DE102017203782B3 - Method and control device for operating a motor vehicle - Google Patents

Abstract

Method for operating a motor vehicle with a drive unit (1), a transmission (2) having a plurality of shift elements (9, 10, 11, 12, 13) and an output (14), wherein the transmission (2) is an automatic or automated transmission formed and between the drive unit (1) and the output (14) is connected, wherein in each positive gear a first number of switching elements closed and a second number of switching elements is opened, depending on at least one operating condition entered into a sailing mode and subsequently dependent is withdrawn from the sailing mode of at least one operating condition, starting to enter the sailing mode starting from a non-positive gear, a switching element is driven to open, so that a switching element less closed and thus a switching element is more open than in a non-positive gear, in sail mode the each closed and opened Scha be tracked depending on at least one operating condition. Then, after entering the sailing mode, if the transmission input speed has reached or fallen below a first threshold, but is greater than a second threshold, it is monitored whether the transmission input speed increases above a third threshold during sailing mode, and then, if determined, this the case is closed on a faulty behavior of a switching element. ()

Description

The invention relates to a method for operating a motor vehicle. Furthermore, the invention relates to a control device for carrying out the method.

From the DE 10 2011 005 320 A1 a method for operating a motor vehicle is known, which comprises a drive unit, a transmission and an output, wherein the transmission is connected between the drive unit and the output. The transmission is an automatic or automated manual transmission. After DE 10 2011 005 320 A1 Depending on at least one operating condition of the motor vehicle, a sailing mode for the motor vehicle is activated or entered into it and subsequently the sailing mode is deactivated or exited therefrom depending on at least one operating condition of the motor vehicle. While the motor vehicle is running with the internal combustion engine coupled to the output, the sailing mode is activated when a driver request torque dependent on an accelerator operation or a driver torque predetermined driving torque is within a defined range for a defined time and if the current acceleration or deceleration continues of the motor vehicle is within a defined range.

From the DE 10 2010 000 857 A1 Another method for operating a motor vehicle is known. Thus, on the one hand details of a shift sequence for a gear layout for entry into a sailing operation and the other details of a shift sequence for a gear engagement to exit from the sailing operation are disclosed.

Also the DE 10 2014 219 598 A1 discloses a method for operating a motor vehicle, namely details for terminating the mode of operation sailing and, thus, details for exiting a sailing operation. After that, to set the operating mode sailing for the transmission, a target gear and a speed control for the drive unit is specified. During the speed control, it is monitored which switching elements of the transmission are to be considered closed, wherein when a defined number of switching elements is to be considered closed, a monitoring function is triggered.

It is known from the prior art that when entering a sailing mode, in the sailing mode of the motor vehicle, the respectively closed and open shifting elements of the transmission, depending on at least one operating condition of the motor vehicle, nachzuführen or change. This serves to ensure that when it is to be stepped out of the sailing mode, as quickly and conveniently as a suitable non-positive gear in the transmission can be inserted. Then, when the respective closed or open switching elements are tracked in sail mode, therefore, takes place during the sailing mode, a change from an actual sail passage to a target sail passage, wherein in each league a switching element is open more than in a non-positive gear. To exit from the sailing mode, only a further switching element of the transmission has to be closed, starting from the current actual sail passage, in order to engage in a non-positive gear in the transmission.

In particular, in the tracking of the leap or the tracking of the sailing mode in each case closed and open switching elements may be due to defects in the control valves of the switching elements or as a result of Fehlansteuerungen the switching elements that an openable switching element can not be opened. In this case, then an unwanted adhesion in the transmission can form during the sailing mode, which leads to an unwanted delay and thus to a noticeable loss of comfort. This is a disadvantage. There is a need for a method by which the behavior of the switching elements can be monitored during sailing mode.

On this basis, the invention is based on the object to provide a novel method for operating a motor vehicle and a control device for operating a motor vehicle.

This object is achieved by a method for operating a motor vehicle according to claim 1.

