Method for learning and storing operating data in a drive train of a motor vehicle

Abstract

Method for operating a drive train of a motor vehicle containing an automated transmission with at least one friction clutch, with a control unit for controlling the transmission on the basis of learned and / or adapted operating data, in which the control unit is provided with a monitoring system, which is activated when the control unit is activated, to avoid safety-relevant operating states of the transmission during driving of the motor vehicle, and during a learning phase carried out by means of a test device having a signal connection to the control unit, with the monitoring system deactivated, operating data of the drive train are learned and stored in a volatile working memory,wherein, in a follow-up phase during a shutdown of the control unit, the operating data stored in the working memory are stored in a non-volatile memory, and if the operating situation of the control unit is unclear, a reset of the control unit is initiated, during which the operating data from the working memory is deleted and the operating data from the non-volatile memory is loaded into the working memory. If the test device is connected and shutdown of the control unit has been initiated, the follow-up phase is enforced, and if shutdown has not been initiated and the test device is disconnected from the control unit, a reset of the control unit is carried out. The learning phase is maintained by means of a presence signal regularly transmitted by the test device. characterized in that, if there is no presence signal and shutdown of the control unit has not been initiated, the learning phase is terminated and a reset is carried out, with the loss of the learned operating data.

Description

[0001] The invention relates to a method for learning and storing operating data in a drive train of a motor vehicle according to the preamble of claim 1.

[0002] Motor vehicle drivetrains featuring an automated transmission driven by an internal combustion engine, such as a dual-clutch transmission, are known from series production applications. In order to execute the automatic functions of the transmission, including its friction clutch(es), using actuators, corresponding target variables are determined in a control unit and output to the actuators. For this purpose, operating data such as contact points of the friction clutch(es), gear end positions of transmission gears, and the like are learned during a learning phase at the end of the production line or after recommissioning in a workshop. For this purpose, a signal connection is established between the control unit and a test device, which automatically and / or under the control of a worker actuates the actuators provided for the learning process and determines operating data based on the signals generated by these actuators from sensors installed in the vehicle.In this case, actions may be performed that would be assessed as critical by a monitoring system for safety-relevant processes (Intelligent Safety Monitoring, ISM), known, for example, from DE 103 47 410 A1, and would initiate a reset of the control unit, resulting in the loss of the newly learned operating data stored in the volatile memory. Since the learning processes are performed in a secure environment away from the vehicle's driving operation, the monitoring system is deactivated during a learning phase.

[0003] DE 102 37 167 A1 discloses a method for controlling an automated manual transmission.

[0004] After the learning phase, the learned operating data must be transferred to a non-liquid memory in a secure manner and the deactivated monitoring system must be returned to the active state in a secure manner.

[0005] The object of the invention is therefore to further develop a method for learning and storing the operating data in a drive train of a motor vehicle, including secure storage of the learned operating data when the learning process has been successfully carried out and a clear treatment of the monitoring system.

[0006] The object is achieved by a method for operating a drive train of a motor vehicle containing an automated transmission with at least one friction clutch, with a control unit for controlling the transmission on the basis of learned and / or adapted operating data, in which a control unit is provided during driving operation of the motor vehicle, a monitoring system which is activated when the control unit is activated in order to avoid safety-relevant operating states of the transmission, and during a learning phase carried out by means of a test device which is in signal connection with the control unit, operating data of the drive train are learned and stored in a volatile working memory with the monitoring system deactivated,In a follow-up phase during a shutdown of the control unit, the operating data stored in the working memory are stored in a non-volatile memory, and if the operating situation of the control unit is unclear, a reset of the control unit is initiated, during which the operating data from the working memory is deleted and the operating data from the non-volatile memory is loaded into the working memory. If the test device is connected and the shutdown of the control unit has been initiated, the follow-up phase is enforced, and if the shutdown has not been initiated and the test device is disconnected from the control unit, a reset of the control unit is carried out.

[0007] This method proposes a clear sequence for completing a learning process, in which, depending on the signal connection between the test device and the control unit, the learned operating data is securely stored in a non-volatile memory such as a flash memory upon completion of the learning phase. To this end, a routine for controlling the learning phase is divided into two parts: a successful learning process, which results in the control unit being shut down, and an unsuccessful learning process, which results in a control unit reset.A successful learning process automatically deactivates the control unit, without being disrupted by further operations, and is preceded by a follow-up process in which the learned operating data is stored in the non-volatile memory. This deactivation subsequently requires a restart of the control unit. If the signal connection to the test device is lost, normal operation with the monitoring system activated is detected. If a repeat of the learning phase is desired, the monitoring system is deactivated again if the signal connection between the control unit and the test device is still present. A failed learning process can be terminated by disconnecting the signal connection between the control unit and the test device, which results in a reset, i.e. erasing the volatile main memory and reassigning the main memory with the operating data stored in the non-volatile memory.This includes reinitializing the control unit and activating the monitoring system in this way, allowing normal operation monitored by the monitoring system to continue with the original operating data. Forcing one of the two termination processes—shutdown or reset—prevents the initiation of operating states in which the monitoring system is deactivated outside of the learning phase.

[0008] According to the invention, the learning phase is maintained by means of a presence signal regularly transmitted by the test device. For example, the presence signal can be transmitted via a wired connector or a wireless connection. For example, the presence signal can be sent regularly, for example every 2 to 10, preferably every 5 seconds, by the test device and monitored by the control unit. According to the invention, if there is no presence signal and the control unit has not been shut down, the learning phase is terminated and a reset is performed, with the loss of the learned operating data. Furthermore, if there is no presence signal during the control unit shutdown, for example if the signal connection between the test device and the control unit is severed during the run-on period, a reset of the control unit is prevented.This prevents a successful learning phase from failing due to interruption of the run-on and thus preventing the learned operating data from being saved in the non-volatile memory if the learning phase is terminated prematurely by interrupting the signal line.

