| 摘要 |
<p>The invention relates to controlling deviations of the low-frequency circuit LFO (24) in a wheel unit (10) of a pressure monitoring system for vehicle tires, without increasing cost and at the same time enabling energy savings. In such a monitoring system, each wheel unit (10) comprises at least temperature sensors (14) and pressure sensors (16) connected to a signal control circuit (12), the sensors (14, 16) being activated according to an LFO circuit time base (24) integrated into the control circuit (12). An RF transmission circuit (20) for each wheel unit (10) transmits data stored in a memory (18) as well as an identifier of the unit (10) to a central unit of the system via an RF antenna (21). The transmission circuit (20) is synchronized by means of a high-precision clock (26). According to the invention, in each wheel unit (10), a variation ?Ti between a measured temperature Ti and a previously measured reference temperature is compared to a variation threshold ?T, and a deviation between the periods of the LFO circuit time base (24) and the transmission clock (26) is determined. The deviation is taken into account in order to adjust the time base (24) to the clock period (26), if the temperature variation ?Ti is greater than said threshold ?T.</p> |
