Detection device, time synchronization method, computer-readable storage medium, and detection system

Abstract

The invention relates to a detection apparatus, a time synchronization method, a computer-readable storage medium, and a detection system. A detection device (10) according to an embodiment includes: an internal clock; an excitation unit (11) that generates vibration each time a time-related condition is satisfied; a vibration pick-up unit (12) that detects vibrations; a measurement unit (142) that measures the time from the time when the vibration is generated by the vibration excitation unit (11) to the time when the vibration is detected by the vibration pickup unit (12); a determination unit (141) that determines a mode on the basis of whether or not the time measured by the measurement unit (142) is longer than a predetermined interval time; and a correction unit (143) that determines whether or not to correct the deviation of the internal clock on the basis of the reference time when the mode is determined to be the specific mode, and corrects the internal clock when the mode is determined to be corrected.

Description

Technical Field

[0001] The invention relates to a detection device, a time synchronization method, a computer-readable storage medium and a detection system. Background Art

[0002] There is known a method of identifying the position of the source of vibration by comparing sensor values ​​related to vibration measured by a plurality of sensors based on the time of measurement.

[0003] Furthermore, vibrations contain sound.

[0004] Patent Document 1 describes a method in which two sensors mutually output vibrations and each sensor measures the vibration outputted by the other sensor, thereby synchronizing the time of each other's internal clocks.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-96651 Summary of the invention

[0006] However, the conventional technology has a problem in that time synchronization that takes into account the positional relationship among a plurality of sensors may not be performed.

[0007] For example, a plurality of sensors may be configured differently depending on whether they are installed before or after installation. In this case, it is conceivable that the positional relationship between the sensors is different depending on whether they are installed before or after installation. On the other hand, in the prior art, the positional relationship between the sensors caused by whether they are installed before or after installation is not considered.

[0008] For example, even if the time difference between sensors is detected using the method described in Patent Document 1, it is difficult to determine whether the difference is caused by a difference in the internal clock itself or by a change in the transmission time due to a change in the positional relationship.

[0009] When the internal clock deviates, the internal clock needs to be corrected for time synchronization. On the other hand, when the time deviation is detected due to a change in the positional relationship between sensors, the internal clock does not need to be corrected.

[0010] One aspect of the present invention is to perform time synchronization taking into account the positional relationship between a plurality of sensors.

[0011] The detection device involved in one aspect is characterized in that the detection device comprises: an internal clock; an excitation unit, which generates vibrations whenever a time-related condition is satisfied; a vibration pickup unit, which detects the vibrations; a measuring unit, which measures the time from the time when the excitation unit generates the vibrations to the time when the vibration pickup unit detects the vibrations; a determination unit, which determines a mode based on whether the time measured by the measuring unit is longer than a prescribed interval time; and a correction unit, which determines whether to correct the deviation of the internal clock based on a reference time when it is determined to be a specific mode, and corrects the internal clock when it is determined to be a correction.

[0012] One aspect of the time synchronization method is a time synchronization method performed by a detection device, the detection device comprising: an internal clock; an excitation unit, which generates vibrations whenever a time-related condition is met; and a vibration pickup unit, which detects vibrations. The time synchronization method is characterized in that it includes the following steps: a measurement step, which measures the time from the time the excitation unit generates vibrations to the time the vibration pickup unit detects the vibrations; a determination step, which determines a mode based on whether the time measured by the measurement step is longer than a specified interval time; and a correction step, which determines whether to correct the deviation of the internal clock based on a reference time when it is determined to be a specific mode, and corrects the internal clock when it is determined to be a correction.

[0013] One aspect involves a computer-readable recording medium that records a time synchronization program, characterized in that the time synchronization program causes a detection device to execute a measurement step, a judgment step, and a correction step, the detection device comprising: an internal clock; an excitation unit that generates vibrations whenever a time-related condition is met; and a vibration pickup unit that detects vibrations, wherein in the measurement step, the time from the time the excitation unit generates vibrations to the time the vibration pickup unit detects the vibrations is measured, and in the judgment step, a mode is determined based on whether the time measured by the measurement step is longer than a specified interval time, and in the correction step, if it is determined to be a specific mode, it is determined based on a reference time whether the deviation of the internal clock is to be corrected, and if it is determined to be a correction, the internal clock is corrected.

[0014] A detection system according to one aspect comprises: a first detection device having a first internal clock; and a second detection device having a second internal clock, wherein the first detection device comprises: a first excitation unit which generates vibrations whenever a condition related to time is satisfied; a first vibration pickup unit which detects the vibrations generated by the second detection device; a measuring unit which measures the time from when the first excitation unit generates the vibrations to when the first vibration pickup unit detects the vibrations; a determination unit which determines a mode based on whether the time measured by the determination unit is longer than a prescribed interval time; and a correction unit which, if it is determined to be a specific mode, determines whether to correct the deviation between the first internal clock and the second internal clock based on a reference time, and, if it is determined to be corrected, corrects the first internal clock or the second internal clock, wherein the second detection device comprises a second excitation unit which generates vibrations whenever a condition related to time is satisfied.

[0015] Effects of the Invention

[0016] According to one embodiment, it is possible to perform time synchronization taking into account the positional relationship between a plurality of sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a diagram showing a configuration example of a detection system according to the first embodiment.

[0018] Figure 2 It is a diagram showing a configuration example of a detection device according to the first embodiment.

[0019] Figure 3 It is a diagram showing a configuration example of a detection device.

[0020] Figure 4 It is a diagram showing an operation example of the detection system.

[0021] Figure 5 It is a diagram showing a configuration example of a detection device.

[0022] Figure 6 It is a diagram showing an operation example of the detection system.

[0023] Figure 7 It is a diagram showing a configuration example of a detection device.

[0024] Figure 8 It is a diagram showing an operation example of the detection system.

[0025] Fig. 9 It is a diagram showing a configuration example of a detection device.

[0026] Fig.10 It is a diagram showing an operation example of the detection system.

[0027] Fig.11 It is a diagram showing a configuration example of a detection device.

[0028] Fig.12 It is a diagram showing an operation example of the detection system.

[0029] Fig.13 This is a flowchart showing the processing flow of the detection device according to the first embodiment.

[0030] Fig.14 This is a diagram for explaining the first embodiment.

[0031] Fig.15 This is a diagram for explaining the second embodiment.

