STEERING COLUMN FOR A MOTOR VEHICLE

Description

State of the art

[0001] The present invention relates to a steering column for a motor vehicle for stowing and unstowage, comprising an actuating unit in which a steering spindle is rotatably mounted and which is adjustably held by a support unit, an adjusting device for adjusting the actuating unit relative to the support unit, and a position detection device comprising a first sensor unit for detecting the position of the actuating unit relative to the support unit. Furthermore, the present invention relates to a method for adjusting a steering column and a method for controlling subsystems of a motor vehicle.

[0002] Adjusting the actuator unit is understood as moving or relocating the actuator unit. Adjusting the actuator unit corresponds to adjusting the position of the steering spindle along the adjustment direction of the adjustment device. The actuator unit is held adjustably by the support unit. In other words, the actuator unit is adjustably mounted on the support unit.

[0003] Steering columns for motor vehicles have a steering spindle. At the rear end in the direction of travel, closest to the driver, there is a steering wheel for the driver to initiate steering commands. This end is referred to as the steering wheel end of the steering spindle. The steering spindle is mounted so that it can rotate about its longitudinal axis in a casing unit or in an actuating unit accommodated in the casing unit. The casing unit is carried by a support unit that can be attached to the vehicle body. Because the actuating unit is accommodated in a casing unit connected to the support unit, also referred to as a guide box or box swing arm, so that it can be telescopically displaced in the direction of the longitudinal axis, it can be adjusted longitudinally. Height adjustment can be achieved by pivoting the actuating unit or a casing unit receiving it on the support unit. The adjustment of the actuating unit in the longitudinal or vertical directions is possible.The height adjustment allows for the adjustment of an ergonomically optimal steering wheel position relative to the driver's operating position, also known as the driving or operating position, in which manual steering intervention is possible. The longitudinal and height adjustment is also important for optimizing the driver's view of the display / instrument panel or the vehicle's dashboard.

[0004] The longitudinal and height adjustment of steering columns can be achieved using at least one electric actuator. Such steering columns are referred to as electrically adjustable steering columns (EVLS).

[0005] Electrically adjustable steering columns are particularly important for future, highly automated motor vehicles that can be controlled or driven both manually by a human driver and autonomously by an intelligent driving system. To control the vehicle manually, the steering column must be placed in a so-called unloading state. To control the vehicle autonomously, the steering column can be placed in a so-called stowed state. In this respect, such electrically adjustable steering columns are also referred to as stowable steering columns.

[0006] The deflation state of a lockable, electrically adjustable steering column corresponds to that of a conventional, electrically adjustable steering column. This means that the steering column is adjusted for both length and height in such a way that the steering spindle, and thus the steering wheel, is positioned within the cockpit, driver's cab, or passenger compartment for steering command input.

[0007] When stowed, an electrically adjustable steering column that can be stored and unfolded is adjusted for length and height in such a way that the steering spindle and thus the steering wheel are positioned outside the cockpit or driver's cab or passenger compartment, in any case out of reach of the human driver, and within the dashboard or engine compartment. By moving the steering column into the dashboard, additional space is created for the driver in the cockpit or driver's cab or passenger compartment. This gives the driver the opportunity to devote themselves to activities other than steering or driving while driving. They could adjust their seat to a comfortable position for relaxing, an upright position for reading, or a horizontal position for resting or sleeping. They could also adjust their seat towards the interior of the vehicle to face other vehicle occupants.

[0008] For reliable operation of electrically adjustable steering columns that can be stored and unstored, it is necessary to reliably record the position or spatial location of the steering column in all its adjustment directions.

[0009] A steering column with position detection is known from US 2018 / 0086378 A1. This proposes an electric generator with an input shaft and a steering spindle kinematically coupled to the input shaft, with the steering spindle being movable relative to the electric generator. The electric generator converts the kinetic energy generated by the movement of the steering spindle into electrical energy, which allows the position of the steering spindle to be determined.

[0010] The disadvantage of such a steering column is its relatively complex and therefore maintenance-intensive design. Since it is a relative measurement method, meaning the change in the steering spindle position is recorded and then compared to a predefined reference value, this can also lead to inaccurate measured values ​​in certain situations.

[0011] Furthermore, it is known from the prior art to detect the position of the steering spindle using a Hall sensor by counting so-called Hall counts, whereby a conclusion can be drawn about the change in the steering spindle position from the number of Hall counts. This is a relative measurement method. The problem with this is that if Hall counts are not counted - for whatever reason - a position is detected that is incorrect or deviates so much from the actual position that a sufficiently accurate determination of the position is no longer possible. Although the effect of a few individual Hall counts not being counted on measurement accuracy can sometimes be negligible, there is a risk of the detected steering spindle position drifting away from the actual steering spindle position, namely that the non-counting of individual Hall counts accumulates over the course of operation.

[0012] Furthermore, DE 10 2004 044 472 A1 discloses an adjustable steering column of a motor vehicle with a magnetic sensor system for monitoring the position of the steering column. A first point-shaped element of the magnetic sensor system is fixedly mounted, and a cooperating second element of the magnetic sensor system, which extends over the adjustment range on the adjustable part of the steering column, is arranged on the actuating unit. As long as the point-shaped first element is within the range of the second element, a sensor signal is generated that indicates adjustment within a permissible range. The ends of the second element therefore represent end stops.

[0013] DE 101 44 476 A1 also discloses an electromechanically adjustable steering column. The respective position of the steering column for evaluating relative movement is determined by a sensor, such as a potentiometer. Furthermore, limit switches are provided that can be activated when the vehicle engine is switched off to perform self-adjustment.

[0014] Furthermore, US 2016 / 0375927 A1 discloses a steering column that can be adjusted between a stowed position and an operating position. This allows an airbag to be deployed differently, depending on whether the steering column is in the operating position or the stowed position.

