How to read an analog meter

Abstract

To provide a simplified reading method for a plurality of analog meters installed in a facility.SOLUTION: A method includes the steps of: detecting, by a computation process, scale markings indicated on an analog meter, position of an indicator, and a center position of the analog meter from imaging data obtained by imaging the analog meter; identifying first scale markings and second scale markings located in positions interposing the indicator; calculating a ratio k between a first angle θ and a second angle φ, the first angle being formed by a first straight line connecting the center position of the analog meter and a substantial center position of the first scale markings or a corresponding scale position, and a second straight line connecting the center position of the analog meter and a substantial center position of the second scale markings or a corresponding scale position, the second angle being formed by a third straight line connecting the indicator and the center position of the analog meter and the first or second straight line; and determining a value read from the indicator on the basis of a value obtained by prorating a difference between the first scale markings and the second scale markings by the ratio k.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for reading an analog meter, and more particularly to a method for reading a plurality of analog meters installed in a facility. [Background technology]

[0002] A large number of meters are typically installed in electrical stations such as substations, switchyards, power plants, etc. These meters are installed to measure different physical quantities such as voltage, current, frequency, temperature, etc.

[0003] These meters often use analog meters and most of them do not have digital output terminals, which means that workers must read the meters during maintenance and inspection.

[0004] Patent document 1 discloses a technology in which a reading device including a camera is installed for each of a number of analog meters, and the reading device reads the meter based on data automatically captured by the camera and transmits the results to a central unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-075848 A Summary of the Invention [Problem to be solved by the invention]

[0006] The analog meter reading system 1 disclosed in Patent Document 1 includes a reading device provided for each of a plurality of analog meters, and a central device that collects meter reading data transmitted from the reading devices. Each reading device disposed corresponding to each meter includes an imaging unit for capturing an image of the analog meter, and a microcomputer for image processing the two-dimensional image data captured by the imaging unit.

[0007] The reading device is equipped with a storage means such as a ROM or RAM, and a virtual arc line centered on the center of rotation around which the needle of each analog meter rotates is set in advance in this storage means. Specifically, the virtual line is specified by inputting the radius from the center of rotation of the needle and the start and end points of the measurement range. The reading device then reads information about the virtual line from the storage means, and detects information about pixel positions extracted from the captured image data, and information about the correspondence between the positions of the extracted pixels and the indicated value on the dial.

[0008] In other words, according to the method described in Patent Document 1, a process is required to input information for identifying a virtual line in advance for each meter.

[0009] The method described in Patent Document 1 is considered to be effective when the types of analog meters are limited. This is because the information on the virtual line for each meter is often common. Specifically, the method disclosed in Patent Document 1 is effective when applied to an analog meter installed on the electricity consumer's side for the purpose of measuring the amount of power consumption, for example, when the meter is analog.

[0010] However, meters installed in electric power stations such as substations, switching yards, and power plants have a wider variety of meter types because there are a wider variety of physical quantities that need to be measured compared to watt-hour meters installed on the electricity consumer side. Furthermore, many meters are installed in electric power stations such as substations, switching yards, and power plants.

[0011] From this perspective, it is not realistic to install a camera-equipped reading device as described in Patent Document 1 for each of the many meters installed in electric power stations such as substations, switching stations, and power stations, since it would require inputting setting values ​​for each meter. In addition, some electric power stations are located in mountainous areas, and there are many places where communication waves cannot reach and the Internet cannot be connected. For this reason, as described in Patent Document 1, there may be cases where data read by the reading device cannot be transmitted to the central unit.

[0012] On the other hand, a wide variety of analog meters are installed in the above-mentioned electric power station, and in some cases, they are installed at locations where workers can pass through and are difficult to visually check from a normal position due to the angle. When inspecting an electric power station, it is necessary to read the indicated values ​​of these multiple meters and record them for reporting. If this reading work is done visually, it cannot be denied that there is a possibility that the read values ​​will vary depending on the experience of the workers. In addition, the work of reading each analog meter manually is a burden.

