DE102010033853A1 - Method for starting assistance of a vehicle - Google Patents

Abstract

The present invention relates to a method for starting support for a vehicle with a clutch, which is arranged between an engine and a drive train, wherein a starting situation is detected and, when the starting situation is detected, an additional torque or a torque reserve is requested from the engine, a position of a clutch pedal being detected is, depending on the position of the clutch pedal, a value, in particular a pilot control value for the additional torque is determined and used for the control of the engine.

Description

The invention relates to a method for starting assistance of a vehicle according to claim 1.

Various systems for starting assistance of a motor vehicle are known in the prior art. For example, describes DE 10 2006 033 025 A1 a method for operating an internal combustion engine of a motor vehicle, wherein the motor vehicle has a manual transmission with a clutch and a driver-operable clutch pedal. A torque output at the output of the clutch is detected. The torque is compared to a threshold and a start-up controller is activated when the torque reaches the threshold. In the described method, a binary clutch signal is used which detects the position of the clutch pedal. Alternatively, as a sensor, for example, a potentiometer may be provided, from the output signal then directly the coupling signal is derived.

Out DE 102 43 143 B4 For example, a method and a system for starting assistance of motor vehicles are known. In this case, an engine control is provided, which counteracts upon detection of a starting situation by means of an idling control device of a falling engine speed. If a starting situation is detected, an existing driver request is interpreted as a desired engine speed and a suitable engine torque is made available by activating the idling control device.

The object of the invention is to provide an improved method for starting assistance for a motor vehicle.

The object of the invention is achieved by the method according to claim 1.

Further advantageous embodiments of the invention are specified in the dependent claims.

The method according to the invention has the advantage that the starting assistance is performed more precisely. This is achieved by detecting the position of the clutch and depending on the position of the clutch, a pilot value for the additional torque is determined and the pilot value for the additional torque is used for the control of the engine.

In this way, not only a starting situation is detected or not, but the starting assistance is performed depending on the position of the clutch. For a simple and fast method, a pilot value for the additional torque is used.

In one embodiment, the pre-control value is used to drive the motor to provide a torque reserve. Thus, a torque reserve is built up by the activation of the engine even before the need to be provided additional torque. As a result, the additional torque can be provided faster in actual need.

In a further embodiment, the precontrol value is determined as a function of the position of the clutch pedal. This offers the advantage that the actual position of the coupling itself does not have to be detected. Thus, the method is easy to execute.

In a further embodiment, the precontrol value is determined as a function of the rotational speed of the engine. This achieves a more precise adaptation of the pilot value for the additional torque.

In a further embodiment, an adaptation value for the precontrol value is used, wherein the adaptation value is adapted during operation of the motor vehicle. In this way it is achieved that a change in the operation of the clutch or the engine, in particular an aging of the clutch and / or the engine is taken into account in the starting assistance.

In a further embodiment, the adaptation value is determined as a function of a rotational speed behavior of the engine when starting the vehicle. The determination of the pilot value depending on the speed behavior of the motor provides a precise adjustment of the required additional torque for the starting assistance.

In a further embodiment, the precontrol value is adapted such that an additional torque is provided as from the occurrence of a negative gradient of the engine speed. Thus, a timely control of the engine is achieved.

In another embodiment, the pilot value is set in such a way that a maximum pilot value is present at the time of a maximum / negative gradient of the engine speed. This achieves an efficient use of the additional torque for the starting assistance.

In a further embodiment, the pre-control value is adapted such that the pre-control value at the time falls back to the value 0 at which the engine speed during the starting situation has a minimum value and rises again. This means that when the price rises again Engine speed during a startup process no pre-control value is used. This enables efficient control of the engine.

In a further embodiment, the pilot control value is dependent on a difference in the engine speed before and during the starting situation. Preferably, a maximum value for the pre-control value is determined depending on a maximum difference in the engine speed before and during the starting situation. Even with this, a precise adjustment of the additional torque is possible.

