Measuring device and method for determining an angular position signal

Abstract

A measuring device (1) has a magnet device (2) and a sensor device (3) that are rotatable relative to each other about a rotational axis (4). For generating magnetic field measurement signals, the sensor device (3) has a number of at least three magnetic field sensors (5, 6, 7) arranged at angular offsets relative to each other, each with an output (8, 9, 10) for outputting a magnetic field measurement signal. The outputs (8, 9, 10) are connected to a first signal path (15) in which a transformation device (17) is arranged for transforming the magnetic field measurement signals into a plurality of phase-shifted transformation signals, the number of which is smaller than the number of magnetic field sensors (5, 6, 7). Output terminals (13, 14) for the transformation signals are connected to an evaluation device (18) for generating the angular position signal.In a further signal path, a comparator (21) is arranged, which is connected to the measurement signal output (8, 9, 10) of one of the magnetic field sensors (5, 6, 7) for comparing the magnetic field measurement signal with a comparator threshold signal. The evaluation unit (18) has a phase position comparator (24, 24') for detecting a phase error, which has a first phase position comparator input (25) connected to an output terminal of the transformation unit (12) and a second phase position comparator input (26) connected to the comparator output (23).

Description

[0001] The invention relates to a measuring device for determining an angular position signal, comprising a magnetic device and a sensor device which are mounted relative to one another for rotation about a geometric axis of rotation, wherein the sensor device has a number of at least three magnetic field sensors arranged at an offset angle relative to one another with respect to the axis of rotation for generating mutually phase-shifted magnetic field measurement signals, wherein the magnetic field sensors have measurement signal outputs for outputting the magnetic field measurement signals, wherein the sensor device has a first signal path in which a transformation device is arranged for transforming the at least three magnetic field measurement signals into a plurality of phase-shifted transformation signals which is smaller than the number of magnetic field sensors,The measurement signal outputs of each magnetic field sensor are each connected to an input of the transformation device, and the transformation device has an output connection for each transformation signal, and the output connections are connected to an evaluation device, by means of which the angular position signal can be generated as a function of the transformation signals and output at an angular position signal output. Furthermore, the invention relates to a method for determining an angular position signal, comprising a magnetic device and a sensor device, in which the magnetic device and the sensor device are mounted so as to be rotatable relative to one another about a rotation axis, the sensor device comprising a number of at least three magnetic field sensors arranged at an offset angle relative to one another with respect to the rotation axis for generating mutually phase-shifted magnetic field measurement signals.wherein the magnetic field measurement signals are transformed into a plurality of phase-shifted transformation signals which is smaller than the number of magnetic field sensors, and wherein the angular position signal is generated with the aid of the phase-shift signals thus obtained.

[0002] DE 10 2014 109 693 A1 discloses a device and a measuring method of the type mentioned above. The measuring method provides a magnetic device and a sensor device that are mounted so as to be rotatable relative to each other about a geometric axis of rotation. The sensor device has three magnetic field sensors that are offset relative to each other in terms of rotation angle with respect to the axis of rotation such that the magnetic field sensors detect magnetic field measurement signals that are 120 degrees out of phase with each other.

[0003] Two mutually orthogonal output signals are calculated from the three output signals of the magnetic field sensors using a transformation. In the case of a continuously rotating magnetic device, the output signals result in two harmonic oscillations (sin, cos), which are phase-shifted by 90 degrees. From these two signals, or rather from their instantaneous values, the angular position is then directly calculated in a suitable evaluation device using the arctangent function. The device and method are not limited to three magnetic field sensors and primarily serve to compensate for external magnetic interference fields, which occur particularly in automotive electronics applications. This enables more precise measurement of angular positions. The precision of the angular position signal is increased by using more than three magnetic field sensors.

[0004] Many sensor devices also have the option of outputting signals in differential form, for which phase-switching devices (phase shift by 180°) are used. There are also circuits that swap sin and cos signals, thus resulting in a jump of n*90° or a change in direction. Such electronic circuits that influence the phase position of the two output signals exist and can malfunction due to the external interference fields described above or due to other sources. The external interference fields occur either as homogeneous or gradient, static magnetic fields or in the form of transient or periodic alternating fields. The latter can potentially lead to malfunctions in the electronic circuits, while the former are more likely to distort the sensor or reference magnetic field provided by the magnetic device.The robustness of such arrangements and the associated phenomena are generally summarized under the umbrella term of electromagnetic compatibility (EMC). The formation of the arctangent function from the two orthogonal output signals (sin, cos) then leads to an incorrect result for the angular position, even though the EMC-related interference directly introduced into the useful and measured signals (distortion of the sensor's magnetic field) has already been compensated for by the state-of-the-art method.