[0032] Fig.16 This is a diagram for explaining the third embodiment.

[0033] Fig.17 This is a diagram for explaining a hardware configuration example. DETAILED DESCRIPTION

[0034] Below, the embodiments of the detection device, time synchronization method, computer-readable recording medium, and detection system disclosed in the present application are described in detail based on the accompanying drawings. In addition, the present invention is not limited to the embodiments described herein. In addition, the same reference numerals are marked on the same elements and repeated descriptions are appropriately omitted. In addition, the various embodiments can be appropriately combined within the scope of non-contradiction.

[0035] [First embodiment]

[0036] use Figure 1 The configuration of the detection system according to the first embodiment will be described. Figure 1 It is a diagram showing a configuration example of a detection system according to the first embodiment.

[0037] like Figure 1 As shown in FIG. 1 , the detection system 1 includes a detection device 10a, a detection device 10b, a detection device 10c, and a detection device 10d. In the following description, the detection devices may be referred to as the detection device 10 without distinguishing each other.

[0038] The detection system 1 is a system for detecting abnormalities of an instrument. The instrument is, for example, a motor and a pump equipped in a workshop. The instrument always generates vibrations during operation. For example, when the instrument is physically damaged, it can be considered that the waveform (frequency, etc.) of the vibration generated by the instrument changes.

[0039] The detection device 10 is a sensor that detects vibrations with changed waveforms as abnormal vibrations. The detection system 1 can determine the source of the abnormal vibration based on the time when the detection device 10 detects the abnormal vibration, the transmission status of the vibration, the magnitude (including sound pressure), etc. Figure 1 There is a source of abnormal vibration at position 200.

[0040] At this time, if the internal clock of the detection device 10 deviates, the time when the abnormal vibration is detected is inaccurate. As a result, the detection system 1 cannot determine the source of the abnormal vibration with good accuracy. In addition, the deviation of the internal clock includes not only the absolute deviation relative to the accurate time, but also the relative deviation between the devices. In order for the detection system 1 to determine the source of the abnormal vibration, it is sufficient if there is no relative deviation of the internal clock between the detection devices 10.

[0041] In addition, as long as the detection system 1 includes a plurality of detection devices 10, the number of detection devices 10 included in the detection system 1 is not limited to Figure 1 Quantity shown.

[0042] The detection device 10 generates vibration. In addition, the detection device 10 detects vibration. In addition, it is assumed that the vibration includes sound. In addition, the propagation medium of the vibration can be any one of gas, liquid and solid. The detection device 10 can be set in the air or in water.

[0043] The detection device 10 determines whether the internal clock is deviated based on the result of comparing the time when the vibration is generated and the time when the vibration is detected, and appropriately corrects the internal clock according to the determination result.

[0044] In addition, the detection device 10 can also use a mechanism for detecting vibrations for detecting abnormalities of the instrument for time synchronization. On the other hand, the detection device 10 can be a sensor that detects abnormalities of the instrument based on other information such as images or pressure instead of vibrations. In this case, a mechanism for detecting vibrations for the purpose of time synchronization is additionally provided for the detection device 10.

[0045] In addition, the internal clock deviation can also be determined by using GPS (Global Positioning System) or the Internet. On the other hand, GPS and the Internet cannot be used in an environment where radio waves are isolated. In contrast, the detection device 10 of this embodiment can determine the internal clock deviation even in an environment where GPS and the Internet cannot be used.

[0046] use Figure 2 The structure of the detection device 10 will be described. Figure 2It is a diagram showing a configuration example of a detection device according to the first embodiment.

[0047] like Figure 2 As shown, the detection device 10 includes an excitation unit 11, a vibration pickup unit 12, a clock unit 13, a control unit 14, and a storage unit 15. In addition, the detection device 10 may include a communication unit (eg, a network interface card) for performing wired or wireless data communication.

[0048] The excitation unit 11 is a device that generates vibration (including sound) of a specified frequency. For example, the excitation unit 11 is an exciter or a speaker.

[0049] The vibration pickup unit 12 is a device for detecting vibration (including sound). For example, the vibration pickup unit 12 is a vibration sensor or a microphone.

[0050] The clock unit 13 is a device that functions as an internal clock. For example, the clock unit 13 includes a crystal oscillator and an oscillation circuit. The clock unit 13 outputs the current time.

[0051] The control unit 14 is a processing unit that manages the entire detection device 10. The control unit 14 is a computing device such as a CPU (Central Processing Unit) or a microcomputer having a processor. The control unit 14 includes a determination unit 141, a measurement unit 142, and a calibration unit 143.

[0052] The determination unit 141 determines the mode based on whether the time measured by the measuring unit 142 is longer than a predetermined interval time. The determination unit 141 determines whether the mode of the detection device 10 is the pre-setting mode or the post-setting mode. The measuring unit 142 measures the time from when the excitation unit 11 generates vibration to when the vibration pickup unit 12 detects the vibration. When it is determined to be a specific mode (for example, the post-setting mode described later), the correction unit 143 determines whether to correct the deviation of the internal clock based on the reference time, and corrects the internal clock as needed.

[0053] In this way, the detection device 10 has a plurality of modes according to the positional relationship with respect to other detection devices 10. The detection device 10 changes the process related to the correction of the internal clock deviation according to the mode, thereby being able to perform time synchronization in consideration of the positional relationship between the plurality of sensors.

[0054] The storage unit 15 stores various data and various programs executed by the control unit 14. For example, the storage unit 15 is a storage device such as a HDD (Hard Disk Drive), an SSD (Solid State Drive), or a flash memory. The storage unit 15 stores various data generated in the processing executed by the detection device 10, such as data obtained during the execution of various processing by the control unit 14 and processing results obtained by executing various processing.

[0055] The storage unit stores the interval information 151. The interval information 151 is a predetermined interval time set in advance. The interval time will be described in detail later.

[0056] Here, a plurality of arrangement examples of the detection device 10 and an operation example of the detection system 1 in each arrangement example will be described.

[0057] [Configuration example 1: Two detection devices approaching each other]

[0058] Figure 3 FIG. 1 is a diagram showing an example of the configuration of a detection device. Figure 3 As shown, before the detection system 1 starts to operate, the detection device 10a and the detection device 10b are arranged close to each other. Here, close means that the distance between the devices is small enough, including the distance between the devices is 0, that is, the devices are close to each other.

