阅读说明：本技术 执行器设备以及用于在执行器设备情况下补偿杂散磁场的方法 (Actuator device and method for compensating stray magnetic fields in the case of an actuator device ) 是由 A·雷贝莱因 J·福姆多尔普 于 2019-09-11 设计创作，主要内容包括：说明一种电磁执行器设备(2)、尤其是线性执行器,其具有：-执行器(4),所述执行器具有至少一个执行器线圈(6)用于产生至少一个电磁场以及具有挺杆(8),所述挺杆能够根据所产生的至少一个电磁场在纵向(L)上和与纵向(L)相反地移动；-传感器装置(10),所述传感器装置具有发射器元件(12)和传感器元件(14),其中发射器元件(12)布置在挺杆(8)处,并且传感器元件(14)被构造用于根据由发射器元件(12)产生的磁场(18)产生测量信号(S-M),所述测量信号包含关于挺杆(8)沿着纵向(L)的当前实际位置的信息；以及-调节单元(20),所述调节单元具有调节器(22),所述调节器被设立用于在运行中根据基于测量信号(S-M)的位置信号(S-P)给至少一个执行器线圈(6)施加操控电压(U-A)用以产生至少一个电磁场,使得挺杆(8)从当前实际位置移动到额定位置,其中在运行中由至少一个执行器线圈(6)产生杂散磁场(26),对测量信号(S-M)进行适配,使得对测量信号(S-M)的由杂散场引起的影响得以补偿。(An electromagnetic actuator device (2), in particular a linear actuator, is specified, comprising: an actuator (4) having at least one actuator coil (6) for generating at least one electromagnetic field and having a tappet (8) which can be displaced in the longitudinal direction as a function of the generated at least one electromagnetic field(L) moving up and opposite to the longitudinal direction (L); a sensor device (10) having an emitter element (12) and a sensor element (14), wherein the emitter element (12) is arranged at the tappet (8) and the sensor element (14) is designed to generate a measurement signal (S) as a function of a magnetic field (18) generated by the emitter element (12) M ) -said measurement signal containing information about the current actual position of the tappet (8) in the longitudinal direction (L); and a control unit (20) having a controller (22) which is set up to determine the measurement signal (S) during operation M ) Position signal (S) of P ) Applying a control voltage (U) to at least one actuator coil (6) A ) For generating at least one electromagnetic field in order to move the tappet (8) from a current actual position into a target position, wherein a stray magnetic field (26) is generated during operation by the at least one actuator coil (6) for the measurement signal (S) M ) Adapting so that the measurement signal (S) is measured M ) The effects caused by stray fields are compensated for.)

1. An electromagnetic actuator device (2), in particular a linear actuator, having:

an actuator (4) having at least one actuator coil (6) for generating at least one electromagnetic field and having a tappet (8), which tappet (8) can be moved in a longitudinal direction (L) and counter to the longitudinal direction (L) as a function of the generated at least one electromagnetic field,

-a sensor device (10) having an emitter element (12) and a sensor element (14), wherein the emitter element (12) is arranged at the tappet (8) and the sensor element (14) is configured for generating a measurement signal (S) depending on a magnetic field (18) generated by the emitter element (12)_M) The measurement signal containing information about the current actual position of the tappet (8) in the longitudinal direction (L), an

A regulating unit (20) having a regulator (22), the regulator (22) being designed to base the measurement signal (S) on the basis of the measured signal (S) during operation_M) Position signal (S) of_P) To at least one actuator coil (6) Applying a control voltage (U)_A) For generating the at least one electromagnetic field such that the tappet (8) is moved from the current actual position into a target position, wherein

During operation, a stray magnetic field (26) is generated by the at least one actuator coil (6), said stray magnetic field influencing the measurement signal (S)_M) And wherein

The regulating unit (20) has a compensation device (28) which is designed to determine a variable (G) which is dependent on the stray magnetic field (26) and to adapt the measurement signal (S) as a function of the variable (G)_M) And to the regulator (22), wherein the measurement signal (S) is measured_M) Adapting such that the measurement signal (S) is_M) The effects caused by stray fields are compensated for.

