DE102019120468A1 - Arrangement for measuring a force or a moment and method for testing the arrangement - Google Patents

Abstract

The invention relates to a method for testing an arrangement for measuring a force and / or a moment (Mt) on a machine element (01) extending in an axis (03), the measurement taking place using the inverse magnetostrictive effect. The machine element (01) has at least two magnetization areas (04) extending circumferentially around the axis (03). The arrangement comprises at least four magnetic field sensors (06) for measuring an axial component of a magnetic field caused by the magnetization and by the force or by the moment (Mt). There are at least two combinations of at least two of the magnetic field sensors (06) each, each of which is sufficient to measure the force or the moment (Mt). According to the method, a first correction factor for calibrating a first one of the combinations and a second correction factor for calibrating a second one of the combinations are determined. A first measured value of the force or the moment (Mt) is determined with the first combination. The first correction factor is applied to the first measured value in order to obtain a first corrected measured value. Furthermore, a second measured value of the force or the moment (Mt) is determined with the second combination. The second correction factor is applied to the second measured value in order to obtain a second corrected measured value. According to the invention, the first corrected measured value and the second corrected measured value are compared. The invention also relates to an arrangement for measuring a force and / or a moment (Mt).

Description

The present invention relates initially to a method for testing an arrangement for measuring a force and / or a moment on a machine element extending in an axis, the force or moment being measured using the inverse magnetostrictive effect. The machine element has at least two magnetization areas extending circumferentially around the axis, which form a primary sensor for the measurement. The arrangement comprises at least four magnetic field sensors as secondary sensors. The method allows a malfunction of the arrangement to be identified. The invention also relates to an arrangement for measuring a force and / or a moment on a machine element.

The US 6,490,934 B2 teaches a magnetoelastic torque sensor for measuring a torque which acts on an element with a ferromagnetic, magnetostrictive and magnetoelastically active area. This area is formed in a transducer that sits as a cylindrical sleeve, for example on a shaft. The torque sensor faces the transducer.

From the EP 0 803 053 B1 a torque sensor is known which comprises a magnetoelastic transducer. The transducer sits on a shaft as a cylindrical sleeve.

The US 8,893,562 B2 Fig. 10 shows a method of detecting magnetic noise in a magnetoelastic torque sensor. The torque sensor comprises a torque converter with oppositely polarized magnetizations and several magnetic field sensors, between which it can be switched.

The US 8,578,794 B2 teaches a magnetoelastic torque sensor having a longitudinally extending member and having multiple magnetoelastically active regions and having primary and secondary magnetic field sensors that are axially spaced.

From the US 2014/0360285 A1 a magnetoelastic torque sensor is known which includes a hollow longitudinally extending member having a plurality of magnetoelastically active regions. Primary and secondary magnetic field sensors are located in the hollow element.

From the US 8,087,304 B2 a magnetoelastic torque sensor is known which comprises a longitudinally extending element with a plurality of magnetoelastically active regions. The torque sensor comprises primary and secondary magnetic field sensors which are connected as a Wheatstone bridge.

The US 2004/0154412 A1 shows a sensor for measuring diverging magnetic fields emerging from a magnetoelastic wave. The shaft has two magnetization areas, each of which is assigned two coils for measuring the magnetic fields.

The US 2014/0360285 A1 teaches a magneto-elastic torque sensor with which a torque acting on a hollow shaft can be measured. The hollow shaft has three circumferentially magnetized magnetization areas with alternating polarities. Four secondary magnetic field sensors are arranged opposite the magnetization areas.

From the US 9,151,686 B2 a magnetoelastic torque sensor is known which is said to have a reduced signal noise. The torque sensor comprises a hollow shaft with three circumferentially magnetized magnetization areas which have alternating polarities. Up to eight magnetic field sensors are arranged opposite the magnetization areas.

The DE 10 2015 209 286 A1 shows an arrangement and a method for measuring a force and / or a moment on a machine element using the inverse magnetostrictive effect. The machine element has at least one magnetization area for magnetization. At least two spaced apart magnetic field sensors are used to measure a magnetic field caused by the magnetization and by the force and / or the moment. According to the method, the measurement signals from the magnetic field sensors are processed individually.

Based on the prior art, the object of the present invention is to be able to better recognize malfunctions in a measurement of forces and / or moments based on the inverse magnetostrictive effect, in order to be able to meet higher requirements in the field of functional safety, for example. The disruptive influence of static interference fields, such as the earth's magnetic field, and also the disruptive influence of dynamic interference fields, such as the interference field of a neighboring electric drive, should be recognizable.

The stated object is achieved by a method according to the attached claim 1 and by an arrangement according to the attached independent claim 10.

The method according to the invention is used to test an arrangement which is designed to measure a force and / or a moment on a machine element extending in an axis. With the method, correct functioning of the arrangement is monitored and a malfunction of the arrangement that occurs can be recognized.

The force or the moment acts on the machine element of the arrangement, as a result of which mechanical stresses occur and the machine element is usually slightly deformed. The axis preferably forms an axis of rotation of the machine element. The directions given below, namely the axial direction, the radial direction and the tangential or circumferential direction, are related to said axis. The arrangement is preferably designed to measure a moment that lies in the axis, so that it is a torsional moment by which the machine element is loaded. The vector of the moment lies in the axis. The arrangement is preferably also designed for measuring a transverse force which is oriented perpendicular to the axis. The transverse force and the axis are preferably in one plane.

The machine element has at least two magnetization areas extending circumferentially around the axis, each for a magnetization formed in the machine element. There are thus at least two magnetization areas that run around the axis, i. H. around circular magnetization areas, the axis itself preferably not forming part of the magnetization areas. The magnetization areas preferably only have a tangential alignment with respect to a surface of the machine element extending around the axis. The magnetization areas preferably each extend along a closed path around the axis, wherein the magnetization areas may have short gaps. The magnetization areas preferably have the same spatial extent and are axially spaced. The magnetization areas are particularly preferably designed in the form of magnetization tracks. The magnetization areas each form a primary sensor for determining the force or the moment.

The machine element preferably also has magnetically neutral areas which are each arranged axially between the magnetization areas and / or axially next to the magnetization areas of the machine element. The machine element preferably has at least one of the magnetically neutral areas. The magnetically neutral areas neither have permanent magnetization, nor is the arrangement designed to temporarily magnetize the magnetically neutral areas. The magnetically neutral areas are preferably not magnetized. The magnetically neutral areas are preferably each formed in an axial section of the machine element.

The arrangement further comprises at least four magnetic field sensors, each of which forms a secondary sensor for determining the force or the moment. The primary sensors, i.e. H. the magnetization areas are used to convert the force to be measured or the moment to be measured into a corresponding magnetic field, while the secondary sensors enable this magnetic field to be converted into electrical signals. The magnetic field sensors are each designed for the individual measurement of an axially aligned directional component of a magnetic field caused by the magnetization and by the force and / or by the moment. The mentioned magnetic field occurs due to the inverse magnetostrictive effect. Thus, the measurement possible with the arrangement is based on the inverse magnetostrictive effect.

