Method for controlled braking of a motor vehicle

• US 5,902,019 A
• Filed: 04/30/1997
• Issued: 05/11/1999
• Est. Priority Date: 04/30/1996
• Status: Expired due to Term

• Current Assignee: Continental AG, Ilya Co., Ltd.
• Original Assignee: Continental AG
• Inventors: Prinzler, Hubertus, Maron, Christof, Dieckmann, Thomas
• Primary Examiner(s): Schwartz, Chris
• Application Number:
  US08/841,379
• Time in Patent Office: 741 Days
• Field of Search: 303/9.61, 303/9.71, 303/15, 303/20, 303/113.4, 303/140, 303/155, 303/167-169, 303/173, 303/174, 303/188, 303/189, 303/DIG. 4, 701/72, 701/78, 701/83, 364/426.01, 364/426.016, 364/426.023, 364/426.028
• US Class Current: 303/15
• CPC Class Codes: B60T 13/66 Electrical control in fluid-pressure brake systems
• CPC Class Codes: B60T 13/74 with electrical assistance or drive
• CPC Class Codes: B60T 2270/82 Brake-by-Wire, EHB
• CPC Class Codes: B60T 7/042 by electrical means, e.g. using travel or force sensors
• CPC Class Codes: B60T 8/1764 Regulation during travel on surface with different coefficients of friction, e.g. between left and right sides, mu-split or between front and rear
• CPC Class Codes: B60T 8/1766 Proportioning of brake forces according to vehicle axle loads, e.g. front to rear of vehicle
• CPC Class Codes: B60T 8/18 responsive to vehicle weight or load, e.g. load distribution using electrical circuitry on regulation means B60T8/17; B60T8/30 takes precedence; responsive to weight and speed condition B60T8/58
• CPC Class Codes: B60T 8/24 responsive to vehicle inclination or change of direction, e.g. negotiating bends using electrical circuitry or regulation means B60T8/17
• CPC Class Codes: B60T 8/266 using valves or actuators with external control means B60T8/261 takes precedence
• CPC Class Codes: B60T 8/321 deceleration B60T8/34, B60T8/52, B60T8/54, B60T8/56, B60T8/58, B60T8/72, B60T8/86, B60T8/88 take precedence
• CPC Class Codes: B60T 8/3255 Systems in which the braking action is dependent on brake pedal data

Abstract

The invention relates to a method for providing controlled braking of a motor vehicle and a brake system for carrying out the method. The brake system includes a central unit and brake actuators for each wheel of the motor vehicle. The brake actuators are connected to the central unit. In the central unit, a relative braking-force distribution key is computed at time intervals and is transmitted to the brake actuators. With a braking operation, the absolute braking force for the braking operation is computed in each brake actuator from the corresponding component of the relative braking-force distribution key.

Claims

1. A method for operating an electric brake system of a motor vehicle having a plurality of wheels, the method comprising the steps of:

providing a brake pedal and sensor assembly for generating a pedal signal (S) which defines a total braking force;

providing a plurality of brake actuators for corresponding ones of said wheels;

providing a plurality of computing units operatively connected to respective ones of said brake actuators;

providing a central unit connected to respective ones of said computing units so as to permit said control unit to transmit data to said computing units;

the method further including the following steps which are carried out independently of actuating said electric brake system;

computing a new braking-force distribution key (BS'"'"') in said central unit at time intervals and said braking-force distribution key (BS'"'"') having a plurality of new components (Ki'"'"') assigned to corresponding ones of said brake actuators and each of said new components (Ki'"'"') defining a relative braking force to which the brake actuator assigned thereto is to be controlled to during a braking operation of said electric brake system;

transmitting said new components (Ki'"'"') for said brake actuators, respectively, to corresponding ones of said computing units wherein said new components (Ki'"'"') replace respective old components (Ki) stored therein;

and, when said brake pedal is actuated, the following additional method steps are carried out;

conducting said pedal signal (S) directly to said computing units of said brake actuators, respectively;

in each of said computing units, computing an absolute braking force from a product of the then stored component (Ki'"'"') and said pedal signal (S); and

,

applying the absolute braking force computed in each computing unit to the brake actuator corresponding thereto.

2. The method of claim 1, wherein a new braking-force distribution key (BS'"'"') is periodically computed.

3. The method of claim 1, wherein a new braking-force distribution key (BS'"'"') is computed when a change of the driving situation of said motor vehicle is determined.

4. The method of claim 1, the method comprising the further step of replacing the last stored component (Ki) in each computing unit with a fixed pregiven value when the corresponding new components (Ki'"'"') are not transmitted to said computing units corresponding thereto within a pregiven time span.

5. An electrical brake system for a motor vehicle, the electrical brake system comprising:

a brake pedal and sensor assembly for generating a pedal signal (S) defining a total braking force;

a plurality of brake actuator units for corresponding ones of the wheels of said motor vehicle;

a plurality of computing units operatively connected to respective ones of said brake actuator units;

a central unit for computing a braking-force distribution key (BS);

said central unit being connected to corresponding ones of said computing units for transmitting data thereto;

said central unit functioning to compute a new braking-force distribution key (BS'"'"') having a plurality of new components (Ki'"'"') assigned to corresponding ones of said brake actuators and each of said new components (Ki'"'"') defining a relative braking force to which the brake actuator assigned thereto is to be controlled during a braking action of said electric brake system;

said control unit further functioning to transmit said new components (Ki'"'"') for said brake actuators, respectively, to corresponding ones of said computing units wherein said new components (Ki'"'"') replace respective old components (Ki) stored therein;

each of said computing units having an overwrite memory wherein the new component (Ki'"'"') corresponding to the computing unit can be stored at any time point;

each of said computing units functioning to compute an absolute braking force from a product of the corresponding stored component (Ki'"'"') and said pedal signal (S); and

,

signal line means for transmitting said pedal signal (S) directly to said computing units.