Self-test of an inertial sensor

Abstract

The invention relates to a measuring device with an inertial feedback sensor (1) and with a verification unit (3) for detecting a faulty sensor output signal (S) of the feedback sensor (1), which has a sensor element (5) and a reset element (7), wherein the verification unit (3) is configured to generate a dynamic test signal (T) acting on the reset element (7) with a frequency spectrum comprising a plurality of different frequencies, and to determine a dynamic transfer behavior of the feedback sensor (1) from a physical quantity to the sensor output signal (S) based on the sensor output signal (S) based on the measurement signal and on the basis of the test signal (T), and to compare the determined transfer behavior with a stored reference behavior, and to determine from the comparison whether a faulty sensor output signal (S) of the measuring device is present.

Description

[0001] The invention relates to a measuring device with an inertial feedback sensor and with a verification unit for detecting a faulty sensor output signal of the feedback sensor, as well as a method for performing a self-test of a measuring device with an inertial feedback sensor and with a verification unit for detecting a faulty sensor output signal of the feedback sensor.

[0002] The following information is based on expert considerations rather than necessarily derived from a specific state-of-the-art document: Inertial measurement units (IMUs) are used to record current kinematic quantities in a reference coordinate system. Mostly mechanical, they utilize known effects, such as the relationship between force and accelerated mass, the angular stability of rotating masses (gyroscopic stability), and similar phenomena, to determine usable sensor signals of prevailing kinematic quantities. A frequently essential component of an inertial measurement unit is, for example, a gyroscopic instrument. Such gyroscopic instruments serve to determine the orientation of a reference coordinate system in the form of angles, particularly relative to the Earth.The effect utilized here is the stability of a rotating mass with respect to changes in its orientation. For example, if a gimbal-mounted, rapidly rotating mass is attached to a moving body within a housing, a rotational movement of the body, and thus of the housing, causes the housing to rotate around the rotating mass, while the axis of the rotating mass maintains its orientation. From this relative change in orientation between the rotating mass and the housing, a change in orientation in the form of differential angles can be determined. Accelerometers are also typical components of inertial measuring devices, which utilize the inertia of the mass to measure the acceleration currently acting on the device.

[0003] Different approaches in the state of the art deal with a self-test function of such an inertial measuring device, or "IMU" for short.Some of these approaches focus specifically on capacitive sensors, such as DE 4133426 A1, which relates to a circuit arrangement for evaluating and testing a capacitive sensor, in particular for measuring acceleration, which has a deflectable center electrode between stationary measuring electrodes, with a measurement mode and a test mode, wherein in measurement mode the difference of measuring capacitances connected to the capacitance bridge, formed by the center electrode and each of the measuring electrodes, forms a signal for the deflection of the center electrode, and wherein in test mode a reference capacitance connected to the capacitance bridge replaces one of the measuring capacitances and a potential difference can be applied between the center electrode and the measuring electrode of the replaced measuring capacitance, wherein the deflection of the center electrode caused thereby can be measured at the other measuring capacitance.

[0004] US 5103667 A and US 5391283 A also focus specifically on capacitive sensors, while DE 19845185 A1 deals with vibration sensors.

[0005] Furthermore, it is necessary to place an actuating device near the sensor under test in order for the sensor to be tested. This applies to DE 19845185 A1 and US 5391283 A. Regarding the type of faults to be identified, various prior art documents address the dynamic identification of sensors, but generally with limited capability: DE 4133426 A1, US 5377523 A, and US 2008 / 0028823 A1 only mention testing at a specific frequency, which limits the parameters of the dynamic behavior that can be observed. DE 19845185 A1 recommends testing the sensor at different frequencies, but it does not provide any information on how the data can be used to assess the sensor's condition. In US 5103667 A, the test, which is performed on a capacitive accelerometer, is able to measure the damping characteristics of the sensor.However, how sensor integrity could be assessed using this method remains unclear.

