Method, computer program and device for checking sensing components

Abstract

An embodiment of the present disclosure relates to a method (100) particularly for checking mechanical stress acting on an induction component (210). The method (100) includes: detecting (110) one or more measurement variables related to mechanical stress when an electrical excitation signal is applied to the induction component (210). The method (100) further includes: determining (120) the mechanical stress acting on the induction component (210) based on the one or more detected measurement variables.

Description

Technical Field

[0001] Embodiments of the present invention relate to a method, a computer program, and a device for inspecting an induction component. Specifically, embodiments of the present invention relate to a method, a computer program, and a device for inspecting stress on a coil of an induction component. Background Art

[0002] In an induction furnace, a coil generates an electromagnetic field for inductively heating a molten charge. The electromagnetic field can interact with the coil, such that the electromagnetic field exerts axial and radial forces on the coil. To prevent the resulting coil movement and / or deformation / distortion, it can be mechanically fixed and pre-tensioned. A reduction or even loss of the pre-tension and the resulting possible movement or deformation of the coil during operation can have a self-reinforcing effect, which can damage or destroy the coil itself and other components of the induction furnace. This can, for example, reduce the service life of the crucible of the induction furnace. Alternatively or additionally, such effects can also lead to a reduction in the service life of the coil and its concrete anchor, by means of which the coil is fixed in the induction furnace.

[0003] Known processes for ensuring the pre-tension of the coil provide for checking the torque of the screw connection of the concrete anchor at predetermined time intervals and, if necessary, readjusting the torque.

[0004] Such a process for ensuring the pre-tension of the coil may involve additional work during coil operation.

[0005] In view of this, the object of the present invention can be regarded as presenting an improved concept for inspecting mechanical stress acting on an induction component. Summary of the Invention

[0006] To achieve the above object, the present disclosure presents independent claims and dependent claims.

[0007] According to a first aspect, embodiments of the present disclosure relate to a method for inspecting mechanical stress acting on an induction component in particular. The method includes: detecting one or more measurement variables related to mechanical stress when an electrical excitation signal is applied to the induction component. The method further includes: determining the mechanical stress acting on the induction component based on one or more detected measurement variables.

[0008] An induction component can particularly be understood as an electrical component or circuit applicable to generating an alternating electromagnetic field based on the electromagnetic induction law. An induction component includes, for example, a transformer (“Trafo”) and / or a coil.

[0009] In some application examples, the induction component and / or a part of the induction component (such as a coil) can be mechanically fixed or supported, such that mechanical stress acts on the induction component. In some application examples, mechanical stress can be understood as mechanical pre-stress.

[0010] The electrical excitation signal can correspond to the electrical energy supply for operating the inductive component or to providing an electrical test signal for inspecting the inductive component. The electrical excitation signal is applied to the inductive component, for example, by a signal generator coupled to the inductive component. The electrical excitation signal is, for example, an alternating current / voltage signal.

[0011] When the electrical excitation signal is applied, the inductive component can generate an electromagnetic field. When the inductive component interacts with the electromagnetic field, the behavior of the inductive component characterized by the measurement variable can depend in particular on the mechanical stress acting on the inductive component. Therefore, based on one or more measurement variables, it is possible to infer in particular the mechanical stress acting on the inductive component.

[0012] One or more measurement variables are, for example, electrical or mechanical measurement variables that indicate the behavior of the inductive component when the inductive component interacts with the electromagnetic field generated by the inductive component. It should also be noted that if "measurement variable" is mentioned hereinafter, it refers to one or more measurement variables.

[0013] The measurement variable can have a specific ratio to the mechanical stress acting on the inductive component, so that the mechanical stress can be inferred when the ratio of the measurement variables is known. For example, a processor is used to determine the mechanical stress.

[0014] Such a process may require less effort than the known processes for ensuring coil pre-tensioning. Additionally, when inspecting the inductive component, costs and time can be saved in this way.

[0015] The mechanical stress acting on the inductive component can in particular characterize the wear effect and / or the malformation / deformation of the inductive component. Therefore, the wear effect and / or the malformation / deformation of the inductive component can also be determined in particular by the above method. The wear effect is, for example, the evaporation of the coil material from the coil of the inductive component or the plastic deformation of the coil during winding due to thermal effects.

[0016] In certain embodiments, one or more measurement variables include vibration information about the mechanical vibration of the inductive component when the electrical excitation signal is applied. Determining the mechanical stress can include determining the mechanical stress based on the vibration information.

[0017] The mechanical vibration of the inductive component is, for example, the effect of the interaction between the inductive component and the electromagnetic field it generates. The mechanical vibration can in particular depend on the mechanical stress acting on the inductive component. Therefore, the mechanical stress can be inferred from the vibration information about the mechanical vibration of the inductive component.

[0018] To detect the vibration information, it is preferably possible to measure the mechanical vibration without contacting and without affecting the electrical behavior of the inductive component.

