Method for adjusting a positioning unit of a steering column and an electrically adjustable steering column

Abstract

The present invention relates to an electrically adjustable steering column (1) for a motor vehicle, the electrically adjustable steering column comprising: a support unit (4) that adjustably holds a positioning unit (2); an adjustment device (5, 6) having an adjustment motor (7, 8) and designed for adjusting the positioning unit (2) relative to the support unit (4); mechanical adjustment stops (22, 23) that mechanically restrict the adjustment of the positioning unit (2) in a first adjustment direction (40); and a control unit (9). The control unit (9) is designed to activate the adjustment motor (7, 8) and defines a virtual adjustment stop upstream of the mechanical adjustment stops (22, 23) relative to the first adjustment direction (40). The steering column (1) is designed to adjust the positioning unit (2). In order to adjust the positioning unit (2), the positioning unit (2) is adjusted in the first adjustment direction (40) by means of the adjustment motor (7, 8), the positioning unit (2) being adjusted beyond the virtual adjustment stop according to a defined first provision. Then, the positioning unit (2) stops to reverse the direction, and the positioning unit (2) is adjusted to the holding position in the opposite direction of the first adjustment direction (40) according to the defined second provision and then stops.

Description

Technical Field

[0001] This invention relates to a method for adjusting a positioning unit of an electrically adjustable steering column for a motor vehicle, wherein the steering column includes: a support unit by which the positioning unit is adjustablely held; an adjustment device having an adjustment motor, the adjustment device being designed for adjusting the positioning unit relative to the support unit; and a mechanical adjustment stop that mechanically restricts the adjustment of the positioning unit in a first adjustment direction. For the positioning unit, a virtual adjustment stop is defined herein, the adjustment stop being located upstream of the mechanical adjustment stop relative to the first adjustment direction. The positioning unit is adjusted in the direction of the mechanical adjustment stop in the first adjustment direction by means of the adjustment motor at a first adjustment speed.

[0002] Furthermore, the present invention relates to an electrically adjustable steering column for a motor vehicle, the steering column comprising: a support unit through which a positioning unit is adjustablely held; an adjustment device having an adjustment motor, the adjustment device being designed for adjusting the positioning unit relative to the support unit; a mechanical adjustment stop mechanically limiting the adjustment of the positioning unit in an adjustment direction; and a control unit. The control unit of the steering column is designed to activate the adjustment motor. A virtual adjustment stop is defined herein, the adjustment stop being located upstream of the mechanical adjustment stop relative to a first adjustment direction. Background Technology

[0003] Electrically adjustable steering columns are known in the prior art. For example, US 2018 / 0079441 A1 discloses a steering column adjustable between a retracted position and an operating position. Furthermore, DE 10 2019 108 466 A1 discloses an adjustable steering column for a motor vehicle having a positioning unit and a support unit, wherein the steering column can be moved to a retracted position. The position of the positioning unit relative to the support unit is determined by means of a position recognition device, wherein the positioning unit is adjusted taking into account the determined position.

[0004] For steering wheel devices with electrically adjustable steering wheels, it is also known from EP 3 042 825 A1 to recognize a vehicle state in which the vehicle is not moving, wherein the steering wheel can automatically retract. In particular, the increase in driver comfort is associated with the aforementioned adjustment capability. Specifically, electrically adjustable steering columns with a so-called "easy-entry function" are known, wherein the positioning unit of the steering column adjusts from an operator-controlled position to a retracted position to facilitate easier entry into or exit from the vehicle. Here, a mechanical adjustment stop typically mechanically restricts the adjustment path of the positioning unit. That is, adjustment of the positioning unit beyond the mechanical adjustment stop is not possible.

[0005] However, since components of the adjusting device, such as the adjusting motor, may be damaged if the positioning unit is repeatedly adjusted against the mechanical adjusting stop at the normal adjusting speed, and especially if the positioning unit remains at the mechanical adjusting stop, virtual adjusting stops are known to be defined. The positioning unit typically reaches an end position at this virtual adjusting stop before reaching the mechanical adjusting stop. These virtual adjusting stops are defined such that they are positioned close to the mechanical adjusting stop. However, since deviations may occur when the position of the positioning unit is determined, especially when determining the position of the positioning unit by counting the rotor rotations of the adjusting motor using a Hall sensor is a cost-effective method, the distance between the mechanical adjusting stop and the virtual adjusting stop is chosen to be larger in order to reliably prevent the positioning unit from failing to adjust relative to the mechanical adjusting stop even if deviations occur in the position determination. However, this larger distance between the mechanical adjusting stop and the virtual adjusting stop is disadvantageous because a portion of the adjusting path, i.e., the adjusting path between the virtual adjusting stop and the mechanical adjusting stop, cannot be used. As a result, for example, a steering wheel that has been put into the stowed position will not move away from the driver as far as optimally defined virtual adjustment stops would allow. Summary of the Invention

[0006] Against this backdrop, the object of the present invention is to improve an electrically adjustable steering column and a method for adjusting the positioning unit of the electrically adjustable steering column. In particular, the object is to maximize the use of available adjustment paths. Furthermore, the object is particularly to reliably prevent damage to components of the steering column adjustment device. Additionally, the object is to advantageously find a solution that is as cost-effective as possible.

[0007] To achieve this objective, a method for adjusting the positioning unit of an electrically adjustable steering column and an electrically adjustable steering column are proposed. Other advantageous improvements of the invention are described in the specification and illustrated in the accompanying drawings.

[0008] The proposed solution provides a method for adjusting a positioning unit of an electrically adjustable steering column for a motor vehicle, wherein the steering column includes: a support unit by which the positioning unit is adjustablely held; an adjustment device having an adjustment motor designed for adjusting the positioning unit relative to the support unit; and a mechanical adjustment stop that mechanically restricts the adjustment of the positioning unit in a first adjustment direction. A virtual adjustment stop for the positioning unit is defined herein, the adjustment stop being located upstream of the mechanical adjustment stop relative to the first adjustment direction. Specifically, the virtual adjustment stop is in a non-operating position, particularly a retracted position, in which the positioning unit is held at the end of the adjustment path. In particular, the virtual adjustment stop is not defined as an absolute position relative to the adjustment path, but advantageously defined in relative terms as a position particularly relative to the positioning unit.

[0009] In the proposed method, the positioning unit is adjusted by means of an adjusting motor at a first adjusting speed in a first adjusting direction, wherein the positioning unit is adjusted beyond a virtual adjusting stop according to a defined first provision. Then, the positioning unit is stopped to reverse the direction, and the positioning unit is adjusted to a holding position against the first adjusting direction according to a defined second provision. The positioning unit then stops at the holding position. The holding position can then be, in particular, a retracted position. Specifically, the defined first provision predefines how far the positioning unit is adjusted beyond the virtual adjusting stop, i.e., particularly when the positioning unit stops to reverse the direction. The defined second provision predefines how far the positioning unit is adjusted against the first adjusting direction, i.e., particularly when the positioning unit stops to occupy the holding position. Specifically, the improved provision defines the same first and second provisions, and specifically defines the same distance, for example, a distance between 1 mm and 20 mm (mm: millimeter), with respect to which the positioning unit is adjusted.

[0010] Advantageously, by reversing the direction and limiting the adjustment of the positioning unit against the first adjustment direction, the positioning unit is prevented from remaining at the mechanical adjustment stop. Therefore, damage, particularly damage to the drive unit of the adjustment device, which could be caused by the positioning unit remaining at the mechanical adjustment stop, is advantageously prevented.

[0011] Specifically, the steering column is equipped with a control unit, which advantageously activates an adjustment motor, causing the adjustment unit to be adjusted in a first adjustment direction at a first adjustment speed. The positioning unit is adjusted beyond a virtual adjustment stop according to a defined first provision, the positioning unit stops to reverse direction, and the positioning unit is adjusted in the opposite adjustment direction to a holding position according to a defined second provision, and the positioning unit stops at the holding position. Advantageously, the position of the positioning unit is detected, particularly by means of a position detection unit.

