System for controlling brake pulsing at vehicle natural vibration frequencies

• US 20050179316A1
• Filed: 02/17/2004
• Published: 08/18/2005
• Est. Priority Date: 02/17/2004
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Tobler, Bill, Tiller, Michael, Bowles, Paul
• Granted Patent: US 7,380,890 B2
• Time in Patent Office: Days
• US Class Current: 303/113.100
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60T 2270/602 ABS features related thereto
• CPC Class Codes: B60T 8/173 Eliminating or reducing the effect of unwanted signals, e.g. due to vibrations or electrical noise
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A system is provided for controlling automatic brake systems to avoid pulsing vehicle brakes at certain natural vibration frequencies of the vehicle'"'"'s mechanical systems such as a powertrain and driveline. The natural vibration frequencies of the vehicle'"'"'s systems are determined and correlated with a range of possible braking regimes implemented by an on-board automatic brake control, such as an anti-lock braking (ABS) system. A proposed, normally appropriate ABS braking response to a sudden braking condition is either modified, accelerated or delayed when the proposed response is deemed likely to excite a vehicle natural frequency. The system improves ABS operation in vehicles having high effective inertia powertrains, such as those used in hybrid electric vehicles.

Claims

1. In a vehicle having an anti-lock braking system (ABS), a method of controlling the ABS, comprising:

determining one or more natural vibration frequencies of the vehicle;

selecting a nominal ABS response to a brake request;

altering the selected ABS response to avoid exciting the powertrain at the one or more determined frequencies.

2. The method of claim 1, comprising the step of determining which of the determined frequencies may be excited by the nominal ABS response.

3. The method of claim 2, wherein the step of determining which of the natural frequencies may be excited by the nominal ABS response comprises correlating a set of normally appropriate responses with the determined natural frequencies.

4. The method of claim 1, comprising the step of determining whether the selected nominal response will excite one of the determined natural frequencies.

5. The method of claim 1, wherein the altering step comprises delaying the nominal ABS response for a selected period of time.

6. The method of claim 1, wherein the altering step comprises accelerating the nominal ABS response.

7. The method of claim 1, wherein the nominal ABS response comprises pulsing the vehicle'"'"'s brakes and the altering step comprises altering the rate at which the brakes are pulsed.

8. A method of controlling an anti-lock braking system (ABS) to avoid exciting a natural vibration frequency of a vehicle, comprising:

developing a set of vehicle natural frequencies that may be excited by the ABS;

selecting an ABS response to a driving event requiring actuation of the ABS;

determining whether the selected ABS response may excite any of the frequencies in the developed set; and

,

altering the selected ABS response to avoid exciting any of the frequencies in the developed set.

9. The method of claim 8, wherein the developing step is performed by:

determining the natural frequencies of the vehicle; and

,

selecting the determined natural frequencies that are excited by the ABS.

10. The method of claim 9, wherein the natural frequencies are selected by correlating the results of plurality of ABS responses with the determined natural frequencies to thereby establish which of the natural frequencies are excited by the plurality of ABS responses.

11. The method of claim 8, further comprising the step of storing the set of frequencies in a memory, and wherein the determining step comprises comparing the selected ABS response with each of the frequencies stored in the memory.

12. The method of claim 8, wherein the altering step includes delaying the execution of the selected ABS response.

13. The method of claim 8, wherein the altering step comprises accelerating the execution of the selected ABS response.

14. The method of claim 8, wherein the altering step comprises altering the rate at which the ABS pulses the brakes of the vehicle.

15. A system for controlling an anti-lock braking system (ABS) to avoid exciting a natural vibration frequency of a vehicle, comprising:

computer memory for storing a set of vehicle natural frequencies that may be excited by the ABS, and for storing a set of possible ABS responses to driving conditions requiring actuation of the vehicle'"'"'s ABS; and

,

a set of programmed instructions for comparing a proposed ABS response with each of the natural frequencies stored in the memory.

16. The system of claim 15, wherein the programmed instructions include instructions for altering the proposed ABS response.

17. The system of claim 15, including a data input device for transferring the frequencies stored in the memory to the ABS.