[0013] In view of the above problems, an object of the present invention is to provide a method for simplifying the work of reading a plurality of analog meters installed in a facility such as an electric power station. [Means for solving the problem]

[0014] The present invention provides a method for reading a plurality of analog meters installed in a facility, the method comprising the steps of: A step (a) of capturing an image of the analog meter to be read by an imaging unit to obtain imaging data; (b) inputting the imaging data to a processing unit mounted in the same device as the imaging unit, or mounted in a device separate from the imaging unit and installed within or near the site of the facility, via a storage medium or via a wired or wireless non-internet communication line; (c) detecting, by the arithmetic processing unit, the scale numbers displayed on the analog meter, the position of the pointer, and the center position of the analog meter from the imaging data through arithmetic processing; a step (d) in which the calculation processing unit identifies a first scale number and a second scale number that is greater in value than the first scale number and that are located adjacent to the pointer detected in the step (c); a step (e) in which the arithmetic processing unit calculates a first angle θ formed by a first line connecting the substantial center position of the first scale numeral or the scale position corresponding to the first scale numeral and the center position of the analog meter, and a second line connecting the substantial center position of the second scale numeral or the scale position corresponding to the second scale numeral and the center position of the analog meter, and a ratio k of a second angle φ formed by a third line connecting the pointer and the center position of the analog meter and the first line or the second line; and (f) a step in which the calculation processing unit determines a reading of the pointer based on a value obtained by proportionally allocating the difference between the first scale number and the second scale number at the ratio k, The steps (a) to (f) are performed for each of the plurality of analog meters.

[0015] According to the above method, the image data of the analog meter is sent to a calculation processor, which performs calculations to identify the numbers (first and second scale numbers) on the scale adjacent to the pointer and the distance between the pair of scale numbers that the pointer is pointing to. Then, based on the identified information, the indicated value of the pointer is determined by proportional distribution. Typically, the numbers on the scales that sandwich the pointer are used as the numbers on the scale adjacent to the pointer.

[0016] A known object detection algorithm can be used as a method for reading the scale numbers from the image data by the calculation processing unit. Examples of algorithms that can be used include YOLO, R-CNN, SSD, and the like.

[0017] According to the above method, the indicated value of an analog meter can be read by reading the numbers of a pair of scales adjacent to a pointer from the image data and performing a simple calculation such as proportional distribution based on the relative positional relationship between the position corresponding to the numbers of the pair of scales and the position of the pointer. Therefore, initial settings, etc. for each meter are not required. In other words, there is no need to read information related to the initial settings from a central device, and it is possible to read meters installed in facilities that do not have an Internet communication environment.

[0018] Some analog meters have evenly spaced scale numbers, while others have unevenly spaced scale numbers. With the above method, it is possible to read the indicated value on either the former or the latter analog meter.

[0019] The pointer of an analog meter has a certain thickness. Therefore, it is expected that the scale number and the pointer will partially overlap. In this case, the calculation unit may recognize the numbers before and after the scale number that the pointer partially overlaps, and perform a process to estimate the scale number that the pointer partially overlaps. For example, even if the scale number cannot be read by a known object detection algorithm alone because the pointer partially overlaps with the scale number, if the scale numbers before and after it can be recognized as "3" and "5", the calculation processing unit may estimate that the scale number that the pointer partially overlaps is "4".

[0020] Furthermore, according to the above method, it is not necessary to install a camera for capturing images and a device for performing calculations for each meter in advance. In other words, the reading work can be performed by having an operator go to the installation location of each analog meter, capture an image of the analog meter, and output or transmit the captured image data to the calculation processing unit.

[0021] Specifically, a device (computer) for performing arithmetic processing may be installed at a predetermined location within the premises of the facility or near the premises of the facility, and image data of each analog meter captured by an operator may be input to this device via wired or short-range communication such as wireless LAN, Bluetooth (registered trademark) or infrared.As another example, image data of each analog meter captured by an operator may be recorded on an external storage medium such as a memory card, and the external storage medium may be attached to the computer, allowing the data to be input to a processing unit mounted on the computer.

[0022] As yet another example, a worker carrying a terminal device such as a smartphone or tablet computer equipped with an imaging unit may go to the location where each analog meter is installed, photograph the analog meter, and the obtained imaging data may be output to a calculation processing unit within the terminal device.

[0023] In other words, according to the above method, the initial cost required for implementation can be significantly reduced compared to the method of Patent Document 1. This method is particularly suitable for reading analog meters installed in electrical stations such as substations, switchyards, and power plants.

[0024] Furthermore, according to the above method, the calculation processing unit reads the indicated value of the needle by calculation processing based on the image data of the analog meter, so that reading errors by the operator can be minimized.

[0025] The step (a) may be a step in which an operator moves the analog meter to be read to a position where an image of the analog meter can be captured, and captures an image of the analog meter using a device equipped with the imaging unit.

[0026] According to the above method, the actual work performed by each worker is essentially just to capture the images of each analog meter with the imaging unit, and other processing is performed by the calculation processing unit. As a result, the workload of the worker can be significantly reduced compared to the conventional method in which the worker visually reads the indicated values ​​of each analog meter.