[0059] Figure 4 It means Figure 3 The following is a diagram showing an example of the operation of the detection system corresponding to the configuration example. Figure 4 In the accompanying drawings showing examples of actions, a solid rectangle and a dotted rectangle are arranged on a straight line representing a time series corresponding to each detection device 10. The solid rectangle refers to the generation of vibration. In addition, the dotted rectangle refers to the detection of vibration. In addition, the number marked with a number after t represents the time. In addition, a subtraction operation such as txxx-tyyy represents the length of time from time txxx to time yyy (where xxx and yyy are numbers).

[0060] Whenever a time-related condition is met, the detection device 10a and the detection device 10b generate vibrations. The time-related condition may be that a cycle time has passed after the detection device detects the vibration, or that a cycle time specified based on a preset time has passed, or that a time set by a timer has arrived. In the present embodiment, the detection device 10a and the detection device 10b generate vibrations within each preset cycle time. The cycle time may be a short time such as a few seconds (for example, 2 seconds or 3 seconds), or a longer time greater than or equal to several tens of minutes (for example, 30 minutes or 60 minutes). Figure 4 In the example, the cycle time is 2 seconds. In addition, the interval time between the time when the detection device 10a generates vibration and the time when the detection device 10b generates vibration is set to 1 second.

[0061] In this case, a situation in which detection device 10 b vibrates 1 second after detection device 10 a vibrates, and detection device 10 a vibrates 1 second later repeatedly occurs.

[0062] like Figure 4As shown, the detection device 10a generates vibration at t101. In addition, the detection device 10b detects the vibration generated by the detection device 10a at t101. In addition, the detection device 10b generates vibration at t102. In addition, the detection device 10a detects the vibration generated by the detection device 10b at t102 at t102.

[0063] The detection device 10a measures t102-t101. Figure 4 As shown, if t102-t101 is equal to the interval time, the detection device 10a determines the mode to be the pre-setting mode.

[0064] In addition, at the time of starting the operation, the detection device 10a and the detection device 10b are in the hands of the user, and the detection device 10a and the detection device 10b are arranged close to each other, and it is confirmed that the mode before setting is determined. Then, the detection device 10a and the detection device 10b are arranged to be separated from each other (for example, arranged at positions far away from each other in the workshop), and the mode after setting is changed. Here, the user can adjust the internal clock.

[0065] Assuming that t102 - t101 is shorter than the interval time, the internal clock of the detection device 10a or the detection device 10b may be inaccurate and needs to be adjusted.

[0066] In addition, the detection device 10a may be notified of the current mode by the user, etc. If the detection device 10a is notified that the current mode is the pre-setting mode and t102-t101 is longer than the interval time, the internal clock of the detection device 10a or the detection device 10b may be inaccurate and needs to be adjusted.

[0067] Here, in fact, even when the detection device 10a and the detection device 10b are close to each other, the time for vibration propagation inside the device (hereinafter referred to as the shortest propagation time) will be generated. In the description so far, it is assumed that the detection device 10a ignores the shortest propagation time, but the detection device 10a can also determine the mode based on the consideration of the shortest propagation time.

[0068] The shortest propagation time is set to ε. For example, the detection device 10a determines the mode based on whether t102-t101-ε is longer or shorter than the interval time. Alternatively, the interval time may be set in advance in consideration of the shortest propagation time.

[0069] The vibration is assumed to be sound propagating in the air, and the temperature is assumed to be 20°C. In this case, the speed of sound is 343.59 (m / s) = 34.359 (cm / s). In addition, the thickness of the air layer that propagates the sound between the approaching detection device 10a and the detection device 10b is assumed to be 1 cm. Thus, the shortest propagation speed ε is as shown in formula (1). The shortest propagation speed ε varies depending on the shape of the detection device 10 and the degree of proximity.

[0070] ε=1(cm) / 34.359(cm / s)=2.91×10 -5 ≈30μs (1)

[0071] In the following description, it is assumed that the detection device 10 ignores the shortest propagation time. However, as described here, the detection device 10 may perform processing in consideration of the shortest propagation time.

[0072] In addition, if the deviation of the internal clock generated when the shortest propagation time is ignored is within the allowable range during operation, the detection device 10a and the detection device 10b can be considered to be close to each other. For example, when the deviation of the internal clock is allowed up to 60μs (30μs×2), if the thickness of the air layer through which the sound is propagated is configured to be within 2cm (1cm×2), the detection device 10a and the detection device 10b are considered to be close.

[0073] [Configuration example 2: 2 separate detection devices]

[0074] Figure 5 FIG. 1 is a diagram showing an example of the configuration of a detection device. Figure 5 As shown, when the detection system 1 is used, the detection device 10a and the detection device 10b are configured separately from each other.

[0075] Figure 6 It means Figure 5 Figure 1 shows an example of the operation of the detection system corresponding to the configuration example of Figure 4 Similarly, the cycle time is 2 seconds and the interval time is 1 second. In this case, the following situation occurs repeatedly, that is, 1 second after the detection device 10a generates vibration, the detection device 10b generates vibration, and 1 second after the detection device 10a generates vibration. In addition, it can be set as follows, that is, when the user does not adjust the internal clock of the detection device, the detection device 10a generates vibration, and after the first time (for example, 1 second) relative to the moment when the detection device 10b detects the vibration, the detection device 10b generates vibration, and the detection device 10a detects the vibration.

[0076] like Figure 6As shown, the detection device 10a generates vibration at t201. In addition, the detection device 10b detects the vibration generated by the detection device 10a at t202. In addition, the detection device 10b generates vibration at t203. In addition, the detection device 10a detects the vibration generated by the detection device 10b at t203 at t204.

[0077] The detection device 10a measures t204-t201. If t204-t201 is longer than the interval time, the detection device 10a determines the mode as the post-setting mode. Figure 4 This is because the separation of the detection device 10a and the detection device 10b causes the vibration propagation time to be extended.

[0078] The detection device 10a stores t204-t201 as the reference time in advance. Furthermore, the detection device 10a continues to measure the time from the generation of vibration to the detection of the vibration generated by the detection device 10b, and compares the measured time with the reference time to determine whether the internal clock of the detection device 10a or the detection device 10b is deviated.

[0079] When the measured time is different from the reference time, the detection device 10a determines that the internal clock of the detection device 10a or the detection device 10b is deviated, and corrects the internal clock of one or both of them.

