DE102022209473B3 - Method for calibrating a sensor device - Google Patents

Abstract

A method for calibrating a sensor device (10), which is suitable for detecting a torque (M) acting on an actuator (2) of an adjustable roll stabilizer (1) using the principle of inverse magnetostriction, wherein the sensor device (10) has an at least partially comprising a primary sensor formed by an actuator housing (4) and a secondary sensor arranged in the actuator housing (4), the method comprising the following steps: a) producing a sensor unit (11) serving as a secondary sensor, comprising a sensor housing (23) which has a coil arrangement ( 12, 13), b) bringing the sensor unit (11) together with a pattern (30) similar to the primary sensor of the actuator (2) to form a pattern sensor device (37), c) carrying out a temperature calibration of the pattern sensor device (37), d) separating the sensor unit (11) from the pattern (30), e) bringing the sensor unit (11) together with the actuator housing (4) in order to produce an actuator (2) with a sensor device (10) which at least partially passes through the actuator housing (4) formed primary sensor and the sensor unit (11) serving as a secondary sensor, f) carrying out a load calibration of the sensor device (10).

Description

The invention relates to a method for calibrating a sensor device according to the features of claim 1. In addition, the invention relates to a pattern for calibrating a sensor device according to claim 11.

DE 10 2015 209 286 A1 discloses, in general, an arrangement for measuring a force and/or a torque on a machine element having a magnetization region. The arrangement includes at least two spaced magnetic field sensors and a measurement signal processing unit.

Out of DE 10 2011 078 819 A1 An (actively) adjustable roll stabilizer for a motor vehicle is known, between the two stabilizer sections of which an actuator is arranged, with which the stabilizer sections can be rotated relative to one another about an axis of rotation. A sensor device based on the active principle of (passive) inverse magnetostriction comprises a magnetically coded primary sensor on a stabilizer part and a magnetic field sensor acting as a secondary sensor, which converts changes in the magnetic field of the primary sensor - caused by a torque acting on the roll stabilizer about the axis of rotation - into an electrical one Converts signal. The torque acting on the roll stabilizer can be determined from this.

DE 10 2018 218 598 A1 discloses a sensor device operating on the principle of (active) inverse magnetostriction, which according to one in the there 4 shown embodiment is arranged with respect to the secondary sensor within an actuator housing of the actuator.

In order to achieve the desired accuracy for the operational use of the adjustable roll stabilizer of a sensor device that works according to the principle of active inverse magnetostriction, it is advisable to calibrate it before putting the adjustable roll stabilizer into operation. Different influencing variables are known that influence the measurement result achieved with the sensor device. The main influencing factors here include the temperature, the load (the torque acting on the adjustable roll stabilizer), the position of the secondary sensor relative to the primary sensor (here: the actuator housing), the condition of the primary sensor (part of the actuator housing), assembly influences such as those caused in particular by joining processes ), the magnetization, although this list should not be viewed as exhaustive.

It is an object of the present invention to provide a method for calibrating a sensor device of the type mentioned at the outset, with which a high level of accuracy of the sensor device can be achieved with reasonable handling effort.

• Herstellen einer als Sekundärsensor dienenden Sensoreinheit, aufweisend ein Sensorgehäuse, das eine Spulenanordnung aufnimmt,
• Zusammenbringen der Sensoreinheit mit einem dem Primärsensor des Aktuators ähnelnden Muster zu einer Muster- Sensoreinrichtung,
• Durchführen einer Temperaturkalibrierung der Muster-Sensoreinrichtung,
• Trennen der Sensoreinheit vom Muster,
• Zusammenbringen der Sensoreinheit mit dem Aktuatorgehäuse, um einen Aktuator mit einer Sensoreinrichtung herzustellen, die den zumindest bereichsweise durch das Aktuatorgehäuse gebildeten Primärsensor und die als Sekundärsensor dienende Sensoreinheit umfasst,
• Durchführen einer Lastkalibrierung der Sensoreinrichtung.

The object is achieved by a method according to the features of claim 1. This is a method for calibrating a sensor device which is suitable for detecting a torque acting on an actuator of an adjustable roll stabilizer using the principle of inverse magnetostriction. The sensor device comprises a primary sensor formed at least in some areas by an actuator housing and a secondary sensor arranged in the actuator housing. According to the invention, the calibration method includes the following steps:

• Producing a sensor unit serving as a secondary sensor, having a sensor housing that accommodates a coil arrangement,
• Combining the sensor unit with a pattern similar to the primary sensor of the actuator to form a pattern sensor device,
• Carrying out a temperature calibration of the sample sensor device,
• Separating the sensor unit from the pattern,
• Bringing the sensor unit together with the actuator housing in order to produce an actuator with a sensor device which comprises the primary sensor formed at least in some areas by the actuator housing and the sensor unit serving as a secondary sensor,
• Carrying out a load calibration of the sensor device.

