. This technology can record the speed of the tire or install an electronic sensor in the tire to automatically monitor the various conditions of the tire in real time, which can provide an effective safety guarantee for driving.

Classification of TPMS

The tire pressure monitoring system can be divided into two types:

Wheel－Speed Based TPMS(Abbreviation: WSBTPMS, or indirect TPMS) and Pressure－Sensor Based TPMS(Abbreviation: PSBTPMS, or direct TPMS)

WSBTPM needs to compare the speed difference between tires through the wheel speed sensor of ABS anti-lock braking system in order to monitor tire pressure. ABS determines whether the wheel is locked or not by the wheel speed sensor, thus deciding whether to start the anti-lock braking system or not. When the tire pressure decreases, the weight of the vehicle will make the diameter of the tire smaller, and the speed will change. The change of the Vehicle speed will trigger WSB alarm system, which reminds the car owner to pay attention to insufficient tire pressure. Therefore, WSBTPMS belongs to passive TPMS.

PSBTPMS is a system that uses pressure sensors installed on tires to measure the pressure and temperature of tires, and transmits pressure information from the inside of tires to the central receiver module by wireless transmitter. As a result, the tire pressure data will be displayed . When the tire shows high pressure, low pressure and high temperature, the system will alarm the car owner.  The owner can set tire pressure alarm value range and temperature alarm value by himself according to vehicle type, vehicle habits and geographical location. Therefore, PSBTPMS belongs to active TPMS.

There is still a big difference between WSBTPMS and PSBTTPMS. PSBTPMS can provide more advanced functions to measure the actual instantaneous pressure inside each tire at any time, so it is easy to determine the faulty tire. The cost of WSBTPM is relatively low. Vehicles equipped with four wheels of ABS (one wheel speed sensor per tire) only need to upgrade the software. However, WSBTPM does not have a high accuracy of PSBTPMS. It can not determine the fault tire at all. It will alarm only when the tire bursts , so PSBTPMS can only inform you when the danger occurs. It does not play a preventive effect. There will still be a great hidden danger. Its calibration is also extremely complex. In some cases, the system may not work properly, such as when the pressure of two tires on the same axle is low.