[0005] US 2011 / 0 043 197 A1 further discloses a measuring device and a method for determining an angular position signal, comprising a magnetic device and a sensor device mounted relative to one another for rotation about a geometric axis of rotation. The sensor device comprises at least three magnetic field sensors arranged at an offset angle relative to one another with respect to the axis of rotation for generating phase-shifted magnetic field measurement signals. An approximately sinusoidal first signal for representing the orientation of the magnetic device is derived from magnetic field measurement signals of a first combination of the magnetic field sensors, such that a 360° rotation of the magnetic device results in a sine wave.In addition, a second signal, phase-shifted by 90° relative to the first signal, is derived from magnetic field measurement signals from a second combination of magnetic field sensors to represent the orientation of the magnetic device. Both combinations allow the angular position to be calculated using an arctangent function. Depending on the results obtained, the magnetic field sensors are recombined in a further step to obtain a more accurate angular position signal.

[0006] DE 10 2017 106 655 A1 further discloses a measuring device and a method for determining an angular position signal, comprising a magnetic device and a sensor device mounted relative to each other for rotation about a geometric axis of rotation. The sensor device has at least two magnetic field sensors arranged axially and / or radially offset from each other, so that the influence of an interference field can be compensated for by forming a gradient in the magnetic field measurement signals.

[0007] The task therefore lies in detecting any incorrect influence on the phase position in order to promptly identify any incorrect calculation of the angular position. Conversely, correct manipulation of the phase position, which is required, for example, by zero-point calibration, increases the confidence level of the calculated angular position. In safety-related applications, such as those found in many areas of automotive engineering, this task is essential.

[0008] This object is achieved with regard to the measuring device of the type mentioned at the outset in that the sensor device has at least one further signal path in which a comparator is arranged, which is connected to the measurement signal output of at least one magnetic field sensor for comparing the magnetic field measurement signal of one of the magnetic field sensors or a combination of the magnetic field measurement signals of several magnetic field sensors with a comparator threshold signal and has a comparator output for outputting a digital comparison value signal, that the evaluation device for detecting a phase error has a phase position comparison element with a first and a second phase position comparison element input, that the first phase position comparison element input is connected to the first output terminal of the transformation device or the angular position signal output and the second phase position comparison element input is connected to the comparator output,and that the phase position comparator has a phase position comparator output for outputting a phase position difference signal.,

[0009] The comparator threshold signal can be a non-differential or a differential comparator threshold signal. At a voltage value of the output signal of the connected magnetic field sensor determined by the comparator threshold signal, the digital comparator output switches to either the digital HIGH (logical "1") or LOW (logical "0") level when the comparator threshold signal is exceeded or undershot. The digital comparison value signal generated in this way corresponds to a digital phase position signal. In the case of a continuously rotating relative movement between the magnet and the sensor device, this is a digital output signal that is periodic, and whose period duration or frequency represents the phase position of the output signal of the magnetic field sensor relative to absolute time.If the magnetic device rotates at a constant speed relative to the sensor device, the digital comparison value signal is a periodic signal with a constant frequency. If the angular speed changes, the signal remains periodic, but the frequency varies according to the angular speed. The magnetic device can be permanently connected to the rotor of a drive whose angular position is to be measured. To simplify the evaluation of the transformation signals, they are preferably arranged orthogonally to each other.

[0010] With regard to the method, the above-mentioned object is achieved in that the magnetic field measurement signal of at least one magnetic field sensor or a combination of the magnetic field measurement signals of several magnetic field sensors is compared with a threshold value signal to generate a digital comparison value signal, and in that the phase position of at least one transformation signal or the phase position of the angular position signal is compared with the phase position of the digital comparison value signal to detect a phase error.

