Sensor data transmission amount reduction device using frequency conversion

Abstract

The present invention relates to a configuration for transmitting vibration data measured from a rotating body, such as a rotating device, to a remote management server, and analyzing a frequency by converting the vibration data into a frequency domain. And transmitting the data packet to a management server by changing the configuration of the data packet according to the analysis information. The present invention comprises: a signal processor for converting a detection signal into a frequency domain; a frequency analysis means for analyzing the composition of the frequency; and a packet generation unit that generates a packet on the basis of the composition of the frequency.

Description

Technical Field

[0001] The present invention relates to a vibration sensor data transmission volume reduction technology utilizing frequency conversion, and more specifically, to a sensor data transmission volume reduction device utilizing frequency conversion, which sends vibration data measured from a rotating body such as a rotating device to a remote management server, analyzes the frequency composition by converting the vibration data into the frequency domain, and changes the composition of the data packet based on the analysis information and transmits it to the management server. Background Art

[0002] A turbine is a mechanical device that uses the flow of a compressible fluid such as steam or gas to obtain rotational force through impact force or reaction force. It includes a steam turbine that uses steam and a gas turbine that uses high-temperature combustion gas.

[0003] Turbine blades are core components that convert the thermal energy of steam or combustion gas into mechanical energy to generate electricity. When turbine blades are damaged, it will cause serious accidents to the entire power generation facility including the turbine.

[0004] Vibration is a typical cause of damage to turbine blades. Specifically, when turbine blades rotate, vibrations are generated in the radial direction, and stress is concentrated at a specific position, which may cause cracks and fatigue damage.

[0005] Therefore, in order to prevent damage to turbine blades, it is necessary to have a method and system for detecting vibration of the blades when the turbine is operating.

[0006] Korean Patent No. 10-2456262 (hereinafter referred to as the prior art) proposes a technology for predicting the load and life of a wind turbine based on vibration. In the prior art, a large amount of data is accumulated on a main server through a communication module. However, since the vibration data generated by the rotating equipment (i.e., turbine or motor) is generated in large quantities at a high speed of about 20MByte to 200MByte / sec, there is a limit to receiving a large amount of vibration data from the server through low-speed wireless communication.

[0007] In addition, if the sampling rate is simply lowered in order to reduce the size of the transmitted data, it may be difficult to restore the digital signal to a vibration signal, and operating at the same sampling rate may also result in unnecessary waste of power.

[0008] Patent document: Korean Patent Gazette No. 10-2456262 (2022.10.14) Summary of the invention

[0009] Technical Problems to be Solved by the Invention

[0010] The problem to be solved by the present invention is to provide a sensor data transmission amount reduction device utilizing frequency conversion, which sends vibration data measured from a rotating body such as a rotating device to a remote management server, analyzes the frequency composition by converting the vibration data into a frequency domain, changes the composition of the data packet based on the analysis information, and transmits it to the management server.

[0011] Technical Solution

[0012] Plan to write (copy the claims) after your firm completes its response.

[0013] Effects of the Invention

[0014] According to an embodiment of the present invention, vibration data measured from a rotating body such as a rotating device is sent to a remote management server, the frequency composition is analyzed by converting the vibration data into the frequency domain, and the composition of the data packet is changed based on the analysis information and transmitted to the management server, so that a large amount of vibration data can be transmitted to the management server via low-speed wireless communication.

[0015] According to an embodiment of the present invention, vibration data measured from a rotating device is sent to a remote location, and unnecessary power waste caused by sampling vibration signals of the same period is prevented by adjusting the sampling rate frequency according to time periods with less noise and time periods with more noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a diagram showing the configuration of a vibration sensor data transmission amount reduction system using frequency conversion according to the first embodiment.

[0017] Figure 2 It is a block diagram showing the detailed structure of the sensor data transmission amount reduction device.

[0018] Figure 3 : is a diagram showing an analysis example of the frequency structure of the detection signal of the vibration sensor.

[0019] Figure 4 It is a diagram showing the structure of a data packet.

[0020] Figure 5 1 is a diagram showing that a detection signal of a vibration sensor is divided into a plurality of time domains having similarities by a waveform analysis unit.