[0019] In certain embodiments, the vibration information includes at least one of the frequency, spectrum, amplitude, or upper or lower harmonics of the mechanical vibration.

[0020] Depending on the mechanical stress, the overtones or undertones generated by the mechanical vibration of the frequency, spectrum, amplitude, and / or induction component may vary. Therefore, the mechanical stress can be determined based on the frequency, spectrum, amplitude, generated overtones, and / or undertones.

[0021] Optionally, the mechanical stress can be determined based on one of the above measurement variables. Optionally, their combination can be used to determine the mechanical stress more precisely or reliably.

[0022] In some embodiments, the method includes: detecting vibration information based on the airborne sound generated by the induction component.

[0023] In the context of the present disclosure, airborne sound can particularly be understood as the sound wave generated by the mechanical vibration of the induction component, and thus is, for example, the frequency or amplitude characteristic of the mechanical vibration of the induction component.

[0024] To measure the vibration information, an electroacoustic transducer such as a microphone is used to measure the airborne sound.

[0025] In this way, the mechanical stress can be determined without contact.

[0026] In some embodiments, the method includes: detecting vibration information based on the structure-borne sound generated by the induction component.

[0027] Structure-borne sound can refer to the sound propagating within the induction component or in other solids excited by the vibration of the induction component. Thereby, the structure-borne sound characterizes, for example, the frequency or amplitude of the mechanical vibration of the induction component and can be measured, for example, by an electromagnetic, electrodynamic, or piezoelectric pickup to detect the vibration information.

[0028] For example, compared with detecting vibration information based on the airborne sound generated by the induction component, detecting vibration information based on the structure-borne sound generated by the induction component is less susceptible to interference from noise.

[0029] In some embodiments, one or more measurement variables related to mechanical stress include the impedance of the induction component. Determining the mechanical stress can include determining the mechanical stress based on the impedance.

[0030] Alternatively or additionally, the vibration information can be measured based on an electrical excitation signal, for example, based on voltage, current, or the resulting impedance of the induction component. In this way, the mechanical stress acting on the induction component can be determined based on the impedance.

[0031] For example, the impedance is measured based on the voltage and current of the electrical excitation signal. An ammeter and a voltmeter can be used to measure the impedance.

[0032] In certain application scenarios, corresponding measuring instruments for measuring the current and voltage of the electrical excitation signal may already be provided. Thus, compared with the above application examples, no additional measuring instruments such as those for measuring solid-borne sound or air-borne sound are required.

[0033] To improve the reliability when determining the mechanical stress acting on the induction component, this can optionally be determined based on the impedance and vibration information about the mechanical vibration of the induction component.

[0034] In certain embodiments, determining the mechanical stress based on one or more measurement variables includes determining the mechanical stress based on a comparison of the electrical excitation signal with one or more measurement variables.

[0035] Due to the behavior of the induction component or the interaction between the induction component and the generated electromagnetic field, especially depending on the electrical excitation signal, it may be advantageous to determine the mechanical stress based on a comparison of one or more of the above measurement variables with the electrical excitation signal. For example, the mechanical stress can be determined based on the ratio of the voltage frequency and / or current intensity of the electrical excitation signal to the mechanical vibration frequency of the induction component. Optionally, to determine the mechanical stress, the voltage amplitude and / or current intensity can be compared with the amplitude of the mechanical vibration.

[0036] This can at least partially compensate for the influence of the electrical excitation signal on determining the mechanical stress.

[0037] In certain embodiments, the method further includes: determining one or more influencing variables that affect one or more measurement variables when applying the electrical excitation signal. Accordingly, determining the mechanical stress can include determining the mechanical stress based on one or more influencing variables and one or more measurement variables.

[0038] Influencing variables include, for example, environmental temperature, air humidity, and / or the temperature of the induction component. Such influencing variables can affect the electromechanical characteristics of the induction component, thereby affecting one or more measurement variables when applying the electrical excitation signal.

[0039] To at least partially compensate for the influence of the influencing variables and / or estimate errors when determining the mechanical stress acting on the induction component, the above influencing variables can also be utilized in addition to the measurement variables that depend on the mechanical stress when determining the mechanical stress.

[0040] In certain embodiments, the method further includes: through machine learning, using one or more measurement variables and one or more reference values regarding the mechanical stress of the induction component as input variables for machine learning, to form a data processing structure for determining the mechanical stress acting on the induction component based on one or more measurement variables.

[0041] In the context of the present disclosure, the reference values can be understood as training data, based on which, together with the above-mentioned measurement variables as input variables, a data processing structure can develop a model or algorithm for determining the voltage acting on the induction component, for example, through supervised learning, semi-supervised learning, unsupervised learning, or reinforcement learning.

[0042] The reference values are, for example, mechanically determined mechanical stress values. The reference values can be obtained, for example, from the screw torque that pre-tightens the coil turns of the induction component in the radial direction.