2. Actuator device (2) according to the preceding claim, wherein the quantity (G) related to the stray magnetic field (26) is due to the steering voltage (U)_A) An actuator current (I) flowing in the at least one actuator coil_A）。

3. Actuator device (2) according to the preceding claim, wherein an evaluation unit (32) is furthermore arranged in the regulating unit (20), which evaluation unit is set up for determining a variable (G) which is dependent on the stray magnetic field (26), preferably the actuator current (I), from at least one state variable (Z) of the actuator (4)_A）。

4. Actuator device (2) according to the preceding claim, wherein the estimation unit (32) is immediately configured to determine a quantity (G) related to the stray magnetic field (26), preferably the actuator current (I), in particular depending on at least one of the following state quantities_A）：

-the last detected actuator current (I)_A），

-the temperature of the actuator,

-the resistance of the at least one actuator coil (6),

-an inductance of the at least one actuator coil (6),

-the position and speed of the tappet (8),

-a control voltage (U) of the actuator (4)_a）。

5. Actuator device (2) according to one of the preceding claims, wherein the compensation device (28) is designed such that it determines a correction variable from the determined variables (G) according to a correction function and adapts the measurement signal (S) according to the correction variable_M）。

6. Actuator device (2) according to the preceding claim, wherein a correction quantity determined from the correction function is corrected with a calibration value, wherein the calibration value is an offset and/or an amplification factor.

7. Actuator device (2) according to any of the preceding claims, wherein the emitter element (12) is configured as a permanent magnet.

8. Actuator device (2) according to any of the preceding claims, wherein the sensor element (14) is configured as a magnetic field sensor.

9. Actuator device (2) according to any of the preceding claims, wherein the emitter element (12) is arranged at the tappet (8) such that the direction of the magnetic field (18) generated by the emitter element (12) and the direction of the stray magnetic field at the measurement location where the sensor element (14) is arranged are substantially the same orientation.

10. Method for compensating stray magnetic fields in the case of an actuator device (2) according to one of the preceding claims, having:

an actuator (4) having at least one actuator coil (6) for generating at least one electromagnetic field and having a tappet (8), which tappet (8) can be moved in and counter to the longitudinal direction (L) as a function of the generated at least one electromagnetic field,

-a sensor device (10) having an emitter element (12) and a sensor element (14), wherein the emitter element (12) is arranged at the tappet (8) and a measurement signal (S) is generated by means of the sensor element (14) as a function of a magnetic field (18) generated by the emitter element (12)_M) The measurement signal containing information about the current actual position of the tappet (8) in the longitudinal direction (L), an

-an adjustment unit (20) having an adjuster (22), by means of which adjuster (22) the measurement signal (S) is based on_M) Position signal (S) of_P) Applying a control voltage (U) to the at least one actuator coil (6)_A) To generate the at least one electromagnetic field such that the tappet (8) is moved from the current actual position into a nominal position, and wherein a stray magnetic field is generated by the at least one actuator coil (6), which influences the measurement signal (S)_M) The method comprises the following steps:

-detecting a parameter (G) related to the stray magnetic field by means of a compensation unit (28),

-generating correction parameters based on the detected parameters (G),

-by applying said measurement signal (S)_M) Applying the correction variable to adapt the measurement signal (S)_M），

-will be based on the adapted measurement signal (S)_M) Position signal (S) of_P) To the regulator (22).

11. The method of the preceding claimMethod, wherein a correction variable is determined from the determined variables by means of a compensation device (28) as a function of a correction function, and the measurement signal (S) is adapted as a function of the correction variable_M) And wherein the correction variable determined from the correction function is corrected with a calibration value, wherein the calibration value is an offset and/or an amplification factor.

12. Method according to the preceding claim, wherein for determining the calibration value the tappet (8) is moved into a predefined and known calibration position, preferably into two end positions, once with an energized actuator (4) and once with a de-energized actuator (4), and the position of the tappet (8) is detected by means of the sensor device (10) respectively, and furthermore the values of the calibration position determined for the respective calibration position by means of the calibration function are compared with the actual values of the calibration position and the offset and the amplification factor are determined therefrom.

Technical Field

The invention relates to an actuator device and to a method for compensating stray fields in the case of such an actuator device.