[0006] DE 10 2022 202 581 A1 also relates to a test device for a sensor, comprising: a control device designed to apply test signals to the sensor and subsequently read the sensor in order to determine a sensor value, wherein the sensor is repeatedly applied the test signal for a predetermined first period of time and subsequently read the sensor for a predetermined second period of time, wherein the control device is further designed to vary the first predetermined period of time for applying the test signal to the sensor and to determine a corresponding sensor value for at least two different first periods of time, and wherein the control device is designed to determine a state value of the sensor using the determined sensor values ​​for at least two different first periods of time.

[0007] DE 10 2011 080 779 A1 also relates to a method for evaluating a passive sensor comprising the steps of: exciting the sensor with an excitation signal; transmitting a sensor signal resulting from the excitation and demodulating the transmitted sensor signal, wherein the power of the excitation signal with which the sensor is excited is distributed over a frequency interval.

[0008] The object of the invention is to make the operation of an inertial feedback sensor more reliable by improving a self-test function.

[0009] The invention is defined by the features of the independent claims. Advantageous further developments and embodiments are the subject of the dependent claims.

[0010] A first aspect of the invention relates to a measuring device with an inertial feedback sensor and with a verification unit for detecting a faulty sensor output signal of the feedback sensor, wherein the feedback sensor has a sensor element and a reset element configured to force the sensor element into an equilibrium state against an influence of a physical quantity to be measured experienced by the sensor element, and wherein the reset element has an output interface for outputting a measurement signal, wherein the verification unit is configured to generate, upon a trigger signal, a dynamic test signal acting on the reset element with a frequency spectrum comprising a plurality of different frequencies.and, based on the sensor output signal derived from the measurement signal and the test signal, to determine a dynamic transfer behavior of the feedback sensor from a physical quantity to the sensor output signal, to compare the determined transfer behavior with a stored reference behavior, and to determine from the comparison whether a faulty sensor output signal of the measuring device is present.

[0011] To quantify the physical quantity to be measured, an interaction with the feedback sensor is necessary. For this purpose, a sensor element is provided in the feedback sensor, upon which the physical quantity to be measured acts. This tends to force the sensor element into a deflection, which, depending on the design of the sensor element, can be electrical, mechanical, magnetic, etc. A restoring element counteracts this deflection by returning the sensor element, in the degree of freedom influenced by the physical quantity to be measured, to a state of equilibrium for the sensor element. For example, the deflection is caused mechanically by the physical quantity to be measured, i.e.,The sensor element tends to be deflected by a certain distance due to the physical quantity being measured, while the restoring element applies a counterforce to prevent this deflection and keep the sensor element at, for example, a local equilibrium point. If the counterforce is measured, an acceleration, for instance, can be inferred. Since the counterforce is thus a manipulated variable applied due to feedback, this type of sensor is called a feedback sensor.

[0012] The return element can be a passive component, such as a mechanical spring, or it can be a controllable actuator. The quantified action of the return element, in the sense of a reaction to the effect of the physical quantity, serves as the basis for generating the sensor output signal, which is based on the measurement signal of the return element. If a test signal is artificially introduced into this feedback loop affecting the return element, the measurement signal generated by the sensor is superimposed with the test signal, and the test signal acts on the return element as if it had been generated by the sensor due to an external physical influence that is to be measured. Accordingly, the return element will generate an opposing signal in the closed loop.

[0013] The verification unit can be implemented in a separate computer system, or, in an alternative embodiment, integrated with the feedback sensor in a single unit. If the verification unit then compares the generated test signal with the sensor output signal—which, unlike the regular operation of the feedback sensor without such a self-test, is based on the measurement signal and, in this case, the test signal—the transmission behavior of an acting physical quantity (which in this case does not actually occur but is simulated) on the sensor output signal can be transmitted. If the feedback sensor behaves linearly in this respect, an amplitude gain and a phase shift can be assigned to each existing frequency of a physical quantity on the sensor output signal.Accordingly, time-domain and, in particular, frequency-domain system identification methods can be used to determine the transmission behavior of the feedback sensor based on the test signal. This actual transmission behavior is then advantageously compared by the verification unit with a reference behavior in order to identify disturbances and undesired behavior, i.e., to detect so-called "soft errors" of the feedback sensor.

