Signal processing method, signal processing device, signal processing system, and signal processing program

Abstract

To provide a signal processing method capable of providing an index that enables a user to diagnose the presence or absence of an abnormality even when an unexpected abnormality occurs in a vibration state. [Solution] A signal processing method including the steps of: acquiring measurement data of a physical quantity caused by vibration of an object during a first period; acquiring measurement data of the physical quantity caused by vibration of the object during a second period different from the first period; and generating a Lissajous figure based on the difference between the measurement data during the first period and the measurement data during the second period.

Description

[Technical Field]

[0001] The present invention relates to a signal processing method, a signal processing device, a signal processing system, and a signal processing program. [Background technology]

[0002] Patent Document 1 describes an abnormality diagnosis device for a bearing part of a rotating equipment, which includes a vibration detection means for detecting vibrations at predetermined positions on at least two axes that are orthogonal to each other on the same plane centered on the axis of the rotating equipment and outputting a vibration waveform signal, a Lissajous waveform diagram generation means for generating a Lissajous waveform diagram based on both vibration waveform signals, a reference Lissajous waveform diagram setting means for setting and storing in advance a plurality of reference Lissajous waveform diagrams that are each assumed based on the cause of each abnormality, and an abnormality cause determination means for comparing the Lissajous waveform diagram with each reference Lissajous waveform diagram to determine and output the cause of the abnormality. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-258305 Summary of the Invention [Problem to be solved by the invention]

[0004] The method described in Patent Document 1 requires the time and effort of preparing in advance multiple reference Lissajous waveform diagrams that are each assumed to be the cause of each abnormality, and also determines the cause of the abnormality by comparing the Lissajous waveform diagram with each reference Lissajous waveform diagram and determining which one is most similar, making it difficult to determine whether or not an abnormality exists when an unexpected abnormality occurs. [Means for solving the problem]

[0005] One aspect of the signal processing method according to the present invention is to acquiring measurement data of a physical quantity caused by vibration of the object during a first period; acquiring measurement data of the physical quantity caused by vibration of the object during a second period different from the first period; generating a Lissajous figure based on a difference between the measurement data in the first period and the measurement data in the second period; Includes.

[0006] One aspect of the signal processing device according to the present invention is a measurement data acquisition circuit that acquires measurement data of a physical quantity caused by vibration of an object during a first period and measurement data of the physical quantity caused by vibration of the object during a second period different from the first period; a Lissajous figure generating circuit that generates a Lissajous figure based on a difference between the measurement data in the first period and the measurement data in the second period; Equipped with.

[0007] One aspect of the signal processing system according to the present invention is An aspect of the signal processing device; a physical quantity sensor that detects the physical quantity; Equipped with.

[0008] One aspect of the signal processing program according to the present invention is acquiring measurement data of a physical quantity caused by vibration of the object during a first period; acquiring measurement data of the physical quantity caused by vibration of the object during a second period different from the first period; generating a Lissajous figure based on a difference between the measurement data in the first period and the measurement data in the second period; to be executed by the computer. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 3 is a flowchart showing the procedure of the signal processing method according to the first embodiment. [Figure 2] FIG. 4 is a diagram showing a waveform of part of measurement data in a first period. [Figure 3] FIG. 10 is a diagram showing a waveform of part of measurement data in the (i+1)th period. [Figure 4] FIG. 10 is a diagram showing the waveform of the difference between the measurement data in the first period and the measurement data in the i-th period. [Figure 5] FIG. 2 is a diagram showing an example of the i-th Lissajous figure. [Figure 6] FIG. 10 is a diagram showing another example of the i-th Lissajous figure. [Figure 7] FIG. 1 is a diagram showing an example of the configuration of a signal processing device that executes a signal processing method according to a first embodiment. [Figure 8] FIG. 10 is a flowchart showing the procedure of a signal processing method according to a second embodiment. [Figure 9] FIG. 10 is a diagram showing an example of the configuration of a signal processing device that executes a signal processing method according to a second embodiment. [Figure 10] FIG. 10 is a flowchart showing the procedure of a signal processing method according to a third embodiment. [Figure 11] FIG. 10 is a diagram showing transition information including first to i-th Lissajous figures in time series. [Figure 12] FIG. 10 is a diagram showing transition information including the areas of the first to i-th Lissajous figures in time series. [Figure 13] FIG. 10 is a diagram showing an example of the configuration of a signal processing device that executes a signal processing method according to a third embodiment. [Figure 14] FIG. 10 is a flowchart showing the procedure of a signal processing method according to a fourth embodiment. [Figure 15] FIG. 10 is a diagram showing an example of a state diagnosis of an object. [Figure 16] FIG. 10 is a diagram showing an example of the configuration of a signal processing device that executes a signal processing method according to a fourth embodiment. [Figure 17] FIG. 1 is a diagram showing an example of the configuration of a signal processing system according to an embodiment of the present invention. [Figure 18] FIG. 2 is a schematic perspective view showing the configuration of a vacuum pump. [Figure 19] FIG. 2 is a schematic cross-sectional side view showing the internal structure of a vacuum pump. [Figure 20] FIG. 2 is a schematic cross-sectional plan view showing the internal structure of a vacuum pump. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that the embodiments described below do not unduly limit the content of the present invention as defined in the claims. Furthermore, not all of the configurations described below are necessarily essential components of the present invention.

[0011] 1. Signal processing method and signal processing device 1-1. First embodiment 1-1-1.Signal processing method 1 is a flowchart showing the steps of a signal processing method according to the first embodiment. The signal processing method according to the first embodiment is executed, for example, by a signal processing device 100 operating in accordance with a signal processing program. An example of the configuration of the signal processing device 100 that executes the signal processing method according to the first embodiment will be described later.

[0012] 1, first, in step S10, the signal processing device 100 acquires measurement data of physical quantities caused by vibration of an object during a first period. The measurement data is data based on signals output from a physical quantity sensor that detects physical quantities on multiple axes caused by vibration of the object. The measurement data may be time-series data of digital signals output from the physical quantity sensor, or time-series data of digital signals obtained by converting analog signals output from the physical quantity sensor by an analog front end.