Background

Actuator devices, in particular linear actuators, are used nowadays, in particular where, for example, a controlled and monitored linear movement in the longitudinal direction is required. Such linear actuators are used, for example, in the automotive industry in so-called shift-by-wire systems, in which the linear actuators perform a linear movement during operation for shifting.

In the simplest case, linear actuators usually have a substantially pin-like tappet which is surrounded by a so-called actuator coil. The actuator coil is therefore "wound around" the tappet, with a gap being formed between the actuator coil and the tappet. The principle of action of the actuator is based on known electromagnetic considerations. In this case, during operation, an actuation voltage is applied to the actuator coil, and an electromagnetic field is generated in the near field of the actuator coil as a result of an actuator current flowing in the actuator coil as a result of the actuation voltage. The generated electromagnetic field exerts a force on the tappet which, as a result of this force, moves in the longitudinal direction or counter to the longitudinal direction and thus executes a linear movement.

Such linear movements can often be controlled precisely, for example by adjusting (indirectly) the actuator current which accounts for the linear movement (for example by adjusting the actuator voltage). In order to obtain information about the current position of the tappet, such actuator devices usually have a position sensor. The position sensor is often designed in such a way that it likewise uses the (own, generated) magnetic field for determining the position of the tappet. A disadvantage in this case is that the two fields (the electromagnetic field of the actuator coil and the magnetic field of the position sensor) may unintentionally influence one another.

Starting from this, the invention is based on the object of specifying an actuator device in which the magnetic field-induced interference is at least reduced.

According to the invention, this object is achieved by an electromagnetic actuator device having the features of claim 1. Advantageous configurations, developments and variants are the subject matter of the dependent claims.

The electromagnetic actuator device is in particular designed as a linear actuator and is also referred to below simply as an actuator device.

The actuator device has an actuator with at least one actuator coil for generating at least one electromagnetic field. The actuator preferably has two actuator coils for generating two electromagnetic fields. Furthermore, the actuator has a tappet which can be displaced in the longitudinal direction and counter to the longitudinal direction as a function of the generated at least one magnetic field. The tappet is in particular pin-shaped.

Furthermore, the actuator device has a sensor device with an emitter element and a sensor element. In this case, the emitter element is arranged at the tappet. The sensor element is designed to generate a measurement signal as a function of a magnetic field generated by the transmitter element, which magnetic field is detected by the sensor element during operation. In this case, the generated measurement signal contains information about the current actual position of the tappet in the longitudinal direction. In other words, the sensor element detects different values (directions) of the magnetic field at different positions of the tappet, on the basis of which different measurement signals are then generated.

The actuator device also has an actuating unit with an actuator, which is designed to apply an actuating voltage to at least one actuator coil for generating at least one electromagnetic field as a function of a position signal based on the measurement signal during operation. In this case, a position signal based on the measurement signal is understood to mean that, based on the value of the measurement signal, the actual position of the tappet can be inferred, which is then transmitted to the actuator in the form of a position signal. The actuation voltage is applied to at least one actuator coil and, as a result, at least one electromagnetic field is generated for displacing the tappet, in particular from a current actual position to a (predefined) target position.

In operation, a (unintentional) stray magnetic field is generated by the actuator coil, which stray magnetic field (negatively) influences the measurement signal and thus also the position signal.

The control unit has a compensation device which is designed to determine a variable (also referred to as parameter for short) which is dependent on the stray magnetic field and to adapt the measurement signal as a function of this variable and to transmit it to the controller. The measurement signal is adapted such that it is adapted according to the determined variables in order to take account of the effects caused by stray fields, so that said effects are compensated with respect to the measurement signal and therefore also with respect to the position signal.

This configuration is based on the consideration that, as already mentioned, the sensor device, in particular the sensor element, detects stray magnetic fields from the sensor element in addition to the desired magnetic field, wherein the position of the tappet is indirectly detected by means of the magnetic field, which stray magnetic fields are formed during operation of the actuator and which superimpose the desired magnetic field in an interfering manner. That is, the magnetic field of the transmitter element is either unintentionally enhanced (by constructive addition of the stray magnetic field and the magnetic field) or unintentionally attenuated (by destructive addition of the stray magnetic field and the magnetic field) by the stray magnetic field, for example. In both superposition cases, this leads to stray field-induced effects on the measurement signal and thus also on the position signal, and the controller therefore obtains erroneous information about the current actual position of the tappet. The exact adjustment of the position of the tappet is thereby negatively influenced.