[0021] Description of Reference Numerals

[0022] 100: reducing device; 110: signal processor; 120: frequency analyzing unit; 130: waveform analyzing unit; 140: packet generating unit; 150: sending unit; 200: management server. DETAILED DESCRIPTION

[0023] Several embodiments of the present invention will be described in detail below using the accompanying drawings. However, it should be understood that this is not intended to limit the present invention to any specific embodiment, and all deformations, equivalents and substitutions of the technical concept of the present invention are included in the scope of the present invention.

[0024] In this specification, an expression in a singular form includes an expression in a plural form unless the context clearly dictates otherwise.

[0025] In the present specification, unless explicitly described to the contrary, when a certain component is described as “having” or “comprises” a certain subcomponent, it means that other components are not excluded but other components may be further included.

[0026] In this specification, the terms "unit", "module" and "component" refer to a unit that processes at least one function or operation and can be implemented by hardware, software or a combination of hardware and software.

[0027] In this specification, the word "connected" may refer to two components being directly connected, but is not limited to this and may also mean being connected via one or more other components placed between the components.

[0028] Figure 1 1 is a block diagram of a vibration sensor data transmission amount reduction system using frequency conversion according to the first embodiment.

[0029] like Figure 1 As shown, the vibration sensor data transmission amount reduction system includes a data transmission amount reduction device 100 and a management server 200 .

[0030] The reduction device 100 sends a packet containing data after Fourier transform of the detection signal to the management server 200. According to the composition of the frequencies analyzed in the data after Fourier transform, the data packet is constituted as a single packet or a continuous packet and sent to the management server 200. The detection signal is received from a vibration sensor arranged on a rotating body.

[0031] In this specification, a rotating body refers to a rotating device such as a steam turbine or a gas turbine operating in a power plant, or a rotating member based on a rotor such as a wind turbine, a thrust propeller, an air screw, or the like.

[0032] The vibration sensor may be directly disposed on the rotating body as described above, or may be indirectly disposed in an equipment room that accommodates the rotating body. For example, when the rotating body is a turbine, the vibration sensor may be disposed on the outer peripheral surface of the turbine blades, or may be indirectly disposed on the inner side surface of the equipment room surrounding the turbine.

[0033] The supervisory server 200 detects an abnormal state of the rotating body by analyzing the sensor information collected from the reducing device 100 .

[0034] The detection of abnormal conditions refers to finding signal individuals in the data that present different patterns from the expected ones. The deformation patterns of such data can predict the appearance of cracks on the blades, the bending of the blades due to external factors, or the presence of foreign matter on the outside of the blades.

[0035] Below, refer to Figure 2 , the detailed structure of the sensor data transmission amount reduction device 100 is described in detail.

[0036] Figure 2 2 is a block diagram showing a detailed configuration of the sensor data transmission amount reducing device 100 .

[0037] like Figure 2 As shown, the reducing device 100 includes: a signal processor 110 , a frequency analyzing unit 120 , a packet generating unit 140 , and a transmitting unit 150 . In addition, the reducing device 100 may further include a waveform analyzing unit 130 .

[0038] The signal processor 110 converts the detection signal of the vibration sensor disposed on the rotating body into a digital detection signal. For example, when the rotating body is a turbine, the analog vibration signal generated when the blade rotates is converted into a digital detection signal.

[0039] The signal processor 110 converts the converted vibration digital detection signal from the time domain into the frequency domain. At this time, the signal processor 110 can convert the detection signal in the time domain into the frequency domain through Fourier Transform or Fast Fourier Transform.

[0040] The frequency analysis unit 120 (frequency analyzer) analyzes the frequency structure included in the detection signal in the frequency domain converted by the signal processor 110 .

[0041] The composition of the frequencies contained in the digital detection signal in the frequency domain may refer to separating the frequencies having different intensities (Hz) from each other converted from the vibration signal generated by the rotating body, and confirming the number of each separated frequency. If there are three frequencies having different intensities (Hz), the digital detection signal in the corresponding frequency domain contains three vibration signals.

[0042] For example, the frequencies generated by direct causes of the blades may have different frequency intensities (hz), such as the frequencies generated when the blades rotate, the frequencies generated by cracks on the blades, the frequencies generated when the blades bend due to external factors, and the frequencies generated when foreign matter is attached to the surface of the blades.