[0013] The first period may be a period of any length, and may be, for example, a period during which the object is known to be in a normal state. The measurement data is, for example, time-series data of physical quantities on multiple axes detected by a physical quantity sensor. The physical quantity sensor may detect the physical quantity multiple times during the first period and output the measurement data for the multiple times, and the signal processing device 100 may acquire the measurement data for the multiple times. For example, if the first period is a one-day period and the physical quantity sensor detects the physical quantity six times every four hours, the signal processing device 100 may acquire the measurement data for the six times.

[0014] The multiple axes along which the physical quantity sensor detects the physical quantity may be, for example, two axes, three axes, or more than three axes. The multiple axes preferably intersect each other and are perpendicular to each other. The physical quantity sensor may be, for example, a sensor using a MEMS resonator or a sensor using a quartz resonator. MEMS is an abbreviation for Micro Electro Mechanical Systems. Furthermore, the physical quantity sensor may be built into a single device such as an IMU, or at least one of the multiple sensors that detect the physical quantity of each axis may be physically separated from the other sensors. IMU is an abbreviation for Inertial Measurement Unit.

[0015] The object is an object to be subjected to signal processing, and its type is not particularly limited, and may be, for example, various devices such as electric motors or motors having a rotating mechanism or a vibrating mechanism, structures such as bridges or buildings that vibrate due to external forces, or electrical circuits that generate periodic signals. The type of physical quantity generated by the vibration of the object is not particularly limited, and for example, the physical quantity may be acceleration, angular velocity, velocity, displacement, pressure, current, voltage, etc.

[0016] Next, in step S20, signal processing device 100 sets integer i to 1, and in step S30, acquires measurement data of physical quantities caused by vibration of the object in the (i+1)th time period. Because integer i is 1, in step S30, signal processing device 100 acquires second measurement data, which is measurement data of physical quantities caused by vibration of the object in a second time period.

[0017] The i-th period may be a period of any length, and the physical quantity sensor may detect the physical quantity multiple times during the i-th period and output the measurement data for the multiple times, and the signal processing device 100 may acquire the measurement data for the multiple times. For example, if the i-th period is a one-day period and the physical quantity sensor detects the physical quantity six times every four hours, the signal processing device 100 may acquire the measurement data for the six times. The physical quantity sensor that detects the physical quantity of the object in the first period and the physical quantity sensor that detects the physical quantity of the object in the i-th period are preferably the same, but may be different. In the latter case, it is sufficient that the two physical quantity sensors detect the same type of physical quantity, and it is preferable that the two physical quantity sensors have the same model number.

[0018] Next, in step S40, the signal processing device 100 generates an i-th Lissajous figure based on the difference between the measurement data for the first period acquired in step S10 and the measurement data for the (i+1)-th period acquired in step S30. Since the integer i is 1, the signal processing device 100 generates a first Lissajous figure in step S40 based on the difference between the measurement data for the first period and the measurement data for the second period. For example, if a physical quantity sensor detects physical quantities on the X-axis and Y-axis, and the measurement data includes time-series data of the physical quantity on the X-axis and time-series data of the physical quantity on the Y-axis, the signal processing device 100 may generate, as the i-th Lissajous figure, a Lissajous figure on a two-dimensional plane with the first axis as the X-axis and the second axis as the Y-axis. Furthermore, when a physical quantity sensor detects physical quantities on the X-axis, Y-axis, and Z-axis, and measurement data includes time series data of the physical quantity on the X-axis, time series data of the physical quantity on the Y-axis, and time series data of the physical quantity on the Z-axis, the signal processing device 100 may generate, as the ith Lissajous figure, a Lissajous figure in a three-dimensional space with the first axis as the X-axis, the second axis as the Y-axis, and the third axis as the Z-axis. In this case, the signal processing device 100 may generate at least one of a Lissajous figure on a two-dimensional plane with the first axis as the X-axis and the second axis as the Y-axis, a Lissajous figure on a two-dimensional plane with the first axis as the Y-axis and the second axis as the Z-axis, and a Lissajous figure on a two-dimensional plane with the first axis as the Z-axis and the second axis as the X-axis.

[0019] Furthermore, when the signal processing device 100 acquires multiple sets of measurement data in each of steps S10 and S30, it may generate multiple Lissajous figures based on the multiple sets of measurement data and average the multiple Lissajous figures to generate the ith Lissajous figure in step S40. For example, if the first period and the (i+1)th period are both one day and the physical quantity sensor detects the physical quantity six times every four hours, the signal processing device 100 may generate six Lissajous figures based on the six sets of measurement data and average the six Lissajous figures to generate the ith Lissajous figure.

[0020] Then, the signal processing device 100 increments the integer i by 1 in step S110 and repeats steps S30 and S40 until the signal processing in step S100 is completed.

[0021] Fig. 2 is a diagram showing the waveform of part of the measurement data in the first period acquired in step S10 of Fig. 1. Fig. 3 is a diagram showing the waveform of part of the measurement data in the (i+1)th period acquired in step S30 of Fig. 1. In Figs. 2 and 3, the solid line is the waveform of the velocity in the X-axis direction, the dashed line is the waveform of the velocity in the Y-axis direction, and the dashed line is the waveform of the velocity in the Z-axis direction.

[0022] Fig. 4 is a diagram showing the waveform of the difference between the measurement data in the first period shown in Fig. 2 and the measurement data in the i-th period shown in Fig. 3. In Fig. 4, the solid line is the waveform of the difference in velocity in the X-axis direction, the dashed line is the waveform of the difference in velocity in the Y-axis direction, and the dashed line is the waveform of the difference in velocity in the Z-axis direction.

[0023] Fig. 5 is a diagram showing an example of the ith Lissajous figure generated in step S40 of Fig. 1. The ith Lissajous figure shown in Fig. 5 is a three-dimensional Lissajous figure generated from the waveform shown in Fig. 4, and has the shape of an ellipsoid extending in the X-axis, Y-axis, and Z-axis directions with the origin as its center.