[0012] In particular, the positioning unit is specified to be adjusted by means of a spindle drive, particularly as described in DE 10 2017 207 561 or DE 10 2020202 196, the contents of which are hereby explicitly referenced.

[0013] An advantageous improvement of the invention stipulates that the positioning unit's adjustment according to the defined first predetermined adjustment period is interrupted when the positioning unit reaches the mechanical adjustment stop. That is, specifically, the adjustment of the positioning unit is interrupted whenever the positioning unit reaches the mechanical adjustment stop before the defined first predetermined period is met, i.e., when the positioning unit adjusts a predetermined distance in the first adjustment direction. The advantageous effect achieved here is that, although another adjustment path is blocked by the mechanical adjustment stop, the adjustment motor is no longer further activated to further adjust the positioning device in the first adjustment direction. This advantageously prevents damage to the components of the adjustment device, particularly to the adjustment motor. The situation where the positioning unit reaches the mechanical adjustment stop before the defined first predetermined period is met may occur here, especially if there is a deviation or error in the determination of the positioning unit's position. In particular, whenever the rotation of the adjustment motor's rotor is detected by means of a Hall sensor, errors may occur in determining the position of the positioning unit by the number of rotor rotations, especially because the rotor rotations are sometimes not counted due to the hysteretic behavior of the Hall effect latching sensor.

[0014] According to another particularly advantageous development of the invention, the holding position occupied by the positioning unit after adjustment according to the defined second provision is defined as a new virtual adjustment stop. This new virtual adjustment stop is then advantageously defined as a virtual adjustment stop for the positioning unit. Thus, the new virtual adjustment stop replaces the previous virtual adjustment stop. Therefore, the virtual adjustment stop is advantageously calibrated. Specifically, it is stipulated that when the adjustment of the positioning unit according to the defined first provision is interrupted, the holding position occupied by the positioning unit after adjustment according to the defined second provision is defined as a new virtual adjustment stop, because the positioning unit has reached the mechanical adjustment stop during the adjustment according to the defined first provision. Specifically, if the defined first and second provisions are the same and relate to the adjustment distance, the advantageous effect achieved is that the distance between the newly defined virtual adjustment stop and the mechanical adjustment stop increases relative to the distance between the previous virtual adjustment stop and the mechanical adjustment stop, which may have been displaced, particularly due to errors in the determination of the positioning unit's position over time. The advantageous effect achieved here is that, during subsequent adjustments of the positioning unit along the first adjustment direction, the defined first requirement can be satisfied, and the positioning unit is adjusted to the mechanical adjustment stop to the maximum extent possible, but does not abut against the mechanical adjustment stop before the direction is reversed. Therefore, the components of the adjustment device are advantageously further protected, and thus the risk of failure of said components is further reduced.

[0015] According to another advantageous improvement of the invention, the first adjustment speed is reduced to a second adjustment speed. Advantageously, the first adjustment speed is reduced to the second adjustment speed when the defined proximity recognition condition has been identified as satisfied. Then, according to the defined first condition, the positioning unit is advantageously adjusted at the second adjustment speed past the virtual adjustment stop. This advantageously occurs at a lower speed when the positioning unit moves against the mechanical adjustment stop, resulting in even better prevention of damage to the components of the adjustment device. Furthermore, the acoustic behavior of the steering column is advantageously improved when the steering column approaches the end position of the adjustment path, particularly when the steering column approaches the retracted position. Advantageously, the positioning unit is therefore adjusted at a higher speed, which allows for rapid adjustment of the positioning unit and thus allows for rapid adjustment of the steering handle arranged on the positioning unit until the proximity recognition condition is satisfied, in which case the speed is subsequently reduced, advantageously continuously. The adjustment speed is advantageously reduced such that the positioning unit stops by means of continuous speed reduction when the defined first condition is satisfied. In particular, the proximity recognition condition is satisfied whenever the positioning unit has reached or maintained a predetermined distance from the virtual adjustment stop. Therefore, the proximity recognition condition is specifically identified as satisfied when the positioning unit has reached the predetermined distance from the virtual adjustment stop. Alternatively, the proximity recognition condition is specifically identified as satisfied when the positioning unit has reached the predetermined distance from the mechanical adjustment stop. Specifically, a speed between 10 mm / s (s: second) and 100 mm / s, particularly 70 mm / s, can be provided as the first adjustment speed. Specifically, a speed between 1 mm / s and 20 mm / s can be provided as the second adjustment speed.

[0016] Specifically, the proposed method specifies that during the adjustment of the positioning unit, the rotation of the rotor of the adjusting motor through a defined rotating portion is detected as rotational motion of the rotor in each case. For this purpose, a corresponding sensor unit is advantageously provided, particularly at least one Hall sensor. Here, the detected rotating portion is determined, in particular, by the number of magnetic poles of the rotor magnet. For example, in the case of a bipolar rotor magnet, the rotating portion will correspond to a full rotation of approximately 360°. Specifically, it is specified that the number of detected rotating portions from the position of the positioning unit is counted to determine the position of the positioning unit. Advantageously, the counter is reset at the end position of the adjustment path of the positioning unit, particularly at the mechanical adjustment stop and / or the virtual adjustment stop.

[0017] According to an advantageous development of this improvement, the first specified provision is that, after reaching the virtual adjustment stop, the positioning unit is further adjusted according to a predetermined number of rotational movements of the rotor, i.e., beyond the virtual adjustment stop. Specifically, it is specified that the positioning unit is adjusted beyond the virtual adjustment stop for two to twelve rotational movements of the rotor, particularly advantageously for three rotational movements of the rotor, and further particularly for three Hall effect ticks. Advantageously, the distance between the virtual adjustment stop and the mechanical adjustment stop here corresponds at least to a predetermined number of rotational movements of the rotor. The distance between the virtual adjustment stop and the mechanical adjustment stop is preferably greater than a predetermined number of rotational movements of the rotor, particularly greater than at least one rotational movement of the rotor.

[0018] According to another advantageous development, the second specified provision is that after the positioning unit stops in the reverse direction, the positioning unit is further adjusted according to a predetermined number of rotational movements of the rotor. Specifically, it is specified that for three to twelve rotational movements of the rotor, particularly advantageously for five rotational movements of the rotor, and further specifically for five Hall effect ticks, after the positioning unit stops in the reverse direction, the positioning unit is adjusted in the opposite direction to the first adjustment direction. Specifically, it can be specified that the positioning unit is adjusted according to a predetermined first number of rotational movements of the rotor according to the second specified provision. Specifically, it can be further specified that the positioning unit is adjusted according to a predetermined second number of rotational movements of the rotor according to the first specified provision. Preferably, the first number of rotational movements of the rotor is equal to the second number of rotational movements of the rotor.

[0019] An advantageous improvement specifies that the distance between the virtual adjusting stop and the mechanical adjusting stop is five rotational movements of the rotor. Advantageously, the first provision here specifies that the positioning unit is adjusted by three rotational movements of the rotor exceeding the virtual adjusting stop, and then stops to reverse the direction. Furthermore, the positioning unit is then advantageously adjusted in the opposite direction by three rotational movements of the rotor according to the second provision, and stops at the holding position that has been reached.

[0020] According to another advantageous embodiment of the invention, the first defined provision is that the positioning unit is adjusted to the mechanical adjustment stop. In this improved case, the positioning unit advantageously moves to the mechanical adjustment stop in a targeted manner, preferably at a speed reduced compared to the first adjustment speed. In this way, reliable calibration of the distance between the virtual adjustment stop and the mechanical adjustment stop is advantageously possible. In particular, the virtual adjustment stop is thus prevented from "migrating" away from the mechanical adjustment stop, and the adjustment path for the positioning unit is therefore shortened in long-term use due to errors in the determination of the positioning unit's position.

[0021] Another advantageous improvement of the invention stipulates that the load on the adjusting motor, particularly the motor voltage and / or motor torque, is detected and evaluated during the adjustment of the positioning unit. When a predetermined threshold for adjusting the motor load is exceeded, particularly when a predetermined motor voltage or predetermined motor torque is exceeded, it is advantageously identified that the positioning unit has reached the mechanical adjustment stop. Therefore, it is simple and cost-effective to identify that the positioning unit has been adjusted relative to the mechanical adjustment stop of the steering column. Thus, sensors on the mechanical adjustment stop, or multiple sensors on the mechanical adjustment stops, are advantageously unnecessary.