According to the invention, when after entering the sailing mode, the transmission input speed has reached or fallen below a first threshold, but is greater than a second threshold, monitors whether increases during transmission mode, the transmission input speed above a third threshold. Then, when it is determined that the transmission input speed increases above the third threshold during the sailing mode, an erroneous behavior of a switching element in the sailing mode is inferred. With the invention immediately after the entry into the sailing mode after the transmission input speed has fallen below the first threshold but still greater than the second threshold, monitors whether the transmission input speed increases in sailing mode above a third threshold. This can reliably after the entry into the sailing mode, while the transmission input speed is still falling, the behavior the switching elements are checked in sailing mode.

According to a development of the invention, the third limit value is continuously recalculated. At fixed sail, the third limit is calculated depending on the output speed and a translation of the fixed sail. Then, when downshifting or upshifting from an actual sail passage to a target sail passage, the third threshold is calculated depending on the output speed and a gear ratio of the target sail passage. The third limit can be optimally adapted to check the behavior of the switching elements of the transmission immediately after the entry into the sailing mode while still falling in gearbox input speed.

According to a further development, a switchback without a time delay switches to the newly calculated third limit value. In an upshift is changed with a time delay to the newly calculated third limit, the time delay is preferably dependent on the jump in gear upshift. These features are used to reliably check the behavior of the switching elements of a transmission immediately after entering the sailing mode, so while the transmission input speed is still falling.

According to a development of the invention, then, when sailing with laufendendem drive unit, the second limit of an idle speed of the drive unit or a defined offset value is greater than idle speed, whereas when it is sailed with stopped drive unit, the second limit equal to zero or a defined offset value is greater than zero.

The control device according to the invention is defined in claim 10.

• 1 ein Antriebstrangschema eines Kraftfahrzeugs mit einem Getriebe; und
• 2 eine Schaltmatrix des Getriebes der 1.

Preferred developments emerge from the subclaims and the following description. Embodiments of the invention will be described, without being limited thereto, with reference to the drawings. Showing:

• 1 a powertrain diagram of a motor vehicle with a transmission; and
• 2 a switching matrix of the transmission of 1 ,

The invention relates to a method and a control device for operating a motor vehicle and a control device for carrying out the method.

1 shows very schematically a drive train scheme of a motor vehicle with an automatic transmission 2 , The powertrain of 1 includes a drive unit 1 , the automatic transmission 2 and a downforce 14 , where the automatic transmission 2 between the drive unit 1 and the downforce 14 is switched.

The automatic transmission 2 has several wheelsets 3 . 4 . 5 and 6 as well as several switching elements interacting with these wheelsets 9 . 10 . 11 . 12 and 13, wherein the two switching elements 9 and 10 Also referred to as switching elements A and B, and wherein the switching elements 11 . 12 and 13 Also referred to as switching elements C, D and E. In the switching elements A and B and the switching elements C, D and E are each frictional switching elements, namely in the switching elements A and B to brakes and the switching elements C, D and E to clutches.

2 shows a switching matrix of the automatic transmission 2 of the 1 , 2 can be seen that with the gearbox 2 of the 1 a total of eight forward gears and one reverse gear can be provided. In each of these traction-transmitting gears, a first number of shifting elements, namely three shifting elements, are closed, whereas a second number of shifting elements, namely two shifting elements, are respectively opened in each traction-transmitting gear. The shift elements, which are closed in the respective traction-transmitting gear are in 2 marked by a dot. So are in forward gear 1 the switching elements A, B and C and in forward gear 2 the switching elements A, B and E closed. In reverse, the switching elements A, B and D are closed. The in the forward gears 3 . 4 . 5 . 6 . 7 and 8th closed switching elements also follow from the switching matrix of 2 ,

1 shows that the drive unit 1 to a transmission input shaft 7 and the downforce 14 to a transmission output shaft 8th is coupled. Depending on the gearbox 2 engaged gear converts the transmission 2 Speeds and torques and thus provides the traction power supply of the drive unit 1 at the output 14 ready.

