DE202015009335U1 - Device for determining the parking position of an adjustable motor vehicle part - Google Patents

Abstract

Adjusting device (1) for determining a setting position (x) of a motor-adjustable motor vehicle part, with a rotatable, multi-pole ring magnet (13) and with a spaced therefrom arranged Hall sensor (14), the time or angle-dependent changes in the magnetic flux density (B1) detected by a rotational movement of the ring magnet (6) and converted by means of a switching unit (19) according to a predetermined switching rule with hysteresis (H1) in a binary pulse train (S), and with a control unit (11) which is adapted to by counting Level change of the pulse sequence (S) to determine a measure of the setting position (x), characterized by a memory (23) which is connected to the switching unit (19) such that it in an active phase (A1, A2) of the Hall Sensor (14), during which the magnetic field moves relative to the Hall sensor (14) and the Hall sensor (14) is activated, the current level of the binary pulse train (S) at least f for the time intervals for which the Hall voltage (U1 ') is in the range of the hysteresis (H1), non-volatile stores as reference value in the case of level changes, the control unit (11) being set up after an inactive phase (P) of the Hall sensor (14), during which the power to the Hall sensor (14) was completely turned off, at least to set an initial level of the binary pulse train (S) to the stored reference value when the Hall voltage (U1 ') in the hysteresis (H1) is located.

Description

The invention relates to an adjusting device according to the preamble of claim 1. Such an adjusting device is made DE 10 2009 034 664 A1 or off DE 20 2010 017 499 U1 known.

Adjustable motor vehicle parts ("adjusting elements") of the aforementioned type are, for example, a movable vehicle window, an adjustable vehicle seat or a part thereof, a side door or tailgate, a sunroof or a convertible top. The adjusting device associated with such an actuating element usually comprises an (electric) motor and an adjusting mechanism, via which the motor acts on the adjusting element. The actuator often further includes a control unit for driving the motor which, in turn, typically includes a microcontroller having control software (firmware) implemented therein or a non-programmed integrated circuit (e.g., an ASIC).

During a setting operation of such an actuating element is often a desired end position to approach precisely. For this purpose, a precise knowledge of the current setting position of the actuating element is always required during the setting process. The knowledge of the current parking position or derived therefrom variables, such as the actuating speed or the traversed travel, are also often required for the safe detection of a possible Einklemmfalls.

For precise detection of the parking position of a window is, for example DE 199 16 400 C1 known to provide a position and direction sensor. This consists essentially of two mutually offset at a distance or angle Hall sensors and a multi-pole, for example, two- or four-pole ring magnet, which is arranged on the drive shaft of the electric motor. The Hall sensors detect a magnetic field change due to a rotation of the fixedly connected to the drive shaft ring magnet and generate count pulses from this. These are evaluated together with information about the direction of rotation of the ring magnet and thus the electric motor by the counts are counted up or down depending on the direction of rotation of the drive and thus specify the respective position of the window.

For sensor technology usually integrated Hall sensors, for example in CMOS technology (Complementary Metal Oxide Semiconductor) are used, in addition to an evaluation, for example in ASIC technology, together with the sensitive surfaces (Hall probes) of the Hall sensor in a semiconductor chip are integrated (see. DE 101 54 498 B4 ).

A Hall probe is usually provided by e.g. formed square conductor plate, which is supplied with electrical energy from a current or voltage source. In the presence of an external magnetic field, a Hall voltage is induced in the Hall probe, which is proportional to the proportion of the magnetic flux density oriented perpendicular to the surface of the Hall probe. The Hall voltage is usually evaluated as a sensor signal.

From the DE 10 2006 043 839 A1 It is known to implement the magnetic field changes occurring at two Hall probes by means of a comparator circuit with hysteresis (Schmitt trigger) in two binary pulse trains staggered by 90 °, for example. By counting the pulses per unit of time, the speed is determined. By comparing the two pulse sequences, the direction of rotation of an associated rotary drive is determined.