[0027] The method for reading an analog meter includes a step (g) of outputting the imaging data of the analog meter obtained in the step (a) and information related to the needle reading value obtained in the step (f) to an output unit, Step (g) may be performed for each of the plurality of analog meters.

[0028] As mentioned above, periodic inspections and tests are required in electrical stations such as substations, switching yards, and power plants. During such inspections and tests, it is necessary to record the readings of the analog meter. According to the above method, the image data of the analog meter is output together with the readings, so by recording both of them, it is expected that the evidential capability of the readings can be improved.

[0029] In particular, in the above method, the indicated value of the analog meter is read using image data of the analog meter. In other words, when the above method is executed to read the analog meter, image data of the analog meter is always obtained. In other words, there is no need to separately image the analog meter just to leave evidence, and the image data of the analog meter that has already been obtained can be effectively used.

[0030] The analog meter to be read in the step (a) may have uneven scale intervals.

[0031] As a specific example, the step (e) is a step of calculating, by the calculation processing unit, a ratio k of a second angle φ between the third straight line and the first straight line to the first angle θ, The step (f) may be a step in which the calculation processing unit adds the value of the first scale number to a value obtained by proportionally allocating the difference between the first scale number and the second scale number at the ratio k, and determines the result as the reading of the pointer.

[0032] As another specific example, the step (e) is a step of calculating, by the calculation processing unit, a ratio k of a second angle φ between the third straight line and the second straight line to the first angle θ, The step (f) may be a step in which the calculation processing unit subtracts a value obtained by proportionally allocating the difference between the first scale number and the second scale number at the ratio k from the value of the second scale number to determine the value as the reading of the pointer. Effect of the Invention

[0033] According to the present invention, the work of reading a plurality of analog meters installed in a facility such as an electric power station can be simplified. [Brief description of the drawings]

[0034] [Figure 1] 2 is a flowchart showing an example of a procedure for carrying out an embodiment of a method for reading an analog meter according to the present invention; [Diagram 2] 1 is an example of a block diagram showing a schematic diagram of a system configuration when an embodiment of a method for reading an analog meter according to the present invention is executed; [Diagram 3] 1 is a schematic diagram for explaining image recognition performed by a calculation processing unit, in which explanatory symbols and the like are attached to a captured image of an analog meter. [Figure 4] 1 is a schematic diagram for explaining an example of a method for reading an indication value of an analog meter, which is performed by an arithmetic processing unit, in which explanatory symbols and the like are added to a captured image of the analog meter. [Diagram 5] 1 is a schematic diagram for explaining an example of a method for reading an indication value of an analog meter, which is performed by an arithmetic processing unit, in which explanatory symbols and the like are added to a captured image of the analog meter. [Figure 6] 1 is a schematic diagram for explaining an example of a method for reading an indication value of an analog meter, which is performed by an arithmetic processing unit, in which explanatory symbols and the like are added to a captured image of the analog meter. [Figure 7]FIG. 13 is a diagram showing a schematic example of an embodiment in which a read result is output to an output unit, and an imaging unit is also shown. [Figure 8] FIG. 13 is a diagram showing a schematic example of an embodiment in which a read result is output to an output unit, and an imaging unit is also shown. [Figure 9] FIG. 13 is a diagram showing a schematic example of an embodiment in which a read result is output to an output unit, and an imaging unit is also shown. [Figure 10] FIG. 1 is an example of a block diagram showing a schematic diagram of a system configuration when an embodiment of a method for reading an analog meter according to the present invention is executed, and an image at the time of photographing is also shown. [Figure 11] 13 is an example of a screen for selecting an inspection item. [Figure 12] 13 is an example of a display screen when an analog meter is photographed. [Figure 13] 10 is a diagram illustrating an example of a mode in which a read result is output to an output unit. [Figure 14] FIG. 1 is an example of a block diagram showing a schematic diagram of a system configuration when an embodiment of a method for reading an analog meter according to the present invention is executed, and an image at the time of photographing is also shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] An embodiment of a method for reading an analog meter according to the present invention will be described with reference to the accompanying drawings. Fig. 1 is a flow chart showing a typical procedure for carrying out the method for reading an analog meter according to the present invention. In the following description, the step numbers in Fig. 1 will be referred to as appropriate.

