ROAD SURFACE STATE ESTIMATING METHOD, ROAD SURFACE STATE ESTIMATING TIRE, ROAD SURFACE STATE ESTIMATING DEVICE, AND VEHICLE CONTROL DEVICE

摘要

Vibrations in the circumferential direction and in the widthwise direction are detected on a road surface state estimating tire (10) having an acceleration sensor (11) and a signal processing device (12). The vibration waveform data detected is divided into three area data of an area to be trod, a trod area and a kick-off area. The vibration levels of the area to be trod and the trod area are individually extracted, and the vibration component in a low-frequency band and the vibration component in a high-frequency band are individually extracted from the vibration levels of the individual areas. The vibration level ratios (R) of the vibration components are individually calculated. On the vehicle side, the state of the road surface, on which the vehicle is running, is estimated on the basis of a map (32M) dictating the relations among the vibration level ratio (R) calculated, the vibration level ratio (R) of the tire vibrations stored in storage means (32), and the state of the road surface, so that the road surface state can be precisely estimated, even in case the temperature or the speed changes.