Abstract: A TPM system wheel unit measures rotational period over a number of wheel revolutions, calculates a value of a period of the revolutions and wirelessly transmits the calculated value of the period to a tire pressure monitoring system receiver in the vehicle mounting the wheel. Alternatively, each wheel unit transmits an RF burst of a predetermined length and a received RF burst envelope modulated with a periodic modulation pattern is used to calculate the period of one wheel rotation for each wheel. A central vehicle electronic control unit monitors wheel speed signals for each wheel of the vehicle and calculates a period for the wheel speed signal for each wheel of the vehicle, bounded by a rolling window which may be of variable length. The calculated values are compared and the wheel unit and the wheel location are correlated therefrom.

Abstract: A TPM system wheel unit measures rotational period over a number of wheel revolutions, calculates a value of a period of the revolutions and wirelessly transmits the calculated value of the period to a tire pressure monitoring system receiver in the vehicle mounting the wheel. Alternatively, each wheel unit transmits an RF burst of a predetermined length and a received RF burst envelope modulated with a periodic modulation pattern is used to calculate the period of one wheel rotation for each wheel. A central vehicle electronic control unit monitors wheel speed signals for each wheel of the vehicle and calculates a period for the wheel speed signal for each wheel of the vehicle, bounded by a rolling window which may be of variable length. The calculated values are compared and the wheel unit and the wheel location are correlated therefrom.

Abstract: A method and apparatus for communicating data in a remote tire pressure monitoring system (10) which includes a plurality of transmitters (12) associated with tires (T(1), T(2), T(3), and T(4)) of a vehicle (V) and a receiver (14) in radio communication with the plurality of transmitters. At each tire, data is collected (82), the data being representative of a tire characteristic, such as tire pressure. Data representative of the tire characteristic is transmitted (86). After a time delay (94, 96) next data are transmitted (98) until a predetermined number of data words have been transmitted. The time delay for each respective data word is defined according to a repeating pattern common to the plurality of tires so that data words are transmitted during a plurality of aperiodic time windows.