Method and control unit for operating a vehicle's powertrain

Abstract

Method for operating a vehicle's powertrain, wherein the drive train comprises a drive unit (1), an output (3) and an automated transmission (2) which is arranged in the drive train between the drive unit (1) and the output (3), wherein an input shaft (7) of the transmission (2) is connected to the drive unit (1) via a controllable disconnect clutch (6) and an output shaft (8) of the transmission (2) is connected to the output (3), wherein the transmission (2) has a main group (4), wherein, during a shutdown process of the drive unit (1), the main group (4) of the transmission (2) is moved into a neutral position and the neutral position is validated by means of a control-side predetermined, shutdown-process-side gate movement (14) of an actuating means of the main group (4) of the transmission (2), wherein a result of the plausibility check together with a target position of the shutdown-side lane movement (14) is stored in a control unit in a non-volatile memory of the same, wherein a subsequent start-up of the drive unit (1) can be carried out with the transmission (2) in neutral position, wherein, during the subsequent start-up process, when an ignition is activated, the result of the plausibility check of the neutral position and the target position of the shutdown-side lane movement (14) stored in the non-volatile memory are read out and the actual position of the actuating means is determined, the subsequent starting process of the drive unit (1) is then permitted if Data about a plausible neutral position can be read from the non-volatile memory, and Furthermore, the determined actual position of the actuating device corresponds to the stored target position.

Description

[0001] The invention relates to a method for operating a vehicle's powertrain. Furthermore, the invention relates to a control unit for operating a vehicle's powertrain.

[0002] Vehicles equipped with an automated transmission are parked in neutral. This is because, if a gear is engaged and the disconnect clutch (located between the transmission and the drive unit) is closed, the drive unit cannot be started. For example, in commercial vehicles, after extended periods of parking, it is not guaranteed that the pneumatic system will contain enough air to shift the transmission into neutral or disengage the disconnect clutch upon restart, as compressed air can leak from the vehicle's system. If the transmission is in neutral when the vehicle is parked, the drive unit is disengaged and can be started.

[0003] From DE 10 2012 213 253 A1, a drivetrain of a vehicle with an automated transmission, designed as a range transmission, is known. The range transmission has a main group and a range group connected downstream of the main group. The main group of the range transmission provides several gear ratios. From DE 10 2012 213 253 A1, it is known that the main group provides six gear ratios, namely four gear ratios for forward gears, one gear ratio for a so-called crawler gear, and one gear ratio for a reverse gear. The gear ratios of the main group can be selected via a gear shift pattern, which, according to DE 10 2012 213 253 A1, has two outer shift gates, a central shift gate arranged between the outer shift gates, and a selector gate connecting the shift gates.An actuating device can be moved to perform gear changes between the gear stages along the switching lanes and the selector lane.

[0004] Another powertrain of a vehicle with an automated transmission designed as a group transmission is known from DE 10 2016 224 243 A1. The group transmission known from this prior art has a main group, a range group downstream of the main group in terms of drive technology, and a pre-shift group upstream of the main group in terms of drive technology. The gear shift pattern of the main group has two outer shift gates and a selector gate connecting the outer shift gates, but no center shift gate.

[0005] From DE 10 2016 224 243 A1, it is known that a start-up of the drive unit is possible when the transmission is in neutral. When the drive unit is switched off, the automated transmission is moved to neutral, and the neutral position of the transmission is verified by means of a gate movement of an actuating element in the main group. The result of the verification is stored in a non-volatile memory of a control unit. During a subsequent start-up of the drive unit, the non-volatile memory is read. If data indicating that the neutral position of the transmission is plausible is read from the memory, the transmission is considered verified during the subsequent start-up of the drive unit without requiring another gate movement in the selector gate.

[0006] The invention is based on the objective of creating a method and control unit for operating a drive train, with which the safety during the starting process of the drive unit can be increased.

[0007] This problem is solved by a method for operating a vehicle drivetrain according to claim 1. According to the invention, during a shutdown process of the drive unit, the main assembly of the transmission is moved into a neutral position and the neutral position is validated by means of a control-side, shutdown-process-side gate movement of the actuating means of the main assembly of the transmission.

[0008] According to the invention, a result of the plausibility check, together with a target position of the shutdown-side lane movement or the actuating means, is stored in a non-volatile memory of a control unit.

[0009] A subsequent start of the drive unit can be performed with the transmission in neutral. During this start, when the ignition is activated, the result of the neutral position plausibility check and the target position of the gate movement or actuating element stored in the non-volatile memory are read, and the actual position of the actuating element is determined.

