Method for regulating directional stability

• US 20040073351A1
• Filed: 07/28/2003
• Published: 04/15/2004
• Est. Priority Date: 01/26/2001
• Status: Abandoned Application

• Current Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Original Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Inventors: Haberhauer, Markus
• Application Number:
  US10/467,390
• Publication Number:
  US 20040073351A1
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60T 2250/03 Vehicle yaw rate
• CPC Class Codes: B60T 2270/413 Plausibility monitoring, cross check, redundancy
• 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 8/885 using electrical circuitry

Abstract

In a method of controlling the driving stability of a vehicle, signal errors emitted by yaw rate sensors are detected/determined by way of monitoring strategies. In order to increase the reliability of driving stability control operations, it is determined during stationary driving behavior with a steering movement whether the value of the yaw rate signal {dot over (ψ)}_Sensor deviates in percentage or nominally from a redundant value {dot over (ψ)}_mean produced from other measured or calculated variables related to the vehicle. In this case, the control of driving stability is influenced under the condition that a comparison value calculated from the value of the yaw rate signal and the redundant value exceeds a predetermined threshold value.

Claims

1. Method of controlling the driving stability of a vehicle, wherein signal errors emitted by yaw sensors are determined by way of monitoring strategies, characterized in that during stationary driving behavior with a steering movement it is determined whether the value of the yaw rate signal ({dot over (ψ

)}_Sensor) deviates in percentage or nominally from a redundant value ({dot over (ψ

)}_mean ) produced from other measured or calculated variables of the vehicle, and that in this case the control (72, 80) of driving stability is influenced under the condition that a comparison value (Δ

{dot over (ψ

)}(%)) produced from the value of the yaw rate sianal ({dot over (ψ

)}_Sensor) and the redundant value ({dot over (ψ

)}_mean) exceeds at least one predetermined threshold value (>

80%, >

60%).

2. Method as claimed in claim 1, characterized in that the value of the yaw rate signal is compared with the redundant value when a counter (22) reaches a predetermined value.

3. Method as claimed in claim 1 or 2, characterized in that the counter (22) is increased in dependence on a time lapsed (≧

7) during which the stationary driving behavior with a steering movement is determined.

4. Method as claimed in any one of claims 1 to 3, characterized in that stationary driving behavior (20) is determined when at least one of the following conditions is satisfied:

a) |{dot over (ψ

)}_mL−

{dot over (ψ

)}_mq|<

a first threshold value K1, preferably 12°

/s, especially 7°

/s

a) |{dot over (ψ

)}_mL−

{dot over (ψ

)}_mν

|<

a second threshold value K2, preferably 12°

/s, especially 7°

/s

b) |δ

LP|<

a third threshold value K3, preferably 200°

/s, especially 100°

/s

c) |α

_q|<

a fourth threshold value K4, preferably 0.7 g, especially 0.5 g

d) anti-lock control (ABS), electronic brake force distribution (EBD), brake intervention-traction slip control is not active, and/or

e) the wheels of the vehicle do not show non-stationary wheel behavior (slip criteria)

f) the vehicle does not show oversteering driving behavior

g) the vehicle does not show understeering driving behavior.

5. Method as claimed in any one of claims 1 to 4, characterized in that a steering movement is determined when at least the conditions are satisfied:

|steering angle|at the wheel>

threshold value L1, preferably 1°

, and

|lateral acceleration|>

threshold value Q1, preferably 0.081 g.

6. Method as claimed in any one of claims 1 to 5, characterized in that the redundant value is produced from at least two model-based variables in which at least one of the following variables is included:

wheel speeds of the wheels, track width, steering wheel angle, wheel base, vehicle speed, vehicle reference speed, the characteristic vehicle speed, or the steering velocity.

7. Method as claimed in claim 6, characterized in that the redundant value is produced by averaging (32) according to the relation

8. Method as claimed in any one of claims 1 to 7, characterized in that the comparison value is determined (34) as a percentage difference value Δ

{dot over (ψ

)}(%)=({dot over (ψ

)}_Sensor/{dot over (ψ

)}_mean) from the deviation of the value of the yaw rate signal {dot over (ψ

)}_Sensor from the redundant value {dot over (ψ

)}_mean.

9. Method as claimed in any one of claims 1 to 8, characterized in that a flag (bit) (SMAL_POS_GAIN_FAILURE_SUSPICION) is set (52) when the percentage difference value exceeds a threshold value K5 (DELTA_YA>

60%).

10. Method as claimed in any one of claims 1 to 9, characterized in that a flag (bit) (POS_GAIN_FAILURE_SUSPICION or NEG_GAIN_FAILURE_SUSPICION) is set when the percentage difference value exceeds a threshold value K6 (DELTA_YR>

80%) or threshold value K7 (DELTA_YR<

−

50%).

11. Method as claimed in any one of claims 1 to 10, characterized in that the value of a counter (60) for a positive scaling error suspicion or the value of a counter (60.1) for a negative scaling error suspicion is increased when a positive or negative scaling error (>

80%) is determined.

12. Method as claimed in any one of claims 1 to 11, characterized in that an ESP entry and/or exit threshold is increased by a model-based redundant value {dot over (ψ

)}_mL that is weighted with a factor of the percentage difference value Δ

{dot over (ψ

)}(%) when the value of the counter (60, 60.1) exceeds a threshold value K8 (70).

13. Method as claimed in claim 12, characterized in that the model-based redundant value is calculated according to the following relation

14. Method as claimed in any one of claims 1 to 13, characterized in that the control of driving stability is terminated when the counter (78) has reached or exceeded a ninth threshold value K9 and the number of exceeding events satisfies a predefined provision.

15. Method as claimed in any one of claims 1 to 14, characterized in that an error is registered in an error memory when driving stability control is terminated.

16. Method as claimed in any one of claims 1 to 15, characterized in that the counters are reset when an ESP oversteering condition is found out.

17. Method as claimed in any one of claims 1 to 16, characterized in that the counters are reset when no scaling threshold exceeding events (50, 54.1) in a stationary curve are detected in a predetermined period.