[0011] In an advantageous embodiment of the invention, the output terminals of the transformation device are indirectly connected to the evaluation device via a phase shift device. The phase shift device has a phase shifter output for each transformation signal for outputting a phase-shifted transformation signal shifted by a predetermined phase angle relative to the respective transformation signal. The phase shifter outputs are connected to the evaluation device for generating the angular position signal. The phase shift device enables a simple zero-point calibration of the angular position signal when the measuring device is in use, provided the individual transformation signals are each shifted by the same phase angle.This is particularly advantageous for measuring devices in which the sensor device is implemented from purely analog electronic circuit blocks. However, it is also possible to shift the first and second transformation signals by different phase angles using the phase shift device in order to compensate for errors in the phase position of the transformation signals relative to one another and, in particular, in the orthogonality of the transformation signals. Should a disturbance occur during the phase shift of the transformation signals that affects the phase position, this can be determined by comparing the angular position signal with the edges of the digital comparison value signal or by comparing at least one of the transformation signals, possibly phase-shifted using the phase shift device, with the edges of the digital comparison value signal.

[0012] In a preferred embodiment of the invention, the evaluation device for detecting a change in the phase position difference signal has a phase position difference signal monitoring device connected to the phase position comparator output. If a disturbance occurs in the first signal path, the first and / or second phase position difference signal changes, which is monitored by the phase position difference signal monitoring device. This enables a plausibility check of the first signal path, and errors in the signal processing that affect the phase position of the output signals (e.g., sin, cos) can be detected. If a phase error is detected, it can be displayed if necessary.

[0013] It is advantageous if the phase difference signal monitoring device has a comparison device for comparing the change in the phase difference signal with a tolerance band. The tolerance band is preferably selected such that small deviations that neither cause a malfunction nor impair safety during operation of the measuring device are not detected as errors by the comparison device.

[0014] In a typical design of the sensor device, the magnetic field sensors can be designed as Hall, TMR, GMR or AMR sensors.

[0015] In a suitable embodiment of the invention, the magnetic field sensors and the signal paths are implemented monolithically or hybridly integrated in a single encapsulated IC package.

[0016] In an alternative embodiment, the magnetic field sensors and the signal paths are implemented discretely on a carrier.

[0017] According to a further development, the measuring device has at least one modulation device which has a first input connected directly or indirectly via the phase shift device to one of the output terminals of the transformation device and a second input connected to the comparator output of the further signal path, as well as a modulation signal output, wherein the modulation signal output is connected to a demodulation device of the evaluation device assigned to the modulation device. An advantage of this further development is that the comparator signal present at the comparator output is transmitted for evaluation, e.g. as a DC component, together with the output signal of the transformation device or the phase shift device, and the evaluation or detection of a phase error can take place in an evaluation device separate from the measuring device.

[0018] Alternatively, the measuring device can have at least one operating current modulation device for the sensor device, to whose input the comparator output of the further signal path is connected, wherein the evaluation device is connected to an operating current demodulation device of the evaluation device assigned to the operating current modulation device. The advantage of this variant is that the digital comparison value signal can be transmitted to the evaluation device by modulating the operating current in order to perform the evaluation or detection of a phase error there.

[0019] It should be noted that all signals of the sensor device can be realized both as differential and as absolute value signals with a fixed reference potential.

[0020] In the following, embodiments of the invention are explained in more detail with reference to the drawing.

[0021] They show: Fig. 1 A schematic overview of a measuring device, Fig. 2 a block diagram of a first embodiment of the measuring device, Fig. 3 a block diagram of a second embodiment of the measuring device, Fig. 4 a block diagram of a third embodiment of the measuring device, Fig. 5 is a block diagram of a fourth embodiment of the measuring device, Fig. 6 a graphical representation of the two partial signals of a differential transformation signal, with the time t being plotted on the abscissa and the electrical voltage U being plotted on the ordinate, Fig. 7 is a graphical representation of a digital comparison value signal, with the time t being plotted on the abscissa and the electrical voltage U being plotted on the ordinate, Fig. 8 a graphical representation of the two partial signals of a modulated differential transformation signal, with the time t being plotted on the abscissa and the electrical voltage U being plotted on the ordinate, and Fig. 9 a block diagram of a fifth embodiment of the measuring device.

[0022] One in Fig. 1 The measuring device 1, designated as a whole by 1, for determining an angular position signal comprises a magnetic device 2 and a sensor device 3, which are mounted relative to one another by means of a bearing not shown in detail in the drawing, rotatable about an imaginary rotation axis 4. The magnetic device 2 has a north pole N and a south pole S, which are offset by 180° relative to the rotation axis 4. However, other embodiments are also conceivable in which the north and south poles are offset by angles other than 180°, in particular by unequal angles.