When the ring magnet rotates, its magnetic poles move over the respective Hall probe. Each of the magnetic poles comes for a moment in direct opposition to the Hall probe. The magnetic field emanating from this magnetic pole passes in this state exactly or at least approximately perpendicularly through the Hall probe, as a result of which the Hall voltage induced in the Hall probe reaches a maximum or minimum. Between the above-described times, the pole boundary between two adjacent magnetic poles of the ring magnet brushes across the Hall probe. During these periods, the magnetic field emanating from the ring magnet passes through the Hall probe at an acute or even vanishing angle. In this case, the vertical portion of the flux density and the Hall voltage have a correspondingly reduced value and, if one of the pole boundaries is in exact opposition to the Hall probe and thus the magnetic field is aligned parallel to the Hall probe, a zero crossing on.

As a function of the orbital angle of the ring magnet relative to the Hall probe results for the orthogonal to the Hall probe aligned field component of the magnetic flux density, and thus also for the induced Hall voltage an at least approximately sinusoidal time course.

According to a switching rule which is common for Hall sensors (in particular for CMOS technology-based Hall sensors), the level of the output pulse train is switched from high (logic 1) to low (logical 0) when the depending on the orbital sinusoidal changing Hall voltage exceeds an upper switching threshold. This state is maintained until the Hall voltage falls below a lower switching threshold, whereby the level of the pulse train is reset to "low". As long as the Hall voltage is in the hysteresis (ie in the value range between the upper switching threshold and the lower switching threshold), the previously set level of the pulse train is maintained.

Particular attention needs to be given to starting the Hall sensor after an inactive phase during which the power to the Hall sensor is completely or partially turned off (sleep or sleep mode).

If, when starting the Hall sensor after such an inactive phase, the Hall voltage is outside the hysteresis (so far as the value of the Hall voltage exceeds the upper threshold or the lower threshold below), the level of the pulse train by the above switching rule is unique Are defined. This case is therefore not critical.

However, the level of the pulse train is not defined by the above switching rule if the Hall voltage is in hysteresis when the Hall sensor is started. To ensure a predictable behavior of the Hall sensor, in this case, the initial level of the pulse train after the start of the Hall sensor is specified - but this varies depending on the sensor concept. For example, in some conventional Hall sensors, the initial level is set to low for Hall voltage and high for negative Hall voltage. Other Hall sensors always set the initial level to the same value when starting in hysteresis (especially "high").

Regardless of the sensor concept, however, under certain circumstances, a pulse train sequence can occur in which the pulse sequence at start-up after the inactive phase has a different level than before the start of the inactive phase. In particular, further causes of this may be a slight rotation of the ring magnet or a drift (hysteresis) of the hysteresis during the inactive phase of the Hall sensor.

Such waveforms of the pulse train can lead to counting errors in the determination of the setting position (and thus to a miscalculation of the setting position).

According to DE 10 2009 034 664 A1 In order to avoid such counting errors following an inactive phase, the hysteresis is reduced if, at the beginning of the inactive phase, the Hall voltage exceeded the upper switching threshold by at most a predetermined tolerance range. This method, which is implemented by software in the Hall sensor, significantly reduces the probability of counting errors. Nevertheless, counting errors can not be completely ruled out with this method.

According to DE 20 2010 017 499 U1 Before a resting phase of the adjusting device, the position signals derived from the Hall voltage are stored in an integrated latch of the Hall sensor.

The invention has for its object to provide an actuating device which allows a particularly simple and suitable position determination of a motor-driven adjustable motor vehicle part ("control element") using a Hall sensor.

This object is achieved by the features of claim 1. Advantageous embodiments and modifications of the invention are set forth in the dependent claims and the description below.

The adjusting device according to the invention comprises a rotatable ring magnet and a spaced therefrom arranged Hall sensor detects the time or angle-dependent changes in the magnetic flux density due to a rotational movement of the ring magnet and converted by a switching unit according to a switching rule in a binary pulse train. The adjusting device furthermore comprises a memory which is connected to the switching unit in such a way that, in the or each active phase of the Hall sensor, it reads the current value of the binary pulse sequence at least for those time intervals for which the Hall voltage is in the hysteresis. during level changes (especially at each level change) non-volatile stores as a reference value. The actuator also includes a controller configured to, after the or each inactive phase of the Hall sensor, set the initial level of the binary pulse train to the stored reference value at least when the Hall voltage is in hysteresis.