[0036] Fig. 2 is a block diagram showing a schematic system configuration when the reading method of the present embodiment is executed. In the example of Fig. 2, it is assumed that a plurality of analog meters 2, 2, ... are installed in a facility 1 such as an electric power station. When the reading method of the present embodiment is executed, an imaging unit 11 and a calculation processing device 20 are used. However, as will be described later, it is also possible to use a calculation processing device 20 equipped with the functions of the imaging unit 11.

[0037] (Step #1: Set the imaging unit in a position where it can capture the meter image) Of the multiple analog meters 2, 2, . . . installed in the facility 1, the imaging unit 11 is set at a position where it can image one analog meter 2a to be read.

[0038] As an example, a worker holding the imaging unit 11 may move the imaging unit 11 to a position where the analog meter 2a can be imaged, and hold the imaging unit 11 with the imaging direction facing the analog meter 2a. In this case, the imaging unit 11 may be a digital camera, or a smartphone, tablet computer, or notebook computer equipped with a camera function.

[0039] As another example, a digital camera may be set in advance at a position where it can capture an image of the analog meter 2a. In this case, it is preferable that the digital camera be remotely activated from another location in the facility 1 so that the analog meter 2a can be captured.

[0040] The imaging direction is preferably perpendicular to the display surface of the analog meter 2a, but as described below, it may be oblique to the display surface as long as the scale numbers, pointer, and center position of the analog meter 2a can be imaged.

[0041] (Step #2: Take a picture of the analog meter) The analog meter 2a is imaged by the imaging unit 11 set in step #1. This step #2 corresponds to the process (a).

[0042] (Step #3: Input the image data into the processor) As shown in FIG. 2, the arithmetic processing device 20 includes an input receiving unit 21, an arithmetic processing unit 22, a storage unit 23, and an output unit 24. The input receiving unit 21 is an input interface that receives data input from outside the arithmetic processing device 20 and converts the data into a form that can be used within the arithmetic processing device 20 as necessary. The arithmetic processing unit 22 is a functional means that performs a predetermined arithmetic processing on the data, and is, for example, a processor such as a CPU or MPU. The storage unit 23 is a storage medium such as a hard disk or memory, and temporarily holds data received by the input receiving unit 21 and records a calculation program to be executed by the arithmetic processing unit 22 as necessary. However, the calculation program may be recorded within the arithmetic processing unit 22. The output unit 24 is an interface for outputting the calculation result performed by the arithmetic processing unit 22. As an output method, a method of displaying on a screen or a method of transmitting / outputting data to an external device (computer, printer, etc.) can be adopted.

[0043] 2, the arithmetic processing unit 22 is provided in the arithmetic processing device 20, which is a device separate from the imaging unit 11. For this reason, imaging data d1 captured by the imaging unit 11 is input to the arithmetic processing unit 22 via the input receiving unit 21 of the arithmetic processing device 20 by any method.

[0044] As one example, the imaging unit 11 and the arithmetic processing device 20 may be connected by a known signal line such as a USB cable or a LAN cable, and the imaging data d1 may be sent from the imaging unit 11 to the arithmetic processing device 20 via this wire. As another example, if an external storage medium such as an SD card or a memory stick is installed in the imaging unit 11, the imaging data d1 may be recorded in this external storage medium, and the imaging data d1 may be input to the arithmetic processing device 20 by attaching this external storage medium to the arithmetic processing device 20.

[0045] As another example, the imaging unit 11 and the arithmetic processing device 20 may be connected via a short-distance wireless communication line such as Bluetooth (registered trademark) or a wireless LAN in the facility 1, and the imaging data may be sent from the imaging unit 11 to the arithmetic processing device 20 via this wireless communication. If the facility 1 is an electric power station such as a substation, a switchyard, or a power plant, the facility 1 may not have Internet communication in some locations. However, since both the imaging unit 11 and the arithmetic processing device 20 are installed in the facility 1, an environment for wireless communication between the two may be established. In this case, the imaging unit 11 and the arithmetic processing device 20 only need to be able to wirelessly communicate with each other in a closed environment in the facility 1, so that even in an environment where they cannot be connected to an Internet line, the imaging unit 11 and the arithmetic processing device 20 can wirelessly transmit and receive the imaging data d1 between them. In other words, an Internet connection is not essential when executing the reading method of this embodiment.

[0046] This step #3 corresponds to process (b).

[0047] (Step #4: Image recognition of imaging data) The calculation processing unit 22 performs image recognition processing on the input image data d1. In detail, a known object detection algorithm is used to recognize the scale numbers displayed on the analog meter 2a, the position of the pointer, and the center position of the analog meter 2a. As an example of the object detection algorithm, YOLO, R-CNN, SSD, etc. can be used. Among these, YOLO, which is particularly excellent in number recognition, can be preferably used. A program related to this algorithm may be pre-recorded in the calculation processing unit 22 or the storage unit 23.