The method according to the invention for calibrating the sensor device is therefore integrated into the manufacturing process of the actuator. This includes two types of calibrations: a temperature calibration and a load calibration; Because it has been shown that with knowledge of these two influencing factors, the sensitivity and also the zero position (“offset”) can be determined sufficiently reliably. This is based on the knowledge that load and temperature as well as their interaction can be described by third degree polynomials. The desired behavior, which is independent of temperature influences and linear to the magnitude of the torque, can be achieved by linearization using the polynomials mentioned. Minor deviations are tolerable. The parameters (coefficients) of the polynomials can be adjusted individually for the actuator in the various calibration steps provided according to the invention (temperature calibration, load calibration). has an individual pairing of sensor unit and actuator housing.

According to the method steps according to the invention, a sensor unit serving as a secondary sensor is first produced, which has a sensor housing that accommodates a coil arrangement. Subsequently, the sensor unit is brought together with a pattern similar to the primary sensor of the actuator to form a pattern sensor device. Accordingly, the sample is not yet the later actuator housing, but rather a separate, easy-to-handle component suitable for the purpose of temperature calibration, which expediently has smaller overall dimensions than the later actuator housing, but which has a magnetostrictive behavior under the influence of temperature that is comparable to the actuator housing .

The present sample sensor device consisting of sensor unit and sample is then subjected to a temperature calibration. In particular, the pattern sensor device is placed in an oven to expose it to different temperatures. Due to the smaller structural dimensions of the sample - compared to the later actuator housing - the temperature calibration can be carried out with significantly reduced handling effort.

After carrying out the temperature calibration of the sample sensor device, the sensor unit is separated from the sample again. The sensor unit is then mounted on the actuator housing in order to finally produce an actuator with a sensor device. The sensor device of the actuator includes the primary sensor formed at least in some areas by the actuator housing and the sensor unit serving as a secondary sensor.

In a final method step, a load calibration of the sensor device installed on the actuator is carried out, which corresponds to a load calibration of the assembled overall system.

As a result, the described calibration scheme for the sensor device can achieve a high level of measurement accuracy with little handling effort. In particular, a zero position (offset) of the sensor device can be determined by means of temperature calibration (load-free). The task mentioned at the beginning is thus solved.

While carrying out the temperature calibration, the sample sensor device is expediently exposed to different temperatures in a mechanically unloaded state. The sample used is correspondingly stress-free during calibration. Advantageously, only the temperature is changed while the temperature calibration is being carried out. This ensures that the measurement results achieved are free from other influences.

The temperature calibration described here by means of the pattern sensor device preferably serves to determine a zero position or an offset of the pattern sensor device.

It should be noted that in order to achieve representative measurement results during the temperature calibration, the sensor unit is brought together with the sample in the same way as possible as is later done with the actuator housing. In particular, the sensor housing of the sensor unit is advantageously pressed against the pattern in a manner comparable to that of the actuator housing when installed on the actuator.

In order to achieve measurement results that are as unimpaired as possible, the actuator is preferably subjected to different torques at a normal temperature in the step of carrying out the load calibration. Preferably, only the torque load on the actuator is changed during the load calibration.

The calibration data recorded in each case is expediently recorded while the temperature calibration and/or the load calibration is being carried out. Advantageously, based on the calibrations, a behavior of the sensor device that characterizes the actuator, in particular a relationship between temperature and load influence that applies to the specific sensor device, is determined and assigned to this, in particular stored in an electronic control unit associated with the actuator.

An advantageous development of the method provides that the pattern is a component serving the purpose of temperature calibration, which is preferably modeled on a segment of the actuator housing and/or at least has a magnetostrictive behavior under the influence of temperature that is comparable to the actuator housing.

In order to achieve representative measurement results and to ensure the functionality of the actuator, further steps in the production of the actuator are advantageously carried out in connection with the bringing together of the sensor unit with the actuator housing. This can include steps such as connecting the sensor unit to the actuator gate housing, closing the actuator housing and the like.

The task mentioned at the beginning is also solved by a pattern according to the features of claim 11. This is a pattern for calibrating a sensor device as part of a calibration method of the type described above. According to the invention, the pattern with the sensor unit can be converted into a pattern sensor device bring together and has a magnetostrictive behavior under the influence of temperature that is comparable to the actuator housing.

According to a preferred development of the pattern, this is modeled on a segment of the actuator housing. Compared to the actuator housing, the sample has smaller structural dimensions, which results in reduced handling effort, particularly for temperature calibration.

