Method and device for determining a speed value

• US 6,611,781 B1
• Filed: 10/01/2001
• Issued: 08/26/2003
• Est. Priority Date: 08/06/1999
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Gutmann, Ralf
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): LAU, TUNG S
• Application Number:
  US09/807,035
• Time in Patent Office: 694 Days
• Field of Search: 702/148, 477/155, 701/36, 701/23, 303/113.1, 180/408, 364/426
• US Class Current: 702/148
• CPC Class Codes: B60T 2250/04 Vehicle reference speed; Vehicle body speed
• 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 8/174 characterised by using special control logic, e.g. fuzzy logic , neural computing
• CPC Class Codes: B60W 2050/0057 Frequency analysis, spectral techniques or transforms
• CPC Class Codes: G01P 3/50 for measuring linear speed G01P3/56 takes precedence
• CPC Class Codes: G01P 3/56 for comparing two speeds

Abstract

A method for determining a speed variable that represents the speed of a vehicle, including determining wheel speed variables, each of which describes the speed of a given wheel, determining weighting variables for the individual wheel speed variables, determining a support variable, via averaging, as a function of the wheel speed variables that have been weighted using the weighting variables, and determining the speed variable as a function of the support variable.

Claims

1. A method for determining a speed variable representing a speed of a vehicle having wheels, comprising:

determining wheel speed variables, each of the wheel speed variables describing a speed of a corresponding one of the wheels;

determining a respective weighting variable for each of the wheel speed variables;

determining a support variable as a function of weighted averaging of the wheel speed variables, each of the wheel speed variables being weighted by the respective weighting variable; and

determining the speed variable as a function of the support variable.

2. The method of claim 1, wherein:

each of the weighting variables is determined as a function of a predefined set of rules, the predefined set of rules being selectable from a plurality of predefined sets of rules as a function of a vehicle movement variable, the vehicle movement variable indicating at least a movement of the vehicle in a longitudinal direction; and

the vehicle movement variable is determined at talk least as a function of;

the wheel speed variables;

time derivatives of the wheel speed variables;

a function of a value corresponding to a longitudinal acceleration of the vehicle; and

a value indicating that a drive slip control system has performed at least one intervention procedure.

3. The method of claim 2, wherein the vehicle movement variable is useable for distinguishing among a plurality of vehicle movement types, the plurality of vehicle movement types including at least one of:

a decelerating vehicle movement, for which a first set of rules is selectable;

an accelerating vehicle movement, for which a second set of rules is selected; and

another vehicle movement that is neither decelerating nor accelerating, for which a third set of rules is selectable.

4. The method of claim 1, wherein the step of determining the respective weighting variable includes:

accounting for at least one modification phase that is present for wheels; and

determining time variables representing a duration of adjustment phases, the time variable being for determining the weighting variables.

5. The method of claim 1, further comprising:

determining a respective wheel variable for each of the wheels, each of the respective wheel variables representing a second time derivative of the speed of the corresponding one of the wheels;

wherein each respective weighting variable includes at least one of;

a stability variable determined at least as a function of the respective wheel variable and representing a measure of a wheel stability;

a situation variable including at least one of a status of the respective wheel speed variable relative to the speed variable and a value indicating a number of the wheels satisfying a predefined condition; and

a quality variable representing a measure of a quality of the respective weighting variable determined in a previous time increment.

6. The method of claim 1, wherein the speed variable includes a first component determined as a function of a value corresponding to a vehicle acceleration and a second component determined as a function of the support variable, the value corresponding to the vehicle acceleration including a longitudinal acceleration component determinable by a model and including an error component determined as a function of the support variable.

7. A method for determining a speed variable representing a speed of a vehicle having wheels, comprising:

determining wheel speed variables, each of the wheel speed variables describing a speed of a corresponding one of the wheels;

determining a respective weighting variable for each of the wheel speed variables;

determining a support variable as a function of weighted averaging of the wheel speed variables, each of the wheel speed variables being weighted by the respective weighting variable; and

determining the speed variable as a function of the support variable;

wherein;

each respective weighting variable is determined using at least one of a non-crisp logic system and a fuzzy logic system;

the at least one weighting variable represents at least one probability value; and

the at least one probability value indicates a suitability of the wheel for determining the at least one speed variable.

8. The method of claim 7, wherein:

the at least one of the non-crisp logic system and the fuzzy logic system is based on a plurality of membership functions, the plurality of membership functions forming at least one rule for performing at least one calculation for at least one input variable;

at least one of the plurality of membership functions has a fixed, predefined characteristic; and

at least one other of the plurality of membership functions has a variable characteristic; and

the plurality of membership functions are for at least one category, the at least one category including at least one of “

small”

, “

great”

, “

smaller than”

, “

greater than”

, “

close to”

, “

smallest”

, “

greatest”

, and “

closest to”

.

9. The method of claim 8, wherein each of the plurality of membership functions having a variable characteristic adapts to at least one of the at least one input variable and a reference variable, the reference variable being useable as a comparison value in the at least one calculation for the at least one input variable, the reference variable forming a basis for the at least one rule.