[0048] FIG. 3 is a schematic diagram for explaining the image recognition performed by the arithmetic processing unit 22, in which explanatory symbols and the like are added to the captured image of the analog meter 2a.

[0049] In general, analog meters 2, 2, ... are provided with a scale for reading the pointer and multiple scale numbers displayed at a predetermined (even / uneven) interval. The analog meter 2 shown in Fig. 3 has eight types of scale numbers, "0", "1", "2", "3", "4", "5", "10", and "15", and multiple scales are provided at locations corresponding to these scale numbers and multiple locations connecting them. The analog meter 2 shown in Fig. 3 also has multiple pointers 31, 32 extending from the center 30 of the analog meter 2 toward the scale side.

[0050] 3, some analog meters 2 are provided with a plurality of pointers 31, 32. In the reading method of this embodiment, the number of pointers that the analog meter 2 is provided with is not limited.

[0051] In this step #4, based on the imaging data d1 obtained by imaging the analog meter 2, the calculation processor 22 reads the scale numbers (in the example of FIG. 3, "0", "1", "2", "3", "4", "5", "10", and "15") and detects the position of the center 30 of the analog meter 2 and the positions of the pointers 31, 32 by calculation processing such as an object detection algorithm. Note that reading the scale numbers here may include both reading the numbers themselves indicated by the scale numbers and reading the positions where the scale numbers are written.

[0052] The coordinates of the substantial center position where the scale numbers are written are preferably adopted as the positions where the scale numbers are written. The coordinates of the substantial center position here can be, for example, the coordinates of the center position of a plane figure such as a rectangle, a circle, an ellipse, etc. that circumscribes the area where the scale numbers are written. The center 30 of the analog meter 2 is a point that constitutes the fulcrum of the pointers 31, 32. In general, the analog meter 2 is configured so that the position of the center 30 can be visually distinguished from other points, and therefore can be identified by a calculation process based on the image data d1. For example, a screw hole is often provided at the center 30 of the analog meter 2.

[0053] This step #4 corresponds to process (c).

[0054] (Step #5: Measure angle) After executing step #4, the calculation processing unit 22 identifies the scale numbers located adjacent to the pointer to be read (here, the pointer 31). An example of a specific method will be described with reference to FIG.

[0055] The calculation processing unit 22 determines the equation in plane coordinates of a straight line L3 (corresponding to the "third straight line") that is a virtual extension of the pointer 31 to be read in a direction away from the center 30. Next, the calculation processing unit 22 identifies the two scale numbers closest to the line L3 from the positions in plane coordinates of each scale number read in step #4. In the example shown in FIG. 4, these are the scale marks "3" and "4". The pointer 31 is located between the scale marks "3" and "4". In this example, the scale mark "3" corresponds to the first scale mark, and the scale mark "4" corresponds to the second scale mark.

[0056] In this manner, the process in which the calculation processor 22 identifies the first scale number and the second scale number corresponds to step (d).

[0057] Next, the angle θ between a straight line L1 (corresponding to the "first straight line") connecting the first scale number A1 (in this example, the scale mark "3") and the center 30, and a straight line L2 (corresponding to the "second straight line") connecting the second scale number A2 (in this example, the scale mark "4") and the center 30 is identified.

[0058] For example, the calculation processing unit 22 can determine the equation of the first straight line L1 by calculating and identifying an equation on a plane coordinate system that connects the coordinate position of the center of the first scale number A1 (in this example, the scale mark "3") read in step #4 and the coordinate position of the center 30 of the analog meter 2.

[0059] As another example, generally, in analog meter 2, the scale markings at the portion where the scale markings are provided are often displayed (typically with a thick line, a long line, etc.) so as to be more noticeable than the other scale marks. Therefore, after identifying the scale marking corresponding to the first scale marking number A1 (in this example, scale marking "3") read in step #4, the equation on the plane coordinate system that connects this scale position with the coordinate position of the center 30 of analog meter 2 can be identified by arithmetic processing to obtain the equation of the first straight line L1.

[0060] Regarding the method for determining the equation of the second straight line L2, a method similar to the method for determining the equation of the first straight line L1 can be used by replacing the first scale number A1 (in the example of FIG. 4, "3") with the second scale number A2 (in the example of FIG. 4, "4").

[0061] When the equations of the first line L1 and the second line L2 are determined in this manner, the first angle θ between them can be calculated by arithmetic processing.