The control unit is in particular configured to determine the setting position of a motor-driven, adjustable motor vehicle part by means of the Hall sensor, which is arranged in the rotatable magnetic field of the ring magnet. In this case, the periodic change in the magnetic flux density detected by the Hall sensor is converted into the binary pulse sequence in accordance with the predetermined switching rule, from which a measure for the actuating position is then determined by counting level changes (flanks). According to the predetermined switching rule, the level of the pulse signal becomes in each case then changed (ie switched) when a Hall voltage induced by the flux density exceeds a predetermined upper switching threshold. The level of the pulse signal is also changed in each case even if the Hall voltage falls below a lower threshold.

The lower switching threshold is spaced from the upper switching threshold by a predetermined hysteresis. The term "hysteresis" thus refers to the value range of the Hall voltage lying between the upper switching threshold and the lower switching threshold.

As a "binary pulse train," an electrical voltage signal is conveniently generated which alternates between two discrete levels (i.e., voltage) values. These levels are hereinafter referred to in a conventional manner as "high" (corresponding to, for example, + 5V) and "low" (corresponding to, for example, + 0.5V). A (also referred to as "flank") level change of the pulse train, thus indicating a switching operation in which the level of the pulse train from "high" to "low", or from "low" to "high" is switched.

The invention is based on a Hall sensor, which is operated intermittently in active phases, wherein the active phases in each case inactive phases are interposed. The "active phases" of the Hall sensor are characterized in that the magnetic field moves relative to the sensitive surface (Hall probe) of the Hall sensor, and that the Hall sensor is activated and thus generates and outputs the pulse train. On the other hand, the "inactive phases" of the Hall sensor are characterized in that the power supply of the Hall sensor is completely switched off.

According to the invention, in one (preferably in each) active phase of the Hall sensor, the current level of the binary pulse train is non-volatile stored as a reference value at least for those time intervals for which the Hall voltage is in the hysteresis at level changes (in particular at each level change) , In this case, a storage of the reference value is referred to as "non-volatile" ("persistent"), which survives at least partial disconnection of the power supply of the Hall sensor (corresponding to a sleep or sleep mode). Preferably, however, the storage of the reference value takes place in such a way that the stored reference value is maintained even when the Hall sensor is completely switched off (currentless switching).

When starting the Hall sensor after the inactive phase, an initial level of the binary pulse train is set to the stored reference value at least when the Hall voltage is in hysteresis at that time (ie, having a value between the upper threshold and the lower threshold) , The initial level is the first level value ("high" or "low"), which the pulse sequence assumes after the inactive phase.

The above-described storage of the reference value has the effect that the level of the pulse sequence last assumed within an active phase of the Hall sensor is conserved as reference value via the subsequent inactive phase of the Hall sensor. This ensures that the pulse train after the inactive phase starts at the same level it last had at the end of the previous active phase in a simple and error-prone manner. As a result, counting errors in the determination of the setting position from the pulse train are avoided, which in turn ensures a particularly precise determination of the setting position.

In a particularly simple and efficient embodiment of the invention, the current value of the pulse train during the entire active phase - regardless of the value of the Hall voltage - non-volatile stored at each level change. In an expedient embodiment of the invention, in addition, the initial level of the pulse train - regardless of the value of the Hall voltage at the beginning of the active phase - is always set to the stored reference value. In particular, for the determination of the setting position, preferably that pulse sequence which results from the time-varying, stored reference value is used for the sake of simplicity.

Alternatively, after the inactive phase, the initial level of the pulse train is set to the stored reference value only when the Hall voltage at the beginning of the active phase is in hysteresis. In contrast, the initial level is determined according to the above-described switching rule from the current value of the Hall voltage when the Hall voltage at the beginning of the active phase is outside the hysteresis (that is, a value exceeding the upper threshold, or a value below the lower threshold ).

