Method and graphical user interface for analyzing a mechanical object

Description

Technical field

[0001] Disclosed below are embodiments relating to a method and a device for analyzing the motion behavior of a mechanical object, for example, for analyzing the vibration behavior of an integrally manufactured impeller. Furthermore, graphical user interfaces configured for displaying and / or configuring one of the disclosed methods for analyzing the motion behavior of a mechanical object are disclosed. background

[0002] The measurement of mechanical objects, e.g. compressor wheels for turbines, can traditionally be carried out by exciting the object, which triggers a mechanical response from the object that can be measured as a time-dependent signal. To determine the mechanical properties of the object, e.g. its mass, damping and / or its natural frequencies and vibration modes, the time signal can be converted into the frequency domain and thus a corresponding transfer function can be designed, which in turn can be used as a model to provide information about the mechanical object properties and can be simulated. A measuring device for such a method is disclosed in DE 102009010375 A1. The Campbell diagram is traditionally used to illustrate the vibration properties of a mechanical system. In this diagram, the natural frequencies of the mechanical system are plotted against a rotational speed, e.g.the rotational speed of a rotating mechanical system component. In addition, the excitations acting on the system are also plotted. Critical resonance frequencies arise where a natural frequency and an excitation coincide. However, a mechanical system, e.g., a turbine compressor wheel, consists of several parts and exhibits complex vibration behavior during operation, which depends on various environmental parameters. The Campbell diagram can usually only represent part of such a complex vibration behavior. Further examples of methods that enable the analysis of mechanical objects are described in the documents US 2009 / 301055 A1 or WO 2007 / 071912 A2. Description

[0003] In contrast, the problem arises of improving the analysis of the movement behavior of a mechanical object.

[0004] This problem is solved by the invention, which is defined by the subject matter of the independent claims. The dependent claims relate to corresponding developments. Various aspects and embodiments of these aspects are disclosed below, providing additional features and advantages.

[0005] Some embodiments solve the problem of integrating different measurements into a diagram. To do this, various measurements, each differing in individual parameters, are merged into a single data set and displayed in a spectrogram. Additional information, such as analytically calculated natural frequencies or analytically calculated excitation frequencies, can then be superimposed on the merged measured values ​​in the spectrogram. This enables an effective analysis of the vibration behavior of a mechanical object.

[0006] A first aspect concerns a procedure comprising the steps: Carrying out a plurality of measurements of a mechanical movement by means of position-based methods and / or force-based methods at a plurality of measuring points on the mechanical object, wherein the measurements each differ in one or more parameters influencing the measurement, wherein the one or more parameters for differentiating the measurements comprise a rotational speed of the mechanical object;- Determining a spectrogram on the basis of measurement data of the measurements and depending on a predetermined parameter of the mechanical object, in particular for selecting a measurement date of a measurement;- Determining one or more excitations of the mechanical object, wherein the excitations are maximum amplitudes for the corresponding spectrogram.

[0007] A mechanical object can in particular be a disk or a disk-shaped object, which can in particular be unbalanced. In particular, a mechanical object can consist of a metal or of a plastic. In particular, a mechanical object can comprise a metal or a plastic. A mechanical object can in particular be a part of a turbine or a turbocharger. In particular, a mechanical object can be an impeller or comprise an impeller and in particular can be an impeller of a compressor stage of a turbine. In particular, a mechanical object can be a propeller or an impeller. However, a mechanical object can also be a musical instrument, in particular a percussion instrument, e.g. a tom-tom or a hi-hat.

[0008] Measurements are taken at a large number of measuring points. Additionally or alternatively, redundant measurements can also be performed, i.e. measurements taken multiple times at one and the same measuring point. In principle, all measurement methods for recording mechanical movement are suitable for this, in particular position-based methods and / or force-based methods. Measurements can therefore be carried out using position sensors, speed sensors, and acceleration sensors. Additionally or alternatively, measurements can also be carried out using force sensors, in particular strain gauges that are affixed to the corresponding measuring points. Movements and forces can also be recorded additionally or alternatively using piezoelectric sensors. Laser-based measurements, in particular laser vibrometric measurements, are also possible to perform one or more measurements.