[0015] In light of the disadvantages of the known steering columns explained above, the object of the present invention is to provide a steering column with a position detection device which has a simple and robust construction and whose operation is reliable and safe. Description of the invention

[0016] The object underlying the present invention is achieved by a steering column for a motor vehicle having the features of claim 1 and by the respective methods having the features of claims 8 and 14. Advantageous further developments emerge from the subclaims.

[0017] A steering column for a motor vehicle is proposed, comprising an actuating unit in which a steering spindle is rotatably mounted and which is adjustably held by a support unit, an adjusting device for adjusting the actuating unit relative to the support unit and a position detecting device which comprises a first sensor unit for detecting the position of the actuating unit relative to the support unit.

[0018] According to the invention, the position detection device comprises a second sensor unit for detecting a state when the actuating unit is in a predetermined position relative to the support unit. The predetermined position can be set or stored as a reference value. This can be done, for example, during the installation of the second sensor unit on the steering column. The reference value can be determined, in particular, by a reference run of the steering spindle for the purpose of data collection at or into the adjustment position corresponding to the reference value before the steering column is put into normal operation. The predetermined position is a position that deviates from the positions defined by the end stops of the actuating unit.

[0019] The support unit can be attached to a vehicle body. Furthermore, a casing unit can be attached to the support unit so that it can pivot about a pivot axis. The actuating unit can be accommodated in the casing unit.

[0020] The steering column may further comprise a control unit, also referred to as an "electrical control unit" or ECU, which controls the adjustment device.

[0021] The first sensor unit serves to detect, in particular relative, the position of the actuator unit relative to the support unit and thus to detect, in particular relative, the position of the steering spindle relative to the support unit. The first sensor unit can be configured to generate a first sensor signal, for example based on Hall counts, and to transmit it to the control unit.

[0022] The control unit can be configured to receive and evaluate one or more input signals, in particular the first sensor signal, and then execute definable actions, in particular to generate one or more output signals and transmit them to the adjustment device. The second sensor unit serves to detect, in particular absolutely, the predetermined position of the actuating unit relative to the support unit and thus to detect, in particular absolutely, the predetermined position of the steering spindle relative to the support unit.

[0023] Advantageously, the second sensor unit is designed such that the predetermined position can be set at any position along the entire adjustment range of the actuating unit relative to the support unit. In particular, multiple positions or a position section can also be defined as the predetermined position. The predetermined position advantageously lies in a range around a central adjustment position of the actuating unit relative to the support unit. In particular, the predetermined position is set such that a transition from the storage area to the operating area and vice versa can be reliably detected.

[0024] The second sensor unit can comprise a transmitter or encoder module and a receiver module, wherein the transmitter module and the receiver module are movable relative to one another. The second sensor unit can be configured to generate a second sensor signal, for example a binary-value, discrete-value, quasi-continuous-value, or continuous-value signal, and to transmit it to a control unit. A binary-value second sensor signal can represent the presence or absence of the transmitter module to the receiver module, or vice versa. A binary-value second sensor signal has a jump or a pulse as soon as the relative distance between the transmitter module and the receiver module reaches, falls below, or exceeds a specified threshold value. A discrete-value, quasi-continuous-value, or continuous-value second sensor signal can represent the distance or the distance orrepresent the distance between the transmitter module and the receiver module. The second sensor signal is also called the revision signal. This signal is then transmitted to the control unit or detected by it when the actuator is in the predetermined position.

[0025] For the purposes of the invention, the term "transmitter module" is not limited to the fact that it transmits a signal. For example, the transmitter module can be designed as a permanent magnet or as a metallic body.

[0026] The predetermined position can be understood as a single position or a range of positions.

[0027] By appropriately positioning the transmitter module relative to the receiver module, which can vary from vehicle to vehicle due to design differences, a stimulus in the form of a jump or pulse in the second sensor signal is generated at at least one specific adjustment position, particularly during each stowing and unstowage of the steering column. The stimulus in the second sensor signal can be used as an indicator or a triggering event.

[0028] During the adjustment of the actuating unit and the steering spindle mounted therein, the transmitter module and the receiver module move relative to one another. The transmitter module and the receiver module are positioned relative to one another, i.e., they are each arranged on the steering column, such that the modules are directly opposite one another at least in a specific adjustment position, which in particular deviates from the end positions. In precisely this adjustment position, the relative distance between the transmitter module and the receiver module reaches, falls below, or exceeds a previously defined threshold value - depending on the stored query or logic - so that a stimulus is generated in the second sensor signal. The threshold value is defined before commissioning and can be entered as an adjustable setting, for example in the control unit, or as an unchangeable or hard-coded setting, for example in the control unit.

[0029] The position detection device of the steering column according to the invention can effectively prevent collisions between the steering column or its components and trim elements within the cockpit. Potential or impending collisions can be detected early and averted by initiating countermeasures.

[0030] For vehicle safety, it is important to detect "illegal" or potentially dangerous vehicle conditions early on. The position detection device of the steering column according to the invention also serves to detect unintentional stowing during manual driving. Furthermore, it is important that the correct airbag system is deployed in the event of an accident or crash. Due to its ability to distinguish between different steering column conditions, the position detection device of the steering column according to the invention can trigger the correct airbag system to optimally protect the driver. For example, in an unstowed state, in which the driver is driving the vehicle himself, an airbag in the steering wheel can be deployed in the event of a crash. In a stowed state, in which the vehicle is autonomously controlled, the airbag in the steering wheel can remain undeployed and an airbag in the instrument panel can be deployed in the event of a crash.

[0031] The first sensor unit can be integrated into the adjustment device or arranged outside the adjustment device. The first sensor unit can be designed to continuously detect the adjustment, i.e., during the entire operating time of the steering column or at least for the entire duration of the adjustment.

[0032] The control unit can be integrated into the shell unit or located outside the shell unit.

[0033] The control unit can be configured to correct the sensor values ​​of the first sensor unit based on the second sensor signal. Specifically, the sensor values ​​of the first sensor unit can be compared with a validation value as soon as the spatial condition that leads to the generation of a stimulus in the second sensor signal is met. The validation value can be a sensor value of the second, absolutely operating sensor unit, which is recorded when the spatial condition is met, or a predefined reference value.