In order to prevent the Hall voltage in the inactive phase from drifting out of the hysteresis or drifting into the hysteresis, due to movement of the magnetic field (more precisely of the magnetic field generating ring magnet), possibly slight, relative to the Hall probe subsequent active phase in the then resumed pulse sequence, if necessary, a flank caused too much or too little, the Movement of the magnetic field preferably mechanically blocked during the inactive phase.

The memory is connected in a particularly simple and efficient design of the adjusting device with the switching unit such that it non-volatile stores the current level of the pulse train during the entire active phase - regardless of the value of the Hall voltage - at each level change.

The control unit is designed in an expedient embodiment of the invention to always set the initial level of the pulse train at the beginning of the or each active phase - regardless of the value of the Hall voltage - always on the stored reference value.

Alternatively, after the inactive phase of the Hall sensor, the control unit is configured to determine the initial level of the binary pulse train from the current value of the Hall voltage according to the switching rule when the Hall voltage at the beginning of the active phase is outside the hysteresis located.

In an expedient embodiment, the adjusting device additionally comprises an electric servo motor, with the motor shaft of the ring magnet is rotatably coupled, wherein the motor shaft acts on the actuating element via an actuating mechanism. The switching unit is preferably formed by a comparator circuit with hysteresis (in particular by a so-called Schmitt trigger).

The Hall sensor is preferably designed as a CMOS semiconductor chip, in which the switching unit (in particular the comparator circuit described above) is integrated, so that as the output signal of the Hall sensor directly the binary pulse train as a measure of the rotational speed of the ring magnet can be tapped. In addition to this binary pulse train, the Hall sensor preferably generates a phase-shifted second pulse train and outputs a second output signal obtained from the comparison of these two pulse trains which is characteristic of the direction of rotation of the ring magnet.

The control unit is preferably formed by a microcontroller having a control program (firmware) implemented therein executable or by a non-programmable electronic circuit (in particular an ASIC).

The memory provided for non-volatile storage of the reference value is preferably designed as an integral part of the Hall sensor. Alternatively, the memory is designed as a separate component or as an integrated component of the control unit (ie in particular of the microcontroller or ASICS). Preferably, this memory is a one-bit memory. In this embodiment, the memory may be formed in the context of the invention, for example, by a bistable, electromechanical relay.

Preferably, the adjusting device further comprises means for mechanically blocking a movement of the ring magnet in the inactive phase of the Hall sensor - ie means which prevent rotation of the ring magnet (and thus the magnetic field) relative to the Hall probe, when the Hall Sensor is in the inactive phase and therefore could not detect such a rotation. The said means are formed for example by a brake or detent, are blocked by the deactivation of the Hall sensor, the ring magnet or a shaft rotatably connected thereto, and is automatically released upon re-activation of the Hall sensor. In an alternative embodiment, as a means for mechanically blocking the movement of the ring magnet as part of an actuating mechanism of the adjusting device, the adjusting device comprises a self-locking gear, e.g. a worm gear, which prevents a driven side driven rotation of the non-rotatably connected to the ring magnet motor shaft. The Hall sensor is expediently coupled in terms of power supply with the servomotor, so that the Hall sensor is always activated when the engine is operated, and is deactivated when the engine is de-energized. In the inactive phases of the Hall sensor, a rotation of the motor shaft is prevented here by the self-locking gear.

An embodiment of the invention will be explained in more detail with reference to a drawing. Show:

1 in a schematically simplified perspective view of a motor actuating device for an adjustable vehicle part, here a vehicle window, with a drive-side ring magnet and with a Hall sensor with downstream control unit,

2 in a schematic block diagram of the ring magnet, the Hall sensor and the control unit of the adjusting device according to 1 , and

3 in three superimposed, synchronous diagrams an exemplary time profile of the Hall probe detected by the Hall sensor Hall voltage (top diagram), a corresponding course of a derived from a comparator circuit of the Hall sensor from the Hall voltage pulse train (middle Diagram), and the corresponding course of a in turn derived therefrom further pulse train (speed signal), from which then a measure of the parking position of the vehicle part is determined by the downstream control unit (lower diagram).

Corresponding parts and sizes are always provided with the same reference numerals in all figures.