[0062] Next, the second angle φ between the first line L1 and the third line L3 connecting the needle 31 to be read and the center 30 of the analog meter 2 is calculated by calculation. Since the equations of the third line L3 and the first line L1 have already been calculated, the second angle φ can also be calculated by calculation in the same way as the angle θ.

[0063] After calculating the first angle θ and the second angle φ, the calculation processing unit 22 performs a calculation process of φ / θ to calculate the ratio k between the two.

[0064] In this manner, the process in which the calculation processor 22 calculates the ratio k between the first angle θ and the second angle φ corresponds to step (e).

[0065] (Step #6: Determine the indicated value) When the ratio k is calculated in step #5, the calculation processing unit 22 determines the reading of the pointer 31 by proportionally allocating the difference between the first scale number A1 and the second scale number A2 at the ratio k through calculation processing.

[0066] In the example of FIG. 4, the first scale number A1 is "3" and the second scale number A2 is "4", so the reading of the pointer 31 can be calculated by the calculation "3+(4-3)×k".

[0067] As shown in Figures 3 and 4, there are many analog meters 2 in which the intervals between the scale numbers are unevenly arranged. This is for the purpose of making it easier to read numbers in the range of likely values ​​by narrowing the range of unlikely values ​​when a range of possible values ​​is planned depending on how the analog meter 2 is used. Since the analog meter 2 is intended to be read visually in the first place, the aim is to make it easier to read visually by widening the range that is thought to be read frequently.

[0068] However, in such an analog meter 2, the intervals between the scale numbers are not uniform, making it difficult to read the pointer from only the position of each scale mark. Moreover, the intervals between the scale numbers vary depending on the type of analog meter 2 and the purpose of installation, making it difficult to preset information in advance in order to read all analog meters 2. Furthermore, as described above, depending on the location of the facility 1, it is assumed that an Internet connection is not possible, and it is also assumed that the process of reading the preset information from the server cannot be performed.

[0069] In contrast, according to the above method, the positions of the scale numbers, center 30, and pointer 31 of each analog meter 2 are detected by calculation based on the image data d1 of the analog meter 2, and the indicated value of the pointer 31 is specified by calculation based on a geometric method. Therefore, the scale numbers of the analog meter 2 can be read regardless of whether they are uneven or even. Also, there is no need to receive preset data from a server or the like via the Internet.

[0070] As mentioned above, analog meters 2 with uneven intervals between scale numbers are widely available, but analog meters 2 with uneven scale markings between adjacent scale numbers are almost nonexistent. This is because analog meters 2 are originally designed to be read by visual inspection. In other words, as described above, the difference between the first scale number A1 and the second scale number A2 is proportionally allocated at the ratio k by arithmetic processing, and the obtained value is used as the reading of the pointer 31, making it possible to obtain an indication value with little error.

[0071] As shown in FIG. 3, when an analog meter 2 has a plurality of pointers (31, 32) and the plurality of pointers (31, 32) are to be read, the same processes as those in steps #5 to #6 may be performed for each pointer.

[0072] Fig. 5 is a conceptual diagram similar to Fig. 4, in which pointer 32 is read instead of pointer 31. As shown in Fig. 5, the calculation processing unit 22 determines the equation, on the plane coordinate system, of straight line L3 (corresponding to the "third straight line") which is a virtual extension of the pointer 32 to be read in a direction away from the center 30. Next, the two scale numbers closest to line L3 are identified from the coordinate positions on the plane coordinate system of each scale number read in step #4. In the example shown in Fig. 5, these would be scale mark "3" and scale mark "4".

[0073] Next, a first angle θ formed by a straight line L1 (corresponding to the "first straight line") connecting the first scale number A1 (for example, the scale mark "3") and the center 30, and a straight line L2 (corresponding to the "second straight line") connecting the second scale number A2 (for example, the scale mark "4") and the center 30 is specified. Next, a second angle φ formed by the above-mentioned third straight line L3 connecting the pointer 32 to be read and the center 30 of the analog meter 2, and the first straight line L1 is calculated by arithmetic processing. Thereafter, the arithmetic processing unit 22 calculates the ratio k between the two by arithmetic processing of φ / θ, and determines the reading value of the pointer 32 by proportionally allocating the difference between the first scale number A1 and the second scale number A2 at the ratio k by arithmetic processing.