• 1 einen aktiv verstellbaren Wankstabilisator eines Kraftfahrzeugs, in Zusammenwirkung mit gegenüberliegenden Radaufhängungen der rechten und linken Fahrzeugseite in schematischer Ansicht,
• 2 einen Aktuator eines verstellbaren Wankstabilisators mit Sensoreinrichtung zur Drehmomenterfassung in vereinfacht schematischer Darstellung,
• 3 eine an einem wie in 2 dargestellten Aktuator zum Einsatz kommende Sensoreinrichtung im axialen Schnitt des Aktuators in schematisch vereinfachter Darstellung,
• 4 eine Sensoreinheit einer Sensoreinrichtung in perspektivischer Darstellung von radial schräg außen,
• 5 die Sensoreinrichtung gemäß 4 in perspektivischer Schnittdarstellung, schräg von der Seite,
• 6 die Sensoreinheit der 4 und 5, angeordnet im Aktuatorgehäuse (Hohlwelle) eines Aktuators im axialen Schnitt, wobei aus Darstellungsgründen übrige Elemente des Aktuators weggelassen sind,
• 7 die im Aktuatorgehäuse (Hohlwelle) angeordnete Sensoreinheit (Sekundärsensor) im Anordnungszustand wie in 6 in perspektivischer Ansicht von schräg oben,
• 8 die Sensoreinheit in einer alternativen perspektivischen Darstellung von radial außen,
• 9 die Sensoreinheit in perspektivischer Darstellung schräg von der Seite,
• 10 die Sensoreinheit in Draufsicht,
• 11 a eine Sensoreinheit (Sekundärsensor), die zwecks Temperaturkalibrierung mit einem Muster zu einer Muster-Sensoreinrichtung gepaart ist,
• 11b die Sensoreinheit (Sekundärsensor) im Einbauzustand in ein Aktuatorgehäuse (Hohlwelle) in vereinfachter schematischer Darstellung zwecks Lastkalibrierung,
• 12 ein Kalibrierfenster, das in vereinfachter Darstellung wesentliche Einflussgrößen der Sensoreinrichtung wiedergibt.

The invention is explained in more detail below with reference to the accompanying drawing. This also results in further features and advantageous effects of the invention. In the drawing shows:

• 1 an actively adjustable roll stabilizer of a motor vehicle, in cooperation with opposing wheel suspensions on the right and left side of the vehicle in a schematic view,
• 2 an actuator of an adjustable roll stabilizer with a sensor device for detecting torque in a simplified schematic representation,
• 3 one on one as in 2 The sensor device used in the actuator is shown in an axial section of the actuator in a schematically simplified representation,
• 4 a sensor unit of a sensor device in a perspective view from the radially oblique outside,
• 5 the sensor device according to 4 in a perspective sectional view, diagonally from the side,
• 6 the sensor unit of the 4 and 5 , arranged in the actuator housing (hollow shaft) of an actuator in axial section, with other elements of the actuator being omitted for reasons of illustration,
• 7 the sensor unit (secondary sensor) arranged in the actuator housing (hollow shaft) in the arrangement state as in 6 in a perspective view from diagonally above,
• 8th the sensor unit in an alternative perspective view from the radial outside,
• 9 the sensor unit in a perspective view diagonally from the side,
• 10 the sensor unit in top view,
• 11 a a sensor unit (secondary sensor) which is paired with a pattern to form a pattern sensor device for the purpose of temperature calibration,
• 11b the sensor unit (secondary sensor) when installed in an actuator housing (hollow shaft) in a simplified schematic representation for the purpose of load calibration,
• 12 a calibration window that shows the essential influencing variables of the sensor device in a simplified representation.

To illustrate the area of application of the invention shows 1 First, an actively adjustable roll stabilizer 1 for a motor vehicle in a simplified, schematic, perspective view. The adjustable roll stabilizer 1 is part of a not completely shown chassis of a motor vehicle (not shown). A left wheel 7a and a right wheel 7b arranged on the opposite side of the vehicle are each connected to the body of the motor vehicle via a wheel suspension 8a and 8b (shown in simplified form). The left wheel 7a and the associated wheel suspension 8a or the right wheel 7b and the associated wheel suspension 8b are each coupled to an outer end of an associated stabilizer section 6a or 6b of the actively adjustable roll stabilizer 1. The two stabilizer sections 6a and 6b are connected to one another in the center of the vehicle via an actuator 2 - shown in simplified form as a substantially cylindrical body.

In a manner known per se, the adjustable roll stabilizer 1 is mounted so that it can rotate relative to the vehicle body about an axis of rotation 3 (mounting not shown in more detail). The actuator 2, shown in simplified form as a cylindrical body, essentially comprises an actuator housing 4 which is essentially rotationally symmetrical with respect to the axis of rotation 3 and which is designed at least in some areas as a hollow shaft and acts accordingly.