1 schematically shows a trained as a window actuator 1 for an adjustable motor vehicle part, which in the example shown is a vehicle window 2 is.

The adjusting device 1 includes an electric servomotor 3 that has an actuating mechanism 4 mechanically with the vehicle window 2 coupled is that the vehicle window 2 through the servomotor 3 along a travel path 5 reversible between two end positions, namely an open position 6 and a closed position 7 , is movable. The location of the vehicle window 2 in the open position 6 and the closed position 7 is in 1 each indicated by dashed lines. With solid lines is the vehicle window 2 in a lying between these end positions (arbitrarily drawn in the representation) actuating position x.

The adjusting mechanism 4 includes one on a motor shaft 8th of the servomotor 3 applied drive screw 9 that with a worm wheel 10 combs.

The adjusting device 1 further comprises a control unit 11 in the form of a microcontroller with a control software (firmware) implemented therein and a rotary position sensor 12 ,

The rotary position sensor 12 includes one on the motor shaft 8th rotatably mounted multi-pole (exemplified four-pole) ring magnet 13 and a cooperating with this Hall sensor 14 ,

How out 2 can be seen, includes the Hall sensor 14 two sensitive surfaces, hereafter referred to as Hall probes 15 and 16 are designated. Every Hall probe 15 . 16 is in each case an amplifier and filter circuit 17 respectively. 18 downstream. Each of the two amplifier and filter circuits 17 . 18 includes, for example, an operational amplifier and a bandpass filter.

Each of the two amplifier and filter circuits 17 . 18 Each is a switching unit in the form of a Schmitt trigger 19 respectively. 20 (ie a comparator circuit with hysteresis) downstream. To specify a respective hysteresis H ₁ or H ₂ each of the two Schmitt trigger 19 . 20 each a hysteresis circuit 21 respectively. 22 assigned.

The Schmitt trigger 19 on the one hand is a non-volatile (one-bit) memory 23 downstream, ie a memory which stores a binary information current independent. The memory 23 is formed in particular by a flash memory or a bistable, electromechanical relay with upstream differentiator.

Both Schmitt triggers 20 on the other hand, is a direction detection circuit 24 downstream.

During operation of the servomotor 3 generated with the motor shaft 8th co-rotating ring magnet 13 at the place of the Hall probe 15 a periodically oscillating, magnetic flux density B ₁ , whose to the Hall probe 15 perpendicular (orthogonal) portion temporally oscillates periodically. At the place of the Hall probe 16 generates the ring magnet 13 a magnetic flux density B ₂ phase-shifted with a corresponding, but the flux density B ₁ to the course of the Hall probe 16 vertical share.

Under the influence of the flux densities B ₁ and B ₂ is in the Hall probes 15 . 16 each generates an electrical Hall voltage U ₁ and U ₂ . The amount of the Hall voltage U ₁ , U ₂ is always proportional to that of the surface of the Hall probe 15 respectively. 16 vertical part of the flux density B ₁ or B ₂ . An exemplary, time course of the Hall voltage U ₁ is in the upper diagram of 3 plotted. The Hall voltage U ₂ has a corresponding, compared to the Hall voltage U ₁ but phase-shifted course.

The Hall voltages U ₁ and U ₂ are by means of the respectively downstream amplifier and filter circuit 17 respectively. 18 reinforced and filtered. An amplified and filtered Hall voltage U ₁ 'or U ₂ ' is then the respective downstream Schmitt trigger 19 respectively. 20 fed.

• – von „High“ auf „Low“, wenn der Wert der Hall-Spannung U₁‘ eine obere Schaltschwelle U_h übersteigt, und
• – von „Low“ auf „High“, wenn der Wert der Hall-Spannung U₁‘ eine untere Schaltschwelle U_l unterschreitet.

Each of the two Schmitt triggers 19 . 20 derives from the respectively supplied Hall voltage U ₁ 'and U ₂ ' according to a predetermined switching rule, a binary pulse signal I ₁ or I ₂ from. As in the upper diagram of the 3 is shown, switches the Schmitt trigger 19 in accordance with this switching rule the level of the pulse signal I ₁ always

• From "high" to "low" when the value of the Hall voltage U ₁ 'exceeds an upper switching threshold U _h , and
• - From "low" to "high" when the value of the Hall voltage U ₁ 'falls below a lower threshold U _l .

