Method for estimating vehicular running state, vehicular running state estimating device, vehicle control device, and tire wheel

A vehicle running state estimation method comprising;

• detecting a vibration level of a portion below a spring of a running vehicle;
• and
• estimating the running state of the vehicle by determining a degree of slipperiness of a road surface on which the vehicle is running and a running state of each tire,
• wherein said determining is based on the detected vibration level, and
• wherein the frequency of the detected vibration level is analyzed, at least two vibration levels at different frequency bands are calculated, an operation is carried out on the at least two calculated vibration levels, and the degree of slipperiness of the road surface is estimated from computed value.

A vehicle running state estimation method comprising:

• detecting a vibration level of a portion below a spring of a running vehicle;
• and
• estimating the running state of the vehicle by determining a condition of a road surface on which the vehicle is running and a running state of each tire,
• wherein said determining is based on the detected vibration level, and,
• wherein vibration levels of at least two points of a portion below the spring with a buffer member interposed therebetween are detected to calculate a vibration transmission level of the portion below the spring between the two points at a predetermined frequency band;
• and the condition of the road surface is estimated from the calculated vibration transmission level.

A vehicle running state estimation apparatus comprising:

• means of detecting a vibration level of a portion below a spring of a running vehicle;
• means of calculating a vibration level at a predetermined frequency band by analyzing frequency of the detected vibration level;
• and
• road surface condition estimation means for estimating a condition of the road surface on which the vehicle is running by comparing the calculated vibration level with the master curve which is the vibration level detected through running on a road having a predetermined road surface condition,
• wherein the running state of the vehicle is estimated based on the condition of the road surface from the road surface condition estimation means.

A vehicle running state estimation apparatus comprising:

• means of detecting a vibration level of a portion below a spring of a running vehicle;
• and
• road surface condition estimation means for estimating a degree of slipperiness of a road surface from a value obtained by carrying out an operation on at least two vibration levels at different frequency bands by analyzing the frequency of the detected vibration level,
• wherein the running state of the vehicle is estimated based on the degree of slipperiness of the road surface received from the road surface condition estimation means.

A vehicle running state estimation apparatus for estimating a running state of a vehicle based on a condition of a road surface comprising:

• means of detecting vibration levels of at least two points on a portion below a spring of the running vehicle with a buffer member being interposed therebetween;
• means of calculating a vibration transmission level at a predetermined frequency band between said at least two vibration detection points;
• and
• road surface condition estimation means for estimating a condition of the road surface on which the vehicle is running from the calculated vibration transmission level.

A vehicle running state estimation apparatus comprising:

• means of detecting a vibration level of a portion below a spring of a running vehicle;
• means of calculating a vibration level at a predetermined frequency band by analyzing frequency of the detected vibration level;
• and
• road surface condition estimation means for estimating a degree of slipperiness of the road surface on which the vehicle is running from the calculated vibration level,
• wherein the running state of the vehicle is estimated based on the degree of slipperiness of the road surface received from the road surface condition estimation means, and
• wherein a road surface friction coefficient μ at a time of running the vehicle is estimated based on a relationship between a surface friction coefficient μ obtained from braking distances of the vehicle under various road conditions at different speeds and at least one of the calculated vibration level at said predetermined frequency band and a calculated vibration transmission level.

A vehicle running state estimation apparatus comprising;

• means of detecting a vibration level of a portion below a spring of a running vehicle;
• means of calculating a vibration level at a predetermined frequency band by analyzing frequency of the detected vibration level;
• and
• road surface condition estimation means for estimating a degree of slipperiness of the road surface on which the vehicle is running from the calculated vibration level,
• wherein the running state of the vehicle is estimated based on the degree of slipperiness of the road surface received from the road surface condition estimation means, and
• wherein the frequency band is a band including frequency of natural vibration of a tire tread land portion.

A vehicle running state estimation apparatus comprising:

• means of detecting a vibration level of a portion below a spring of a running vehicle;
• means of calculating a vibration level at a predetermined frequency band by analyzing frequency of the detected vibration level;
• and
• road surface condition estimation means for estimating a degree of slipperiness of the road surface on which the vehicle is running from the calculated vibration level,
• wherein the running state of the vehicle is estimated based on the degree of slipperiness of the road surface received from the road surface condition estimation means, and
• wherein a threshold value is set for the vibration level, and the surface of the road is estimated to be in a low friction condition when the calculated vibration level exceeds the threshold value.

A vehicle running state estimation apparatus for estimating running state of a vehicle based on road surface conditions, the estimation apparatus comprising:

• means of detecting a vibration level of a portion below a spring of a running vehicle;
• means of computing waveform of time changes in the vibration level;
• and
• road surface condition estimation means for estimating a condition of a road surface on which the vehicle is running from the vibration level at a predetermined position of the waveform or for a predetermined time range.