[0009] One or more parameters in which two or more, in particular all, measurements or the associated measurement data differ can be parameters of the mechanical object and / or parameters of the environment in which the mechanical object operates. Such an environment can, in particular, be a machine in which the mechanical object is installed. If the mechanical object is a paddle wheel, a parameter for differentiating the measurements can, for example, result from a turbine in which the paddle wheel is used. One or more parameters for differentiating the measurements isa speed at which the mechanical object is operated or can therefore be in particular: a position of the measuring point; another acceleration situation in which the mechanical object finds itself, e.g. a turbine starting up or shutting down; an aerodynamic parameter, e.g. an aerodynamic pressure to which the mechanical object is exposed. For example, the mechanical object can be a paddle wheel or a blade of a paddle wheel. In this case, a parameter that differentiates the measurements can result from a different adjusted angle of the blades that is set during different measurements. The temperature of the mechanical object or the environment of the mechanical object can also be a parameter that varies between different measurements. Of course, a number of parameters can also be varied during different measurements.

[0010] A spectrogram can be determined, in particular, by transforming the individual measurements into partial spectrograms in an upstream process step. The partial spectrograms are then fused into a common spectrogram in a subsequent step. Alternatively, the measurement data can be fused in the time domain, and the fused data can be transformed into a spectrogram in a subsequent step. In a further alternative, measurement data from one or more, but not all, measurements can be fused in the time domain, and a first partial spectrogram can be created based on this. The remaining measurements can be transformed into individual further partial spectrograms, and these partial spectrograms can then be fused into a common partial spectrogram.Then the partial spectrograms containing both time-domain fused data and frequency-domain fused data can be merged into a common spectrogram.

[0011] A predetermined parameter depending on which the spectrogram or the partial spectrograms are created can in particular be an amplitude of the oscillation at the corresponding frequency. In this case, the amplitude at a specific frequency of the various measurements or measurement data from individual measurements at a specific point is compared and then the maximum amplitude is selected for the corresponding spectrogram. The parameter does not necessarily have to relate to the maximum amplitude. Alternatively, a minimum amplitude can also be selected and thus the measurement for the joint spectrogram or a partial spectrogram fused from several measurements can be selected which has the lowest amplitude at a specific frequency and at a specific time or at a specific time-dependent parameter value. Alternatively, a parameter can also relate to an average value or a statistical value, such as a variance.In order to determine comparative values ​​at individual positions in the spectrogram, interpolation between measurement data from individual or multiple measurements may be necessary. This will be explained in detail later.

[0012] In particular, one or more excitations of the mechanical object can already be determined during the various measurements. In particular, one or more interpolations between different measurement data and / or spectrogram data can also be carried out here in order to determine one or more excitations. For example, the measurement data in a partial spectrogram or the combined spectrogram can result in regions in which one or more excitations that occurred during the measurement to put the mechanical object into a dynamic state can be identified in the spectrogram and interpolated accordingly, so that the individual spectrogram values ​​belonging to an excitation are connected by a straight line that passes through the zero point of the spectrogram. This form is used in particular in the Campbell diagram.

[0013] Mapping the excitations in the spectrogram can, in particular, include a representation in a graphical user interface. Additionally or alternatively, such a mapping can also be based on a corresponding look-up table. Additionally or alternatively, mapping the excitations in the spectrogram can be model-based, i.e., measurement data and / or excitations displayed in the spectrogram can be functionally modeled so that they can be saved with less effort and visualized accordingly, for example, using a graphical user interface.

[0014] An embodiment of the first aspect relates to a method wherein the spectrogram is determined on the basis of a time or a time-dependent variable, in particular a rotational speed of the object or rotational speed of a part of the object.