[0014] These represent a particular category of error cases where the feedback sensor continues to deliver data at the desired data rate, which may appear plausible to a human observer, but may be deviated from the actual value by an unacceptably large margin and thus only identifiable using specialized measurement techniques. However, by applying a dynamic test signal that acts on the reset element, the feedback sensor itself can be used to verify its correct function.

[0015] Key performance indicators (KPIs) can be determined that allow a comparison of the actual transmission behavior with the reference behavior. Since the test signal, in particular, is dynamic, exhibits a rich spectrum, and encompasses a sufficient number of frequencies in the feedback sensor to perform reliable system identification, KPIs such as frequency-dependent amplitude gain and frequency-dependent phase shift can be determined. Comparing these KPIs with corresponding predefined limits allows for a clear statement about the correct functioning of the feedback sensor, specifically whether it is functioning correctly or incorrectly.

[0016] This self-test is therefore advantageously able to independently check the proper functioning of one or more sensors of an inertial measurement unit and / or the evaluation electronics of the inertial measurement device. The proper functioning of an entire inertial measurement unit is often essential for the operation of a safety-critical flight control and navigation system of an aircraft, or at least for the proper execution of a mission.

[0017] Faults that impair proper functioning include not only a complete failure to output accurate and reliable measurement data, but also faults that cause changes in the dynamics of the inertial measuring device with respect to the transmission of a real state to the output sensor signal. The latter type of fault may not be immediately detected conventionally without complex technical testing and may require mechanical disassembly of the inertial measuring device for their detection.

[0018] The proposed self-test allows an inertial measurement device to provide reliable information about its condition, thus confirming its proper functioning. This makes an inertial measurement device reusable in systems that are traditionally not reusable or have not been reused, such as booster systems of launch vehicles or space shuttles returning to Earth on a regular basis.

[0019] According to an advantageous embodiment, the dynamic test signal comprises a sinusoidal signal with a frequency that changes over time.

[0020] In this embodiment, the test signal, which acts as an artificial disturbance in the closed loop of the feedback sensor, is continuously sinusoidal, while the frequency of the sinusoidal oscillation changes over time, particularly increasing. The advantage of such a sinusoidal test signal lies in its simple generation and the complete coverage of a wide frequency spectrum from a desired lowest to a desired highest frequency. If the test signal exhibits a sequence of frequencies that change at discrete intervals, it is also called a "sine sweep"; if the frequencies change continuously over time, it can be referred to as a "chirp signal."Alternatives to the sinusoidal test signal include a series of rectangular pulses of different durations, random or pseudo-random excitation, or other methods; the crucial factor in the excitation is a rich spectrum of excitation with a large number of different frequencies in the test signal in order to identify the most complete possible dynamic behavior of the feedback sensor within a desired frequency range.

[0021] According to a further advantageous embodiment, the dynamic test signal has a full period oscillation of a first sinusoidal signal with a first constant frequency, wherein the first sinusoidal signal is followed by a second sinusoidal signal with a frequency that changes over time.

[0022] The advantage of this combination of sinusoidal signals with an initial very low-frequency period followed by a frequency sweep as described above lies particularly in the fact that the initial low-frequency period is chosen to be so slow that it does not introduce any significant phase delay during the dynamic transmission to the sensor output signal. This can be helpful in analyzing the transmission behavior.

[0023] According to a further advantageous embodiment, the feedback sensor comprises a demodulator, a compensation unit, and an amplifier, and is configured to direct a sensor element signal, generated by the sensor element in response to the action of a physical quantity to be measured on the sensor element, to the demodulator and further to the compensation unit, wherein the verification unit is configured to add the test signal to an output signal of the compensation unit, wherein the feedback sensor is configured to direct the result of the addition to the amplifier, and wherein the amplifier is connected with its output to the feedback element.

[0024] The demodulator converts the signal generated by the sensor element into an electrical or digital signal that can be used, for example, for calculations. The compensation unit uses the demodulated signal to generate a control signal that forces the reset element to return the sensor element to a zero position. The amplifier converts the signal generated by the compensation unit into the physical value required by the reset element.