There are at least two different combinations of at least two of the magnetic field sensors, each of these combinations being sufficient for measuring the force or the moment. The at least two combinations are therefore redundant in terms of their suitability for measuring the measurement of the same force or the same moment. The combinations are to be understood in terms of combinatorics and each represent a selection of at least two of the magnetic field sensors, the combinations being able to include different numbers of the magnetic field sensors and one of the combinations being able to be formed by all of the magnetic field sensors. At least two different combinations can be selected from the at least four magnetic field sensors, each of which is suitable for measuring the force or the moment. Particularly preferably there are at least three of the combinations of at least two of the magnetic field sensors, each of these combinations being sufficient to measure the force or the moment.

The magnetic field sensors are arranged opposite the machine element, there being preferably only a small radial distance between the magnetic field sensors and an inner or outer surface of the machine element. The magnetic field sensors are preferably at the same distance from the axis.

In one step of the method, a first correction factor for calibrating a first one of the combinations of magnetic field sensors is determined. The first correction factor is used to correct a measured value, which is determined from measurement signals from the individual magnetic field sensors belonging to the first combination.

In a further step of the method, a second correction factor for calibrating a second one of the combinations of magnetic field sensors is determined. The second correction factor is used to correct a measured value, which is determined from measurement signals from the individual magnetic field sensors belonging to the second combination.

In a further step of the method according to the invention, a first measured value of the force or the moment is determined with the first combination of the magnetic field sensors while the force or the moment is acting. The first measured value is determined from measurement signals from the individual magnetic field sensors belonging to the first combination.

In a further step of the method according to the invention, a second measured value of the force or the moment is determined with the second combination of the magnetic field sensors while the force or the moment is acting. The second measured value is determined from measurement signals from the individual magnetic field sensors belonging to the second combination.

The determination of the first measured value and the determination of the second measured value preferably take place simultaneously or at least within a time span in which the force or the moment does not change. The measured values represent qualitatively and quantitatively the same force or the same moment. The measured values can each have an error due to static and / or dynamic interference fields.

The first correction factor is applied to the first measured value in order to obtain a first corrected measured value. The second correction factor is applied to the second measured value in order to obtain a second corrected measured value.

Since the first combination of the magnetic field sensors and the second combination of the magnetic field sensors are each sufficient for measuring the force or the moment, the first corrected measured value and the second corrected measured value are the same if the arrangement is working correctly. According to the invention, the first corrected measured value is compared with the second corrected measured value, so that an error-free function or an incorrect function of the arrangement can be concluded from the result of this comparison. If the comparison concludes that the arrangement is functioning incorrectly, it is preferably also determined which of the individual magnetic field sensors has an incorrect function.

A particular advantage of the method according to the invention is that the result of the comparison of the corrected measured values provides a largely reliable statement as to whether the arrangement is working correctly or incorrectly.

The at least two magnetization areas can be magnetized permanently or temporarily. The magnetization areas are preferably permanently magnetized, so that the magnetization is formed by permanent magnetization. Alternatively, the arrangement also preferably has at least one magnet for magnetizing the magnetization areas, so that the magnetization of the magnetization areas is basically temporary. The at least one magnet can be formed by a permanent magnet or preferably by an electromagnet.

The permanently or temporarily magnetized magnetization areas are preferably magnetically neutral outside the magnetization areas when the machine element is unloaded by a force or moment, so that no technically relevant magnetic field can be measured outside the magnetization areas.

The magnetization areas each represent part of the volume of the machine element. The magnetization areas are preferably each ring-shaped, the axis of the machine element also forming a central axis of the respective ring shape. The magnetization areas particularly preferably each have the shape of a hollow cylinder coaxial with the axis of the machine element.

The magnetization areas preferably each have a high magnetostrictivity.

The magnetization regions are preferably arranged axially spaced from one another, it being possible for one of the magnetically neutral regions to be arranged between two adjacent magnetization regions. If more than two of the magnetization areas are present, they are preferably each at the same distance from one another.

Axially adjacent ones of the magnetization areas extending circumferentially around the axis preferably have opposite polarities, i. H. they have an opposite sense of rotation.

The machine element consists of a magnetostrictive or magnetoelastic material at least in the magnetization area. The machine element preferably consists entirely of the magnetostrictive or magnetoelastic material. The machine element preferably consists of a steel.

The machine element preferably has the shape of a prism or a cylinder, the prism or the cylinder being arranged coaxially to the axis. The prism or the cylinder is preferably straight. The machine element preferably has the shape of a straight circular cylinder, the circular cylinder being arranged coaxially to the axis. In particular embodiments, the prism or the cylinder is conical. The prism or the cylinder can also be hollow. The machine element particularly preferably has the shape of a straight, hollow circular cylinder, the hollow circular cylinder being arranged coaxially to the axis.

The machine element is preferably formed by a shaft, by a hollow shaft, by a shift fork, by a flange or by a hollow flange. The shaft, the shift fork or the flange can be designed for loads from different forces and moments and, for example, be a component of a sensor bottom bracket, a roll stabilizer or a fertilizer spreader. In principle, the machine element can also be formed by completely different types of machine element.

The magnetic field sensors are preferably each formed by a semiconductor sensor. The at least two magnetic field sensors are alternatively preferably each formed by an MR sensor, a Hall sensor, a field plate, a SQUID, a coil element, a Förster probe or a fluxgate magnetometer. In principle, other types of sensors can also be used, provided they are suitable for measuring the axial directional component of the magnetic field caused by the inverse magnetostrictive effect.

The magnetic field sensors are preferably at the same distance from the axis of the machine element. In principle, the magnetic field sensors can be arranged outside the machine element or preferably also inside a cavity of the machine element; for example if the machine element is formed by a hollow shaft or by a hollow flange.

The magnetic field sensors preferably each have an axial position like one of the magnetization areas. The magnetic field sensors preferably each have an axial position which is similar to a mean axial position of one of the magnetization areas.

The magnetic field sensors preferably each have the same tangential or the same circumferential position as at least one other of the magnetic field sensors. These at least two magnetic field sensors preferably lie together on a straight line parallel to the axis. These at least two magnetic field sensors having the same tangential or the same circumferential position are axially adjacent and preferably each have the same axial position as axially adjacent ones of the magnetization areas. It is also possible for two magnetic field sensors having the same tangential or the same circumferential position to have the same axial position as only one of the magnetization regions.