In the actuator housing 4, among other things, an electric motor 15 and a multi-stage planetary gear 16 are arranged; see below 2 referred to, the one as in 1 shows the actuator 2 used in a schematic side view, the approximate position of the electric motor 15 and gear 16 being indicated by arrows. The stabilizer sections 6a and 6b are in drive connection via part of the actuator housing 4, the electric motor 15 and the multi-stage planetary gear 16 arranged coaxially therewith connection to each other. When the electric motor 15 is stationary, the two stabilizer sections 6a, 6b are rigidly connected to one another via the actuator 2. By rotating the electric motor 15, the stabilizer sections 6a, 6b can be rotated relative to one another about the axis of rotation 3 depending on the direction of rotation. This is how the adjustable roll stabilizer 1 can be adjusted according to 1 Adjust in a manner known per se, which makes it possible to influence the roll behavior of a motor vehicle equipped with the roll stabilizer 1.

According to the schematic representation shown, the stabilizer section 6a is fixed to the housing, ie it is connected to one end 5a of the actuator housing 4 in a rotationally fixed manner. On the other hand, the stabilizer section 6b is connected to the actuator 2 at its output end 5b. That is, the stabilizer section 6b is rotatably mounted relative to the actuator housing 4, but at the same time is drive-connected to the transmission output of the actuator 2. Depending on the operating state of the motor vehicle equipped with the roll stabilizer 1, a torque M acts between the stabilizer sections 6a, 6b, which is in 1 is referred to as a double arrow acting around the axis of rotation 3. The strength and direction of the torque M depend on the respective operating state.

The in 2 Actuator 2 shown, which is part of a as in 1 schematically shown adjustable roll stabilizer 1, is further provided with a control 14, which - like the electric motor 15 and the multi-stage planetary gear 16 - is located within the actuator housing 4 in an area of the actuator housing facing the stabilizer section 6a fixed to the housing. The controller 14 includes, among other things, electrical and/or electronic components, among other things for controlling and powering the electric motor 15. Furthermore, a sensor device 10 is arranged in this area of the actuator housing 4, which works according to the principle of active inverse magnetostriction and with which a Torque M acting on the actuator 2 about the axis of rotation can be recorded and measured.

In 2 For reasons of simplification, the stabilizer sections 6a, 6b are shortened and shown in simplified form as stubs extending along the axis of rotation 3. The actuator 2 located between these, which connects the stabilizer sections 6a and 6b to one another (see Fig. 1 ), has an electric motor 15 and a coaxially arranged multi-stage planetary gear 16, which are arranged together with the controller 14 within the actuator housing 4. As already in connection with 1 explained, the stabilizer section 6a is connected in a rotationally fixed manner to the actuator housing 4, while the stabilizer section 6b is rotatably mounted relative to the actuator housing 4 and is connected in a rotationally fixed manner to the output of the multi-stage planetary gear 16 in order to move relative to the (fixed to the housing) by means of the electric motor 15 and the gear 16. Stabilizer section 6a to be rotatable. The housing-fixed end 5a of the actuator is therefore connected to the stabilizer section 6a, while at the output end 5b of the actuator the stabilizer section 6b is rotatably mounted relative to the actuator housing 4 and is in drive connection at least with the multi-stage planetary gear 16 and the electric motor 15. Alternatively or additionally, further or other elements could also be present in the drive train formed in this way, for example a clutch, brake, a spring and/or damping device.

The sensor device 10 of the actuator 2 essentially comprises a primary sensor and a secondary sensor. An axial section of the actuator housing 4, which is located between the electric motor 15 and the housing-fixed end of the actuator 5a, is made of a magnetizable material. According to the physical effect of inverse magnetostriction, ie a change in magnetization due to mechanical stresses, this region of the actuator housing 4, which is designed as a hollow shaft and which transmits the torque M between the stabilizer sections 6a and 6b, can be used as a primary sensor. For this purpose, a sensor unit 11 is further arranged within the actuator housing 4, which acts as a so-called secondary sensor, as in 3 shown schematically.

Based on 3 , which is an axial section through the actuator 2 2 in the area of the sensor unit 11 shows schematically, the functioning of the sensor device 10 is explained: Within the essentially rotationally symmetrical actuator housing 4 is a sensor unit 11 (secondary sensor) near the housing wall of the actuator housing 4, so in particular radially within a section of the actuator housing 4 serving as a primary sensor ( hollow shaft). The sensor unit 11 has a curved sensor head facing the inner wall of the actuator housing 4 (hollow shaft), which is equipped with a transmitter coil 12 and several receiver coils 13. By means of the transmitter coil 12 arranged on the sensor unit 11, a region of the actuator housing 4 in its vicinity (specially treated hollow shaft section of the actuator housing 4) can be actively magnetized. The magnetic response of the primary sensor is detected by means of the receiver coils 13 of the sensor unit 11 (secondary sensor).