[0024] Fig. 6 is a diagram showing another example of the ith Lissajous figure generated in step S40 of Fig. 1. The ith Lissajous figure shown in Fig. 6 is a two-dimensional Lissajous figure generated from the waveform of the velocity difference in the X-axis direction and the waveform of the velocity difference in the Y-axis direction shown in Fig. 4, and has an elliptical shape centered at the origin and extending in the X-axis and Y-axis directions. The two-dimensional Lissajous figure shown in Fig. 6 corresponds to the three-dimensional Lissajous figure shown in Fig. 5 projected onto the XY plane.

[0025] A user can periodically monitor a Lissajous figure such as that shown in Figure 5 or 6 and diagnose the condition of the object from its size and shape. For example, the user can compare the major axis of the Lissajous figure with a predetermined threshold, and if the major axis of the Lissajous figure is larger than the threshold, diagnose that the condition of the object has changed or become abnormal with the passage of time from the first period to the i-th period.

[0026] 1-1-2.Signal processing device Fig. 7 is a diagram showing an example of the configuration of a signal processing device 100 that executes the signal processing method of the first embodiment. As shown in Fig. 7, the signal processing device 100 includes a physical quantity sensor 200, an analog front-end 210, a processing circuit 110, a memory circuit 120, an operation unit 130, a display unit 140, a sound output unit 150, and a communication unit 160. Note that the signal processing device 100 may be configured by omitting or changing some of the components shown in Fig. 7, or by adding other components. For example, the physical quantity sensor 200 and the analog front-end 210 do not have to be components of the signal processing device 100.

[0027] The physical quantity sensor 200 detects a physical quantity caused by vibration of an object and outputs a signal having a magnitude corresponding to the detected physical quantity. The output signal of the physical quantity sensor 200 is input to the analog front end 210.

[0028] The analog front end 210 performs amplification processing, A / D conversion processing, etc. on the output signal of the physical quantity sensor 200, and outputs a digital time-series signal.

[0029] The processing circuit 110 acquires, as measurement data, a digital time-series signal output from the physical quantity sensor 200 and output from the analog front-end 210, and performs signal processing. Specifically, the processing circuit 110 executes a signal processing program 121 stored in the memory circuit 120 and performs various calculation processes on the measurement data. In addition, the processing circuit 110 performs various processes in response to operation signals from the operation unit 130, a process of transmitting display signals for displaying various information on the display unit 140, a process of transmitting sound signals for generating various sounds to the sound output unit 150, a process of controlling the communication unit 160 for data communication with an external device (not shown), and the like. The processing circuit 110 is realized by, for example, a CPU or a DSP. CPU is an abbreviation for Central Processing Unit, and DSP is an abbreviation for Digital Signal Processor.

[0030] The processing circuitry 110 executes the signal processing program 121 to function as a measurement data acquisition circuitry 111 and a Lissajous figure generation circuitry 112. That is, the signal processing device 100 includes the measurement data acquisition circuitry 111 and the Lissajous figure generation circuitry 112.

[0031] The measurement data acquisition circuit 111 acquires measurement data of physical quantities caused by vibration of the object in a first time period. The measurement data acquisition circuit 111 also acquires measurement data of physical quantities caused by vibration of the object in an (i+1)th time period. That is, the measurement data acquisition circuit 111 executes steps S10 and S30 in FIG. 1 . The measurement data for the i-th time period acquired by the measurement data acquisition circuit 111 is stored in the memory circuit 120.

[0032] The Lissajous figure generation circuit 112 generates an ith Lissajous figure based on the difference between the measurement data for the first period acquired by the measurement data acquisition circuit 111 and the measurement data for the (i+1)th period acquired by the measurement data acquisition circuit 111. That is, the Lissajous figure generation circuit 112 executes step S40 in Fig. 1. The ith Lissajous figure generated by the Lissajous figure generation circuit 112 is stored in the memory circuit 120.

[0033] In this way, the signal processing program 121 is a program that causes the signal processing device 100, which is a computer, to execute each procedure of the flowchart shown in FIG.

[0034] The storage circuitry 120 has a ROM and a RAM (not shown). ROM is an abbreviation for Read Only Memory, and RAM is an abbreviation for Random Access Memory. The ROM stores various programs such as the signal processing program 121 and predetermined data, and the RAM stores data generated by the processing circuitry 110. The RAM is also used as a working area for the processing circuitry 110, and stores programs and data read from the ROM, data input from the operation unit 130, and data temporarily generated by the processing circuitry 110.

[0035] The operation unit 130 is an input device configured with operation keys, button switches, etc., and outputs an operation signal to the processing circuit 110 in response to an operation by a user.

[0036] The display unit 140 is a display device configured by an LCD or the like, and displays various information based on a display signal output from the processing circuit 110. LCD is an abbreviation for Liquid Crystal Display. The display unit 140 may be provided with a touch panel that functions as the operation unit 130. For example, the display unit 140 displays the first to Nth Lissajous figures and the dissimilarity degrees D1 to D2 based on the display signal output from the processing circuit 110. N-1 A screen including at least a part of the above may be displayed.

[0037] The sound output unit 150 is configured with a speaker or the like, and generates various sounds based on the sound signal output from the processing circuit 110. For example, the sound output unit 150 may generate sounds indicating the start or end of signal processing based on the sound signal output from the processing circuit 110.

[0038] The communication unit 160 performs various controls to establish data communication between the processing circuit 110 and an external device. For example, the communication unit 160 may transmit information including the ith Lissajous figure to the external device, and the external device may display at least a part of the received information on a display unit (not shown).

[0039] At least a portion of the measurement data acquisition circuit 111 and the Lissajous figure generation circuit 112 may be implemented by dedicated hardware. The signal processing device 100 may be a single device or may be configured by multiple devices. For example, the physical quantity sensor 200 and the analog front-end 210 may be included in a first device, and the processing circuit 110, the memory circuit 120, the operation unit 130, the display unit 140, the sound output unit 150, and the communication unit 160 may be included in a second device separate from the first device. Alternatively, for example, the processing circuit 110 and the memory circuit 120 may be implemented by a device such as a cloud server, which may generate information about the ith Lissajous figure and transmit the generated information to a terminal including the operation unit 130, the display unit 140, the sound output unit 150, and the communication unit 160 via a communication line.