[0043] The data processing structure can be understood, for example, as a processor, a microcontroller, or any other programmable hardware component. In machine learning, the artificial neural network operated by the data processing structure can be adjusted.

[0044] Those skilled in the art can understand that through machine learning, the above-mentioned model can be specifically adapted to the environment of the required application scenario, thereby providing more accurate results for the mechanical stress acting on the induction component than any predetermined mechanical stress determination model.

[0045] In some embodiments, the induction component includes at least one coil, and mechanical stress acts on the coil. Correspondingly, the method may include: detecting one or more measurement variables related to mechanical stress when an electrical excitation signal is applied to the at least one coil. The method may also determine the mechanical stress acting on the at least one coil based on the one or more detected measurement variables.

[0046] The coil is, for example, configured as an induction coil or a transformer coil and is fixed under mechanical prestress by a fixed fastening.

[0047] In some embodiments, the at least one coil is configured to inductively heat the melt disposed inside the at least one coil when an electrical excitation signal is applied to the at least one coil.

[0048] The coil is, for example, designed as the induction coil of a furnace, which is arranged around the furnace crucible and is fixed under mechanical prestress by a fixing device.

[0049] If the induction coil lacks sufficient mechanical prestress, the mechanical behavior of the induction coil when an electrical excitation signal is applied to heat the melt will cause increased wear of the crucible. Therefore, the above method can be particularly used to ensure that the induction coil is sufficiently prestressed to reduce crucible wear.

[0050] In some embodiments, detecting one or more measured variables includes detecting one or more first measured values of one or more measured variables at a first moment and detecting one or more second measured values of one or more measured variables at a second moment, and determining mechanical stress includes determining mechanical stress based on a comparison of one or more first measured values with one or more second measured values.

[0051] In this way, the time distribution of the mechanical stress acting on the sensing component can be determined, so that, for example, the maintenance time can be determined.

[0052] In some embodiments, the method may further include: determining the maintenance requirement for the sensing component and / or one or more elements coupled to the sensing component based on one or more measured variables.

[0053] For example, the deviation of the mechanical stress from a target value or a threshold value can be determined based on the above-mentioned measured variables, thereby obtaining the maintenance requirement of the sensing component. The maintenance requirement determined thereby indicates, for example, whether the sensing component or the elements interacting with the component must be replaced or repaired.

[0054] According to another aspect, an embodiment of the present disclosure relates to a computer program adapted to execute the above method when running on a processor.

[0055] Optionally, the computer program can, for example, control the application of an electrical excitation signal to the sensing component and detect one or more measured variables, and can also be used to determine the mechanical stress acting on the sensing component.

[0056] It goes without saying that the program may include a plurality of interacting subroutines, which generally can run on individual processors.

[0057] According to yet another aspect, an embodiment of the present disclosure relates to a device for inspecting mechanical stress on a sensing component. The device includes one or more sensors for detecting one or more measurement variables related to mechanical stress when an electrical excitation signal is applied to the sensing component. The device further includes at least one processor for determining the mechanical stress acting on the sensing component based on one or more detected measurement variables.

[0058] As described above, one or more sensors may include electroacoustic transducers, microphones, pickups, ammeters, and / or voltmeters to measure one or more measured variables or the values of one or more measured variables.

[0059] It should also be noted that if "sensor" is mentioned hereinafter, it refers to one or more sensors.

[0060] The sensor(s) can be coupled to the at least one processor in a wireless or wired manner to transmit the detected measurement variables to the processor to determine the mechanical stress acting on the sensing component.

[0061] A processor is understood, for example, as a central processing unit (ZVE, i.e., "Central Processing Unit - CPU"), a microcontroller, an integrated circuit, an application - specific integrated circuit (i.e., "Application - Specific Integrated Circuit - ASIC") or any programmable hardware.

[0062] The processor can be configured to determine the stress acting on the sensing component based on the relationship or ratio between the measured variable and the mechanical stress.

[0063] In some embodiments, one or more measured variables include vibration information regarding the mechanical vibration of the sensing component when an electrical excitation signal is applied. Accordingly, at least one processor can be configured to determine the mechanical stress based on the vibration information.

[0064] As described above, the vibration information can include at least one of the frequency, spectrum, amplitude, or upper or lower overtones of the mechanical vibration.

[0065] In some embodiments, one or more measured variables related to mechanical stress include the impedance of the sensing component. Accordingly, at least one processor can be configured to determine the mechanical stress based on the impedance.

[0066] As described above, the impedance can be determined based on the voltage and current of the electrical excitation signal.

