Method and device for detecting a panic braking operation

• US 20020027389A1
• Filed: 07/02/2001
• Published: 03/07/2002
• Est. Priority Date: 06/30/2000
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Diehle, Stefan, Poggenburg, Ruediger, Opferkuch, Thomas, Ullmann, Steffen
• Granted Patent: US 6,623,090 B2
• Time in Patent Office: Days
• US Class Current: 303/177
• CPC Class Codes: B60T 2201/03 Brake assistants
• CPC Class Codes: B60T 2270/413 Plausibility monitoring, cross check, redundancy
• CPC Class Codes: B60T 2270/416 Wheel speed sensor failure
• CPC Class Codes: B60T 7/12 for automatic initiation; for initiation not subject to will of driver or passenger limiting speed of vehicles other than rail vehicles B60K31/00
• CPC Class Codes: B60T 8/3275 Systems with a braking assistant function, i.e. automatic full braking initiation in dependence of brake pedal velocity
• CPC Class Codes: B60T 8/885 using electrical circuitry
• CPC Class Codes: Y10S 188/01 Panic braking

Abstract

A panic braking operation of a vehicle having at least two wheels is detected by measuring speed quantities which represent the rotary motions of at least two wheels, selecting the speed quantity of one of the wheels and/or by determining a speed value from the speed quantities, determining a change value which represents the time-related change of the selected speed quantity and/or of the speed value, determining the time characteristic of the change value, and detecting a panic braking operation as a function of the time characteristic of the change value. What is advantageous here is that no complex and expensive additional sensor technology is needed for detecting panic braking; the wheel-speed sensors which are provided anyway in anti-lock control systems, traction control systems, and/or vehicle stability control systems are sufficient. Thus, the use of a panic detection is also possible in so-called “low-cost braking systems”.

Claims

1. A method for detecting a panic braking operation of a vehicle having at least two wheels, comprising the steps of:

measuring speed quantities that represent rotary motions of the at least two wheels;

performing at least one of the steps of;

selecting one of the speed quantities corresponding to one of the at least two wheels, and

determining a speed value from the speed quantities;

determining a change value representing a time-related change of at least one of the selected speed quantity and the speed value;

determining a time characteristic of the change value; and

detecting a panic braking operation as a function of the time characteristic of the change value.

2. The method according to claim 1, wherein:

the speed value of one of the at least two wheels is selected such that at least one of the following occurs;

one of the speed quantities corresponding to one of the at least two wheels having a lowest rotational speed is selected as the selected speed quantity, and

the speed value is determined via a mean value generation from the speed quantities of the at least two wheels.

3. The method according to claim 1, further comprising the steps of:

checking the speed quantities for errors; and

excluding those of the speed quantities corresponding to those of the at least two wheels at which an error has been detected from at least one of the selecting of the speed quantity and the determining of the speed value.

4. The method according to claim 1, further comprising the steps of:

detecting whether the vehicle travels on a roadway having irregularities of a specifiable degree; and

deactivating the detecting of the panic braking operation when the vehicle is detected as traveling on the roadway having irregularities.

5. The method according to claim 1, wherein:

the vehicle includes an engine that drives at least one of the at least two wheels, and

only nondriven wheels are used for at least one of the selecting the selected speed quantity and for determining the speed value.

6. The method according to claim 1, further comprising the steps of:

comparing the change value to a first threshold value;

detecting the panic braking operation if the change value falls below a second threshold value within a specifiable first period of time subsequent to falling below the first threshold value, the first threshold value being greater than the second threshold value.

7. The method according to claim 1, further comprising the steps of:

detecting a braking signal representing an actuation of a brake pedal of the vehicle that can be actuated by a driver; and

performing at least one of the steps of;

detecting the panic braking operation only if the braking signal indicates the actuation of the brake pedal, and

performing the steps of;

determining a deceleration quantity representing a deceleration of the vehicle, and

detecting the panic braking operation only if the deceleration quantity becomes greater over time.

8. The method according to claim 1, wherein, in response to a detection of the panic braking operation, the method further comprises at least one of the steps of:

activating a hazard warning system provided in the vehicle, and

limiting a brake pressure at rear wheels of the at least two wheels, wherein one of the following occurs;

the limiting of the brake pressure is maintained until at least one of an anti-lock control and a braking-force distribution control is activated at the rear wheels,

a specifiable second period of time is exceeded, and

a specifiable minimum vehicle deceleration is undershot.

9. A device for detecting a panic braking operation of a vehicle having at least two wheels, comprising the steps of:

an arrangement for measuring speed quantities that represent rotary motions of the at least two wheels;

an arrangement including at least one of;

an arrangement for selecting one of the speed quantities corresponding to one of the at least two wheels, and

an arrangement for determining a speed value from the speed quantities;

an arrangement for determining a change value representing a time-related change of at least one of the selected speed quantity and the speed value;

an arrangement for determining a time characteristic of the change value; and

an arrangement for detecting a panic braking operation as a function of the time characteristic of the change value.

10. The device according to claim 9, wherein:

the speed value of one of the at least two wheels is selected such that at least one of the following occurs;

one of the speed quantities corresponding to one of the at least two wheels having a lowest rotational speed is selected as the selected speed quantity, and

the speed value is determined via a mean value generation from the speed quantities of the at least two wheels.

11. The device according to claim 9, further comprising:

an arrangement for checking the speed quantities for errors; and

an arrangement for excluding those of the speed quantities corresponding to those of the at least two wheels at which an error has been detected from at least one of the selecting of the speed quantity and the determining of the speed value.