[0074] In the above example, the second angle φ is the angle between the third straight line L3 connecting the pointer 32 to be read and the center 30 of the analog meter 2, and the first straight line L1 connecting the first scale number A1 (for example, the scale "3" in this example) and the center 30. In contrast to this, the second angle φ may be the angle between the third straight line L3 connecting the pointer 32 to be read and the center 30 of the analog meter 2, and the second straight line L2 connecting the second scale number A2 (for example, the scale "4" in this example) and the center 30 (see FIG. 6).

[0075] In this case, after the calculation processor 22 calculates the ratio k of the first angle θ and the second angle φ, since the first scale number A1 is "3" and the second scale number A2 is "4", the reading of the pointer 32 can be calculated by the calculation process of "4-(4-3)×k". The pointer 31 may also be read in this manner.

[0076] This step #6 corresponds to process (f).

[0077] (Step #7: Output of indicated value) The needle reading value determined by the calculation processing unit 22 in the above step #6 is output from the output unit 24. This step #7 corresponds to the process (g).

[0078] At this time, as shown typically in Fig. 7, both the captured image 61 of the analog meter 2a captured in step #2 and the needle read value 62 determined in step #6 may be output to the output unit 24. Note that Fig. 7 illustrates an example in which "output to the output unit 24" is a screen display, but it may be a process in which a data string including the captured image 61 and the needle read value 62 is output to a storage medium.

[0079] 7 shows an example in which the imaging unit 11 and the arithmetic processing unit 20 are connected by wire 13, but as described above, the imaging unit 11 and the arithmetic processing unit 20 may be connected via short-distance wireless communication 14 (see FIG. 8). Furthermore, as described above, the external storage medium 15 built into the imaging unit 11 may be removed and attached to the arithmetic processing unit 20 (see FIG. 9).

[0080] (Step #8: Check the remaining analog meter reading) After step #7 is completed, it is confirmed whether there are other analog meters 2 to be read within the facility 1. If it is necessary to read the indicated value of another analog meter 2 (Yes in step #8), the process returns to step #1, and steps #1 to #7 are executed repeatedly. If there are no remaining analog meters 2 to be read (No in step #8), the reading process ends.

[0081] [Another embodiment] Another embodiment will be described below.

[0082] <1> When the imaging unit 11 is an operation terminal with an imaging function such as a tablet computer or a smartphone, the type of the analog meter 2a to be read may be selected by operating the device. Fig. 10 is a block diagram showing a schematic diagram of a system configuration when executing the reading method of this embodiment, together with a photograph showing an example of a state in which an operator 3 captures an image of the analog meter 2a using the imaging unit 11 mounted on the operation terminal made of a tablet computer. Figs. 11 and 12 are examples of screen displays of a tablet computer.

[0083] After or before moving to a position where an image of the analog meter 2a to be read can be captured, the worker 3 operates the tablet computer to select the type of the analog meter 2a to be read. Information on the type may be recorded in advance in the tablet computer. As described above, the analog meter reading method according to the present embodiment is also expected to be used when reading the analog meters 2, 2, ... installed in a facility 1 such as an electric power station during inspection and testing of various equipment installed in the facility 1. Therefore, it is often possible to know in advance, depending on the facility 1, what physical quantity the analog meters 2, 2, ... installed in the facility 1 are intended to measure.

[0084] For example, when an application for a tablet computer is executed, a plurality of inspection items registered in advance are displayed as shown in FIG. 11. The worker 3 selects an inspection item corresponding to the analog meter 2a to be read this time from among the plurality of inspection items displayed. This starts the imaging unit 11, and information on the type of analog meter corresponding to the selected inspection item is displayed on the tablet screen (see FIG. 12). FIG. 12 is an example of a display on the tablet screen, and includes an imaging display area 51, a type information display area 52 for the analog meter 2a, and an operation area 53 for the imaging unit 11. In the example of FIG. 12, the analog meter 2a is identified as an oil temperature gauge for a transformer mounted in a substation, and information on the oil temperature gauge is also displayed.

[0085] The worker 3 visually checks the shooting display area 51 and adjusts the shooting direction, while operating the operation buttons in the operation area 53 to perform the shooting process.

[0086] The imaging data d1 obtained by imaging is input to an external arithmetic processing device 20 connected to the tablet computer, and arithmetic processing is performed by the method described above. The read values ​​obtained by the arithmetic processing are transmitted to the tablet computer and displayed on the tablet screen (see FIG. 13). In FIG. 13, similar to the above description with reference to FIG. 7, an image 61 of the analog meter 2a and a read value 62 of the pointer are displayed on the tablet screen. Note that in the example of FIG. 13, the results of reading the indicated values ​​of three pointers (a pointer corresponding to the current value, a pointer corresponding to the maximum value, and a pointer corresponding to the upper limit value) are displayed.

