Vehicle body speed estimating method in anti-lock control system for vehicle

A method for estimating a vehicle body speed in an anti-lock control system for a vehicle for controlling the braking pressure on each of the wheels by estimating the vehicle body speed based on a wheel rotational speed detected in a speed sensor and determining a slit rate of each wheel based on the estimated vehicle body speed, said method comprising the steps of:

• calculating a first vehicle body speed based on wheel rotational speeds detected in speed sensors for each of a plurality of object wheels;
• determining a highest speed value of the wheel rotational speeds detected in the speed sensors of the plurality of speed sensors;
• correcting the highest speed value of speeds with a correction value based on a difference between an inner wheel speed and an outer wheel speed during turning of the vehicle;
• calculating a second vehicle body speed for each of the plurality of object wheels based on the corrected highest speed value;
• and
• selecting a higher one of the first and second vehicle body speeds as an estimated vehicle body speed for use in anti-lock control of each of the plurality of object wheels.

A method for estimating a vehicle body speed in an anti-lock control system for a vehicle for controlling the braking pressure for wheels by estimating the vehicle body speed on the basis of a wheel rotational speed detected in a speed sensor and judging a slip rate of the wheel on the basis of the estimated vehicle body speed, said method comprising the steps of:

• calculating first vehicle body speeds at least for a front wheel side and a rear wheel side, respectively, based on wheel rotational speeds detected in speed sensors for the vehicle wheels;
• selecting a higher one of at least two wheels speeds derived from the front wheel side and the rear wheel side, respectively;
• correcting said selected higher wheel speed by a correction value based on a difference in speed between inner and outer wheels during turning of the vehicle to calculate second vehicle body speeds at least for the front wheel side and the rear wheel side, respectively;
• selecting a higher one of said first and second vehicle body speeds associated with respective wheels as an estimated vehicle body speed for the associated wheel to be used in an anti-lock control for the wheel.