DEVICE FOR EVALUATING THE TRANSVERSE ACCELERATION OF AN AUTOMOBILE VEHICLE AND CORRESPONDING METHOD

• US 20110178685A1
• Filed: 06/26/2009
• Published: 07/21/2011
• Est. Priority Date: 07/09/2008
• Status: Active Grant

• Current Assignee: Renault Sas (Renault)
• Original Assignee: Renault Sas (Renault)
• Inventors: Vandekerhove, Remi
• Granted Patent: US 8,930,097 B2
• Time in Patent Office: Days
• US Class Current: 701/51
• 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 2510/1005 Transmission ratio engaged
• CPC Class Codes: B60W 2520/26 Wheel slip
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 30/18145 Cornering
• CPC Class Codes: B60W 40/109 Lateral acceleration

Abstract

A device for evaluating the transverse acceleration of a motor vehicle measures the rotational speeds of two wheels of the vehicle, estimates the transverse acceleration of the vehicle from these speeds, and calculates, as a function of vehicle operating parameters, particularly of the rotational speeds of the wheels and of the transmission ratio engaged, a Boolean slip variable which is negative if the transverse estimated acceleration is relevant for detecting a bend, and which is positive if the reverse is true.

Claims

1-10. -10. (canceled)

11. A device for evaluating transverse acceleration of an automobile vehicle, comprising:

means for measuring rotational speeds of two wheels of the vehicle;

a module that estimates the transverse acceleration of the vehicle from the measured speeds; and

a validation module that calculates, as a function of operating parameters of the vehicle, of rotational speeds of the wheels, and of transmission ratio engaged, a Boolean skidding variable which is negative if the transverse acceleration estimated by the module is relevant for detecting a turn, and which is positive if the reverse is true.

12. The evaluation device as claimed in claim 11, in which the wheels are a right drive wheel and a left drive wheel belonging to one and a same wheel set of the vehicle.

13. The evaluation device as claimed in claim 11, further comprising:

a correction module that delivers a corrected value of the transverse acceleration such that the corrected value is equal to a previous estimated value of the transverse acceleration if the Boolean skidding variable is negative, and the corrected value is equal to an arbitrary constant if the reverse is true.

14. The evaluation device as claimed in claim 11, in which the validation module comprises a first Boolean module that delivers a first Boolean wheel over-acceleration variable, which module comprises first means for calculating the accelerations of the two wheels, second means for calculating a plausible acceleration threshold for the wheels as a function of the transmission ratio engaged, first means for comparison of the accelerations of each of the two wheels with respect to the plausible wheel acceleration threshold, second means for comparison of the difference in speed between the two wheels with respect to a difference threshold, and means for storing the Boolean wheel over-acceleration variable.

15. The evaluation device as claimed in claim 14, in which the validation module further comprises a second Boolean module receiving the value of the acceleration setpoint from the driver and that delivers a second in-turn Boolean pedal application variable, and in which the validation module comprises a summing means that adds together the Boolean wheel over-acceleration variable and the in-turn Boolean pedal application variable to obtain the Boolean skidding variable.

16. The evaluation device as claimed in claim 15, in which the second Boolean module comprises means for determining the derivative of the acceleration setpoint from the driver with respect to time, comprises means for comparison of the acceleration setpoint, of its derivative and of a previously estimated transverse acceleration, with respect to three values of setpoint threshold, of setpoint derivative threshold, of accelerated centrifugation threshold, respectively, and comprises means for storing the in-turn Boolean pedal application variable.

17. A device for detecting a turning situation for controlling an automobile vehicle mechanism, or for automatic transmission control, comprising:

an evaluation device as claimed in claim 11; and

an arbitration module that decides whether the vehicle is in a turning situation, the arbitration module comprising means for comparison of the transverse acceleration of the vehicle and of the derivative with respect to time of the transverse acceleration, with a first value of arbitration threshold and a second value of arbitration threshold, respectively.

18. A method for evaluating the transverse acceleration of an automobile vehicle, comprising:

measuring rotational speeds of two drive wheels of the vehicle;

estimating transverse acceleration of the vehicle from the measured wheel speeds; and

calculating a Boolean skidding variable as a function of operating parameters of the vehicle, of rotational speeds of the drive wheels, and of transmission ratio engaged, which variable is negative if the transverse acceleration estimated by the module is relevant for detecting a turn, and which is positive if the reverse is true.

19. The evaluation method as claimed in claim 18, in which, if the skidding variable is positive, the corresponding transverse acceleration is then corrected by assigning it an arbitrary value.

20. The evaluation method as claimed in claim 18, in which the Boolean skidding variable is the sum of a first Boolean wheel over-acceleration variable and of a second Boolean in-turn pedal application variable whose calculation comprises:

using a stored data map, a plausible wheel acceleration threshold is calculated as a function of the transmission ratio engaged;

if the derivative with respect to time of one of the measured wheel rotational speeds is greater than the plausible wheel acceleration threshold, the wheel over-acceleration variable is positive;

if the two derivatives with respect to time of the measured wheel rotational speeds are less than this plausible wheel acceleration threshold and if, simultaneously, the difference in rotational speeds of the two wheels is less than a difference threshold, the wheel over-acceleration variable is negative;

in other cases, the wheel over-acceleration variable keeps its value;

the derivative with respect to time of the acceleration setpoint from the driver is calculated;

the acceleration setpoint from the driver, its derivative, and the estimated transverse acceleration of the vehicle are compared with respect to three values of setpoint threshold, of setpoint derivative threshold and of accelerated centrifugation threshold;

if the three values are simultaneously greater than their respective thresholds, the in-turn pedal application variable is positive;

if the transverse acceleration of the vehicle is less than its respective threshold, the in-turn pedal application variable is negative;

in other cases, the in-turn pedal application variable keeps its value.