Brake control method and system

• US 8,070,237 B2
• Filed: 01/24/2006
• Issued: 12/06/2011
• Est. Priority Date: 01/24/2006
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Bosch Corporation (Robert Bosch GmbH)
• Original Assignee: Bayerische Motoren Werke AG, Bosch Corporation (Robert Bosch GmbH)
• Inventors: Ogawa, Takahiro, Hamm, Markus, Westerfeld, Helge
• Primary Examiner(s): Schwartz, Christopher P
• Application Number:
  US12/161,367
• Publication Number:
  US 20100225158A1
• Time in Patent Office: 2,142 Days
• Field of Search: 303/9.64, 303/138, 303/158, 303/163, 303/174, 303/137, 701/70, 701/71, 701/78, 701/79, 701/83
• US Class Current: 303/9.64
• CPC Class Codes: B60T 2240/06 Wheel load; Wheel lift
• CPC Class Codes: B60T 8/1706 for single-track vehicles, e.g. motorcycles
• CPC Class Codes: B60T 8/1766 Proportioning of brake forces according to vehicle axle loads, e.g. front to rear of vehicle
• CPC Class Codes: B60T 8/261 specially adapted for use in motorcycles
• CPC Class Codes: B60T 8/3225 Systems specially adapted for single-track vehicles, e.g. motorcycles B60T8/3235 takes precedence

Abstract

To predictively determine the occurrence of rear wheel lifting before actual lifting of a rear wheel occurs and enable control of brake force.

Vehicle body deceleration is computed on the basis of wheel velocities obtained by wheel velocity sensors 45 and 46 (S102), and when it is determined that that computed value exceeds a predetermined value K1 (S104), then the pressure of a front wheel cylinder 3 is reduced by a predetermined pressure and held at that reduced pressure (S106), and when it is determined that vehicle body deceleration has fallen below a value that is, for example, lower by a predetermined value α than the predetermined value K1 (S108), then the state of holding of the pressure of the front wheel cylinder 3 is released (S110) and brake control returns to normal brake control.

Claims

1. A two-wheeled motor vehicle brake control system configured to be capable of transmitting oil pressure arising in a front brake master cylinder in response to operation of a first brake operator to a front wheel cylinder via an oil pressure system, capable of transmitting oil pressure arising in a rear brake master cylinder in response to operation of a second brake operator to a rear wheel cylinder via an oil pressure system, and capable of discharging brake fluid of the front wheel cylinder to a front reservoir as desired,

wherein the brake control system is configured to

determine whether or not the value of a predetermined parameter that has been preselected as an index for predicting the potential for lifting of a rear wheel exceeds a first predetermined value,

determine that the potential for lifting of the rear wheel is large when the value of the predetermined parameter exceeds the first predetermined value and control generation of brake force by the front wheel cylinder, and

next determine whether or not the value of the predetermined parameter has fallen below a second predetermined value and, when it is determined that the predetermined parameter has fallen below said second predetermined value, release the control of the brake force,

wherein the second predetermined value is a value that is lower than the first predetermined value by a predetermined value,

wherein the control of the brake force is performed by reducing, by a predetermined pressure, the pressure of the front wheel cylinder and holding the pressure of the wheel cylinder at that reduced pressure, and

wherein the predetermined parameter is an amount of change in the pressure of the front wheel cylinder.

2. The two-wheeled motor vehicle brake control system of claim 1, wherein the control of the brake force is performed by holding the pressure of the front wheel cylinder at the pressure when it is determined that the predetermined parameter exceeds the first predetermined value.

3. A two-wheeled motor vehicle brake control program that is executed in a two-wheeled motor vehicle brake control system configured to be capable of transmitting oil pressure arising in a front brake master cylinder in response to operation of a first brake operator to a front wheel cylinder via an oil pressure system, capable of transmitting oil pressure arising in a rear brake master cylinder in response to operation of a second brake operator to a rear wheel cylinder via an oil pressure system, and capable of discharging brake fluid of the front wheel cylinder to a front reservoir as desired,

wherein the brake control program includes

a first step of determining whether or not the value of a predetermined parameter that has been preselected as an index for predicting the potential for lifting of a rear wheel exceeds a first predetermined value,

a second step of determining that the potential lifting of the rear wheel is large when the value of the predetermined parameter exceeds the first predetermined value at the first step, causing brake fluid to be discharged to the front reservoir such that the pressure of the front wheel cylinder is reduced by a predetermined pressure and, when the pressure of the front wheel cylinder has been reduced by a predetermined pressure, causing the pressure of the front wheel cylinder to be held at that pressure,

a third step of determining whether or not the value of the predetermined parameter has fallen below a value that is lower by a predetermined value than the first predetermined value, and

a fourth step of releasing holding of the pressure of the front wheel cylinder when it is determined in the third step that the predetermined parameter has fallen below the value that is lower by a predetermined value than the first predetermined value,

wherein the predetermined parameter is an amount of change in the pressure of the wheel cylinder that applies brake force to the front wheel.