[0023] The sensor device 3 comprises three magnetic field sensors 5, 6, 7 arranged on a semiconductor chip, which are arranged at an angular distance of 120° relative to the rotation axis 4, offset in rotational angle. However, other configurations are also possible in which the magnetic field sensors 5, 6, 7 are arranged at different angular distances relative to each other, offset in rotational angle. This allows harmonics in the angular position signal to be reduced.

[0024] The semiconductor chip is arranged with its plane of extension orthogonal to the rotation axis 4. The magnetic field sensors 5, 6, 7 are preferably located on a circular path concentric with the rotation axis 4. When the magnetic device 2 is rotated about the rotation axis 4 relative to the sensor device 3, the magnetic field sensors 5, 6, 7 generate magnetic field measurement signals that are phase-shifted relative to one another. To output its magnetic field measurement signal, each magnetic field sensor 5, 6, 7 has a measurement signal output 8, 9, 10.

[0025] As in Fig. As can be seen in Figure 2, the sensor device 3 has a first signal path 11 in which a transformation device 12 is arranged for transforming the three magnetic field measurement signals into two mutually orthogonal transformation signals. The transformation device 12 has a first input connected to the measurement signal output 8 of a first magnetic field sensor 5, a second input connected to the measurement signal output 9 of a second magnetic field sensor 6, and a third input connected to the measurement signal output 10 of a third magnetic field sensor 7. The transformation device 12 is designed to perform a Clarke transformation, which transforms the magnetic field measurement signals into a sinusoidal first transformation signal (real part) and a cosinusoidal second transformation signal (imaginary part). The first transformation signal can be output at a first output terminal 13, and the second transformation signal can be output at a second output terminal 14.

[0026] The first output terminal 13 is connected to a first input of an evaluation device 18, and the second output terminal 14 is connected to a second input of the evaluation device 18. With the aid of the evaluation device 18, an angular position signal can be generated as a function of the first transformation signal present at the first output terminal 13 and the second transformation signal present at the second output terminal 14. This angular position signal indicates the rotational position in which the magnetic device 2 is rotationally positioned about the rotation axis 4 relative to the sensor device 3. The angular position signal is determined in a computing device 42 of the evaluation device 18 by calculating the arctangent of the quotient of the first transformation signal and the second transformation signal. The angular position signal can be output at an angular position signal output 19 of the evaluation device 18.

[0027] In the Fig. In the exemplary embodiment illustrated in Figure 3, a phase shift device 15 is also arranged in the first signal path 11, which has a first phase shifter input and a second phase shifter input. The first phase shifter input is connected to the first output terminal 13 of the transformation device 12, and the second phase shifter input is connected to the second output terminal 14 of the transformation device 12. This allows the zero point of the phase position to be calibrated. The first transformation signal, which is phase-shifted by the predetermined phase angle and is also referred to below as the first phase-shifted transformation signal, can be output at a first phase shifter output 16, and the second phase-shifted transformation signal, which is phase-shifted by the predetermined phase angle and is also referred to below as the second phase-shifted transformation signal, can be output at a second phase shifter output 17.

[0028] The first phase shifter output 16 is connected to the first input of an evaluation device 18, and the second phase shifter output 17 is connected to the second input of the evaluation device 18. With the aid of the evaluation device 18, an angular position signal can be generated as a function of the phase-shifted transformation signals present at the first and second phase shifter outputs 16, 17. This angular position signal indicates the rotational position in which the magnetic device 2 is rotationally positioned about the rotation axis 4 relative to the sensor device 3. The angular position signal is determined in a computing device 42 of the evaluation device 18 by calculating the arctangent of the quotient of the first phase-shifted transformation signal present at the first phase shifter output 16 and the second phase-shifted transformation signal present at the second phase shifter output 17.The angular position signal can be output at an angular position signal output 19 of the evaluation device 18.

[0029] In the Fig. 2 and Fig. In the embodiments illustrated in Figure 3, the sensor device 3 also has a further signal path 20 in which a comparator 21 is arranged, which has a first comparator input connected to the measurement signal output 8 of the first magnetic field sensor 5. A second comparator input, not shown in detail in the drawing, is connected to a threshold value transmitter for comparing the magnetic field measurement signal of the first magnetic field sensor 5 with a comparator threshold value signal. To output a digital comparison value signal 22, the comparator 21 has a comparator output 23 connected to a third input of the evaluation device 18. In a magnetic field sensor 5 with a non-differential measurement signal output 8, the comparator threshold value signal of the threshold value transmitter can, for example, be at a potential that corresponds to the middle of the supply voltage.In a magnetic field sensor 5 with a differential measurement signal output 8, the comparator threshold signal can correspond to the polarity of the measurement signal output 8. The edges of the digital comparison value signal 22 can coincide with the zero crossings of the magnetic field measurement signal present at the measurement signal output of the first magnetic field sensor 5.