By determining a variable relating to the stray magnetic field on the compensation device side and adapting the measurement signal as a function of this variable, an undesired superposition of the stray magnetic field and the magnetic field is compensated for, so that a sufficiently precise adjustment of the position of the tappet is achieved. The particularly disturbing effects of stray magnetic fields are therefore preferably completely compensated for.

According to a preferred embodiment, the variable related to the stray magnetic field is an actuator current flowing in the at least one actuator coil as a result of the actuation voltage. This configuration is based on the following physical considerations: the resulting stray magnetic field is proportional to the actuator current flowing in the actuator coil. Furthermore, from a technical point of view, the detection of the actuator current can be realized simply and at low cost.

According to a preferred further development, an evaluation unit is also arranged in the control unit, said evaluation unit being designed to determine the actuator current as a function of at least one state variable of the actuator. This determination is made in particular when the actuator current cannot be measured or cannot be measured continuously.

In this case, the evaluation unit is particularly preferably designed to determine the actuator current, in particular as a function of at least one or more of the following state variables:

-the last detected actuator current,

-the temperature of the actuator,

-the resistance of at least one actuator coil,

-the inductance of at least one actuator coil,

the position and speed of the ram, and

actuator voltage (e.g. operating voltage + duty cycle in the case of PWM control).

In this case, the last detected actuator current is understood to be, in particular in the case of a temporary unavailability of a current measurement, for example, the last measured current value at which the current measurement is still available.

The compensation device is expediently designed such that it determines a correction variable (for example a correction value or a correction factor) from the determined variables according to a correction function. The measurement signal is then adapted during operation as a function of the correction variable such that the correction variable is applied to the measurement signal in order to take account of the effects caused by stray fields. The correction function is in this case in particular a function dependent on the actuator current for determining the correction variable. In other words, for different actuator currents occurring during operation, different correction variables are determined for adapting the measurement signal. In this way, it is possible to react to different actuator currents with regard to the adaptation of the measurement signal and thus with regard to the compensation of stray electromagnetic fields which are superimposed in an interfering manner with the magnetic field. Furthermore, this achieves: the adaptation of the measurement signal is carried out sufficiently accurately in each case independently of the level of the flowing actuator current.

Instead of determining the correction variables from the correction function and adapting the measurement signals as follows, the functional assignment between the actuator current value and the respective position of the tappet is stored in a table. This table is then stored, for example (in a manner that can be called up during operation), in the internal memory of the control unit.

According to a preferred refinement, the correction variables determined from the correction function are corrected by means of a calibration value. The calibration value is in this case preferably an Offset (Offset) and/or a magnification factor.

This configuration has the following advantages: the effects due to the relationship of the magnetic field and the stray electromagnetic field and/or the amplification errors of the actuator current measurement are equalized by an offset or amplification factor and the compensation is thereby favorably influenced.

The transmitter element is expediently configured as a permanent magnet. This results in a particularly simple and cost-effective design of the transmitter element with regard to the generation of the magnetic field.

The sensor element is furthermore expediently designed as a magnetic field sensor, for example as a (multi-axis) hall sensor. Alternatively, the receiving unit is configured as a magnetoresistive sensor. By configuring the receiving unit as a magnetic field sensor, a particularly simple and cost-effective configuration of the sensor element can be achieved, similar to the transmitter element being configured as a permanent magnet. In summary, a complete sensor device with an emitter element and a sensor element is thus achieved simply and cost-effectively.