[0040] 1-1-3.Effects In the signal processing method of the first embodiment described above, if the vibration state of the object changes little between the first period and the (i+1)th period, there is little difference between the measurement data of the first period and the measurement data of the (i+1)th period, and the i-th Lissajous figure will have a shape close to a point. On the other hand, if the vibration state of the object changes between the first period and the (i+1)th period, the change in state will be reflected in the size and shape of the i-th Lissajous figure. Therefore, according to the signal processing method of the first embodiment, the signal processing device 100 can provide the i-th Lissajous figure as an indicator that allows the user to diagnose the presence or absence of an abnormality even when an unexpected abnormality occurs in the vibration state of the object. Furthermore, the signal processing device 100 does not need to store Lissajous figures corresponding to expected abnormal modes in advance. Therefore, the user can easily diagnose the vibration state of the object based on the size and shape of the i-th Lissajous figure without requiring any special preparation or knowledge.

[0041] 1-2. Second embodiment In the following, in the second embodiment, the same components as those in the first embodiment are given the same reference numerals, and explanations that overlap with those in the first embodiment are omitted or simplified, and differences from the first embodiment are mainly described.

[0042] 8 is a flowchart showing the procedure of the signal processing method of the second embodiment. The signal processing method of the second embodiment is executed, for example, by the signal processing device 100 operating in accordance with a signal processing program. An example of the configuration of the signal processing device 100 that executes the signal processing method of the second embodiment will be described later.

[0043] As shown in FIG. 8, first, the signal processing device 100 executes steps S10 to S30, similarly to the first embodiment.

[0044] Next, in step S50, the signal processing device 100 calculates the area of ​​the ith Lissajous figure generated in step S40. Note that the ith Lissajous figure is a two-dimensional Lissajous figure.

[0045] Then, the signal processing device 100 increments the integer i by 1 in step S110 and repeats steps S30 to S50 until the signal processing in step S100 is completed.

[0046] 9 is a diagram showing an example of the configuration of a signal processing device 100 that executes the signal processing method of the second embodiment. As shown in FIG. 9, the signal processing device 100 includes a physical quantity sensor 200, an analog front-end 210, a processing circuit 110, a memory circuit 120, an operation unit 130, a display unit 140, a sound output unit 150, and a communication unit 160. Note that the signal processing device 100 may be configured by omitting or changing some of the components shown in FIG. 9 or by adding other components. For example, the physical quantity sensor 200 and the analog front-end 210 do not have to be components of the signal processing device 100.

[0047] The configurations and functions of the physical quantity sensor 200, analog front end 210, memory circuit 120, operation unit 130, display unit 140, sound output unit 150, and communication unit 160 are the same as those in the first embodiment, and therefore will not be described again.

[0048] The processing circuitry 110 executes a signal processing program 121 stored in the memory circuitry 120, thereby functioning as a measurement data acquisition circuit 111, a Lissajous figure generation circuit 112, and an area calculation circuit 113. That is, the signal processing device 100 includes the measurement data acquisition circuit 111, the Lissajous figure generation circuit 112, and the area calculation circuit 113.

[0049] The measurement data acquisition circuit 111 executes steps S10 and S30 in Fig. 8. The Lissajous figure generation circuit 112 executes step S40 in Fig. 8. The functions of the measurement data acquisition circuit 111 and the Lissajous figure generation circuit 112 are the same as in the first embodiment, and therefore description thereof will be omitted.

[0050] The area calculation circuit 113 calculates the area of ​​the ith Lissajous figure generated by the Lissajous figure generation circuit 112. That is, the area calculation circuit 113 executes step S50 in Fig. 8. Information about the area of ​​the ith Lissajous figure calculated by the area calculation circuit 113 is stored in the storage circuit 120.

[0051] The display unit 140 may display a screen including the i-th Lissajous figure and at least part of the information about the area of ​​the i-th Lissajous figure, based on a display signal output from the processing circuitry 110.

[0052] The communication unit 160 may transmit information including at least part of the information on the i-th Lissajous figure and the area of ​​the i-th Lissajous figure to an external device, and the external device may display at least part of the received information on a display unit (not shown).

[0053] At least a part of the measurement data acquisition circuit 111, the Lissajous figure generation circuit 112, and the area calculation circuit 113 may be realized by dedicated hardware.

[0054] Other configurations of the signal processing device 100 in the second embodiment are the same as those in the first embodiment, and therefore description thereof will be omitted.

[0055] The signal processing method of the second embodiment described above provides the same effects as the signal processing method of the first embodiment. Furthermore, according to the signal processing method of the second embodiment, the area of ​​the ith Lissajous figure increases as the change in the vibration state of the object between the first period and the (i+1)th period increases, and therefore the signal processing device 100 can provide information on the area of ​​the ith Lissajous figure as a useful index for diagnosing the vibration state of the object.

[0056] 1-3. Third embodiment Hereinafter, for the third embodiment, components similar to those in the first or second embodiment will be given the same symbols, and explanations that overlap with those in the first or second embodiment will be omitted or simplified, and the following will mainly describe the differences from the first and second embodiments.

[0057] 10 is a flowchart showing the procedure of the signal processing method of the third embodiment. The signal processing method of the third embodiment is executed, for example, by the signal processing device 100 operating in accordance with a signal processing program. An example of the configuration of the signal processing device 100 that executes the signal processing method of the third embodiment will be described later.

[0058] As shown in FIG. 10, first, the signal processing device 100 executes steps S10 to S50, similarly to the second embodiment.