[0015] A rotational speed of the mechanical object can in particular be a rotational speed of a turbine at which the mechanical object moves if it represents a blade wheel. In this case, the spectrogram is not displayed over time, but over this rotational speed, so that the frequency curves can be seen at different rotational speeds. In particular, a time or a time-dependent variable can be displayed non-linearly; in particular, sections can be displayed with a lower resolution if they contain less interesting sections of the spectrogram. Additionally and alternatively, sections can be displayed with a higher resolution, in particular with a higher time or rotational speed resolution. In this way, measurement data which has interesting sections can be displayed with a higher resolution.

[0016] Mapping in a spectrogram does not necessarily have to be a graphical mapping. Mapping can also involve mapping in computer memory, so that the fused measurement information can be accessed according to the structure of a spectrogram.

[0017] An embodiment of the first aspect relates to a method comprising the step: Mapping a, in particular analytical and / or simulative, prediction of a frequency or a frequency range of the mechanical object in the spectrogram.

[0018] In particular, further information can be superimposed on the joint spectrogram. This information can, for example, relate to natural frequencies of the mechanical object determined analytically and / or by simulation. By superimposing natural frequencies determined analytically or by simulation, the natural frequencies of the mechanical object obtained from the measurements can be easily compared in the spectrogram with the natural frequencies determined analytically or by simulation. This can, in particular, make it possible to detect measurement errors. An overlay of information determined analytically or by simulation can also relate to a partial spectrogram, in particular in order to identify areas of one or more partial spectrograms which contain measurement data that are to be removed before being fused into the joint spectrogram. This can, for example, apply to measurement data for which a comparison between analytically orSimulation-derived predictions indicate that the measurement data is inferior. These can then be removed to improve the quality of the fused spectrogram.

[0019] An embodiment of the first aspect relates to a method comprising the step: Interpolating the measurement information based on given reference points, in particular a grating in the spectrogram.

[0020] In particular, for merging partial spectrograms of individual or multiple measurement data sets, interpolation of frequency-based and / or time-based information based on the measurement data can be performed. In particular, the measurement data from individual and / or different measurements can be projected onto a common grid. This grid can have a very high resolution, i.e., a very fine mesh. If individual or multiple measurement data sets do not provide any information at the grid points, a corresponding measurement data point in the time domain or frequency domain is interpolated to the respective grid point.

[0021] An embodiment of the first aspect relates to a method comprising the steps: Comparing the measurement results of the individual measurements at one or more reference points; and selecting a measurement result or merging measurement results based on the compared measurement results and on the basis of a predetermined parameter.

[0022] The interpolated or measured information from individual measurements can then be compared at the individual points to perform a selection based on a predetermined parameter from the measurement data to be compared, as described above. For example, interpolated or measured information from different measurement data at a grid point may differ in their maximum oscillation amplitude, and according to the predetermined parameter, the measurement with the maximum oscillation amplitude can be selected for the joint / fused spectrogram.

[0023] An embodiment of the first aspect relates to a method comprising the step: Displaying points and / or areas of the spectrogram based on a predetermined criterion.

[0024] In order to reduce the complexity of the data mapped in a common spectrogram, specific regions or points in the spectrogram can be selected based on a predetermined criterion. In particular, such a predetermined criterion can comprise one or more regions in which a vibration amplitude exceeds a certain threshold value. Additionally or alternatively, the region or point with the maximum vibration amplitude mapped in the spectrogram can be displayed. Such a display can already be achieved by displaying the corresponding value. Additionally or alternatively, such a display can also comprise a color marking and / or a marking by a superimposed, geometric shape surrounding the corresponding region or point.The last-mentioned display options are useful when the spectrogram is displayed in a graphical user interface.

[0025] An embodiment of the first aspect relates to a method comprising the step: Filtering one or more measurement results before determining the spectrogram.

[0026] Filtering of one or more measurement results can be performed, particularly where the measurement results contain inferior measurement information. In particular, measurement results that excessively influence the fused spectrogram can be filtered out. Additionally or alternatively, erroneous measurement information can be filtered out. Filtering can encompass individual ranges or individual points of individual measurements. Additionally or alternatively, filtering can be applied to the entire measurement range of individual or multiple measurements, for example, high-pass filtering and / or low-pass filtering with a predetermined filter. High-pass filtering can be used, for example, to filter out ranges that do not differ significantly from one another.Low-pass filtering can be performed, for example, to filter out areas that differ too much from other areas, for example because they are based on faulty sensor information.