[0043] In addition, when a rotating body is driven in a factory having various equipment, the frequencies generated by the operation of other equipment in the surrounding area, or when a wind turbine is installed at a location near a road, the frequencies generated by indirect causes in the surrounding area such as vibration signals from vehicles passing by in the surrounding area may also have different frequency intensities (Hz).

[0044] The packet generator 140 constructs the digital detection signal in the frequency domain into a data packet including a header and a payload.

[0045] At this time, based on the configuration of the frequency analyzed by the frequency analyzing unit 120 , the packet generating unit 140 configures the packets as either a single packet consisting of one packet or a continuous packet consisting of a plurality of packets.

[0046] For example, when the frequency structure is a single frequency, the packet generation unit 140 may form the frequency domain digital detection signal into a single packet. Also, when the frequency structure includes multiple frequencies, the packet generation unit 140 may form the frequency domain digital detection signal into continuous packets.

[0047] The packet generation unit 140 may generate a header of a data packet, and the header of the data packet may be configured to include: a packet flag for distinguishing a single packet, a continuous packet start, a continuous packet continuation, and a continuous packet end; a measurement time (sensing time) of a vibration sensor; and a unit payload size. For reference, the header may also include a communication protocol and an ID of a vibration sensor (when there are multiple rotating bodies, the vibration signal of each target object is detected).

[0048] The packet generation unit 140 may construct a payload of the data packet as a unit payload of information contained in each digital detection signal (ie, frequency) in the frequency domain.

[0049] For example, when the frequency is configured as a single frequency, the packet generation unit 140 designates the packet flag as a single packet, and configures the single frequency information to be included in one unit payload.

[0050] Furthermore, when the frequency structure is a plurality of frequencies, the packet generation unit 140 separates the plurality of frequencies, and the packet flag is designated as any one of a continuous packet start, a continuous packet continuation, and a continuous packet end according to the order of the separated frequencies. Furthermore, the packet generation unit 140 structures the information of the separated frequencies to be included in each of the plurality of unit payloads. If there are three separated frequencies, the unit payload may be composed of three.

[0051] For reference, the measurement time (sensing time) included in the header of the data packet is used to confirm the complexity of the signal at the time measured from the vibration sensor. When the management server 200 receiving the data packet analyzes the digital detection signal included in the data packet through inverse Fourier transform (Inverse FT) or fast inverse Fourier transform (Inverse FFT), other integration techniques can be applied according to the measurement time to detect abnormal values ​​of the rotating body. This description will be described again below.

[0052] The sending unit 150 transmits the data packet generated by the packet generating unit 140 to the management server 200 .

[0053] The transmitting unit 150 may support long-distance communication, such as low power wide area communication (LPWA). In addition, the transmitting unit 150 may also support mobile communication protocols such as 2G, 3G, 4G, 5G, or wireless broadband (Wireless broadband, Wibro), World Interoperability for Microwave Access (World Interoperability for Microwave Access, Wimax), High Speed ​​Downlink Packet Access (High Speed ​​Downlink Packet Access, HSDPA), etc.

[0054] The waveform analysis unit 130 (waveform analyzer) accumulatively stores the detection signal of the vibration sensor, and analyzes the change of the waveform of the detection signal according to time in units of days, and distinguishes it into a plurality of time domains having signal similarity within a set standard.

[0055] The time domain may refer to n time units (n is a positive real number), and a day may be roughly divided into two to distinguish between a daytime time domain and a nighttime time domain, or may be divided into a commuting time domain, a daytime working time domain, and a nighttime time domain. However, this is only an example, and as long as it is a time domain with signal similarity within a preset standard, a day may be divided into m (m is a positive integer) detailed time domains.

[0056] As a specific example, assume that a vibration sensor detects vibrations of rotating equipment (i.e., rotating bodies) in a factory with various mechanical equipment. Some of the mechanical equipment in the factory will continue to operate 24 hours a day regardless of whether employees are present, while some of the equipment can only operate when employees are working.

[0057] In this case, since the machine starts running during the operation time of the factory machinery (07:00 to 09:30 am), the vibration signal generated by the machine during the initial operation (e.g., engine start-up vibration) is mixed in with the noise. Therefore, in this time domain, the detection signal will show considerable complexity (or signal changes).

