| 摘要 |
In order to achieve a further increase in the accuracy of road surface condition determination as well as an increase in computing speed by performing an appropriate path limitation, a chronological waveform of tire vibrations detected by an acceleration sensor is windowed by a windowing means with a time T to extract a chronological waveform of the tire vibrations of each time window and to calculate a feature vector Xi for each time window; thereafter, when a kernel function KA (X, Y) is calculated from the feature vector Xi for each time window and a road surface feature vector Yj which is a feature vector for each time window calculated from a chronological waveform of tire vibrations that has been determined for each road surface condition calculated in advance, the kernel function is calculated after each of paths is weighted with a weighting parameter ω(i, j) using a chronological waveform length corresponding value in the chronological waveform of tire vibrations at the time of measurement, and a chronological waveform length corresponding value in the previously determined chronological waveform of tire vibrations. |