[0067] It should be noted that the relevant features of the above - mentioned method can be transferred to a computer program and / or device with necessary modifications, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Some examples of the device and / or method are illustrated below with reference to the drawings. In the figures:

[0069] Figure 1 A schematic representation flowchart of a method for checking the mechanical stress acting on a sensing component is shown;

[0070] Figure 2a A schematic representation side view of a coil and the axial force acting on the coil is shown;

[0071] Figure 2b A schematic representation top view of a coil and the radial force acting on the coil is shown;

[0072] Figure 3 The measurement of the mechanical vibration of the sensing component is shown;

[0073] Figure 4a A schematic representation block diagram of a process for obtaining measured variables to determine the mechanical stress acting on a sensing component is shown;

[0074] Figure 4b A block diagram showing the influencing variables when determining mechanical stress;

[0075] Figure 5a A spectrogram showing the mechanical vibration of the sensing component;

[0076] Figure 5b A spectral analysis is shown;

[0077] Figure 5c Determining the fundamental tone based on the spectrum is shown;

[0078] Figure 5d Determining the fundamental tone and its upper partials is shown;

[0079] Figure 6 A time distribution diagram showing a plurality of time - sequential spectra representing the mechanical vibration of the sensing component;

[0080] Figure 7 An apparatus for checking the mechanical stress acting on the sensing component is shown. Detailed Description of the Invention

[0081] Various examples will now be described in detail with reference to the accompanying drawings, in which some examples are shown. In the drawings, for clarity, the thicknesses of lines, layers, and / or regions may be exaggerated.

[0082] Accordingly, while other examples are capable of various modifications and alternative forms, some specific examples are shown in the drawings and described in detail below. However, such detailed descriptions do not limit other examples to the specific forms described. Other examples may cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure. The same or similar reference numerals refer to the same or similar elements throughout the detailed description section, and these elements may be implemented in the same or modified forms when compared with each other, while providing the same or similar functions.

[0083] It should be understood that when an element is referred to as being "connected" or "coupled" to another element, these elements may be directly connected or coupled, or may be connected or coupled via one or more intermediate elements. When combining two elements A and B using "or", it should be understood that all possible combinations are disclosed, i.e., only A, only B, and A and B, unless otherwise explicitly or implicitly defined. Alternative phrasings for the same combination are "at least one of A and B" or "A and / or B". This also applies to combinations of more than two elements.

[0084] The terms used in this document to describe special cases are not intended to limit other instances. If in the singular form, such as when using "a", "an", and "the" and there is only a single element without being explicitly or implicitly defined as mandatory, other instances may also use multiple elements to implement the same function. When the function is described below as being implemented using multiple elements, other instances may use a single element or a single processing entity to implement the same function. It should also be understood that the terms "include" and / or "comprise", when used, indicate that the specified features, integers, steps, operations, processes, elements, components, and / or combinations thereof are specified but do not preclude the presence or addition of any other features, integers, steps, operations, processes, elements, components, and / or combinations thereof.

[0085] All terms, including technical terms, are used in this document in their ordinary meanings in the field to which the instances belong, unless otherwise defined.

[0086] Figure 1 A schematic representation flowchart of method 100 for checking mechanical stress acting on an inductive component is shown.

[0087] Method 100 includes: detecting 110 one or more measurement variables related to mechanical stress when an electrical excitation signal is applied to the inductive component.

[0088] Method 100 further includes: determining 120 the mechanical stress acting on the inductive component based on one or more detected measurement variables.

[0089] As Figure 2a and Figure 2b shown, the inductive component includes, for example, coil 210. When an electrical excitation signal is applied, the expansion force 214 acting (intrinsic / endogenous) in the axial direction can act on coil 210 by overcoming the prestress 212 acting in the axial direction. In addition, when an electrical excitation signal is applied, the expansion force 218 acting (intrinsic / endogenous) outward in the radial direction can act on coil 210 by overcoming the prestress 216 acting inward in the radial direction.

[0090] To support coil 210 in overcoming force 214 and / or force 218, coil 210 can be preloaded with mechanical stress in the axial direction and / or the radial direction. For this purpose, coil 210 is, for example, clamped with mechanical stress / prestress between anchors (concrete anchors) located radially outside or inside coil 210 by means of screws or bolts.

[0091] As described above, in order to determine the maintenance requirements and / or wear of coil 210, it may be necessary to check / monitor the mechanical stress / prestress of coil 210.

[0092] Method 100 allows for the mechanical stress to be monitored based on sensors and / or automatically.

[0093] In order to detect the measurement variables related to mechanical stress, the mechanical vibrations or the vibration information emitted by the coil 210 can be detected by means of a measuring technique. The vibration information can comprise at least a part of the measurement variables related to mechanical stress and can be detected, for example, based on the solid-borne sound or airborne sound generated by the coil 210 when an electrical excitation signal is applied to the coil 210.

[0094] Figure 3 The line graph 300 of the measurement signal 310 when measuring the mechanical vibrations of the coil 210 is shown as an example. The measurement signal 310 is plotted with respect to the axis 322 indicating the amplitude S of the measured solid-borne sound or airborne sound and the time axis 324 indicating the time t. The measurement signal 310 can be used to determine the vibration information or the so-called "frequency content", such as the frequency, amplitude, spectrum and / or lower harmonics and / or upper harmonics of the mechanical vibrations of the coil 210, which especially depends on the mechanical stress acting on the coil 210 and can thus be used to determine the measurement variables of the mechanical stress.