At least one of the magnetization areas preferably has the same axial position as at least two of the magnetic field sensors, so that two of the magnetic field sensors are assigned to this magnetization area. These two magnetic field sensors having the same axial position are preferably arranged opposite one another with respect to the axis, so that they have a central angle of 180 ° to one another and a straight line intersecting the two magnetic field sensors intersects the axis perpendicularly. More preferably, each of the magnetization areas has the same axial position as two of the magnetic field sensors, so that at least two of the magnetic field sensors are assigned to each of the magnetization areas.

The arrangement preferably further comprises a measurement signal processing unit which is designed to determine and compare the corrected measurement values. The magnetic field sensors are preferably individually electrically connected to the measurement signal processing unit, so that in each case a single measurement signal is passed from each of the magnetic field sensors to the measurement signal processing unit. Preferred embodiments of the method according to the invention include a step in which the magnetic field sensors are individually calibrated. As a result, an offset can be compensated and the sensitivity of the magnetic field sensors can be compared to one another, so that the reliability of the error detection is increased again.

At least three of the corrected measured values are particularly preferably determined and compared with one another. Accordingly, there are preferably at least three of the combinations of at least two of the magnetic field sensors, each of these combinations being sufficient for measuring the force or the moment. A third correction factor for calibration is determined a third of the combinations of the magnetic field sensors. In addition, a third measured value of the force or the moment is determined with the third combination of the magnetic field sensors while the force or the moment is acting. The first corrected measured value, the second corrected measured value and the third corrected measured value are compared with one another.

At least four of the corrected measured values are furthermore preferably determined and compared with one another. Those embodiments in which three or more of the corrected measured values are determined and compared preferably include a further step in which, in the event of deviations between the corrected measured values, the one or those of the magnetic field sensors that are not working correctly are determined. In addition, it can be determined if one of the magnetization areas has a faulty function.

In preferred embodiments of the method according to the invention, the first correction factor and the second correction factor as well as any additional correction factors are used before the arrangement is used as intended, e.g. B. determined during the manufacture of the arrangement. The first correction factor and the second correction factor as well as any further correction factors are preferably stored in the measurement signal processing unit in order to be able to be used for correcting the measurement values during the later intended use of the arrangement. The determination and correction of the measured values and the comparison of the corrected measured values are preferably carried out during the intended use of the arrangement, i. H. if the machine element is loaded with the force and / or the moment as intended.

The first correction factor is preferably determined in that the machine element is loaded with a reference force and / or with a reference torque and a measured value is measured with the first combination of the magnetic field sensors. The amount of the reference force or the reference torque is known, for example, in that the reference force or the reference torque is measured with a reference measuring device. The amount of the reference force or the reference torque is compared with the measured value of the first combination of magnetic field sensors in order to determine the first correction factor therefrom. The first correction factor is preferably formed by a quotient from the measure of the reference force or the reference torque and the measured value of the first combination of the magnetic field sensors.

The second correction factor is preferably determined in that the machine element is loaded with a reference force and / or with a reference torque and a measured value is measured with the second combination of magnetic field sensors. The amount of the reference force or the reference torque is known, for example, in that the reference force or the reference torque is measured with a reference measuring device. The amount of the reference force or the reference torque is compared with the measured value of the second combination of magnetic field sensors in order to determine the second correction factor therefrom. The second correction factor is preferably formed by a quotient from the measure of the reference force or the reference torque and the measured value of the second combination of the magnetic field sensors.

The reference force or the reference torque for determining the first correction factor and the reference force or the reference torque for determining the second correction factor are preferably the same.

The further correction factors, if any, are preferably determined in accordance with the described determination of the first correction factor and the described determination of the second correction factor.

The first correction factor is preferably applied to the first measured value in that the first correction factor is multiplied by the first measured value. The second correction factor is preferably applied to the second measured value in that the second correction factor is multiplied by the second measured value. The application of the possibly further correction factors to the possibly further measured values is preferably carried out in that the respective further correction factor is multiplied by the respective further measured value.

In preferred embodiments of the method according to the invention, a first offset correction value is also determined which, together with the first correction factor, serves to calibrate the first combination of magnetic field sensors. Accordingly, a second offset correction value is also determined which, together with the second correction factor, serves to calibrate the second combination of magnetic field sensors. Correspondingly, a third offset correction value is also determined, if necessary, which, together with the third correction factor, serves to calibrate the third combination of magnetic field sensors. Correspondingly, further offset correction values are determined, if necessary, which are used together with the respective further correction factor for calibrating the respective further combination of the magnetic field sensors. The first offset correction value is applied together with the first correction factor to the first measured value applied to get the first corrected reading. The second offset correction value is applied to the second measured value together with the second correction factor in order to obtain the second corrected measured value. If necessary, the third offset correction value is applied together with the third correction factor to the third measured value in order to obtain the third corrected measured value. If necessary, the further offset correction values are each applied together with the respective further correction factor to the respective further measured value in order to obtain the respective further corrected measured value. The joint application of the respective offset correction value with the respective correction factor to the respective measured value is preferably carried out in that the respective correction factor is multiplied by the respective measured value and the respective offset correction value is added.

In preferred embodiments of the method according to the invention, absolute amounts of the differences between the corrected measured values or squares of the differences between the corrected measured values are formed to compare the corrected measured values. A sum of the absolute amounts of the differences between the corrected measured values or a sum of the squares of the differences between the corrected measured values is preferably formed. The corresponding sum is preferably used as a test signal.

An error signal is preferably output if the sum of the absolute amounts of the differences between the corrected measured values or the sum of the squares of the differences in the differences between the corrected measured values exceeds a previously defined maximum. The maximum extent defines in advance the difference between the corrected measured values and the extent to which the arrangement is regarded as working without errors. The error signal is preferably reported to a higher-level controller or to an operator of the arrangement, so that the higher-level controller or the operator knows that the arrangement is no longer measuring correctly.