[0080] [Configuration example 3: 3 detection devices approaching each other]

[0081] The configuration and operation described above in the case where there are two detection devices 10 can be extended to the case where there are three or more detection devices 10.

[0082] Figure 7 FIG. 1 is a diagram showing an example of the configuration of a detection device. Figure 7 As shown, before the detection system 1 is used, the detection device 10a, the detection device 10b, and the detection device 10c are arranged closely.

[0083] Figure 8 It means Figure 7 The figure shows an example of the operation of the detection system corresponding to the configuration example of . The cycle time is 3 seconds. In addition, the interval time between the detection device 10a and the detection device 10b is 1 second. In addition, the interval time between the detection device 10a and the detection device 10c is 2 seconds. In this case, the following situation repeatedly occurs, that is, 1 second after the detection device 10a vibrates, the detection device 10b vibrates, 1 second after that, the detection device 10c vibrates, and 1 second after that, the detection device 10a vibrates.

[0084] like Figure 8As shown, the detection device 10a generates vibration at t301. In addition, the detection device 10b and the detection device 10c detect the vibration generated by the detection device 10a at t301 at t301.

[0085] In addition, the detection device 10b generates vibration at t302. In addition, the detection device 10a and the detection device 10c detect the vibration generated by the detection device 10b at t302 at t302.

[0086] In addition, the detection device 10c generates vibration at t303. In addition, the detection device 10a and the detection device 10b detect the vibration generated by the detection device 10c at t303 at t303.

[0087] The detection device 10a measures t302-t301. If t302-t301 is longer than the interval time relative to the detection device 10b, the detection device 10a determines the mode relative to the detection device 10b as the post-setting mode. If t302-t301 is equal to the interval time relative to the detection device 10b, the detection device 10a determines the mode relative to the detection device 10b as the pre-setting mode.

[0088] The detection device 10a measures t303-t301. If t303-t301 is longer than the interval time relative to the detection device 10c, the detection device 10a determines the mode relative to the detection device 10c as the post-setting mode. If t303-t301 is equal to the interval time relative to the detection device 10c, the detection device 10a determines the mode relative to the detection device 10c as the pre-setting mode.

[0089] In this way, the detection device 10a independently determines the mode with respect to the detection device 10b and with respect to the detection device 10c. Figure 8 In the example, the mode between the detection device 10a and the detection device 10b, and the mode between the detection device 10a and the detection device 10c are both pre-setting modes.

[0090] In this case, the detection device 10a sets reference times for each of the detection device 10b and the detection device 10c, and determines the deviation of the internal clock based on the respective reference times.

[0091] [Configuration example 4: 2 of 3 detection devices approaching]

[0092] Fig. 9 FIG. 1 is a diagram showing an example of the configuration of a detection device. Fig. 9 As shown, the detection device 10a and the detection device 10b are close to each other. In addition, the detection device 10c is separated from the detection device 10a and the detection device 10b.

[0093] Fig.10 It means Fig. 9 Figure 1 shows an example of the operation of the detection system corresponding to the configuration example of Figure 8 Similarly, the cycle time is 3 seconds. In addition, the interval time between the detection device 10a and the detection device 10b is 1 second. In addition, the interval time between the detection device 10a and the detection device 10c is 2 seconds. In this case, the following situation occurs repeatedly, that is, 1 second after the detection device 10a generates vibration, the detection device 10b generates vibration, 1 second after it, the detection device 10c generates vibration, and 1 second after the detection device 10a generates vibration. In addition, it can be set as the following action, that is, the detection device 10a generates vibration, and after the first time (for example, 1 second) after the detection device 10b detects the vibration, the detection device 10b generates vibration, and the detection device 10a detects the vibration. In addition, in this case, the detection device 10c can use the information of either or both after the second time (for example, 2 seconds) after the detection of the vibration generated by the detection device 10a, or after the first time after the detection of the vibration generated by the detection device 10b, to specify the vibration time of the detection device 10c itself and vibrate. In addition, as long as the second time is different from the first time.

[0094] like Fig.10 As shown, the detection device 10a generates vibration at t401. In addition, the detection device 10b detects the vibration generated by the detection device 10a at t401 at t401. In addition, the detection device 10c detects the vibration generated by the detection device 10a at t401 at t402.

[0095] The detection device 10b generates vibration at t403. In addition, the detection device 10a detects the vibration generated by the detection device 10b at t403 at t403. In addition, the detection device 10c detects the vibration generated by the detection device 10b at t403 at t404.

[0096] The detection device 10c generates vibration at t405. In addition, the detection device 10a detects the vibration generated by the detection device 10c at t405 at t406. In addition, the detection device 10b detects the vibration generated by the detection device 10c at t405 at t406.

[0097] The detection device 10a measures t403-t401. If t403-t401 is longer than the interval time relative to the detection device 10b, the detection device 10a determines the mode relative to the detection device 10b as the post-setting mode. If t403-t401 is equal to the interval time relative to the detection device 10b, the detection device 10a determines the mode relative to the detection device 10b as the pre-setting mode.

[0098] The detection device 10a measures t406-t401. If t406-t401 is longer than the interval time relative to the detection device 10c, the detection device 10a determines the mode relative to the detection device 10c as the post-setting mode. If t406-t401 is equal to the interval time relative to the detection device 10c, the detection device 10a determines the mode relative to the detection device 10c as the pre-setting mode.

[0099] exist Fig.10 In the example of FIG. 1 , the mode between the detection device 10a and the detection device 10b is the pre-setting mode. The mode between the detection device 10a and the detection device 10c is the post-setting mode.

[0100] [Configuration example 5: 3 detection devices separated from each other]

[0101] Fig.11 FIG. 1 is a diagram showing an example of the configuration of a detection device. Fig.11 As shown, the detection device 10a, the detection device 10b and the detection device 10c are separated from each other.