According to a preferred configuration, the emitter element is arranged at the tappet such that the direction of the magnetic field generated by the emitter element and the direction of the stray magnetic field at the measurement location where the sensor element is arranged are substantially identically oriented (gleichgerichlet) (so that a constructive superposition of the two fields results therefrom). This configuration is based on the following considerations: the direction of the stray magnetic field and the direction of the magnetic field add in a vector addition to the resulting field. Furthermore, a sensor element, which is designed, for example, as a hall sensor or as a magnetoresistive sensor, requires a minimum value of the magnetic flux, so that an output signal, in this case a measurement signal, is generated. In the case of a substantially identical orientation of the directions of the generated magnetic field and of the stray magnetic field, it is therefore ensured on the one hand (by the value of the field derived) that the measurement signal is detected by the sensor element (u berhaupt) at all. Furthermore, the adaptation of the measurement signal for generating the position signal is significantly simplified compared to an orientation in which the directions of the two fields (magnetic field and stray magnetic field) are oriented opposite to one another, for example.

According to the invention, this object is also achieved by a method for compensating stray magnetic fields in the case of an actuator device having the features of claim 10. The actuator device is in this case in particular the actuator device already described above.

The advantages and preferred configurations listed in relation to the actuator device can be transferred to the method in a sense and vice versa.

The method is in particular a method which is carried out by means of the actuator device described above. In this case, the method comprises the steps of:

first, a parameter related to the stray magnetic field is detected by means of a compensation unit. In this case, the variable related to the stray magnetic field is preferably an actuator current which flows through at least one actuator coil during operation.

The correction variable is now generated on the basis of the detected variable. In this case, the generation is preferably carried out by means of a correction function as a function of the detected variables. The detected measurement signal is then adapted, wherein the generated correction variable is applied to the measurement signal.

A position signal is then generated on the basis of the adapted measurement signal and transmitted to the regulator, so that the current actual position of the tappet is adapted by means of the position signal on the basis of the adapted measurement signal. By adapting the measurement signal, the effects caused by stray fields are therefore compensated for, and the tappet is thus moved from the actual position to the predefined setpoint position, preferably without a deviation.

Preferably, a correction variable is determined from the determined variables by means of the compensation device as a function of the correction function. The measurement signal is adapted as a function of a correction variable, wherein the correction variable determined as a function of the correction function is corrected using the calibration value. In this case, the calibration values are preferably offsets and/or amplification factors.

According to an advantageous further development, the tappet is moved into a predetermined and, in particular, known calibration position in order to determine the calibration value. These known calibration positions are in particular the two end positions of the tappet. In this case, the end positions are understood to be the positions which the tappet assumes in the longitudinal direction and opposite to the longitudinal direction in the case of maximum deflection (Auslenkung), respectively.

The position of the tappet in the two end positions is determined once in the energized actuator, i.e. in the presence of a stray magnetic field, and once in the unenergized actuator, i.e. in the absence of a stray magnetic field. This determination has the following advantages: a deviation of the measuring signal containing information about the current actual position of the tappet can be detected simply and accurately. In other words, by detecting the position of the tappet without energizing the actuator, there is no disturbing stray field, so that the sensor device provides an accurate value of the position of the tappet. By detecting the measurement signal with the energized actuator, however, without changing the tappet position, it is possible to detect a measurement signal which is influenced by stray fields. The comparison of the two measurement signals thus provides the difference to be compensated, i.e. the influence caused by the stray field.

In addition, a correction variable is then generated on the basis of the correction function, and the correction variable is applied to a measurement signal which represents the position of the tappet in one of the two end positions. Thereby enabling compensation of the aforementioned difference caused by the correction function. Finally and in addition thereto, the measurement signal adapted by means of the correction function is again compared with the actually detected (i.e. determined without the actuator being switched on) measurement signal, and a possible offset and, in addition, an amplification factor are determined therefrom.

Since in this way the two end positions and thus the respective extreme positions in and opposite to the longitudinal direction of the tappet are calibrated, the calibration for adapting the measurement signal can be applied to all positions of the tappet lying between these two extreme positions.

Drawings

Embodiments of the invention are subsequently explained in more detail on the basis of the figures. The figure is partly in a very simplified illustration:

fig. 1 shows an actuator device with an actuator and an adjusting unit.

Detailed Description

The electromagnetic actuator device 2, which is also referred to below for simplicity as actuator device 2, has an actuator 4. The actuator 4 has at least one actuator coil 6 for generating at least one electromagnetic field. Furthermore, the actuator 4 has a tappet 8, which tappet 8 can be moved in the longitudinal direction L and counter to the longitudinal direction L as a function of the at least one electromagnetic field generated. In this exemplary embodiment, the tappet 8 is pin-shaped.