[0034] The control unit can also be configured to control, in particular activate and deactivate, various subsystems of the motor vehicle based on the second sensor signal. This allows for differentiation of steering column states and allows for the definition of circuit logic according to which certain subsystems of the vehicle are activated or deactivated only when a specific spatial condition is met.

[0035] For example, various airbag systems can be activated or deactivated in this way. If the steering column is in one of the possible deflation states to allow the driver to manually control the vehicle, the airbag system in the steering wheel must be activated and the airbag system in the dashboard, located behind the steering wheel from the driver's perspective, deactivated to provide optimal driver protection.

[0036] However, if the steering column is in one of the possible stowed states in order to provide the driver with additional space in the driver's cabin or passenger compartment at his or her free disposal during autonomous driving of the vehicle, the airbag system in the dashboard must necessarily be activated and the airbag system in the stowed steering wheel must be deactivated in order to optimally protect the driver.

[0037] An advantageous embodiment results in the first sensor unit and / or the second sensor unit being designed to operate contactlessly, in particular magnetically, inductively, optically, or similarly. In other words, the sensor units are designed to operate contactlessly. This reduces mechanical wear on the sensor unit and thus improves its durability and longevity. Sensor units designed to operate magnetically or inductively are particularly preferred, as they are relatively less prone to failure and are characterized by a simple and robust design.

[0038] Furthermore, it is advantageous if the sensor units are each designed to use the same measuring principles. This reduces the complexity of the steering column in terms of manufacturing, maintenance, and construction. Alternatively, the sensor units can also be designed to use different measuring principles. This can increase safety and significantly reduce the risk of complete failure of the position detection system.

[0039] Furthermore, the position detection device can comprise a third sensor unit for detecting a second state when the actuating unit is in a predetermined second position relative to the support unit. The second position is different from the position of the second sensor unit. In other words: the second position is a position that deviates from the position of the second sensor unit. The predetermined second position can be set or stored as a reference value. The reference value can be determined in particular by a reference run of the steering spindle for the purpose of data collection to or into the second adjustment position corresponding to the reference value before the steering column is put into normal operation. This can take place, for example, during assembly of the steering column or during assembly of the steering column in the motor vehicle.

[0040] Analogous to the second sensor unit, the third sensor unit serves to detect, in particular absolutely, the position of the actuating unit relative to the support unit and thus to detect, in particular absolutely, the position of the steering spindle relative to the support unit. The third sensor unit can comprise a transmitter or encoder module and a receiver module, wherein the transmitter module and the receiver module are movable relative to one another. The third sensor unit can be configured to generate a third sensor signal, for example a binary, discrete, quasi-continuous, or continuous-value signal, and to transmit it to a control unit. A binary third sensor signal can represent the presence or absence of the transmitter module to the receiver module, or vice versa.A binary-valued third sensor signal exhibits a jump or a pulse as soon as the relative distance between the transmitter module and the receiver module reaches, falls below, or exceeds a specified threshold. A discrete-value, quasi-continuous-value, or continuous-value third sensor signal can represent the distance between the transmitter module and the receiver module. The third sensor signal is also referred to as a second revision signal or simply a revision signal.

[0041] In an advantageous development, the receiver module can be designed as an inductive sensor. Alternatively, the receiver module can also be designed as a magnetic switch.

[0042] The terms transmitter module and encoder module can be used interchangeably. The transmitter module or encoder module can be designed as an active or passive transmitter module. The passive transmitter module can be designed, for example, as a permanent magnet or as a ferromagnetic element.

[0043] Furthermore, the adjustment device can be a longitudinal adjustment device and / or a height adjustment device. In other words, the actuating unit can be adjustable relative to the support unit in a longitudinal adjustment direction and / or a height adjustment direction. Longitudinal and height adjustment of the actuating unit and the steering spindle mounted therein is suitable for achieving an ergonomic adjustment of the steering wheel position relative to the driver.

[0044] The receiver module of the second sensor unit and / or the third sensor unit can be designed to be stationary with respect to the adjustment direction of the position detection device, and the transmitter module can be designed to be movable relative to the receiver module. The transmitter module can thus be moved past the receiver module. Alternatively, the transmitter or encoder module of the second sensor unit and / or the third sensor unit can be designed to be stationary with respect to the adjustment direction of the position detection device, and the receiver module can be designed to be movable relative to the transmitter module. The receiver module can thus be moved past the transmitter module. In both alternatives, one module is stationary with respect to the adjustment direction in question, while the other module is movable or displaceable along this adjustment direction.In other words, when adjusting in the corresponding adjustment direction, the transmitter module is displaced relative to the receiver module.

[0045] Furthermore, the transmitter module and the receiver module can advantageously be positioned relative to one another in such a way that the relative distance between the transmitter module and the receiver module reaches, falls below or exceeds the specified threshold value during each stowing and unstacking process or during each stowing and unstacking process.

[0046] In a further advantageous manner, the transmitter module and the receiver module can be positioned relative to one another such that the relative distance between the transmitter module and the receiver module is as small or minimal as possible. This makes it possible to generate a particularly good quality of the inspection signal. Particularly preferably, the distance between the transmitter module and the receiver module is minimal in the predetermined position. In other words, the distance between the transmitter module and the receiver module is smaller in the predetermined position than in any other position that the actuating unit can assume relative to the support unit.

[0047] In accordance with the invention, a method is further proposed for adjusting the steering column according to the invention. The method comprises the steps of adjusting the actuating unit, in particular the position of the actuating unit, in particular the position of the steering spindle, relative to the support unit by means of the adjusting device, so that the steering spindle of the steering column is adjusted along the corresponding adjustment direction; detecting the position of the actuating unit by the first sensor unit, in particular by means of a relative measuring method; detecting a state by the second sensor unit when the actuating unit is in a predetermined position relative to the support unit.