[0102] Fig.12 It means Fig.11 Figure 1 shows an example of the operation of the detection system corresponding to the configuration example of Figure 8 Similarly, the cycle time is 3 seconds. In addition, the interval time between the detection device 10a and the detection device 10b is 1 second. In addition, the interval time between the detection device 10a and the detection device 10c is 2 seconds. In this case, the following situation occurs repeatedly, that is, 1 second after the detection device 10a generates vibration, the detection device 10b generates vibration, 1 second after it, the detection device 10c generates vibration, and 1 second after the detection device 10a generates vibration. In addition, it can be set as the following action, that is, the detection device 10a generates vibration, and the detection device 10b generates vibration after the first time (for example, 1 second) after the detection device 10b detects the vibration, and the detection device 10a detects the vibration. In addition, in this case, the detection device 10c can use the information of either or both after the second time (for example, 2 seconds) after the detection of the vibration generated by the detection device 10a, or after 1 second after the detection of the vibration generated by the detection device 10b, to specify the vibration timing of the detection device 10c itself and vibrate.

[0103] like Fig.12 As shown, the detection device 10a generates vibration at t501. In addition, the detection device 10b detects the vibration generated by the detection device 10a at t501 at t502. In addition, the detection device 10c detects the vibration generated by the detection device 10a at t501 at t503.

[0104] The detection device 10b generates vibration at t504. In addition, the detection device 10a detects the vibration generated by the detection device 10b at t504 at t505. In addition, the detection device 10c detects the vibration generated by the detection device 10b at t504 at t506.

[0105] The detection device 10c generates vibration at t507. In addition, the detection device 10a detects the vibration generated by the detection device 10c at t507 at t509. In addition, the detection device 10b detects the vibration generated by the detection device 10c at t507 at t508.

[0106] The detection device 10a measures t505-t501. If t505-t501 is longer than the interval time relative to the detection device 10b, the detection device 10a determines the mode relative to the detection device 10b as the post-setting mode. If t505-t501 is equal to the interval time relative to the detection device 10b, the detection device 10a determines the mode relative to the detection device 10b as the pre-setting mode.

[0107] The detection device 10a measures t509-t501. If t509-t501 is longer than the interval time relative to the detection device 10c, the detection device 10a determines the mode relative to the detection device 10c as the post-setting mode. If t509-t501 is equal to the interval time relative to the detection device 10c, the detection device 10a determines the mode relative to the detection device 10c as the pre-setting mode.

[0108] exist Fig.12 In the example, the mode between the detection device 10a and the detection device 10b, and the mode between the detection device 10a and the detection device 10c are both post-setting modes.

[0109] In addition, when there are three or more detection devices 10, the frequencies of vibrations generated by the detection devices 10 can be set to be different, thereby distinguishing the detection devices 10 that generate the vibrations. For example, the detection device 10a generates a vibration of 1 kHz, the detection device 10b generates a vibration of 2 kHz, and the detection device 10c generates a vibration of 3 kHz. The vibration pickup unit 12 can separate the vibration of a specific frequency from the detected vibration.

[0110] [Processing Flow of the First Embodiment]

[0111] use Fig.13 The processing flow of the detection device 10 is described. Fig.131 is a flowchart showing the processing flow of the detection device involved in the first embodiment. In addition, here, it is assumed that the detection system 1 includes the detection device 10a and the detection device 10b. However, the configuration of the detection device 10a and the detection device 10b is assumed to be unknown. In addition, the processing subject of the flowchart is set to the detection device 10a.

[0112] like Figure 1 As shown in FIG. 1 , when the power is turned on, the detection device 10a starts processing (step S101). At this time, the mode of the detection device 10a is not determined.

[0113] The detection device 10a generates vibration (step S102). The vibration generated by the detection device 10a is detected by the detection device 10b. The detection device 10a generates vibration every time a time-related condition is satisfied.

[0114] Next, the detection device 10a detects vibration (step S103). The detection device 10a detects the vibration generated by the detection device 10b.

[0115] The detection device 10a measures the time from the generation of vibration to the detection of vibration (step S104). Here, if the mode with respect to the detection device 10b has not been determined (No in step S105), the detection device 10a proceeds to step S106. On the other hand, if the mode with respect to the detection device 10b has been determined (Yes in step S105), the detection device 10a proceeds to step S111.

[0116] In step S106, if the measured time is not longer than the interval time (e.g., equal to the interval time) (No in step S106), the detection device 10a determines the mode with respect to the detection device 10b to be the pre-setting mode (step S107). Furthermore, the detection device 10a sets the interval time as the reference time (step S108). In addition, here, the case where the measured time is shorter than the interval time and the case where the user or the like notifies the detection device 10a of the current mode are not considered.

[0117] In this way, when the measured time is not longer than the interval time, the detection device 10a determines the mode to be the pre-setting mode in which the detection device 10a and the detection device 10b are close. Furthermore, when it is determined that the mode is the pre-setting mode, the detection device 10a sets the interval time as the reference time, and determines whether to correct the deviation of the internal clocks of the detection device 10a and the detection device 10b based on the difference between the time measured after the reference time is set and the reference time. Thus, the detection device 10a can correct the deviation of the internal clock in advance before operation in the pre-setting mode.

[0118] Furthermore, when the mode is determined to be the pre-setting mode, the detection device 10a may set the time obtained by adding the time (shortest propagation time) of vibration propagation between the detection devices 10a and 10b close to each other to the interval time as the reference time, and determine whether to correct the deviation of the internal clocks of the detection devices 10a and 10b based on the difference between the time measured after the reference time is set and the reference time. Thus, the detection device 10a can determine the mode more accurately by taking into account the shortest propagation time.

[0119] In step S106, if the measured time is longer than the interval time (Yes in step S106), the detection device 10a determines the mode with respect to the detection device 10b to be the post-setting mode (step S109). Furthermore, the detection device 10a sets the measured time as the reference time (step S110).

[0120] Thus, when the measured time is longer than the interval time, the detection device 10a determines the mode as the post-setup mode in which the detection device 10a and the detection device 10b are separated. Furthermore, when the mode is determined as the post-setup mode, the detection device 10a sets the measured time as the reference time, and determines whether to correct the deviation of the internal clocks of the detection device 10a and the detection device 10b based on the difference between the time measured after the reference time is set and the reference time. Thus, in the post-setup mode, the detection device 10a can correct the deviation of the internal clock even in operation.

[0121] In step S111, the detection device 10a performs a correction process based on the reference time (step S111). In the correction process, the detection device 10a compares the measured time with the reference time to determine whether the internal clock is deviated, and corrects the internal clock if it is determined that there is a deviation.

[0122] For example, when the difference between the measured time and the reference time is greater than or equal to a threshold, the detection device 10a determines to correct the deviation between the internal clocks of the detection device 10a and the detection device 10b. Thus, the detection device 10a can take into account the error between the measured time and the reference time according to the threshold.