$$M_2=\frac{a_1-b_1}{2}$$

$$M_2=\frac{b_2-a_2}{2}$$

In a first particularly preferred embodiment of the method according to the invention, the arrangement is designed to measure a moment acting on the machine element and lying in the axis, ie a torsional moment, and a transverse force acting on the machine element perpendicular to the axis. The machine element has two of the magnetization areas with opposite polarities. Each of the magnetization areas has the same axial position as two of the magnetic field sensors, these two magnetic field sensors having the same axial position being arranged opposite one another with respect to the axis. Two of the four magnetic field sensors each have the same tangential position and are axially adjacent. A first of the four magnetic field sensors outputs a measurement signal a ₁ . The magnetic field sensor opposite the first magnetic field sensor in relation to the axis and having the same axial position as the first magnetic field sensor forms a second of the magnetic field sensors which outputs a measurement signal a ₂ . The measurement signals a ₁ and a ₂ represent the axial directional components of the magnetic field that occurs due to the inverse magnetostrictive effect and has an opposite sense of direction; ie the measurement signals a ₁ and a ₂ represent the axial directional components with different signs. The magnetic field sensor axially adjacent to the first magnetic field sensor and having the same circumferential position as the first magnetic field sensor forms a third of the magnetic field sensors, which outputs a measurement signal b ₁ . The measurement signals a ₁ and b ₁ represent the axial directional components of the magnetic field occurring because of the inverse magnetostrictive effect with the same sense of direction; ie the measurement signals a ₁ and b ₁ represent the axial directional components with the same sign. The magnetic field sensor opposite the third magnetic field sensor in relation to the axis and having the same axial position as the third magnetic field sensor forms a fourth of the magnetic field sensors, which outputs a measurement signal b ₂ . The measurement signals b ₁ and b ₂ represent the axial directional components of the magnetic field that occurs because of the inverse magnetostrictive effect and has an opposite sense of direction; ie the measurement signals b ₁ and b ₂ represent the axial directional components with different signs. At least two of the measured values of the torsional moment are determined according to one of the following mathematical rules: $${\mathrm{M.}}_1=\frac{a_1-a_2-b_1+b_2}{\mathrm{4th}}$$

$${\mathrm{M.}}_2=\frac{a_1-b_1}{2}$$

$${\mathrm{M.}}_2=\frac{b_2-a_2}{2}$$

The mathematical rules show that there are at least three of the combinations of magnetic field sensors that are sufficient to measure the torsional moment. The first combination includes the first, second, third, and fourth magnetic field sensors. The second combination includes the first and the third magnetic field sensor. The third combination includes the second and fourth magnetic field sensors.

$$M_2^{\text{'}}=k_2\cdot M_2=k_2\cdot \frac{a_1-b_1}{2}$$

$$M_3^{\text{'}}=k_3\cdot M_3=k_3\cdot \frac{b_2-a_2}{2}$$

Before the arrangement was used as intended, the first correction factor k ₁ for the first combination of magnetic field sensors, the second correction factor k ₂ for the second combination of magnetic field sensors and the third correction factor k ₃ for the third combination of magnetic field sensors were determined. These correction factors are applied to the measured values by multiplication, whereby the first corrected measured value M ' ₁ , the second corrected measured value M' ₂ , and the third corrected measured value M ' ₃ are obtained: $${\mathrm{M.}}_1^{\text{'}}=k_1\cdot {\mathrm{M.}}_1=k_1\cdot \frac{a_1-a_2-b_1+b_2}{\mathrm{4th}}$$

$${\mathrm{M.}}_2^{\text{'}}=k_2\cdot {\mathrm{M.}}_2=k_2\cdot \frac{a_1-b_1}{2}$$

$${\mathrm{M.}}_3^{\text{'}}=k_3\cdot {\mathrm{M.}}_3=k_3\cdot \frac{b_2-a_2}{2}$$

$$T=\left|M_1^{\text{'}}-M_3^{\text{'}}\right|$$

$$T=\left|M_2^{\text{'}}-M_3^{\text{'}}\right|$$

$$T={\left(M_1^{\text{'}}-M_2^{\text{'}}\right)}^2$$

$$T={\left(M_1^{\text{'}}-M_3^{\text{'}}\right)}^2$$

$$T={\left(M_2^{\text{'}}-M_3^{\text{'}}\right)}^2$$

The test signal T is preferably determined according to one of the following rules: $$T=\left|{\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_2^{\text{'}}\right|$$

$$T=\left|{\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right|$$

$$T=\left|{\mathrm{M.}}_2^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right|$$

$$T={\left({\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_2^{\text{'}}\right)}^2$$

$$T={\left({\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right)}^2$$

$$T={\left({\mathrm{M.}}_2^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right)}^2$$

$$T={\left(M_1^{\text{'}}-M_2^{\text{'}}\right)}^2+{\left(M_1^{\text{'}}-M_3^{\text{'}}\right)}^2+{\left(M_2^{\text{'}}-M_3^{\text{'}}\right)}^2$$

Preferably, not just two, but all of the three corrected measured values M ' ₁ , M' ₂ , and M ' _{3 are} determined. The test signal T is preferably determined according to one of the following rules: $$T=\left|{\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_2^{\text{'}}\right|+\left|{\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right|+\left|{\mathrm{M.}}_2^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right|$$

$$T={\left({\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_2^{\text{'}}\right)}^2+{\left({\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right)}^2+{\left({\mathrm{M.}}_2^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right)}^2$$

$$M_2=\frac{a_1-b_1}{2}$$

$$M_3=\frac{b_2-c_2}{2}$$

In a second particularly preferred embodiment of the method according to the invention, the arrangement is also designed to measure a moment acting on the machine element and lying in the axis, ie a torsional moment, and a transverse force acting on the machine element perpendicular to the axis. The machine element has three of the magnetization areas with alternating polarities. The axially central one of the magnetization areas has the same axial position as two of the magnetic field sensors, these two magnetic field sensors having the same axial position being arranged opposite one another with respect to the axis. Two of the four magnetic field sensors each have the same tangential position and are axially adjacent. The axially outer magnetization areas each have the same axial position as one of the four magnetic field sensors. A first of the four magnetic field sensors has the same axial position as one of the magnetization areas arranged axially on the outside. The first magnetic field sensor outputs a measurement signal a ₁ . The magnetic field sensor axially adjacent to the first magnetic field sensor and having the same circumferential position as the first magnetic field sensor forms a second of the magnetic field sensors, which outputs a measurement signal b ₁ . The measurement signals a ₁ and b ₁ represent the axial directional components of the magnetic field occurring because of the inverse magnetostrictive effect with the same sense of direction; ie the measurement signals a ₁ and b ₁ represent the axial directional components with the same sign. The magnetic field sensor opposite the second magnetic field sensor with respect to the axis and having the same axial position as the second magnetic field sensor forms a third of the magnetic field sensors which outputs a measurement signal b ₂ . The measurement signals b ₁ and b ₂ represent the axial directional components of the magnetic field that occurs because of the inverse magnetostrictive effect and has an opposite sense of direction; ie the measurement signals b ₁ and b ₂ represent the axial directional components with different signs. The magnetic field sensor axially adjacent to the third magnetic field sensor and having the same circumferential position as the third magnetic field sensor forms a fourth of the magnetic field sensors, which outputs a measurement signal c ₂ . The measurement signals b ₂ and c ₂ represent the axial directional components of the magnetic field occurring because of the inverse magnetostrictive effect with the same sense of direction; ie the measurement signals b ₂ and c ₂ represent the axial directional components with the same sign. At least two of the measured values of the torsional moment are determined according to one of the following regulations: $${\mathrm{M.}}_1=\frac{a_1-c_2-b_1+b_1}{\mathrm{4th}}$$

$${\mathrm{M.}}_2=\frac{a_1-b_1}{2}$$

$${\mathrm{M.}}_3=\frac{b_2-c_2}{2}$$

The mathematical rules show that there are at least three of the combinations of magnetic field sensors that are sufficient to measure the torsional moment. The first combination includes the first, second, third, and fourth magnetic field sensors. The second combination includes the first and second magnetic field sensors. The third combination includes the third and fourth magnetic field sensors.

