DE102011005320A1 - Method for operating motor vehicle, involves activating sail mode if the brake pedal operation amount is smaller than the threshold value - Google Patents

Abstract

The method involves controlling operation of an internal combustion engine (1) by an engine control device (6). The internal combustion engine is connected to an output unit (2) through a gear transmission system (3). The internal combustion engine is uncoupled from output unit by an internal shifting unit (4) provided in gear transmission system during sail mode. The sail mode is activated if the brake pedal operation amount is smaller than the threshold value. An independent claim is included for transmission control device of automatic or automated gear transmission system.

Description

The invention relates to a method for operating a motor vehicle according to the preamble of claim 1. Furthermore, the invention relates to a transmission control device for carrying out the method.

From the DE 10 2008 029 453 A1 For example, a method for operating a motor vehicle having an internal combustion engine and a transmission connected between the internal combustion engine and an output is known. From this state of the art it is known, while driving the motor vehicle depending on defined operating conditions to separate the engine from the output, so as to operate the motor vehicle in a sailing mode. For this purpose, at least one internal or external gear shifting element or starting element can be opened, so that the internal combustion engine is decoupled from the output. The procedure according to DE 10 2008 029 453 A1 uses to activate the sailing mode a tactile intermediate positions of an accelerator pedal and / or a brake pedal that can be felt by a driver. Furthermore, it is from the DE 10 2008 029 453 A1 known that from a driver assistance system such. B. a cruise control system or distance control system out of the sailing mode can be activated.

Proceeding from this, the present invention is based on the object to provide a novel method for operating a motor vehicle and a novel transmission control device.

This object is achieved by a method according to claim 1. According to the invention, when during driving of the motor vehicle with running, coupled to the output engine on the one hand, a current driver's request torque dependent on a driver's accelerator pedal operation or a current driving torque predetermined by a driver assistance system for a defined time in a defined range and on the other hand the current vehicle acceleration or vehicle deceleration of the motor vehicle is within a defined range, the sailing mode activated.

The method according to the invention proposes a completely novel strategy for activating the sailing mode for a motor vehicle. With the invention, it is possible for a sailing mode to be used more frequently so as to provide and utilize a further fuel economy potential. Since the sailing function can also be used when the accelerator pedal is actuated, the driving behavior of the motor vehicle can be better matched to a driver's request when sailing. As a result, the driver-side acceptance of the sailing mode can be increased.

According to an advantageous development, if the amount of the driver's desired torque or the amount of the driving torque is reduced by more than a limit value and / or the vehicle acceleration by more than a limit value when the amount of the driver's desired torque or driving torque is valid when the sailing mode is activated increases, the sailing mode deactivated. Then, when in active sail mode, the amount of the driver's desired torque or the amount of driving torque compared to the valid on activation of the sailing mode amount of the driver's desired torque or the driving torque increased by more than a limit and / or a change from sub-operation to train operation, the sailing mode also deactivated. Such deactivation of the sailing mode depending on the amount of the driver's desired torque or amount of the driving torque in comparison to the valid on activation of the sailing mode amount of the driver's desired torque or driving torque is particularly preferred because it is thereby possible, the driving behavior. the motor vehicle in the sailing function to the driver's request easily and with a high driver's acceptance to adapt.

According to a further advantageous development, when the sail mode is active, a gradient of the reduction of the driver's desired torque or the driving torque is smaller than a limit value and furthermore the vehicle acceleration is smaller than a limit value, the sailing mode remains activated, whereas if the gradient of the reduction of the driver's desired torque or the driving torque is greater than a threshold and / or the vehicle acceleration is greater than a threshold, the sailing mode is deactivated.

Then, with the sailing mode active, a gradient of increasing the driver command torque or torque is less than a threshold, the sail mode remains active, whereas if the gradient of increasing the driver command torque or torque is greater than a threshold, the sail mode is disabled.

The deactivation of the sailing mode depending on the gradient of the change in the driver's request also allows a simple adaptation of the sailing function to the driver's request and thus a high driver's acceptance of the sailing mode.