[0095] In addition to the solid-borne sound and / or airborne sound generated by the coil 210, the vibration information can be detected based on the excitation mechanism of the coil 210. The excitation mechanism includes, for example, supplying electrical energy to the coil 210 in the form of an electrical excitation signal - thus, the frequency content / vibration information can be derived from electrical variables (such as the voltage and current of the electrical excitation signal applied at the coil 210, etc.). Correspondingly, the voltage, current of the electrical excitation signal or the impedance of the coil 210 generated by the voltage and current can be used to determine the mechanical stress.

[0096] Furthermore, the impedance is characterized by an inductance depending on the cross-section of the coil 210 (depending on the shape and diameter of the coil 210). In this way, it is possible to determine the change in the cross-section caused by the change in mechanical stress based on the impedance and thus determine the mechanical stress acting on the coil 210.

[0097] The impedance and the vibration information can be stored in an electronic data memory and a processor designed for this purpose is used to analyze the frequency content of the mechanical vibrations. As will be described below with reference to Figure 4a and Figure 4b It is possible to detect and store the mechanical vibrations and further process / prepare the frequency content (for example in the form of a spectrum) at fixed (possibly overlapping) intervals or continuously / constantly at random.

[0098] Figure 4a A schematic block diagram showing the process for obtaining the measurement variables (such as the above-mentioned vibration information) which are suitable for determining the mechanical stress acting on the inductive component is shown.

[0099] This process provides for the detection of a 410 analog measurement signal from which a measured variable can be determined.

[0100] For digitization 420, the measurement signal can be converted in an analog-to-digital converter. The input measurement signal can be digitized continuously or at fixed or variable time intervals randomly. In the case of continuous digitization, for example, the measurement signal is digitized over the entire or a partial time period of the measurement signal. In the case of random digitization, for example, individual measured values of the measurement signal are digitized. Digitization 420 includes "discretization" of the measurement signal in the value domain and the time domain.

[0101] In a further step, the partially digitized measurement signal or digitized measured values are assigned 430 to respective time periods or time blocks that overlap or do not overlap with each other. Optionally, an average value of the measured values or the partially digitized measurement signal assigned to the same time period can be formed.

[0102] The measurement signal (partial measurement signal), average value, or measured values of the measured variables that prepare and characterize the mechanical vibration of the coil 210 using the above steps can be transformed 440 into the frequency domain by a subsequent transformation. Transformation 440 includes, for example, a Fourier transform. The measured variable (for example, the measured amplitude of the mechanical vibration of the coil 210) can be represented and analyzed in the frequency domain (detailed below).

[0103] Figure 4b The block diagram shown schematically represents, in addition to the schematic representation of steps 410, 420, and 430, the detection 450 of an analog measurement signal from which an influencing variable can be determined. The influencing variable affects, for example, the physical properties of the coil 210 and / or characterizes interference during the detection of the measured variable, thereby affecting the measured variable detected for determining mechanical stress.

[0104] The influencing variables include, for example, ambient temperature, air humidity, and / or interference noise, which, for example, interfere with the airborne sound generated by the detection coil 210.

[0105] In Figure 4b In the method step 460 shown, similar to digitizing 420 the measured variable, the measurement signal of the influencing variable can be digitized. In another method step 470, it is assigned to a time period or time block, and optionally, in a subsequent method step 480, it is transformed into the frequency domain.

[0106] As Figure 4b As indicated by the arrows in, the results of the method steps 460, 470, and 480 for preparing / obtaining the influencing variable can be combined or merged with the corresponding results of steps 420, 430, or 440 for preparing the measured variable in order to at least partially compensate for the influence of the influencing variable on the measured variable.

[0107] For example, the interference noise spectrum generated according to method step 480 can be subtracted from the mechanical vibration spectrum of coil 210 obtained from the measurement signal 310 in order to at least partially compensate for the interference caused by the interference noise.

[0108] As will be described below with reference to Figures 5a to 5d As shown, the frequency content / vibration information can then be analyzed with respect to the occurrence part of the frequency content (such as tones and / or their overtones / undertones). For this purpose, measurement variables are detected and stored, such as the frequency or amplitude of the mechanical vibration of coil 210. By forming the ratio between the amplitudes of the different tones and / or overtones that occur, a variable can be determined that reflects a part of the current structural dynamic inherent behavior of coil 210 (and, if necessary, the components interacting with coil 210). As Figure 5d shown, any changes in the structural dynamic inherent behavior (such as due to changes in prestress) or their absence can be identified by comparing two or more such measurements / analyses.

[0109] Figure 5a 、 Figure 5b and Figure 5c shows a line graph 500 with an axis 522 for indicating the measured vibration amplitude A and an axis 524 for indicating the measurement frequency of the mechanical vibration of coil 210. The line graph 500 represents the digital spectrum 510 of the mechanical vibration of coil 210, which is determined from the measurement signal 310 using the above steps 410, 420, 430, and 440.