$$M_2^{\text{'}}=k_2\cdot M_2=k_2\cdot \frac{a_1-b_1}{2}$$

$$M_3^{\text{'}}=k_3\cdot M_3=k_3\cdot \frac{b_2-c_2}{2}$$

Before the arrangement was used as intended, the first correction factor k ₁ for the first combination of magnetic field sensors, the second correction factor k ₂ for the second combination of magnetic field sensors and the third correction factor k ₃ for the third combination of magnetic field sensors were determined. These correction factors are applied to the measured values by multiplication, whereby the first corrected measured value M ' ₁ , the second corrected measured value M' ₂ , and the third corrected measured value M ' ₃ are obtained: $${\mathrm{M.}}_1^{\text{'}}=k_1\cdot {\mathrm{M.}}_1=k_1\cdot \frac{a_1-c_2-b_1+b_2}{\mathrm{4th}}$$

$${\mathrm{M.}}_2^{\text{'}}=k_2\cdot {\mathrm{M.}}_2=k_2\cdot \frac{a_1-b_1}{2}$$

$${\mathrm{M.}}_3^{\text{'}}=k_3\cdot {\mathrm{M.}}_3=k_3\cdot \frac{b_2-c_2}{2}$$

$$T=\left|M_1^{\text{'}}-M_3^{\text{'}}\right|$$

$$T=\left|M_2^{\text{'}}-M_3^{\text{'}}\right|$$

$$T={\left(M_1^{\text{'}}-M_2^{\text{'}}\right)}^2$$

$$T={\left(M_1^{\text{'}}-M_3^{\text{'}}\right)}^2$$

$$T={\left(M_2^{\text{'}}-M_3^{\text{'}}\right)}^2$$

The test signal T is preferably determined according to one of the following rules: $$T=\left|{\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_2^{\text{'}}\right|$$

$$T=\left|{\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right|$$

$$T=\left|{\mathrm{M.}}_2^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right|$$

$$T={\left({\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_2^{\text{'}}\right)}^2$$

$$T={\left({\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right)}^2$$

$$T={\left({\mathrm{M.}}_2^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right)}^2$$

$$T={\left(M_1^{\text{'}}-M_2^{\text{'}}\right)}^2+{\left(M_1^{\text{'}}-M_3^{\text{'}}\right)}^2+{\left(M_2^{\text{'}}-M_3^{\text{'}}\right)}^2$$

Preferably, not just two, but all of the three corrected measured values M ' ₁ , M' ₂ , and M ' _{3 are} determined. The test signal T is preferably determined according to one of the following rules: $$T=\left|{\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_2^{\text{'}}\right|+\left|{\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right|+\left|{\mathrm{M.}}_2^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right|$$

$$T={\left({\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_2^{\text{'}}\right)}^2+{\left({\mathrm{M.}}_1^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right)}^2+{\left({\mathrm{M.}}_2^{\text{'}}-{\mathrm{M.}}_3^{\text{'}}\right)}^2$$

$$M_2=\frac{a_1-b_1}{2}$$

$$M_3=\frac{c_1-b_1}{2}$$

$$M_4=\frac{a_1-2\cdot b_1+c_1}{4}$$

$$M_5=\frac{a_2-b_2}{2}$$

$$M_6=\frac{c_2-b_2}{2}$$

$$M_7=\frac{a_2-2\cdot b_2+c_2}{4}$$

In a third particularly preferred embodiment of the method according to the invention, the arrangement is again designed to measure a moment acting on the machine element and lying in the axis, ie a torsional moment, and a transverse force acting on the machine element perpendicular to the axis. The machine element has three of the magnetization areas with alternating polarities. Each of the magnetization areas has the same axial position as two of the magnetic field sensors, these two magnetic field sensors having the same axial position being arranged opposite one another with respect to the axis. Three of the six magnetic field sensors each have the same tangential position and are axially adjacent. A first of the six magnetic field sensors has the same axial position as one of the magnetization areas arranged axially on the outside. The first magnetic field sensor outputs a measurement signal a ₁ . The magnetic field sensor opposite the first magnetic field sensor in relation to the axis and having the same axial position as the first magnetic field sensor forms a second of the magnetic field sensors which outputs a measurement signal a ₂ . The measurement signals a ₁ and a ₂ represent the axial directional components of the magnetic field occurring because of the inverse magnetostrictive effect with opposite sense of direction; ie the measurement signals a ₁ and a ₂ represent the axial directional components with different signs. The magnetic field sensor axially adjacent to the first magnetic field sensor and having the same circumferential position as the first magnetic field sensor forms a third of the magnetic field sensors, which outputs a measurement signal b ₁ . The third magnetic field sensor has the same axial position as the central magnetization area. The measurement signals a ₁ and b ₁ represent the axial directional components of the magnetic field occurring because of the inverse magnetostrictive effect with the same sense of direction; ie the measurement signals a ₁ and b ₁ represent the axial directional components with the same sign. The magnetic field sensor opposite the third magnetic field sensor in relation to the axis and having the same axial position as the third magnetic field sensor forms a fourth of the magnetic field sensors, which outputs a measurement signal b ₂ . The measurement signals b ₁ and b ₂ represent the axial directional components of the magnetic field that occurs because of the inverse magnetostrictive effect and has an opposite sense of direction; ie the measurement signals b ₁ and b ₂ represent the axial directional components with different signs. The magnetic field sensor axially adjacent to the third magnetic field sensor and having the same circumferential position as the first magnetic field sensor and the third magnetic field sensor forms a fifth of the magnetic field sensors which outputs a measurement signal c ₁ . The measurement signals b ₁ and c ₁ represent the axial directional components of the magnetic field occurring due to the inverse magnetostrictive effect with the same sense of direction; ie the measurement signals b ₁ and c ₁ represent the axial directional components with the same sign. The magnetic field sensor opposite the fifth magnetic field sensor in relation to the axis and having the same axial position as the fifth magnetic field sensor forms a sixth of the magnetic field sensors, which outputs a measurement signal c ₂ . The measurement signals c ₁ and c ₂ represent the axial directional components of the magnetic field that occurs due to the inverse magnetostrictive effect and has an opposite sense of direction; ie the measurement signals c ₁ and c ₂ represent the axial directional components with different signs. At least two of the measured values of the torsional moment are determined according to one of the following regulations: $${\mathrm{M.}}_1=\frac{a_1-2\cdot b_1+c_1-a_2+2\cdot b_2-c_2}{\mathrm{8th}}$$