In a further embodiment, the actuating speed of the clutch, in particular of the clutch pedal, is taken into account in the determination of the precontrol value. Thus, a precise adjustment of the required pilot control value is possible depending on the dynamics of the clutch.

In a further embodiment, the pilot control value is determined as a function of an active or inactive idle speed controller. In this way, the pilot control value is adapted to an active or inactive idle speed controller, which also supports a stabilization of the speed during a starting situation.

In a further embodiment, a maximum value for the pre-control value of the additional torque or a time integral for the pre-control value of the additional torque is determined during a starting operation. In this way, a malfunction of the control of the motor during a startup process is limited.

The invention will be explained in more detail below with reference to FIGS. Show it

1 a schematic representation of a motor vehicle;

2 a schematic program flow;

3 a diagram for the additional torque depending on the opening position of the clutch; and

4 a speed behavior of the engine depending on the opening position of the clutch.

1 shows a schematic representation of a vehicle 1 that a motor 2 , For example in the form of an internal combustion engine having. The motor 2 is about a clutch 3 with a powertrain 4 connected, for example, via a gear wheels 5 of the vehicle 1 drives. Furthermore, a control unit 6 provided that via control / sensor cables 7 with the engine 2 connected is. In addition, the controller 6 over a second line 8th with a position sensor 9 connected. The position sensor 9 is the clutch 3 assigned and determines the opening position of the clutch 3 , In this case, the closed position of the clutch 3 at least in more than two stages, ie in more stages than open or closed. For example, at least one or more intermediate positions can be detected between open and closed. In addition, preferably, a stepless open position of the clutch 3 , in particular in the form of an analog measurement signal, are detected.

The control unit 6 is with a data store 15 connected. There is also a clutch pedal 10 provided, which is actuated for actuating the clutch by a driver. The clutch pedal 10 is a sensor 11 assigned, via a line 12 with the control unit 6 connected is. The sensor 11 detects, for example, in steps or continuously the position of the clutch pedal 10 , In addition, the sensor can 11 be formed, the operating speed of the clutch pedal 10 to capture and to the control unit 6 to be able to forward. The position of the clutch pedal 10 and the operating speed of the clutch pedal 10 can be used as a measure of the position of the clutch 3 or the actuation speed of the clutch 3 be used. The control unit 6 also records via the control / sensor lines 7 and other not shown sensors further operating parameters of the internal combustion engine, such as. B. the speed of the engine. In addition, the controller 6 via a third line 13 with a speedometer 14 connected to the speed of the vehicle 1 detected.

The control unit 6 is trained to the engine 2 , In particular, an injection system for fuel to control in such a way that the engine outputs a torque corresponding to the driver's request. For this purpose, a corresponding control program in the data memory 15 stored.

The control unit 6 is over a fourth line 16 with a second sensor 17 connected to an accelerator pedal 18 assigned. The gas pedal 18 is used by a driver to deliver a driver's request. With the help of the second sensor 17 detects the control unit 6 about the position and / or the operating speed of the accelerator pedal 18 the driver's request 18 ,

Based on the program flow of the 2 the operation of the control device and the method for assisting in starting the vehicle is explained in more detail.

At program point 100 is the engine 2 for example, at idle and the controller 6 Checks whether a starting situation with actuated clutch, ie, an at least partially open clutch exists. For example, this is the speed of the vehicle 1 with the help of the speedometer 14 detected and actuation of the clutch, for example, directly via the first sensor 9 or about the position of the clutch pedal 10 with the help of the second sensor 11 detected.