[0027] An embodiment of the first aspect relates to a method comprising the steps: in particular, manually selecting a point and / or region of the spectrogram; and displaying measurement results based on the point and / or region.

[0028] By merging measurement data into a partial spectrogram or a combined spectrogram based on a predetermined parameter, the measurement information of the individual measurements is no longer represented in the spectrogram. This problem can be solved by selecting a point and / or area in the spectrogram, which, for example, concerns an area and / or point with a maximum vibration amplitude, by making the individual measurement data represented in the selected area or point accessible by selecting it accordingly. For example, a point with a very high vibration amplitude can be selected in the spectrogram, and then the measurement, including the measurement data, at which this point was measured can be displayed.

[0029] An embodiment of the first aspect relates to a method comprising the steps: Selecting a region of the spectrogram; and Conduct a statistical analysis based on the information in this area.

[0030] Selected areas can be subjected to one or more statistical analyses. In particular, the statistical analyses can then be performed based on multiple measurement data items that were mapped in the corresponding area in the spectrogram. Furthermore, particularly when a graphical user interface is used, a corresponding switch can be used to select or switch between different statistical analyses so that the measurement information mapped in the selected areas can be statistically analyzed. A statistical analysis can, for example, include a histogram analysis of the measurement data mapped in the selected area. A statistical analysis can also include a maximum value analysis, a threshold value analysis, or an average value analysis, to which the data selected in the spectrogram is subjected.

[0031] An embodiment of the first aspect relates to a method wherein the spectrogram is determined on the basis of an integral transformation, in particular one of the following transformations: Fourier transform; sine transformation; cosine transformation; wavelet transform; Chirplet transform.

[0032] In particular, various integral transformations can be applied in the method. For example, in one step, one or more measurement data (from one or more corresponding measurements) can first be converted into a partial spectrum using a specific integral transformation, for example, a Fourier transform. Other measurement data (from other measurements) can be transformed into another partial spectrum using a different integral transformation, and these two partial spectra can be merged into a common spectrogram in a subsequent step. It is also possible, especially when a graphical user interface is used to display the spectrogram, to manually switch between different integral transformations so that the spectrogram depicts different analysis focuses depending on the selected integral transformation.

[0033] An embodiment of the first aspect relates to a method comprising the step: Displaying the spectrogram in a graphical user interface, in particular together with one or more of the following features: one or more of the predicted frequencies or frequency ranges; one or more common reference points and / or the interpolated points; a selected measurement result or a fused measurement result based on the compared measurement results; points or ranges determined based on a predetermined criterion; filtered points or ranges of the measurement results; a result of a statistical analysis; an integral transformation used.

[0034] An embodiment of the first aspect relates to a method comprising the steps: Selecting one or more values ​​in the frequency dimension and / or the time-dependent dimension of the spectrogram; displaying a history of the time-dependent dimension at the selected value(s) of the frequency dimension and / or a history of the frequency dimension at the selected value(s) of the time-dependent dimension.

[0035] Time-dependent information also includes time.

[0036] Another aspect relates to a graphical user interface (GUI) configured to display and / or configure an analysis of a motion behavior of a mechanical object according to the first aspect. Short description the Figures

[0037] Further advantages and features emerge from the following embodiments, which refer to the figures. The figures do not always show the embodiments to scale. The dimensions of the various features may be enlarged or reduced accordingly, particularly for the sake of clarity of the description. The following shows, partly schematically: Fig. 1 a spectrogram illustrating an analysis according to a disclosed embodiment, Fig. 2 another spectrogram illustrating an analysis according to a disclosed embodiment.

[0038] In the following descriptions, identical reference symbols refer to identical or at least functionally equivalent features.