Between the drive unit 1 and the transmission input shaft 7 In particular, a converter is connected in 1 not shown. Such a converter has a turbine, the turbine being connected to the transmission input shaft 7 is coupled. Furthermore, a converter has a pump, a freewheel and a lockup clutch. The structure of such a converter is familiar to the person skilled in the art.

Instead of a converter can also be a starting clutch between the drive unit 1 and the transmission input shaft 7 be switched.

It should be noted that in 1 shown gearbox 2 which the in 2 used switching matrix is exemplary nature. The invention can also be used in motor vehicles with other transmission configurations.

Like the switching matrix of 2 can be removed is in each zugkraftübertragenden or non-positive gear of the transmission 2 a first defined number of switching elements 9 to 10 closed or switched on and a second defined number of switching elements 9 to 13 opened or switched off. 2 it can be seen that in each non-positive gear three switching elements are closed and two switching elements are open.

It is already known that then, in the transmission 2 of the motor vehicle, a non-positive gear is engaged and the motor vehicle travels in this non-positive gear, depending on at least one operating condition of the motor vehicle is entered in a sailing mode, for entering into the sailing mode of the motor vehicle, starting from an inserted, non-positive gear, a switching element of the transmission 2 , which is closed in non-positive gear, is controlled to open, so that in sailing mode, a switching element of the transmission 2 less closed and thus a switching element of the transmission 2 is more open than in an inserted, non-positive gear, so then the traction in the transmission 2 is interrupted. When sailing, the drive unit 1 run or alternatively be shut down. The shift elements of the transmission 2 that are closed in sail mode, so to speak, form a non-positive sail passage.

Furthermore, it is already known, after the entry into a sailing mode below depending on at least one operating condition of the motor vehicle from the sailing mode again auszuschteigen. For this purpose, starting from the sailing mode, a switching element is closed to engage a non-positive gear.

Furthermore, it is already known that in the sailing mode of the motor vehicle, the respectively closed and opened switching elements of the transmission 2 be tracked or changed depending on at least one operating condition of the motor vehicle. As a result, the non-positive sailing course is tracked in sailing mode. This tracking of the sails allows a spontaneous and comfortable exit from the sailing mode.

As already stated above, in every non-positive gear of the transmission 2 a first number of the switching elements 9 to 13 closed and a second number of switching elements 9 to 13 open. Then, when the sailing mode of the motor vehicle is active, in sailing mode is a switching element of the transmission 2 more open than in a non-positive gear. The respective closed in sail mode switching elements define the so-called non-positive sailing gear, can be changed from the starting, by closing a further switching element in a non-positive gear to exit the sailing mode.

The present invention relates to a method by means of which, immediately after an entry into the sailing mode, and while the transmission input speed is understood after the entry into the sailing mode in the fall, the function of the switching elements of the transmission 2 can be checked, especially if in this state of the sailing mode, the respective closed and opened switching elements of the transmission 1 be tracked or changed to change the respective sailing course.

According to the invention, when, after entering the sailing mode, the transmission input speed has dropped below a first limit value but is still greater than a second limit value, it is monitored whether the transmission input speed rises above a third limit value during the sailing mode. Then, when it is determined that during the sailing mode the transmission input speed, which is decreasing from the first limit value towards the second limit value, rises above the third limit value, an erroneous behavior of a shifting element in the transmission is inferred, in particular a faulty one Behavior of an openable switching element.

First, therefore, it is checked whether after entering the sailing mode, the transmission input speed has fallen below the first limit, the first limit of the speed at the output 14 of the motor vehicle as well as the translation of auszulegenden at entry into the sailing mode, non-positive gear is dependent.

For example, if a difference between the current, measured transmission input speed and this depending on the output speed and the translation of the starting in the sailing mode, frictional gear dependent speed greater than a threshold, it is concluded that after entering the sailing mode, the transmission input speed below the first limit has fallen and that for the Designing the non-positive gear to open the switching element could be successfully opened.

At this time, ie immediately after entering the sailing mode, the transmission input speed is greater than the second limit, the second limit, if with the drive unit running 1 is sailed, the idle speed of the drive unit 1 corresponds or a defined offset is greater than the idling speed, whereas, if with the drive unit stopped 1 is sailed, the second limit is zero or a defined offset is greater than zero.