[0010] According to the invention, the subsequent start-up process of the drive unit is then permitted if data about a plausible neutral position is read from the non-volatile memory, and if, furthermore, the determined actual position of the actuating means corresponds to the stored target position of the actuating means.

[0011] The invention enhances safety during the start-up process of the drive unit. This is achieved by storing not only the result of the neutral position plausibility check but also the target position of the gate movement or actuating element during the shutdown process. If the drive unit is subsequently started by actuating the ignition, not only the result of the neutral position plausibility check but also the target position of the gate movement or actuating element is read. Furthermore, the actual position of the actuating element is determined. The subsequent start-up process is only permitted if data regarding a plausible neutral position is read and if the determined actual position of the actuating element corresponds to the stored target position of the actuating element.This allows verification that the data stored in the memory corresponds to the transmission's state before the ignition was switched on, i.e., whether it originates from the last shutdown of the drive unit. Ultimately, this can increase safety when subsequently starting the drive unit.

[0012] Preferably, during the shutdown process of the drive unit, the actuating element is moved to a target position by the control-specified, shutdown-process-related gate movement. This target position differs from the target position that would be reached if the transmission were moved to neutral without a shutdown process of the drive unit. This further increases safety during a start-up process of the drive unit. It ensures that read-out data originates from a previous shutdown process of the drive unit or was stored in memory during a previous shutdown process.

[0013] According to an advantageous embodiment of the invention, during the shutdown process of the drive unit, the pre-control group and / or the area group is moved to a target position specified by the control system, wherein the target position of the pre-control group and / or the area group is stored in the non-volatile memory. During the subsequent start-up process, the target position of the pre-control group and / or the area group is read from the non-volatile memory, and the actual position of the pre-control group and / or the area group is determined. The subsequent start-up process is then permitted if the determined actual position of the pre-control group and / or the area group corresponds to the respective stored target position.Preferably, during the shutdown process of the drive unit, the pre-selector group and / or range group is moved to a target position that differs from the target position of a transmission moving to neutral without a shutdown process of the drive unit. These features also serve to further increase the safety of a drive unit start-up. Furthermore, if a target position of a pre-selector group and / or a target position of a range group is also stored during a shutdown process, and the subsequent start-up is permitted only if the actual position of the pre-selector group and / or range group determined during the start-up corresponds to the read and stored target position, a further increase in safety for the subsequent start-up is possible.

[0014] Following a beneficial further development, the target position of the actuating device and / or the target position of the pre-control group and / or the target position of the control group is changed from one shutdown operation to the next for the drive unit. This also serves to increase the safety of a drive unit, namely to ensure that data read from the memory actually reflects the state at the time of the last shutdown of the drive unit.

[0015] The control unit according to the invention is defined in claim 6.

[0016] Preferred embodiments are described in the dependent claims and the following description. Exemplary embodiments of the invention are explained in more detail with reference to the drawing, without being limited thereto. The drawing shows: Fig. 1 a diagram of a vehicle's powertrain; Fig. 2 a gear shift diagram of a main group of a vehicle transmission with a gate movement.

[0017] Fig. Figure 1 shows a powertrain diagram of a vehicle's powertrain. The powertrain of the Fig. 1 has a drive unit 1 and a gearbox 2, wherein the gearbox 2 is positioned between the drive unit 1 and an output 3.

[0018] Gearbox 2 is an automated gearbox designed as a group gearbox.

[0019] In the exemplary embodiment of the Fig. 1 The group transmission comprises a main group 4 and preferably a drive-technically downstream area group 5 of the main group 4.

[0020] Additionally, the group transmission 2 can also have a pre-shift group upstream of the main group 4 in terms of drive technology. The pre-shift group can also be present instead of the range group 5.

[0021] An input shaft 7 of the gearbox 2 is connected to the drive unit 1 via a controllable disconnect clutch 6.

[0022] An output shaft 8 of the gearbox 2 is connected to the output shaft 3.

[0023] Main group 4 of gearbox 2 has several gear ratio stages. In the Fig. In the embodiment shown in Figure 1, the main group 4 provides four transmission stages 1, 2, 3, and 4 for four forward gears, one transmission stage R for a reverse gear, and one transmission stage C for a so-called crawler gear. The range group 5 provides a low-speed stage L and a high-speed stage S.