[0030] To detect a phase error, the evaluation device 18 has a phase position comparison element 24. In the embodiment according to Fig. 3, the phase position comparator 24 has a first phase position comparator input 25 connected to the angular position signal output 19, a second phase position comparator input 26 connected to the comparator output 23 and a phase position comparator output 27 for outputting a phase position difference signal Δφ.

[0031] As in Fig. 4, the first phase position comparator input 25 of the phase position comparator 24' can also be connected to a phase shifter output 16 instead of to the angular position signal output 19. In the Fig. 2, the first phase position comparator input 25 could also be connected to one of the output terminals 13, 14 of the transformation device instead of to the angular position signal output 19.

[0032] To detect a change in the phase position difference signal Δφ, the evaluation device 18 has a phase position difference signal monitoring device 28, the input of which is connected to the phase position comparison element output 27 of the phase position comparison element 24. A signal indicating the change in the phase position difference signal Δφ can be output at an output of the phase position difference signal monitoring device 28. This output is connected to a comparison device 29, by means of which the change in the phase position difference signal Δφ can be compared with a predetermined tolerance band. The result of the comparison can be output in the form of a digital error signal at an output 30 of the comparison device 29.

[0033] In the Fig. In the embodiment shown in Figure 5, the measuring device 1 has two essentially identical modulation devices 31 and 32, each with two inputs. A first input of a first modulation device 31 is connected to the first phase shifter output 16, and a second input of the first modulation device 31 is connected to the comparator output 23. The first modulation device 31 has a first differential modulation signal output 33, which is connected to a first differential modulation signal input 34 of a first demodulation device (not shown in detail in the drawing) of the evaluation device 18.

[0034] A first input of a second modulation device 32 is connected to the second phase shifter output 17, and a second input of the second modulation device 32 is connected to the comparator output 23. The second modulation device 32 has a second differential modulation signal output 35, which is connected to a second differential modulation signal input 36 of a second demodulation device of the evaluation device 18 (not shown in detail in the drawing).

[0035] In the demodulation devices, the phase-shifted first and second transformation signals as well as the digital comparison value signal 22 are reconstructed from the modulated signals. A first phase difference value is then determined for the phase difference between the phase position of the angular position signal present at the angular position signal output 19 and the phase position of the digital comparison value signal 22 and compared with a tolerance range in order to check whether the angular position signal correlates with the digital comparison value signal 22. An erroneous influence on the phase position can be caused, for example, by EMC interference acting on the transformation device 12 and / or the phase shift device 15 and / or by random and / or systematic errors, e.g., in an integrated circuit of the sensor device 3. If one of the transformation signals ( Fig. 2) or one of the phase-shifted transformation signals ( Fig. 3) If the phase position is incorrectly influenced, an error signal is generated and output at the output 30 of the evaluation device 18.

[0036] As in Fig. 6 to 8, the digital comparison value signal 22 ( Fig. 7) as a DC component to each of the two differential partial signals 37, 38 ( Fig. 6) the first phase-shifted transformation signal, which is phase-shifted by the predetermined phase angle relative to the first transformation signal, is modulated. As in Fig. 6, the partial signal 38 corresponds to the inverted partial signal 37. The first phase-shifted transformation signal corresponds to the difference between the partial signals 37, 38. The modulated first partial signal 39 and the modulated second partial signal 40 are in Fig. 8. These signals are output at the first modulation signal output 33. The sum of the modulated partial signals 39, 40 corresponds to the digital comparison value signal 22.

[0037] In a corresponding manner, the digital comparison value signal 22 is modulated as a DC component onto each of the two differential partial signals of the second phase-shifted transformation signal by means of the second modulation device 32. The modulated first and second partial signals thus obtained are output at the second modulation signal output 35.