[0059] Next, in step S60, the signal processing device 100 generates transition information related to the Lissajous figure. For example, as shown in FIG. 11, the signal processing device 100 may generate transition information including the first to i-th Lissajous figure generated in step S40 in a time series. The user can grasp changes in the area and shape of the Lissajous figure using the transition information of the Lissajous figure shown in FIG. 11 and diagnose the condition of the object. Furthermore, as shown in FIG. 12, the signal processing device 100 may generate transition information including the first to i-th Lissajous figure areas calculated in step S50 in a time series. In the example of FIG. 12, the area of ​​the Lissajous figure gradually increases from day 0 to about day 10, indicating that the object is in an "initial progression" state. From about day 10 to about day 19, the area of ​​the Lissajous figure remains almost unchanged, indicating that the object is in a "retention" state. On day 20, the area of ​​the Lissajous figure increases rapidly, and from day 20 onwards, the object is in a "terminal progression" state. The user can determine from the graph of transition information shown in FIG. 12 that an abnormality occurred in the object on the 20th day.

[0060] Then, the signal processing device 100 increments the integer i by 1 in step S110 and repeats steps S30 to S60 until the signal processing in step S100 is completed.

[0061] Fig. 13 is a diagram showing an example of the configuration of a signal processing device 100 that executes the signal processing method of the third embodiment. As shown in Fig. 13, the signal processing device 100 includes a physical quantity sensor 200, an analog front-end 210, a processing circuit 110, a memory circuit 120, an operation unit 130, a display unit 140, a sound output unit 150, and a communication unit 160. Note that the signal processing device 100 may be configured such that some of the components shown in Fig. 13 are omitted or modified, or other components are added. For example, the physical quantity sensor 200 and the analog front-end 210 do not have to be components of the signal processing device 100.

[0062] The configurations and functions of the physical quantity sensor 200, analog front end 210, memory circuit 120, operation unit 130, display unit 140, sound output unit 150, and communication unit 160 are the same as those of the first or second embodiment, and therefore will not be described again.

[0063] The processing circuitry 110 executes a signal processing program 121 stored in the memory circuitry 120, thereby functioning as a measurement data acquisition circuit 111, a Lissajous figure generation circuit 112, an area calculation circuit 113, and a transition information generation circuit 114. That is, the signal processing device 100 includes the measurement data acquisition circuit 111, the Lissajous figure generation circuit 112, the area calculation circuit 113, and the transition information generation circuit 114.

[0064] The measurement data acquisition circuit 111 executes steps S10 and S30 in Fig. 10. The Lissajous figure generation circuit 112 executes step S40 in Fig. 10. The area calculation circuit 113 executes step S50 in Fig. 10. The functions of the measurement data acquisition circuit 111 and the Lissajous figure generation circuit 112 are the same as those in the first or second embodiment, and therefore their description will be omitted. Furthermore, the function of the area calculation circuit 113 is the same as that in the second embodiment, and therefore its description will be omitted.

[0065] The transition information generation circuit 114 generates transition information related to Lissajous figures. For example, the transition information generation circuit 114 may generate transition information including, in time series, the first to i-th Lissajous figures generated by the Lissajous figure generation circuit 112. The transition information generation circuit 114 may also generate transition information including, in time series, the areas of the first to i-th Lissajous figures calculated by the area calculation circuit 113. In this way, the transition information generation circuit 114 executes step S60 in FIG. 10. The transition information generated by the transition information generation circuit 114 is stored in the storage circuit 120.

[0066] The display unit 140 may display a screen including the i-th Lissajous figure, information about the area of ​​the i-th Lissajous figure, and at least a part of the transition information, based on a display signal output from the processing circuitry 110.

[0067] The communication unit 160 transmits information including the i-th Lissajous figure, information about the area of ​​the i-th Lissajous figure, and at least a portion of the transition information to an external device, and the external device may display at least a portion of the received information on a display unit not shown.

[0068] At least some of the measurement data acquisition circuit 111, the Lissajous figure generation circuit 112, the area calculation circuit 113, and the transition information generation circuit 114 may be realized by dedicated hardware.

[0069] The other configurations of the signal processing device 100 in the third embodiment are the same as those in the first or second embodiment, and therefore the description thereof will be omitted.

[0070] The signal processing method of the third embodiment described above provides the same effects as the signal processing method of the first or second embodiment. Furthermore, according to the signal processing method of the third embodiment, the signal processing device 100 generates transition information related to the Lissajous figure, so that the user can grasp the timing at which the vibration state of the object changes based on the transition information.

[0071] 1-4. Fourth embodiment Hereinafter, for the fourth embodiment, components similar to those of any of the first to third embodiments will be given the same symbols, and explanations that overlap with those of any of the first to third embodiments will be omitted or simplified, and the following will mainly describe the differences from any of the first to third embodiments.

[0072] 14 is a flowchart showing the procedure of the signal processing method of the fourth embodiment. The signal processing method of the fourth embodiment is executed, for example, by the signal processing device 100 operating in accordance with a signal processing program. An example of the configuration of the signal processing device 100 that executes the signal processing method of the fourth embodiment will be described later.

[0073] As shown in FIG. 14, first, the signal processing device 100 executes steps S10 to S60, similarly to the third embodiment.

[0074] Next, in step S70, the signal processing device 100 diagnoses the state of the object based on the i-th Lissajous figure generated in step S40. For example, as shown in FIG. 15, the signal processing device 100 may diagnose the state of the object based on the area or shape of the Lissajous figure. For example, the signal processing device 100 may diagnose the state of the object as abnormal if the area of ​​the Lissajous figure exceeds a predetermined threshold. Furthermore, for example, the signal processing device 100 may calculate the distance between each point of the Lissajous figure and the origin, and diagnose the state of the object as abnormal if the distance between any point and the origin exceeds a predetermined threshold.