[0022] Another advantageous embodiment of the invention specifies that the method for adjusting the positioning unit is performed m times according to a defined first provision, wherein, after reaching the virtual adjustment stop, the positioning unit is further adjusted according to a predetermined second number of rotational movements of the rotor, and the method is performed m+1 times according to the defined first provision, wherein the positioning unit is adjusted to the mechanical adjustment stop. This has the advantage that for each m+1 time, the virtual adjustment stop is calibrated relative to the mechanical adjustment stop, and furthermore, adjustment of the positioning unit relative to the mechanical adjustment stop is generally prevented. In this case, "m" is advantageously a positive integer. In particular, the number m can be specified to fall between 2 and 1000. In particular, m can fall between 20 and 200. As a special improvement, it can be specifically stipulated, particularly for a predetermined operating cycle, that m=0 or m=1, and thus, when m=0, the positioning unit is always adjusted to the mechanical adjustment stop, while when m=1, after reaching the virtual adjustment stop, the positioning unit is always alternately further adjusted and / or adjusted to the mechanical adjustment stop according to a predetermined second number of rotational movements of the rotor.

[0023] A further proposed electrically adjustable steering column for motor vehicles, used to achieve the aforementioned objectives, includes a support unit and an adjustment device. A positioning unit is held adjustablely by the support unit. The adjustment device has an adjustment motor, particularly as described in DE 10 2017 207 561 or DE 10 2020 202 196, designed for adjusting the positioning unit relative to the support unit, the contents of which are explicitly referenced herein. Furthermore, the steering column includes a mechanical adjustment stop that mechanically restricts the adjustment of the positioning unit in a first adjustment direction. In addition to the mechanical adjustment stop, a virtual adjustment stop is defined. This virtual adjustment stop is located upstream of the mechanical adjustment stop relative to the first adjustment direction. Specifically, the virtual adjustment stop is configured for a holding position of the positioning unit, in which the positioning unit is held at the end of the adjustment path at the end of the adjustment process. In this respect, the virtual adjustment stop may specifically correspond to the retracted position of the positioning unit. Specifically, for the adjustment path, the steering column may, in each case, have a first mechanical adjustment stop located at a first end of the adjustment path and a second mechanical adjustment stop located at a second end of the adjustment path. Advantageously, a virtual adjustment stop is also defined for each mechanical adjustment stop. However, advantageously, the invention makes it possible to save mechanical adjustment stops, particularly because specific proximity to the mechanical adjustment stops leads to calibration, and therefore the second virtual adjustment stop, to which no mechanical adjustment stop is assigned, can be reliably approached by the positioning unit.

[0024] Specifically, the proposed steering column is designed for adjusting the positioning unit according to the method proposed to achieve the above-mentioned objectives, wherein the method may have the above-mentioned features individually or in combination. Specifically, the proposed steering column includes a control unit, wherein the control unit is advantageously designed to activate the adjustment motor of the steering column adjustment device, so that the positioning unit can be adjusted according to the described method steps. Specifically, the control unit is designed to activate the adjustment motor such that the positioning unit is adjusted by means of the adjustment motor at a first adjustment speed in a first adjustment direction, the positioning unit is adjusted beyond a virtual adjustment stop according to a defined first provision, the positioning unit stops in a reverse direction, the positioning unit is adjusted against the first adjustment direction to a holding position according to a defined second provision, and then the positioning unit stops at the holding position.

[0025] Advantageously, by reversing the direction and limiting the adjustment of the positioning unit against the first adjustment direction, the positioning unit is prevented from remaining at the mechanical adjustment stop. Therefore, damage that could occur due to the positioning unit remaining at the mechanical adjustment stop, particularly damage to the drive unit of the adjustment device, is advantageously prevented.

[0026] Furthermore, the proposed steering column advantageously includes a position detection unit. The position detection unit is advantageously designed to detect the position of the positioning unit relative to the support unit. In this case, the position detection unit is advantageously communicatively connected to the control unit. Therefore, the control unit can advantageously obtain information about the position of the positioning unit from the position detection unit, and can particularly use this information to activate the adjustment motor to execute the method proposed according to the invention. In particular, the position detection unit may include a linear sensor for determining the position. Advantageously, the position detection unit can be used, in particular, to approach a reference point for safety purposes.

[0027] Advantageously, the steering column, and especially the steering column position detection unit, has a sensor unit, particularly at least one Hall sensor. Advantageously, the sensor unit is designed to detect, in each case, the rotation of the regulating motor rotor through a defined rotary section as rotational motion of the rotor during adjustment of the positioning unit. This rotational motion of the rotor advantageously corresponds to a Hall count or Hall tick, i.e., in particular, the response of the Hall sensor. Specifically, in the case of a magnetic bipolar rotor, the rotational motion of the rotor is the complete rotation of the rotor, i.e., a rotation of approximately 360°, and is specifically counted as a Hall count or Hall tick. The sensor unit is advantageously communicatively connected to the control unit, so that the control unit can advantageously consider the rotational motion of the rotor when the regulating motor is activated.

[0028] Advantageously, the steering column, particularly the steering column position detection unit, includes a counter designed to count the number of rotational movements of the rotor, wherein the counter is advantageously communicatively connected to the control unit. Specifically, the position detection unit determines the position of the positioning unit by the number of rotational movements of the rotor. It is specifically stipulated here that the adjustment path of the steering column, particularly the adjustment path defined by the first and second mechanical stops, is allocated a fixed number of rotational movements of the rotor, advantageously necessary for adjusting the positioning unit from one end of the adjustment path to the other. In this way, advantageous position determination is advantageously achieved. Possible errors arising here, particularly those due to the Hall sensor's state changing from "high" to "low" between the adjustment motor's closure and reopening, are not significant here due to the advantageous activation of the adjustment motor, as already described, because calibration occurs automatically again. For further reduction, multiple Hall sensors can be provided.

[0029] Furthermore, advantageously, the steering column has a motor load detection unit. The motor load detection unit is advantageously designed to detect the load of the regulating motor during the adjustment of the positioning unit, particularly the motor voltage and / or motor torque. Advantageously, the motor load detection unit is also designed to assess whether the load of the regulating motor exceeds a predetermined threshold during the adjustment of the positioning unit, and in particular to identify whether the load of the regulating motor exceeds the predetermined threshold. Specifically, the motor load detection unit is communicatively connected to the control unit, allowing the control unit to advantageously consider the motor load during the activation of the regulating motor. Attached Figure Description

[0030] Other advantageous details, features, and improvements of the invention will be described in more detail with reference to the exemplary embodiments shown in the accompanying drawings (Figure: Drawings), in which:

[0031] Figure 1 shows a highly simplified schematic diagram of an exemplary embodiment of an installed steering column designed according to the present invention, the steering column having a retracted position ( Figure 1a ) and in operator-controlled position ( Figure 1b The steering handle;

[0032] Figures 2a to 2f A highly simplified schematic diagram of an exemplary embodiment of adjusting a positioning unit of a steering column or a steering handle arranged on a positioning unit based on a method designed according to the present invention is shown.

