Vehicle Stability Control Method

• US 20100211283A1
• Filed: 04/30/2010
• Published: 08/19/2010
• Est. Priority Date: 11/01/2007
• Status: Active Grant

• Current Assignee: Haldex Brake Products AB (SAF-HOLLAND SE)
• Original Assignee: Haldex Brake Products Corporation (Nippon Steel Corporation)
• Inventors: Crawley, James, Harrison, Dudley, Sayce-Jones, Robin
• Granted Patent: US 8,768,594 B2
• Time in Patent Office: Days
• US Class Current: 701/72
• CPC Class Codes: B60T 2230/03 Overturn, rollover
• CPC Class Codes: B60T 2240/06 Wheel load; Wheel lift
• 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

Abstract

A method of controlling travel of a vehicle equipped with an antilock braking system, including the steps of determining potential for one or more wheels to lift off the ground, deactivating the system in respect of the wheels with the lift off potential so the speed of these wheels is not taken into consideration when determining if anti-lock braking is required, applying a low-level test braking force to one or more of the wheels that has the lift off potential, monitoring the speed of the one or more wheels, and if the test braking force causes the wheel speed to fall below a predetermined percentage of the vehicle speed, triggering a stability alarm signal and/or applying a controlled braking force to reduce the vehicle speed.

Claims

1. A method of controlling travel of a vehicle equipped with an antilock braking system, the method comprising the steps of determining if there is potential for one or more wheels of the vehicle to lift off the ground, and if such a potential exists, deactivating the anti-lock braking system in respect of the wheels with the potential to lift off the ground so that the speed of these wheels is not taken into consideration when determining if anti-lock braking control is required, applying a low-level test braking force to the wheel or one of the wheels that has the potential to lift off the ground, monitoring the speed of the said wheel or wheels, and if the test braking force causes the speed of the or one or more of the monitored wheels to fall below a predetermined percentage of the vehicle speed, triggering a stability alarm signal and/or initiating a control intervention to reduce the vehicle speed.

2. The method according to claim 1 wherein the control intervention includes applying a controlled braking force to one or more of the wheels which do not have potential to lift off the ground so as to reduce the vehicle speed.

3. A method according to claim 1 wherein the method includes initiating a control intervention, the method further includes the steps of monitoring the potential for one or more of the vehicle wheels to lift off the ground, and ceasing the control intervention when the potential for one or more of the vehicle wheels to lift off the ground is no longer present.

4. A method according to claim 1 wherein the method may include the steps of applying further low level test braking pulses to the wheel or wheels which has the potential to lift off the ground, monitoring the speed of the or each of the said wheels, and ceasing the control intervention when the speed of the or each of the monitored wheels does not change significantly relatively to the speed of the vehicle following the application of the test braking pulse.

5. A method according to claim 1 wherein the method of determination of the potential for one or more of the vehicle wheels to lift off the ground includes measurement of the lateral acceleration of the vehicle.

6. A method according to claim 1 wherein, if it is determined that there is potential for one or more of the wheels to lift of the ground during braking following braking demand from a driver of the vehicle, or if the driver issues a demand for braking during a braking test pulse, where the braking demand requires a braking force which is below a predetermined level, the braking demand is met by increasing the braking force applied to the wheels without potential to lift off the ground by a greater amount than the braking force applied to the wheels with potential to lift off the ground.

7. A vehicle braking system comprising an electronic control unit of an electronic braking system including antilock braking control, the control unit being adapted to provide a braking signal to a plurality of brake actuators associated with wheels on first and second sides of the vehicle, wherein the control unit has the capability of determining if there is potential for one or more wheels of the vehicle to lift off the ground, and if such a potential exists, deactivating the anti-lock braking system in respect of the wheels with the potential to lift off the ground so that the speed of these wheels is not taken into consideration when determining if anti-lock braking control is required, generating a braking signal to apply a low-level test braking force to the wheel or one of the wheels that has the potential to lift off the ground, monitoring the speed of the said wheel or wheels, and if the test braking force causes the speed of the or one or more of the monitored wheels to fall below a predetermined percentage of the vehicle speed, triggering a stability alarm signal and/or initiating a control intervention to reduce the vehicle speed.