[0110] Based on the spectrum 510, the frequencies f1,..., f5 at which the spectrum 510 exhibits local maxima A(f1),..., A(f5) are determined, for example, by an algorithm or a computer program. The frequencies f1,..., f5 can in particular specify the fundamental tones, overtones (so-called "harmonics"), and / or undertones (so-called "subharmonics") generated by the mechanical vibration.

[0111] In order to determine the mechanical stress, the entire spectrum 510 and / or the local maxima A(f1),..., A(f5) can be compared with a reference spectrum and / or its local maxima detected under the condition of knowing the mechanical stress acting on coil 210.

[0112] For example, based on the solid-borne sound or airborne sound generated by coil 210 when an electrical excitation signal is applied, after setting a specific mechanical stress acting on coil 210, the spectrum of coil 210 is detected as a reference. In order to set a specific mechanical stress, for example, the screws used to load mechanical prestress on coil 210 are tightened with a predetermined torque.

[0113] From Figure 5cIt can be seen that the local maximum A(f1) indicates, for example, the fundamental tone of a mechanical vibration having a frequency f0.

[0114] Figure 5d A line graph 500’ is shown, in which the frequency spectrum 510 is plotted with respect to an axis 522 indicating the measured vibration amplitude and an axis 524’ indicating the ratio of the measured frequency to the fundamental tone frequency f0. The line graph 500’ shows that the frequencies f1,..., f5 of the local maxima A(f1) / A1,..., A(f5) / A5 are equal to the integers 1,..., 5 that are divisors of the fundamental tone frequency f0. The local maxima A2,..., A5 or their frequencies f2,..., f5 indicate the lower overtones / harmonics of the fundamental tone having the frequency f0. Conversely, the local maxima A1,..., A4 can be regarded as the upper overtones / harmonics of the lower overtones of the local maximum A5.

[0115] Therefore, the mechanical stress can in particular be determined based on the values and / or ratios of the fundamental tone and / or lower overtones and / or upper overtones.

[0116] Figure 6 A line graph 600 is shown, in which several such frequency spectra 510-1, 510-2,..., 510-N detected in chronological order are plotted with respect to an axis 522, 524’ for specifying the time t at which the frequency spectra 510-1, 510-2,..., 510-N are detected and an axis 526. The line graph 600 represents the time course of the mechanical vibration of the coil 210. The line graph 600 can also be referred to as a “spectrogram”.

[0117] Therefore, the change in the mechanical stress of the coil 210 over time can be determined based on the frequency spectra 510-1, 510-2,..., 510-N or based on the deviation of the frequency spectra 510-1, 510-2,..., 510-N.

[0118] The method 100 is suitable in particular in the form of the above-described embodiments for identifying / determining (temporal) structural dynamic changes associated with one or more of the following causes and / or effects:

[0119] ● Changes in the stress / prestress (up to the loss point) of an inductive component (such as the coil 210), for example caused by the inductive component being adjacent to one or more system elements;

[0120] ● Changes in the wall thickness of one or more system elements;

[0121] ● Changes in the layer thickness of various inner layers of one or more system elements;

[0122] ● Changes in the stiffness and / or damping of one or more system elements.

[0123] Therefore, the method 100 can also be understood as a measurement method for evaluating the mechanical prestress of machine components during operation.

[0124] In an application example where the coil 210 is used as an induction coil in a furnace, one or more system components are understood to be, for example, the anchor that sandwiches the induction coil therebetween and / or the crucible around which the induction coil is arranged.

[0125] In certain embodiments, mechanical stress can be determined when different electrical excitation signals are applied. The different electrical excitation signals, for example, have different applied voltage frequencies. This can at least partially reduce the influence of the electrical excitation signal when determining mechanical stress.

[0126] The above method can not only improve the operational reliability but also make more effective use of the service life / durability of the coil 210 and the components that interact with the coil 210.

[0127] Method 100 is applicable, for example, to identifying structural dynamic changes in an induction component and / or components (mechanically) coupled thereto. As described above, the induction component can be the induction coil of a furnace / induction furnace. Components (mechanically) coupled to the induction coil particularly include the armature for biasing the induction coil and the crucible arranged within the induction coil.