If there is a torque M on the actuator housing 4, as in 3 indicated by the curved double arrow, the mechanical stresses caused in the material of the actuator housing 4 - according to the principle of inverse magnetostriction - cause the hollow shaft to transform the mechanical torque load (the torque M) into measurable changes in its magnetic properties. The design and material selection of the hollow shaft ensures linearity and accuracy over its service life. The change in the magnetic properties is detected via the receiver coils 13. Thus, the sensor device 10 can detect and measure (determine the direction and height) a torque M acting on the actuator housing 4 (hollow shaft) of the actuator 2 through the interaction of the primary sensor and secondary sensor.

Based on the following 4 , 5 and 6 to 10, explanations regarding the structural design of the sensor device 10 are made using an exemplary embodiment, which is described below in different aspects. Since the figures mentioned refer to the same exemplary embodiment, the following description of the exemplary embodiment applies equally to all of the figures mentioned.

The 4 , 5 and 6 to 10 show a sensor unit 11 according to one and the same exemplary embodiment in different views, the sensor unit 11 being shown by itself in these figures. On the other hand, they show 6 and 7 the sensor unit 11 is installed in a hollow shaft section of the actuator housing 4 (installed state). For illustration and clear presentation are in the 6 and 7 In addition to the sensor unit 11 and the hollow shaft section of the actuator housing 4, other parts and components of an actuator are omitted. It is understood that in the 6 and 7 illustrated section of the actuator housing 4 part of one as based on 2 or. 1 shown actuator of a roll stabilizer can be.

First of all, the following is based on the 4 , 5 and 6 to 10 the sensor unit 11 is described with regard to its structure. As essential elements, the sensor unit 11 therefore has a sensor housing 23, a coil board 22, and a coil carrier board 18 (in the sectional view according to 6 and 7 designated), an electronic board 17 and a cage tab 25. The sensor housing 23 is a trough-shaped plastic part with a radially outwardly curved underside. The curvature of the underside is selected such that the sensor housing 23 essentially follows the curvature of the inner wall of the actuator housing 4 when installed in the actuator housing 4 (hollow shaft).

Like in the 4 , 8th and 9 shown, four support pads 27 are formed on the underside of the sensor housing 23, which protrude radially from the curved plane of the underside of the sensor housing 23. When installed in the actuator housing 4 (see 6 and 7 ), the sensor housing 23 contacts the actuator housing 4 exclusively via the four support pads 27. In this way it is ensured that the sensor housing 23 assumes a defined relative position relative to the actuator housing 4 (hence the primary sensor), which remains unchanged over the operating period of the actuator 2.

On the underside of the sensor housing 23 are, for example in 4 can be seen, two housing slots 28 are formed. Each of the housing slots 28 extends parallel to the axis of rotation 3 (based on the installed state in the actuator housing 4), thus orthogonal to the direction of curvature of the underside of the sensor housing 23.

In the sensor housing 23 is, as best in the 6 and 7 can be seen, a coil carrier board 18 arranged in the bottom area. It is a flat, rectangular component that is held in position relative to the sensor housing 23 via four retaining pins 21, each of the four retaining pins 21 protruding through a hole 20 formed in the coil carrier board 18. Accordingly, the coil carrier board 18 is locked in the plane in four areas relative to the sensor housing 23.

On the underside, the coil carrier board 18 rests on the sensor housing 23, at least in its outer areas, as shown in 6 can be seen, which ensures that the coil carrier board 18 is held at a defined distance from the sensor housing 23 and thus at a defined distance and close to the actuator housing 4.

Below the coil carrier board 18, the coil board 22 is arranged, which is attached to the coil carrier board 18. On the coil board 22 there is an arrangement of sensor coils - not visible here - comprising at least one transmitter coil and one receiver coil (see explanation for 3 ). Because the coil board 22 is attached to the coil carrier board 18, the transmitter and receiver coils arranged on the coil board 22 are also in a defined position relative to the actuator housing 4. The relative position of the coil board 22 relative to the actuator housing 4 is for the reliability and accuracy of the sensor device 10 is very important.

As in 4 As can be seen, the coil board 22 protrudes in opposite areas into the two housings formed on the sensor housing 23 slots 28 in so that these - as in 4 shown - becomes partially visible from below.

As in 5 As can be seen, a large number of contact pins 19 are formed on the coil carrier board 18, which in the exemplary embodiment shown protrude in two rows parallel to one another orthogonally from the coil carrier board 18 in the direction of the electronic board 17 and penetrate it. The contact pins 19 serve to establish electrically necessary contacts between the coil carrier board 18 or the coil board 22 arranged thereon and electronic circuits located on the electronic board 17. The individual pins 19 penetrate the electronic board 17, in particular without forming a rigid mechanical connection to the electronic board 17. This ensures in particular that there is a certain mechanical decoupling between the coil board 22 and the electronic board 17. In this way, it is avoided that, for example, changes in position of the electronic board 17, which can be caused in particular by temperature influences or other disruptive influences, influence the relative position of the coil board 22 relative to the actuator housing 4, which would lead to a deterioration in the accuracy of the sensor device. The electrical connection between pins 19 and circuits on the electronic board 17 is established in a manner to be explained.