[0033] Figure 3 shows the first simplified three-dimensional view ( Figure 3a ) and with the second simplified stereoscopic diagram ( Figure 3b This illustrates another embodiment of the steering column designed according to the present invention;

[0034] Figure 4 Another embodiment of a method for adjusting a positioning unit for an electrically adjustable steering column, according to the present invention, is shown in the form of a sequence diagram;

[0035] Figure 5 A simplified perspective view of an exemplary embodiment of a steering system having a steering column designed according to the present invention is shown;

[0036] Figure 6 illustrates a schematic diagram of a technically possible adjustment space known in the prior art, which is used for a positioning unit having a virtual adjustment space within the adjustment space, such as at the beginning ( Figure 6a ) and after multiple adjustment cycles ( Figure 6b As defined by )

[0037] Figure 7 illustrates a schematic diagram of a technically possible adjustment space for a positioning unit having a virtual adjustment space, which can be implemented within the adjustment space according to the invention, such as at the beginning ( Figure 7a ) and after multiple adjustment cycles ( Figure 7b As defined by )

[0038] Figure 8 A schematic diagram illustrating an example of the adjustment cycle for a positioning unit is shown, wherein the method designed according to the present invention is not used; and

[0039] Figure 9 A schematic diagram illustrating an example of the adjustment cycle of a positioning unit that adjusts between a stowed position and an external operator-controlled position based on a method designed according to the present invention. Detailed Implementation

[0040] In the various figures, the same parts are usually given the same reference numerals, and therefore sometimes only one figure in each case is used for interpretation.

[0041] Figure 1a and Figure 1b A sketch is shown of an exemplary embodiment of an electrically adjustable steering column 1 installed in component 71 of a motor vehicle. Here, the steering column 1 includes a positioning unit 2 that is adjustable relative to a support unit of the steering column 1. In this exemplary embodiment, the positioning unit 2 includes a portion of a steering shaft, at the end of which a steering handle 3 is disposed. The steering column 1 also includes a control unit 9, which is designed to enable… Figure 1a and Figure 1b An adjustment motor, not explicitly shown in the diagram, is used to adjust the positioning unit 2 relative to the support unit. The positioning unit 2, and therefore the steering handle 3, can be specifically adjusted to occupy, as shown in the diagram. Figure 1a The collapsible position shown is 29 or as shown. Figure 1b The operator control positions shown are 26, 27, and 28.

[0042] Here, the stowed position 29 is the position that can be occupied in this exemplary embodiment when the driver wants to enter or leave the motor vehicle. Furthermore, in this exemplary embodiment, the stowed position 29 is occupied if the motor vehicle is in autonomous driving mode, in which the motor vehicle steers without driver intervention.

[0043] In contrast, operator control positions 26, 27, and 28 are those occupied in this exemplary embodiment when the driver steers the vehicle, i.e., when the vehicle is in manual driving mode. Different operator control positions 26, 27, and 28 are possible here, specifically except... Figure 1b Other operator control positions besides those shown are also possible. Operator control positions 26, 27, and 28 are preferably predefined individually for each driver or preset by the driver before first use of the motor vehicle, wherein the actual operator control positions 26, 27, and 28 can be specifically set according to the driver's height and the driver's personal preferences.

[0044] exist Figure 1a and Figure 1b In the exemplary embodiment illustrated, the retracted position 29 and operator control position 26 illustrated are, in each case, end positions along a possible adjustment path, in which the positioning unit 2 or steering handle 3 can be held.

[0045] Figure 1a and Figure 1b The switching element 78 is also illustrated by way of example. Actuation of the switching element 78 allows the driver to switch between automatic driving mode and manual driving mode, which usually also results in adjustment of the steering handle 3.

[0046] By way of example, it is assumed that the driver switches the vehicle from manual operation mode to automatic operation mode by actuating the switching element 78. As a result, the steering handle 3 is brought from the operator control positions 26, 27, 28 to the retracted position 29 along the adjustment path.

[0047] The following will refer to Figures 2a to 2f The adjustment of positioning unit 2 along the adjustment path and therefore the adjustment of steering handle 3 along the adjustment path will be explained in more detail here, wherein, Figures 2a to 2f This is a greatly simplified illustration. Specifically, Figures 2b to 2f The steering handle 3 is shown, but the positioning unit of the steering column is not explicitly shown, and therefore the following reference is to the steering handle 3 rather than the positioning unit.

[0048] exist Figures 2a to 2f In the exemplary embodiment shown, the adjustment path 55 is limited at each of its ends by mechanical adjustment stops 20, 21. The first mechanical adjustment stop 20 mechanically restricts the adjustment of the positioning unit, and thus restricts the adjustment of the steering handle 3 in the first adjustment direction 40. The second mechanical adjustment stop 21 mechanically restricts the adjustment of the positioning unit, and thus restricts the adjustment of the steering handle 3 in a second adjustment direction 41, opposite to the first adjustment direction 40. The adjustment directions 40, 41 are... Figures 2a to 2fThe arrows in the diagram represent the positions of the two objects. For the positioning unit, in each case, a first virtual adjustment stop 30 and a second virtual adjustment stop 31 are defined. The first virtual adjustment stop 30 is located upstream of the mechanical adjustment stop 20 relative to the first adjustment direction 40, and the second virtual adjustment stop 31 is located upstream of the mechanical adjustment stop 20 relative to the second adjustment stop 41. Here, in each case, the positioning unit can be adjusted beyond the first virtual adjustment stop 30 in the direction of the first mechanical adjustment stop 20 and beyond the second virtual adjustment stop 31 in the direction of the second mechanical adjustment stop 21. However, the positioning unit and therefore... Figures 2b to 2f The steering handle 3 can be permanently held only in the virtual adjustment stops 30 and 31, which are respectively the outermost points of the adjustment path 55. Therefore, in this exemplary embodiment, the first virtual adjustment stop 30 for the positioning unit corresponds to the retracted position 29 for the steering handle 3, and the second virtual adjustment stop 31 for the positioning unit corresponds to the outermost operator control position 26 for the steering handle 3.

[0049] Now targeting Figure 2b Assume that the steering handle 3 is intended to be moved from the operator control position 28 to the retracted position 29. To achieve this, the positioning unit therefore adjusts the steering handle 3 in the first adjustment direction 40 at a first adjustment speed using an adjustment device. The adjustment process is represented here by the steering handle 3, which is shown in dashed lines. Furthermore, for better illustration, details regarding the adjustment path 55 of the first virtual adjustment stop 30 are provided in... Figures 2c to 2f The image is shown in an enlarged format.

[0050] Then, the positioning unit or steering handle 3 is adjusted according to a defined first provision, in this exemplary embodiment, the defined first provision pre-limits the distance D to exceed the first virtual adjustment stop 30, such as Figure 2c As shown in the diagram. If a distance D is reached after the first virtual adjusting stop 30, the positioning unit or steering handle 3 stops for reversal of direction, as shown in the diagram. Figure 2d As shown in the illustration. Then, the positioning unit or steering handle 3 is adjusted according to a defined second provision, which in this exemplary embodiment is similarly reversed in the first adjustment direction 40, i.e., a predefined distance D in the second adjustment direction 41, such as... Figure 2e As shown, the positioning unit or steering handle 3 is adjusted until it reaches the holding position 50 generated by the distance D. The positioning unit or steering handle 3 then... Figure 2fThe device stops at the holding position 50 shown and remains there as an end position. In this exemplary embodiment, the holding position 50 coincides with the first virtual adjustment stop 30 and therefore with the retracted position 29. However, in particular, a situation not shown here may occur, especially due to an incorrect determination of the position of the positioning unit, where the holding position 50 does not coincide with the first virtual adjustment stop 30. In this case, it is specifically stipulated that the subsequently reached holding position is redefined as the subsequently applicable first virtual adjustment stop.

[0051] Figure 3a and Figure 3b An exemplary embodiment of a steering column 1 for a motor vehicle designed according to the present invention is illustrated from different angles. The steering column 1 is electrically adjustable. In this exemplary embodiment, the steering column 1 includes a support unit 4 having a multi-part design and a fastening device 10 for attaching the support unit 4 to a vehicle body (not shown). Furthermore, the steering column 1 includes a positioning unit 2 that is adjustablely held by the support unit 4. In this exemplary embodiment, in... Figure 3a and Figure 3b The height adjustability, indicated by the double arrow H, and the adjustability along the longitudinal axis L, indicated by the arrows in each case, are both possible. For both height adjustment and adjustment along the longitudinal axis L, the method for adjusting the positioning unit 2 according to the invention is advantageously used.

[0052] To adjust the positioning unit 2 in the first adjustment direction 40 and the second adjustment direction 41, the steering column 1 includes a first adjustment device 5 having a first adjustment motor 7. For height adjustability, the steering column 1 includes a second adjustment device 6 having a second adjustment motor 8.