At the following program point 105 it is checked whether there is a starting situation. If this is not the case, then becomes program point 100 Branched back. Will, however, at program point 105 Detected by the control unit that the speed of the vehicle is less than a comparison value, for example, 10 km / h and the clutch is actuated, there is a starting situation and it becomes the following program item 110 branched. At program point 110 controls the controller 6 the engine 2 in such a way that an additional torque for the starting assistance is provided in addition to the normal torque. Preferably, for the control of the engine 2 used a pilot value for the additional torque. The precontrol values are in the data memory 15 filed with the control unit 6 connected is. The basic operation of the clutch in terms of torque transmission between the engine 2 and the powertrain 4 is stored and used to set the additional torque required for starting assistance. The additional torque is stored, for example, in the form of maps or curves that are different parameters such. As the speed of the engine, the speed of the vehicle, the opening position of the clutch or the position of the clutch pedal or the speed of actuation of the clutch pedal or the speed of the closing operation of the clutch can depend.

In a further embodiment, the control device 6 when detecting a starting situation at program point 110 the engine 2 in such a way that the additional torque required for the starting assistance is kept ready in the form of a torque reserve before the additional torque is required. For this purpose, the throttle valve is opened and the ignition angle is delayed in the direction of a gasoline engine without significant change in the torque. Thus, by changing the ignition angle, a higher additional torque can be provided very quickly. The additional torque or the pre-control value for the additional torque or the provision of the additional torque reserve improves the starting assistance. In a further embodiment, the additional torque or the pre-control value for the additional torque for the starting assistance also depending on the driver's request, ie the accelerator pedal position can be set.

The additional torque depends, for example, on at least one of the following parameters: clutch position, ie open position or closed position of the clutch 3 , which is detected continuously or in stages, the position of the clutch pedal 10 , the speed of actuation of the clutch 3 , the speed of operation of the clutch pedal 10 , the driver's request, ie the position and / or the speed of the operation of the accelerator pedal 18 , the speed of the vehicle or the speed of the engine. For example, with a quick press of the accelerator pedal 18 or a driver's request for high torque, ie when a strong operation of the accelerator pedal 18 or a high speed of the engine, the need for an additional torque for the starting assistance lower than for a small driver's request or a small speed of the engine. In addition, with the aid of a weighting factor, the control unit 6 consider whether an idling control program is active or not.

The values of the additional torque or the pilot values of the additional torque can be defined by means of a starting value, a maximum value and an end of the starting assistance depending on the position of the clutch or the position of the clutch pedal. For example, the controller 6 the additional torque from the engine 2 then request if the gradient of the speed of the motor 2 becomes negative. The maximum value for the additional torque or the maximum pilot value for the additional torque can be set to the time when the negative speed gradient of the motor has the largest value. In addition, the pre-control value for the additional torque can be adapted to the word 0, for example, if the speed reaches the lowest value during the starting situation. If the speed increases again, then the pre-control value is equal to 0, so that the control unit 6 from the engine 2 no additional torque is required to support the starting situation of the vehicle. Depending on the chosen embodiment, other time points for starting, for specifying the maximum additional torque and / or for terminating the request for the additional torque from the engine 2 be determined.

The maximum additional torque or the maximum precontrol value for the additional torque to support the starting situation of the vehicle can be determined, for example, depending on the difference in the rotational speed of the engine before the starting situation and during the starting situation. For this purpose, for example, the difference in rotational speeds is detected and, depending on the difference, a weighting factor is determined which is multiplied by a constant torque value. However, there may be other functions and / or diagrams or tables are used to calculate the additional torque or the pilot value for the additional torque depending on the speed difference before the Anfahrsituation and during the starting situation. The greater the difference between the rotational speed before the starting situation and during the starting situation, the greater the need for additional torque to support the starting situation. For example, the additional torque or the pre-control value for the additional torque depending on the operating speed of the clutch pedal 10 be determined. There are corresponding tables or diagrams in the data memory 15 stored. Furthermore, for safety reasons, the maximum value for the additional torque or the maximum value for the pre-control value of the additional torque can be calculated or stored in the data memory 15 be filed. In addition, a maximum value for the temporal integral of the requested during a startup additional torque may be set to avoid a malfunction in the event of a malfunction of the engine.