4. A two-wheeled motor vehicle brake control program that is executed in a two-wheeled motor vehicle brake control system configured to be capable of transmitting oil pressure arising in a front brake master cylinder in response to operation of a first brake operator to a front wheel cylinder via an oil pressure system, capable of transmitting oil pressure arising in a rear brake master cylinder in response to operation of a second brake operator to a rear wheel cylinder via an oil pressure system, and capable of discharging brake fluid of the front wheel cylinder to a front reservoir as desired,

wherein the brake control program includes

a first step of determining whether or not the value of a predetermined parameter that has been preselected as an index for predicting the potential for lifting of a rear wheel exceeds a first predetermined value,

a second step of determining that the potential lifting of the rear wheel is large when the value of the predetermined parameter exceeds the first predetermined value at the first step, causing the pressure of the front wheel cylinder to be held at the pressure at that time,

a third step of determining whether or not the value of the predetermined parameter has fallen below a value that is lower by a predetermined value than the first predetermined value, and

a fourth step of releasing holding of the pressure of the front wheel cylinder when it is determined in the third step that the predetermined parameter has fallen below the value that is lower by a predetermined value than the first predetermined value,

wherein the predetermined parameter is an amount of change in the pressure of the wheel cylinder that applies brake force to the front wheel.

5. A two-wheeled motor vehicle brake control method comprising:

determining whether or not the value of one kind of parameter selected beforehand as an index for predicting the potential for lifting of a rear wheel exceeds a first predetermined value;

determining that the potential for lifting of the rear wheel is large when the value of the one kind of parameter selected beforehand exceeds the first predetermined value and controlling generation of brake force;

next determining whether or not the value of the one kind of parameter selected beforehand has fallen below a second predetermined value and, when it is determined that the one kind of parameter selected beforehand has fallen below the second predetermined value, releasing the control of the brake force;

wherein the second predetermined value is a value that is lower than the first predetermined value by a predetermined value;

wherein the control of the brake force is performed by holding the pressure of a wheel cylinder that applies brake force to a front wheel at the pressure when it is determined that the one kind of parameter selected beforehand exceeds the first predetermined value;

wherein the one kind of parameter selected beforehand is an amount of change in the pressure of the wheel cylinder that applies brake force to the front wheel; and

wherein the amount of change in the pressure of the wheel cylinder that applies brake force to the front wheel is the only parameter used in the brake control method.

6. A two-wheeled motor vehicle brake control method comprising:

determining whether or not the value of one kind of parameter selected beforehand as an index for predicting the potential for lifting of a rear wheel exceeds a first predetermined value;

determining that the potential for lifting of the rear wheel is large when the value of the one kind of parameter selected beforehand exceeds the first predetermined value and controlling generation of brake force;

next determining whether or not the value of the one kind of parameter selected beforehand has fallen below a second predetermined value and, when it is determined that the one kind of parameter selected beforehand has fallen below the second predetermined value, releasing the control of the brake force;

wherein the second predetermined value is a value that is lower than the first predetermined value by a predetermined value;

wherein the control of the brake force is performed by reducing, by a predetermined pressure, the pressure of a wheel cylinder that applies brake force to a front wheel and holding the pressure of the wheel cylinder at that reduced pressure;

wherein the one kind of parameter selected beforehand is an amount of change in the pressure of the wheel cylinder that applies brake force to the front wheel; and

wherein the amount of change in the pressure of the wheel cylinder that applies brake force to the front wheel is the only parameter used in the brake control method.

7. A two-wheeled motor vehicle brake control method comprising:

determining whether or not the value of one kind of parameter selected beforehand as an index for predicting the potential for lifting of a rear wheel exceeds a first predetermined value;

determining that the potential for lifting of the rear wheel is large when the value of the one kind of parameter selected beforehand exceeds the first predetermined value and controlling generation of brake force;

next determining whether or not the value of the one kind of parameter selected beforehand has fallen below a second predetermined value and, when it is determined that the one kind of parameter selected beforehand has fallen below the second predetermined value, releasing the control of the brake force;

wherein the second predetermined value is a value that is lower than the first predetermined value by a predetermined value;

wherein the control of the brake force is performed by holding the pressure of a wheel cylinder that applies brake force to a front wheel at the pressure when it is determined that the one kind of parameter selected beforehand exceeds the first predetermined value;

wherein the one kind of parameter selected beforehand is an amount of change in the pressure of the wheel cylinder that applies brake force to the front wheel; and

wherein the amount of change in the pressure of the wheel cylinder that applies brake force to the front wheel is the only parameter used in the brake control method.