[0048] Advantageously, the method comprises the following further steps: comparing the position detected by the first sensor unit with the predetermined position of the actuator when the second sensor unit detects the condition; detecting a malfunction of one of the sensor units when the deviation determined by the comparison exceeds a specified threshold. The threshold can be set before commissioning and can be entered as a variable setting of the control unit or can be entered as an unchangeable or hard-coded setting of the control unit.

[0049] This detection prevents the detection of an incorrect sensor value, i.e., an incorrect position that remains undetected as such, resulting in a "false positive." This can be particularly the case with systematic errors or drift errors over the operating life of the steering column. This allows the respective position of the steering spindle to be reliably detected in both the longitudinal and vertical adjustment directions.

[0050] In a further advantageous manner, the method comprises the following further steps: detecting a second state by a third sensor unit when the actuating unit is in the predetermined second position relative to the support unit; comparing the position detected by the first sensor unit with the predetermined second position of the actuating unit when the third sensor unit detects the second state; detecting a malfunction of one of the sensor units when the deviation determined by the comparison exceeds a specified threshold value. The third sensor unit makes it possible to check the result of the second sensor unit. In this way, a type of redundancy is created which leads to malfunctions of the sensor units being detected more reliably. This could be important for product development according to the ASIL-D classification.

[0051] The method preferably comprises the following further step: correcting the position of the first sensor unit when the malfunction is detected. For this purpose, the sensor value of the first sensor unit is preferably replaced by the sensor value of the second sensor unit, i.e. by the corresponding previously known position. The previously known position is a reference value that can be determined by a reference run of the steering spindle for data collection at or into the adjustment position corresponding to the reference value before the steering column is put into normal operation. Alternatively, the reference value can also be a position of the actuating unit measured by the second sensor unit. Incorrect sensor values ​​or positions are thus overwritten. The correction of the sensor values ​​of the first sensor unit that deviate from the true sensor value or measured value thus represents a contribution to improving the reliability of the steering column.

[0052] In a further preferred manner, the method comprises the following further step: slowing down or stopping the adjustment or adjustment movement of the actuating unit relative to the support unit. This can occur, for example, if a deviation between the position determined by the first sensor unit and the position determined by the second sensor unit has exceeded a predetermined maximum deviation of the positions. Thus, a comparison of the two positions determined by the sensor units is carried out. If these deviate too significantly from one another, the adjustment is slowed down or stopped.In other words, the slowing down and / or stopping of the adjustment occurs when the actuating unit is in the predetermined position and the position determined by the first sensor unit deviates from this predetermined position to such an extent that the positions determined by the two sensor units exceed a predetermined maximum deviation from each other. Particularly preferably, the maximum permissible deviation is greater than 0.5 mm, most preferably greater than 1 mm.

[0053] Advantageously, the comparing method step comprises the steps of detecting a sensor value by the second sensor unit or third sensor unit using an absolute measurement method; determining the deviation between the current sensor value of the first sensor unit and the sensor value of the second sensor unit or third sensor unit. This creates redundancy, which further increases the reliability of the steering column.

[0054] Alternatively, the comparison method step comprises the steps of determining the deviation between the current sensor value of the first sensor unit and a specified reference sensor value of the second sensor unit or third sensor unit; storing the reference value as the sensor value of the second sensor unit or third sensor unit. The reference value can be determined by a reference movement of the steering spindle for data collection at or into the adjustment position corresponding to the reference value before the steering column is put into operation as intended. This eliminates the need for the second sensor unit to explicitly record a sensor value, further simplifying the design.

[0055] Furthermore, a method is proposed according to the invention for controlling, in particular for activating and deactivating, subsystems of a motor vehicle, in particular airbag systems, using the steering column according to the invention. The method comprises the steps of adjusting the actuating unit, in particular the position of the steering spindle of the steering column, relative to the support unit by means of the adjusting device; generating a status signal of the steering column as a function of the adjustment of the actuating unit, in particular the position of the steering spindle, during the adjustment, wherein the revision signal is a switching, jump, or step signal or a pulse or shock signal; detecting a first status of the steering column when the status signal assumes a first value, falls below or exceeds a first value, or detecting at least one further status of the steering column when the status signal assumes at least one further value, falls below or exceeds a first value.Alternatively, this step may be characterized by detecting a first state of the steering column before the state signal has a pulse, or detecting at least one further state after the state signal has at least one pulse; controlling the subsystem corresponding to the detected state according to a specification.

[0056] The definition corresponds to an assignment from which it can be derived which subsystem is to be controlled in which detected state. The definition is defined before commissioning and can be entered as an adjustable setting of the control unit or as an unchangeable or hard-coded setting of the control unit.

[0057] This allows the driver to be optimally protected by the selected airbag systems, both when the airbags are stowed and when the airbags are removed. The selection—that is, the targeted activation and deactivation—of individual airbag systems from a multitude of different airbag systems arranged or installed in the vehicle structure surrounding the passenger compartment depends on the respective steering column status, i.e., whether the steering spindle is stowed or unstowed. Description of the drawing

[0058] Advantageous embodiments of the invention are explained in more detail below with reference to the drawings. Figure 1 shows an embodiment of the steering column according to the invention in a perspective view, Figure 2 shows the steering column from Figure 1 in a perspective detail, Figure 3 the steering column from Figure 1 in a side view, Figure 4 the steering column Figure 1in a side view, Figure 5 the steering column from Figure 1 in a side view, Figure 6the steering column from Figure 1 in a side view, Figure 7 the steering column from Figure 1 in a highly simplified, schematic side view with a diagram of possible signals, and Figure 8 shows an alternative embodiment of the steering column according to the invention in a perspective view. Embodiments of the invention

[0059] In the various figures, identical parts are always provided with the same reference symbols and are therefore usually named or mentioned only once.

[0060] Figure 1 shows an embodiment of the steering column 1 according to the invention in a perspective view obliquely from the rear in the direction of vehicle travel.