[0038] The evaluation device 18 calculates the angular position signal from the arctangent of the two phase-shifted transformation signals and performs phase error detection using the modulated partial signals 39, 40. The basis for this is the formation of the phase position difference signal Δφ, which represents the phase relationship between the output signal of the first signal path 11 and the output signal of the further signal path 20. The jumps or discontinuities 41 contained in the modulated partial signals 39, 40 can be detected in the evaluation device using conventional means, such as low-pass filtering.

[0039] In Fig. 9 shows a further embodiment of the measuring device 1, in which the operating current required for the operation of the sensor device 3 is drawn from the evaluation device 18 and passed from there to the sensor device 3 via an operating current modulation device 43. The operating current modulation device 43 has a control input which is connected to the comparator output 23 of the further signal path 20 for modulating the digital comparison value signal 22 onto the operating current of the sensor device 3. The evaluation device 18 has an operating current demodulation device (not shown in detail in the drawing) assigned to the operating current modulation device 42, by means of which the evaluation device 18 is able to demodulate the digital comparison value signal 22 from the modulated operating current in order to carry out error detection by forming and evaluating a phase difference.In this embodiment, the phase shifter outputs 16, 17 of the first signal path 15 are directly connected to the evaluation device 18.

[0040] It should be noted that for the implementation of the phase error detection method, a modulation of the digital comparison value signal 22 onto already existing signals and lines is not absolutely necessary. Rather, it is a practical extension of the invention, which at the level of the sensor device 3 may save additional lines / connections and correspondingly designed connections. This is the case, for example, if within the sensor device 3, the signal paths 11, 20 and the evaluation device 18 are spatially separated, but connected by a cable harness. Conversely, in the case of a complete monolithic integration, including also the evaluation device 18, a direct connection according to Fig. 2 or Fig. 3 more advantageous.

