Single channel roll stability system

• US 20070138865A1
• Filed: 12/15/2005
• Published: 06/21/2007
• Est. Priority Date: 12/15/2005
• Status: Active Grant

• Current Assignee: Bendix Commercial Vehicle Systems LLC (Estate of Heinz Hermann Thiele)
• Original Assignee: Bendix Commercial Vehicle Systems LLC (Estate of Heinz Hermann Thiele)
• Inventors: Amato, William
• Granted Patent: US 8,191,975 B2
• Time in Patent Office: Days
• US Class Current: 303/191
• CPC Class Codes: B60T 2230/03 Overturn, rollover
• CPC Class Codes: B60T 8/1708 for lorries or tractor-trailer combinations
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60T 8/17554 specially adapted for enhancing stability around the vehicles longitudinal axle, i.e. roll-over prevention road vehicle drive control systems for roll-over prevention otherwise than by controlling a particular sub-unit B60W30/04
• CPC Class Codes: B60T 8/243 for roll-over protection

Abstract

A method and system for assessing and preventing overturn of a vehicle, the method and system being particularly suitable for use with commercial vehicles with brake systems typically used in North America, wherein a vehicle equipped with single brake pressure modulator is controlled to increase or decrease brake pressure, depending on braking state, to test vehicle wheel speed by response. If the vehicle wheel speed response indicates the inside wheels of the vehicle are off the ground or only lightly loaded, it may be assumed that the vehicle is approaching overturning. A braking intervention may be then executed by the single brake pressure modulator to prevent the incipient overturn event.

Claims

1. A method of assessing whether a vehicle equipped with a plurality of wheel brakes is about to overturn, the vehicle being equipped with a single brake pressure modulator arranged to control actuation of the vehicle brakes, comprising the acts of:

determining a lateral acceleration of the vehicle;

determining a rotational wheel speed of the vehicle wheels;

when the lateral acceleration exceeds a predetermined threshold, conducting a rotational wheel speed change test, wherein the test includes

if the vehicle is not being braked, applying a brake pressure to the vehicle brakes with the single brake pressure modulator, or

if the vehicle is being braked, lowering a brake pressure being applied by the single brake pressure modulator;

monitoring the wheel speed behaviour of the vehicle wheels on an inside side of the vehicle, said inside side being the side facing away from the lateral acceleration direction; and

determining based on monitored wheel speed behaviour whether the vehicle is about to overturn.

2. The method of claim 1, wherein in the overturn determination step, if the vehicle is not being braked, the vehicle is determined to be about to overturn when the wheel speed of the inside wheels one of reaches zero or decreases at a greater rate than the wheels on an outside side of the vehicle.

3. The method of claim 1, wherein in the overturn determination step, if the vehicle is being braked, the vehicle is determined to be about to overturn when the wheel speed of the inside wheels increases at a greater rate than the wheels on an outside side of the vehicle.

4. A method of preventing overturning of a vehicle equipped with a plurality of wheel brakes, the vehicle being equipped with a single brake pressure modulator arranged to control actuation of the vehicle brakes, comprising the acts of:

determining a lateral acceleration of the vehicle;

determining a rotational wheel speed of the vehicle wheels;

when the lateral acceleration exceeds a predetermined threshold, conducting a rotational wheel speed change test, wherein the test includes

if the vehicle is not being braked, applying a brake pressure to the vehicle brakes with the single brake pressure modulator, or

if the vehicle is being braked, lowering a brake pressure being applied by the single brake pressure modulator;

monitoring the wheel speed behaviour of the vehicle wheels on an inside side of the vehicle, said inside side being the side facing away from the lateral acceleration direction;

determining based on monitored wheel speed behaviour whether the vehicle is about to overturn; and

applying the vehicle brakes to decrease vehicle speed when it is determined that the vehicle is about to overturn.

5. The method of claim 4, wherein in the overturn determination step, if the vehicle is not being braked, the vehicle is determined to be about to overturn when the wheel speed of one of the inside wheels reaches zero or decreases at a greater rate than the wheels on an outside side of the vehicle.

6. The method of claim 4, wherein in the overturn determination step, if the vehicle is being braked, the vehicle is determined to be about to overturn when the wheel speed of the inside wheels increases at a greater rate than the wheels on an outside side of the vehicle.