[0009] The proposed method also avoids the negative effects of deactivating the control unit with immediate reactivation, such as can occur, for example, through a rapid sequence of ignition on / off signals. In this case, the monitoring system can be deactivated during the learning phase before deactivation. After reactivation of the control unit, the monitoring system, which has not yet been deactivated by a reset or a complete deactivation with a run-on period, can remain deactivated if the cyclically transmitted presence signal is temporarily absent and normal operation is detected, which then proceeds without the monitoring system. To prevent such faulty operation, the proposed method can include a query that prevents an externally controlled reactivation of the control unit during a run-on period, for example, after a request from an ignition off signal.

[0010] The invention is explained in more detail with reference to the exemplary embodiment illustrated in the single figure. This shows a flowchart of the termination of a learning phase.

[0011] Flowchart 1 shows a sequence following a learning process for learning operating data such as clutch and transmission parameters for controlling a clutch torque depending on the actuation travel of a clutch actuator, for shifting transmission gears using selector and shift travel, synchronization thresholds, and the like. Initially in block 2, the learned operating data is stored in a volatile random access memory (RAM). The test device for performing the learning phase is in signal communication with the control unit. A monitoring system for monitoring safety-critical states of the control unit and the clutch or transmission actuators, which was switched off at the beginning of the learning phase, is still deactivated.

[0012] Branch 3 checks whether the shutdown of the control unit SG should be initiated, for example by checking whether an ignition switch, which is operated automatically by the test device or by a worker operating the test device, is present. If this is not the case, branch 4 checks whether the test device is in signal communication with the control unit by evaluating a presence signal. Instead of the presence signal, the system can also check for a false signal when the test device is disconnected, reversing the branch results. If a presence signal is detected, a branch is made before branch 3, so that a loop is processed until the shutdown of the control unit is initiated in branch 3. If no presence signal is detected, i.e. the signal connection between the control unit and the test device has been severed, the decision is made to abort the learning phase and the control unit is reset in block 5.In any case, the monitoring system is deactivated and reactivated. The operating data from the control unit's non-volatile memory is read into the main memory. Depending on the plausibility of this operating data, a new learning phase may be requested, an acoustic and / or visual error message may be issued, and / or an error log entry may be made, or normal operation of the vehicle may be initiated.

[0013] If an initiated shutdown is detected in branch 3, the control unit's run-on is started in block 6 by saving the data determined in the learning phase and stored in the volatile main memory to the non-volatile memory. Due to the longer duration of this process, a possible malfunction is prevented in branch 7 by a rapid reactivation of the control unit, for example by operating the ignition switch and generating an ignition-on signal. If this were to happen, the control unit could enter an undesirable or undefined operating state, for example, switching to normal operation in an uncontrolled manner while the monitoring system is still deactivated or switching to a reset if a presence signal is not detected, in which operating data not yet saved in the non-volatile memory is lost.Therefore, if a reactivation of the control unit is detected shortly after its shutdown has been initiated in branch 7, the reactivation of the control unit is prevented in block 8 and the follow-up is forcibly continued according to block 6. If reactivation is not detected, the follow-up process is continued.

[0014] For this purpose, branch 9 checks whether the presence signal is still present. If the presence signal is missing, or if it is suppressed elsewhere in the control system, for example due to application technology, or if the signal connection between the control unit and the test device is interrupted during this run-on phase, a reset of the control unit would be initiated immediately, which would in turn lose the learned operating data that is not yet saved in the non-volatile memory. If a missing presence signal is detected in branch 9, a normally running reset is prevented in block 10 and the run-on phase continues according to block 6. As long as the presence signal is present at branch 9, or after the reset is prevented in block 10, the storage of the operating data in the non-volatile memory continues in block 11 and, once this signal has been completed, the control unit is finally switched off in block 12. List of reference symbols 1 flowchart 2 blocks 3 Branching 4 Branching 5 blocks 6 blocks 7 Branching 8 blocks 9 Branching 10 blocks 11 blocks 12 blocks SG control unit

Claims

[1] Method for operating a drive train of a motor vehicle containing an automated transmission with at least one friction clutch, with a control unit for controlling the transmission on the basis of learned and / or adapted operating data, in which the control unit is provided with a monitoring system, which is activated when the control unit is activated, to avoid safety-relevant operating states of the transmission during driving of the motor vehicle, and during a learning phase carried out by means of a test device having a signal connection to the control unit, with the monitoring system deactivated, operating data of the drive train are learned and stored in a volatile working memory,wherein, in a follow-up phase during a shutdown of the control unit, the operating data stored in the working memory are stored in a non-volatile memory and, if the operating situation of the control unit is unclear, a reset of the control unit is initiated, during which the operating data of the working memory are deleted and the operating data of the non-volatile memory are loaded into the working memory, wherein, if the test device is connected and shutdown of the control unit has been initiated, the follow-up phase is enforced and, if shutdown has not been initiated and the test device is disconnected from the control unit, a reset of the control unit is carried out, wherein the learning phase is maintained by means of a presence signal regularly transmitted by the test device, characterized by that if there is no presence signal and the control unit has not been shut down, the learning phase is terminated and a reset is carried out, resulting in the loss of the learned operating data. [2] Method according to claim 1, characterized by that if there is no presence signal during shutdown of the control unit, a reset of the control unit is prevented. [3] Method according to one of claims 1 to 2, characterized by that an externally controlled reactivation of the control unit is prevented during a run-on.

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