Triggering method for activating a lateral velocity estimating system for occupant protection devices

• US 9,085,286 B2
• Filed: 12/21/2005
• Issued: 07/21/2015
• Est. Priority Date: 02/03/2005
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Lich, Thomas, Schmid, Michael
• Primary Examiner(s): Cheung, Mary
• Application Number:
  US11/795,750
• Publication Number:
  US 20100042294A1
• Time in Patent Office: 3,499 Days
• Field of Search: 701/41, 701/65, 701 70- 74, 701/80, 701/82, 280/1.202, 280/5.51, 180/204, 180/6.2, 180/6.24, 180/9.38
• US Class Current: 1/1
• CPC Class Codes: B60R 2021/01304 monitoring rough road condition
• CPC Class Codes: B60R 2021/01313 monitoring the vehicle steering system or the dynamic control system
• CPC Class Codes: B60R 2021/01327 Angular velocity or angular acceleration
• 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 2230/02 Side slip angle, attitude angle, floating angle, drift angle
• 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: B60W 2520/12 Lateral speed
• CPC Class Codes: B60W 30/04 related to roll-over prevention

Abstract

In a triggering method for activating a lateral velocity estimating system for occupant protection devices, one or more vehicle-dynamics variables are sensed and evaluated. Based on the sensed vehicle-dynamics variables an oversteer and understeer detection procedure and a road condition detection procedure are performed, which are evaluated for activation of the lateral velocity estimating system.

Claims

1. A triggering method for activating a lateral velocity estimating system for a vehicle-occupant protection device of a vehicle, comprising:

detecting a plurality of vehicle-dynamics variables;

performing, based on the detected vehicle-dynamics variables, a) a first detection procedure for detecting one of an oversteer and understeer of a vehicle, and b) a second detection procedure for detecting, as a road condition for a road on which the vehicle is traveling, a frictional coefficient of the road'"'"'s surface; and

activating the lateral velocity estimating system depending on results of the first and second detection procedures.

2. The method as recited in claim 1, wherein during the first detection procedure, an Ackermann yaw rate is calculated based on a present steering angle, a present longitudinal velocity, and a predetermined vehicle wheelbase.

3. The method as recited in claim 2, wherein during the first detection procedure, a float angle change is calculated from a presently measured lateral acceleration, a present longitudinal velocity, and a presently measured yaw rate.

4. The method as recited in claim 3, wherein the presently measured yaw rate is measured with the aid of at least one of:

a) a yaw rate sensor;

b) a pair of linear acceleration sensors; and

c) a sensor disposed at the center of gravity that measures a linear acceleration in at least two spatial axes.

5. The method as recited in claim 1, wherein the second detection procedure includes calculating a theoretical lateral acceleration as a function of a presently measured yaw rate and a longitudinal velocity of the vehicle.

6. The method as recited in claim 5, wherein the frictional coefficient is detected by comparing the theoretical lateral acceleration to a presently measured lateral acceleration.

7. The method as recited in claim 1, wherein the lateral velocity estimating system is activated in response to determining that the results of the first and the second detection procedures indicate a skidding situation involving one of a low and a moderate frictional coefficient.

8. A triggering method for activating a lateral velocity estimating system for a vehicle-occupant protection device of a vehicle, comprising:

detecting a plurality of vehicle-dynamics variables;

performing, based on the detected vehicle-dynamics variables, a) a first detection procedure for detecting one of an oversteer and understeer of a vehicle, and b) a second detection procedure for detecting a road condition for a road on which the vehicle is traveling; and

activating the lateral velocity estimating system depending on results of the first and second detection procedures;

wherein;

during the first detection procedure;

an Ackermann yaw rate is calculated based on a present steering angle, a present longitudinal velocity, and a predetermined vehicle wheelbase; and

a float angle change is calculated from a presently measured lateral acceleration, a present longitudinal velocity, and a presently measured yaw rate; and

the float angle change is ascertained based on a starting float angle which is continuously determined with the aid of a long-term integration.

9. A triggering method for activating a lateral velocity estimating system for a vehicle-occupant protection device of a vehicle, comprising:

detecting a plurality of vehicle-dynamics variables;

performing, based on the detected vehicle-dynamics variables, a) a first detection procedure for detecting one of an oversteer and understeer of a vehicle, and b) a second detection procedure for detecting a road condition for a road on which the vehicle is traveling, wherein during the first detection procedure;

an Ackermann yaw rate is calculated based on a present steering angle, a present longitudinal velocity, and a predetermined vehicle wheelbase; and

a float angle change is calculated from a presently measured lateral acceleration, a present longitudinal velocity, and a presently measured yaw rate;

activating the lateral velocity estimating system depending on results of the first and second detection procedures; and

generating a first flag signal for one of the oversteer and understeer, wherein the generation of the first flag signal includes;

combining, during the first detection procedure, the Ackermann yaw rate, the float angle change, and the presently measured yaw rate with one another;

evaluating the combined Ackermann yaw rate, the float angle change, and the presently measured yaw rate by a first logic circuit; and

setting the first flag signal by the first logic circuit if one of a vehicle oversteer and understeer is ascertained during the evaluation.

10. The method as recited in claim 9, wherein during the second detection procedure, a theoretical lateral acceleration is calculated from the presently measured yaw rate and the present longitudinal velocity.

11. The method as recited in claim 10, further comprising:

generating a low-μ

flag signal during the second detection procedure, wherein μ

represents a frictional coefficient, and wherein the generating of the low-μ

flag signal includes;

combining the theoretical lateral acceleration, the presently measured lateral acceleration, and the first flag signal; and

evaluating the combined theoretical lateral acceleration, presently measured lateral acceleration, and first flag signal by a second logic circuit.

12. The method as recited in claim 11, further comprising:

setting, by the second logic circuit, the low-μ

flag signal when one of a low and moderate value of μ

for the road on which the vehicle is traveling is ascertained in the evaluation.

13. The method as recited in claim 11, further comprising:

combining the low-μ

flag signal, the first flag signal, the presently measured yaw rate, the presently measured lateral acceleration, and the calculated float angle change;

evaluating the combined low-μ

flag signal, first flag signal, presently measured yaw rate, presently measured lateral acceleration, and calculated float angle change, by a third logic circuit; and

activating the lateral velocity estimating system if a skidding situation involving one of a low and a moderate frictional coefficient is ascertained in the evaluation.

14. A triggering method for activating a lateral velocity estimating system for a vehicle-occupant protection device of a vehicle, comprising:

detecting a plurality of vehicle-dynamics variables;

performing, based on the detected vehicle-dynamics variables, a) a first detection procedure for detecting one of an oversteer and understeer of a vehicle, and b) a second detection procedure for detecting a road condition for a road on which the vehicle is traveling, wherein a float angle change is ascertained during the first detection procedure from a starting float angle that is continuously determined through integration; and

activating the lateral velocity estimating system depending on results of the first and second detection procedures.

15. The method as recited in claim 14, wherein the float angle change is calculated from a presently measured lateral acceleration, a present longitudinal velocity, and a presently measured yaw rate.