Vorzugswelse different thresholds for the respective amounts and / or the respective gradients are used for the driving torque and the driver's desired torque. Then, if for the respective amounts and / or respective Gradients of driver's desired torque and driver's torque are kept different limits, a further improvement of the driving behavior of the motor vehicle in sailing mode in terms of high driver acceptance is possible.

Preferred embodiments of the invention will become apparent from the dependent claims and the description below. Embodiments of the invention will be described, without being limited thereto, with reference to the drawings.

Showing:

1 a diagram of a first motor vehicle, in which the inventive method for operating a motor vehicle can be used; and

2 a diagram of a second motor vehicle, in which the inventive method for operating a motor vehicle can be used.

The present invention relates to a method for operating a motor vehicle and can in particular in the in 1 and 2 schematically illustrated motor vehicles are used. 1 and 2 show each driveline schemes of motor vehicles that use an internal combustion engine 1 and one between the combustion engine 1 and a downforce 2 switched gear 3 include. In the transmission 3 is it in 1 and 2 each automatic or automated manual transmission with multiple switching elements 4 , which can be designed as clutches and / or brakes.

Then, when the motor vehicle is a hybrid vehicle, the drive unit of the motor vehicle comprises in addition to the internal combustion engine 1 at least one electric machine.

According to 1 and 2 becomes the operation of the automatic or automated transmission 3 from a transmission control device 5 controlled and / or regulated. The operation of the internal combustion engine 1 is from a motor control device 6 controlled and / or regulated. The transmission control device 5 exchanges with the gearbox 3 and the engine control device 6 with the internal combustion engine 1 in the sense of the dashed arrows data from. Similarly, change the transmission control device 5 and the engine control device 6 with each other data.

In the powertrain of 1 serves one of the internal gear shift elements 4 as starting element. In the powertrain of 2 is a separate, external drive-off element 7 available.

The present invention relates to a method for operating such a motor vehicle in sailing mode, wherein in the sailing mode of the internal combustion engine 1 from the downforce 2 disconnected. When the motor vehicle 1 This can be done by one of the internal gear shift elements 4 is open and the power flow or torque flow from the internal combustion engine 1 to the downforce 2 interrupts. When the motor vehicle 2 For this purpose, the gear-external starting element 7 to be open.

Already at this point it should be noted that in sailing mode, that is, when the internal combustion engine 1 from the downforce 2 disconnected, the internal combustion engine 1 in an idle speed, in particular in a defined lowered idle speed, can be operated that optionally cylinder of the current internal combustion engine 1 can be switched off or that alternatively in sailing mode of the internal combustion engine 1 can also be completely shut down. In sailing mode, therefore, the internal combustion engine 1 completely running, partially shut down by a cylinder deactivation or completely shut down.

Then, if a motor vehicle while driving not in sailing mode, so with running, to the output 2 coupled combustion engine 1 operated. is, and if on the one hand depends on a driver side accelerator pedal operation, current driver's desired torque or predetermined by a driver assistance system, current driving torque for a defined time in a defined range, and if on the other hand, the current vehicle acceleration or vehicle deceleration of the motor vehicle is within a defined range, According to the invention, the sail mode is activated, what then on the one hand in 1 one of the switching elements 4 or in 2 the starting element 7 is controlled so that the internal combustion engine 1 from the downforce 2 is decoupled, and on the other hand, the internal combustion engine 1 is controlled so that the same operated in sailing mode either with a defined idle speed and / or partially shut down via a cylinder deactivation or completely stopped. This control of the switching element 4 or starting element 7 and the internal combustion engine 1 is from the transmission control device 5 predetermined, wherein the transmission control device 5 the switching element 4 or starting element 7 directly and the internal combustion engine 1 indirectly via the engine control device 6 controls.

The driver's desired torque is the torque that depends on a current accelerator operation and, if appropriate, on a current driving program, such as a sports driving program or comfort Driving program, is determined and therefore the driver side is affected by pressing an accelerator pedal.

The driving torque is a torque that is automatically determined and predetermined by a driver assistance system, such as a cruise control system or a distance control system.

Then, when both a driver's desired torque and a driving torque are present, that moment is determined and used for the inventive method in terms of a maximum selection, which is greater.