[0053] The steering column 1 also includes a housing unit 80 having an outer housing tube 81, an intermediate housing tube 82, and an inner housing tube 83. The housing tubes 81, 82, and 83 are arranged axially so that they can be adjusted coaxially within each other in the axial direction of the longitudinal axis L, i.e., in a nested telescoping manner along a first adjustment direction 40 and a second adjustment direction 41. Within the housing unit 80, the steering spindle 84 is rotatably mounted about the longitudinal axis L and has a attachment point at its rear end. Figure 3a and Figure 3b The steering handle connection portion 85 is not shown in the diagram. Similar to the housing unit 80, the steering spindle 84 is also nested and telescopic in the longitudinal direction.

[0054] Regarding the adjustability of the positioning unit 2 in the direction of the longitudinal axis L, the positioning unit 2 includes an intermediate shell tube 82 and an inner shell tube 83, and a steering spindle 84 mounted in the inner shell tube. The support unit 4 includes a shell unit 80. To achieve longitudinal adjustment, the positioning unit 2 is housed in the outer shell tube 31 so that it can be displaced relative to the shell unit 3 in the direction of the longitudinal axis L in a telescoping manner, thereby allowing the steering handle, which is ultimately connected to the steering spindle 84, to be positioned forward and backward relative to the support unit 4 in the longitudinal direction, as indicated by arrows 40 and 41.

[0055] At the forward-facing end, a mechanical adjustment stop 22 is attached to the outer shell tube 81, protruding inward at the open end into the intermediate space between the outer shell tube 81 and the intermediate shell tube 82. During adjustment, the mechanical adjustment stop 22 mechanically restricts the adjustment of the intermediate shell tube 82 in the first adjustment direction 40, and thus fixes the intermediate shell tube 82 to prevent separation from the outer shell tube 81. Another mechanical adjustment stop 23, protruding inward into the intermediate space between the intermediate shell tube 82 and the inner shell tube 83, is attached to the forward-facing end of the intermediate shell tube 82, mechanically restricting the adjustment of the inner shell tube 83 and fixing the inner shell tube 83 to prevent it from being pulled out from the intermediate shell tube 82. Here, in each case, a virtual adjustment stop is defined for the positioning unit 2 upstream of the mechanical adjustment stops 22, 23. The corresponding virtual adjustment stops are located at a predetermined number of rotational movements of the rotor upstream of the corresponding mechanical adjustment stops 22, 23, particularly at five rotational movements of the rotor upstream of the stops in each case. Therefore, in a specific example, this means that the regulating motor 7 can also be further adjusted from the virtual regulating stops for five rotational movements of the rotor in the directions of the associated mechanical regulating stops 22, 23, until the positioning unit reaches and contacts the associated mechanical regulating stops 22, 23.

[0056] In an exemplary embodiment, the housing unit 80 of the steering column 1 is mounted in its rear region to allow it to pivot relative to the vehicle body about a horizontal pivot axis S, which is laterally positioned relative to the longitudinal axis L and is schematically illustrated. For this purpose, a pivot bearing (not shown) is arranged in the support unit 4 or between the support unit 4 and the vehicle body. In the front region, the housing unit 80 is connected to the support unit 4 via a positioning rod 11.

[0057] like Figure 3b As shown, the housing unit 80 can be adjusted, particularly together with the positioning unit 2, by means of the rotational movement of the positioning rod 11 via the second adjustment device 6 of the steering column 1, about the pivot axis S which is horizontally arranged in the installed state relative to the support unit 4. Therefore, in particular, the adjustment of the steering handle attached to the connecting portion 85 can be performed in the vertical direction indicated by the double arrow H.

[0058] The first adjustment device 5 of the steering column 1 is designed for longitudinal adjustment of the positioning unit 2 relative to the housing unit 80 in a first adjustment direction 40 and a second adjustment direction 41. In this exemplary embodiment, the first adjustment device 5 has a spindle driver with a spindle nut 12 having an internal thread 13 extending along the spindle axis G, and a threaded spindle 14 engaging in the internal thread 13, i.e., the threaded spindle 14 is screwed into the corresponding internal thread 13 of the spindle nut 12 using its external thread. In this exemplary embodiment, the threaded spindle axis of the threaded spindle 14 is the same as the spindle axis G and extends substantially parallel to the longitudinal axis L.

[0059] The spindle nut 12 is rotatably mounted in the bearing housing 15 about the spindle axis G, and the bearing housing 15 is fixedly connected to the outer housing tube 81 of the housing unit 80. In the direction of the spindle axis G, the spindle nut 12 is axially supported on the housing unit 80 via the bearing housing 15. In this exemplary embodiment, the adjusting device 5 is correspondingly referred to as a plunger-type spindle drive.

[0060] The free end of the threaded spindle 14 is connected at arm 16 to the inner shell tube 83 for co-rotation and is axially fixedly supported. The spindle nut 12 is axially, i.e., longitudinally, supported on the outer shell tube 81 via the bearing housing 15 and the first adjusting motor 7. The longitudinal direction corresponds to the direction of the longitudinal axis L. Relative rotation by means of the adjusting motor 7 of the adjusting device 5 causes the threaded spindle 14 and the spindle nut 12 to move together or separately depending on the direction of rotation. Therefore, the inner shell tube 83 retracts axially into the intermediate shell tube 82 along the first adjusting direction 40, while the intermediate shell tube 82 enters the outer shell tube 81 along the first adjusting direction 40, or the inner shell tube extends along the second adjusting direction 41. Thus, the steering handle attached to the connecting portion 85 can be adjusted as follows: Figure 1a The collapsed position 29 shown in the sketch is either adjusted to, or... Figure 1b The operator control positions 26, 27, and 28 are shown in the sketch. In the retracted position 29, the inner shell tube 83 and the intermediate shell tube 82 are retracted into the outer shell tube 81. In the operator control positions 26, 27, and 28, the shell tubes 81, 82, and 83 extend separately from each other in a nested telescoping manner.

[0061] exist Figure 3bThis shows how the second adjustment device 6 is attached to the steering column 1 for vertical adjustment. The second adjustment device 6 is constructed in principle in the same manner of operation as the first adjustment device 5. The second adjustment device 6 also includes a spindle nut 17, with a threaded spindle 18 engaged in the internal thread of the spindle nut 17 along the spindle axis G. The threaded spindle 18 is rotatably mounted in a bearing housing 19 about the axis G. The bearing housing 19 is fastened to the housing unit 80 and axially supported on the housing unit 80 along the direction of the axis G, and can be optionally driven in a rotational manner in two rotational directions about the axis by the second adjustment motor 8.

[0062] In the illustrated embodiment, the adjusting devices 5 and 6 of the steering column 1 are referred to as plunger-type spindle drives. Alternatively, a rotary spindle drive can also be specifically formed, wherein the spindle nut 12 or 17 is held in rotation on the steering column 1, and the threaded spindle 14 or 18 can be driven in a rotary manner by an adjusting motor 7 or 8.

[0063] The second adjustment device 6 acts on the end of the double-arm positioning rod 11 mounted on the support unit 4 so as to be able to rotate about the pivot bearing 72, and the other arm of the positioning rod is connected to the housing unit 80 in another pivot bearing 73 at the other end.

[0064] In this exemplary embodiment, the first regulating motor 7 and the second regulating motor 8 of the regulating devices 5 and 6 each include Hall sensors 75 and 76, respectively. The Hall sensors 75 and 76 are only used in... Figure 3a and Figure 3b The diagram is schematically illustrated. During adjustment of the positioning unit 2 along the longitudinal axis L, the rotation of the rotor of the adjusting motor 7 about a defined rotating portion is detected as rotational movement of the rotor in each case by means of the Hall sensor 75 of the first adjusting motor 7. Specifically, it is stipulated that a full rotation of the rotor is detected here in each case. Correspondingly, during height adjustment H of the positioning unit 2, the rotation of the rotor of the adjusting motor 8 through the defined rotating portion is detected as rotational movement of the rotor in each case by means of the Hall sensor 76 of the second adjusting motor 8. Specifically, it is stipulated that a full rotation of the rotor is detected here in each case.