$${\mathrm{M.}}_2=\frac{a_1-b_1}{2}$$

$${\mathrm{M.}}_3=\frac{c_1-b_1}{2}$$

$${\mathrm{M.}}_{\mathrm{4th}}=\frac{a_1-2\cdot b_1+c_1}{\mathrm{4th}}$$

$${\mathrm{M.}}_5=\frac{a_2-b_2}{2}$$

$${\mathrm{M.}}_6=\frac{c_2-b_2}{2}$$

$${\mathrm{M.}}_{\mathrm{7th}}=\frac{a_2-2\cdot b_2+c_2}{\mathrm{4th}}$$

The mathematical rules show that there are at least seven of the combinations of magnetic field sensors that are sufficient to measure the torsional moment. The first combination comprises the first, the second, the third, the fourth, the fifth and the sixth magnetic field sensor. The second combination includes the first and third magnetic field sensors. The third combination includes the third and fifth magnetic field sensors. The fourth combination includes the first, third and fifth magnetic field sensors. The fifth combination includes the second and fourth magnetic field sensors. The sixth combination includes the fourth and the sixth magnetic field sensor. The seventh combination includes the second, fourth and sixth magnetic field sensors.

Preferably, not just two, but at least four, or more preferably all of the seven measured values M ₁ to M _{7 are} determined. The correction factors and the corrected measured values are preferably determined in accordance with the first and second particularly preferred embodiment. The test signal T is preferably determined in accordance with the first and second particularly preferred embodiment.

$$M_2=\frac{a_1-b_{11}-b_{12}+c_1}{4}$$

$$M_3=\frac{a_2-b_{21}-b_{22}+c_2}{4}$$

In a fourth particularly preferred embodiment of the method according to the invention, the arrangement is again designed to measure a moment acting on the machine element and lying in the axis, ie a torsional moment, and a transverse force acting on the machine element perpendicular to the axis. The machine element has three of the magnetization areas with alternating polarities. The two axially outwardly arranged magnetization areas each have the same axial position as two of the magnetic field sensors, these two magnetic field sensors having the same axial position being arranged opposite one another with respect to the axis. The axially central magnetization area has the same axial position as four of the magnetic field sensors, two of these magnetic field sensors being arranged directly next to one another and forming a pair. Because of this immediately adjacent arrangement, the magnetic field sensors of each of the two pairs have essentially the same position. The two pairs having the same axial position are arranged opposite one another with respect to the axis. Four of the eight each Magnetic field sensors have the same tangential position and are axially adjacent. A first of the eight magnetic field sensors has the same axial position as one of the magnetization areas arranged axially on the outside. The first magnetic field sensor outputs a measurement signal a ₁ . The magnetic field sensor opposite the first magnetic field sensor in relation to the axis and having the same axial position as the first magnetic field sensor forms a second of the magnetic field sensors which outputs a measurement signal a ₂ . The measurement signals a ₁ and a ₂ represent the axial directional components of the magnetic field that occurs due to the inverse magnetostrictive effect and has an opposite sense of direction; ie the measurement signals a ₁ and a ₂ represent the axial directional components with different signs. That pair of magnetic field sensors which is axially adjacent to the first magnetic field sensor and has the same circumferential position as the first magnetic field sensor comprises a third of the magnetic field sensors, which outputs a measurement signal b ₁₁ , and a fourth of the magnetic field sensors, which outputs a measurement signal b ₁₂ . The third magnetic field sensor and the fourth magnetic field sensor have the same axial position as the axially central magnetization area. The measurement signals a ₁ , b ₁₁ and b ₁₂ represent the axial directional components of the magnetic field occurring due to the inverse magnetostrictive effect with the same sense of direction; ie the measurement signals a ₁ , b ₁₁ and b ₁₂ represent the axial directional components with the same sign. The measurement signals a ₂ , b ₂₁ and b ₂₂ represent the axial directional components of the magnetic field occurring because of the inverse magnetostrictive effect with the same sense of direction; ie the measurement signals a ₂ , b ₂₁ and b ₂₂ represent the axial directional components with the same sign. The pair opposite the third and fourth magnetic field sensors in relation to the axis and having the same axial position as the third and fourth magnetic field sensors comprises a fifth of the magnetic field sensors, which outputs a measurement signal b ₂₁ , and a sixth of the magnetic field sensors, which outputs a measurement signal b ₂₂ . The measurement signals b ₁₁ and b ₂₁ represent the axial directional components of the magnetic field that occurs because of the inverse magnetostrictive effect and has an opposite sense of direction; ie the measurement signals b ₁₁ and b ₂₁ represent the axial directional components with different signs. The measurement signals b ₂₁ and b ₂₂ represent the axial directional components of the magnetic field occurring because of the inverse magnetostrictive effect with the same sense of direction; ie the measurement signals b ₂₁ and b ₂₂ represent the axial directional components with the same sign. The magnetic field sensor axially adjacent to the third magnetic field sensor and having the same circumferential position as the first magnetic field sensor, the third magnetic field sensor and the fourth magnetic field sensor forms a seventh of the magnetic field sensors, which outputs a measurement signal c ₁ . The measurement signals b ₁₁ , b ₁₂ and c ₁ represent the axial directional components of the magnetic field occurring because of the inverse magnetostrictive effect with the same sense of direction; ie the measurement signals b ₁₁ , b ₁₂ and c ₁ represent the axial directional components with the same sign. The magnetic field sensor opposite the seventh magnetic field sensor in relation to the axis and having the same axial position as the seventh magnetic field sensor forms an eighth of the magnetic field sensors, which outputs a measurement signal c ₂ . The measurement signals c ₁ and c ₂ represent the axial direction components because of the inverse magnetostrictive effect occurring magnetic field with opposite sense of direction; ie the measurement signals c ₁ and c ₂ represent the axial directional components with different signs. The measurement signals b ₂₁ , b ₂₂ and c ₂ represent the axial directional components of the magnetic field occurring due to the inverse magnetostrictive effect with the same sense of direction; ie the measurement signals b ₂₁ , b ₂₂ and c ₂ represent the axial directional components with the same sign. At least two of the measured values of the torsional moment are determined according to one of the following regulations: $${\mathrm{M.}}_1=\frac{a_1-b_{11}-{\mathrm{<figure-callout\; id="12"\; label="b"\; filenames="DE102019120468A1\_0042.png,DE102019120468A1\_0043.png"\; state="\{\{state\}\}">b</figure-callout>}}_{12}+c_1-a_2+b_{\mathrm{21st}}+b_{\mathrm{22nd}}-c_2}{\mathrm{8th}}$$

$${\mathrm{M.}}_2=\frac{a_1-b_{11}-{\mathrm{<figure-callout\; id="12"\; label="b"\; filenames="DE102019120468A1\_0042.png,DE102019120468A1\_0043.png"\; state="\{\{state\}\}">b</figure-callout>}}_{12}+c_1}{\mathrm{4th}}$$

$${\mathrm{M.}}_3=\frac{a_2-b_{\mathrm{21st}}-b_{\mathrm{22nd}}+c_2}{\mathrm{4th}}$$

The mathematical rules show that there are at least three of the combinations of magnetic field sensors that are sufficient to measure the torsional moment. The first combination comprises the first, the second, the third, the fourth, the fifth, the sixth, the seventh and the eighth magnetic field sensor. The second combination includes the first, third, fourth and seventh magnetic field sensors. The third combination includes the second, fifth, sixth and eighth magnetic field sensors.