[0075] Furthermore, the signal processing device 100 may diagnose whether the object is in a normal state or an abnormal state, and if the object is in an abnormal state, which abnormal mode the object is in, based on the area and shape of the Lissajous figure. For example, as shown in the upper part of FIG. 15, when the Lissajous figure is in a shape close to a point, the signal processing device 100 can diagnose that the object is in a normal state. On the other hand, as shown in the middle part of FIG. 15, when the area of ​​the Lissajous figure is larger than a threshold and the shape of the Lissajous figure is longer in the X-axis direction than in the Y-axis direction, the signal processing device 100 can diagnose that the object is in an abnormal state of abnormal mode A, in which a part causing vibration in the X-axis direction is deteriorated. Furthermore, as shown in the lower part of FIG. 15, when the area of ​​the Lissajous figure is larger than a threshold and the shape of the Lissajous figure is longer in the Y-axis direction than in the X-axis direction, the signal processing device 100 can diagnose that the object is in an abnormal state of abnormal mode B, in which a part causing vibration in the Y-axis direction is deteriorated.

[0076] Then, the signal processing device 100 increments the integer i by 1 in step S110 and repeats steps S30 to S70 until the signal processing in step S100 is completed.

[0077] Fig. 16 is a diagram showing an example of the configuration of a signal processing device 100 that executes the signal processing method of the fourth embodiment. As shown in Fig. 16, the signal processing device 100 includes a physical quantity sensor 200, an analog front-end 210, a processing circuit 110, a memory circuit 120, an operation unit 130, a display unit 140, a sound output unit 150, and a communication unit 160. Note that the signal processing device 100 may be configured such that some of the components shown in Fig. 16 are omitted or modified, or other components are added. For example, the physical quantity sensor 200 and the analog front-end 210 do not have to be components of the signal processing device 100.

[0078] The configurations and functions of the physical quantity sensor 200, analog front end 210, memory circuit 120, operation unit 130, display unit 140, sound output unit 150, and communication unit 160 are the same as those of any of the first to third embodiments, and therefore will not be described again.

[0079] The processing circuitry 110 executes a signal processing program 121 stored in the memory circuitry 120, thereby functioning as a measurement data acquisition circuit 111, a Lissajous figure generation circuit 112, an area calculation circuit 113, a transition information generation circuit 114, and a condition diagnosis circuit 115. That is, the signal processing device 100 includes the measurement data acquisition circuit 111, the Lissajous figure generation circuit 112, the area calculation circuit 113, the transition information generation circuit 114, and the condition diagnosis circuit 115.

[0080] The measurement data acquisition circuit 111 executes steps S10 and S30 in Fig. 14. The Lissajous figure generation circuit 112 executes step S40 in Fig. 14. The area calculation circuit 113 executes step S50 in Fig. 14. The transition information generation circuit 114 executes step S60 in Fig. 14. The functions of the measurement data acquisition circuit 111 and the Lissajous figure generation circuit 112 are the same as those in any of the first to third embodiments, the function of the area calculation circuit 113 is the same as that in the second or third embodiment, and the function of the transition information generation circuit 114 is the same as that in the third embodiment, so their description will be omitted.

[0081] The condition diagnosis circuit 115 diagnoses the condition of the object based on the ith Lissajous figure generated by the Lissajous figure generation circuit 112. For example, the condition diagnosis circuit 115 may diagnose the condition of the object based on the area or shape of the ith Lissajous figure. In this manner, the condition diagnosis circuit 115 executes step S70 in FIG. 14. The diagnosis result by the condition diagnosis circuit 115 is stored in the memory circuit 120.

[0082] The display unit 140 may display a screen including the i-th Lissajous figure, information on the area of ​​the i-th Lissajous figure, transition information, and at least a portion of the diagnostic results of the condition of the object, based on the display signal output from the processing circuit 110.

[0083] The communication unit 160 transmits information including the ith Lissajous figure, the ith Lissajous figure, information on the area of ​​the ith Lissajous figure, transition information, and at least a portion of the diagnostic results of the condition of the object to an external device, and the external device may display at least a portion of the received information on a display unit not shown.

[0084] At least some of the measurement data acquisition circuit 111, the Lissajous figure generation circuit 112, the area calculation circuit 113, the transition information generation circuit 114, and the condition diagnosis circuit 115 may be realized by dedicated hardware.

[0085] The other configurations of the signal processing device 100 in the fourth embodiment are the same as those in any of the first to third embodiments, and therefore the description thereof will be omitted.

[0086] The signal processing method of the fourth embodiment described above provides the same effects as the signal processing methods of the first to third embodiments. Furthermore, according to the signal processing method of the fourth embodiment, a change in the vibration state of the object between the first period and the (i+1)th period is reflected in the size and shape of the i-th Lissajous figure, so the signal processing device 100 can correctly diagnose the state of the object based on the i-th Lissajous figure. Furthermore, since the signal processing device 100 objectively diagnoses the state of the object, the effort required for diagnosis by the user and the variability in the diagnosis results are reduced.

[0087] 2.Signal Processing System Hereinafter, for the signal processing system of this embodiment, components similar to those described in any of the above embodiments will be given the same symbols, and explanations that overlap with any of the above embodiments will be omitted or simplified, with the main focus being on the differences from any of the above embodiments.

[0088] 17 is a diagram showing an example of the configuration of a signal processing system of this embodiment. As shown in Fig. 17, the signal processing system 10 of this embodiment includes a physical quantity sensor 200, an analog front-end 210, a signal processing device 100, and a display device 220.

[0089] The object 1 includes a movable body 2 and a housing 3 that houses the movable body 2. The physical quantity sensor 200 is attached to the housing 3, detects a physical quantity caused by vibration of the object 1, and outputs a signal having a magnitude corresponding to the detected physical quantity. The output signal of the physical quantity sensor 200 is input to an analog front end 210.

[0090] The analog front end 210 performs amplification processing, A / D conversion processing, etc. on the output signal of the physical quantity sensor 200, and outputs a digital time-series signal.

