Provided is a tire air pressure transmission device configured to determine the rotational position of the tire air pressure transmission device based on a gravitational acceleration component of a centrifugal acceleration at the time of transmission of the tire air pressure information and to transmit in a wireless signal and at a prescribed cycle, tire air pressure information and tire air pressure transmission device rotational position information.

A method for pairing a measurement module with a wheel of a vehicle including, for each angular orientation signal associated with a specific wheel received by a computer, the steps of transmitting, by the computer, a measurement signal or a request to transmit a measurement signal to each module, measuring, by the computer or each module, a value of at least one parameter differentiating the signal, performing repetitions of the transmissions of measurement signals for each angular orientation signal received by the computer and storing values of the parameter, pairing a specific wheel with a measurement module when the values are substantially constant with a variation of less than 10% for the values, each wheel being associated with a module at the end of the method.

An air pressure abnormality determination system determines whether an air pressure abnormality in which an air pressure of at least one of multiple front tires and multiple rear tires drops. The front tires are front wheels of a vehicle. The rear tires are rear wheels of the vehicle and of which outer diameter is different from an outer diameter of the front tires. A determination is made on whether the air pressure abnormality occurs using a corrected wheel speed obtained by correcting one of a front wheel speed that is a wheel speed of the front wheels and a rear wheel speed that is a wheel speed of the rear wheels based on the outer diameter of the front tires and the outer diameter of the rear tires and an uncorrected wheel speed that is the other of the front wheel speed and the rear wheel speed that is uncorrected.

The present invention disclosed herein is a tire pressure monitoring system (TPMS) with a time encoded wireless tire condition sensing device and synchronization in which each transmitter ID is assigned its own timing parameter through the controlling device wherein each timing parameter has a different time delay to prevent any launch time transmission overlap and the main controller can function to sync the transmitters to prevent or correct any clock rate or clock frequency errors generated by the transmitters.

A tire monitoring apparatus comprising a monitor installed on a tire and a pulse width measuring apparatus for measuring the width of pulses produced by the monitor. The pulse width measuring apparatus comprises a frequency analyzer for producing a frequency representation of the pulse, a signal processor for determining a minimum value of the frequency representation, and a pulse width estimator that inverts the minimum value to produce a measurement for the pulse width. The tire monitoring apparatus uses the pulse width measurement as an indication of characteristics of the tire.

An assembly determines operating parameters of a tire. The assembly includes a tripod sensor mounted within an inner cavity of the tire underneath a crown portion and an innerliner on which the tripod sensor is mounted. The tripod sensor includes a tri-axial accelerometer for creating a circumferential signal for determining slip ratio, a lateral signal for determining a slip angle, and a radial signal for determining load on the tire.

Provided is a replacement necessity determination device for a snap-in valve having an inner end to which an air pressure detection device including an air pressure sensor and an acceleration sensor is coupled. A control device of the replacement necessity determination device is configured to predict an angle change amount of the snap-in valve and the air pressure detection device with respect to a wheel caused by a centrifugal force based on a rotational speed of the wheel and an acceleration detected by the acceleration sensor, calculate a degradation indication value of an elastic body of the snap-in valve based on a maximum value of the angle change amount during a period set in advance, and determine necessity of replacement of the snap-in valve based on an integrated value of the degradation indication value.

A tire theft alarming system includes a vehicular device mounted to a vehicle and a mobile device carried by a user of the vehicle. When a main power supply of the vehicle is in an OFF state, the vehicular device transmits a radio wave including a first alarm based on having a variation in air pressure or acceleration of a tire, which is mounted to the vehicle, detected by a sensor transmitter for detecting and transmitting the air pressure of the tire or the acceleration applied to the tire. The mobile device carries out a warning notification to a user based on having reception of a radio wave including a first alarm transmitted by the vehicular device.

A method for calibrating a radial acceleration sensor of a wheel of a vehicle including the following steps: acquisition, by the sensor, of signals S.sub.i, each signal S.sub.i being acquired during a predetermined time window W.sub.i when the vehicle is in motion, the windows W.sub.i being different from one another; detection, for each time window W.sub.i, of local extrema of the signal S.sub.i associated respectively with phase values and detection instants; determination, for each time window W.sub.i, of a frequency F.sub.i of the rotation of the wheel of the vehicle as a function of the phase values and of the detection instants for the local extrema detected; low-pass filtering of the signals S.sub.i, so as to obtain, for each time window W.sub.i, a filtered value Z.sub.i; calibration of a constant error E.sub.c of the radial acceleration sensor as a function of the filtered values Z.sub.i and of the frequencies F.sub.i.

A wheel assembly rotational position identifying apparatus includes an acceleration detector, a control section, and a battery. The control section identifies the rotational position of the wheel assembly based on an acceleration detected by the acceleration detector. The control section operates in a control mode that is a selected one of a normal mode and a power saving mode, in which a power consumption associated with identification of the rotational position of the wheel assembly is smaller than that in the normal mode. The control section switches the control mode to the normal mode when an initiation condition is met in accordance with an input from outside. The control section also switches the control mode to the power saving mode when a termination condition is met in the normal mode.