[0024] The transmission stages of the main group 4 can be switched via a gear shift diagram 9 with, in the illustrated embodiment, three shift lanes 10, 11, 12 and a selector lane 13 connecting the shift lanes 10, 11 and 12, by means that an actuating means can be moved along the shift lanes 10, 11 and 12 and the selector lane 13.

[0025] Then, when a neutral position of the transmission 2 is requested by the driver with the ignition switched on, or when a neutral position of the transmission 2 is requested by the control system as a result of the ignition being switched off during a shutdown process of the drive unit 1, the neutral position is validated by means of a gate movement of the actuating element of the main group 4 of the transmission 2.

[0026] The result of the plausibility check is stored in a non-volatile memory of a control unit in order to allow or disallow a subsequent start process of the drive unit 1, depending on this.

[0027] The invention now relates to details by means of which a starting process of the drive unit 1 can be made particularly safe.

[0028] In accordance with the present invention, during a shutdown process of the drive unit 1, the transmission 2 is moved into a neutral position, namely the main group 4 of the transmission 2. The neutral position of the main group 4 of the transmission 2 is validated by means of a control-side predetermined, shutdown-process-side gate movement 14 of an actuating means of the main group 4 of the transmission 2.

[0029] In this process, not only is a result of this plausibility check stored in a control unit, namely in the non-volatile memory of the control unit, but also a target position of the actuating means of the main group 4 is stored during the shutdown process-side lane movement 14, which is carried out to check the plausibility of the neutral position.

[0030] Fig. Figure 2 shows an example of such a shutdown-process-side lane movement 14, wherein in Fig. 2. Before the execution of the gate movement 14, the actuating element is located in the upper area of ​​the shift gate 11. To move the transmission 2 into the neutral position and to further verify the neutral position, the gate movement 14 is executed, and the actuating element is moved from the shift gate 11 along the selector gate 13 into the area of ​​the shift gate 10.

[0031] Then, when such a lane movement is successfully executed, the result of the successful execution of the lane movement 14 is stored in the non-volatile memory of the control unit, together with the target position of the actuating means during this lane movement 14.

[0032] During a subsequent start-up process, when the vehicle's ignition is switched on, the result of the neutral position plausibility check stored in the control unit's non-volatile memory, as well as the target position of the actuator during the gate movement 14 on the shutdown side, are read out. Furthermore, when the ignition is switched on, the actual position of the actuator in the gear shift diagram 9 is determined.

[0033] The subsequent start-up of the drive unit 1 is permitted if data regarding a plausible neutral position is read from the non-volatile memory, and if the determined actual position of the actuator corresponds to the stored target position. This allows the conclusion that the read data originates from a plausibility check of the neutral position, which was determined during a previous shutdown. This increases the safety of starting the drive unit.

[0034] Preferably, it is provided that during the shutdown process of the drive unit 1, the actuating means is moved by the control-side, shutdown-process-side gate movement 14 into a target position that differs from the target position of a transition of the transmission 2 to the neutral position not triggered by a shutdown process of the drive unit 1. Thus, if the transmission 2 is moved to a neutral position, for example by the driver, while the drive unit 1 is running and therefore not switched off, the actuating means then assumes a different position than the position to which the actuating means is moved by a shutdown-process-side gate movement. Fig. In the embodiment shown in Figure 2, such a target position of a shutdown-side lane movement 14 is a target position in the shift lane 10 for the reverse gear R and the crawler gear C.

[0035] According to an advantageous embodiment of the invention, it is further provided that, during a shutdown process of the drive unit 1, the area group 5 and / or any preceding group that may be present is transferred to a target position specified by the control system. This target position of area group 5 and / or the preceding group that may be present is then stored in the non-volatile memory.

[0036] During a subsequent start-up process, not only is the target position of the actuator of main group 4 read from the memory, but also the target position of area group 5 and / or any existing pre-group. Furthermore, the actual position of area group 5 and / or any existing pre-group is determined.

[0037] A subsequent start of the drive unit 1 is permitted if data on a plausible neutral position is read from the non-volatile memory, if the determined actual position of the actuator corresponds to the stored target position, and if, furthermore, the determined actual position of area group 5 and / or any existing pre-control group corresponds to the respective stored target position. This further increases safety when starting the drive unit 1.

[0038] During the transition of the pre-selector group and / or the range group 5 to a target position specified by the control system during the shutdown process, it is preferably provided that during the shutdown process of the drive unit 1, the pre-selector group and / or the range group is transitioned to a target position that differs from the target position of a transition of the transmission 2 to the neutral position not triggered by a shutdown process of the drive unit.