[0058] During the daytime working hours (09:31 am to 04:30 pm), the noise of the mechanical equipment during initial operation is relatively low, and the mechanical equipment continues to operate, so the complexity of the detection signal (or the change of the signal) is relatively low compared with the operating domain of the factory mechanical equipment.

[0059] During the off-get off work time from 04:31 pm to 06:59 am the next day when some mechanical equipment is stopped, some mechanical equipment is not in operation, and thus has the lowest signal complexity (or signal change) compared with the operation time domain of factory mechanical equipment and the daytime working time domain.

[0060] Therefore, the waveform analysis unit 130 analyzes the accumulated detection signals of the rotating equipment in the factory on a daily basis, and can roughly confirm that the complexity characteristics of the detection signals in the operating time domain of the mechanical equipment, the daytime working time domain, and the off-duty time domain when some mechanical equipment is terminated remain similar. Therefore, the waveform analysis unit 130 divides a day of the factory's rotating equipment into three time domains.

[0061] The above assumption is that the characteristics of the time domain can be normally predicted. Even in a factory, the characteristics of the detection signal measured in each detailed area may vary greatly in each time domain.

[0062] Therefore, the waveform analysis unit 130 analyzes the sensor information accumulated and stored by the vibration sensor at a specific position during a preset period (a month, a quarter, or half a year, etc.), analyzes the change of the waveform of the detection signal according to time in units of days, and divides the time domains with signal similarity within the set standard into several. The time domains divided by the waveform analysis unit 130 can be automatically changed through periodic analysis.

[0063] At this time, the signal processor 110 may differently set the sampling rate for digital conversion according to each time domain distinguished by the waveform analysis unit 130 .

[0064] For example, in the time domain where the detection signal of the vibration sensor has relatively little change, the digital signal can be easily restored to an analog vibration signal even if the sampling rate is reduced, so the signal processor 110 can reduce the sampling rate for digital conversion.

[0065] Furthermore, in the time domain where the detection signal of the vibration sensor changes relatively more, if the sampling rate is reduced, it is difficult to restore the digital signal to an analog vibration signal or an error exceeding the standard value range may occur, so the signal processor 110 can increase the sampling rate.

[0066] Therefore, the signal processor 110 can prevent unnecessary power waste caused by sampling vibration signals of the same period by adjusting the sampling rate according to multiple time domains.

[0067] On the other hand, when the waveform analysis unit 130 notifies that the detection signal of the vibration sensor has not changed during the preset time, the packet generation unit 140 may interrupt further generation of the packet after specifying the packet transmission interruption (halt) in the packet flag. The fact that the detection signal of the vibration sensor has not changed during the preset time may mean that the waveform of the detection signal measured from the rotating body may be in a state of having a regular shape, or may be in a state where the driving of the rotating body has ended, or may be a state where the detection signal does not need to be measured due to a specified reason although the rotating body is being driven.

[0068] When the reduction device 100 does not notify the management server 200 of the interruption of packet transmission, it is difficult for the management server 200 to confirm whether the interruption of packet transmission is caused by a communication failure or other reasons, so this is to notify the management server 200.

[0069] Also, when the waveform analysis unit 130 notifies that a change in the waveform exceeding a preset standard occurs in the detection signal of the vibration sensor, the packet generation unit 140 may restart the generation of the packet.

[0070] Figure 3 : is a diagram showing an analysis example of the frequency structure of the detection signal of the vibration sensor.

[0071] Figure 3 (a) shows the case where the frequency structure to be analyzed is a single frequency. Figure 3 (b) shows a case where the analyzed frequency structure consists of multiple frequencies.

[0072] Specifically, the signal processor 110 converts a time domain of a detection signal of a vibration sensor provided on a rotating body into a frequency domain.

[0073] The frequency analysis unit 120 analyzes the configuration of frequencies included in the detection signal in the frequency domain converted by the signal processor 110 .

[0074] The composition of frequencies included in the detection signal in the frequency domain may also refer to the number of frequencies having different intensities (hz) from each other converted from the vibration signal generated by the rotating body.

[0075] For example, the frequencies generated by direct causes of the blades may have different frequency intensities (hz), such as the frequencies generated when the blades rotate, the frequencies generated by cracks on the blades, the frequencies generated when the blades bend due to external factors, and the frequencies generated when foreign matter is attached to the surface of the blades.