Like in the 4, 6 to 10 As can be seen, a so-called cage tab 25 is also assigned to the sensor housing 23. The cage tab 25 contributes significantly to holding the sensor housing 23 in a defined relative position relative to the actuator housing 4 (hollow shaft), particularly over the lifespan of the sensor device 10. The cage tab 25 is a metallic molded part which surrounds the sensor housing 23 like a frame. The cage tab has resilient properties, in particular it is inherently resiliently deformable. The cage tab 25 has two brackets 33, 34 that run parallel to one another and each end at a front connecting web 35 and a rear connecting web 36, respectively. The front and rear connecting webs 35, 36 also run parallel to each other, orthogonal to the two brackets 33, 34. An approximately teardrop-shaped soldering surface 26 is formed on the front connecting web 35, which protrudes forward from the cage tab 25, and there is a corresponding one on the rear bracket rear-facing drop-shaped soldering surface 26 is formed. The terms “front” and “rear” in this context refer to the circumferential extent of the sensor housing 23.

Like that 4 , 8th , 9 and 10 As can be seen, the brackets 33, 34 of the cage tab 25 run laterally from the sensor housing 23, while the connecting webs 35, 36 run transversely parallel to the end faces of the sensor housing 23, see in particular 10 .

As in 9 As can be seen, the brackets 33, 34 of the cage tab 25 are supported in their central areas on a shoulder 31 formed on the sensor housing 23. A radially outwardly acting force can be exerted on the sensor housing 23 by the cage tab 25 via the shoulder 31. A radially inward-pointing projection in the form of a holding arm 32 formed on the shoulder 31 prevents the bracket 33, 34 of the cage tab 25 from slipping laterally outwards from the shoulder 31.

Regarding 10 It can be seen that a total of eight fitting lugs 24 are formed on the sensor housing 23 in the exemplary embodiment shown. Of these, four fitting lugs 24 point forwards or backwards (tangential direction) from the sensor housing 23, while four further fitting lugs 24 protrude from the sensor housing 23 in the lateral direction (in opposite axial directions). The sensor housing 23 rests in the tangential direction and in the axial direction on the cage tab 25 only in the contact points specified by the eight fitting lugs 24. In this way it is ensured that the relative position of the sensor housing 23 relative to the actuator housing 4 after assembly is as decoupled as possible from possible deformations (thermal or mechanical) or other disruptive influences that could affect the relative position of the sensor housing 23 relative to the actuator housing 4. The fitting lugs 24 are advantageously cut to size and/or abraded during assembly due to the deflection of the cage tab 25, so that a play-free connection is created (at room temperature equal to the assembly temperature).

To attach the sensor unit 11 to the actuator housing 4, the sensor unit 11 including the cage tab 25 is inserted into the actuator housing 4, as shown in FIG 6 and 7 shown. The four support pads 27 formed on the underside of the sensor housing 23 ensure that the coil board 22 in particular assumes a defined relative position relative to the actuator housing 4.

To attach the sensor unit 11 to the actuator housing 4, the cage tab 25 is pressed downwards, that is to say radially outwards, in the area of the two projecting soldering surfaces 26 (and thus slightly elastically deformed) and then soldered to the inner wall of the actuator housing 4, i.e. in a cohesive manner with it tied together. It should be mentioned that the cage tab 25 can also be cohesively bonded to the actuator in an alternative manner Housing 4 can be connected, in particular by a welded connection, preferably by resistance spot welding.

Due to the previous slight elastic deformation, the cage tab 25 in its deformed state in the area of the brackets 33, 34 exerts a restoring force on the shoulders 31 of the sensor housing 23, so that the entire sensor housing 23 corresponds to that in 9 arrows shown is permanently pressed against the wall of the actuator housing 4. The flow of force from the resilient cage tab 25 to the sensor housing 23 is optimized in such a way that the support pads 27 (contact areas to the actuator housing 4) are each approximately below the level caused by the in 9 Force introduction points indicated by force arrows are arranged, so that the electronics, the coil carrier and the coil board are largely kept out of the flow of force. Due to the contact of the sensor housing 23 exclusively via the four support pads 27 on the actuator housing 4, a frictional and non-positive connection is created, which ensures permanent positioning of the sensor housing 23.

