Abstract: Indirect tire pressure monitoring system (TPMS), which works by using the pulses from wheel sensors of anti-lock braking system (ABS), operates correctly only on straight or approximate straight roads. So it is unavailable in curving path. On the foundation of the standard pulse number (SPN) comparing method used under the straight road condition, the features of SPN of 4 wheels in cornering status is studied deeply. The kinetic model of a car in cornering is built. By using the relationship among the turning radii of four wheels shown in the model, the calculating equations are deduced. According to the calculating cornering radii, the travel distances of four wheels are regulated, and the SPN is amended with equivalent principle between curving paths and straight roads, so as to make cornering driving equivalent to straight driving, then the new method can monitor tire pressure in case of travel on curving path. The prototype of TPMS made in this principle is tested in a vehicle on road. The test result shows that its monitoring efficacy is good, which provides a method for monitoring tire pressure on curve lanes and expands the monitoring area of indirect TPMS. The theory and the method can be used in the development of indirect TRMS products.

Key words: Cornering radius, Indirect tire pressure monitoring system (TPMS), Monitoring method, Standard pulse number