A method for obtaining the distance travelled by a tire comprises fixing a sensor, to the right of the crown with a radial position Rc, capable of generating a signal proportional to the acceleration experienced; rolling the tire at a rotation speed W, subject to a load Z; acquiring, after a time T, a first signal Sig.sup.i comprising the acceleration amplitude in the direction normal to the crown, wherein the values below a threshold N represent less than 40 percent of the length of the first signal; identifying a reference value V.sub.i.sup.reference, being the square root of the average value of the first signal Sig.sup.i; and determining the distance travelled D during the time T from the following formula: D=A*T*V.sub.i.sup.reference, where A is proportional to the square root of the rolling radius of the tire.

Sensor and method for determining operating states associated with one or more tires. The operating state of the tire can be determined based on one or more measures environmental conditions of the tire(s). For example, a controller can be configured to determine a change in one or more environmental conditions, including determining, for example, a rate-of-change value, a variance value, a standard deviation, or the like. The rate-of-change, variance, and/or standard deviation values can be compared to one or more threshold values to determine the operating state(s) associated with the tire(s). The environmental condition can include, for example, acceleration of the tire, pressure of the tire, and/or temperature of the tire. The operating state can be, for example, a filling state indicative of the tire being inflating, and/or a drive state indicative of the tire rotating about its axle.

A tire radius monitoring system for dynamically determining a tire effective radius for each of the wheels on a vehicle is described. The system includes a GPS sensor, a plurality of wheel speed sensors, and a controller. The controller determines, via the GPS sensor, a velocity vector related to longitudinal velocity of the vehicle. The controller determines wheel speeds for the plurality of vehicle wheels, and detects a no-wheel-slip state for the vehicle wheels and the velocity vector from the GPS sensor. The controller determines tire effective radii for the plurality of vehicle wheels based upon the velocity vector for the vehicle and the wheel speeds for the plurality of vehicle wheels during the no-wheel-slip state, and controls vehicle operation based upon the tire effective radii.

A measurement device for measuring the pressure of a wheel (3) of a vehicle, the measurement device comprising a stationary portion (5) and a movable portion (14) for being driven in rotation by the wheel, the stationary portion including a first printed circuit (7) having at least one first track formed thereon defining a first winding, the movable portion including a second printed circuit (16) having at least one second track formed thereon defining a second winding, the second printed circuit being arranged to be connected to a pressure sensor (15), the first winding and the second winding being coupled together to form a wireless communication channel, the measurement device being arranged in such a manner that the pressure sensor is electrically powered by the stationary portion via the wireless communication channel, and in such a manner that uplink data comprising pressure measurement data is transmitted to the stationary portion (5) by the movable portion (14) via the wireless communication channel.

A computer-implemented method can comprise determining, by a device comprising a processor, wear state information representative of a wear state of a tire of a vehicle based on an output from a sensor of the vehicle, and in response to the wear state of the tire being determined to exceed a tire wear threshold, generating, by the device, an alert signal associated with the wear state of the tire.

In a road surface condition determining device, when determining a road surface condition, a vibration detection unit, a waveform processing unit and a data transmission unit for implementing a sensing function and a data transmission function are not set continuously to an active state for all tire side device, but at least only one tire side device is set to an active state. Remaining one or more is set to a sleep state. A reduction in power consumption of the tire side devices set to the sleep state can thus be achieved. Further, with regard to the at least one tire side device, since the sensing function and the data transmission function remain in the active state, the road surface condition can be reliably determined based on the road surface data of the tire side device.

A sensor system for acquiring a perturbation, induced by a contact patch of a tire, in data generated by a sensor system mounted in the tire, comprises at least one sensor adapted for generating the data related to a physical property of the tire, and an acquisition system comprising memory. The sensor system is adapted for triggering the acquisition system to acquire the data and for storing it in a buffer in the memory, until a predefined delay after the perturbation is recognized. The perturbation is recognized by comparing the stored data with at least one characterizing feature of the perturbation.

Embodiments included herein are directed towards a method for estimating tire load. Embodiments may include determining a tire pressure associated with a tire and determining a tire angular velocity associated with the tire. Embodiments may further include obtaining one or more tire stiffness coefficients and determining a tire radial deformation based upon, at least in part, a length of a tire ground contact patch or a contact patch angle.

An auto-location system for auto-locating a wheel in a vehicle comprises: a sensor module which comprises a sensor adapted for sensing a physical property of the tire when mounted in a tire or on an inner surface of the tire of the wheel, an acquisition system adapted for determining when the part of the tire where the sensor is mounted hits the ground, and forms a contact patch with the ground, by analyzing data from the sensor, and a communication system adapted for transmitting a wireless message, in which a unique identifier is embedded, a transmit delay after the part of the tire where the sensor is mounted hits the ground.

An embodiment tire pressure sensor position identification apparatus includes a receiver configured to receive signals from tire pressure sensors and to receive information about wheel pulse counts from wheel speed sensors, the tire pressure sensors being mounted on an inner wheel and an outer wheel of a vehicle to have a specific phase difference therebetween, and a controller configured to identify positions where the tire pressure sensors are mounted based on the specific phase difference, the signals received from the tire pressure sensors, and the wheel pulse counts.