According to the in 5 As can be seen in the design of the sensor unit 11, some of which have already been explained previously, the electronic board 17 is largely mechanically decoupled from the coil carrier board 18 or the coil board 22. In this context, it should be mentioned that during operational use of the sensor unit 11, there is heating and thus thermally caused expansion of the sensor unit 11 Electronic board 17 can come. Other components such as the housing 23, the pins 19, the coil carrier board 18, the coil board 22, the cage tab 25 can also heat up (or cool down) due to operation. The structure described ensures that, in particular, thermal changes in length in the board level (electronic board 17) can be compensated for. A relative position of the coil board 22 relative to the actuator housing 4 that was initially assumed when the sensor unit 11 was installed can therefore be maintained largely unchanged over the operating period.

As described with reference to the previous figures, and especially in the 6 and 7 shown, the coil carrier board 18, which is connected to the coil board 22 in order to hold it in a defined relative position relative to the actuator housing 4, is locked relative to the sensor housing 23 via 4 retaining pins 21. The retaining pins 21 each penetrate holes 20 formed in the coil carrier board 18.

With the sensor device 10 used on the actuator 2, which works according to the principle of inverse magnetostriction, a torque M acting on the actuator 2 can be detected. In order to achieve the required accuracy of the sensor device 10, a calibration of the sensor device 10 is necessary. The main influencing factors are temperature and load (acting torque M) on the measurement result of the sensor device 10. These are expediently determined as part of a calibration as part of the manufacturing process of the actuator 2. Further influencing variables on the measurement result of the sensor device result in particular from the specific assembly of the sensor device on a specific actuator. These influences include, among others, the relative position of the sensor unit (secondary sensor) relative to the primary sensor (hollow shaft or actuator housing), the actuator housing (hollow shaft) itself, assembly influences (mainly the joining of the actuator housing or hollow shaft with neighboring parts) and magnetization.

In order to achieve the desired accuracy of the sensor device, a calibration scheme is carried out as part of the production of an actuator, which is optimized for low handling effort.

An actuator is manufactured in such a way that a sensor unit 11 (secondary sensor) is first produced. This has a sensor housing 23 which accommodates a coil arrangement 12, 13.

As in 11a shown, this sensor unit 11 is then brought together with a pattern 30 similar to the primary sensor of the actuator 2 to form a pattern sensor device 37. For this purpose, the sensor unit 11 is arranged on the pattern 30 in such a way that the sensor unit 11 assumes a defined relative position relative to the pattern 30 (replicating the later contact pressure situation in the installed state on the actuator).

The sample 30 is a test component that is only used for calibration purposes, in particular in the form of a segment of a hollow shaft. With respect to the sensor unit 11, the pattern 30 has a magnetostrictive behavior under the influence of temperature that is comparable to the actuator housing 4. In particular, the pattern 30 is therefore representative of the actuator housing 4 in the (later) installed state on the actuator 2. In comparison, however, the pattern 30 can have smaller dimensions and can therefore be designed to be easier to handle.

In the 11 a The sample sensor device 37 shown consisting of sensor unit 11 and sample 30 is suitable for carrying out a temperature calibration tion. For this purpose, the sample sensor device 37 is heated in an oven while a load-free calibration is carried out on the sensor unit 11 (not shown). In this way, the temperature-dependent behavior of the sensor unit 11 can be determined in a load-free manner in conjunction with the exemplary primary sensor (pattern 30). In particular, a zero position (so-called “offset”) of the sensor unit 11 can be determined in this way. In this first one, as in 12 In the calibration process represented by the temperature bar, only the temperature is changed without the influence of a load (a torque M) in order to map the temperature behavior of the sensor unit 11 or to calibrate it in this regard. Since the sample 30 has small structural dimensions, easy handling of the sample sensor device 37 is ensured during temperature calibration.

After carrying out the temperature calibration, the sensor unit 11 is separated from the sample 30.

To carry out another, based on 11b In the calibration step to be explained, the sensor unit 11 (after temperature calibration has been carried out) is brought together with the actuator housing 4 (hollow shaft) and finally installed in it in order to produce an actuator 2 with a sensor device 10, which is the primary sensor formed at least in some areas by the actuator housing 4 and as a secondary sensor serving sensor unit 11 includes (final assembly state). Accordingly, the sensor unit 11 (secondary sensor) is now paired with the specific, final actuator housing 4 that serves as the primary sensor.

As in 11b indicated by the curved double arrow, the fully assembled actuator 2 is then loaded with torque M, so that the sensor device 10 formed from the sensor unit 11 and the actuator housing 4 undergoes a load calibration. With reference to the in 12 In the calibration window shown, the load behavior of the sensor device is determined in this second calibration step. This load calibration expediently takes place at the end of the manufacturing process of the actuator 2.