The through the hysteresis circuit 21 certain hysteresis H _{1 of} the Schmitt trigger 19 is hereby formed by the range of values between the upper switching threshold U _h and the lower switching threshold U _l .

The respective current level of the pulse train I ₁ is in the memory 23 stored non-volatile as a reference value. In regular operation, so with each level change (ie with each edge) of the pulse train I ₁ and the memory in the memory 23 stored reference value changed. From the time-dependent reference value, a modified pulse train is derived, which as - for the rotational speed of the motor shaft 8th Characteristic - Speed signal S via a speed output 25 of the Hall sensor 14 to the downstream control unit 11 is issued.

In the same way are the Schmitt trigger 20 through the hysteresis circuit 22 (not explicitly shown) upper and lower thresholds specified. The Schmitt trigger 20 switches the level of the pulse signal I ₂ analogously 3 when the upper switching threshold is exceeded "High" to "Low", and falls below the lower switching threshold of "Low" to "High".

The two pulse signals I ₁ , I ₂ are in the direction detection circuit 24 compared to each other. From the phase offset of the pulse signals I ₁ , I ₂ (concretely from the order in which corresponding pulses in the pulse signals I ₁ , I ₂ follow each other) passes the direction detection circuit 24 a binary directional signal R from that via a directional output 26 of the Hall sensor 14 to the downstream control unit 11 is issued.

By counting the successive level changes (flanks) in the speed signal S, the control unit determines 11 a measure of the current parking position x of the vehicle window 2 , The value of the directional signal R determines whether the measure for the positioning position x is lowered or increased by the number of edges counted.

The Hall sensor 14 is power supply technology preferably with the servomotor 3 coupled and is thus only supplied with power, although the servomotor 3 is energized. The Hall sensor 14 is therefore always and only active when the motor shaft 8th and the ring magnet mounted thereon 13 rotate. The Hall sensor 14 On the other hand, it is always inactive when the servo motor 3 is turned off, and thus the rotation of the motor shaft 8th comes to a halt. A rotation of the motor shaft 8th with de-energized servomotor 3 and inactive Hall sensor 14 becomes self-locking with the worm wheel 10 meshing drive screw 9 blocked.

3 shows in synchronous diagrams, in each case against the time t, an exemplary course of the Hall voltage U ₁ , the pulse train I ₁ and the speed signal S during two active phases A ₁ and A _{2 of} the Hall sensor 14 , which are interrupted by an inactive phase P. The pulse signal I ₁ and the speed signal S are substantially identical during the active phases A ₁ and A ₂ .

At the end of the first active phase A _{1, however} , the Hall voltage U ₁ in the illustrated example is in the hysteresis H ₁ , whereby the level of the pulse train I ₁ at the beginning of the second active phase A ₂ is not determined uniquely by the switching rule described above , The Schmitt trigger 19 is exemplary designed to always start the pulse signal I ₁ in this case with a high level. This leads according to 3 in that the pulse sequence I _{1 has} different levels at the end of the first active phase A ₁ and at the beginning of the second active phase A ₂ , without this level difference having one rotation of the ring magnet 13 would be connected. For this purpose, in the pulse signal I ₁ generated during the second active phase A ₂ , the first edge which, according to the above-described switching rule, would have to occur at the time at which the Hall voltage U ₁ in the second active phase A ₂ first times the lower switching threshold U _{l falls} below.

If the pulse sequence I _{1 were used} directly to determine the setting position x, then the control unit would 11 specify the change in the positioning position x too small due to the missing edge by one counting interval.

Through the intermediate memory 23 This counting error is avoided by storing in memory 23 the last level of the pulse train I ₁ (and thus also the last level of the speed signal S) are preserved before the inactive phase P. Through the store 23 For example, the initial level which the speed signal S first assumes in the second active phase A _{2 is} set to the stored reference value, and thus to the last level which the speed signal S had assumed before the inactive phase P. The deviating initial level of the pulse train I ₁ at the beginning of the second active phase A ₂ , however, is not in the memory 23 taken because its occurrence is not connected to a level change (ie an edge) of the pulse train I ₁ .

