Electronic control unit for controlling the auto-hold function

Abstract

A method and electronic control unit having a functional module are provided for controlling the auto-hold function and the parking brake function in a motor vehicle, by use of a single common operating element. When the parking brake function is switched on at a standstill, the auto-hold function is simultaneously activated. When the accelerator pedal is actuated, a switched-on parking brake function is automatically switched off without the actuation of the operating element, wherein the auto-hold function remains activated. In addition, when switching off the parking brake function at a standstill, the auto-hold function is also deactivated via the actuation of the operating element.

Claims

1. An electronic control unit, comprising: a function module that controls an auto-hold function and a parking brake function in a motor vehicle, wherein the function module is configured so as to receive, as an input signal, an electrical signal of an operator control element for switching the parking brake function on and off, wherein: when the parking brake function is switched on in a stationary state of the motor vehicle via the input signal from the operator control element, the auto-hold function is activatable simultaneously, and when an accelerator pedal is actuated, the switched-on parking brake function is switchable off automatically without actuating the operator control element while at the same time the auto-hold function remains activated or is activated.

2. The electronic control unit as claimed in claim 1, wherein the function module is further configured such that, when the parking brake function is switched off in the stationary state, the auto-hold function is also deactivatable by actuating the operator control element.

3. The electronic control unit as claimed in claim 1, wherein the function module is further configured such that, when the parking brake function is switched off in the stationary state by actuating the operator control element: (i) in the case of single actuation of the operator control element, the parking brake function is switched off and at the same time also the auto-hold function is deactivated, or (ii) when the operator control element is actuated for the first time, firstly the parking brake function is switched off, and when the operator control element is actuated again the auto-hold function is also deactivated.

4. The electronic control unit as claimed in claim 1, wherein the function module is further configured such that, when the parking brake function is switched on in the stationary state by actuating the operator control element: (i) in the case of single actuation of the operator control element, the parking brake function is switched on and at the same time also the auto-hold function is activated, or (ii) when the operator control element is actuated for the first time, firstly the parking brake function is switched on, and when the operator control element is actuated again the auto-hold function is also deactivated.

5. The electronic control unit as claimed in claim 1, wherein the function module is further configured such that, when the operator control element is actuated during travel in a way which causes the parking brake function to be switched on in the stationary state: (i) the auto-hold function is activatable if the actuation of the operator control element is performed in a defined, comparatively short time or if no emergency braking function is connected to the actuation of the operator control element during travel, or (ii) the auto-hold function cannot be activated if an emergency braking function is connected to the actuation of the operator control element during travel, or (iii) the auto-hold function can be activated if the actuation of the operator control element is performed in a defined, comparatively short time and that after the expiry of this time further actuation of the operator control element causes an emergency braking function.

6. A system capable to perform an auto-hold function of a motor vehicle, comprising: an electronic control unit as claimed in claim 1; and an operator control element by which the auto-hold function is activatable and deactivatable in order to switch a parking brake function on and off, wherein the operator control element continues to be used at a same time for switching the parking brake function on and off.

7. A motor vehicle, comprising: a system capable to perform an auto-hold function of a motor vehicle as claimed in claim 6.

8. A method for controlling an auto-hold function and a parking brake function of a motor vehicle, the method comprising the step of: providing a single common operator control element by which the auto-hold and parking brake functions are controllable; and when the single common operator control element is actuated for the first time or after it has been actuated multiple times in order to switch on the parking brake function in a stationary state, the auto-hold function is also activated, and when an accelerator pedal is actuated, the switched-on parking brake function is switchable off automatically without actuating the single common operator control element while at the same time the auto-hold function remains activated or is activated.

9. A method for controlling an auto-hold function and a parking brake function of a motor vehicle via a single common operator control element, the method comprising the steps of: when the parking brake function is switched on in a stationary state by actuating the single common operator control element; (i) in the case of single actuation of the single common operator control element, the parking brake function is switched on and at the same time also the auto-hold function is activated, or (ii) when the single common operator control element is actuated for the first time, firstly the parking brake function is switched on, and when the single common operator control element is actuated again the auto-hold function is also activated, when an accelerator pedal is actuated, the switched-on parking brake function is switchable off automatically without actuating the single common operator control element while at the same time the auto-hold function remains activated or is activated.

10. A method for controlling an auto-hold function and a parking brake function of a motor vehicle via a single common operator control element, the method comprising the steps of: when the parking brake function is switched off in a stationary state by actuating the single common operator control element; (i) in the case of single actuation of the single common operator control element, the parking brake function is switched off and at the same time the auto-hold function is also deactivated, or (ii) when the single common operator control function is actuated for the first time, firstly the parking brake function is switched off, and when the single common operator control element is actuated again the auto-hold function is also deactivated, and when an accelerator pedal is actuated, a switched-on parking brake function is switchable off automatically without actuating the single common operator control element while at the same time the auto-hold function remains activated or is activated.