By, as by means of 11 a described, the temperature calibration is carried out in pairing with the pattern 30, this can be carried out in an advantageous manner independent of the location of the other production of the actuator. In addition, the pattern 30 is preferably a significantly smaller component than the later actuator housing 4, which results in the advantageous effect that significantly less space has to be made available for the temperature calibration within an oven required for this purpose. The temperature calibration can be carried out in a space-saving and energy-efficient manner with little handling effort.

The calibration processes carried out (temperature calibration and load calibration) make it possible to describe the influences of temperature and load on the sensor device mathematically, in particular using third degree polynomials, including their interaction (cross terms).

The desired behavior, which is independent of temperature influences and linear to the magnitude of the torque - with deviations within the tolerance range - is determined by linearization in the sensor unit using the polynomials mentioned. Their parameters (coefficients) are determined individually for the respective actuator according to a scheme in the various calibration steps described above (temperature calibration, load calibration). Further influences are determined from deviations from the calibration. As a result, a high level of accuracy of the sensor device is achieved in this way with reasonable effort.

Reference symbols

1

Roll stabilizer

2

actuator

3

Axis of rotation

4

Actuator housing (hollow shaft)

5a

end of the actuator fixed to the housing

5b

output end of the actuator

6a

Stabilizer section (fixed to housing)

6b

Stabilizer section (output side)

7a, 7b

wheel

8a, 8b

suspension

10

Sensor device

11

Sensor unit (secondary sensor)

12

Transmitter coil

13

Receiver coil

14

steering

15

Electric motor

16

(multi-stage planetary) gearbox

17

Electronic board

18

Coil carrier board

19

Contact pin

20

Hole

21

retaining pin

22

coil board

23

Sensor housing

24

Pass nose

25

Cage tab

26

soldering area

27

Support pad

28

Housing slot

30

Pattern

31

shoulder

32

Holding arm

33

hanger

34

hanger

35

web

36

web

37

Pattern sensor device

M

Torque

Claims (12)

Method for calibrating a sensor device (10), which is suitable for detecting a torque (M) acting on an actuator (2) of an adjustable roll stabilizer (1) using the principle of inverse magnetostriction, wherein the sensor device (10) carries out an at least partially a primary sensor formed by an actuator housing (4) and a secondary sensor arranged in the actuator housing (4), the method comprising the following steps: a) producing a sensor unit (11) serving as a secondary sensor, comprising a sensor housing (23) which accommodates a coil arrangement (12, 13), b) bringing together the sensor unit (11) with a pattern (30) similar to the primary sensor of the actuator (2) to form a pattern sensor device (37), c) carrying out a temperature calibration of the pattern sensor device (37), d) separating the sensor unit (11) from the pattern (30), e) bringing together the sensor unit (11) with the actuator housing (4) in order to produce an actuator (2) with a sensor device (10) which has the primary sensor formed at least in some areas by the actuator housing (4) and the sensor unit (11) serving as a secondary sensor. includes, f) Carrying out a load calibration of the sensor device (10). Procedure according to Claim 1 , characterized in that while carrying out the temperature calibration, the sample sensor device (37) is exposed to different temperatures in the mechanically unloaded state. Method according to one of the preceding claims, characterized in that only the temperature is changed while carrying out the temperature calibration. Method according to one of the preceding claims, characterized in that the temperature calibration serves to determine a zero position and/or offsets of the pattern sensor device (37). Method according to one of the preceding claims, characterized in that in the step of carrying out the load calibration, the actuator (2) is subjected to different torques (M) at a normal temperature. Method according to one of the preceding claims, characterized in that only the torque load (M) of the actuator (2) is changed during the load calibration. Method according to one of the preceding claims, characterized in that the calibration data recorded in each case is recorded while the temperature calibration and/or load calibration is being carried out. Method according to one of the preceding claims, characterized in that, on the basis of the calibrations, a behavior of the sensor device (10) that characterizes the actuator (2), in particular a relationship between temperature and load influence that applies to the specific sensor device (10), is determined and assigned to it , in particular is stored in an electronic control unit associated with the actuator (2). Method according to one of the preceding claims, characterized in that the pattern (30) is a component serving the purpose of temperature calibration, which is preferably modeled on a segment of the actuator housing (4) and/or at least one of the actuator housing (4). has comparable magnetostrictive behavior under the influence of temperature. Method according to one of the preceding claims, characterized in that further steps in the production of the actuator (2) take place in connection with the bringing together of the sensor unit (11) with the actuator housing (4), such as in particular connecting the sensor unit (11) to the actuator housing (4), closing the actuator housing (4) and the like. Pattern (30) for calibrating a sensor device as part of a calibration method according to one of the preceding claims, which can be brought together with the sensor unit (11) to form a pattern sensor device (37) and has a magnetostrictive behavior under the influence of temperature that is comparable to the actuator housing (4). Pattern (30). Claim 11 , characterized in that this is modeled on a segment of the actuator housing (4).

Images