[0025] According to a further advantageous embodiment, the verification unit is designed to determine whether a faulty sensor output signal of the feedback sensor is present by forming at least one reference parameter based on the determined transmission behavior, which is then compared with a respective limit value.

[0026] According to a further advantageous embodiment, the comparison of the respective reference parameter with the respective limit value relates to a gain factor and / or a gain factor at a lowest frequency of the test signal and / or a bias and / or a bias at a lowest frequency of the test signal and / or a maximum bias deviation of a plurality of bias values ​​at different frequencies relative to a bias value at a lowest frequency and / or a maximum gain range between calculated gains and / or the frequency at which a 3dB drop in amplitude occurs in the transfer behavior and / or a phase shift at the 3dB drop in amplitude in the transfer behavior.

[0027] In particular, the gain factor and the bias at the lowest frequency of the test signal, as well as the maximum bias deviation of a multitude of bias values ​​at different frequencies relative to a bias value at the lowest frequency of the test signal, are especially relevant because they are proportional to, or at least correlated with, a scale factor or bias, especially a frequency-dependent bias caused by the correction of vibrations at the sensor element of the feedback sensor. These are all parameters that directly influence the performance of a navigation system that uses such a feedback sensor. The other parameters mentioned above do not directly influence the performance of the navigation system but represent the dynamic transfer characteristics of the feedback sensor.Unexpected changes in these parameters and key figures represent possible faulty sensor output signals, so-called "soft failures" or "soft errors", which must be identified and avoided.

[0028] According to a further advantageous embodiment, the verification unit is designed to check whether the trigger signal occurs during a non-safety-critical use of the measuring device and to discard the trigger signal if a safety-critical use is detected.

[0029] Accordingly, the self-test is advantageously performed, and the test signal generated and applied to the feedback sensor, only when the measuring device is not currently in use and is not in use for the duration of the test signal application. In an alternative embodiment, the trigger signal can be generated by the verification unit itself if the verification unit does not detect any safety-critical use. This could be the case, for example, when an aircraft equipped with such a measuring device is stationary on the ground.

[0030] Another aspect of the invention relates to a method for performing a self-test of a measuring device with an inertial feedback sensor and with a verification unit for detecting a faulty sensor output signal of the feedback sensor, wherein a feedback sensor is used which has a sensor element and a reset element which forces the sensor element into an equilibrium state against an influence of a physical quantity to be measured experienced by the sensor element and has an output interface for outputting a measurement signal, wherein the verification unit generates a dynamic test signal acting on the reset element in response to a trigger signal, with a frequency spectrum comprising a plurality of different frequencies.and based on the sensor output signal based on the measurement signal and on the test signal, a dynamic transfer behavior of the feedback sensor from a physical quantity to the sensor output signal is determined, and the determined transfer behavior is compared with a stored reference behavior, and from the comparison it is determined whether a faulty sensor output signal of the measuring device is present.

[0031] The embodiments and implementation variants mentioned under the first aspect of the invention may extend to further improvements and alternative embodiments of the aforementioned method for performing a self-test of such a measuring device. Advantages and preferred further developments of the proposed method result from an analogous and substantive transfer of the embodiments given above in connection with the proposed measuring device.

[0032] According to a further advantageous embodiment, the verification unit is designed to use at least one static, pre-stored limit value and to determine at least one further dynamic limit value based on the determined transmission behavior.

[0033] For example, a constant limit value can be used for the gain factor, while the gain factor determined during the self-test using the test signal serves as the basis for the current determination of a limit value for a detected bias.

[0034] According to a further advantageous embodiment, the determined transfer behavior includes a determined gain factor, wherein the verification unit is configured to determine a limit value with respect to at least one of the following using a predefined function and the determined gain factor as the input of the function: bias, bias deviation, maximum gain factor, frequency of a 3dB drop in the amplitude in the transfer behavior, phase delay at a 3dB drop in the amplitude in the transfer behavior.