Preferably, not just two, but at least three of the measured values M ₁ to M _{3 are} determined. The correction factors and the corrected measured values are preferably determined in accordance with the first and second particularly preferred embodiment. The test signal T is preferably determined in accordance with the first and second particularly preferred embodiment.

The four particularly preferred embodiments described preferably also have features that are described above as preferred.

The arrangement according to the invention is used to measure a force and / or a moment on a machine element extending in an axis. The machine element has at least two magnetization regions extending circumferentially around the axis, each for one magnetization. The arrangement comprises at least four magnetic field sensors each for measuring an axial directional component of a magnetic field caused by the magnetization and by the force and / or the moment. There are at least two combinations of at least two of the magnetic field sensors. Any of these combinations is sufficient to measure force or moment. The arrangement also includes a measurement signal processing unit which is designed to carry out the method according to the invention. The measurement signal processing unit is preferably designed to carry out one of the described preferred embodiments of the method according to the invention. In addition, the arrangement preferably also has features that are specified in connection with the method according to the invention.

The measurement signal processing unit is preferably formed by a microcontroller. In the broader sense, the measurement signal processing unit is preferably formed by a computing unit.

• 1 eine erste bevorzugte Ausführungsform einer erfindungsgemäßen Anordnung in zwei Ansichten;
• 2 eine zweite bevorzugte Ausführungsform der erfindungsgemäßen Anordnung in zwei Ansichten;
• 3 eine dritte bevorzugte Ausführungsform der erfindungsgemäßen Anordnung in zwei Ansichten; und
• 4 eine vierte bevorzugte Ausführungsform der erfindungsgemäßen Anordnung in zwei Ansichten.

Further details, advantages and developments of the invention emerge from the following description of preferred embodiments of the invention with reference to the drawing. Show it:

• 1 a first preferred embodiment of an arrangement according to the invention in two views;
• 2 a second preferred embodiment of the arrangement according to the invention in two views;
• 3 a third preferred embodiment of the arrangement according to the invention in two views; and
• 4th a fourth preferred embodiment of the arrangement according to the invention in two views.

1 shows a first preferred embodiment of an arrangement according to the invention in a cross-sectional view and in a longitudinal sectional view. The arrangement comprises a machine element made of steel in the form of a hollow flange 01 which is in an axis 03 extends. On the hollow flange 01 acts a torsional moment Mt, which can be measured with the arrangement according to the invention.

The hollow flange 01 has two magnetization areas 04 in the form of circumferential tracks. The two magnetization areas 04 are permanently magnetized and polarized in opposite directions, as indicated by an arrow showing the direction of rotation 05 is shown. The two magnetization areas 04 form a primary sensor for measuring the torsional moment Mt using the inverse magnetostrictive effect.

The arrangement also includes four magnetic field sensors 06 located inside the hollow flange 01 are located. The four magnetic field sensors 06 are equidistant from the axis 03 on.

The four magnetic field sensors 06 each serve to measure an axial directional component of the magnetization of the magnetization areas 04 and by the torsional moment Mt due to the inverse magnetostrictive effect occurring magnetic field. A magnetic field direction of this magnetic field is in each case at the positions of the magnetic field sensors 06 by an arrow illustrating the respective magnetic field direction 07 shown. A positive measuring direction of the magnetic field sensors 06 is through that for the magnetic field sensors 06 used symbol illustrated with an arrow drawn.

Two of the four magnetic field sensors 06 have the same axial position as a first of the magnetization areas 04 on. Two more of the four magnetic field sensors 06 have the same axial position as a second of the magnetization areas 04 on.

A first magnetic field sensor 11 of the four magnetic field sensors 06 outputs a signal a ₁ . The first magnetic field sensor 11 in relation to the axis 03 opposing magnetic field sensor 06 forms a second magnetic field sensor 12 , which outputs a signal a ₂ . The one for the first magnetic field sensor 11 axially adjacent magnetic field sensor 06 forms a third magnetic field sensor 13 , which outputs a signal b ₁ . The third magnetic field sensor 13 in relation to the axis 03 opposing magnetic field sensor 06 forms a fourth magnetic field sensor 14th , which outputs a signal b ₂ .

The arrangement further comprises a microcontroller (not shown) which is used for measuring signal processing and is configured to carry out a method according to the invention for checking the arrangement.

2 shows a second preferred embodiment of the arrangement according to the invention in a cross-sectional view and in a longitudinal sectional view. This embodiment is initially similar to that in 1 embodiment shown. In contrast to the in 1 The first embodiment shown has the hollow flange 01 three of the magnetization areas 04 that are alternately polarized. The first magnetic field sensor 11 of the four magnetic field sensors 06 in turn outputs the signal a ₁ . The second magnetic field sensor 12 is to the first magnetic field sensor 11 axially adjacent and outputs the signal b ₁ . The third magnetic field sensor 13 is in relation to the axis 03 the first magnetic field sensor 11 arranged opposite and outputs the signal b ₂ . The fourth magnetic field sensor 14th is to the third magnetic field sensor 13 axially adjacent and outputs the signal c ₂ .

3 shows a third preferred embodiment of the arrangement according to the invention in a cross-sectional view and in a longitudinal sectional view. This embodiment is initially similar to that in 2 embodiment shown. In contrast to the in 2 The second embodiment shown comprises six of the magnetic field sensors 06 . The first magnetic field sensor 11 of the six magnetic field sensors 06 in turn outputs the signal a ₁ . The second magnetic field sensor 12 is in relation to the axis 03 the first magnetic field sensor 11 arranged opposite and outputs the signal a ₂ . The third magnetic field sensor 13 is to the first magnetic field sensor 11 axially adjacent and outputs the signal b ₁ . The fourth magnetic field sensor 14th is in relation to the axis 03 the third magnetic field sensor 13 arranged opposite and outputs the signal b ₂ . A fifth magnetic field sensor 15th of the six magnetic field sensors 06 is to the third magnetic field sensor 13 axially adjacent and outputs the signal c ₁ . A sixth magnetic field sensor 16 of the six magnetic field sensors 06 is in relation to the axis 03 the fifth magnetic field sensor 15th arranged opposite and outputs the signal c ₂ .