[0061] The steering column 1 comprises a support unit 2 and a casing unit 4 pivotably mounted thereon about a pivot axis 3. The steering column 1 can be attached to a vehicle body (not shown in the figures) via the support unit 2. For this purpose, the support unit 2, designed as a two-part console, has through-openings 5 ​​for receiving fastening means (also not shown in the figures). The support unit 2 serves to pivotably suspend the casing unit 4 from the vehicle body.

[0062] An actuating unit 6 is accommodated in the casing unit 4. The actuating unit 6 is movably connected to the casing unit 4, i.e., the actuating unit 6 can be telescopically displaced relative to the casing unit 4 by being inserted into and withdrawn from the casing unit 4. The actuating unit 6 is designed as a tubular body. The tubular body of the actuating unit 6 is arranged coaxially in the casing unit 4 at the end facing away from the driver, namely, it is mounted therein for axial displacement.

[0063] The actuating unit 6 comprises a steering spindle 7. The steering spindle 7 is rotatably mounted in the actuating unit 6. Thus, the steering spindle 7 is also rotatably mounted in the casing unit 4, since the actuating unit 6 is accommodated in the casing unit 4. Thus, the steering spindle 7 is mounted in the casing unit 4 with the actuating unit 6 interposed.

[0064] It is also conceivable and possible that the steering spindle 7 is mounted directly in the casing unit 4. The end of the steering spindle 7 facing the driver ( Figure 1 The steering wheel end (right-hand side), which is referred to as the steering wheel end, has an external toothing (not shown in the figures) for receiving an internally toothed hub of a steering wheel (also not shown in the figures). As an alternative to the external toothing or internal toothing, other positive-locking profiles can also be used to torque-couple the steering spindle 7 to the steering wheel.

[0065] Furthermore, the steering column 1 includes a control unit 8 for evaluating a service signal. The control unit 8 is firmly screwed to the casing unit 3.

[0066] Furthermore, the steering column 1 comprises an adjusting device 9 designed as a longitudinal adjustment device for the longitudinal adjustment of the steering spindle 7, namely for the translational movement of the actuating unit 6 and thus of the steering spindle 7 along the adjustment direction of the adjusting device 9, namely along the steering spindle axis L, relative to the support unit 2 and relative to the casing unit 4. In other words: From the driver's perspective, this involves an adjustment of the steering wheel position in the "forward or backward" direction.

[0067] In addition, the steering column 1 comprises an adjustment device 10 designed as a height adjustment device for adjusting the height of the steering spindle 7, namely for pivoting the casing unit 4 together with the actuating unit 6 and thus the steering spindle 7 along the adjustment direction of the adjustment device 10, namely about the pivot axis 3, relative to the support unit 2. From the driver's perspective, this involves adjusting the steering wheel position in the "upward or downward" direction.

[0068] Figure 2 shows the steering column 1 from Figure 1 in a perspective detailed view from the front in the direction of vehicle travel.

[0069] The steering column 1 further comprises a position detection device 11 and a position detection device 12. The position detection device 11 is assigned to the adjustment device 9 designed as a longitudinal adjustment device and serves to detect the position of the steering spindle 7 along the adjustment direction of the adjustment device 9, namely along the longitudinal direction of the steering column 1. The position detection device 12 is assigned to the adjustment device 10 designed as a height adjustment device and serves to detect the position of the steering spindle 7 along the adjustment direction of the adjustment device 10, namely along the height direction of the steering column 1.

[0070] The adjustment device 9, designed as a longitudinal adjustment device, has an adjustment drive 13. The adjustment drive 13 comprises an electric servomotor or electric motor 14, a spindle nut with an internal thread, and a threaded spindle 15 with an external thread, wherein the spindle nut and the threaded spindle 15 are threadably engaged with one another. The adjustment drive 13 drives the spindle nut in rotation about its axis of rotation. Due to the threaded engagement of the spindle nut and the threaded spindle 15, the rotation of the spindle nut causes a translation of the threaded spindle 15 along its longitudinal axis. The threaded spindle 15 is thus a plunger spindle. The longitudinal axis of the threaded spindle 15 runs parallel to the steering spindle axis L. The threaded spindle 15 is connected at its end facing the driver via a linkage lever 16 ( Figure 1) is connected to the actuating unit 6, so that a translation of the threaded spindle 15 causes a translation or an axial displacement of the actuating unit 6 along the steering spindle axis L.

[0071] An end stop 17 is located at the end of the threaded spindle 15 facing away from the driver. The end stop 17 serves as a mechanical stop or (end) stop for the movement of the threaded spindle 15 along its longitudinal axis.

[0072] The position detection device 11 comprises a first sensor unit 18 and a second sensor unit 19.

[0073] The first sensor unit 18 is integrated into the adjustment drive 13. Due to the kinematic connection realized via the linkage lever 16, the translational movement of the threaded spindle 15 along its longitudinal axis corresponds to the translational movement of the steering spindle 7 along the steering spindle axis L. The first sensor unit 18 detects the longitudinal adjustment of the steering spindle 7 using a relative or incremental measuring method. This means that the first sensor unit 18 detects the change in a measured variable, namely the change in length or the change in the longitudinal adjustment of the steering spindle 7. The detected change in the measured variable is then related to a known reference value to determine the sensor value. The sensor value of the first sensor unit 18 corresponds to this reference value, taking the detected change in the measured variable into account accordingly.The first sensor unit 18 continuously detects the longitudinal adjustment of the steering spindle 7, i.e. during the entire operating time of the steering column or at least during the entire duration of the adjustment.

[0074] The second sensor unit 19 detects the longitudinal adjustment of the steering spindle 7 using an absolute measurement method. This means that the second sensor unit 19 detects a measured variable as such, namely the position or position range or the length or the longitudinal adjustment of the steering spindle 7. Reference to a reference value is not required and does not occur. Rather, the sensor value of the second sensor unit 19 corresponds directly to the detected measured variable. The position of the steering spindle 7 detected by the second sensor unit 19 can advantageously lie anywhere over the entire adjustment range of the steering spindle 7. In particular, the position of the steering spindle is detected where a transition from the stowage area to the operating area or a transition from the operating area to the stowage area occurs. This improves the control and deployment of the airbag with the best possible protective effect for a driver.