Then, when, after entering the sailing mode, when the transmission input speed has dropped below the first threshold, but is still greater than the second threshold, and is therefore decreasing from the first threshold towards the second threshold, it is monitored whether the measured Transmission input speed increases during sailing mode above the third threshold. This third limit is continuously recalculated and tracked.

Then, if the current sail gear does not change, ie if it is sailed in a fixed sail course, the third limit, depending on the output speed at the output 14 and calculated depending on the translation of the fixed sail, the translation of the fixed sail gear corresponds to that translation, which would be provided if starting from this leap gear by closing a further switching element, a non-positive gear would be engaged. The third limit is then dependent on the product of the current output speed and the translation of the current, fixed sail course preferably offset with a speed offset.

Then, after entering the sailing mode while the transmission input speed is still falling from the first limit toward the second limit, an upshift or downshift from an actual sail into a target sail is made, the third threshold depending on the output speed of the output 14 and a gear ratio of the target sailing gear is calculated, wherein the gear ratio of the target sailing gear corresponds to that gear ratio that is provided when entering from the target sailing gear by closing another switching element in a non-positive gear of the transmission. In both cases, then the third limit of the product of the output speed of the output 14 and the translation of the target sailing gear depending, preferably each offset with a speed offset.

In the above three cases, that is, sailing with a firm sail, sailing with a downshift from an actual sail into a target sail, and sailing with a shift from an actual sail to a target, the third limit is preferably each depends on a speed offset, wherein for all three cases preferably an individual speed offset is used.

Then, when immediately after the entry into the sailing mode at falling falling transmission input speed a Segelgangnachführung in the sense of a downshift from an actual Sailing gear to a smaller target Sailing gear is changed immediately without delay to the newly calculated third limit.

On the other hand, if in the sailing mode, when the transmission input speed is falling, an upshift from an actual sail gear to a higher target sail gear is performed, the timing changes to the newly calculated third threshold. This time delay is dependent in particular on the transition of the course of the sail passage between the actual sail course and the target sail course of the respective upshift.

As already stated, when it is determined during execution of the method according to the invention that during the sailing mode the transmission input speed rises above the respective valid, third threshold value, an erroneous behavior of a switching element is concluded, in particular an erroneous behavior of the actual gear tracking of the sail passage opening switching element.

The invention further relates to a control device for carrying out the method, wherein the control device is preferably an electronic transmission control unit. The controller monitors when, after entering the sailing mode, the transmission input speed has dropped below the first threshold but still greater than the second threshold, the transmission input speed rises above a third threshold during sailing mode, and then, if the controller determines that that in the sailing mode, the transmission input speed increases above the third threshold, on a faulty behavior of a switching element of the transmission in sailing mode closes.

The control device comprises means for carrying out the method, namely hardware-side means and software-side means. The hardware resources include data interfaces for exchanging data with the components involved in the execution of the method according to the invention, for example with control valves of the switching elements and a speed sensor which serves to metrologically detect the transmission input rotational speed. Furthermore, the transmission control unit comprises, as a hardware-side means, a memory for data storage and a processor for data processing. As a software-side means, the control unit comprises program modules for carrying out the method according to the invention.

LIST OF REFERENCE NUMBERS

1

power unit

2

automatic transmission

3

wheelset

4

wheelset

5

wheelset

6

wheelset

7

Transmission input shaft

8th

Transmission output shaft

9

Switching element A

10

Switching element B

11

Switching element C

12

Switching element D

13

Switching element E

14

output

Claims (11)