4th shows a fourth preferred embodiment of the arrangement according to the invention in a cross-sectional view and in a longitudinal sectional view. This embodiment is initially similar to that in 3 embodiment shown. In contrast to the in 3 The third embodiment shown comprises eight of the magnetic field sensors 06 . The first magnetic field sensor 11 of the six magnetic field sensors 06 in turn outputs the signal a ₁ . The second magnetic field sensor 12 is in relation to the axis 03 the first magnetic field sensor 11 arranged opposite and outputs the signal a ₂ . The third magnetic field sensor 13 is to the first magnetic field sensor 11 axially adjacent and outputs the signal b ₁₁ . The fourth magnetic field sensor 14th is located directly next to the third magnetic field sensor 13 outputs the signal b ₁₂ . The fifth magnetic field sensor 15th is in relation to the axis 03 the third magnetic field sensor 13 arranged opposite and outputs the signal b ₂₁ . The sixth magnetic field sensor 16 is located directly next to the fifth magnetic field sensor 13 outputs the signal b ₂₂ . A seventh magnetic field sensor 17th of the eight magnetic field sensors 06 is to the third magnetic field sensor 13 axially adjacent and outputs the signal c ₁ . An eighth magnetic field sensor 18th of the six magnetic field sensors 06 is in relation to the axis 03 the seventh magnetic field sensor 17th arranged opposite and outputs the signal c ₂ .

List of reference symbols

01

Machine element in the form of a hollow flange

02

-

03

axis

04

Magnetization range

05

Orbital sense

06

Magnetic field sensor

07

Magnetic field direction

08

-

09

-

10

-

11

first magnetic field sensor

12

second magnetic field sensor

13

third magnetic field sensor

14th

fourth magnetic field sensor

15th

fifth magnetic field sensor

16

sixth magnetic field sensor

17th

seventh magnetic field sensor

18th

eighth magnetic field sensor

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• US 6490934 B2 [0002]
• EP 0803053 B1 [0003]
• US 8893562 B2 [0004]
• US 8578794 B2 [0005]
• US 2014/0360285 A1 [0006, 0009]
• US 8087304 B2 [0007]
• US 2004/0154412 A1 [0008]
• US 9151686 B2 [0010]
• DE 102015209286 A1 [0011]

Claims (10)

Method for testing an arrangement for measuring a force and / or a moment (Mt) on a machine element (01) extending in an axis (03), the machine element (01) at least two extending circumferentially around the axis (03) Has magnetization areas (04) for one magnetization each, the arrangement comprising at least four magnetic field sensors (06) for measuring an axial component of a magnetic field caused by the magnetization and by the force and / or by the moment (Mt), with at least two combinations of at least two of the magnetic field sensors (06), each of the combinations being sufficient to measure the force or the moment (Mt), and the method comprising the following steps: - Determining a first correction factor for calibrating a first one of the combinations of the magnetic field sensors (06); - Determining a second correction factor for calibrating a second one of the combinations of the magnetic field sensors (06); - Determining a first measured value of the force or the moment (Mt) with the first combination of the magnetic field sensors (06); Applying the first correction factor to the first measured value in order to obtain a first corrected measured value; - Determining a second measured value of the force or the moment (Mt) with the second combination of the magnetic field sensors (06); Applying the second correction factor to the second measured value in order to obtain a second corrected measured value; and - Comparing the first corrected measured value with the second corrected measured value. Procedure according to Claim 1 , characterized in that it comprises the following further steps: - determining a third correction factor for calibrating a third of the combinations of the magnetic field sensors (06); - Determining a third measured value of the force or the moment (Mt) with the third combination of the magnetic field sensors (06); Applying the third correction factor to the third measured value in order to obtain a third corrected measured value; and comparing the first corrected measured value, the second corrected measured value and the third corrected measured value. Procedure according to Claim 1 or 2 , characterized in that, in order to compare the corrected measured values, absolute amounts of differences between the corrected measured values or squares of differences between the corrected measured values are formed. Procedure according to Claim 3 , characterized in that it comprises a further step in which a sum of the absolute amounts of the differences between the corrected measured values or a sum of the squares of the differences between the corrected measured values is formed. Procedure according to Claim 4 , characterized in that an error signal is output if the sum of the absolute amounts or the sum of the squares of the differences exceeds a previously defined maximum. Method according to one of the Claims 1 to 5 , characterized in that the magnetic field sensors (06) each have the same tangential position as at least one other of the magnetic field sensors (06). Method according to one of the Claims 1 to 6 , characterized in that the magnetic field sensors (06) each have an axial position of one of the magnetization areas (04). Procedure according to Claim 7 , characterized in that at least one of the magnetization areas (04) has the same axial position as two of the magnetic field sensors (06), these two magnetic field sensors (06) being arranged opposite one another with respect to the axis (03). Procedure according to Claim 8 , characterized in that each of the magnetization areas (04) has the same axial position as two of the magnetic field sensors (06) arranged opposite one another with respect to the axis (03), and that two of the magnetic field sensors (06) each have the same tangential position and axially are adjacent, a first of the magnetic field sensors (06, 11) outputting a measurement signal a ₁ , the magnetic field sensor (06, 12) opposite the first magnetic field sensor (11) in relation to the axis (03) a second of the magnetic field sensors (06, 12) ), which outputs a measurement signal a ₂ , the measurement signals a ₁ and a _{2 representing} the axial directional components of the magnetic field occurring with opposite sense of direction, the magnetic field sensor (06, 13) axially adjacent to the first magnetic field sensor (11) being a third of the magnetic field sensors (06, 13), which outputs a measurement signal b ₁ , the measurement signals a ₁ and b _{1 being} the axial directional component The magnetic field sensor (06, 14) opposite the third magnetic field sensor (13) in relation to the axis (03) forms a fourth of the magnetic field sensors (06, 14), which generates a measurement signal b ₂ outputs, wherein the measurement signals b ₁ and b _{2 represent} the axial directional components of the occurring magnetic field with opposite sense of direction, and the at least two measured values are each determined according to one of the following rules: $${\mathrm{M.}}_1=\frac{a_1-a_2-b_1+b_2}{\mathrm{4th}}$$

$${\mathrm{M.}}_2=\frac{a_1-b_1}{2}$$

$${\mathrm{M.}}_3=\frac{b_2-a_2}{2}$$

Arrangement for measuring a force and / or a moment (Mt) on a machine element (01) extending in an axis (03), the machine element (01) at least two magnetization areas (04) extending circumferentially around the axis (03) for one magnetization each, the arrangement comprising at least four magnetic field sensors (06) for measuring an axial directional component of a magnetic field caused by the magnetization and by the force and / or by the moment (Mt), with at least two combinations of at least two each of the magnetic field sensors (06), each of the combinations being sufficient for measuring the force or the moment (Mt), and wherein the arrangement further comprises a measurement signal processing unit which is used to carry out a method according to one of the Claims 1 to 9 is trained.

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