[0065] The steering column 1 also includes a control unit 9, which is also only located in... Figure 3a and Figure 3bThe diagram is schematically illustrated. Control unit 9 is designed here to activate adjusting motors 7 and 8. In this exemplary embodiment, Hall sensors 75 and 76 are also communicatively connected to control unit 9, and detected rotational motion of the rotor is supplied to control unit 9. Control unit 9 includes a position detection unit 90, which is designed to determine the position of positioning unit 2 relative to support unit 4 based on the rotational motion of the rotor detected by Hall sensors 75 and 76. The relationship between the rotational motion of the rotor and the rotation of the corresponding threaded spindles 14 and 18, and the resulting adjustment path of positioning unit 2, are considered here.

[0066] The control unit 9 of the steering column 1 is also designed to activate the adjustment motors 7 and 8, so that the positioning unit 2 is adjusted relative to the support unit 4, specifically according to the adjustment specifications. In particular, the control unit is designed to perform the following (see reference below). Figure 4 The method explained. Figure 4 This is shown as a sequence diagram, according to which the adjustment of the steering column positioning unit relative to the steering column support unit can be performed.

[0067] exist Figure 4 In the exemplary embodiment shown, in method step 100, the control unit 9 receives a command to bring the positioning unit to the stowed position. In step 101, a counter is used to detect which specific adjustment process is to begin, and in step 102, the positioning unit is adjusted by means of an adjustment motor at a first adjustment speed in a first adjustment direction. This is particularly relevant to the following... Figure 3a and Figure 3b The steering column is specified, and the positioning unit 2 is adjusted along the first adjustment direction 40 in the direction of the longitudinal axis L. Here, the first adjustment speed can be 60 mm / s. During adjustment, in another step 200, it is checked whether a defined proximity recognition condition is met. If the positioning unit has reached a distance from the virtual adjustment stop, the proximity recognition condition is considered to be met, the distance being defined by a predetermined number of rotational movements of the rotor. Specifically, it is specified that the proximity recognition condition is met if the positioning unit is moved away from the virtual adjustment stop by the rotor in twenty rotational movements. If the proximity recognition condition (N) is not met, the positioning unit is further adjusted at the first adjustment speed. If the proximity recognition condition (Y) is met, in step 103, the adjustment speed of the positioning unit is reduced to a second adjustment speed lower than the first adjustment speed, specifically reduced to an adjustment speed of 5 mm / s.

[0068] Furthermore, in step 201, it is checked whether the adjustment process is the (m+1)th adjustment process. This step can also be taken from the beginning. The reason is that, in this exemplary embodiment, it is specified that each (m+1)th adjustment process is executed differently from the previous m adjustment processes in each case. In particular, each eightieth adjustment process can be executed differently from the previous seventy-nine adjustment processes.

[0069] If the test shows that this is not the (m+1)th adjustment process, then in step 110, after reaching the virtual adjustment stop, the positioning unit further adjusts in the first adjustment direction at a reduced second adjustment speed based on a predetermined number of rotational movements of the rotor, specifically four rotational movements of the rotor. In this process, firstly in step 210, it is checked whether the adjustment motor has performed the predetermined number of rotational movements of the rotor. If this is not the case (N), then in another step 211, it is also checked whether the positioning unit has reached the mechanical adjustment stop. Here, the arrival of the mechanical adjustment stop can be specifically detected by monitoring the increase in motor voltage upon reaching the mechanical adjustment stop.

[0070] If the mechanical adjustment stop (N) has not been reached and the predetermined number of rotational movements (N) of the rotor has not been performed, the positioning unit is further adjusted in the first adjustment direction at a reduced second adjustment speed. Conversely, if the adjustment motor has performed the predetermined number of rotational movements (Y) of the rotor or the positioning unit has reached the mechanical adjustment stop (Y), the adjustment motor and therefore the positioning unit stop in step 104 for reversal of direction. During the (m+1)th adjustment, the positioning unit is intentionally adjusted to the mechanical adjustment stop to calibrate the virtual adjustment stop. Therefore, in step 120, the positioning unit is adjusted in the direction of the mechanical adjustment stop, i.e., the first adjustment direction, at a reduced second adjustment speed. In step 220, it is checked whether the positioning unit has reached the mechanical adjustment stop. If not (N), the positioning unit is further adjusted. When the mechanical adjustment stop (Y) is reached, the positioning unit also stops in step 104 for reversal of direction.

[0071] After stopping according to step 104, in step 105, the positioning unit is adjusted in the opposite direction to the first adjustment direction, i.e., away from the mechanical adjustment stop, according to a predetermined number of rotational movements of the rotor. Specifically, the number of four rotational movements of the rotor is also specified here. Furthermore, in step 202, it is checked whether the adjusting motor has performed the predetermined number of rotational movements of the rotor. If no (N), the positioning unit is further adjusted. Otherwise (Y), the positioning unit stops in step 106. The retracted position is reached, and the positioning unit remains in the held position until a further adjustment request is received.

[0072] Furthermore, in this exemplary embodiment, the holding position is defined as a new virtual adjustment stop in step 107. Here, the newly defined virtual adjustment stop replaces the previously defined virtual adjustment stop. Therefore, the virtual adjustment stop is continuously calibrated. Figure 4 In the improved variant not illustrated, the new definition of the virtual adjustment stop also occurs only in each (m+1)th adjustment process, during which the positioning unit is intentionally adjusted to the mechanical adjustment stop.

[0073] Figure 5 An exemplary embodiment of an electromechanical steering system 92 of a motor vehicle with a steering column 1 is shown, which may be particularly as described in reference to Figure 3a and Figure 3b Design it as described. As... Figure 5 An alternative to the steering system 92 shown in the diagram can also be a steer-by-wire system.

[0074] Figure 5 The steering system 92 illustrated includes a steering column 1 having a steering shaft and a steering handle 3 connected to the steering shaft for joint rotation and designed as a steering wheel in this exemplary embodiment. Here, the driver can predefine steering commands in a known manner by rotation via the steering handle 3. The steering column 1 is mechanically coupled to the steering wheels 94 of the motor vehicle via a steering mechanism 93. The steering mechanism 93 includes a pinion 98 controlled by a steering actuator 95 and a toothed connecting rod 96. The steering mechanism 93 is used here to convert the rotational motion of the pinion 98 into translational motion of the connecting rod 96 along its longitudinal axis. The connecting rod 96, which moves linearly along its longitudinal axis, is mechanically coupled to tie rods 99 located on both sides of the motor vehicle in each case. The tie rods 99 are, in turn, mechanically coupled to the wheels 94 in each case.

[0075] Figures 6a to 7b An adjustment space 60 is schematically shown, which can be used, by way of example, to adjust the positioning unit in the longitudinal adjustment direction L and the height adjustment direction H and is limited by a mechanical adjustment stop. In the prior art, it is known to define a virtual adjustment space 61, also known as an adjustment window, which is significantly smaller than the adjustment space 60, and the positioning unit is actually adjusted in the virtual adjustment space 61. Figure 6a and Figure 7a Here are shown adjustment spaces having virtual adjustment space 61 and virtual adjustment space 62 defined at the beginning.

[0076] The difference between the adjustment space 60 and the virtual adjustment space 61, or the corresponding mechanical adjustment stop and the associated virtual adjustment stop, has so far been chosen to have a size such that, Figure 6a and Figure 6b As illustrated, this ensures that the accumulated Hall count error is always less than the distance between the mechanical adjustment stop and the associated virtual adjustment stop. If the adjustment motor is permanently held at the mechanical adjustment stop, this can lead to damage or even failure of the steering column adjustment mechanism.