7. A method of assessing whether a vehicle equipped with a plurality of wheel brakes is about to overturn, the vehicle being equipped with a single brake pressure modulator arranged to control actuation of all the vehicle brakes on at least one vehicle axle, comprising the acts of:

determining a lateral acceleration of the vehicle;

determining a rotational wheel speed of the vehicle wheels;

when the lateral acceleration exceeds a predetermined threshold, conducting a rotational wheel speed change test, wherein the test includes

if the vehicle is not being braked, applying a brake pressure to the vehicle brakes with the single brake pressure modulator, or

if the vehicle is being braked, lowering a brake pressure being applied by the single brake pressure modulator;

monitoring the wheel speed behaviour of the vehicle wheels on an inside side of the vehicle, said inside side being the side facing away from the lateral acceleration direction; and

determining based on monitored wheel speed behaviour whether the vehicle is about to overturn.

8. A vehicle overturn assessment system for assessing whether a vehicle equipped with a plurality of wheel brakes is about to overturn, comprising:

a vehicle lateral acceleration sensor;

a plurality of vehicle wheel speed sensors for sensing rotational wheel speed of at least one wheel on each lateral side of a vehicle;

a single brake pressure modulator arranged to control actuation of the vehicle wheel brakes; and

a control unit,

wherein the control unit is programmed to monitor signals generated by the lateral acceleration sensor and the wheel speed sensors, monitor whether the single brake pressure modulator is applying braking pressure, and command the single brake pressure modulator to apply braking pressure, and

wherein the control unit is programmed to assess whether a vehicle overturn event is about to occur by

determining whether a lateral acceleration sensed by the lateral acceleration sensor exceeds a predetermined threshold,

determining the rotational wheel speed of at least the at least one wheel on each lateral side of a vehicle,

conducting a rotational wheel speed change test when the lateral acceleration exceeds the predetermined threshold, wherein the test includes

if the vehicle is not being braked, applying a brake pressure to the vehicle brakes with the single brake pressure modulator, or

if the vehicle is being braked, lowering a brake pressure being applied by the single brake pressure modulator,

monitoring the wheel speed behaviour of at least the at least one wheel on an inside side of the vehicle, said inside side being the side facing away from the lateral acceleration direction, and

determining based on monitored wheel speed behaviour whether the vehicle overturn event is about to occur.

9. The vehicle overturn assessment system of claim 8, wherein the control unit is programmed such that when the vehicle is not being braked, the vehicle is determined to be about to overturn when the wheel speed of the at least one inside wheel reaches zero or decreases at a greater rate than the at least one wheel on an outside side of the vehicle.

10. The vehicle overturn assessment system of claim 8, wherein the control unit is programmed such that when the vehicle is being braked, the vehicle is determined to be about to overturn when the wheel speed of the at least one inside wheel increases at a greater rate than the at least one wheel on an outside side of the vehicle.

11. A vehicle overturn prevention system for assessing and preventing the overturn of a vehicle equipped with a plurality of wheel brakes, comprising:

a vehicle lateral acceleration sensor;

a plurality of vehicle wheel speed sensors for sensing rotational wheel speed of at least one wheel on each lateral side of a vehicle;

a single brake pressure modulator arranged to control actuation of the vehicle wheel brakes; and

a control unit,

wherein the control unit is programmed to monitor signals generated by the lateral acceleration sensor and the wheel speed sensors, monitor whether the single brake pressure modulator is applying braking pressure, and command the single brake pressure modulator to apply braking pressure, and

wherein the control unit is programmed to assess and prevent a vehicle overturn event by

determining whether a lateral acceleration sensed by the lateral acceleration sensor exceeds a predetermined threshold,

determining the rotational wheel speed of at least the at least one wheel on each lateral side of a vehicle,

conducting a rotational wheel speed change test when the lateral acceleration exceeds the predetermined threshold, wherein the test includes

if the vehicle is not being braked, applying a brake pressure to the vehicle brakes with the single brake pressure modulator, or

if the vehicle is being braked, lowering a brake pressure being applied by the single brake pressure modulator,

monitoring the wheel speed behaviour of at least the at least one wheel on an inside side of the vehicle, said inside side being the side facing away from the lateral acceleration direction,

determining based on monitored wheel speed behaviour whether the vehicle overturn event is about to occur, and

commanding the single brake pressure modulator to apply the vehicle brakes to decrease vehicle speed when it is determined that the vehicle is about to overturn.