[0128] Alternatively, the method 100 for determining structural dynamic characteristics can be applied to other applications / application examples that employ one or more induction components. Other applications / application examples include:

[0129] ● Mechanical and plant engineering:

[0130] ○ Induction hardening

[0131] ○ Electric drives, including linear drives

[0132] ○ Generators

[0133] ○ Transformers

[0134] ○ (Switch) electromagnets

[0135] ○ Magnetic levitation bearings

[0136] ○ Computed tomography (CT)

[0137] ○ Metal detectors

[0138] ○ Electric rockers

[0139] ○ Particle accelerators:

[0140] □ Linear acceleration; or

[0141] □ Circular acceleration (along a spiral or rose or circular closed trajectory)

[0142] □ In the following facilities:

[0143] ● Radiation sterilization

[0144] ● Food irradiation

[0145] ● Electron beam welding

[0146] ● X-ray lithography

[0147] ● Electron beam lithography

[0148] ● Radiation inspection

[0149] □ In a mass spectrometer

[0150] ● Medical technology:

[0151] ○ Magnetic resonance tomography

[0152] ○ Computed tomography (CT)

[0153] ○ Particle accelerator in a radiotherapy facility

[0154] ○ Magnetic therapy facility

[0155] ● Transmission:

[0156] ○ Electric drive, including linear drive

[0157] ○ Electromagnetic levitation system

[0158] ○ Electric levitation system

[0159] ● Defense technology:

[0160] ○ Gauss gun

[0161] ○ Railgun (more precisely electromagnetic railgun / EMRG, German railgun or rail cannon)

[0162] Figure 7 There is shown a device for inspecting mechanical stress on an inductive component, which is configured to perform the above method 100. The device includes sensors 710-1 and 710-2 for detecting a measurement variable depending on mechanical stress when an electrical excitation signal is applied to the inductive component. In the illustrated example, the inductive component includes a coil 210. The device further includes a processor 720 for determining the mechanical stress acting on the coil 210 based on the detected measurement variable.

[0163] The electrical excitation signal is applied to the coil 210 by a signal generator 730 coupled to the coil 210.

[0164] The sensor 710-1 is, for example, a microphone suitable for measuring airborne sound generated by the coil 210 when the electrical excitation signal is applied, to detect vibration information regarding the mechanical vibration of the coil 210 based on the measured airborne sound.

[0165] The sensor 710-2 includes, for example, an ammeter and a voltmeter for determining the impedance of the coil 210 based on an electrical excitation signal.

[0166] The sensors 710-1 and 710-2 are coupled to the processor 720 to transmit the vibration information and the measured impedance to the processor 720. As described above, the processor 720 can be configured to determine the mechanical stress acting on the coil 210 based on the vibration information and / or based on the impedance. To this end, the processor 720 can run a computer program suitable for this purpose, which can use the vibration information and the measured impedance as input values to determine the mechanical stress acting on the inductive component at least within the measurement error and / or measurement tolerance range.

[0167] The ideas and features described in connection with one or more of the examples detailed above and the figures can also be combined with one or more other examples to replace the same features of other examples or to supplement other examples with additional features.

[0168] The examples can also include or relate to a computer program containing program code for performing one or more of the above methods when the computer program is executed on a computer or a processor. The steps, operations, or processes of the various methods described above can be performed by a programmed computer or processor. The examples can also cover a program storage device, such as a machine-readable, processor-readable, or computer-readable digital data storage medium, which encodes a machine-executable, processor-executable, or computer-executable instruction program. The instructions execute or facilitate the execution of some or all of the steps of the above methods. The program storage device can, for example, include or be a digital memory, a magnetic storage medium (such as disks and tapes), a hard disk drive, or an optically readable digital data storage medium. Other examples can also cover a computer, a processor, or a controller programmed to perform the steps of the above methods or a (field) programmable logic array ((F)PLA) or a (field) programmable gate array ((F)PGA=(Field)Programmable Gate Arrays) programmed to perform the steps of the above methods.

[0169] The specification and the figures only represent the principles of the present disclosure. In addition, all the examples provided herein are clearly and expressly intended only for illustrative purposes in principle, to assist the reader in understanding the principles of the present disclosure and the concepts contributed by the inventors to advance the art. All statements regarding the principles, ideas, and examples of the present disclosure and their specific examples herein include their equivalent concepts.

[0170] A functional block referred to as a "device for..." performing a specific function can refer to a circuit configured to perform the specific function. Thus, a "device for something" can be implemented as a "device constructed or adapted for something", for example, a part or a circuit constructed or adapted for the corresponding task.

[0171] Each functional block of the functions of the various elements shown in the figure (including those referred to as "device", "signal providing device", "signal generating device", etc.) can be in the form of dedicated hardware (such as "signal provider", "signal processing unit", "processor", "controller", etc.) and implemented as hardware capable of executing software in combination with relevant software. In the case where a processor provides the function, the function can be provided by a single dedicated processor, a single shared processor, or multiple separate processors, some or all of which can be shared. However, the term "processor" or "controller" is far more than just hardware that can only run software, and can also include digital signal processor hardware (DSP hardware, DSP = Digital Signal Processor), network processors, application specific integrated circuits (ASIC = Application Specific Integrated Circuit), field programmable gate arrays (FPGA = Field Programmable Gate Array), read only memory (ROM = Read Only Memory) for storing software, random access memory (RAM = Random Access Memory), and non-volatile storage devices (Storage). Other hardware can also be covered, namely conventional hardware and / or custom hardware.

