A method is disclosed for analyzing the rolling of a rotating body that will make it possible to simultaneously achieve reduction in computational cost and attainment of adequate analytic precision. The method includes: a step (S100, S101) in which a structural model is acquired; a step (S103) in, which a region Ar1 on a rotating body T at which finely divided computational mesh cells are established is made to come in contact with the ground, and rolling analysis processing is performed in which rolling is made to occur in an amount that is an angle corresponding to N minimum units (where N is a natural number not less than 1); and a step (S105) in which mapping processing is performed in which physical quantities at computational mesh cells as they exist following the rolling analysis processing are copied to corresponding computational mesh cells at a rolling start time.

A control device of an electrified vehicle controls a drive motor that drives a tire-wheel assembly of a vehicle based on a torque target value set based on a state of the vehicle. A control device includes a torque command value calculation unit that calculates a torque command value based on a torque target value using a function representing inverse characteristics of transmission characteristics that represent a relationship between torque of a drive motor and acceleration of a vehicle body and that change according to a speed of a vehicle, which is caused by elasticity of a carcass portion of a tire of a tire-wheel assembly and viscosity in a tread of the tire, and a motor controller that controls the drive motor to output torque corresponding to the torque command value.

There is provided a computerized system comprising a processing unit and associated memory configured to obtain a three-dimensional dataset informative of at least part of a tread of a tire, and determine, using the three-dimensional dataset, data informative of tread depth of the tire.

A tire comprises a tread portion provided with grooves. When the tire mounted on a standard wheel rim and inflated to a standard tire pressure is placed on a flat surface at a camber angle of zero and loaded with a standard tire load, the tire has a ground contacting patch. The depths of the respective circumferential grooves, and ground contact lengths of the ground contacting patch measured at axial positions of the respective circumferential grooves, are in a relationship in which the groove depth increases or decreases as the ground contact length increases or decreases.

A tire comprises a tread portion provided with grooves. When the tire mounted on a standard wheel rim and inflated to a standard tire pressure is placed on a flat surface at a camber angle of zero and loaded with a standard tire load, the tire has a ground contacting patch. The depths of the respective grooves, and ground contact lengths of the ground contacting patch measured at axial positions of the respective grooves, are in a relationship in which the groove depth increases or decreases as the ground contact length increases or decreases.

A system and method are provided for Bayesian updating of distributions of factors that affect tire wear. Information is accumulated in data storage regarding probability distributions corresponding to each of a respective plurality of tire wear factors. Vehicle data comprising movement data and location data collected in association with a vehicle is transmitted from the vehicle to a centralized (e.g., cloud) computing device or network. At least one observation corresponding to one or more of the plurality of factors is generated based on the transmitted vehicle data. A Bayesian estimation is then generated of a tire wear status at a given time for at least one tire associated with the vehicle, based at least on the at least one generated observation and the stored information regarding probability distributions. The predictions accordingly carry a measure of uncertainty, and Bayesian inference can be used to update distributions based on the observations.

A system and method are provided for predicting the non-linear progression in vehicle tire wear. The system determines an original tread depth for a tire associated with a vehicle, and further determines an initial wear rate for the tire based at least partially on the original tread depth. One or more tire conditions are measured as time-series inputs to a predictive tire wear model, for example utilizing “brush-type” tire wear models for a contact interface between a base material of the tire and road surfaces, wherein the interface is represented as a plurality of independently deformable elements, wherein a current wear rate is normalized based at least partially on said inputs to the initial wear rate for the tire. The system can then predict a tire wear status of the tire for specified future parameters, such as for example a specified future distance traveled or a time traveled.

A system and method are provided for estimating progression in vehicle tire wear. A tread depth is stored at a first (e.g., initial or unworn) stage for a given tire, along with a first set of modal frequencies for the tire. At a later (e.g., worn) stage, for example in concert with a controlled excitation of tire structural modes, a second set of corresponding modal frequencies are sensed for the tire, and a tire wear status of the tire is determined at the second stage based on a calculated frequency shift between at least one corresponding modal frequency from each of the first and second sets. In one example, an initial mass of the tire is stored, and a change in mass is calculated based on the calculated frequency shift. Alternatively, a correlation of modal frequency shift may be performed with respect to tread depth for a given tire.

A processing device divides an initial tread pattern into multiple mutually adjacent partial patterns, each having a width smaller than that of the initial tread pattern, by at least one straight line along a circumferential direction of a tire. The processing device calculates variation amounts of characteristic values of the partial patterns with respect to the circumferential direction, based on a contact region, each of the characteristic values indicating a shape of a corresponding partial pattern. The processing device modifies the shapes of the partial patterns so as to reduce the variation amounts of the characteristic values of the partial patterns. The processing device relatively moves the partial patterns along the circumferential direction so as to reduce a total variation amount of characteristic values of at least two mutually adjacent partial patterns. The processing device combines the partial patterns with each other to generate a tread pattern of the tire.

A method for designing a pneumatic tire to have improved vibration characteristics. Dynamic testing of the tire detects a) respective frequencies of a plurality of radial vibration modes of the tire, and b) respective frequencies of a plurality of torsional vibration modes of the tire. The testing may determine that a first interval between the frequency of an even-numbered radial vibration mode and the frequency of an even-numbered torsional vibration mode is less than a first threshold, and/or may determine that a second interval between the frequency of an odd-numbered radial vibration mode and the frequency of an odd-numbered torsional vibration mode is less than a second threshold. One or more design parameter of the tire is/are modified to increase at least one of first interval and the second interval to the respective first or second threshold.