Method and computing unit for calibrating a transmission

Abstract

The invention relates to a method for calibrating a transmission having an electrically driven actuator (1), having a first and a second gear, having a first and a second end stop (4, 6) between which an actuator region (2) extends, in which the actuator can be moved, a first gear is engaged when the actuator is in a first sub-region (8) of the actuator region surrounding the first end stop, a second gear is engaged when the actuator is in a second sub-region (10) of the actuator region surrounding the second end stop, and an electric drive of the actuator is actuated to move the actuator in the actuator region (2); the method comprises a partial calibration comprising: determining (10) which gear is engaged; if it is determined that the first or second gear is engaged, actuating (120; 160) until the actuator is located at the first or second end stop (4; 6), the actuator is moved starting from the first or second end stop using the stored association between the change in position of the actuator and the change in position of the drive.

Description

Technical Field

[0001] The invention relates to a method for calibrating a transmission as well as to a computing unit and a computer program for carrying out the method. Background Art

[0002] For movable driven machines, a transmission with two gears can be used. Due to the high torques to be transmitted, precise control is desirable for proper function with as little wear as possible. In particular, after an ignition reset, a shift actuator driven by means of an electric motor or its control device should be informed of the position in which the shift actuator is mechanically located, since usually a plurality of positions of the shift actuator correspond to a rotor angle of the electric motor. Summary of the invention

[0003] According to the invention, a method for calibrating a transmission and a computing unit and a computer program for carrying out the method are proposed, having the features of the independent patent claims. Advantageous embodiments are the subject matter of the dependent claims and the following description.

[0004] The present invention relates to a transmission with at least two gears, in which an actuator (shift actuator or transmission actuator) can move in an actuator region between two end stops, wherein a sub-region of the actuator region corresponds to the gear. The present invention uses measures to determine which gear of the transmission is engaged and to change the adjustment amount of the actuator drive device in such a way that the actuator abuts or stops at the following end stop, which is surrounded in a sub-region corresponding to the engaged gear. If the actuator is at the end stop, the corresponding end value of the adjustment amount is acquired and the correlation between the value of the adjustment amount and the actuator position is adjusted based on the acquired end value. This can be regarded as a partial calibration or a fast calibration. Such a calibration is advantageous because no gear shifting is required, so that no additional wear occurs and the calibration can be implemented quickly. In addition, the partial calibration can be implemented without depending on other components in the powertrain, so that the transmission does not have to wait for the release of all drive components. In short, the transmission is thus available at any time more quickly.

[0005] A computing unit according to the invention, such as a transmission or a control device of a machine in which the transmission is installed, is set up, in particular in terms of programming, to carry out the method according to the invention.

[0006] It is also advantageous to implement the method according to the invention in the form of a computer program or computer program product with a program code for carrying out all method steps, since this results in particularly low costs, in particular if the executing control device is also used for other tasks and is therefore already present. Suitable data carriers for providing the computer program are in particular magnetic, optical and electrical storage devices, such as hard disks, flash memories, EEPROMs, DVDs, etc. The program can also be downloaded via a computer network (Internet, intranet, etc.).

[0007] Further advantages and embodiments of the invention are apparent from the description and the drawings.

[0008] It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination but also in other combinations or alone, without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The invention is illustrated schematically in the drawings on the basis of exemplary embodiments and is described in more detail below with reference to the drawings.

[0010] Figure 1 An arrangement with an end stop and an actuator of a transmission is shown schematically, with the aid of which the relationship between actuator regions, end stops and gears is explained.

[0011] Figure 2 A flow chart according to a preferred embodiment is shown.

