Method of braking force distribution control for a vehicle hydraulic device
First Claim
1. 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 a vehicle movement; and
an electronic control device which controls the hydraulic unit;
wherein the method comprises the steps of;
independently determining the speed of rear wheels of the vehicle;
determining whether to apply braking force distribution control to an inner rear wheel or an outer rear wheel;
if the rear wheel subject to control stands an outer rear wheel, applying braking force distribution control to the outer rear wheel when a deceleration threshold value is increased according to acceleration of a vehicle lateral direction and the absolute value of vehicle deceleration exceeds the deceleration threshold value; and
if the rear wheel subject to control is an inner rear wheel, applying braking force distribution control to the inner rear wheel when a deceleration threshold value is increased according to acceleration of a vehicle lateral direction and the absolute value of vehicle deceleration exceeds the deceleration threshold value.
1 Assignment
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Accused Products
Abstract
It is an object of this invention to provide a method for when and on which wheel to initiate braking force distribution. In a brake hydraulic device for a motor vehicle, a rear wheel subject to control is an inner or outer wheel is checked; if the outer wheel is to be controlled, deceleration threshold value is increased according to the lateral acceleration, and if the absolute value of the vehicle deceleration exceeds the deceleration threshold value, the braking distribution control is operated on the rear wheel; and if the inner wheel is to be controlled, deceleration threshold value is decreased according to the lateral acceleration, and if the absolute value of vehicle deceleration exceeds the deceleration threshold value, the braking distribution control is operated on the rear wheel.
61 Citations
8 Claims
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1. 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:
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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 a vehicle movement; and
an electronic control device which controls the hydraulic unit;
wherein the method comprises the steps of;
independently determining the speed of rear wheels of the vehicle;
determining whether to apply braking force distribution control to an inner rear wheel or an outer rear wheel;
if the rear wheel subject to control stands an outer rear wheel, applying braking force distribution control to the outer rear wheel when a deceleration threshold value is increased according to acceleration of a vehicle lateral direction and the absolute value of vehicle deceleration exceeds the deceleration threshold value; and
if the rear wheel subject to control is an inner rear wheel, applying braking force distribution control to the inner rear wheel when a deceleration threshold value is increased according to acceleration of a vehicle lateral direction and the absolute value of vehicle deceleration exceeds the deceleration threshold value. - View Dependent Claims (2)
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3. 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:
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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.- View Dependent Claims (4)
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5. 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:
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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. - View Dependent Claims (6)
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7. 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:
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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, andif 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.- View Dependent Claims (8)
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Specification