[0035] According to a further advantageous embodiment, the determined transfer behavior includes a determined bias, wherein the verification unit is configured to determine a limit value with respect to at least one of the following using a predefined function and the determined bias as the input of the function: gain factor, bias deviation, maximum gain factor, frequency of a 3dB drop in the amplitude in the transfer behavior, phase delay at a 3dB drop in the amplitude in the transfer behavior.

[0036] The purpose of the verification unit is to determine whether the feedback sensor is generating a faulty output signal. False positives of a faulty sensor signal could be generated by the verification unit if environmental conditions change in such a way that the feedback sensor's transmission behavior also changes. Such a change in transmission behavior occurs, for example, due to a change in temperature or orientation relative to the ground and is not objectively considered faulty transmission behavior; rather, the feedback sensor is designed to operate under varying environmental conditions. The purpose of the two embodiments described immediately preceding this is to take such changes in environmental parameters into account when checking the feedback sensor for a faulty sensor output signal due to faulty transmission behavior.

[0037] The respective predefined function is determined accordingly during the manufacturing phase of the measuring device in order to establish limit values ​​for key figures that represent meaningful limit values ​​within certain operating ranges and do not lead to false positives in fault detection.

[0038] A further aspect of the invention relates to a method for manufacturing a measuring device with an inertial feedback sensor and with a verification unit for detecting a faulty sensor output signal of the feedback sensor, wherein a feedback sensor is provided with a sensor element and with a reset element, which is configured to force the sensor element into an equilibrium state against an influence of a physical quantity to be measured experienced by the sensor element, and wherein the reset element has an output interface for outputting a measurement signal, and wherein the verification unit is configured to generate, upon a trigger signal, a dynamic test signal acting on the reset element with a frequency spectrum comprising a plurality of different frequencies.and, based on the sensor output signal derived from the measurement signal and the test signal, to determine a dynamic transfer behavior of the feedback sensor from a physical quantity to the sensor output signal, and to compare the determined transfer behavior with a stored reference behavior by creating a reference parameter which is compared with a respective limit value, and to determine from the comparison whether a faulty sensor output signal of the measuring device is present, wherein at least one limit value is stored in the verification unit and the limit value is determined by determining a respective transfer behavior of the feedback sensor under a variety of different test conditions and statistically evaluating the transfer behaviors.

[0039] In this process, a feedback sensor with the aforementioned properties is initially provided. The core of the subsequent manufacturing process concerns the verification unit, for which a limit value is determined and stored. This limit value can then be used in the later operation of the measuring device for a self-test, as described above and below. The determination of at least one limit value is achieved by performing a system identification, specifically in the sense of such a self-test with a test signal, under various environmental conditions, such as different temperatures or orientations of the feedback sensor relative to the ground. Relevant data for each of these environmental conditions are stored for statistical evaluation.In particular, an expected value and a standard deviation of a given probability distribution are determined, and a corresponding limit is formed based on these.

[0040] Further advantages, features and details will become apparent from the following description, in which - possibly with reference to the drawing - at least one embodiment is described in detail.

[0041] They show: Fig. 1: A measuring device according to an embodiment of the invention. Fig. 2: An exemplary test signal for the self-test of a feedback sensor according to an embodiment of the invention. Fig. 3: A method for performing a self-test of a measuring device according to an embodiment of the invention.

[0042] The representations in the figures are schematic and not to scale.

[0043] Fig. Figure 1 shows a measuring device with an inertial feedback sensor 1 and a verification unit 3 for determining, in a self-test procedure, whether a sensor output signal S of the feedback sensor 1 contains an error. The feedback sensor 1 can be a rotation sensor or an acceleration sensor and has a corresponding sensor element 5, which utilizes the principle of inertia and / or gyroscopic stability to perform an inertial measurement. Furthermore, the feedback sensor 1 has a restoring element 7, which is designed to force the sensor element 5 into a position-related equilibrium state against the influence of a physical quantity to be measured, such as rotation or acceleration, experienced by the sensor element 5. The signal generated by the sensor element 5 is fed to a demodulator 9, the result of which is then directed to a compensation unit 11.The result of the compensation unit 11 can be added to the test signal T generated by the verification unit 3 during a self-test of the measuring device. The result of the addition is fed to an amplifier 13, the result of which in turn acts on the reset element 7. The control variable generated at the reset element 7 to force the sensor element 5 into its equilibrium state serves as the measurement signal and, in this simplified example, the . Fig. 1. This signal is directly used as the sensor output signal S of the feedback sensor 1. Using the S / T ratio, for example, by calculating cross-spectra and other methods known from system identification, amplitude gains, phase shifts, and especially key performance indicators can be determined. This allows the dynamic transfer behavior of the feedback sensor 1 to be determined using the test signal T as an artificial disturbance in the control loop, taking into account its effect on the sensor output signal S. This behavior can then be compared directly with a reference or indirectly via key performance indicators. For this purpose, the verification unit 3 generates the test signal T for the duration of a self-test of the measuring device.