Method for operating a motor vehicle with a drive unit (1), a transmission (2) having a plurality of shift elements (9, 10, 11, 12, 13) and an output (14), wherein the transmission (2) is designed as an automatic or automated transmission and between the drive unit (1) and the output (14) is connected, wherein in each inserted, non-positive gear of the transmission (2), a first number of switching elements (9, 10, 11, 12, 13) of the transmission (2) closed or switched on and a second number of switching elements (9, 10, 11, 12, 13) of the transmission (2) is opened or disconnected, wherein depending on at least one operating condition of the motor vehicle is entered in a sailing mode, hereinafter depending on at least one operating condition of the motor vehicle is released from the sailing mode, wherein for entering into the sailing mode of the motor vehicle starting from a non-positive gear, a switching element of the transmission (2 ) is opened to open, so that a switching element less closed and thus a switching element is more open than in an inserted, non-positive gear, wherein in the sailing mode of the motor vehicle each closed and opened switching elements of the transmission (2) tracked depending on at least one operating condition of the motor vehicle or be changed, characterized in that when after entering the sailing mode, the transmission input speed has reached or fallen below a first threshold, but is greater than a second threshold is monitored, whether during the sailing mode in particular when tracking the switching elements, the transmission input speed above of a third threshold, then, when it is determined that the transmission input speed is increasing above the third threshold during the sailing mode, an erroneous behavior of a switching element in the sailing mode is inferred. Method according to Claim 1 , characterized in that, when it is determined that the transmission input speed rises above the third threshold during the sailing mode, an erroneous behavior of an opening switching element is concluded. Method according to one of Claims 1 or 2 , characterized in that the third limit value is continuously recalculated. Method according to one of Claims 1 to 3 , characterized in that at fixed sail the third limit is calculated depending on the output speed and a translation of the fixed sail. Method according to one of Claims 1 to 4 Characterized in that, when a downshift of an actual sailing gear, the third limit value is calculated depending on the output speed and a ratio of the target gear is carried sail in a sailing target gear. Method according to Claim 5 , characterized in that is switched at a downshift from the actual sail gear in the target sailing course without delay to the newly calculated third limit. Method according to one of Claims 1 to 6 Characterized in that, when an upshift from an actual sailing gear, the third limit value is calculated depending on the output speed and a ratio of the target gear is carried sail in a sailing target gear. Method according to Claim 7 , characterized in that at an upshift of the actual Sail gear is changed in the target sail with a time delay to the newly calculated third limit, the time delay is preferably dependent on the transition between the actual Sailing gear and the target Sailing gear of the upshift. Method according to one of Claims 1 to 8th characterized in that, when sailing with the drive unit running, the second limit value corresponds to an idle speed of the prime mover or a defined offset value is greater than idle speed, whereas when sailing with the prime mover stopped, the second limit value equals zero or a defined offset value is greater than zero. Control unit for operating a motor vehicle with a drive unit (1), a plurality of shift elements (9, 10, 11, 12, 13) having transmission (2) and an output (14), wherein the transmission (2) designed as an automatic or automated transmission and between the drive unit (1) and the output (14) is connected, wherein the control unit in each inserted, non-positive gear of the transmission (2) a first number of switching elements (9, 10, 11, 12, 13) of the transmission (2 ) for closing and a second number of the switching elements (9, 10, 11, 12, 13) of the transmission (2) for opening controls, depending on at least one operating condition of the motor vehicle, the transmission for entering a sailing mode controls, hereinafter depending on at least one Operating condition of the motor vehicle drives the gearbox to get out of the sailing mode, for entering into the sailing mode of the motor vehicle, starting from a non-positive gear a switching element the transmission (2) controls to open, so that a switching element less closed and thus a switching element is more open than in an engaged, non-positive gear, in the sailing mode of the motor vehicle, the control of each closed and open switching elements of the transmission (2) depending on at least one Operating condition of the motor vehicle nachzuführen or changes, characterized in that the control unit, if after entering the sailing mode, the transmission input speed has reached or fallen below a first threshold, but is greater than a second threshold, monitors whether during the sailing mode in particular when tracking the Switching the transmission input speed increases above a third threshold, the controller then, if the same determines that during the sailing mode, the transmission input speed increases above the third threshold, on a faulty behavior of a switching element in Segelmod us closes. Control unit after Claim 10 , characterized in that the same means for carrying out the method according to one of Claims 1 to 9 having.

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