[0012] Detailed description of the drawings

[0013] Figure 1 The relationship between the actuator region 2, the end stops 4, 6 and the gear of the transmission is sketched. The actuator 1 can move between the first end stop 4 and the second end stop 6, which have a specific distance. The distance between the end stops can be determined, for example, in a complete calibration. If the actuator is in the first sub-region 8 of the actuator region 2, the first gear is engaged. The first sub-region 8 surrounds a position referred to as the first end position, in which the actuator stops or abuts against the first end stop 4. If the actuator is in the second sub-region 10 of the actuator region 2, the second gear is engaged. The second sub-region 10 surrounds a position referred to as the second end position, in which the actuator stops or abuts against the second end stop 6. The first sub-region 8 surrounds a first rated position 12, at which the actuator should ideally be when the first gear is engaged. The second sub-region 10 surrounds a second rated position 14, at which the actuator 1 should ideally be when the second gear is engaged. Unlike the illustrated case, the two sub-regions 8 and 10 can also be adjacent to each other.

[0014] The actuator 1 is driven or actuated by an electric drive (not shown), in particular an electromagnetic drive or an electric motor. If a desired position of the actuator is set, the electric drive is controlled in order to reach the desired position. However, for this purpose, the starting position and the relationship between the actuator movement and the drive movement must be known. When calibrating the actuator, these parameters can be determined, for example, by moving the actuator toward a stop, so that the corresponding current position can then be determined starting from there.

[0015] Furthermore, a calculation unit 20 is shown, which is used to control the transmission. The calculation unit 20 is particularly designed to control the drive of the actuator (for example via a control line not shown in detail). It can also be provided that the calculation unit 20 acquires position data or position data (for example angular position data or rotational speed of the drive) from a position sensor for the actuator.

[0016] During the full calibration, the actuator 1 is moved in such a way that it first comes to rest on one of the end stops and then on the other end stop. The known distance between the end stops (actuator movement) can be correlated with the drive movement (e.g., rotation of the motor, etc.), so that the respective current actuator position can be determined later. In particular, the correlation between the position change of the actuator and the position change of the drive can thus also be determined during the full calibration.

[0017] This complete calibration includes a shift through two gears. However, it is advantageously provided that only a partial calibration is carried out, in which only one of the end stops is reached and a shift is avoided. This procedure is carried out with the aid of Figure 2 To explain, Figure 2 A flow chart according to a preferred embodiment is shown.

[0018] In a preferred step 100, as described above, an (initial) complete calibration is performed. This complete calibration is performed, for example, immediately after the transmission is manufactured. The acquired end values ​​of the adjustment variable are stored, for example, in a control device, which is set up to implement the method. That is, the end values ​​for the first end position and the end values ​​for the second end position and the (initial) correlation between the position change of the actuator and the position change of the drive are known or stored. In each subsequent complete calibration that may be performed (see below), these stored values ​​are preferably replaced by the current values.

[0019] Further method steps are preferably carried out during normal operation (for example at certain times or in certain time intervals) and / or when starting the machine in which the transmission is installed.

[0020] In step 110 , it is determined which gear is engaged. This can be done by evaluating a gear signal of a transmission sensor or a position signal of a position sensor which detects the position of an actuator or of an element moved by the actuator.

[0021] If the first gear is engaged (e.g. the gear signal indicates that the first gear is engaged, or the position signal indicates that the actuator is in the first sub-range 8), the drive is actuated in step 120 until the actuator contacts the first end stop 4 and a corresponding value is determined as the position of the actuator. The corresponding direction is known (in which direction the drive must be moved in order to move the actuator toward the first end stop 4) because the basic functional relationship between the drive movement and the actuator position is known. Therefore, no gear change occurs. Starting from this end stop 4, all other positions can be reached using the stored relationship between the position change of the actuator and the position change of the drive.

[0022] Subsequently, the first target position 12 is reached in a preferred step 130. This takes place immediately after the first end stop has been reached, ie in particular without the second end stop being reached in the meantime.

