Method and safety concept for recognizing defects in a drive system of a motor vehicle

• US 9,947,148 B2
• Filed: 11/27/2013
• Issued: 04/17/2018
• Est. Priority Date: 05/30/2011
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Moellmann, Joerg, Cosfeld, Ralf, Stolz, Heiko, Oesterreicher, Florian, John, Christoph, Huber, Karl-Josef, Smakman, Hendrikus, Schneider, Markus, Jakob, Heiko
• Primary Examiner(s): Shaawat, Mussa A
• Assistant Examiner(s): Kerrigan, Michael V
• Application Number:
  US14/092,388
• Publication Number:
  US 20140088817A1
• Time in Patent Office: 1,602 Days
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60T 17/22 Devices for monitoring or checking brake systems; Signal devices
• CPC Class Codes: B60T 2201/09 Engine drag compensation
• CPC Class Codes: B60T 2270/406 Test-mode; Self-diagnosis
• CPC Class Codes: B60T 2270/413 Plausibility monitoring, cross check, redundancy
• CPC Class Codes: B60T 8/885 using electrical circuitry
• CPC Class Codes: B60W 20/50 Control strategies for responding to system failures, e.g. for fault diagnosis, failsafe operation or limp mode
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2520/26 Wheel slip
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 50/0205 Diagnosing or detecting failures; Failure detection models
• CPC Class Codes: B60W 50/029 Adapting to failures or work around with other constraints, e.g. circumvention by avoiding use of failed parts
• CPC Class Codes: G07C 5/0808 Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A method and associated safety system are provided for the recognition of defects in a drive system of a motor vehicle, having an electronically controllable brake control system and having at least one electronically controlled driving engine, an electronically controllable clutch and/or having an electronically controllable transmission. An electronic braking control device is assigned to the brake control system, which braking control device is connected with an independent monitoring module. The independent monitoring module checks for an occurrence of an implausible braking torque, for detecting a defect in the drive system.

Claims

1. A method for recognizing a defect in a drive system of a motor vehicle equipped with an electronically controllable brake control system, the drive system having an electronically controllable driving engine, an electronically controllable clutch and/or an electronically controllable transmission, wherein the method comprises the acts of:

assigning an electronic braking control device to the brake control system, the braking control device being connected with an independent monitoring module;

determining, via the independent monitoring module, an occurrence of an implausible braking torque;

determining, via the independent monitoring module, that the implausible braking torque was caused by a defect in at least one of the electronically controllable driving engine, the electronically controllable clutch and the electronically controllable transmission, and not by the electronically controllable brake control system;

upon receiving a defined defect signal from the independent monitoring module, interrupting, via an electronic control device of the drive system, (i) a power connection between the driving engine and driven wheels of the motor vehicle, or (ii) a power transmission of the driving engine.

2. The method according to claim 1, further comprising the act of:

upon recognizing the defect, outputting, via the independent monitoring module, the defined defect signal to the electronic control device of the drive system.

3. The method according to claim 2, wherein for determining the occurrence of the implausible braking torque, the independent monitoring module evaluated rotational wheel speeds of driven wheels of the motor vehicle for a wheel slip recognition, and determines the occurrence of the implausible braking torque when wheel slip exceeds a predefined threshold value.

4. The method according to claim 2, wherein for determining the occurrence of the implausible braking torque, the independent monitoring module evaluates vehicle deceleration by way of a longitudinal acceleration sensor and/or by way of rotational wheel speeds of driven wheels, the determination of the occurrence of the implausible braking torque being determined when the vehicle deceleration exceeds a predefined threshold value.

5. The method according to claim 1, wherein for determining the occurrence of the implausible braking torque, the independent monitoring module evaluates rotational wheel speeds of driven wheels of the motor vehicle for a wheel slip recognition, and determines the occurrence of the implausible braking torque when wheel slip exceeds a predefined threshold value.

6. The method according to claim 5, further comprising the act of:

suppressing the recognition of the defect even when the implausible braking torque is determined if a defined exclusion criterion is present.

7. The method according to claim 1, wherein for determining the occurrence of the implausible braking torque, the independent monitoring module evaluates vehicle deceleration by way of a longitudinal acceleration sensor and/or by way of rotational wheel speeds of driven wheels, the determination of the occurrence of the implausible braking torque being determined when the vehicle deceleration exceeds a predefined threshold value.

8. The method according to claim 7, further comprising the act of:

suppressing the recognition of the defect even when the implausible braking torque is determined if a defined exclusion criterion is present.

9. The method according to claim 1, further comprising the act of:

suppressing the recognition of the defect even when the implausible braking torque is determined if a defined exclusion criterion is present.

10. The method according to claim 9, wherein the defined exclusion criterion is one of:

a recognized activated hand brake, a recognized skidding situation, a recognized towing situation, an only brief recognition of the implausible braking torque, or an early ABS control.

16. The method according to claim 1, further comprising the act of:

suppressing the recognition of the defect, even when the implausible braking torque is determined, in response to a recognized skidding situation.

17. The method according to claim 1, wherein determining that the implausible breaking torque was caused by the defect includes determining whether a wheel slip exceeds a predefined threshold despite a demand for engine torque meeting a predefined threshold.

11. A safety system for a motor vehicle, comprising:

an electronically controllable brake control system;

one or more of;

an electronically controllable driving engine, an electronically controllable clutch, or an electronically controllable transmission;

an electronically controllable braking control device assigned to the brake control system;

an independent monitoring module connected with the braking control device, wherein the independent monitoring module comprises a microprocessor and a computer readable medium having stored thereon program code segments that;

assign an electronic braking control device to the brake control system, the braking control device being connected with an independent monitoring module; and

determine, via the independent monitoring module, an occurrence of an implausible braking torque; and

determine, via the independent monitoring module, that the implausible braking torque was caused by a defect in at least one of the electronically controllable driving engine, the electronically controllable clutch and the electronically controllable transmission, and not by the electronically controllable brake control system; and

at least one controlling device configured to control the drive system and being configured to interrupt a power connection or a power transmission between the driving engine and driven wheels of the motor vehicle on receiving a defined defect signal from the independent monitoring module.

12. The safety system according to claim 11,

wherein

the independent monitoring module is connected with the controlling device to output the defined defect signal upon the occurrence of the implausible braking torque, in which event the controlling device interrupts the power connection or the power transmission.

13. The safety system according to claim 12, wherein the microprocessor and computer readable medium having stored thereon program code segments are further configured to suppress the recognition of the defect, even when the implausible braking torque is determined, in response to a recognized skidding situation.

14. The safety system according to claim 12, wherein the microprocessor and computer readable medium having stored thereon program code segments are further configured to suppress the recognition of the defect, even when the implausible braking torque is determined, if a defined exclusion criterion is present.

15. The safety system according to claim 14, wherein the defined exclusion criterion is one of:

a recognized activated hand brake, a recognized skidding situation, a recognized towing situation, an only brief recognition of the implausible braking torque, or an early ABS control.