Furthermore, the actuator device 2 has a sensor device 10. The sensor device 10 has an emitter element 12 and a sensor element 14. In this embodiment, the emitter element 12 is arranged at the tappet 8. In particular, in this embodiment, the emitter element 12 is arranged at the upper end 16 of the tappet 8. The sensor element 14 is designed to generate a measurement signal S as a function of the magnetic field 18 generated by the transmitter element 12_M. Measuring signal S_MContaining information about the current actual position of the tappet 8 in the longitudinal direction L. In this embodiment, the transmitter element 12 is configured as a permanent magnet. Furthermore, in this embodiment, the sensor element 14 is configured as a hall sensor.

Furthermore, the actuator device 2 has an adjustment unit 20. The regulating unit 20 has a regulator 22. The regulator 22 is designed to operate on the basis of the measurement signal S_MPosition signal S of_PApplying a control voltage U to at least one actuator coil 6_AFor generating at least one electromagnetic field. For this purpose, the regulator 22 is connected, for example, by means of a power driver 24 (voltage source in this exemplary embodiment) in such a way that a control voltage U can be provided_A. The actuating unit 20 makes it possible to move the tappet 8 from the momentary actual position, for example, with the signal S_sollIn the form of a predetermined nominal position. In this case, the setpoint position is transmitted to the controller 22, for example, as an input variable.

In operation of the actuator device 2, a stray magnetic field 26 is generated by the actuator coil 6. The stray magnetic field influences the measurement signal S as follows_M: the exact adjustment of the actual position to the desired position is subject to error.

In order to compensate for this error (fehlerbehafung), the regulating unit 20 has in this embodiment a compensating device 28. The compensation device 28 is designed to determine a variable G associated with the stray magnetic field 26 and to adapt the measurement signal S as a function thereof_MAnd to the regulator 22. In this exemplary embodiment, the actuator current I flowing in the at least one actuator coil 6 as a result of the actuation voltage_AIs considered to be the quantity G associated with the stray magnetic field 26. For the measurement signal S_MAdapting so that measurements are takenSignal S_MIs compensated for the effects caused by stray fields. That is, due to the compensation by the compensation means 28, the regulator 22 obtains a measurement signal S based on a magnetic field that is not influenced by the stray magnetic field 26_MPosition signal S of_P. In other words, the presence is based on the measurement signal S_MPosition signal S of_PAs it were, without disturbing stray magnetic fields 26.

At armature current I_AIn this exemplary embodiment, the measurement of the variable G associated with the stray magnetic field 26 is carried out, for example, by means of a current measuring unit 30, which is additionally connected to the compensation unit 28 for transmitting the armature current I_A。

The adjustment unit 20 has an evaluation unit 32 as long as a direct determination of the quantity G associated with the stray magnetic field 26 cannot be detected or cannot be detected temporarily. The evaluation unit 32 is designed to determine a variable G associated with the stray magnetic field 26 from the further state variable Z of the actuator 4. In this exemplary embodiment, these further state variables Z are expediently likewise the armature current I_AAnd therefore also the stray magnetic field 26. Other state variables are thus, for example, the armature current I measured last_AControl voltage U_AThe actuator temperature, the measured or estimated resistance and/or the measured or estimated inductance of the at least one actuator coil 6 and, for example, the approximate position and/or speed of the tappet 8.

The present invention is not limited to the above-described embodiments. On the contrary, other variants of the invention can also be derived therefrom by the person skilled in the art without departing from the subject matter of the invention. In particular, all individual features described in connection with the embodiments can also be combined with one another in other ways without departing from the subject matter of the invention.

List of reference numerals

2 electromagnetic actuator device

4 actuator

6 actuator coil

8 tappet

10 sensor device

12 emitter element

14 sensor element

16 upper end part

18 magnetic field

20 regulating unit

22 regulator

24 power driver

26 stray magnetic field

28 compensating device

30 current measuring unit

32 estimation unit

L longitudinal direction

S_MMeasuring signal

S_sollNominal position signal

S_P Position signal

I_AArmature current

G parameter

U_AControl voltage

A Z state parameter.