This ensures that the speed signal S is started in the second active phase A2 having the same level, which it had in the first active phase A ₁ last is ensured.

The invention will be particularly apparent to the embodiment described above, but is not limited to this. Rather, numerous other embodiments of the invention may be inferred from the claims and the foregoing description.

LIST OF REFERENCE NUMBERS

1

locking device

2

vehicle window

3

servomotor

4

actuating mechanism

5

Travel Range

6

open position

7

closed position

8th

motor shaft

9

drive worm

10

worm

11

control unit

12

Rotary position sensor

13

ring magnet

14

Hall sensor

15

Hall probe

16

Hall probe

17

Amplifier and filter circuit

18

Amplifier and filter circuit

19

Schmitt trigger

20

Schmitt trigger

21

hysteresis circuit

22

hysteresis circuit

23

(One-bit) memory

24

Direction detection circuit

25

speed output

26

towards the exit

B ₁

flux density

B ₂

flux density

U _h

(upper) switching threshold

U _l

(lower) switching threshold

I ₁

pulse signal

I ₂

pulse signal

H ₁

hysteresis

H ₂

hysteresis

U ₁

Hall voltage

U ₂

Hall voltage

U ₁ '

Hall voltage

U ₂ '

Hall voltage

S

speed signal

R

direction signal

A ₁

(active) phase

A ₂

(active) phase

P

(inactive) phase

x

setting position

t

Time

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009034664 A1 [0001, 0016]
• DE 202010017499 U1 [0001, 0017]
• DE 19916400 C1 [0004]
• DE 10154498 B4 [0005]
• DE 102006043839 A1 [0007]

Claims (5)

Adjusting device ( 1 ) for determining a parking position (x) of a motor-driven motor vehicle part, with a rotatable, multi-pole ring magnet ( 13 ) and with a spaced therefrom arranged Hall sensor ( 14 ), the time or angle-dependent changes in the magnetic flux density (B ₁ ) due to a rotational movement of the ring magnet ( 6 ) and by means of a switching unit ( 19 ) converted according to a predetermined switching rule with hysteresis (H ₁ ) in a binary pulse train (S), and with a control unit ( 11 ), which is set up by counting level changes of the pulse train (S) to determine a measure of the positioning position (x), characterized by a memory ( 23 ), which in such a way with the switching unit ( 19 ) is connected in an active phase (A ₁ , A ₂ ) of the Hall sensor ( 14 ) during which the magnetic field relative to the Hall sensor ( 14 ) and the Hall sensor ( 14 ), the current level of the binary pulse train (S) at least for the time intervals for which the Hall voltage (U ₁ ') is in the range of hysteresis (H ₁ ), non-volatile stores as reference value in level changes, wherein the Control unit ( 11 ) is arranged after an inactive phase (P) of the Hall sensor ( 14 ), while the power of the Hall sensor ( 14 ) was completely turned off, at least to set an initial level of the binary pulse train (S) to the stored reference value when the Hall voltage (U ₁ ') is in the hysteresis (H ₁ ). Adjusting device ( 1 ) according to claim 1, wherein the control unit ( 11 ) is arranged after the inactive phase (P) of the Hall sensor ( 14 ) to determine the initial level of the binary pulse train (S) according to the switching rule from the current value of the Hall voltage (U ₁ '), when the Hall voltage (U ₁ ') is outside the hysteresis. Adjusting device ( 1 ) according to claim 1 or 2, comprising means for mechanically blocking a movement of the ring magnet ( 13 ) during the inactive phase (P) of the Hall sensor ( 14 ). Adjusting device ( 1 ) according to one of claims 1 to 3, wherein the switching unit by a comparator circuit ( 19 ) is formed. Adjusting device ( 1 ) according to one of claims 1 to 4, wherein the memory is a one-bit memory ( 23 ) is trained.

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