[0123] In step S112, when the detection device 10a continues to operate (Yes in step S112), the process waits until the condition related to time is satisfied (step S113), and then returns to step S102 to repeat the process.

[0124] If the detection device 10a is not continuously operating (No in step S112), the process is terminated. For example, if the shutdown process is started or a command to explicitly terminate the process is received, the detection device 10a does not continuously operate.

[0125] In step S106, the detection device 10a may determine the setting mode differently from the pre-setting mode and the post-setting mode. If the detection device 10a determines that it is the setting mode, it returns to step S102 and continues to determine the mode.

[0126] Next, a method for determining the setting mode is described. However, the method for determining the setting mode is not limited to the method described here. First, the detection device 10a confirms whether the frequency of the detected vibration is the minimum frequency vibration among the vibrations detected after the power is turned on. If it is not the minimum frequency, the detection device 10a returns the process to step S102.

[0127] In addition, when the detected vibration is the minimum frequency vibration, the detection device 10a calculates the time fluctuation of the constant measured in the past. When the fluctuation is greater than the threshold, the detection device 10a determines that the position of the detection device 10a or the detection device 10b is not fixed, that is, the setting mode.

[0128] [First embodiment]

[0129] An embodiment of the detection system 1 will be described. Fig.14 This is a diagram for explaining the first embodiment. Fig.14 As shown, the detection system 1 is configured in a facility having a valve 211 , a valve 212 , a pump 213 , and a motor 214 .

[0130] For example, the detection device 10a strongly collects the process (fluid) sound of the pump 213. In addition, the detection device 10b strongly collects the sound of the pump 213. In addition, the detection device 10d strongly collects the sound of the motor 214. In this way, each detection device 10 strongly collects nearby sounds.

[0131] If the time is accurately synchronized, the sound collected by the detection device 10b can be subtracted from the sound collected by the detection device 10a to make the sound of the process prominent. In addition, the detection system 1 can perform beamforming based on the sound collected by each detection device 10 and identify the position of the sound source.

[0132] [Second embodiment]

[0133] Fig.15 The magnitude of the sound detected by each detection device 10 is determined based on the relative Figure 5The detection system 1 can determine the position of the sound source 221 according to the distance relative to the plurality of detection devices 10. Furthermore, if the detection device 10 can detect the directionality of the sound, the detection system 1 can determine the position of the sound source 221 more accurately.

[0134] [Third embodiment]

[0135] Fig.16 This is a diagram for explaining the third embodiment. Fig.16 As shown, each detection device 10 can detect sounds from multiple sound sources. For example, based on the sounds collected by the detection device 10a and the detection device 10b and the time difference, the sounds of the motor 231, the pump 232, and the container 233 can be separated. And by separating the sounds, the location where the abnormal sound occurs can be determined. That is, in the third embodiment, beamforming can be performed.

[0136] [About how to adjust the internal clock]

[0137] The detection device 10a can calibrate the internal clock through the following procedure. Here, a pre-installation mode in which the detection device 10a and the detection device 10b are close to each other is considered.

[0138] First, the detection device 10a generates vibration when its internal clock reaches the time 0:00:00.00 (hour:minute:second). Then, the detection device 10b detects vibration when its internal clock reaches the time 0:00:00.00.

[0139] Furthermore, the detection device 10a vibrates at the time 1:00:00.01 of its internal clock about one hour later. Furthermore, the detection device 10b detects vibration at the time 1:00:00.31 of its internal clock. This means that the internal clocks of the detection device 10a and the detection device 10b deviate relatively at 0:00:00.30 within one hour (60 minutes).

[0140] Therefore, thereafter, the detection device 10a, for example, adds 0:00:00.01 to its own internal clock every 2 minutes. Alternatively, the detection device 10b subtracts 0:00:00.01 from its own internal clock every 2 minutes. The detection device 10 may not be limited to 2 minutes, but may perform corrections (addition and subtraction) at a higher frequency or a lower frequency. In addition, the detection device 10 may adjust the clock of the crystal oscillator by adjusting the voltage, etc., or adjust the correction by changing the division ratio of the clock of the crystal oscillator. For example, addition and subtraction of the internal clock may be performed by adjusting the clock time of the crystal oscillator. The detection device 10 is capable of performing addition and subtraction at a finer order of magnitude by performing corrections at a high frequency (for example, every 1 millisecond). For example, the detection device 10 is also capable of performing addition operations in μ-second units such as 100μs+1μs through soft processing.

[0141] In this mode, the detection devices are in the same place, so the temperature and other conditions are the same. Therefore, the deviation of the internal clock depends on the individual difference of the crystal oscillator or the transmission circuit itself, and the individual difference is grasped and corrected. On the other hand, in the post-setup mode, the detection devices are installed in different places, so there are cases where the temperature of the detection devices is different. Due to this temperature difference, etc., the time deviation occurs, so the time is corrected regularly in the post-setup mode. The surrounding environment such as temperature can be estimated based on this correction information.

[0142] Here, when the mode is determined to be the pre-setting mode by the determination unit 141, the correction unit 143 records the first deviation of the first internal clock and the second internal clock based on the difference between the time measured by the measurement unit 142 and the reference time, and when the mode is determined to be the post-setting mode by the determination unit 141, the correction unit 143 records the second deviation of the first internal clock and the second internal clock based on the difference between the time measured by the measurement unit 142 and the reference time. For example, the correction unit 143 calculates the first deviation and the second deviation and stores them in the storage unit 15 together with the time stamp. It can be considered that the first deviation is generated due to individual differences in the transmission circuit such as the crystal oscillator. In addition, it can be considered that the second deviation is generated due to the surrounding environment (such as temperature) of the detection device 10. Therefore, by comparing the first deviation and the second deviation, the change in the surrounding environment between the pre-setting mode and the post-setting mode of the detection device 10 can be estimated. For example, it can be considered that the larger the first deviation and the second deviation are, the larger the ambient temperature difference between the pre-setting mode and the post-setting mode of the detection device 10 is.

[0143] [system]

[0144] The information including the processing sequence, control sequence, specific names, various data, and parameters described above and shown in the drawings can be arbitrarily changed except for cases where special description is given.

