A wheel assembly position identifying apparatus includes transmitters, each of which is provided in one of wheel assemblies and includes a transmission section and a control section, and a receiver, which includes a receiving section, a measuring section, and a wheel assembly position identifying section. The wheel assembly position identifying section is configured to detect, more than once, a rotational position of each wheel assembly at which the RSSI has an extreme value, for each position detecting signal received during one rotation of the wheel assembly, and identify the position of the wheel assembly in which the corresponding transmitter is provided based on variation of the rotational position of the wheel assembly at which the RSSI has the extreme value.

A wheel assembly position identifying apparatus includes transmitters, each of which is provided in one of wheel assemblies and includes a transmission section and a control section, and a receiver, which includes a receiving section, a measuring section, and a wheel assembly position identifying section. The wheel assembly position identifying section is configured to detect, more than once, a rotational position of each wheel assembly at which the RSSI has an extreme value, for each position detecting signal received during one rotation of the wheel assembly, and identify the position of the wheel assembly in which the corresponding transmitter is provided based on variation of the rotational position of the wheel assembly at which the RSSI has the extreme value.

A vehicle wheel information acquiring device includes a vehicle wheel sensor and a vehicle-body-side device. The vehicle wheel sensor is configured to revolve around an axle with a rotation of a vehicle wheel. The vehicle-body-side device includes a reception unit, a processing unit, a rotation position acquiring unit, an on-reception rotation position storage unit, and a determination unit. The determination unit is configured to determine whether a revolution position of the vehicle wheel sensor is included in an insufficient received intensity area during a stopping operation of a vehicle.

A method for detecting a foreign object under a vehicle fitted with a tire pressure monitoring system including at least two wheel units and a central unit including a communication device for communicating with each of the wheel units. The method includes a sounding step including a transmission phase which consists in transmitting at least one sounding signal from the first wheel unit to the second wheel unit across a transmission channel, and an analysis step which consists in comparing and in measuring differences in properties between the sounding signal received by the second wheel unit and a previously defined reference signal, and in determining whether the measured differences are characteristic of the presence of a foreign object present on the transmission channel taken by the sounding signal.