[0091] The signal processing device 100 acquires, as measurement data for the first period, a digital time-series signal output from the physical quantity sensor 200 and output from the analog front-end 210 during a first period. Furthermore, the signal processing device 100 acquires, as measurement data for the (i+1)-th period, a digital time-series signal output from the physical quantity sensor 200 and output from the analog front-end 210 during an (i+1)-th period. The signal processing device 100 then generates an i-th Lissajous figure based on the difference between the measurement data for the first period and the measurement data for the (i+1)-th period. Furthermore, the signal processing device 100 may calculate the area of ​​the i-th Lissajous figure, or may generate transition information including the first to i-th Lissajous figures and their areas in a time series. Furthermore, the signal processing device 100 may diagnose the state of an object based on the i-th Lissajous figure. Then, the signal processing device 100 causes the display device 220 to display at least a part of various information such as the ith Lissajous figure, information on the area of ​​the ith Lissajous figure, transition information, and the diagnosis result of the state of the object. The display device 220 may be a device separate from the signal processing device 100, or may be a display unit included in the signal processing device 100. Note that when the physical quantity sensor 200 outputs a digital time-series signal, the signal processing device 100 only needs to acquire the digital time-series signal, and therefore the analog front end 210 may not be required. As the signal processing device 100, for example, any of the signal processing devices 100 of the first to fourth embodiments described above can be applied.

[0092] FIG. 18 shows a vacuum pump 1a, which is an example of the target object 1. As shown in FIG. 18, the vacuum pump 1a is installed on a base 20. The cross section of the vacuum pump 1a is a columnar shape with a substantially oval shape. The longitudinal direction of the vacuum pump 1a is defined as the X direction. The long axis direction of the oval shape is defined as the Y direction, and the short axis direction of the oval shape is defined as the Z direction.

[0093] The vacuum pump 1a includes a housing 3. The housing 3 includes a motor case 4, a connection portion 5, a pump case 6, and a gear case 7, which are arranged from the -X direction side toward the +X direction side. The housing 3 includes a first side wall 8 serving as a bearing casing between the connection portion 5 and the pump case 6. The housing 3 includes a second side wall 9 between the pump case 6 and the gear case 7.

[0094] An intake pipe 11 is connected to the surface of the pump case 6 on the +Z direction side, and an exhaust pipe 12 is connected to the surface of the pump case 6 on the −Z direction side.

[0095] The connecting part 5 has a first leg 13 and a second leg on the base 20 side. The first leg 13 is arranged on the -Y direction side, and the second leg is arranged on the +Y direction side. The gear case 7 has a third leg 14 and a fourth leg on the base 20 side. The third leg 14 is arranged on the -Y direction side, and the fourth leg is arranged on the +Y direction side. The first leg 13 to the fourth leg are fastened to the base 20 by a first bolt 15.

[0096] A physical quantity sensor 200 is attached to the housing 3. The physical quantity sensor 200 is attached to, for example, the connection portion 5. For example, the physical quantity sensor 200 may be a three-axis acceleration sensor that detects acceleration in the X-axis direction, acceleration in the Y-axis direction, and acceleration in the Z-axis direction. Furthermore, for example, the physical quantity sensor 200 may be a three-axis velocity sensor that detects velocity in the X-axis direction, velocity in the Y-axis direction, and velocity in the Z-axis direction.

[0097] The internal structure of vacuum pump 1a will be described using Figures 19 and 20. Figure 19 is a view from the -Y direction. Figure 20 is a view from the +Z direction. The first leg 13 to the fourth leg 14 are omitted from the figure. Vacuum pump 1a includes pump rotors 18 as two movable bodies 2 that transfer gas, and two motors 19 that rotate the two pump rotors 18. Housing 3 houses pump rotors 18.

[0098] The two pump rotors 18 have two rotating shafts 21. The two rotating shafts 21 are rotatably supported by first and second bearings 22 and 23, respectively. Two motors 19 are connected to one end of each rotating shaft 21. The motors 19 are configured to rotate the two pump rotors 18 in synchronous directions opposite to each other. Two timing gears 24 are fixed to the other end of the rotating shafts 21. These timing gears 24 are provided to ensure synchronous rotation of the two pump rotors 18 in the event that the two motors 19 lose synchronous rotation.

[0099] The pump case 6 is sandwiched between a first side wall 8 and a second side wall 9. The pump rotor 18 is disposed in a pump chamber 25 defined by the pump case 6, the first side wall 8, and the second side wall 9.

[0100] The first side wall 8 supports a first bearing 22 on the intake pipe 11 side. The first bearing 22 is disposed within the connecting portion 5. The motor 19 is disposed within a motor case 4 fixed to the connecting portion 5. A second bearing 23 on the exhaust pipe 12 side is fixed to the second side wall 9. The timing gear 24 and the second bearing 23 are disposed within the gear case 7. The first bearing 22 and the second bearing 23 vibrate due to the rotation of the pump rotor 18. The vibrations of the first bearing 22 and the second bearing 23 are transmitted to the housing 3 of the connecting portion 5 etc. via the first side wall 8 and the second side wall 9. The physical quantity sensor 200 detects the vibrations transmitted to the housing 3.

[0101] According to the signal processing system 10 of this embodiment, the user can monitor the condition of the object 1 based on the information displayed on the display device 220, and accurately diagnose whether the condition of the object 1 is normal or abnormal, and in which abnormal mode the object 1 is in, etc.

[0102] The present invention is not limited to this embodiment, and various modifications are possible within the scope of the present invention. For example, measurement data of physical quantities caused by vibration of a new (normal) vacuum pump 1a may be obtained as the object 1 in step S10, and measurement data of physical quantities caused by vibration of another vacuum pump of the same model as the vacuum pump 1a may be obtained as the object 1 in step S30. In this way, by using a normal product as a reference, a Lissajous figure can also be generated in step S40.

[0103] The above-described embodiment and modifications are merely examples, and the present invention is not limited to these. For example, the embodiments and modifications can be combined as appropriate.

[0104] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects. The present invention also includes configurations that replace non-essential parts of the configurations described in the embodiments. The present invention also includes configurations that achieve the same effects or purposes as the configurations described in the embodiments. The present invention also includes configurations that add publicly known technology to the configurations described in the embodiments.

[0105] The following can be derived from the above-described embodiment and modifications.

