Control unit for a recuperative brake system of a vehicle and method for braking a vehicle

Patent metadata

Field	Value
Publication number	US-9586486-B2
Application number	US-201414271651-A
Country	US
Kind code	B2
Filing date	May 7, 2014
Priority date	May 13, 2013
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A control device for a recuperative braking system of a vehicle includes: an actuating device configured to (i) select the maximum value of a front axle generator braking torque and of a rear axle generator braking torque, taking into account at least one provided default variable concerning a setpoint total braking torque which is predefined by a driver, (ii) control an electric motor, and (iii) control a hydraulic front axle brake circuit component and a hydraulic rear axle brake circuit component in such a way that a front axle brake pressure and a rear axle brake pressure are settable in such a way that a difference between a predefined setpoint braking torque distribution and an actual braking torque distribution present between the front axle and the rear axle is minimized.

First claim

What is claimed is:

1. A control device for a recuperative braking system of a vehicle, comprising:
an actuating device configured to:
control at least one electric motor of the vehicle, taking into account at least one provided default variable concerning a setpoint total braking torque which is predefined by a driver, in such a way that at least a front axle generator braking torque is applied to a front axle of the vehicle with the aid of the at least one electric motor;
select the maximum permissible front axle generator braking torque which may be applied to the front axle with the aid of the at least one electric motor, and select the maximum permissible rear axle generator braking torque which may be applied to a rear axle of the vehicle with the aid of the at least one electric motor, taking into account at least the default variable, and control the at least one electric motor with the aid of at least one motor control signal to perform a regenerative braking; and
control at least one hydraulic front axle brake circuit component of a front axle brake circuit associated with the front axle, and control at least one hydraulic rear axle brake circuit component of a rear axle brake circuit associated with the rear axle, with the aid of at least one hydraulic control signal and in conjunction with the regenerative braking, in such a way that a front axle brake pressure in the front axle brake circuit and a rear axle brake pressure in the rear axle brake circuit are set in such a way that a difference between (i) a predefined setpoint braking torque distribution and (ii) an actual braking torque distribution present between the front axle and the rear axle is minimized, wherein the actuating device is configured to maintain the setpoint braking torque distribution during the regenerative braking;

wherein the actuating device is configured to select the maximum permissible front axle generator braking torque and the maximum permissible rear axle generator braking torque such that a sum of the maximum permissible front axle generator braking torque and the maximum permissible rear axle generator braking torque is less than or equal to the setpoint total braking torque.

2. The control device as recited in claim 1 , wherein each of the predefined setpoint braking torque distribution and the actual braking torque distribution present between the front axle and the rear axle represents a quotient of (i) a total front axle braking torque exerted on the front axle including the front axle generator braking torque and a front axle friction braking torque exerted on the front axle with the aid of at least one front axle wheel brake cylinder, and (ii) a total rear axle braking torque exerted on the rear axle including the rear axle generator braking torque and a rear axle friction braking torque exerted on the rear axle with the aid of at least one rear axle wheel brake cylinder.

3. The control device as recited in claim 2 , wherein the at least one hydraulic front axle brake circuit component is at least one electromechanical plunger of the front axle brake circuit, and wherein the at least one hydraulic rear axle brake circuit component is at least one electromechanical plunger of the rear axle brake circuit.

4. The control device as recited in claim 2 , wherein the at least one hydraulic front axle brake circuit component is at least one shutoff valve of the front axle brake circuit via which the front axle brake circuit is connected to a main brake cylinder of the braking system, and wherein the at least one hydraulic rear axle brake circuit component is at least one shutoff valve of the rear axle brake circuit via which the rear axle brake circuit is connected to the main brake cylinder of the braking system.

5. The control device as recited in claim 2 , wherein the at least one hydraulic front axle brake circuit component is at least one pressure relief valve of the front axle brake circuit via which the front axle brake circuit is connected to a brake fluid reservoir of the braking system, and wherein the at least one hydraulic rear axle brake circuit component is at least one pressure relief valve of the rear axle brake circuit via which the rear axle brake circuit is connected to the brake fluid reservoir of the braking system.

6. The control device as recited in claim 2 , wherein the at least one hydraulic front axle brake circuit component is at least one pump of the front axle brake circuit which pumps brake fluid from a brake fluid reservoir of the braking system into the front axle brake circuit, and wherein the at least one hydraulic rear axle brake circuit component is at least one pump of the rear axle brake circuit which pumps brake fluid from the brake fluid reservoir of the braking system into the rear axle brake circuit.

7. The control device as recited in claim 2 , wherein the at least one electric motor is a shared generator of the front axle and of the rear axle.

8. The control device as recited in claim 2 , wherein the at least one electric motor includes a front axle generator of the front axle and a rear axle generator of the rear axle.

9. A recuperative braking system for a vehicle, comprising:
a front axle brake circuit associated with the front axle;
a rear axle brake circuit associated with the rear axle; and
a control device configured to:
control at least one electric motor of the vehicle, taking into account at least one provided default variable concerning a setpoint total braking torque which is predefined by a driver, in such a way that at least a front axle generator braking torque is applied to a front axle of the vehicle with the aid of the at least one electric motor;
select the maximum permissible front axle generator braking torque which may be applied to the front axle with the aid of the at least one electric motor, and select the maximum permissible rear axle generator braking torque which may be applied to a rear axle of the vehicle with the aid of the at least one electric motor, taking into account at least the default variable, and control the at least one electric motor with the aid of at least one motor control signal to perform a regenerative braking; and
control at least one hydraulic front axle brake circuit component of the front axle brake circuit associated with the front axle, and control at least one hydraulic rear axle brake circuit component of the rear axle brake circuit associated with the rear axle, with the aid of at least one hydraulic control signal and in conjunction with the regenerative braking, in such a way that a front axle brake pressure in the front axle brake circuit and a rear axle brake pressure in the rear axle brake circuit are set in such a way that a difference between (i) a predefined setpoint braking torque distribution and (ii) an actual braking torque distribution present between the front axle and the rear axle is minimized, wherein the control device is configured to maintain the setpoint braking torque distribution during the regenerative braking;

wherein the actuating device is configured to select the maximum permissible front axle generator braking torque and the maximum permissible rear axle generator braking torque such that a sum of the maximum permissible front axle generator braking torque and the maximum permissible rear axle generator braking torque is less than or equal to the setpoint total braking torque.

10. The recuperative braking system as recited in claim 9 , wherein:
the front axle brake circuit is non-decoupleably connected to a main brake cylinder of the braking system together with at least one electromechanical plunger as the at least one front axle brake circuit component; and
the rear axle brake circuit is (i) deco

Assignees

• Bosch Gmbh Robert

Inventors

• Kunz Michael
• Strengert Stefan

Classifications

• B60T13/745

  acting on a hydraulic system, e.g. a master cylinder · CPC title

• B60L7/18

  Controlling the braking effect (B60L7/12, B60L7/14, B60L7/16 take precedence) · CPC title

• B60T13/586

  the retarders being of the electric type · CPC title

• B60T8/4072

  Systems in which a driver input signal is used as a control signal for the additional fluid circuit which is normally used for braking · CPC title

• B60L7/26 Primary

  Controlling the braking effect · CPC title