[0023] Preferably, at a later time, after a shift into another gear, for example the second gear, during normal operation (which can be determined, for example, based on a gear signal and / or with the aid of a position sensor), a check of the partial calibration is carried out (preferred steps 140 to 170). For this purpose, in step 140 the drive is actuated until the actuator contacts the second end stop 6 and the corresponding position is ascertained from the position of the first end stop 4, the drive movement and the stored relationship. In step 150, it is checked whether a first deviation (more precisely, an absolute value of the first deviation) of the ascertained position from the expected position (i.e. the position expected when the actuator moves from the first end stop to the second end stop over a previously known distance) exceeds a first threshold value (the first threshold value and the second threshold value mentioned below can be specified as absolute values ​​or relative deviations).

[0024] If this is the case, a complete calibration (such as described above) is performed in step 160 . Preferably, the actuator is subsequently moved into the second target position in step 170 . Step 170 can be performed immediately after step 150 if the first deviation does not exceed the first threshold value.

[0025] Steps 140 to 170 are preferably only carried out when the transmission is torque-free, ie when no torque is being transmitted by the transmission, for example when the machine using the transmission is at a standstill.

[0026] If it is determined in step 110 that the second gear is engaged (for example, the gear signal indicates that the second gear is engaged, or the position signal indicates that the actuator is in the second sub-range 10), the drive is controlled in step 180 until the actuator 1 contacts the second end stop 6 and the corresponding value is determined as the position of the actuator. The corresponding direction is known (in which direction the drive must be moved in order to move the actuator 1 to the second end stop 6) because the basic functional relationship between the drive movement and the actuator position is known. Therefore, no gear change occurs. Starting from this end stop 6, all other positions can be reached using the stored relationship between the position change of the actuator and the position change of the drive.

[0027] The second target position 14 is reached in a preferred step 190. This takes place immediately after the second end stop has been reached, ie in particular without the first end stop being reached in the meantime.

[0028] Preferably, at a later time, after a shift into another gear, for example the first gear, during normal operation (which can be determined, for example, based on a gear signal and / or with the aid of a position sensor), a check of the partial calibration is carried out (preferred steps 200 to 230). For this purpose, in step 200 the drive is actuated until the actuator contacts the first end stop 4 and the corresponding position is ascertained from the position of the second end stop 6, the drive movement and the stored relationship. In step 210, it is checked whether a second deviation (more precisely, the absolute value of the second deviation) of the ascertained position from the expected position (i.e. the position expected when the actuator moves from the second end stop to the first end stop over a previously known distance) exceeds a second threshold value (the second threshold value can be equal to the first threshold value).

[0029] If this is the case, a complete calibration (such as described above) is performed in step 220 . Preferably, the actuator is subsequently moved into the first target position in step 230 . Step 230 can be performed immediately after step 210 if the second deviation does not exceed the second threshold value.

[0030] Steps 200 to 230 are preferably only carried out when the transmission is torque-free, ie when no torque is being transmitted by the transmission, for example when a machine using the transmission is at a standstill.

Claims

1. A method for calibrating a transmission having an electrically driven actuator (1), the transmission having a first gear and a second gear, wherein the transmission has a first and a second end stop (4, 6), between which an actuator region (2) extends, in which the actuator is movable, wherein the first gear is engaged when the actuator is in a first sub-region (8) of the actuator region enclosed by the first end stop, and the second gear is engaged when the actuator is in a second sub-region (10) of the actuator region enclosed by the second end stop, wherein an electric drive of the actuator is controlled in order to move the actuator in the actuator region (2); The method comprises a partial calibration comprising the following steps: Determine (110) which gear is engaged; If it is determined that the first gear is engaged, the drive device is controlled (120) until the actuator is at a first end stop (4), and the actuator is moved starting from the first end stop using the stored relationship between the position change of the actuator and the position change of the drive device; and If it is determined that the second gear is engaged, the drive device is controlled (160) until the actuator is at a second end stop (6) and the actuator is moved starting from the second end stop using a stored relationship between the position change of the actuator and the position change of the drive device.

