Method of braking force distribution control for a vehicle hydraulic device

A method of determining when and on which rear wheel brakes to activate braking force distribution control in a hydraulic brake system of a vehicle, which system comprises:

• a hydraulic unit comprising a wheel speed sensor for detecting wheel speed, a main hydraulic circuit connecting a master cylinder to four wheel cylinders via inlet valves, and an auxiliary hydraulic circuit connecting the wheel cylinders to an auxiliary reservoir via outlet valves;
• a means for detecting acceleration of movement, and
• an electronic control device which controls the hydraulic unit;
• wherein the method comprises the steps of:
• determining wheel speed of at least two rear wheels;
• determining whether to apply braking force distribution control to an inner rear wheel or outer rear wheel;
• if the rear wheel subject to control is an outer rear wheel, applying braking force distribution control to the outer rear wheel when a deceleration threshold value is increased according to acceleration in a lateral direction, and the absolute value of vehicle deceleration exceeds the deceleration threshold value;
• and then a slip threshold value is increased according to a difference between inner wheel speed and outer wheel speed, and the rear wheel slip ratio exceeds the slip threshold value;
• and
• if the rear wheel subject to control is an inner rear wheel, applying braking force distribution control to the outer rear wheel when a deceleration threshold value is decreased according to acceleration in a lateral direction, and the absolute value of vehicle deceleration exceeds the deceleration threshold value;
• and then a slip threshold value is decreased according to a difference between inner wheel speed and outer wheel speed, and the rear wheel slip ratio exceeds the slip threshold value.

A method of determining when and on which rear wheel brakes to activate braking force distribution control in a hydraulic brake system of a vehicle, which system comprises:

• a hydraulic unit comprising a wheel speed sensor for detecting wheel speed, a main hydraulic circuit connecting a master cylinder to four wheel cylinders via inlet valves, and an auxiliary hydraulic circuit connecting the wheel cylinders to an auxiliary reservoir via outlet valves;
• a means for detecting acceleration of movement;
• and
• an electronic control device which controls the hydraulic unit;
• wherein the method comprises the steps of:
• determining whether to apply braking force distribution control to an inner rear wheel or outer rear wheel;
• if the rear wheel subject to control is an outer rear wheel, applying braking force distribution control to the outer rear wheel when an absolute value of front wheel axle deceleration minus an absolute value of outer rear wheel deceleration is smaller than a correction value relative to lateral acceleration;
• and
• if the rear wheel subject to control is an inner rear wheel, applying braking force distribution control to the inner rear wheel when an absolute value of front wheel axle deceleration minus an absolute value of outer rear wheel deceleration is smaller than a correction value relative to lateral acceleration.

A method of determining when and on which rear wheel brakes to activate braking force distribution control in a hydraulic brake system of a vehicle, which system comprises:

• a hydraulic unit comprising a wheel speed sensor for detecting wheel speed, a main hydraulic circuit connecting a master cylinder to four wheel cylinders via inlet valves, and an auxiliary hydraulic circuit connecting the wheel cylinders to an auxiliary reservoir via outlet valves;
• a means for detecting acceleration of movement;
• and
• an electronic control device which controls the hydraulic unit;
• wherein the method comprises the steps of:
• determining whether to apply braking force distribution control to an inner rear wheel or outer rear wheel;
• if the rear wheel subject to control is an outer rear wheel, applying braking force distribution control to the outer rear wheel when an absolute value of front wheel axle deceleration minus an absolute value of rear wheel deceleration is smaller than a correction value relative to a lateral direction;
• and then a slip threshold value is increased according to a difference between inner wheel speed and outer wheel speed, and the rear wheel slip ratio exceeds the slip threshold value, and
• if the rear wheel subject to control is an inner rear wheel, applying braking force distribution control to the outer rear wheel when an absolute value of front wheel axle deceleration minus an absolute value of rear wheel deceleration is smaller than a correction value relative to lateral acceleration;
• and then a slip threshold value is decreased according to a difference between inner wheel speed and outer wheel speed, and the rear wheel slip ratio exceeds the slip threshold value.