Road surface state estimating apparatus, road surface friction state estimating apparatus, road surface state physical quantity calculating apparatus, and road surface state announcing apparatus

A road surface friction state estimating apparatus comprising:

• a detector configured to detect a feature quantity indicating a road surface state;
• a storage device configured to store road surface friction states that are friction states between road surfaces and a tire in such a manner that the road surface friction states are correlated with a plurality of feature quantities indicating different road surface states, respectively;
• an estimating device configured to estimate a road surface friction state of the road surface, the road surface corresponding to the feature quantity which is detected by the detector, on the basis of the feature quantities detected by the detector and the road surface friction states stored in the storage device;
• and
• a corrector configured to correct a road surface friction state stored in the storage device on the basis of a pre-detected road surface friction state of the road surface, the road surface corresponding to the feature quantity which is detected by the detector, and the road surface friction state estimated by the estimating device.

A road surface friction state estimating apparatus comprising:

• a first detector configured to detect feature quantity indicating a road surface state of a road surface on which a vehicle is running;
• a second detector configured to detect a feature quantity indicating a road surface state of a forward road surface obtained by shooting the forward road surface with a camera;
• a synchronizer configured to synchronize a feature quantity detected by the second detector with the feature quantities detected by the first detector of a road surface ,the road surface corresponding to the feature quantity which was detected by the second detector;
• a storage device configured to store road surface friction states that are friction states between road surfaces and a tire in such a manner that the road surface friction states are correlated with a plurality of feature quantities indicating different road surface states, respectively;
• and
• an estimating device configured to estimate a road surface friction state of the road surface ,the road surface corresponding to the feature quantity which is detected by the first detector, on the basis of the feature quantity detected by the first detector, the feature quantity detected by the second detector and synchronized by the synchronizer, and the road surface friction states stored in the storage device.

A road surface state physical quantity calculating apparatus comprising:

• a detector configured to detect at least one of saturation information, luminance infonnation and hue information of a forward road surface on which a vehicle will run;
• and
• a calculator configured to calculate a road surface state physical quantity on the basis of at least one of saturation information, luminance information and hue information of the forward road surface detected by the detector and a parameter to be used for calculating a road surface state physical quantity indicating a road surface state,
• wherein the calculator corrects the parameter on the basis of at least one of saturation information, luminance information and hue information of the forward road surface detected by the detector, and calculates a road surface state physical quantity indicating a road surface state on the basis of the corrected parameter and at least one of saturation information, luminance information and hue information of the forward road surface detected by the detector.

A road surface state estimating apparatus comprising:

• a storage device configured to store road surface state physical quantities determined on the basis of at least one of saturation information, luminance information and hue information and indicating road surface states of a plurality of road surfaces, respectively, in such a manner that the road surface state physical quantities are correlated with the respective road surface states;
• a detector configured to detect at least one of saturation information, luminance information and hue information of a forward road surface;
• and
• an estimating device for estimating a road surface state of the forward road surface on the basis of at least one of saturation information, luminance information and hue information of the forward road surface detected by the detector and the road surface state physical quantities stored in the storage device.

A road surface state announcing apparatus comprising:

• a current road surface state detector configured to detect a road surface state of a current road surface on which a vehicle mounted is running;
• a forward road surface state detector configured to detect a road surface state of a forward road surface;
• and
• an announcing device configured to compare the road surface state of the current road surface detected by the current road surface state detector and the road surface state of the forward road surface detected by the forward road surface state detector, and for making an announcement about a post-variation road surface state if one of the road surface state of the current road surface and the road surface state of the forward road surface has varied.

A road surface state announcing apparatus comprising:

• a current road surface state detector configured to detect a road surface state of a current road surface on which a vehicle is running;
• a forward road surface state detector confianred to detect a road surface state of a forward road surface;
• a synchronizer configured to synchronize a road surface state of a forward road surface detected by the forward road surface state detector with the road surface state of the current road surface detected by the current road surface state detector;
• and
• an announcing device configured to make an announcement about a road surface state of the current road surface on the basis of the road surface state of the current road surface detected by the current road surface state detector and the road surface state of the forward road surface detected by the forward road surface state detector and synchronized by the synchronizer with the road surface state of the current road surface detected by the current road surface state detector.

A road surface friction state estimating apparatus comprising:

• a road surface state detector configured to detect a road surface state of a road surface on which a vehicle in running;
• a road surface friction state estimating device configured to estimate a road surface friction state as a friction state between the road surface and a tire of the vehicle on the basis of a wheel rotation speed, front-rear acceleration, and lateral acceleration;
• and
• a final road surface friction state estimating device configured to estimate a final road surface friction state on the basis of the road surface state detected by the road surface state detector and the road surface friction state estimated by the road surface friction state estimating device.

A road surface state estimating apparatus comprising:

• a tire-generated sound detector configured to detect a tire-generated sound that is generated from a tire while a vehicle is running;
• a wheel rotation speed detector configured to detect a wheel rotation speed;
• a storage device configured to store a relationships between feature quantities corresponding to tire-generated sound sources and a wheel rotation speed in such a manner that the sets of coefficients are correlated with a plurality of road surface states, respectively;
• and
• an estimating device configured to estimate a road surface state on the basis of the tire-generated sound detected by the tire-generated sound detector, the wheel rotation speed detected by the wheel rotation speed detector, and the coefficients stored in the storage device,
• wherein the calculator calculates at least one feature quantity corresponding to a road surface state and tire-generated sound source by calculating correlation values of a waveform of the tire-generated sound detected by the tire-generated sound detector and at least one fundamental waveform having a predetermined length.