Tire information obtaining device, method for obtaining tire information and tire information obtaining program

摘要

A vehicle wheel speed is calculated based on a vehicle wheel speed signal outputted from a vehicle wheel speed sensor and a change width w which is an amplitude of a time change component of the calculated vehicle wheel speed. When the calculated change width w is equal to or more than a reference value w₀ it is judged that a quick tire deformation is currently generated and a driver of the vehicle is informed of the quick deformation by actuating a warning device.