[0077] Here, the Hall counting error arises from the use of a Hall sensor in the regulating motor, for example, the Hall sensor emits a "high" state when the regulating motor is off and a "low" state when the regulating motor is on again. This is primarily based on the hysteretic behavior of the Hall effect latching sensor. Due to the different holding positions, this error is partially, but not completely, averaged again. One reason is that the hysteresis behavior of the sensor is not perfectly asymmetrical. Mechanical changes in position due to vibration can also lead to changes in the signal state. The voltage supply to the sensor cannot be kept permanently on, as this would exceed a certain quiescent current consumption. If the level differs from the off state during the period when the voltage supply to the Hall sensor is on, the direction of rotor movement of the regulating motor cannot be determined. To minimize this error, it is advantageous not to immediately cut off the power supply after this process, but to continue supplying it for several 100 ms (ms: milliseconds). Commercially available Hall sensors used in DC motors, such as regulating motors in steering columns, do not have any direction recognition. The bounce of the position is therefore considered as forward movement, since the direction predefined by the motor is always assumed in the case of self-locking drive. When using a second Hall sensor in the motor, a 90° offset can advantageously reduce, but not completely eliminate, the Hall count error. However, this approach leads to increased component costs. An absolute position sensor system for height / length can similarly address this issue, but it is expensive. If, for safety reasons, the position of the positioning unit determined based on motor revolutions is compared to the absolute position, particularly relative to the airbag area and / or the comfort / collapse area, using area and / or length sensors, then this error must be minimal, for example, less than + / - 1 mm to 2.5 mm as a closure criterion.

[0078] With the adjustment device having an increased maximum speed, the motor rotation speed of the adjustment motor is specifically configured to 3000 revolutions per minute. However, the resulting speed is specifically 70 mm / s instead of 12 mm / s. The higher transmission ratio requires an increased distance between the virtual adjustment stop and the mechanical adjustment stop, particularly an increase of five to six times.

[0079] It appeared after multiple adjustment processes and Figure 6b and Figure 7b The offset in the position of the virtual adjustment space, as illustrated in the example, is particularly noticeable with larger gear ratios, and even small offsets are visible to the naked eye when the retractable steering column is folded down flush with the steering wheel surface. Furthermore, one issue is that the actual available adjustment space is not being fully utilized.

[0080] Using the proposed method for adjusting the steering column positioning unit, the adjustment space 60 and the virtual adjustment space 62 can now be advantageously and significantly moved closer together, and the virtual adjustment space can therefore be expanded, such as... Figure 7a and Figure 7b As shown in the diagram. Due to the new definition of the virtual adjustment stop, it is also advantageous from, for example... Figure 7b The state shown in the image returns to the state shown in the image. Figure 7a The state shown, or at least roughly returned to, is as follows: Figure 7a The state shown in the figure.

[0081] Specifically, when the positioning unit moves to the end position, the corresponding mechanical adjustment stop is "scanned," and then the positioning unit retracts again so as not to remain at the mechanical adjustment stop. For this adjustment, closed-loop control is particularly provided, especially at low speeds, i.e., with few Hall counts. For this closed-loop control, particularly for PID controllers (PID: Proportional-Integral-Derivative), a regulating motor with at least four Hall counts per revolution is advantageous. Particularly good results can be achieved by returning from three rotor revolutions to five rotor revolutions. It has been shown that in this case, mechanical tension is reduced and approach shock is decreased when approaching the mechanical adjustment stop.

[0082] This value is advantageously determined based on the corresponding steering column and the corresponding adjustment device.

[0083] Figure 8 and Figure 9 The diagrams illustrate the adjustment cycle V of the positioning unit between the retracted position 29 and the outermost operator control position 26. In each case, the position of the positioning unit is plotted on axis X during rotor rotation. The number of rotor rotations corresponds here to the number of Hall effect counts. The adjustment speed, in mm / s, is plotted on axis Z. The retracted position 29 corresponds here to the first virtual adjustment stop 30, and the operator control position 26 corresponds to the second virtual adjustment stop 31.

[0084] Figure 8 The adjustment cycle shown here does not use the method according to the invention, and therefore the critical displacement of the virtual adjustment stops 30, 31 may occur due to Hall count errors. Figure 8In the case of the adjustment gradient shown, the positioning unit is adjusted, for example, from the retracted position 29 to the operator control position 26. During this process, the adjustment speed initially increases continuously until it reaches an adjustment speed of 12 mm / s. Then, the adjustment speed decreases after approximately thirteen rotor rotations upstream of the operator control position 26, causing the positioning unit to stop at the operator control position 26.

[0085] Figure 9 The adjustment cycle shown utilizes the method according to the invention. The difference between the first mechanical adjustment stop 20 and the first virtual adjustment stop 30 is chosen to be as small as possible. When the adjustment cycle reaches one of the limiting positions, i.e., when it cycles to the retracted position 29 or the outermost operator control position 26, the mechanical adjustment stop 20 is intentionally approached slowly, but typically this approach does not go far to the mechanical adjustment stop 20, and then the movement returns again. This results in a triangular negative adjustment gradient during the approach to the retracted position 29 or during the approach to the operator control position 26.

[0086] This prevents the adjustment device from being held at the mechanical adjustment stop 20 and avoids damage to the components of the adjustment device. Furthermore, cyclic calibration of the virtual adjustment stop is no longer necessary but can be provided. In addition, the usable adjustment window, i.e., the virtual adjustment space, is maximized. Acoustic characteristics are also improved when approaching the corresponding limit position.

[0087] The distance between the virtual adjustment stop and the mechanical adjustment stop should be advantageously chosen to be as small as possible, especially when the adjustment device has a high adjustment speed. Specifically, in one exemplary embodiment, five Hall counts can be selected based on the distance. During the adjustment of the positioning unit to the retracted position 29, three Hall counts are adjusted via the virtual adjustment stop 30, and then slowly returned to the target position 29. Advantageously, especially when using a single-count Hall sensor, the Hall count for mechanical tolerance is added to the two Hall counts on the adjustment path return. If a Hall count is lost or additionally counted, the distance to one side of the mechanical adjustment stop 20 decreases, and this distance is detected at a continuously decreasing adjustment speed during passage, i.e., at a reduced second adjustment speed. Therefore, it is ensured that there is never a static stop at the mechanical adjustment stop 20. The adjustment window is recalibrated online.

[0088] Advantageously, a collision / clamping distinction is provided based on the intended end position, which is particularly relevant to safety. If one of the end positions 29, 26 is not approached or only one end position exists, the mechanical adjustment stop 20 at the retracted position 29 can be intentionally approached periodically. This online calibration is advantageously performed without requiring additional adjustment cycles for the user of the steering column, or is imperceptible to the user of a motor vehicle with a mounted steering column. Advantageously, the number of unplanned calibrations is considered in the diagnostic protocol, particularly in the control unit. With this in mind, a complete calibration can then be performed during garage visits, especially when the mechanical adjustment window is changed, for example, due to dirt or foreign objects.

[0089] The exemplary embodiments illustrated in and explained in conjunction with the accompanying drawings are used to explain the invention and not to limit it.

[0090] List of reference numerals

[0091] 1. Steering column

[0092] 2 Positioning Unit

[0093] 3. Steering handle

[0094] 4 Support Units

[0095] 5, 6 Adjustment devices

[0096] 7, 8 Adjust the motor

[0097] 9 Control Unit

[0098] 10 Fastening device for support unit (4)

[0099] 11. Positioning rod

[0100] 12, 17 Spindle Nuts

[0101] 13. Internal thread of spindle nut (12)

[0102] 14 and 18 threaded spindles

[0103] 15, 19 Bearing housings

[0104] 16 arms

[0105] 20 First mechanical adjustment stop

[0106] 21 Second mechanical adjustment stop

[0107] 22, 23 Mechanical adjustment stops

[0108] Operator control positions 26, 27, and 28

[0109] 29 Collapse location

[0110] 30 First virtual adjustment stop

[0111] 31 Second virtual adjustment stop

[0112] 40 First adjustment direction

[0113] 41 Second adjustment direction

[0114] 50. Maintain position.

