Road surface condition-detecting system and anti-lock brake system employing same

A road surface condition-detecting system for a vehicle having wheels, which detects a condition of a road surface on which said vehicle is traveling, comprising:

• road noise-detecting means arranged in the vicinity of at least one of said wheels of said vehicle for detecting road noise generated from said at least one of said wheels;
• determining means for determining said condition of said road surface, based on said road noise detected by said road noise-detecting means;
• disturbance-detecting means for detecting a disturbance to said road noise;
• and
• correcting means for correcting said road noise detected by said road noise-detecting means by said disturbance detected by said disturbance-detecting means.

A road surface condition-detecting system for a vehicle having wheels and an audio equipment, which detects a condition of a road surface on which said vehicle is traveling, comprising:

• road noise-detecting means arranged in the vicinity of at least one of said wheels of said vehicle for detecting road noise generated from said at least one of said wheels;
• determining means for determining said condition of said road surface, based on said road noise detected by said road noise-detecting means;
• audio output-detecting means for detecting an output signal from said audio equipment;
• and
• correcting means for correcting said road noise detected by said road noise-detecting means by said output signal detected by said audio output-detecting means.

A road surface condition-detecting system for a vehicle having wheels and an engine, which detects a condition of a road surface on which said vehicle is traveling, comprising:

• road noise-detecting means arranged in the vicinity of at least one of said wheels of said vehicle for detecting road noise generated from said at least one of said wheels;
• determining means for determining said condition of said road surface, based on said road noise detected by said road noise-detecting means;
• estimating means for detecting operating conditions of said engine, and for estimating exhaust noise, based on results of said detection of said operating conditions of said engine;
• and
• correcting means for correcting said road noise detected by said road noise-detecting means by said exhaust noise estimated by said estimating means.

A road surface condition-detecting system for a vehicle having wheels, which detects a condition of a road surface on which said vehicle is traveling, comprising:

• road noise-detecting means arranged in the vicinity of at least one of said wheels of said vehicle for detecting road noise generated from said at least one of said wheels;
• first determining means for determining said condition of said road surface, based on said road noise detected by said road noise-detecting means at regular time intervals;
• and
• second determining means for determining a present state of said condition of said road surface, based on at least two consecutive outputs from said first determining means.

A road surface condition-detecting system for a vehicle having wheels, which detects a condition of a road surface on which said vehicle is traveling, comprising:

• road noise-detecting means arranged in the vicinity of at least one of said wheels of said vehicle for detecting road noise generated from said at least one of said wheels;
• means for classifying said condition of said road surface on which said vehicle is to travel into a plurality of types, and for providing a plurality of exclusive neural networks for respective ones of said plurality of types of said condition of said road surface;
• and
• determining means for determining said condition of said road surface, based on said road noise detected by said road noise-detecting means, by the use of said plurality of exclusive neural networks.

A road surface condition-detecting system for a vehicle having wheels, which detects a condition of a road surface on which said vehicle is traveling, comprising:

• road noise-detecting means arranged in the vicinity of at least one of said wheels of said vehicle for detecting road noise generated from said at least one of said wheels;
• vehicle speed-detecting means for detecting a speed of said vehicle;
• means for classifying said speed of said vehicle into a plurality of ranges, and for providing a plurality of exclusive neural networks for respective ones of said plurality of ranges of said speed of said vehicle;
• and
• determining means for selecting one of said plurality of exclusive neural networks according to said speed of said vehicle detected by said vehicle speed-detecting means, and for determining said condition of said road surface, based on said road noise detected by said road noise-detecting means, by the use of said selected one of said plurality of exclusive neural networks.

A road surface condition-detecting system for a vehicle having wheels, which detects a condition of a road surface on which said vehicle is traveling, comprising:

• setting means for setting in advance upper limit values and lower limit values of a range of a sound pressure level of said road noise to be generated from at least one of said wheels, respectively, for predetermined frequency components;
• road noise-detecting means arranged in the vicinity of said at least one of said wheels of said vehicle for detecting road noise generated from said at least one of said wheels;
• frequency analysis means for extracting sound pressure levels of predetermined frequency components of said road noise, from said road noise detected by said road noise-detecting means;
• selecting/normalizing means for selecting upper limit values and lower limit values corresponding to respective ones of said predetermined frequency components of said sound pressure levels extracted by said frequency analysis means, from said upper limit values and said lower limit values set, respectively, for said predetermined frequency components by said setting means, and for normalizing said sound pressure levels extracted by said frequency analysis means within respective sound pressure level ranges defined by said selected upper limit values and said lower limit values;
• and
• determining means for inputting the normalized sound pressure levels to a neural network, and for determining said condition of said road surface, based on an output from said neural network.

A road surface condition-detecting system for a vehicle having wheels, which detects a condition of a road surface on which said vehicle is traveling, comprising:

• setting means for setting in advance upper limit values and lower limit values of a range of a sound pressure level of said road noise to be generated from at least one of said wheels, respectively, for predetermined vehicle speeds;
• road noise-detecting means arranged in the vicinity of said at least one of said wheels of said vehicle for detecting road noise generated from said at least one of said wheels;
• vehicle speed-detecting means for detecting a speed of said vehicle;
• frequency analysis means for extracting sound pressure levels of predetermined frequency components of said road noise, from said road noise detected by said road noise-detecting means;
• selecting/normalizing means for selecting an upper limit value and a lower limit value of said range of said sound pressure level corresponding to said vehicle speed detected by said vehicle speed-detecting means, from said upper limit values and said lower limit values set, respectively, for said predetermined speeds of said vehicle by said setting means, and for normalizing said sound pressure levels extracted by said frequency analysis means within respective sound pressure level ranges defined by said selected upper limit values and said lower limit values;
• and
• determining means for inputting the normalized sound pressure levels to a neural network, and for determining said condition of said road surface, based on an output from said neural network.