[0044] Fig. Figure 2 shows an example of a dynamic test signal T in the form of a sinusoidal signal with a frequency that changes over time. This "frequency sweep" continuously traverses frequencies from a lowest to a highest frequency, thus fulfilling the requirement, frequently used in system identification, of a "rich excitation" of the dynamics of the system under investigation, in this case the feedback sensor 1.

[0045] Fig.Figure 3 shows a method for performing a self-test of a measuring device with an inertial feedback sensor 1 and with a verification unit 3 for detecting a faulty sensor output signal S of the feedback sensor 1, wherein a feedback sensor 1 S1 is used which has a sensor element 5 and a reset element 7 which forces the sensor element 5 into an equilibrium state against an action of a physical quantity to be measured experienced by the sensor element 5 and has an output interface for outputting a measurement signal, wherein the verification unit 3 generates a dynamic test signal T acting on the reset element 7 with a frequency spectrum comprising a plurality of different frequencies S2, upon a trigger signal.and based on the sensor output signal S based on the measurement signal and on the test signal T, a dynamic transfer behavior of the feedback sensor 1 from a physical quantity to the sensor output signal S is determined S3 and the determined transfer behavior is compared with a stored reference behavior S4, and from the comparison it is determined S5 whether a faulty sensor output signal S of the measuring device is present.

[0046] Although the invention has been further illustrated and explained in detail by means of preferred embodiments, the invention is not limited by the disclosed examples, and other variations can be derived from them by a person skilled in the art without departing from the scope of protection of the invention. It is therefore clear that a multitude of possible variations exist. It is also clear that the embodiments mentioned as examples are truly only examples and are not to be understood in any way as limiting, for example, the scope of protection, the possible applications, or the configuration of the invention.Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, whereby the person skilled in the art, with knowledge of the disclosed inventive concept, can make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, without leaving the scope of protection defined by the claims and their legal equivalents, such as further explanations in the description. Reference symbol list 1 feedback sensor 3 Verification Unit 5 sensor element 7 Reset element 9 Demodulator 11 compensation unit 13 amplifiers

