System and method for detecting roll rate sensor fault

• US 20040181329A1
• Filed: 12/22/2003
• Published: 09/16/2004
• Est. Priority Date: 08/01/2002
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Xu, Li, Tseng, Hongtei Eric
• Granted Patent: US 7,110,870 B2
• Time in Patent Office: Days
• US Class Current: 701/38
• CPC Class Codes: B60G 17/0162 mainly during a motion involving steering operation, e.g. cornering, overtaking B60G17/0164 takes precedence
• CPC Class Codes: B60G 17/0182 involving parameter estimation, e.g. observer, Kalman filter
• CPC Class Codes: B60G 17/0185 for failure detection
• CPC Class Codes: B60G 17/0195 characterised by the regulation being combined with other vehicle control systems conjoint control of vehicle sub-units including control of suspension systems B60W10/22
• CPC Class Codes: B60G 2600/08 Failure or malfunction detecting means
• CPC Class Codes: B60G 2600/1871 Optimal control; Kalman Filters
• CPC Class Codes: B60G 2800/0194 transversal with regard to vehicle
• CPC Class Codes: B60G 2800/215 by applying a braking action on each wheel individually
• CPC Class Codes: B60G 2800/80 Detection or control after a system or component failure
• CPC Class Codes: B60G 2800/922 EBV - Electronic brake force distribution
• CPC Class Codes: B60R 16/0233 Vehicle tilting, overturning or roll over
• CPC Class Codes: B60R 2021/0018 Roll-over
• CPC Class Codes: B60R 2021/01122 Prevention of malfunction
• CPC Class Codes: B60R 2021/01327 Angular velocity or angular acceleration
• CPC Class Codes: B60R 21/01 Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents electrical circuits for transmission of signals between steering wheel and the vehicle itself B60R16/027; for electrically actuating belt retractor locking means B60R22/343
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• CPC Class Codes: B60T 17/22 Devices for monitoring or checking brake systems; Signal devices
• CPC Class Codes: B60T 2230/03 Overturn, rollover
• CPC Class Codes: B60T 2240/06 Wheel load; Wheel lift
• CPC Class Codes: B60T 2270/413 : Plausibility monitoring, cross check, redundancy
• CPC Class Codes: B60T 8/00 : Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force by changing number of effective brake cylinders in power brake systems B60T17/10
• 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 8/1755 : Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60T 8/241 : Lateral vehicle inclination
• CPC Class Codes: B60T 8/243 : for roll-over protection
• CPC Class Codes: B60T 8/885 : using electrical circuitry
• CPC Class Codes: B60W 30/04 : related to roll-over prevention

Abstract

A control system for an automotive vehicle having a vehicle body includes a sensor cluster having a housing oriented within the vehicle body. A roll rate sensor is positioned within the housing and generates a roll rate sensor signal corresponding to a roll angular motion of the sensor housing. A controller receives the roll rate sensor signal, the controller generates a residue signal in response to a sensor error or a measurement error. The controller sets a fault condition in response to the residue signal larger than a dynamic threshold and a magnitude of the roll rate signal above a fault condition threshold. The controller sets a fault flag in response to the fault condition indicated for a predetermined time during which no double wheel lift occurs.

Claims

1. A method for detecting a roll stability control system sensor fault comprising:

generating a compensated roll rate signal having a first threshold;

generating a lateral acceleration signal having a second threshold;

generating a reference velocity signal having a third threshold;

generating a yaw rate signal having a fourth threshold; and

generating a small roll rate shift flag in response to at least one of said first threshold, said second threshold, said third threshold, and said fourth threshold exceeded for greater than a predetermined time.

2. A method as in claim 1 wherein generating said small roll rate shift flag further comprises generating said small roll rate shift flag in response to said second threshold, said third threshold or said fourth threshold exceeded for turning situations or straight driving situations;

said second threshold, said third threshold or said fourth threshold having alternate threshold limits for each of said turning situations and said driving situations.

3. A method as in claim 2 wherein generating said small roll rate shift flag further comprises generating said small roll rate shift flag as a function of a small roll rate fault including 3-7 deg/s roll rate fault.

4. A method as in claim 2 wherein generating said small roll rate shift flag further comprises generating said small roll rate shift flag for three situations including straight driving, 0.1 g steady state turns, and 0.2 g steady state turns during which the roll rate ω

_x term should be zero.

5. The method of claim 1 further comprising disabling the method when RSC, AYC or TCS are in cycle.

6. The method of claim 1 further comprising shutting down roll stability control in response to said small roll rate shift flag.

7. The method of claim 1 further comprising activating a warning lamp in response in response to said small roll rate shift flag.

8. The method of claim 1 further comprising terminating roll stability control in response to said small roll rate shift flag and in response to a detection that there is no double wheel lift.

9. The method of claim 1 further comprising generating a dynamic factor;

and

generating a determination of stability as a function of said dynamic factor.

10. The method of claim 9 further comprising low-pass filtering said dynamic factor.

11. The method of claim 1 further comprising generating a dynamic factor;

generating a dynamic threshold; and

generating a determination of vehicle stability or vehicle position on a banked surface as a function of said dynamic factor and said dynamic threshold.