[0076] like Figure 3 As shown in (b), multiple frequencies can be analyzed in this case.

[0077] In addition, when a rotating body is driven in a factory having various equipment, the frequencies generated by the operation of other equipment in the surrounding area, or when a wind turbine is installed at a location near a road, the frequencies generated by indirect causes in the surrounding area such as vibration signals from vehicles passing by in the surrounding area may also have different frequency intensities (Hz).

[0078] like Figure 3 As shown in (b), multiple frequencies can also be analyzed in this case.

[0079] Figure 4 It is a diagram showing the structure of a data packet.

[0080] like Figure 4 As shown, the data packet including the frequency-domain digital detection signal generated by the packet generation unit 140 is constructed by combining a header and a payload.

[0081] The header includes a packet flag, a measurement time, and a unit payload size, and the payload includes at least one unit payload.

[0082] The packet flag distinguishes a single packet, a continuous packet start, a continuous packet continuation, and a continuous packet end. For example, when the frequency structure is a single frequency, the packet generation unit 140 specifies the packet flag as a single packet, and when the frequency structure is a plurality of frequencies, the packet flag is specified as any one of the continuous packet start, the continuous packet continuation, and the continuous packet end according to the order of the frequencies separated by the plurality of frequencies.

[0083] For reference, a packet flag may be designated as 0 for a single packet, and a packet start may be designated as 1 for consecutive packets, a consecutive packet continuation may be designated as 2, and a consecutive packet end may be designated as 3. Each item of the packet flag may be 2 bits to 1 byte.

[0084] The measurement time determines to which of the above-mentioned time domains the detection time of the vibration sensor belongs.

[0085] The measurement time is used to confirm the degree of signal complexity of the time measured from the vibration sensor. When the management server 200 that receives the data packet analyzes the digital detection signal contained in the data packet through inverse Fourier transform (Inverse FT), other integration technologies can be applied according to the measurement time to detect abnormal values ​​of the rotating body.

[0086] The size of the unit payload includes size information of each unit payload or size information of the entire unit payload. For reference, the size of the unit payload may be length information of the unit payload.

[0087] The unit payload contains the digital detection signal in the frequency domain. The number of unit payloads can vary depending on the composition of the frequencies being analyzed.

[0088] The digital detection signal in the frequency domain contained in the unit payload may be analyzed in the management server 200 by inverse Fourier transform (Inverse FT).

[0089] Figure 5 2 is a diagram showing that the detection signal of the vibration sensor is divided into a plurality of time domains having similarities by the waveform analysis unit 130 .

[0090] like Figure 5 As shown, the waveform analysis unit 130 accumulatively stores the detection signal of the vibration sensor, and analyzes the change of the waveform of the detection signal according to time in units of days, and distinguishes it into a plurality of time domains having signal similarity within a set standard.

[0091] As a specific example, since the machine starts running during the operation time of the factory machinery and equipment (07:00 am to 09:30 am), the vibration signal (e.g., engine start-up vibration) generated by the machine during the initial operation will be mixed in the noise. Therefore, in this time domain, the detection signal will show considerable complexity (or signal changes), which is distinguished as the first time domain T1.

[0092] During the daytime working hours (09:31 am to 04:30 pm), the noise of other mechanical equipment during initial operation is relatively low, and the mechanical equipment continues to operate, so the complexity of the detection signal (or the change of the signal) is relatively low compared with the operating domain of the factory mechanical equipment, which is distinguished as the second time domain T2.

[0093] During the period from 04:31 p.m. to 06:59 a.m. the next day when some mechanical equipment is no longer in operation, some mechanical equipment is not in operation. Therefore, compared with the operation domain and daytime working domain of factory mechanical equipment, it has the lowest signal complexity (or signal change), which is distinguished as the third time domain T3.

[0094] In the first time domain T1 where the signal changes most complexly, the packet generation unit 140 can be composed of continuous packets, and the unit payload can also be constructed to be the same as the number of frequencies. In addition, the signal processor 110 can set the sampling rate of the first time domain T1 to be higher than the third time domain T3 where the signal changes least.