2. The method according to claim 1, wherein: If it is determined in the partial calibration that the first gear is engaged, then after the partial calibration, when the second gear is engaged at a later point in time, the method furthermore comprises the following steps, in particular when the transmission is additionally torque-free: actuating (140) the drive device until the actuator is at a second end stop (6) and determining the position of the second end stop (6); Checking (150) whether a first deviation of the determined position of the second end stop (6) from a position of the second end stop (6) that is to be expected based on a correlation between a position change of the actuator and a position change of the drive device exceeds a first threshold value; If the first deviation exceeds a first threshold, performing a full calibration (160); In this case, after complete calibration, the actuator is preferably moved (170) into a second target position (14) in the second sub-region (10).

3. The method according to claim 1, wherein: If it is determined in the partial calibration that the second gear is engaged, then after the partial calibration, when the first gear is engaged at a later point in time, the method furthermore comprises the following steps, in particular when the transmission is additionally torque-free: actuating (200) the drive device until the actuator is at a first end stop (4) and acquiring corresponding values ​​of the drive device; Checking (210) whether a second deviation of the acquired value of the drive device from a value of the drive device that is expected based on a correlation between a position change of the actuator and a position change of the drive device exceeds a second threshold value; If the second deviation exceeds a second threshold, performing a full calibration (220); In this case, after complete calibration, the actuator is preferably moved (230) into a first target position (12) in a first sub-region (8).

4. The method according to claim 1, wherein an initial complete calibration (100) is performed, in particular when the transmission is manufactured or installed in a machine.

5. A method according to any one of claims 2, 3 or 4, wherein in the complete calibration (100, 160, 220) the drive device is controlled so that the actuator is moved until it abuts against one of the end stops (4, 6), and a corresponding first value of the drive device is obtained when the actuator abuts against one of the end stops, and then the actuator is moved until it abuts against the other end stop (4, 6), and a corresponding first value of the drive device is obtained; and wherein the saved association between the position change of the actuator and the position change of the drive device is re-determined or initially specified based on the first and second values.

6. The method according to any of the preceding claims, wherein the partial calibration further comprises the following steps: If it is determined that the first gear is engaged, the actuator is moved (130) to a first target position (12) in the first sub-region (8); or If it is determined that the second gear is engaged, the actuator is moved (190) into a second target position (14) in the second sub-region (10).

7. The method according to any one of claims 1 or 4 to 6, wherein If it is determined that the first gear is engaged, the actuator is moved starting from the first end stop (4) after partial calibration without actuating the drive device, so that the actuator is moved as far as the second end stop (6); or If it is determined that the second gear is engaged, the actuator is moved starting from the second end stop (6) after a partial calibration without actuating the drive device in order to move the actuator as far as the first end stop (4). 8 . The method according to claim 1 , wherein when determining ( 110 ) which gear is engaged, a signal of a position sensor or a gear sensor is detected and evaluated.

9. The method according to claim 1, wherein the method steps are performed with the start of the machine in which the transmission is installed and / or after the start at specific times, in particular at regular times, during the operation of the machine.

10. A computer unit (20) for controlling a transmission having an electrically driven actuator (1), the transmission having a first and a second gear, wherein the transmission has a first and a second end stop (4, 6), between which an actuator region (2) extends, in which the actuator is movable, wherein the first gear is engaged when the actuator is in a first sub-region (8) of the actuator region, which surrounds the first end stop, and the second gear is engaged when the actuator is in a second sub-region (10) of the actuator region, which surrounds the second end stop, wherein the electric drive of the actuator is controlled in order to move the actuator in the actuator region (2); The computing unit comprises a processor which is configured in such a way that it performs the steps of the method according to any of the preceding claims.

11. Computer program comprising instructions which, when the program is executed by a computer, cause the computer to perform the steps of the method according to any one of claims 1 to 9.

12. Computer-readable data carrier, on which a computer program according to claim 11 is stored.

Images