12. The method of claim 1, further comprising tuning said first threshold, said second threshold, said third threshold, and said fourth threshold for achieving detection of errors at a desired rate and to avoid false error detection.

13. The method of claim 1 further comprising compensating for a valid signal bias in said roll rate signal.

14. The method of claim 1 further comprising generating a residue signal as a function of a reference angle signal and said roll rate signal;

adjusting said residue signal as a function of a sine of bank angle signal;

generating an adjusted residue signal;

generating a fault condition threshold from said adjusted residue signal as a function of at least one of said first threshold, said second threshold, said third threshold, or said fourth threshold;

setting a fault condition in response to said adjusted residue signal larger than a dynamic threshold and a magnitude of said roll rate signal above said fault condition threshold; and

setting a fault flag in response to said fault condition indicated for a predetermined time during which no double wheel lift occurs.

17. The method of claim 1-5 further comprising applying a deadband to said yaw rate signal.

18. The method of claim 17 wherein applying a deadband to said yaw rate signal further comprises filtering said yaw rate signal.

15. A method for detecting a roll stability control system sensor fault comprising:

generating a roll rate fault signal as a function of a reference angle signal, a roll rate signal, and a yaw rate signal;

generating global variables as a function of said reference angle signal;

adding a virtual high frequency component of pitch estimation to one of said global variables;

generating a vehicle dynamic fault threshold as a function of said global variables;

generating a residue signal as a function of said reference angle signal and said roll rate signal;

adjusting said residue signal as a function of a sine of bank angle signal;

generating an adjusted residue signal;

generating a fault condition threshold from said adjusted residue signal as a function of said vehicle dynamic fault threshold;

setting a fault condition in response to said adjusted residue signal larger than a dynamic threshold and a magnitude of said roll rate signal above said fault condition threshold; and

setting a fault flag in response to said fault condition indicated for a predetermined time during which no double wheel lift occurs.

16. The method of claim 15 further comprising applying a deadband to said vehicle dynamic threshold.

19. The method of claim 15, wherein generating said vehicle dynamic threshold further comprises generating at least one of a yaw threshold, a pitch threshold, or a roll threshold.

20. The method of claim 15 further comprising passing said roll rate fault signal through a direction dependent low pass filter;

generating a filtered roll rate fault signal; and

generating a dynamic memory from said filtered roll rate fault signal.

21. The method of claim 20 further comprising saturating said filtered roll rate fault signal.

22. The method of claim 15, wherein generating said roll rate fault signal further comprises generating said roll rate fault signal as a function of at least one of a roll angle signal, a pitch angle signal or a yaw angle signal.

24. A system as recited in claim 21, wherein said controller compensates said roll rate sensor signal for all valid signal faults.

25. A system as recited in claim 21, wherein said controller is further adapted to shut down a roll over detection system in response to said fault flag.

26. A system as recited in claim 21, wherein said controller generates a small roll rate shift flag in response to at least one vehicle dynamic threshold exceeded for greater than a predetermined time.

27. A system as recited in claim 26, wherein said vehicle dynamic threshold of:

said roll rate sensor signal, a lateral acceleration signal, a reference velocity signal, or a yaw rate signal.

23. A control system for an automotive vehicle having a vehicle body comprising:

a sensor cluster having a housing oriented within the vehicle body;

a roll rate sensor positioned within the housing generating a roll rate sensor signal corresponding to a roll angular motion of said housing; and

a controller receiving said roll rate sensor signal, said controller generating a residue signal in response to a sensor error or a measurement error, said controller setting a fault condition in response to said residue signal larger than a dynamic threshold and a magnitude of said roll rate signal above a fault condition threshold, and said controller setting a fault flag in response to said fault condition indicated for a predetermined time during which no double wheel lift occurs.

28. A method for detecting a roll rate sensor fault comprising:

generating a reference velocity signal;

generating a lateral acceleration signal;

generating a compensated rollrate signal;

generating a yaw rate signal;

generating a dynamic factor; and

generating a small fault flag as a function of, in excess of a predetermined time, at least one of said reference velocity signal exceeding a reference velocity threshold, said lateral acceleration signal exceeding a lateral acceleration threshold, said compensated rollrate signal exceeding a compensated rollrate threshold, said yaw rate signal exceeding a yaw rate threshold, or said dynamic factor exceeding a dynamic threshold.

29. A method for detecting a roll rate sensor fault comprising:

generating a residue signal;

generating a global roll plausibility signal;

generating a dynamic factor signal;

generating a compensated rollrate signal;

generating a pitch signal;

generating a small fault flag;

generating a sticking signal fault flag; and

generating a dynamic factor threshold, a plausibility of fault signal, and a plausibility fault flag as a function of said residue signal, said global plausibility signal, said dynamic factor signal, said compensated rollrate signal, said pitch signal, said small fault flag, and said sticking fault flag.

30. The method of claim 29 further comprising setting a fault condition in response to said residue signal larger than said dynamic threshold.

31. The method of claim 30, wherein setting further comprises setting said fault condition in response to said rollrate signal exceeding a rollrate threshold.

32. The method of claim 30 further comprising setting a fault flag in response to said fault condition set for a predetermined time wherein at least three vehicle tires contact a road surface.