The invention relates to a system for determining the tire condition of a vehicle tire in a vehicle, said system comprising a number of sensors, which detect measurement values (m.sub.1, m.sub.2, m.sub.3) relevant to the tire condition, and a device for recording data and transmitting data, said device having a signal connection to the sensors on the input side. According to the invention, the signal output of the device has a preferably wireless signal connection to a readout unit, and the device generates actual tire parameters on the basis of the detected measurement values (m.sub.1, m.sub.2, m.sub.3) and directs said actual tire parameters to the readout unit.

An apparatus for monitoring the condition of a pneumatic tyre including a pressure sensor(s) to measure an internal pressure within the tyre. A speed sensor(s) measures a rotational speed of the tyre. A controller is configured to receive data from the pressure sensor and the speed sensor and output indications related to a condition of the tyre. The controller determines the output indications by tracking the internal pressure with respect to time during use of the tyre, identifying at least one change in internal tyre pressure in a time interval. The time interval is between a first reference time and a second reference time, the reference times corresponding to points at which the speed sensor indicates different rotational speeds of the tyre. The controller further monitors the pressure change as a function of rotational speed of the tyre to provide an indicator of tyre condition.

A method, for evaluating the variation in the dynamic load borne by a tire comprising a front axle and a rear axle, comprises steps during which: the pressure of the air contained inside the tire is measured, a difference in load borne by the tire is determined as a function of the transfer of the total load of the vehicle between axles and of the position of the tire on the vehicle and, using a tire model that is preestablished, a pressure differential is determined, a corrected pressure value is determined, on the basis of the corrected pressure values, a reference pressure is determined, and the difference between the measured pressure in the reference pressure is calculated, and the variation in dynamic load borne by the tire is determined on the basis of the model of the tire.

A pneumatic tire includes a first tread area portion, an electric power source, a transmission device, an accelerometer, and a control unit configured to operate in a power saving mode and a normal mode. A contact of the first tread area portion with a surface is detected by sensing acceleration of the first tread area portion by the accelerometer. The control unit is configured to switch from the normal mode to the power saving mode after a detection that the first tread area portion is on a contact patch of the tire. The control unit is configured to switch from the power saving mode to the normal mode when a first specified time depending on the rotation speed of the tire has elapsed since the detection that the first tread area portion is on the contact patch. A monitoring method and a system are used with the pneumatic tire.

A dead-reckoning guidance system determines a vehicle-speed of the host-vehicle based on wheel-signals from the one or more wheel-sensors; determines a distance-traveled by the host-vehicle during a time-interval since prior-coordinates of the host-vehicle were determined; determines a heading-traveled of the host-vehicle during the time-interval since the prior-coordinates of the host-vehicle were determined; determines present-coordinates of the host-vehicle based on the distance-traveled and the heading-traveled; determines when the vehicle-speed is greater than a speed-threshold; determines when the heading-traveled differs from a cardinal-direction by both greater than a noise-threshold and less than an angle-threshold; and in response to a determination that both the vehicle-speed is greater than the speed-threshold and that the heading-traveled differs from the cardinal-direction by both greater than the noise-threshold and less than the angle-threshold, determines a coordinate-correction to apply to the present-coordinates, said coordinate-correction determined in accordance with the distance-traveled and the cardinal-direction.

A transmitter is configured to be integrated with a tire valve attached to a wheel. The transmitter includes a data generating unit, a transmitting unit, and a controlling unit. The data generating unit is configured to generate transmission data. The transmitting unit is configured to transmit the transmission data to a receiver that includes a setting unit that sets a threshold related to control of a vehicle in accordance with a type of the wheel. The controlling unit causes the transmitting unit to transmit the transmission data. The transmission data includes wheel identification information. The wheel identification information is required by the setting unit when setting the threshold and allows the setting unit to recognize the type of the wheel to which the tire valve is attached.

A transmitter includes a data generating unit configured to generate transmission data, a transmitting unit configured to transmit the transmission data to a receiver that includes a setting unit that sets a threshold for controlling a vehicle in accordance with the type of the tire valve, and a controlling unit that causes the transmitting unit to transmit the transmission data. The transmission data is information with which the setting unit sets the threshold. The transmission data includes valve identification information for causing the setting unit to recognize the type of the tire valve to which the transmitter is attached.

Methods and apparatus for determining whether a vehicle tyre pressure check has been carried out, comprising: receiving from a pressure reader module a request for tyre pressure data indicative of a the pressure of a gas retained within a pneumatic tyre; storing, by a pressure check register, data indicating that the request for tyre pressure data was received; transmitting, by a transmitter to an apparatus, an indication confirming whether a tyre pressure check has been carried out based on whether the request for tyre pressure data was received; receiving, at the apparatus from a plurality of tyre pressure sensing modules, a plurality of indications of whether a tyre pressure reader has been used on each of the plurality of tyre pressure sensing modules to check a corresponding tyre pressure; and determining, by a pressure check confirmer, whether a vehicle tyre pressure check has been carried out based on the received plurality of indications.

Deformation of a surface, such as a pavement surface is measured using a rolling weight or wheel carrying one or more accelerometers positioned to measure the deformation occurring at a point on or near the perimeter of the wheel. The weight is rolled over the surface to be measured. The signals developed by the one or more accelerometers during a stationary cycloidal period of the point on the perimeter of the wheel are analysed to provide a measure of surface deformation based on the one or more signals.

A method of monitoring one or more wheels of a vehicle is described. The method includes receiving first accelerometer measurements of a first accelerometer mounted on the vehicle's first wheel when the vehicle is moving during an interval of time, determining based on the first accelerometer measurements a first path followed by the first accelerometer when the vehicle is moving during the interval of time, determining based on the first path that the vehicle's first wheel is out of balance with respect to an axle of the vehicle's first wheel, and responsive to determining that the vehicle's first wheel is out of balance, transmitting to a user device a first alert that the vehicle's first wheel is out of balance.