10. A method for determining a speed variable representing a speed of a vehicle having wheels, comprising:

determining wheel speed variables, each of the wheel speed variables describing a speed of a corresponding one of the wheels;

determining a respective weighting variable for each of the wheel speed variables;

determining a support variable as a function of weighted averaging of the wheel speed variables, each of the wheel speed variables being weighted by the respective weighting variable; and

determining the speed variable as a function of the support variable;

wherein each respective weighting variable is determined as a function of at least one of;

the wheel speed variables;

first wheel variables representing first time derivatives of the wheel speed variables;

second wheel variables representing second time derivatives of the wheel speed variables; and

at least one wheel braking force variable corresponding to a prevailing braking force between a tire and a road.

11. A method for determining a speed variable representing a speed of a vehicle having wheels, comprising:

determining wheel speed variables, each of the wheel speed variables describing a speed of a corresponding one of the wheels;

determining a respective weighting variable for each of the wheel speed variables;

determining a support variable as a fuinction of weighted averaging of the wheel speed variables, each of the wheel speed variables being weighted by the respective weighting variable;

determining the speed, variable as a function of the support variable;

determining, using each of the wheel speed variables, a respective slip-corrected wheel speed variable accounting for a slip present at the corresponding one of the wheels;

determining from the slip-corrected wheel speed variables transformed wheel speed variables, the transformed wheel speed variables accounting for a vehicle movement, the vehicle movement including the vehicle movement described by a yaw rate and a steering angle; and

determining from the transformed wheel speed variables extrapolated wheel speed variables, for which an acceleration of the vehicle is accounted for;

wherein these further steps are performed prior to the step of determining the respective weighting variable.

12. A method for determining a speed variable representing a speed of a vehicle having wheels, comprising:

determining wheel speed variables, each of the wheel speed variables describing a speed of a corresponding one of the wheels;

determining a respective weighting variable for each of the wheel speed variables;

determining a support variable as a function-of weighted averaging of the wheel speed variables, each of the wheel speed variables being weighted by the respective weighting variable;

determining the speed variable as a function of the support variable; and

at least one of suppressing and filtering small values among the weighting variables, before further processing the weighting variables.

13. A method for determining a speed variable representing a speed of a vehicle having wheels, comprising:

determining wheel speed variables, each of the wheel speed variables describing a speed of a corresponding one of the wheels;

determining a respective weighting variable for each of the wheel speed variables;

determining a support variable as a function of weighted averaging of the wheel speed variables, each of the wheel speed variables being weighted by the respective weighting variable;

determining the speed variable as a function of the support variable;

determining an evaluation variable as a function of the weighting variables, the evaluation variable being a measure of a suitability of the support variable for determining the speed variable;

determining a magnitude of a support to be performed as a function of the evaluation variable; and

calculating, as a function of the evaluation variable, a factor for determining a component of the speed variable associated with the support variable.

14. The method of claim 13, further comprising:

calculating, as a function of the evaluation variable, an uncertainty term value, wherein the uncertainty term value corresponds to a quality of the speed variable and determines the weighting variables.

15. A method for determining a speed variable representing a speed of a vehicle having wheels, comprising:

determining wheel speed variables, each of the wheel speed variables describing a speed of a corresponding one of the wheels;

determining a respective weighting variable for each of the wheel speed variables;

determining a support variable as a function of weighted averaging of the wheel speed variables, each of the wheel speed variables being weighted by the respective weighting variable; and

determining the speed variable as a function of the support variable;

wherein each of the-weighting variables is determined as a function of a predefined set of rules, the predefined set of rules being selectable from a plurality of predefined sets of rules as a function of a vehicle movement variable, the vehicle movement variable indicating at least a movement of the vehicle in a longitudinal direction;

wherein the vehicle movement variable is determined at least as a function of;

the wheel speed variables;

time derivatives of the wheel speed variables;

a function of a value corresponding to a longitudinal acceleration of the vehicle; and

a value indicating that a drive slip control system has performed at least one intervention procedure;

wherein the vehicle movement variable is useable for distinguishing among a plurality of vehicle movement types, the plurality of vehicle movement types including at least one of;

a decelerating vehicle movement, for which a first set of rules is selectable;

an accelerating vehicle movement, for which a second set of rules is selected; and

another vehicle movement that is neither decelerating nor accelerating, for which a third set of rules is selectable; and

wherein;

16. A method for determining a speed variable representing a speed of a vehicle having wheels, comprising:

determining wheel speed variables, each of the wheel speed variables describing a speed of a corresponding one of the wheels;

determining a respective weighting variable for each of the wheel speed variables;

determining a support variable as a function of weighted averaging of the wheel speed variables, each of the wheel speed variables being weighted by the respective weighting variable;

determining the speed variable as a function of the support variable; and

using at least one of a deceleration driving query set and an acceleration driving query set, wherein;

17. A device for determining a speed variable representing a speed of a vehicle having wheels, the device comprising:

means for determining wheel speed variables, each of the wheel speed variables describing a speed of a corresponding on of the wheels;

means for determining a respective weighting variable for each of the wheel speed variables;

means for determining a support variable as a function of weighted averaging of the wheel speed variables, each of the wheel speed variables being weighted using the respective weighting variable; and

means for determining the speed variable as a function of the support variable.

18. A device for determining a speed variable representing a speed of a vehicle having wheels, the device comprising:

a first arrangement for determining wheel speed variables, each of the wheel speed variables describing a speed of a corresponding one of the wheels;

a second arrangement for determining a respective weighting variable for each of the wheel speed variables;

a third arrangement for determining a support variable as a function of weighted averaging of the wheel speed variables, each of the wheel speed variables being weighted using the respective weighting variable; and

a fourth arrangement for determining the speed variable as a function of the support variable.