If the driver's desired torque is greater than the driving torque, the method is carried out on the basis of the driver's desired torque. If the driving torque is greater than the driver's desired torque, the method is carried out on the basis of the driving torque.

The inventive entry or activation of the sailing mode according to the invention takes place when, on the one hand, the current driver's desired torque or the current driving torque is within a defined range for a defined time and, on the other hand, if the current vehicle acceleration or vehicle deceleration is within a defined range. This makes it possible to use the sailing function even when an accelerator operation is present.

Then, when the vehicle is operated in active sail mode and when active sail mode, the amount of the driver's desired torque or the amount of torque compared to the valid on activation of the sailing mode amount of the driver's desired torque or the driving torque reduced by more than a limit and / or the vehicle acceleration to increases more than a limit, the sailing mode is deactivated.

If, on the other hand, the reduction of the driver's desired torque or driving torque remains below the respective limit value and furthermore the increase of the vehicle acceleration is below the respective limit value, the sailing mode is maintained.

Then, when in the active sailing mode, the amount of the driver's desired torque or the amount of driving torque over the valid on activation of the sailing mode amount of the driver's desired torque or the driving torque increases by more than a limit and / or if a change from overrun to train operation, the sailing mode automatically deactivated.

However, if this increase or increase in the driver's desired torque or driving torque in overrun or train operation without change from overrun to train operation is less than the respective limit, the sail mode is maintained and therefore active.

Then, when the sailing mode is active, with the sailing mode active, an exit from the sailing mode depending on the gradient of the driver's desired torque or driver's torque can continue. Thus, it may be provided that when in active sail mode, a gradient of the reduction of the driver's desired torque or the driving torque is smaller than a limit value and further, if the vehicle acceleration is less than a limit value, the sailing mode remains active, whereas if the gradient of the reduction the driver request torque or the driver torque is greater than the limit value and / or the vehicle acceleration is greater than the corresponding limit value, the sailing mode is deactivated.

Furthermore, it can be provided that, when the sailing mode is active, when a gradient of the increase of the driver's desired torque or of the driving torque is smaller than a limit value, the sailing mode remains active, whereas if the gradient of the increase of the driver's desired torque or of the driving torque is greater than a limit value The sailing mode is deactivated.

All of the above limits may be subject to hysteresis offset values to avoid undesirable frequent switching between enabling and disabling the sail mode.

According to a further advantageous embodiment of the invention, it is provided that in an active sailing mode, when an amount of brake pedal operation and a gradient of the brake pedal operation is smaller than a limit value, the sailing mode remains active. Then, on the other hand, if the amount of brake pedal operation and / or the gradient of the brake pedal operation is greater than the respective limit value, the sail mode is automatically deactivated. This makes it possible to continue to use the sailing mode even when the brake pedal is pressed. These limit values can also be subjected to hysteresis offset values.

As already stated, the method is carried out either using the driver's desired torque, which is determined as a function of an accelerator operation, or depending on the driving torque, which is specified by a driver assistance system. For the corresponding limit values of the driving torque or the driver's desired torque with regard to the change in the amount the same or with respect to the gradient thereof, different limit values may be present, so that different parameter sets are used for the limit values, depending on whether the method is carried out on the basis of the driver's desired torque or on the basis of the driving torque.

The inventive method is by the transmission control device 5 carried out. The transmission control device 5 can this directly the gear 3 with the switching elements 4 or the starting element 7 as well as indirectly via the engine control device 6 the internal combustion engine 1 drive. The evaluation of the driver's desired torque or driving torque and the comparison with the corresponding limit values takes place in the transmission control device 5 ,

Then, when the method of the present invention evaluates and utilizes vehicle acceleration or deceleration, that vehicle acceleration or deceleration may be a value measured by an acceleration sensor or deceleration sensor, or alternatively one of speed changes of the transmission output or output 2 act calculated value.

With the aid of the method according to the invention, it is possible to activate a sailing function even when the accelerator pedal is low and, in the activated state, also to be used when the accelerator pedal is pressed or, if necessary, the brake pedal is actuated.