[0115] 55 Adjustment Path

[0116] 60 Adjustable space

[0117] 61, 62 Virtual adjustment space

[0118] 71 Components of a motor vehicle

[0119] 72, 73 Pivot bearings

[0120] Hall sensors 75 and 76

[0121] 78 Switching Components

[0122] 80 shell units

[0123] 81 Outer casing tube

[0124] 82 Intermediate Shell Tube

[0125] 83 Inner shell tube

[0126] 84 Steering spindle

[0127] 85 Connection part of steering spindle (84)

[0128] 90 Position Detection Unit

[0129] 92 Steering System

[0130] 93 Steering Mechanism

[0131] 94 rounds

[0132] 95 Steering actuator

[0133] 96 Connecting rod

[0134] 98 small gears

[0135] 99 tie rods

[0136] D Distance

[0137] G spindle axis

[0138] H is a double arrow used to indicate high adjustability.

[0139] L longitudinal axis

[0140] S Pivot axis

[0141] N test adjustment not met

[0142] Y test adjustment satisfied

[0143] Adjustment gradient between the operator control position and the collapsed position of V storage

[0144] X indicates the axis of rotation of the rotor (Hall count).

[0145] Z indicates the axis of adjustment speed in mm / s.

[0146] The 100 control unit receives a command to adjust the positioning unit to the retracted position.

[0147] 101 A specific adjustment process has been detected to have begun.

[0148] 102 The positioning unit is adjusted in the first adjustment direction at a first adjustment speed by means of an adjustment motor.

[0149] 200 Check if the proximity recognition conditions are met.

[0150] 103. Reduce the first adjustment speed to the second adjustment speed.

[0151] 201. Check if the adjustment operation is the (m+1)th adjustment process.

[0152] 110 After reaching the virtual adjustment stop, the positioning unit is adjusted at a reduced second adjustment speed according to a predetermined number of rotor rotation movements.

[0153] 210 Check whether the regulating motor has performed the predetermined number of rotor rotations.

[0154] 211 Check whether the positioning unit has reached the mechanical adjustment stop.

[0155] 120. Adjust the positioning unit to the mechanical adjustment stop at a reduced second adjustment speed.

[0156] 220 Check if the positioning unit has reached the mechanical adjustment stop.

[0157] 104. Stop the positioning unit for orientation reversal.

[0158] 105. Adjust the positioning unit counter to the first adjustment direction according to the predetermined number of rotor rotation movements.

[0159] 202 Check whether the regulating motor has performed the predetermined number of rotor rotations.

[0160] 106 Stop the positioning unit

[0161] 107 The holding position is defined as the new virtual adjustment stop, and the positioning unit has stopped at the holding position.

Claims

1. A method for adjusting a positioning unit (2) of an electrically adjustable steering column (1) for a motor vehicle, wherein, The steering column (1) includes: a support unit (4) by which the positioning unit (2) is held in an adjustable manner; an adjustment device (5, 6) having an adjustment motor (7, 8) designed to adjust the positioning unit (2) relative to the support unit (4); and mechanical adjustment stops (20, 21, 22, 23) mechanically restricting the adjustment of the positioning unit (2) in a first adjustment direction (40), wherein virtual adjustment stops (30, 31) are defined for the positioning unit (2). The component is located upstream of the mechanical adjustment stops (20, 21, 22, 23) relative to the first adjustment direction (40), and wherein the positioning unit (2) is adjusted in the first adjustment direction (40) at a first adjustment speed by means of the adjustment motor (7, 8), characterized in that the positioning unit (2) is adjusted according to a defined first provision until it exceeds the virtual adjustment stop (30); the positioning unit (2) stops to reverse the direction; the positioning unit (2) is adjusted to a holding position (50) against the first adjustment direction (40) according to a defined second provision; and the positioning unit (2) then stops at the holding position (50).

2. The method according to claim 1, characterized in that, When the positioning unit (2) reaches the mechanical adjustment stop (20, 21, 22, 23) during the adjustment period defined in the first specified time, the adjustment of the positioning unit (2) is interrupted according to the first specified time.

3. The method according to claim 1 or claim 2, characterized in that, The holding position (50) is defined as a new virtual adjustment stop (30, 31), and therefore the new virtual adjustment stop is defined as the virtual adjustment stop (30, 31) for the positioning unit (2).

4. The method according to any one of claims 1-2, characterized in that, When the defined proximity recognition condition has been recognized as satisfied, the first adjustment speed is reduced to the second adjustment speed, wherein the positioning unit (2) is adjusted to exceed the virtual adjustment stop (30, 31) at the second adjustment speed according to the defined first provision.

5. The method according to claim 4, characterized in that, When the positioning unit (2) has reached a limited distance (D) from the virtual adjustment stop (30, 31), the proximity recognition condition is recognized as satisfied.

6. The method according to any one of claims 1-2, characterized in that, The rotor of the regulating motor (7, 8) is detected as the rotational motion of the rotor in each case by the rotation of the defined rotary portion during the adjustment of the positioning unit (2).

7. The method according to claim 6, characterized in that, The second provision is that after the positioning unit (2) is stopped to reverse the direction, the positioning unit (2) is further adjusted according to a predetermined first number of rotational movements of the rotor.

8. The method according to any one of claims 1-2, characterized in that, The first provision of the definition is that the positioning unit (2) is adjusted to the mechanical adjustment stop (20, 21, 22, 23).

9. The method according to claim 6, characterized in that, The first provision of the definition is that, after reaching the virtual adjustment stops (30, 31), the positioning unit (2) is further adjusted according to a predetermined second number of rotational movements of the rotor.

10. The method according to claim 9, characterized in that, The first number of rotational motions of the rotor is equal to the second number of rotational motions of the rotor.

11. The method according to any one of claims 1-2, characterized in that, During the adjustment of the positioning unit (2), the load of the adjusting motor (7, 8) is detected and evaluated, wherein when a predetermined threshold for the load of the adjusting motor (7, 8) is exceeded, it is identified that the positioning unit (2) has reached the mechanical adjusting stop (20, 21, 22, 23).

12. The method according to claim 9, characterized in that, The method is performed m times as specified below: after reaching the virtual adjustment stop (30, 31), the positioning unit (2) is further adjusted according to a predetermined second number of rotational movements of the rotor; And each (m+1)th time is performed as follows: the positioning unit (2) is adjusted to the mechanical adjustment stop (20, 21, 22, 23); Where m is a positive integer.

13. An electrically adjustable steering column (1) for a motor vehicle, said electrically adjustable steering column (1) comprising: The support unit (4) and the positioning unit (2) are held in an adjustable manner by the support unit (4); The adjustment device (5, 6) has an adjustment motor (7, 8) designed to adjust the positioning unit (2) relative to the support unit (4); mechanical adjustment stops (20, 21, 22, 23) mechanically restricting the adjustment of the positioning unit (2) in a first adjustment direction (40); and a control unit (9) designed to enable the adjustment motor (7, 8), wherein a virtual adjustment stop (30, 31) is defined upstream of the mechanical adjustment stops (20, 21, 22, 23) relative to the first adjustment direction (40), characterized in that the steering column (1) is designed to adjust the positioning unit (2) according to any one of claims 1 to 12.

14. The steering column (1) according to claim 13, characterized in that... A position detection unit (90) is designed to detect the position of the positioning unit (2) relative to the support unit (4), wherein the position detection unit (90) is communicatively connected to the control unit (9).

15. The steering column (1) according to claim 13 or claim 14, characterized in that... Sensor units (75, 76) are designed to detect rotational motion of the rotor of the regulating motor (7, 8) through a defined rotating portion in each case during adjustment of the positioning unit (2), wherein the sensor units (75, 76) are communicatively connected to the control unit (9).

16. The steering column (1) according to claim 15, characterized in that... A counter, designed to count the number of rotational movements of the rotor, wherein the counter is communicatively connected to the control unit (9).

17. The steering column (1) according to any one of claims 13 to 14, characterized in that... A motor load detection unit is designed to detect the load of the regulating motor (7, 8) during the adjustment of the positioning unit (2) and to evaluate the load of the regulating motor with respect to exceeding a predetermined threshold for the load of the regulating motor (7, 8), wherein the motor load detection unit is communicatively connected to the control unit (9).

Images