12. The vehicle overturn prevention system of claim 11, wherein the control unit is programmed such that when the vehicle is not being braked, the vehicle is determined to be about to overturn when the wheel speed of the at least one inside wheel reaches zero or decreases at a greater rate than the at least one wheel on an outside side of the vehicle.

13. The vehicle overturn prevention system of claim 11, wherein the control unit is programmed such that when the vehicle is being braked, the vehicle is determined to be about to overturn when the wheel speed of the at least one inside wheel increases at a greater rate than the at least one wheel on an outside side of the vehicle.

16. The control unit of claim 13, wherein the control unit is programmed such that when the vehicle is being braked, the vehicle is determined to be about to overturn when the wheel speed of the at least one inside wheel increases at a greater rate than the at least one wheel on an outside side of the vehicle.

14. A control unit for a vehicle overturn assessment system for assessing whether a vehicle equipped with a plurality of wheel brakes is about to overturn, comprising:

a control unit,

wherein the control unit is arranged to communicate with a vehicle lateral acceleration sensor, a plurality of vehicle wheel speed sensors for sensing rotational wheel speed of at least one wheel on each lateral side of a vehicle and a single brake pressure modulator arranged to control actuation of the vehicle wheel brakes, and

wherein the control unit is programmed to monitor signals generated by the lateral acceleration sensor and the wheel speed sensors, monitor whether the single brake pressure modulator is applying braking pressure, command the single brake pressure modulator to apply braking pressure, and to assess whether a vehicle overturn event is about to occur by

determining whether a lateral acceleration sensed by the lateral acceleration sensor exceeds a predetermined threshold,

determining the rotational wheel speed of at least the at least one wheel on each lateral side of a vehicle,

conducting a rotational wheel speed change test when the lateral acceleration exceeds the predetermined threshold, wherein the test includes

if the vehicle is not being braked, applying a brake pressure to the vehicle brakes with the single brake pressure modulator, or

if the vehicle is being braked, lowering a brake pressure being applied by the single brake pressure modulator,

monitoring the wheel speed behaviour of at least the at least one wheel on an inside side of the vehicle, said inside side being the side facing away from the lateral acceleration direction, and

determining based on monitored wheel speed behaviour whether the vehicle overturn event is about to occur.

15. The control unit of claim 14, wherein the control unit is programmed such that when the vehicle is not being braked, the vehicle is determined to be about to overturn when the wheel speed of the at least one inside wheel one of reaches zero or decreases at a greater rate than the at least one wheel on an outside side of the vehicle.

17. A vehicle overturn assessment system for assessing whether a vehicle equipped with a plurality of wheel brakes is about to overturn, comprising:

a vehicle lateral acceleration sensor;

a plurality of vehicle wheel speed sensors for sensing rotational wheel speed of at least one wheel on each lateral side of a vehicle;

a single brake pressure modulator arranged to control actuation of all the vehicle brakes on at least one vehicle axle; and

a control unit,

wherein the control unit is programmed to monitor signals generated by the lateral acceleration sensor and the wheel speed sensors, monitor whether the single brake pressure modulator is applying braking pressure, and command the single brake pressure modulator to apply braking pressure, and

wherein the control unit is programmed to assess whether a vehicle overturn event is about to occur by

determining whether a lateral acceleration sensed by the lateral acceleration sensor exceeds a predetermined threshold,

determining the rotational wheel speed of at least the at least one wheel on each lateral side of a vehicle,

conducting a rotational wheel speed change test when the lateral acceleration exceeds the predetermined threshold, wherein the test includes

if the vehicle is not being braked, applying a brake pressure to the vehicle brakes with the single brake pressure modulator, or

if the vehicle is being braked, lowering a brake pressure being applied by the single brake pressure modulator,

monitoring the wheel speed behaviour of at least the at least one wheel on an inside side of the vehicle, said inside side being the side facing away from the lateral acceleration direction, and

determining based on monitored wheel speed behaviour whether the vehicle overturn event is about to occur.