The control unit 6 controls at program point 115 the engine 2 For example, the ignition, the throttle pump and / or the injection system of the engine 2 in such a way that the additional torque calculated for the starting assistance is provided or a corresponding torque reserve is kept ready.

In the following program point 120 checks the control unit 6 , whether fixed parameters of the engine 2 or the clutch 3 opposite in the data memory 15 have changed stored comparison values. If this is the case, at least one adaptation value is determined as a function of the change, which is taken into account in addition to the precontrol value for the additional torque or for the additional torque in future starting situations. The adaptation value can be stored in the form of a constant or in the form of functions depending on parameters of the internal combustion engine, the vehicle or the clutch. By using the at least one adaptation value, changes in the engine and / or changes to the clutch, which occur, for example, due to aging, are taken into account in determining the required additional torque for the starting assistance.

3 shows in a simple representation of a diagram for the value of the additional torque or the pilot value of the additional torque in dependence on the closed position or opening position of the clutch 3 , Starting from the open position of the clutch 3 the additional torque increases as the position of the clutch increases 3 in the direction of the closed position and falls to a maximum value up to the value 0 for the closed clutch 3 from. The closed clutch means that the clutch is the full torque of the engine 2 on the drive train 4 transfers. In the open position, no torque from the clutch 3 transfer.

4 shows a schematic representation of the diagram for the speed curve during a starting position in which the clutch is brought from the open to the closed state. Starting from the open position, the speed of the motor decreases 2 to a minimum value Wm and then rises again before the clutch has reached the closed position. The position of the clutch is detected in steps or continuously and used accordingly in the determination of the pilot value of the additional torque or the additional torque.

The additional torque desired for the starting assistance can be stored as a characteristic field as a function of a plurality of parameters, for example the open position of the clutch and the rotational speed of the internal combustion engine. The corresponding maps and characteristics for the desired additional torque for the starting assistance are in the data memory 15 stored.

After execution of the adaptation at program point 120 becomes program point 100 Branched back.

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 102006033025 A1 [0002]
• DE 10243143 B4 [0003]

Claims (13)

A method for starting assistance for a vehicle having a clutch which is arranged between an engine and a drive train, wherein a starting situation is detected and an additional torque is requested from the engine when detected starting situation, wherein a position of a clutch is detected, characterized in that depending on the position of the clutch between an open and closed position, a pilot value for the additional torque is determined and is used for a control of the engine. The method of claim 1, wherein the precontrol value is used to drive the motor to provide a torque reserve. Method according to one of claims 1 or 2, wherein the precontrol value is determined depending on the position of the clutch pedal. Method according to one of claims 1 to 3, wherein the precontrol value is determined depending on the rotational speed of the engine. Method according to one of claims 1 to 4, wherein an adaptation value for the pilot value is used, wherein the adaptation value is adjusted during operation of the motor vehicle. The method of claim 5, wherein the adaptation value is determined depending on a speed behavior of the engine when starting. Method according to one of claims 1 to 6, wherein the pilot value is adapted so that the precontrol value has a value greater than zero at a negative gradient of the engine speed and comes into effect. Method according to one of claims 1 to 7, wherein the pilot value is adapted so that the pilot value has a maximum value at a largest negative gradient of the engine speed. Method according to one of claims 1 to 8, wherein the pilot value is adapted so that the pilot value is returned to a value of zero when the engine speed has a minimum value and rises again. Method according to one of claims 1 to 9, wherein a maximum value for the pilot value is determined depending on a maximum difference in the engine speed before and during the starting situation. Method according to one of claims 1 to 10, wherein the precontrol value is determined depending on an operating speed of the clutch pedal. Method according to one of claims 1 to 11, wherein the pilot value is determined depending on an active or inactive idle speed controller. Method according to one of claims 1 to 12, wherein a maximum value for the pilot control value or a time integral over the pilot control value is provided during a starting process.

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