[0075] The second sensor unit 19 has a transmitter / transmitter module 20 and a receiver module 21. The transmitter module 20 and the receiver module 21 are movable relative to each other. The receiver module 21 is fixedly connected to the control unit 8 with respect to the adjustment direction of the position detection device 11, whereas the transmitter module 20 is connected to the end of the threaded spindle 15 facing away from the driver. The transmitter module 20 is movable relative to the fixed receiver module 21, since the threaded spindle 15 can be displaced axially along its longitudinal axis by the adjustment drive 13.

[0076] The second sensor unit 19 detects the longitudinal adjustment of the steering spindle 7 precisely when the spatial distance between the transmitter module 20 and the receiver module 21 falls below the specified threshold. Thus, the second sensor unit 19 detects the longitudinal adjustment of the steering spindle 7 as soon as the steering spindle 7 either assumes or passes through the center position.

[0077] The adjustment device 10, designed as a height adjustment device, has an adjustment drive 22. The adjustment drive 22 causes the casing unit 4 to pivot about the pivot axis 3 ( Figure 1 ) and thus adjusts the height of the steering column 1.

[0078] In an analogous manner to the position detection device 11, the position detection device 12 comprises a first sensor unit 23 and a second sensor unit 24.

[0079] The first sensor unit 23 is integrated into the adjustment drive 22. It detects the height adjustment of the steering spindle 7 using a relative or incremental measurement method. The first sensor unit 23 detects the height adjustment of the steering spindle 7 continuously, i.e., throughout the entire operating time. With regard to the first sensor unit 23 and its relative measurement method, as well as its continuous detection, the above statements regarding the first sensor unit 18, which detects the longitudinal adjustment, apply analogously.

[0080] The second sensor unit 24 detects the height adjustment of the steering spindle 7 using an absolute measurement method. The second sensor unit 24 has a transmitter / transmitter module 25 and a receiver module 26. The transmitter module 25 and the receiver module 26 are movable relative to one another. The transmitter module 25 is fixedly connected to the support unit 2 with respect to the adjustment direction of the position detection device 12. The receiver module 26 is movable relative to the fixed transmitter module 25 because the receiver module 26 is fixedly connected to the control unit 8 and the control unit 8 is fixedly connected to the casing unit 4. The casing unit 4 can be pivoted about the pivot axis 3 relative to the support unit 2 by the adjustment device 10.

[0081] The transmitter module 25 and the receiver module 26 of the second sensor unit 24 of the adjustment device 10 are arranged relative to one another such that, when the steering spindle 7 is in its center position with respect to the height adjustment—position between a minimum and a maximum adjustment position—or passes through this position, the modules 25, 26 are directly opposite one another. In this adjustment position of the steering spindle 7, the spatial distance, i.e., the relative distance, between the transmitter module 25 and the receiver module 26 falls below a previously determined or predefined threshold value. It should also be noted again at this point that the transmitter module 25 is not limited to actively transmitting a signal. This transmitter module 25 can, for example, be formed by a permanent magnet or a ferromagnetic element.For example, it is also conceivable and possible that the transmitter module 25 and the support unit 2 are formed as a one-piece integral component.

[0082] The second sensor unit 24 detects the height adjustment of the steering spindle 7 precisely when the spatial distance between the transmitter module 25 and the receiver module 26 falls below the specified threshold. Thus, the second sensor unit 24 detects the height adjustment of the steering spindle 7 as soon as the steering spindle 7 either assumes or passes through the center position. The center position thus corresponds to a predetermined position between the minimum and maximum adjustment positions.

[0083] With regard to the second sensor unit 24 and its absolute measuring method as well as its conditional detection, the above statements apply analogously to the second sensor unit 19 detecting the longitudinal adjustment.

[0084] The control unit 8 is configured to correct the sensor values ​​of the first sensor unit 18, 23 based on the revision signal. It is also configured to activate and deactivate various airbag systems of the motor vehicle depending on the situation based on the revision signal.

[0085] The first sensor unit 18 of the position detection device 11, the second sensor unit 19 of the position detection device 11, the first sensor unit 23 of the position detection device 12 and the second sensor unit 24 of the position detection device 12 are each designed as magnetic sensors.

[0086] Figure 3 shows the steering column 1 from Figure 1in a side view. The steering spindle 7 is fully retracted with respect to the longitudinal adjustment. In this state, the length of the steering column 1—measured from the end of the steering column 1 facing the driver along the steering spindle axis L to the end of the steering column 1 facing away from the driver—is reduced to its minimum. This state could correspond to a stowed state of the steering column 1, in which the steering column 1 is "stowed" toward the dashboard from the driver's perspective, i.e., relocated or telescoped in.

[0087] While the steering column 1 is in its stowed state, the motor vehicle could be controlled autonomously. With the steering column 1 stowed, the driver would have additional space in the driver's cab or passenger compartment at their disposal. The additional space gained by stowing the steering column 1 could, for example, be used to move the driver's seat to a horizontal position, allowing the driver to rest during the autonomous driving of the motor vehicle.

[0088] With respect to the height adjustment, the steering spindle 7 is in its center position. This means that the steering spindle 7, and thus the steering column 1, is in the center position between a highest and a lowest adjustment position in its height adjustment direction. In the center position in the height adjustment direction, the transmitter module 25 and the receiver module 26 are directly opposite each other, i.e., they are at the same height.

[0089] Figure 4shows the steering column 1 from Figure 1 in a side view. Compared to the Figure 3 In the adjustment position shown, the steering spindle 7 is in a slightly extended position in the direction of longitudinal adjustment from the center position. This state could correspond to a possible "unblocking" state of the steering column 1, in which the steering column 1 is "unblocked" from the driver's perspective, i.e., moved or telescoped out. As shown in Figure 3 the steering spindle 7 is in its central position with regard to the height adjustment.

