An estimation apparatus includes a rotation speed acquisition unit, a driving force acquisition unit, a slip ratio calculation unit, a slope calculation unit, and an estimation unit. The rotation speed acquisition unit sequentially acquires rotation speeds of the tires. The driving force acquisition unit sequentially acquires a driving force of the vehicle. The slip ratio calculation unit calculates a slip ratio based on the sequentially-acquired rotation speeds of the tires. The slope calculation unit calculates the slope of the slip ratio with respect to the driving force based on a large number of data sets of the slip ratio and the driving force, as a regression coefficient representing a linear relationship between the slip ratio and the driving force. The estimation unit estimates the wear state of the tires based on the slope.

A system compensates a drive over reader tire pressure measurement. The system includes a drive over reader, which includes a sensor array. A pressure indication is determined for each tire in a group of tires by the drive over reader. A recommended cold pressure for the tires is provided. An adjusted recommended pressure for the tires is determined from the pressure indication and the recommended cold pressure, and accounts for temperature effects on the tires. An adjusted low pressure threshold is set at a predetermined level below the adjusted recommended pressure. A notice is generated by the drive over reader for each tire that includes an adjusted recommended pressure below the adjusted low pressure threshold.

A system compensates a drive over reader tire pressure measurement. The system includes a drive over reader, which includes a sensor array. A pressure indication is determined for each tire in a group of tires by the drive over reader. A recommended cold pressure for the tires is provided. An adjusted recommended pressure for the tires is determined from the pressure indication and the recommended cold pressure, and accounts for temperature effects on the tires. An adjusted low pressure threshold is set at a predetermined level below the adjusted recommended pressure. A notice is generated by the drive over reader for each tire that includes an adjusted recommended pressure below the adjusted low pressure threshold.

A tire pressure monitoring device of an electric vehicle includes a wheel speed sensor sensing a speed of each wheel of the electric vehicle, and a controller selectively calculating an intercept value of ΔFR and a cumulative average value of the ΔFR based on a difference between a torque of a front wheel motor and a torque of a rear wheel motor, calculating an intercept value of ΔLR and an intercept value of ΔDiag based on the speed of each wheel, and monitoring a tire pressure of each wheel based on the calculated intercept value of the ΔFR or the cumulative average value of the ΔFR, the calculated intercept value of the ΔLR, and the calculated intercept value of the ΔDiag.

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 detection system for extracting information from a sensor module in a rolling wheel comprises: a sensor module which comprises a sensor adapted for sensing a physical property of the tire when mounted in a tire of the wheel or on an inner surface of a tire of the wheel; an acquisition module adapted for sampling a signal from the sensor module, thus obtaining a sequence of data samples; a correlation module adapted for cross-correlating a signed reference sequence with the sequence of data samples thus obtaining a correlation sequence; an extraction module adapted for identifying at least one perturbation in the correlation sequence, wherein the perturbation is induced when a part of the tire where the sensor is mounted hits the ground thereby forming the tire patch.

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.

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.

An electrostatic capacitance detection device is provided, which is provided with a first electrode, an insulating layer on the first electrode, and a second electrode on the insulating layer, the electrostatic capacitance detection device being configured to calculate a shear force applied from above an upper portion of the second electrode.

A method performed by an electronic device to monitor one or more wheels of a vehicle. 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, receiving second accelerometer measurements of a second accelerometer mounted on a vehicle's second wheel when the vehicle is moving during the interval of time, determining, based on the second accelerometer measurements, a second path followed by the second accelerometer when the vehicle is moving during the interval of time, and determining based on a comparison of the first path with the second path that at least one of the vehicle's first wheel and the vehicle's second wheel is misaligned.