[0106] One aspect of the signal processing method includes: acquiring measurement data of a physical quantity caused by vibration of the object during a first period; acquiring measurement data of the physical quantity caused by vibration of the object during a second period different from the first period; generating a Lissajous figure based on a difference between the measurement data in the first period and the measurement data in the second period; Includes.

[0107] In this signal processing method, if the vibration state of the object changes little between the first and second periods, there is little difference between the measurement data in the first and second periods, and the Lissajous figure will have a shape close to a point. On the other hand, if the vibration state of the object changes between the first and second periods, the change in state will appear as a Lissajous figure. Therefore, this signal processing method can provide an indicator that allows the user to diagnose the presence or absence of an abnormality even when an unexpected abnormality occurs in the vibration state of the object. Furthermore, the user can easily diagnose the vibration state of the object without requiring any special preparation or knowledge.

[0108] In one aspect of the signal processing method, The Lissajous figure may be a three-dimensional Lissajous figure.

[0109] In one aspect of the signal processing method, The Lissajous figure is a two-dimensional Lissajous figure, The method may include a step of calculating the area of ​​the Lissajous figure.

[0110] In this signal processing method, the greater the change in the vibration state of the object between the first period and the second period, the larger the area of ​​the Lissajous figure, and therefore, this signal processing method can provide a useful indicator for diagnosing the vibration state of the object.

[0111] One aspect of the signal processing method is The method may further include generating transition information regarding the Lissajous figure.

[0112] According to this signal processing method, the user can grasp the timing at which the vibration state of the object changes based on the transition information regarding the Lissajous figure.

[0113] One aspect of the signal processing method is The method may further include a step of diagnosing a condition of the object based on the Lissajous figure.

[0114] According to this signal processing method, the change in the vibration state of the object between the first period and the second period is reflected in the size and shape of the Lissajous figure, so that the state of the object can be correctly diagnosed.

[0115] One aspect of the signal processing device includes: a measurement data acquisition circuit that acquires measurement data of a physical quantity caused by vibration of an object during a first period and measurement data of the physical quantity caused by vibration of the object during a second period different from the first period; a Lissajous figure generating circuit that generates a Lissajous figure based on a difference between the measurement data in the first period and the measurement data in the second period; Equipped with.

[0116] In this signal processing device, if the vibration state of the object changes little between the first and second periods, there is little difference between the measurement data in the first and second periods, and the Lissajous figure will have a shape close to a point. On the other hand, if the vibration state of the object changes between the first and second periods, the change in state will appear as a Lissajous figure. Therefore, this signal processing device can provide an indicator that allows the user to diagnose the presence or absence of an abnormality even when an unexpected abnormality occurs in the vibration state of the object. Furthermore, the user can easily diagnose the vibration state of the object without requiring any special preparation or knowledge.

[0117] One aspect of the signal processing system comprises: An aspect of the signal processing device; a physical quantity sensor that detects the physical quantity; Equipped with.

[0118] One aspect of the signal processing program is acquiring measurement data of a physical quantity caused by vibration of the object during a first period; acquiring measurement data of the physical quantity caused by vibration of the object during a second period different from the first period; generating a Lissajous figure based on a difference between the measurement data in the first period and the measurement data in the second period; to be executed by the computer.

[0119] In this signal processing program, if the vibration state of the object changes little between the first and second periods, there will be little difference between the measurement data in the first and second periods, and the Lissajous figure will have a shape close to a point. On the other hand, if the vibration state of the object changes between the first and second periods, the change in state will appear as a Lissajous figure. Therefore, this signal processing program can provide an indicator that allows the user to diagnose the presence or absence of an abnormality even when an unexpected abnormality occurs in the vibration state of the object. Furthermore, the user can easily diagnose the vibration state of the object without requiring any special preparation or knowledge. [Explanation of symbols]

[0120] 1...object, 1a...vacuum pump, 2...moving body, 3...housing, 4...motor case, 5...connection part, 6...pump case, 7...gear case, 8...first side wall, 9...second side wall, 10...signal processing system, 11...intake pipe, 12...exhaust pipe, 13...first leg, 14...third leg, 15...first bolt, 18...pump rotor, 19...motor, 20...base, 21...rotating shaft, 22...first bearing, 23...second bearing, 24...timing gear, 2 5...pump chamber, 100...signal processing device, 110...processing circuit, 111...measurement data acquisition circuit, 112...lissajous figure generation circuit, 113...area calculation circuit, 114...transition information generation circuit, 115...condition diagnosis circuit, 120...memory circuit, 121...signal processing program, 130...operation unit, 140...display unit, 150...sound output unit, 160...communication unit, 200...physical quantity sensor, 210...analog front end, 220...display device

Claims

1. acquiring measurement data of a physical quantity caused by vibration of the object during a first period; acquiring measurement data of the physical quantity caused by vibration of the object during a second period different from the first period; generating a Lissajous figure based on a difference between the measurement data in the first period and the measurement data in the second period; A signal processing method comprising:

2. In claim 1, A signal processing method, wherein the Lissajous figure is a three-dimensional Lissajous figure.

3. In claim 1, the Lissajous figure is a two-dimensional Lissajous figure, A signal processing method comprising the step of calculating the area of ​​the Lissajous figure.

4. In claim 1, A signal processing method comprising the step of generating transition information relating to the Lissajous figure.

5. In claim 1, A signal processing method comprising a step of diagnosing a state of the object based on the Lissajous figure.

6. a measurement data acquisition circuit that acquires measurement data of a physical quantity caused by vibration of an object during a first period and measurement data of the physical quantity caused by vibration of the object during a second period different from the first period; a Lissajous figure generating circuit that generates a Lissajous figure based on a difference between the measurement data in the first period and the measurement data in the second period; A signal processing device comprising:

7. A signal processing device according to claim 6; a physical quantity sensor that detects the physical quantity; A signal processing system comprising:

8. acquiring measurement data of a physical quantity caused by vibration of the object during a first period; acquiring measurement data of the physical quantity caused by vibration of the object during a second period different from the first period; generating a Lissajous figure based on a difference between the measurement data in the first period and the measurement data in the second period; A signal processing program that causes a computer to execute the following.

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