[0090] Figure 5 shows the steering column 1 from Figure 1in a side view. The steering spindle 7 is fully extended with respect to the longitudinal adjustment. The end of the threaded spindle 15 facing away from the driver, and thus the transmitter module 20 of the second sensor unit 19 of the position detection device 11, are not visible in this view. The end stop arranged at the end of the threaded spindle 15 facing away from the driver abuts against a counter surface of the adjustment drive 13 or is at least close to such surface contact. In this state, the length of the steering column 1 is increased to its maximum. This state could correspond to the greatest possible unblocking state of the steering column 1 and is also referred to as the fully extended state.

[0091] When the steering column 1 is in a clear state, the driver can conveniently input steering commands for the motor vehicle by turning the steering wheel. While the steering column 1 is in one of its clear states, the motor vehicle could thus be steered manually by the driver. As shown in Figure 3 the steering column 1 is in its central position with regard to height adjustment.

[0092] Figure 6 shows the steering column 1 from Figure 1 in a side view. The steering column 1 is in a position slightly retracted from the center position in the direction of longitudinal adjustment.

[0093] With respect to height adjustment, steering column 1 is in a lower position. This means that steering column 1 is in a lower adjustment position in its height adjustment direction.

[0094] Figure 7 , above, shows the steering column 1 from Figure 1in a highly simplified, schematic side view. As explained above, the steering column 1 comprises the support unit 2, the casing unit 4, which is pivotably attached to the support unit 2 about the pivot axis 3, the control unit 8, and the adjustment device 9. The actuating unit 6, which is telescopic along the steering spindle axis L, is mounted in the casing unit 3. The steering spindle 7 is rotatably mounted in the actuating unit 6.

[0095] The steering column 1 is in its center position in the longitudinal adjustment direction. The transmitter module 20 and the receiver module 21 of the second sensor unit 19 of the position detection device 11 assigned to the adjustment device 9 are arranged in such a way that they are directly opposite each other in the center position, so that the distance between the transmitter module 20 and the receiver module 21 falls below a specified threshold. The receiver module 21 is permanently connected to the control unit 8 and is thus stationary in the longitudinal adjustment direction. The transmitter module 20 is arranged at the end of the threaded spindle 15, which is displaceable along its longitudinal axis, facing away from the driver. Thus, as indicated by the horizontal, double-headed arrow running parallel to the steering spindle axis, the transmitter module 20 is displaceable relative to the fixed receiver module 21.

[0096] The steering column 1 is also in its center position in the height adjustment direction. The transmitter module 25 and the receiver module 26 of the second sensor unit 24 of the position detection device 12 assigned to the adjustment device 10 are arranged such that they are directly opposite each other in the center position, so that the distance between the two modules 25, 26 falls below a specified threshold. The transmitter module 25 is firmly connected to the support unit 2 and is thus stationary in the height adjustment direction.

[0097] The receiver module 26 is attached to the control unit 8. The control unit 8, in turn, is firmly connected to the pivotable casing unit 4. Thus, as indicated by the vertically curved, double-headed arrow running almost perpendicular to the steering spindle axis, the receiver module 26 is pivotable relative to the fixed transmitter module 25.

[0098] Figure 7, below, shows a diagram with two possible embodiments of a signal, namely a revision signal or status signal. The signal S 1 (x) represents a signal value s 1 about the stroke or adjustment range x min ≤×≤x max the threaded spindle 15 and thus the steering spindle 7 in the longitudinal adjustment direction from the fully retracted longitudinal adjustment x min (minimum adjustment position of the steering spindle 7) up to the fully extended longitudinal adjustment xmax (maximum adjustment position of the steering spindle 7). The signal value s 1 represents different states that the steering column 1 can assume during adjustment. In this embodiment, the signal value s 1 two different values, namely s 1,low and s 1 , high , where s 1,low 1,high In general, the signal value s 1 However, other values ​​can be assumed. The longitudinal adjustment x stm ​refers to the relative positioning of the transmitter module 20 to the receiver module 21 precisely when the relative distance between the transmitter module 20 and the receiver module 21 falls below the previously defined threshold during the adjustment, and as a result, a stimulus is generated in the signal. The stimulus, i.e., the information that the distance between the transmitter module 20 and the receiver module 21 has fallen below the previously defined threshold during the adjustment, is modulated as a jump in the signal. The signal S 1 (x) is therefore a switching, jump or step signal.

[0099] The signal S 2 (x) represents an alternative signal value s in an analogous manner 2 about the adjustment range x min ≤x ≤x max in the longitudinal adjustment direction. In contrast to the aforementioned signal, the signal S 2 (x)a pulse or shock signal. Therefore, the stimulus, i.e., the information that the distance between the transmitter module 20 and the receiver module 21 has fallen below the previously defined threshold during the adjustment, is modulated as a shock in the signal.

[0100] For a better overview, the diagram ( Figure 7 , below) compared to the schematic side view ( Figure 7 , above) are aligned laterally so that the adjustment positions x min , x stm and xmax are each correctly placed below the corresponding positions of the transmitter module 20.

[0101] The stimulus and thus the differentiation of states of the steering column 1 makes it possible to control different subsystems of the motor vehicle depending on the respective state.

[0102] Figure 8 shows a steering column 1 in an alternative embodiment, which, in contrast to the steering column of the first embodiment, Figures 1 to 7 a position detection device 11 with an additional third sensor unit 111.

[0103] The first sensor unit 18 is integrated into the adjustment drive 13. Due to the kinematic connection realized via the linkage lever 16, the translational movement of the threaded spindle 15 along its longitudinal axis corresponds to the translational movement of the steering spindle 7 along the steering spindle axis L. The first sensor unit 18 detects the longitudinal adjustment of the steering spindle 7 using a relative or incremental measuring method. This means that the first sensor unit 18 detects the change in a measured variable, namely the change in length or the change in the longitudinal adjustment of the steering spindle 7. The detected change in the measured variable is then related to a known reference value to determine the sensor value. The sensor value of the first sensor unit 18 corresponds to this reference value, taking the detected change in the measured variable into account accordingly.The first sensor unit 18 continuously detects the longitudinal adjustment of the steering spindle 7, i.e. during the entire operating time of the steering column or at least during the entire duration of the adjustment.