Claims

[1] Measuring device (1) for determining an angular position signal, comprising a magnetic device (2) and a sensor device (3) which are mounted so as to be rotatable relative to one another about a geometric axis of rotation (4), wherein the sensor device (3) has a number of at least three magnetic field sensors (5, 6, 7) arranged at an angle of rotation relative to one another with respect to the axis of rotation (4) for generating magnetic field measurement signals which are phase-shifted relative to one another, wherein the magnetic field sensors (5, 6, 7) have measurement signal outputs (8, 9, 10) for outputting the magnetic field measurement signals, wherein the sensor device (3) has a first signal path (11) in which a transformation device (12) is arranged for transforming the at least three magnetic field measurement signals into a plurality of phase-shifted transformation signals which is smaller than the number of magnetic field sensors (5, 6, 7), wherein the measurement signal outputs (8, 9, 10) each magnetic field sensor (5, 6,7) are each connected to an input of the transformation device (12) and the transformation device (12) has an output terminal (13, 14) for each transformation signal, and wherein the output terminals (13, 14) are connected to an evaluation device (18) by means of which the angular position signal can be generated as a function of the transformation signals and output at an angular position signal output (19), , characterized bythat the sensor device (3) has at least one further signal path (20) in which a comparator (21) is arranged, which is connected to the measurement signal output (8, 9, 10) of at least one magnetic field sensor (5, 6, 7) for comparing the magnetic field measurement signal of one of the magnetic field sensors (5, 6, 7) or a combination of the magnetic field measurement signals of several magnetic field sensors (5, 6, 7) with a comparator threshold signal and has a comparator output (23) for outputting a digital comparison value signal (22), that the evaluation device (18) for detecting a phase error has a phase position comparison element (24, 24') with a first and a second phase position comparison element input (25, 26), that the first phase position comparison element input (25) is connected to the first output terminal (13) of the transformation device (12) or the Angular position signal output (19) and the second phase position comparator input (26) is connected to the comparator output (23),and that the phase position comparator (24, 24') has a phase position comparator output (27) for outputting a phase position difference signal (Δφ). [2] Measuring device (1) according to claim 1, characterized by that the output terminals (13, 14) of the transformation device (12) are indirectly connected to the evaluation device (18) via a phase shift device (15), that the phase shift device (15) has a phase shifter output (16, 17) for each transformation signal for outputting a phase-shifted transformation signal shifted by a predetermined phase angle with respect to the relevant transformation signal, and that the phase shifter outputs (16, 17) are connected to the evaluation device (18) for generating the angular position signal. [3] Measuring device (1) according to claim 2, characterized bythat the evaluation device (18) for detecting a change in the phase position difference signal (Δφ) has a phase position difference signal monitoring device (28) connected to the phase position comparison element output (27). [4] Measuring device (1) according to claim 3, characterized by that the phase position difference signal monitoring device (28) has a comparison device (29) for comparing the change in the phase position difference signal (Δφ) with a tolerance band. [5] Measuring device (1) according to one of claims 1 to 4, characterized by that the magnetic field sensors (5, 6, 7) are designed as Hall, TMR, GMR or AMR sensors. [6] Measuring device (1) according to one of claims 1 to 5, characterized by that the magnetic field sensors (5, 6, 7) and the signal paths (11, 20) are implemented monolithically or hybridly integrated in a single encapsulated IC housing. [7] Measuring device (1) according to one of claims 1 to 5, characterized bythat the magnetic field sensors (5, 6, 7) and the signal paths (11, 20) are discretely implemented on a carrier. [8] Measuring device (1) according to one of claims 1 to 7, characterized by that the measuring device (1) has at least one modulation device (31, 32) which has a first input connected directly or indirectly via the phase shift device (15) to one of the output connections (13, 14) of the transformation device (12) and a second input connected to the comparator output (23) of the further signal path (20) as well as a modulation signal output (33, 35), and that the modulation signal output (33, 35) is connected to a demodulation device of the evaluation device (18) assigned to the modulation device (31, 32). [9] Measuring device (1) according to one of claims 1 to 8, characterized bythat the measuring device (1) for the sensor device (3) has at least one operating current modulation device (43), to the input of which the comparator output (23) of the further signal path (20) is connected, and that the evaluation device (18) is connected to an operating current demodulation device of the evaluation device (18) assigned to the operating current modulation device (43). [10] Method for determining an angular position signal, comprising a magnetic device (2) and a sensor device (3), in which the magnetic device (2) and the sensor device (3) are mounted so as to be rotatable relative to one another about a rotation axis (4), wherein the sensor device (3) has a number of at least three magnetic field sensors (5, 6, 7) arranged at an angle of rotation relative to one another with respect to the rotation axis (4) for generating mutually phase-shifted magnetic field measurement signals, wherein the magnetic field measurement signals are transformed into a plurality of phase-shifted transformation signals which are smaller than the number of magnetic field sensors (5, 6, 7), and wherein the angular position signal is generated with the aid of the phase shift signals thus obtained, characterized bythat the magnetic field measurement signal of at least one magnetic field sensor (5, 6, 7) or a combination of the magnetic field measurement signals of several magnetic field sensors (5, 6, 7) is compared with a threshold value signal to generate a digital comparison value signal (22), and that to detect a phase error the phase position of at least one transformation signal or the phase position of the angular position signal is compared with the phase position of the digital comparison value signal (22). [11] Method according to claim 10, characterized by that the magnetic field measurement signals are first transformed into the mutually phase-shifted transformation signals, that these are then each shifted by a predetermined phase angle, and that the angular position signal is generated as a function of the phase-shifted transformation signals thus obtained. [12] Method according to claim 10 or 11, characterized bythat to generate a phase difference signal (Δφ) - the difference between the phase position of at least one transformation signal and the phase position of the digital comparison value signal (22) or - the difference between the phase position of the angular position signal and the phase position of the digital comparison value signal (22) is formed and the change in the phase position difference signal (Δφ) is detected. [13] Method according to claim 12, characterized by that the change in the phase difference signal (Δφ) is compared with a tolerance band, and that an error signal is generated depending on the result of this comparison. [14] Method according to one of claims 10 to 13, characterized bythat the angular position signal is generated in an evaluation device (18), that in the evaluation device (18) the phase position of the digital comparison value signal (22) is compared with the phase position of at least one transformation signal, that the sensor device (3) is supplied with an operating current via the evaluation device (18), and that the digital comparison value signal (22) is transmitted from the sensor device (3) to the evaluation device (18) by modulating the operating current and is restored in the latter by demodulation of the operating current. [15] Method according to one of claims 10 to 13, characterized bythat the angular position signal is generated in an evaluation device (18), that in the evaluation device (18) the phase position of the digital comparison value signal (22) is compared with the phase position of at least one transformation signal, that the transformation signals are transmitted as differential signals to the evaluation device (18), and that the digital comparison value signal (22) is transmitted to the evaluation device (18) by modulating the DC components of the transformation signals and is restored in the evaluation device by demodulation of the DC components.

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