[0095] Furthermore, the third time domain T3 where the signal change is the smallest may also consist of only one analyzed frequency, and when the analyzed frequency is one, the packet generation unit 140 may construct the digital detection signal of the corresponding frequency domain into a single packet.

[0096] For reference, in the third time domain T3 where the signal variation is the smallest, even if there is a configuration of a plurality of frequencies, the data packet may be configured by a single packet, and the unit payload may be configured by a number corresponding to the number of frequencies.

[0097] The above description is made with reference to several embodiments of the present invention. It will be easily understood by those skilled in the art who have common knowledge in this technical field that various modifications and changes may be made to the present invention without departing from the scope of the idea and field of the present invention as described in the attached claims.

[0098] In addition, some functions of the above-mentioned device or system are implemented in a practical manner by a program of instructions for implementing the function, so as to be included in a computer-readable recording medium and provided. The computer-readable recording medium may include a separate program instruction, a data file, a data structure, etc., or a combination thereof. Examples of the computer-readable recording medium include: magnetic media (e.g., hard disk, floppy disk, and tape); optical recording media (e.g., CD-ROM, DVD); magneto-optical media (e.g., magneto-optical floptical disk); and hardware devices specially configured to store and execute program instructions (e.g., read-only memory ROM, random access memory RAM, flash memory, universal serial bus USB memory, etc.).

[0099] This invention was supported by the following Korean national research and development program.

[0100] Project number: 2023020401

[0101] Project number: 202302-0401

[0102] Department Name: Ministry of Environment

[0103] Name of the project management (specialized) agency: Korea Environment Corporation (Korean Water Cluster)

[0104] Research project name: Water technology proactive digital support project

[0105] Research topic name: Intelligent control valve system

[0106] Contribution rate: 1 / 1

[0107] Project implementation agency: Yier Technology Co., Ltd.

[0108] Research period: 2023.03.24~2023.12.31.

Claims

1. A sensor data transmission amount reduction device using frequency conversion, characterized in that: include: a signal processor, which converts the detection signal of the vibration sensor disposed on the rotating body into a digital detection signal, and converts the digital detection signal from the time domain into the frequency domain, A frequency analysis unit analyzes the composition of frequencies contained in the digital detection signal in the frequency domain, a packet generating unit that forms the digital detection signal in the frequency domain into a data packet that combines a header and a payload, and forms any one of a single packet consisting of one packet or a continuous packet consisting of a plurality of packets based on the analyzed frequency composition, and The sending unit transmits the generated data packet to the management server.

2. The sensor data transmission amount reduction device using frequency conversion according to claim 1, characterized in that: The header of the data packet includes: Packet flags distinguish between a single packet, the start of a continuous packet, the continuation of a continuous packet, and the end of a continuous packet. The measurement time of the vibration sensor, and The size of the unit payload.

3. The sensor data transmission amount reduction device using frequency conversion according to claim 2, characterized in that: In the packet generation unit, When the digital detection signal includes a single frequency, the packet flag is designated as a single packet, and information of the single frequency is constructed as the unit payload, When the digital detection signal includes a plurality of frequencies, the packet generation unit separates the plurality of frequencies, the packet flag is designated as any one of a continuous packet start, a continuous packet continuation, and a continuous packet end according to the order of the separated frequencies, and the information of the separated frequencies is constituted as the unit payload.

4. The sensor data transmission amount reduction device using frequency conversion according to claim 1, characterized in that: Also includes: a waveform analysis unit that accumulates and stores the detection signal of the vibration sensor, analyzes the change of the waveform of the detection signal according to time in units of days, and distinguishes the change of the waveform into a plurality of time domains having signal similarity within a set standard, In the signal processor, In a time domain where the detection signal of the vibration sensor changes relatively less, the sampling rate for digital conversion is reduced, and in a time domain where the detection signal of the vibration sensor changes relatively more, the sampling rate is increased.

5. The sensor data transmission amount reduction device using frequency conversion according to claim 4, characterized in that: In the packet generation unit, When the waveform analysis unit notifies that the detection signal of the vibration sensor has not changed during a preset time, the packet generation unit interrupts further generation of packets after specifying interruption of packet transmission in the packet flag, When the waveform analysis unit notifies that a change exceeding a preset standard waveform occurs in the detection signal of the vibration sensor, the packet generation unit restarts packet generation.

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