Claims

[1] Measuring device with an inertial feedback sensor (1) and with a verification unit (3) for detecting a faulty sensor output signal (S) of the feedback sensor (1), wherein the feedback sensor (1) has a sensor element (5) and a reset element (7) which is configured to force the sensor element (5) into an equilibrium state against an action of a physical quantity to be measured experienced by the sensor element (5), and wherein the reset element (7) has an output interface for outputting a measurement signal, wherein the verification unit (3) is configured to generate, upon a trigger signal, a dynamic test signal (T) acting on the reset element (7) with a frequency spectrum comprising a plurality of different frequencies,and to determine, based on the sensor output signal (S) based on the measurement signal and on the test signal (T), a dynamic transfer behavior of the feedback sensor (1) from the physical quantity to the sensor output signal (S) and to compare the determined transfer behavior with a stored reference behavior, as well as to determine from the comparison whether a faulty sensor output signal (S) of the measuring device is present. [2] Measuring device according to claim 1, wherein the dynamic test signal (T) comprises a sinusoidal signal with a frequency that changes over time. [3] Measuring device according to claim 2, wherein the dynamic test signal (T) comprises a full period oscillation of a first sinusoidal signal with a first constant frequency, wherein the first sinusoidal signal is followed by a second sinusoidal signal with a frequency that changes over time. [4] Measuring device according to one of the preceding claims, wherein the verification unit (3) is configured to determine whether a faulty sensor output signal (S) of the feedback sensor (1) is present by forming at least one reference parameter on the basis of the determined transmission behavior by the verification unit (3), which is compared with a respective pre-stored limit value. [5] Measuring device according to claim 4, wherein the comparison of the respective reference parameter with the respective limit value relates to a gain factor and / or a gain factor at a lowest frequency of the test signal (T) and / or a bias and / or a bias at a lowest frequency of the test signal (T) and / or a maximum bias deviation of a plurality of bias values ​​at different frequencies relative to a bias value at a lowest frequency and / or a maximum gain range between calculated gains and / or the frequency of a 3dB drop in the amplitude in the transfer behavior and / or a phase shift at a 3dB drop in the amplitude in the transfer behavior. [6] Measuring device according to one of claims 4 to 5, wherein the verification unit (3) is configured to use at least one static prestored limit value and to determine at least one further dynamic limit value based on the determined transfer behavior. [7] Measuring device according to claim 6, wherein the determined transfer behavior comprises a determined gain factor, wherein the verification unit (3) is configured to determine a limit value with respect to at least one of the following using a predefined function and the determined gain factor as the input of the function: bias, bias deviation, maximum gain factor, frequency of a 3dB drop in the amplitude in the transfer behavior, phase delay at a 3dB drop in the amplitude in the transfer behavior. [8] Measuring device according to claim 6, wherein the determined transfer behavior comprises a determined bias, wherein the verification unit (3) is configured to determine a limit value with respect to at least one of the following using a predefined function and the determined bias as the input of the function: Gain factor, bias deviation, maximum gain factor, frequency of a 3dB drop in amplitude in the transfer behavior, phase delay at a 3dB drop in amplitude in the transfer behavior. [9] Method for performing a self-test of a measuring device with an inertial feedback sensor (1) and with a verification unit (3) for detecting a faulty sensor output signal (S) of the feedback sensor (1), wherein a feedback sensor (1) is used (S1) which has a sensor element (5) and a reset element (7) which forces the sensor element (5) into an equilibrium state against an action of a physical quantity to be measured experienced by the sensor element (5) and has an output interface for outputting a measurement signal, wherein the verification unit (3) generates a dynamic test signal (T) acting on the reset element (7) with a frequency spectrum comprising a plurality of different frequencies (S2) upon a trigger signal.and based on the sensor output signal (S) based on the measurement signal and on the test signal (T), a dynamic transfer behavior of the feedback sensor (1) from the physical quantity to the sensor output signal (S) is determined (S3), and the determined transfer behavior is compared with a stored reference behavior (S4), and from the comparison it is determined (S5) whether a faulty sensor output signal (S) of the measuring device is present. [10] Method for manufacturing a measuring device with an inertial feedback sensor (1) and with a verification unit (3) for detecting a faulty sensor output signal (S) of the feedback sensor (1), wherein a feedback sensor (1) is provided with a sensor element (5) and with a reset element (7) which is configured to force the sensor element (5) into an equilibrium state against an action of a physical quantity to be measured experienced by the sensor element (5), and wherein the reset element (7) has an output interface for outputting a measurement signal, and wherein the verification unit (3) is configured to generate, upon a trigger signal, a dynamic test signal (T) acting on the reset element (7) with a frequency spectrum comprising a plurality of different frequencies,and, based on the sensor output signal (S) based on the measurement signal and on the test signal (T), to determine a dynamic transfer behavior of the feedback sensor (1) from the physical quantity to the sensor output signal (S) and to compare the determined transfer behavior with a stored reference behavior by forming a reference parameter which is compared with a respective limit value, and to determine from the comparison whether a faulty sensor output signal (S) of the measuring device is present, wherein at least one limit value is stored in the verification unit (3) and the limit value is determined during the manufacture of the measuring device by determining a respective transfer behavior of the feedback sensor (1) under a variety of different test conditions and statistically evaluating the transfer behaviors.

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