[0104] The second sensor unit 19 detects the longitudinal displacement of the steering spindle 7 using an absolute measurement method. This means that the second sensor unit 19 detects a measured variable as such, namely the first predetermined position or the length or the longitudinal displacement of the steering spindle 7. Reference to a reference value is not required and does not occur. Rather, the sensor value of the second sensor unit 19 directly corresponds to the detected measured variable.

[0105] The third sensor unit 111 detects the longitudinal adjustment of the steering spindle 7 using an absolute measurement method. This means that the third sensor unit 19 detects a measured variable as such, namely the second predetermined position or the length or the longitudinal adjustment of the steering spindle 7. The second predetermined position is spaced from the first predetermined position. The third sensor unit 111 comprises a receiver module 210 and a transmitter module, which can also be referred to as a sensor module, and which is identical to the transmitter module 20 of the second sensor unit 19. The third sensor unit 111 is identical in structure and mode of operation to the second sensor unit 19, except for the position in which it is arranged. List of reference symbols

[0106] 1Steering column 2Support unit 3Pivot axis 4Shroud unit 5Through openings 6Adjusting unit 7Steering spindle 8Control unit 9Adjustment device 10Adjustment device 11Position detection device 12Position detection device 13Adjustment drive 14Electric motor 15Threaded spindle 16Control lever 17End stop 18First sensor unit 19Second sensor unit 20Transmitter module 21Receiver module 22Adjustment drive 23First sensor unit 24Second sensor unit 25Transmitter module 26Receiver module 111Third sensor unit 210Receiver module LLteering spindle axis

Claims

1. A steering column (1) for a motor vehicle, comprising an actuating unit (6) in which a steering spindle (7) is rotatably mounted and which is held in an adjustable manner between an operator control area and a stowed area by a supporting unit (2), an adjustment device (9, 10) for adjusting the actuating unit (6) with respect to the supporting unit (2), and a position-sensing device (11, 12) which comprises a first sensor unit (18, 23) for sensing the position of the actuating unit (6) with respect to the supporting unit (2), characterized in that the position-sensing device (11, 12) comprises a second sensor unit (19, 24) for sensing a state when the actuating unit (6) is in a predetermined position relative to the supporting unit (2), wherein the predetermined position is a position which differs from the positions defined by the end stops of the actuating unit (6).

2. The steering column (1) as claimed in claim 1, characterized in that the first sensor unit (18, 23) is designed to operate in a contactless manner.

3. The steering column (1) as claimed in one of the preceding claims, characterized in that the second sensor unit (19, 24) is designed to operate in a contactless manner.

4. The steering column (1) as claimed in one of the preceding claims, characterized in that the sensor units (18, 19, 23, 24) are each designed to use the same measurement principles.

5. The steering column (1) as claimed in one of claims 1 to 3, characterized in that the sensor units (18, 19, 23, 24) are each designed to use different measurement principles.

6. The steering column (1) as claimed in one of the preceding claims, characterized in that the position-sensing device (11, 12) comprises a third sensor unit for sensing a second state when the actuating unit (6) is in a predetermined second position relative to the supporting unit (2).

7. The steering column (1) as claimed in one of the preceding claims, characterized in that the actuating unit (6) can be adjusted with respect to the supporting unit (2) in a longitudinal adjustment direction and / or a height adjustment direction.

8. A method for adjusting a steering column (1) as claimed in one of claims 1 to 7, comprising the following steps: - adjusting the actuating unit (6) with respect to the supporting unit (2) by means of the adjustment device (9, 10); - sensing the position of the actuating unit (6) by means of the first sensor unit (18, 23); - sensing a state by means of the second sensor unit (19, 24) when the actuating unit (6) is in a predetermined position relative to the supporting unit (2).

9. The method as claimed in claim 8, characterized in that the method has the following further steps: - comparing the position sensed by the first sensor unit (18, 23) with the predetermined position of the actuating unit (6) when the second sensor unit (19, 24) senses the state; - detecting a malfunction of one of the sensor units (18, 19, 23, 24) if the discrepancy determined by the comparison exceeds a stipulated threshold value.

10. The method as claimed in either of claims 8 and 9, characterized in that the method has the following further steps: - sensing a second state by means of a third sensor unit when the actuating unit (6) is in the predetermined second position relative to the supporting unit (2); - comparing the position sensed by the first sensor unit (18, 23) with the predetermined second position of the actuating unit (6) when the third sensor unit captures the second state; - detecting a malfunction of one of the sensor units (18, 19, 23, 24) if the discrepancy determined by the comparison exceeds a stipulated threshold value.

11. The method as claimed in either of claims 9 and 10, characterized in that the method has the following further step: - correcting the position of the first sensor unit (18, 23) if the malfunction is detected.

12. The method as claimed in one of claims 9 to 11, characterized in that the method has the following further step: - slowing down the adjustment of the actuating unit (6) with respect to the supporting unit (2).

13. The method as claimed in one of claims 9 to 12, characterized in that the method has the following further step: - stopping the adjustment of the actuating unit (6) with respect to the supporting unit (2).

14. A method for controlling subsystems of a motor vehicle having a steering column (1) as claimed in one of claims 1 to 7, comprising the following steps: - adjusting the actuating unit (6) with respect to the supporting unit (2) by means of the adjustment device (9, 10); - generating a state signal of the steering column (1) on the basis of the position of the actuating unit (6) during adjustment, wherein the state signal is a changeover, step or pulse signal; - detecting a first state of the steering column (1) if the state signal assumes or falls below or exceeds a first value, or detecting at least one further state of the steering column (1) if the state signal assumes or falls below or exceeds at least one further value or detecting a first state of the steering column (1) before the state signal has a pulse, or detecting at least one further state after the state signal has at least one pulse; - controlling the subsystem, which corresponds to the detected state according to a stipulation.