TIRE WEAR DEPTH ESTIMATING METHOD AND TIRE WEAR DEPTH ESTIMATING APPARATUS

A method and apparatus capable of estimating a tire wear amount even on snow-covered road surfaces accurately and reliably are provided. To that end, a differentiated acceleration waveform of a radial acceleration waveform of a tire is obtained, and an operation of calculating a leading-end differentiated peak value and a trailing-end differentiated peak value from the differentiated acceleration waveform is repeated a plurality of times. At the same time, a differentiated peak ratio, which is a ratio between the leading-end differentiated peak value and the trailing-end differentiated peak value, is calculated for each of the leading-end differentiated peak values and the trailing-end differentiated peak values obtained. Either one of the leading-end differentiated peak values and the trailing-end differentiated peak values, having a differentiated peak ratio within a lower limit range of 0.6 to 0.8 and an upper limit range of 1.0 to 1.2, or computed values of the leading-end differentiated peak values and the trailing-end differentiated peak values are extracted as the differentiated peak values for wear estimation. And the tire wear amount is estimated using the plurality of extracted differentiated peak values for wear estimation.