[0039] In the illustrated embodiment, it can be provided that, in addition to the gate movement 14 for the actuating element of the main group 4 into the shift gate 10, the range group 5 is transferred to the high-speed gear S during a shutdown operation of the drive unit 1 and during a shutdown operation-side transfer of the transmission 2 to the neutral position. These target positions for the actuating element of the main transmission 4 and for the range group 5 differ from the target positions to which they are transferred during a transfer operation of the transmission 2 to the neutral position not triggered by a shutdown operation of the drive unit 1.

[0040] In particular, the combination of the target position of the actuating means of main group 4 in combination with the target position of range group 5 is atypical, since a reverse gear R and a crawler gear C are typically only engaged in main group 4 when range group 5 is in the slow speed stage.

[0041] Therefore, if, during a shutdown of the drive unit 1, the actuating element of the main transmission 4 is moved into shift gate 10 for reverse gear R and crawler gear C, and the range group 5 is moved to a target position for a high-speed gear S, these target positions are stored. If, during a subsequent start-up, it is determined that the actual positions of the actuating element of main group 4 and range group 5 correspond to the stored target positions, then, in combination with data read out regarding a plausible neutral position, the subsequent start-up of the drive unit 1 can be approved with a high degree of certainty, since it can be concluded that the data read out was indeed determined during a previous shutdown of the drive unit 1.

[0042] To further enhance safety, it may be possible to change the target position of the actuator of main group 4 and / or the target position of the pre-selector group and / or the target position of the range group 5 from one shutdown to the next of the drive unit 1's shutdowns. This ensures that new target positions are stored with each shutdown of drive unit 1 and with each plausibility check of the neutral position. This further increases the safety of starting drive unit 1 during subsequent startup processes, ensuring that data read out regarding a plausible neutral position of transmission 2 actually originates from an immediately preceding shutdown of drive unit 1 and a corresponding movement of the actuator of main group 4 of transmission 2.

[0043] The invention further relates to a control unit for carrying out the method according to the invention, wherein the control unit is a transmission control unit.

[0044] During a shutdown process of the drive unit 1, the control unit transfers the main group 4 of the transmission 2 to a neutral position and verifies this neutral position by means of a control-side specified, shutdown-side gate movement 14 of the actuating means in the gear shift diagram 9 of the main group 4 of the transmission 2.

[0045] The result of this plausibility check, i.e., the successful or unsuccessful execution of the gate movement, is stored in the control unit's memory along with a target position of the actuator during the gate movement. During a subsequent start-up process, when the ignition is switched on, the control unit reads the stored result of the neutral position plausibility check and the target position of the actuator during the gate movement 14 (on the shutdown side) from the memory and determines the actual position of the actuator of main group 4 of the transmission 2, for example, by reading data from a sensor that determines the position of the actuator in the gear shift diagram 9.The control unit allows the subsequent start process of the drive unit 1 if the control unit reads data about a plausible neutral position from its non-volatile memory, and if the control unit further determines that the determined actual position of the actuating device corresponds to the stored and read target position.

[0046] The control unit executes the method described above and has both hardware and software means for this purpose. The hardware means include data interfaces for exchanging data with the assemblies involved in carrying out the method according to the invention. Furthermore, the hardware means include a processor for data processing and memory for data storage. The software means include program modules for carrying out the method according to the invention. Reference sign 1 drive unit 2 gearboxes 3 Drive 4 Main Group 5 Area Group 6 Disconnect coupling 7 Input wave 8 Output wave 9 Gear shift diagram 10 shift gate 11 Shift lane 12 shift gate 13 Wählgasse 14 alleyway movement