[0172] A block diagram can represent, for example, a high-level circuit diagram implementing the principles of the present disclosure. Similarly, a flowchart, program diagram, state transition diagram, pseudocode, etc. can represent various processes, operations, or steps, such as being substantially embodied in a computer-readable medium and then executed by a computer or processor, regardless of whether such a computer or processor is explicitly shown or not. The methods disclosed in the specification or claims can be implemented by components including means for performing each step of those methods.

[0173] It should be understood that the disclosure of multiple steps, processes, operations, or functions in the specification or claims should not be construed as being designed in a particular order, unless otherwise explicitly or implicitly stated, for example, for technical reasons. Therefore, the disclosure of multiple steps or functions is not limited to a particular order, unless these steps or functions are not interchangeable for technical reasons. In addition, in certain instances, a single step, function, process, or operation can include and / or be divided into multiple sub-steps, sub-functions, sub-processes, or sub-operations. Such sub-steps can be included and form part of the disclosure of that sub-step, unless explicitly excluded.

[0174] In addition, the appended claims are hereby incorporated into the specification, where each claim can exist independently as a separate instance. Although each claim can exist independently as a separate instance, it should be noted that although dependent claims in the claims may relate to a particular combination with one or more other claims, other instances also include combinations of dependent claims with the subject matter of each other dependent claim or independent claim. Such combinations are expressly set forth herein, unless a particular combination is not intended to be adopted as otherwise stated. In addition, the features of a claim are also intended to be included in any other independent claim, even if this claim is not directly dependent on the independent claim.

Claims

1. A method (100) for checking mechanical stress acting on a coil, the coil being configured as an induction coil or a transformer, the method (100) comprising: When an electrical excitation signal is applied to the coil, detecting (110) one or more measurement variables related to the mechanical stress acting on the coil, the one or more measurement variables including vibration information about the mechanical vibration of the coil when the electrical excitation signal is applied, wherein the detecting (110) of the measurement variables comprises: detecting the vibration information based on airborne sound generated by the coil; Based on one or more detected measurement variables, determining (120) the mechanical stress acting on the coil.

2. The method (100) according to claim 1, Among them, The one or more stress-related measurement variables further include the impedance of the coil; Wherein the determining (120) of the mechanical stress comprises determining the mechanical stress based on the vibration information and the impedance.

3. The method (100) according to any one of the preceding claims, wherein, The determining (120) of the mechanical stress based on one or more measurement variables comprises determining the mechanical stress based on a comparison of the electrical excitation signal with the one or more measurement variables.

4. The method (100) according to claim 1 or 2 above further comprises: Determining one or more influencing variables that affect the one or more measurement variables when the electrical excitation signal is applied, wherein determining the mechanical stress comprises determining the mechanical stress based on the one or more influencing variables and the one or more measurement variables.

5. The method (100) according to claim 1 or 2 above, the method further comprising: By machine learning, using the one or more measurement variables and one or more reference values regarding the mechanical stress of the coil as input variables of the machine learning, forming a data processing structure for determining the mechanical stress acting on the coil based on the one or more measurement variables.

6. The method (100) according to claim 1 or 2 above, wherein, At least one coil (210) is configured to inductively heat a melt disposed inside the at least one coil (210) when an electrical excitation signal is applied to the at least one coil (210).

7. The method (100) according to any one of the preceding claims 1 or 2, Among them, The detecting (110) of the one or more measurement variables comprises detecting one or more first measurement values of the one or more measurement variables at a first moment and detecting one or more second measurement values of the one or more measurement variables at a second moment; Wherein the determining (120) of the mechanical stress comprises determining the mechanical stress based on a comparison of the one or more first measurement values with the one or more second measurement values.

8. The method (100) according to claim 1 or 2 above, further comprising: Based on the one or more measurement variables, determining the maintenance requirements for the coil and / or one or more components coupled to the coil.

9. A program storage device for storing a computer program, the computer program being adapted to execute the method (100) according to any one of the preceding claims when run on a processor.

10. A device for checking mechanical stress on a coil, the coil being configured as an induction coil or a transformer, the device comprising: One or more sensors (710-1, 710-2) for detecting one or more measurement variables related to mechanical stress acting on the coil when an electrical excitation signal is applied to the coil, the one or more measurement variables including: vibration information about mechanical vibration of the coil when the electrical excitation signal is applied, wherein detecting the measurement variable includes: detecting the vibration information based on airborne sound generated by the coil; At least one processor (720) for determining mechanical stress acting on the coil based on one or more detected measurement variables.

11. The apparatus according to claim 10, Among them, The one or more stress-related measurement variables further include the impedance of the coil; Wherein the at least one processor (720) is configured to determine mechanical stress based on the vibration information and the impedance.

12. The apparatus according to claim 10 or 11, wherein, Determining mechanical stress based on one or more measurement variables includes: determining the mechanical stress based on a comparison of the electrical excitation signal with the one or more measurement variables.

Images