[0145] In addition, the structural elements of each device shown in the figure are functional concepts and do not necessarily need to be physically configured as shown in the figure. In other words, the specific method of dispersing and integrating each device is not limited to the method shown in the figure. In other words, all or part of them can be functionally or physically dispersed / integrated in any unit according to various loads, usage conditions, etc.

[0146] Furthermore, all or any part of each processing function performed by each device may be realized by a CPU and a program analyzed and executed by the CPU, or may be realized as hardware based on wired logic.

[0147] [hardware]

[0148] Next, a hardware configuration example of the detection device 10 will be described. Fig.17 This is a diagram for explaining a hardware configuration example.

[0149] like Fig.17 As shown, the detection device 10 includes a communication device 100a, a HDD 100b, a memory 100c, and a processor 100d. Fig.17 The various components shown are connected to each other by a bus or the like.

[0150] The communication device 100a is a network interface card or the like, and performs communication with other devices. Figure 2 The functions shown are stored in programs and DBs that execute actions.

[0151] The processor 100d reads and executes data from the HDD 100b or the like. Figure 2 The same processing program is developed in the memory 100c for each processing unit as shown in FIG. Figure 2 The process of each function described in the above etc. executes the action. For example, this process executes the same function as each processing unit of the detection device 10. Specifically, the processor 100d reads a program having the same function as the determination unit 141, the measurement unit 142, and the correction unit 143 from the HDD 100b etc. Then, the processor 100d executes the following process, that is, executes the same processing as the determination unit 141, the measurement unit 142, and the correction unit 143.

[0152] In this way, the detection device 10 performs an action as a detection device that executes the time synchronization method by reading and executing the program. In addition, the detection device 10 can also use a medium reading device to read the above program from the recording medium and execute the read program, thereby realizing the same function as the above embodiment. In addition, the program described in other embodiments is not limited to being executed by the detection device 10. For example, when other computers or servers execute the program, and when they cooperate to execute the program, the present invention can also be applied in the same way.

[0153] The program can be deployed via a network such as the Internet. In addition, the program can be recorded on a computer-readable recording medium such as a hard disk, a floppy disk (FD), a CD-ROM, an MO (Magneto-Optical disk), or a DVD (Digital Versatile Disc), and read from the recording medium by a computer for execution.

[0154] Several examples of combinations of disclosed technical features are described below.

[0155] (1) A detection device, characterized in that:

[0156] The detection device comprises:

[0157] Internal clock;

[0158] an excitation unit that generates vibrations whenever a time-related condition is met;

[0159] a vibration pickup portion that detects vibration;

[0160] a measuring unit that measures a time from when the excitation unit generates vibration to when the vibration pickup unit detects the vibration;

[0161] a determination unit that determines a mode based on whether the time measured by the measurement unit is longer than a predetermined interval time; and

[0162] A correction unit determines whether to correct the deviation of the internal clock based on a reference time when it is determined that the specific mode is selected, and corrects the internal clock when it is determined that the deviation is corrected.

[0163] (2) A time synchronization method, which is a time synchronization method performed by a detection device,

[0164] The detection device has:

[0165] Internal clock;

[0166] an excitation unit that generates vibrations whenever a time-related condition is satisfied; and

[0167] A vibration pickup unit detects vibration. The time synchronization method is characterized in that it includes the following steps:

[0168] a measuring step of measuring the time from when the excitation unit generates vibration to when the vibration pickup unit detects the vibration;

[0169] a determination step of determining a mode based on whether the time measured by the measurement step is longer than a predetermined interval time; and

[0170] The correction step determines whether to correct the deviation of the internal clock based on a reference time when it is determined that the specific mode is selected, and corrects the internal clock when it is determined that the deviation of the internal clock is selected.

[0171] (3) A computer-readable recording medium having a time synchronization program recorded thereon, wherein the time synchronization program causes a detection device to execute a measurement step, a determination step, and a correction step,

[0172] The detection device comprises:

[0173] Internal clock;

[0174] an excitation unit that generates vibrations whenever a time-related condition is satisfied; and

[0175] a vibration pickup portion, the vibration pickup portion detecting vibration,

[0176] In the measuring step, the time from when the excitation unit generates vibration to when the vibration pickup unit detects the vibration is measured.

[0177] In the determination step, the mode is determined based on whether the time measured in the measurement step is longer than a predetermined interval time.

[0178] In the correction step, when it is determined that the specific mode is selected, it is determined based on a reference time whether to correct the deviation of the internal clock, and when it is determined that the deviation is to be corrected, the internal clock is corrected.

[0179] (4) A detection system comprising: a first detection device having a first internal clock; and a second detection device having a second internal clock, wherein:

[0180] The first detection device comprises:

[0181] a first excitation unit that generates vibrations whenever a time-related condition is satisfied;

[0182] a first vibration pickup portion for detecting vibration generated by the second detection device;

[0183] a measuring unit that measures a time from when the first excitation unit generates vibration to when the first vibration pickup unit detects the vibration;

[0184] a determination unit that determines a mode based on whether the time measured by the measurement unit is longer than a predetermined interval time; and

[0185] a correction unit that, when it is determined that the specific mode is selected, determines based on a reference time whether to correct the deviation between the first internal clock and the second internal clock, and, when it is determined that the deviation is corrected, corrects the first internal clock or the second internal clock,

[0186] The second detection device includes a second excitation unit that generates vibrations whenever a time-related condition is satisfied.

[0187] (5) The detection system according to (4), characterized in that:

[0188] When the time measured by the measuring unit is not longer than the interval time, the determining unit determines that the mode is a pre-installation mode in which the first detection device and the second detection device are close to each other.

[0189] (6) The detection system according to (4) or (5), characterized in that:

[0190] When the mode is determined by the determination unit to be the pre-setting mode, the correction unit sets the interval time as the reference time, and determines whether to correct the deviation between the first internal clock and the second internal clock based on the difference between the time measured by the measurement unit after the reference time is set and the reference time.

[0191] (7) The detection system according to any one of (4) to (6), characterized in that:

[0192] When the determination unit determines that the mode is the pre-setting mode, the correction unit sets the time obtained by adding the interval time to the time for vibration propagation between the first detection device and the second detection device which are close to each other as the reference time, and determines whether to correct the deviation between the first internal clock and the second internal clock based on the difference between the time measured by the measuring unit after the reference time is set and the reference time.