Claims

[1] Method for operating a vehicle powertrain, wherein the drive train comprises a drive unit (1), an output (3) and an automated transmission (2) which is arranged in the drive train between the drive unit (1) and the output (3), wherein an input shaft (7) of the transmission (2) is connected to the drive unit (1) via a controllable disconnect clutch (6) and an output shaft (8) of the transmission (2) is connected to the output (3), wherein the transmission (2) has a main group (4), wherein, during a shutdown process of the drive unit (1), the main group (4) of the transmission (2) is moved into a neutral position and the neutral position is validated by means of a control-side predetermined, shutdown-process-side gate movement (14) of an actuating means of the main group (4) of the transmission (2), wherein a result of the plausibility check together with a target position of the shutdown-side lane movement (14) is stored in a control unit in a non-volatile memory of the same, wherein a subsequent start-up of the drive unit (1) can be carried out with the transmission (2) in neutral position, wherein, during the subsequent start-up process, when an ignition is activated, the result of the plausibility check of the neutral position and the target position of the shutdown-side lane movement (14) stored in the non-volatile memory are read out and the actual position of the actuating means is determined, the subsequent starting process of the drive unit (1) is then permitted if Data about a plausible neutral position can be read from the non-volatile memory, and Furthermore, the determined actual position of the actuating device corresponds to the stored target position. [2] Method according to claim 1, characterized by , that the transmission (2) has a group transmission with the main group (4) as well as • with one of the main group (4) upstream of the drive-related upstream group and / or • with a subgroup (5) following the main group (4). [3] Method according to claim 2, characterized by , that during the shutdown process of the drive unit (1) the pre-group and / or the area group (5) is transferred to a target position specified by the control system, and the target position of the pre-group and / or the area group (5) is stored in the non-volatile memory during the subsequent start process the target position of the pre-group and / or the area group (5) is read from the non-volatile memory and the actual position of the pre-group and / or the area group (5) is determined, and The subsequent start process is then permitted if the determined actual position of the upstream group and / or the area group (5) corresponds to the respective stored target position. [4] Method according to claim 2 or 3, characterized by , that during the shutdown process of the drive unit (1) the pre-selector group and / or range group (5) is transferred to a target position which differs from a target position when the transmission (2) is transferred to neutral without being triggered by a shutdown process of the drive unit (1). [5] Method according to any one of claims 2 to 4, characterized by, that the target position of the actuating means and / or the target position of the pre-group and / or the target position of the area group (5) is changed from shutdown operation to shutdown operation of the drive unit (1). [6] Method according to any one of claims 1 to 5, characterized by , that during the shutdown process of the drive unit (1) the actuating means of the main group (4) is transferred to a target position by the control-side specified, shutdown-side gate movement (14) which differs from a target position when the transmission (2) is transferred to the neutral position not triggered by a shutdown process of the drive unit (1). [7] Control unit for operating a transmission (2) of a vehicle, wherein the control unit is designed such that, during a shutdown process of a drive unit (1) of the vehicle, it transfers a main group (4) of the transmission (2) into a neutral position and verifies the neutral position by means of a control-side predetermined, shutdown-process-side gate movement (14) of an actuating means of the main group (4) of the transmission (2), wherein the control unit stores a result of the plausibility check together with a target position of the shutdown-side lane movement (14) in a non-volatile memory of the same. wherein, during the subsequent start-up process, when the ignition is activated, the control unit reads the result of the plausibility check of the neutral position and the target position of the shutdown-side gate movement (14) stored in the non-volatile memory and determines the actual position of the actuating means, the control unit then allows the subsequent start process if reads the same data about a plausible neutral position from the non-volatile memory, and furthermore, it finds that the determined actual position of the actuating device corresponds to the stored target position. [8] Control unit for operating the transmission (2) according to claim 7, characterized by , that the transmission (2) has a group transmission with the main group (4) as well as • with one of the main group (4) upstream of the drive-related upstream group and / or • with a subgroup (5) following the main group (4). [9] Control unit according to claim 8, characterized by , that the control unit is designed in such a way that during the shutdown process of the drive unit (1) the pre-group and / or the area group (5) is transferred to a target position specified by the control system, and the target position of the pre-group and / or the area group (5) is stored in the non-volatile memory, which the control unit uses during the subsequent start process reads the target position of the pre-group and / or the area group (5) from the non-volatile memory and determines the actual position of the pre-group and / or the area group (5), and the subsequent start process is then permitted if the determined actual position of the upstream group and / or the area group (5) corresponds to the respective stored target position. [10] Control unit according to claim 8 or 9, characterized by , that it is designed in such a way that, during the shutdown process of the drive unit (1), it transfers the pre-selector group and / or range group (5) to a target position which differs from a target position when the transmission (2) is transferred to neutral without being triggered by a shutdown process of the drive unit (1). [11] Control unit according to one of claims 8 to 10, characterized by , that it is designed in such a way that it changes the target position of the actuating means and / or the target position of the pre-group and / or the target position of the area group (5) from shutdown operation to shutdown operation of the drive unit (1). [12] Control unit according to any one of claims 7 to 11, characterized by , that it is designed in such a way that, during the shutdown process of the drive unit (1), it transfers the actuating means to a target position by means of the control-side specified, shutdown-side gate movement (14), which differs from a target position when the transmission (2) is transferred to the neutral position without being triggered by a shutdown process of the drive unit (1).

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