In a sailing mode, the reaction or the behavior of the motor vehicle can be better matched to a driver's request, so that a driver's acceptance of a sailing function or a sailing mode can be increased.

There can be provided and used another fuel saving potential.

LIST OF REFERENCE NUMBERS

1

Power unit / engine

2

output

3

transmission

4

switching element

5

Transmission control device

6

Motor controller

7

starting element

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008029453 A1 [0002, 0002, 0002]

Claims (12)

Method for operating a motor vehicle, which has an internal combustion engine ( 1 ) and one between the internal combustion engine ( 1 ) and an output ( 2 ), automatic or automated transmission ( 3 ), while driving the motor vehicle with running, to the output ( 2 ) coupled internal combustion engine ( 1 ) in the presence of at least one defined operating condition at least one internal or external gear shift element ( 4 ) or starting element ( 7 ) is opened at least so far that for providing a sailing mode of the internal combustion engine ( 1 ) from the output ( 2 ) is decoupled, characterized in that when, while driving the motor vehicle with running, to the output ( 2 ) coupled internal combustion engine ( 1 On the one hand, a current driver's desired torque dependent on a driver-side accelerator pedal actuation or a current driver torque defined by a driver assistance system lies within a defined range for a defined time and, on the other hand, the current vehicle acceleration or vehicle deceleration is within a defined range, the sail mode is activated. A method according to claim 1, characterized in that when the sailing mode is activated, on the one hand, a switching element ( 4 ) or a starting element ( 7 ) is controlled so that the internal combustion engine ( 1 ) from the output ( 2 ) and, on the other hand, the internal combustion engine ( 1 ) is driven so that it is operated either with a defined Leelaufdrehzahl and / or partially stopped by a cylinder deactivation or completely stopped. A method according to claim 1 or 2, characterized in that when the sailing mode is active, the amount of the driver's desired torque or the amount of the driving torque compared to the valid on activation of the sailing mode amount of the driver's desired torque or the driving torque reduced by more than a limit and / or the Vehicle acceleration increases by more than a limit, the sailing mode is disabled. Method according to one of claims 1 to 3, characterized in that when active sailing mode, the amount of the driver's desired torque or the amount of driving torque over the valid upon activation of the sailing mode amount of the driver's desired torque or the driving torque increased by more than a limit and / / or a change from sub-operation to train operation, the sailing mode is deactivated. Method according to one of claims 1 to 4, characterized in that when in active sail mode, a gradient of the reduction of the driver's desired torque or the driving torque is less than a threshold value and further, the vehicle acceleration is less than a threshold value, the sail mode remains activated, whereas if the gradient of the reduction of the driver command torque or the driving torque is greater than a limit value and / or the vehicle acceleration is greater than a limit value, the sailing mode is deactivated. Method according to one of claims 1 to 5, characterized in that when active sail mode, a gradient of the increase of the driver's desired torque or the driving torque is less than a threshold value, the sailing mode remains activated, whereas, when the gradient of increasing the driver's desired torque or of the driving torque is greater than a limit value, the sailing mode is deactivated. Method according to one of claims 1 to 6, characterized in that the driver's desired torque is determined depending on a driver-side accelerator operation and, where appropriate, depending on a selected driving program. Method according to one of claims 1 to 7, characterized in that the driving torque is predetermined by a driver assistance system, wherein between the driver's desired torque and the driving torque, a maximum selection is made. Method according to one of claims 1 to 8, characterized in that when in active sail mode, an amount of brake pedal operation is less than a threshold, the sailing mode remains activated, whereas, when the amount of brake pedal operation is greater than a limit, the sailing mode is deactivated. Method according to one of claims 1 to 9, characterized in that when in active sail mode, a gradient of the brake pedal operation is less than a threshold value, the sailing mode remains activated, whereas, when the gradient of the brake pedal operation is greater than a limit, the sailing mode is deactivated. Method according to one of claims 1 to 10, characterized in that in each case different limit values are used for the driving torque and the driver's desired torque. Transmission control device of an automatic or automated transmission, characterized in that it carries out the method according to one of claims 1 to 11.

Images