11. The method as claimed in claim 10, wherein when the parking brake function is switched off in a stationary state by actuating the single common operator control element, the auto-hold function is also deactivated.

12. The method as claimed in claim 11, wherein when the operator control element is actuated during travel in a way which causes the parking brake to be switched on in the stationary state: (i) the auto-hold function is activated if the actuation of the operator control element is performed in a defined, comparatively short time or if no emergency braking function is connected to the actuation of the operator control element during travel, or (ii) the auto-hold function is not activated if an emergency braking function is connected to the actuation of the operator control element during travel, or (iii) the auto-hold function is activated if the actuation of the operator control element is performed in a defined, comparatively short time and that after the expiry of this time further actuation of the operator control element causes an emergency braking function.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic illustration of a motor vehicle having the essential components of the invention.

(2) FIG. 2 shows a possible state transition diagram according to the method according to the invention in a possible variant.

DETAILED DESCRIPTION OF THE DRAWINGS

(3) FIG. 1 illustrates a motor vehicle 1 having an operator control element 4 for switching the parking brake function on and off and having an electronic control unit 2. The electronic control unit 2 has a function module 3, in particular in the form of a software program product, for controlling an auto-hold function and the parking brake function. The function module 3 is programmed in such a way that it receives at least the electrical signals (switch-on signal 1 and switch-off signal 0) of the operator control element 4 for switching the parking brake function on and off and a vehicle speed signal v for detecting a vehicle stationary state as input signals. The actuation signals of the accelerator pedal FP and of the brake pedal BP are also preferably input signals of the control unit 2. The method according to the invention is carried out as a function of at least the vehicle speed v and the actuation signal (0/1) of the operator control element 4.

(4) Both the auto-hold function (AUTO H) and the parking brake function (P) can be controlled by way of the function module 3 in the control unit 2, using the single operator control element 4. In this context, when the parking brake function is switched on in the stationary state (for example when v=0), the auto-hold function is activated at the same time. When the accelerator pedal FP is actuated, the parking brake function is switched off automatically without actuation of the operator control element 4, but the auto-hold function remains activated. When the parking brake function is switched off in the stationary state by actuating the operator control element 4, the auto-hold function is also deactivated.

(5) In one of three possible alternatives, when the operator control element 4 is actuated here during travel (v>0) in a way which causes the parking brake to switch on in the stationary state (e.g. by pulling a pull/push key 4 or switch-on signal 1), the auto-hold function (AUTO H) is activated if the actuation of the operator control element 4 is performed in a defined, comparatively short time dt1 and ended again, wherein after the expiry of this time dt1 further actuation of the operator control element causes an emergency braking function (EMERGENCY BRAKING).

(6) In particular, this method is also explained below in more detail in a tabular form on the basis of an exemplary embodiment according to FIG. 2 by way of a state diagram.

(7) In this context, in FIG. 2 the system state auto-hold function activated is abbreviated to auto hold, and the system state parking brake function switched on is abbreviated to EMF. The term present is understood to mean a vehicle state in which the driver is present in the vehicle but has not yet started the drive engine. The term DRIVE stationary is understood to mean a vehicle state in which the vehicle is still present in the stationary state but the drive engine has already started. The term DRIVE travel is understood to mean a vehicle state in which the vehicle is no longer present in the stationary state (v>0).

(8) Press EMF corresponds to the actuation of the operator control element 4 in order to switch off 0 the parking brake function. Pull EMF corresponds to the actuation of the operator control element 4 in order to switch on 1 the parking brake function. The abbreviation SST indicates the starting or stopping of the drive engine.

(9) Finally, on the following pages the state transitions are compiled in a table:

(10) TABLE-US-00001 Initial System Vehicle Control state state state operation Action Target state 1 EMF PRESENT Press SST* Setup 3 DRIVE 2 PRESENT Press SST* Setup 5 DRIVE Pull EMF Pull EMF 1 3 EMF DRIVE Press SST End DRIVE 1 stationary Press EMF* Release 5 EMF Start Release 6 EMF Activate Auto-H 4 Auto-H DRIVE Press SST End DRIVE, 1 stationary pull EMF Press EMF* Deactivate 5 Auto-H Pull EMF Pull EMF 3 Start 6 5 DRIVE Press SST End DRIVE 2 stationary Pull EMF Activate 4 Auto-H Start 7 6 Auto-H DRIVE SST 5x Engine 2 travel emergency off Pull EMF Emergency 1 braking Press EMF Deactivate 7 Auto-H Stop 4 7 DRIVE SST 5x Engine 2 travel emergency off Pull EMF Emergency 1 braking Stop 5 *and press brake pedal BP

(11) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.