[0193] (8) The detection system according to any one of (4) to (7), characterized in that:

[0194] When the time measured by the measuring unit is longer than the interval time, the determining unit determines that the mode is a post-installation mode in which the first detection device and the second detection device are separated.

[0195] (9) The detection system according to any one of (4) to (8), characterized in that:

[0196] When the determination unit determines that the mode is the post-setting mode, the correction unit sets the time measured by the measuring unit as the reference time, and determines whether to correct the deviation between the first internal clock and the second internal clock based on the difference between the time measured by the measuring unit after the reference time is set and the reference time.

[0197] (10) The detection system according to any one of (4) to (9), characterized in that:

[0198] The determination unit determines to correct the deviation between the first internal clock and the second internal clock when the difference between the time measured by the measurement unit and the reference time is greater than or equal to a threshold value.

[0199] (11) The detection system according to any one of (4) to (10), characterized in that:

[0200] When the determination unit determines that the mode is the pre-setting mode, the correction unit records the first deviation between the first internal clock and the second internal clock based on the difference between the time measured by the measuring unit and the reference time. When the determination unit determines that the mode is the post-setting mode, the correction unit records the second deviation between the first internal clock and the second internal clock based on the difference between the time measured by the measuring unit and the reference time.

[0201] Description of the label

[0202] 1. Detection system

[0203] 10, 10a, 10b, 10c, 10d detection device

[0204] 11 Excitation unit

[0205] 12. Vibration pickup unit

[0206] 13 Clock

[0207] 14. Control Unit

[0208] 15 Storage

[0209] 141 Judgment Department

[0210] 142 Measurement Department

[0211] 143 Correction Department

[0212] 151 interval information

Claims

1. A detection device, characterized in that: The detection device comprises: Internal clock; an excitation unit that generates vibrations whenever a time-related condition is met; a vibration pickup portion that detects vibration; a measuring unit that measures a time from when the excitation unit generates vibration to when the vibration pickup unit detects the vibration; a determination unit that determines a mode based on whether the time measured by the measurement unit is longer than a predetermined interval time; as well as A correction unit determines whether to correct the deviation of the internal clock based on a reference time when it is determined that the specific mode is selected, and corrects the internal clock when it is determined that the deviation is corrected.

2. A time synchronization method, which is a time synchronization method performed by a detection device, The detection device has: Internal clock; an excitation unit that generates vibrations whenever a time-related condition is satisfied; and a vibration pickup portion, the vibration pickup portion detecting vibration, The time synchronization method is characterized in that it includes the following steps: a measuring step of measuring the time from when the excitation unit generates vibration to when the vibration pickup unit detects the vibration; a determination step of determining a mode based on whether the time measured by the measurement step is longer than a predetermined interval time; and The correction step determines whether to correct the deviation of the internal clock based on a reference time when it is determined that the specific mode is selected, and corrects the internal clock when it is determined that the deviation of the internal clock is selected.

3. A computer-readable recording medium having a time synchronization program recorded thereon, characterized in that: The time synchronization program causes the detection device to execute a measurement step, a determination step, and a calibration step. The detection device comprises: Internal clock; an excitation unit that generates vibrations whenever a time-related condition is satisfied; and a vibration pickup portion, the vibration pickup portion detecting vibration, In the measuring step, the time from when the excitation unit generates vibration to when the vibration pickup unit detects the vibration is measured. In the determination step, the mode is determined based on whether the time measured in the measurement step is longer than a predetermined interval time. In the correction step, when it is determined that the specific mode is selected, it is determined based on a reference time whether to correct the deviation of the internal clock, and when it is determined that the deviation is to be corrected, the internal clock is corrected.

4. A detection system comprising: a first detection device having a first internal clock; and a second detection device having a second internal clock, The detection system is characterized in that The first detection device comprises: a first excitation unit that generates vibrations whenever a time-related condition is satisfied; a first vibration pickup portion for detecting vibration generated by the second detection device; a measuring unit that measures a time from when the first excitation unit generates vibration to when the first vibration pickup unit detects the vibration; a determination unit that determines a mode based on whether the time measured by the measurement unit is longer than a predetermined interval time; as well as a correction unit that, when it is determined that the specific mode is selected, determines based on a reference time whether to correct the deviation between the first internal clock and the second internal clock, and, when it is determined that the deviation is corrected, corrects the first internal clock or the second internal clock, The second detection device includes a second excitation unit that generates vibrations whenever a time-related condition is satisfied.

5. The detection system according to claim 4, characterized in that: When the time measured by the measuring unit is not longer than the interval time, the determining unit determines that the mode is a pre-installation mode in which the first detection device and the second detection device are close to each other.

6. The detection system according to claim 5, characterized in that: When the mode is determined by the determination unit to be the pre-setting mode, the correction unit sets the interval time as the reference time, and determines whether to correct the deviation between the first internal clock and the second internal clock based on the difference between the time measured by the measurement unit after the reference time is set and the reference time.

7. The detection system according to claim 5, characterized in that: When the determination unit determines that the mode is the pre-setting mode, the correction unit sets the time obtained by adding the interval time to the time for vibration propagation between the first detection device and the second detection device which are close to each other as the reference time, and determines whether to correct the deviation between the first internal clock and the second internal clock based on the difference between the time measured by the measuring unit after the reference time is set and the reference time.

8. The detection system according to claim 4, characterized in that: When the time measured by the measuring unit is longer than the interval time, the determining unit determines that the mode is a post-installation mode in which the first detection device and the second detection device are separated.

9. The detection system according to claim 8, characterized in that: When the determination unit determines that the mode is the post-setting mode, the correction unit sets the time measured by the measuring unit as the reference time, and determines whether to correct the deviation between the first internal clock and the second internal clock based on the difference between the time measured by the measuring unit after the reference time is set and the reference time.

10. The detection system according to claim 4, characterized in that: The determination unit determines to correct the deviation between the first internal clock and the second internal clock when the difference between the time measured by the measurement unit and the reference time is greater than or equal to a threshold value.

11. The detection system according to claim 4, characterized in that: When the determination unit determines that the mode is the pre-setting mode, the correction unit records the first deviation between the first internal clock and the second internal clock based on the difference between the time measured by the measuring unit and the reference time. When the determination unit determines that the mode is the post-setting mode, the correction unit records the second deviation between the first internal clock and the second internal clock based on the difference between the time measured by the measuring unit and the reference time.

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