[0039] In the following description, reference is made to the accompanying drawings, which form a part of the disclosure, and in which, by way of illustration, specific aspects in which the present disclosure may be understood are shown. It should be understood that other aspects and / or features may be utilized and functional, structural, or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense, since the scope of the present invention is defined by the appended claims.

[0040] In general, a disclosure about a described method also applies to a corresponding device for carrying out the method or a corresponding system comprising one or more devices, and vice versa. If, for example, a specific method step is described, a corresponding device may comprise a feature for carrying out the described method step, even if this feature is not explicitly described or illustrated in the figure. On the other hand, if, for example, a specific device is described on the basis of functional units, a corresponding method may comprise a step that carries out the described functionality, even if such steps are not explicitly described or illustrated in the figures. Likewise, a system may be provided with corresponding device features or with features for carrying out a specific method step.It is understood that features of the various exemplary aspects and embodiments described above or below may be combined with one another unless expressly stated otherwise. Description of the characters

[0041] The Figure 1shows a spectrogram to illustrate an analysis according to a disclosed embodiment. The spectrogram 100 relates to a map of the frequencies that occur on a blade of a rotating impeller in a turbine. Frequencies on the blade from 0 to approximately 10 kHz were measured. The frequencies are shown in the spectrogram over the revolutions of the impeller on which the blade is located. The revolutions can vary from 0 to approximately 7000 revolutions / min. The fused measurement data 105, 106 are already shown in the spectrogram 100. Regions 105 are shown in which various natural frequencies or vibration modes of the blades of the impeller are located. Furthermore, the excitations that were measured are also shown. These excitations can result, for example, from the aerodynamic influences that a blade exerts on the impeller.The fused spectrogram 100 results from three measurements 107, which are represented by the partial spectrograms 101, 102, and 103. The points 104 depicted in the partial spectrograms represent the acquired measurement signals after a short-time Fourier transformation.

[0042] The Figure 2 relates to an extended spectrogram 200 for illustrating an analysis according to a disclosed embodiment. The spectrogram 201 relates to measurement data that were merged from various individual measurements (not shown) and displayed as frequency representations over the respective set revolutions per minute. In addition to the Fig. 1In the spectrogram shown, the spectrogram 201 contains augmented information regarding the natural frequencies and the excitations. Analytically determined natural frequencies 203 are superimposed on the regions 105 in which various natural frequencies of the system become apparent from the measurement data. In addition, analytically determined excitations 202 were superimposed on the excitations, which were at least partially recorded by measurement, so that a quick comparison between the measured and fused information and the analytically calculated information regarding the natural frequencies and the excitations is possible. In addition, a region 205 was selected in which a particularly critical natural frequency can be assumed. Further analysis can be achieved with the projections of the frequency and amplitude curves. Diagram 207, which adjoins the spectrogram 201 in the lower area, reveals a rotation curve.This was assumed at a fixed frequency of 6000 Hz and shows a relative vibration amplitude related to a previously analytically determined maximum vibration value. The relative vibration amplitude is plotted against the various revolutions that the impeller can achieve. This shows that a particularly large vibration amplitude occurs in the range at just under 6000 revolutions per minute. If this range is reached or passed through during turbine operation, it must inevitably be dampened with additional measures to prevent accelerated material fatigue of the impeller due to the large vibration amplitudes that occur there. A similar diagram is shown adjacent to the right side of the spectrogram by diagram 206. It shows a frequency curve recorded at a rotational speed of 5000 revolutions per minute.This shows various local maxima that occur at the natural frequencies of the blade or impeller. In addition to the measurement data depicted in the spectrogram 201 or the analytical predictions of the natural frequencies, the previously measured vibration amplitude can also be precisely displayed in the projected diagram 206, also with regard to its absolute or relative value. This also leads to a faster and more flexible representation of the vibration behavior of the blade of the impeller. List of reference symbols

