Brake control system for an automotive vehicle

A method for controlling a brake system of an automotive vehicle comprising the steps of:

• determining wheel r.p.m. and generating a first signal indicative of the determined wheel r.p.m.;
• determining a deceleration rate of the wheel based on the determined wheel r.p.m.;
• comparing the determined deceleration rate with a predetermined reference value and generating a second signal when the determined deceleration rate becomes equal to or greater than the predetermined reference value;
• calculating a deceleration coefficient based on said first signal value;
• calculating a decelerating wheel r.p.m. based on said deceleration coefficient and said first signal value;
• and
• subtracting said deceleration coefficient from the value of said first signal at the time said second signal is produced to obtain said decelerating wheel r.p.m.

An anti-skid brake control system for an automotive vehicle for controlling application and release of brake pressure to a wheel cylinder in a hydraulic automotive brake circuit, comprising:

• first means for detecting wheel r.p.m. and producing a first signal having a value proportional to the wheel r.p.m.;
• second means for calculating a deceleration rate of the wheel r.p.m. based on variation of said first signal value and producing a second signal when said deceleration rate becomes equal to or greater than a first threshold;
• third means for calculating a deceleration coefficient based on variation of said first signal value during an interval between occurrences of said second signals and on the length of said interval and for calculating a target wheel r.p.m. based on said deceleration coefficient and on a value of said first signal value at the time of occurrence of said second signal, said third means producing a third signal representative of said target wheel r.p.m. and comparing said third signal value with said first signal to produce a control signal when said first signal value becomes equal to or less than said third signal value;
• and
• fourth means, responsive to said control signal, for releasing said brake pressure.

A brake control system for controlling application and release of brake pressure to a wheel of an automotive vehicle to prevent the vehicle from skidding, comprising:

• wheel speed sensing means for determining wheel speed for a braked wheel and producing a first signal representative thereof;
• deceleration detecting means receiving said first signal for determining a condition wherein said wheel speed is decelerating at a rate equaling or exceeding a threshold and producing a second signal indicative thereof;
• target wheel speed determining means receiving and responsive to said first and second signals for generating a third signal representing a target wheel speed as a function of a deceleration rate averaged between occurrences of said second signal, including:
• sample and hold means sampling said first signal and, responsively to said second signal, for holding values of said first signal having a predetermined time relationship with said second signal;
• deceleration rate determining means for obtaining a difference between the held values of said first signal and dividing the difference thus obtained by the length of a time interval between the occurrences of said second signal to obtain an averaged deceleration rate for said wheel speed during said time interval and providing a fourth output signal indicative thereof;
• integrating means connected for receiving said output signal indicative of said averaged deceleration rate for producing a fifth output signal indicative of an integral of said averaged deceleration rate;
• subtracting means for obtaining a difference between said first signal and said fifth signal to produce a sixth signal representing a target wheel speed for comparison with wheel speed during a next cycle of operation of the system, and control means responsive to said sixth signal
• and to said first signal for releasing brake pressure to said wheel when the wheel speed represented by said first signal drops below the target speed therefor represented by said sixth signal.

A brake control system for controlling application and release of brake pressure to a wheel of an automotive vehicle to prevent the vehicl from skidding, comprising:

• wheel speed sensing means for determining wheel speed for a braked wheel and producing a first signal representative thereof;
• deceleration detection means receiving said first signal for determining a condition wherein said wheel speed is decelerating at a rate equalling or exceeding a threshold and producing a second signal indicative thereof;
• target wheel speed determining means receiving and responsive to said first and second signals for generating a third signal representing a target wheel speed, including
• reference signal generating means responsive to said deceleration detecting means for generating a plurality of signals representing a plurality of decelerating rates,
• decelerating rate determining means receiving said first and second signals and said plurality of signals for selecting one of said decelerating rates by comparing a value of said first signal obtained at one occurrence of said second signal with a value obtained by subtracting said plurality of decelerating rates from a value of said first signal obtained at a previous occurrence of said second signal, and
• means responsive to said selected decelerating rate for providing a target wheel speed for said first signal upon a subsequent occurrence of said second signal.