[0043] 100 Spectrogram for illustrating an analysis according to a disclosed embodiment 101 Measurement data of a first measurement in a partial spectrogram 102 Measurement data of a second measurement in a partial spectrogram 103 Measurement data of a third measurement in a partial spectrogram 104 Measurement data on natural frequencies and excitations in a spectrogram representation 105 Measured and fused measurement data of a mechanical object in a spectrogram representation 106 Measured and fused excitations of a mechanical object in a spectrogram representation 107 Fusion of several measurement data to form a spectrogram 200 Spectrogram for illustrating an analysis according to a disclosed embodiment 201 Spectrogram 202 Analytically determined excitations of a mechanical object 203 Analytically determined natural frequencies of the mechanical object 204 Maximum vibration amplitude selected from various measurement data 205 Selected range from the spectrogram 206 Vibration amplitude versus frequencyat a given number of revolutions 207 oscillation amplitude over the revolution at a given frequency

Claims

1. Method for analyzing a movement behavior of a mechanical object, comprising the steps of: - carrying out a plurality of measurements (101, 102, 103) of a mechanical movement by means of position-based methods and / or force-based methods at multiple measuring points on the mechanical object, wherein the measurements each differ in one or more parameters influencing the measurement, wherein the one or more parameters for differentiating the measurements comprise a rotational speed of the mechanical object; - determining a spectrogram (100) on the basis of measurement data (104) of the measurements (101, 102, 103) and according to a predetermined parameter of the mechanical object, in particular for selecting a measurement datum of a measurement; - determining one or more excitations (106) of the mechanical object, wherein the excitations are maximum amplitudes for the corresponding spectrogram; - mapping the excitations in the spectrogram (100).

2. The method according to the preceding claim, wherein the spectrogram (100) is determined on the basis of a time or a time-dependent variable, in particular a rotational speed of the object or rotational speed of a part of the object.

3. The method according to any of the preceding claims, comprising the step of: - mapping a prediction, in particular an analytical prediction, of a frequency (203) or a frequency range of the mechanical object in the spectrogram.

4. The method according to any of the preceding claims, comprising the step of: - interpolating the measurement data on the basis of common reference points, in particular a common grid in the spectrogram (100).

5. The method according to any of the preceding claims, comprising the steps of: - comparing the measurement data of the individual measurements at one or more reference points; and - selecting a measurement result or merging (107) measurement data (101, 102, 103) on the basis of the compared measurement data and on the basis of a predetermined parameter.

6. The method according to any of the preceding claims, comprising the step of: - displaying points and / or regions of the spectrogram (100, 200) on the basis of a predetermined criterion.

7. The method according to any of the preceding claims, comprising the step of: - filtering one or more measurement data from one or more measurements before determining the spectrogram (100, 200).

8. The method according to any of the preceding claims, comprising the steps of: - in particular manually selecting a point (205) and / or region of the spectrogram (100, 200); and - displaying measurement data (101, 102, 103) on the basis of the point and / or region.

9. The method according to any of the preceding claims, comprising the steps of: - selecting a region of the spectrogram (100, 200); and - carrying out a statistical analysis on the basis of measurement data in this region.

10. The method according to any of the preceding claims, wherein the spectrogram is determined on the basis of an integral transform, in particular a: - Fourier transform; - sine transform; - cosine transform; - wavelet transform; - chirplet transform.

11. The method according to any of the preceding claims, comprising the step of: - displaying the spectrogram (100, 200) in a graphical user interface, in particular together with one of the following features: - one or more of the predicted frequencies or frequency ranges; - one or more common reference points and / or the interpolated points; - points or regions determined on the basis of a predetermined criterion; - filtered points or regions of the measurement data; - a result of a statistical analysis; - an integral transform used.

12. Method according to any of the preceding claims, comprising the steps of: - selecting one or more values in the frequency dimension and / or the time-dependent dimension of the spectrogram (100, 200); - displaying a plot of the time-dependent dimension (207) at the selected value(s) of the frequency dimension and / or a plot of the frequency dimension (206) at the selected value(s) of the time-dependent dimension.

13. A graphical user interface designed to display and / or configure an analysis of a movement behavior of a mechanical object according to any of claims 1-12.