[0087] By recording data including the captured image 61 and the read value 62, it is expected that the evidential capability of the indicated value of the analog meter 2a read in conjunction with an inspection operation or the like can be improved.

[0088] 12 and 13, when an analog meter 2 has multiple pointers, the pointers often have different lengths, colors, thicknesses, etc., in order to distinguish between the pointers. When a target inspection item is selected and the type of analog meter 2 is specified, information regarding the contents of the quantities indicated by each pointer may be stored in the tablet computer.

[0089] As an example, an analog meter 2 constituting an oil temperature gauge mounted on a transformer has three pointers, the colors of which are white, red, and yellow, and the white pointer corresponds to the current value, the red pointer corresponds to the maximum value, and the yellow pointer corresponds to the upper limit, which are recorded in the tablet computer. After reading the indicated value of each pointer using the above method, the current value, the maximum value, and the upper limit value can be output by matching them to the recorded information.

[0090] As another example, if the analog meter 2 has three pointers corresponding to the "current value", "maximum value", and "upper limit value", the relationship between the values ​​indicated by these three pointers is always current value≦maximum value<upper limit value. In this way, when the magnitude relationship between the values ​​indicated by each pointer is specified, information on the relationship may be recorded in the tablet computer. In this case, it is not necessarily necessary to distinguish and read the indicated value of the pointer, which is specified by the color, length, or thickness of the pointer. Specifically, after reading the indicated value (group of indicated values) indicated by each of the three pointers using the above-mentioned method, it may be specified whether the value indicated by each pointer is the "current value", the "maximum value", or the "upper limit value" based on the relational equation recorded in the tablet computer.

[0091] Note that the above information is not necessary for reading the analog meter, but is merely information used when outputting data. In other words, in the above example, if the values ​​indicated by the white, red, and yellow pointers are output, it is not necessary to output what quantity each pointer value corresponds to.

[0092] 14, an arithmetic processing device 20 configured with a tablet computer or the like may be equipped with the imaging unit 11, and the above-mentioned arithmetic processing may be performed within this arithmetic processing device 20. In other words, the arithmetic processing unit 22 and the imaging unit 11 may be equipped in the same device (arithmetic processing device 20). In this case, the imaging data d1 does not need to be input to another device for arithmetic processing.

[0093] <3> In the case where the arithmetic processing device 20 and the imaging unit 11 are configured as separate devices, in the above embodiment, the arithmetic processing device 20 is installed in the facility 1, but it may be installed near the premises of the facility 1. In other words, the arithmetic processing device 20 may be installed within the reach of a wireless LAN in the facility 1.

[0094] <4> Depending on the facility 1, it may be assumed that a fixed camera capable of photographing the analog meter 2 has already been installed. In such a case, the fixed camera may be employed as the imaging unit 11, and the imaging data d1 obtained by photographing the analog meter 2 with the fixed camera may be input to the arithmetic processing device 20, and the arithmetic processing unit 22 may perform the arithmetic processing in the above-mentioned manner. In this case, the above-mentioned step #1 may be omitted. [Explanation of symbols]

[0095] 1: Facilities 2,2a: Analog meter 3: Worker 11: Imaging section 13:Wired 14: Wireless communication 15:External storage medium 20: Processing unit 21: Input reception section 22: Processing unit 23: Storage section 24: Output section 30: Center of analog meter 31,32 :Guidelines 51: Shooting display area 52: Type information display area 53: Operation area 61: Captured image 62 : Reading value A1 :First scale number A2 :Second scale number L1: First straight line L2: Second straight line L3: Third straight line d1: Image data

Claims

1. 1. A method for reading a plurality of analog meters installed in a facility, comprising: A step (a) of capturing an image of the analog meter to be read by an imaging unit to obtain imaging data; a step (b) of inputting the imaging data via a storage medium or via a communication line configured as a wired or wireless non-internet to a calculation processing unit that is mounted in the same device as the imaging unit or in a device separate from the imaging unit and installed within or near the site of the facility and that is unable to read information related to the analog meter because the information is not registered in advance; (c) detecting, from the imaging data, the scale numbers displayed on the analog meter, the position of the pointer, and the center position of the analog meter by calculation processing without reading out any information previously registered with respect to the analog meter by the calculation processing unit; a step (d) in which the calculation processing unit identifies a first scale number and a second scale number that is greater in value than the first scale number and that are located adjacent to the pointer detected in the step (c); a step (e) in which the arithmetic processing unit calculates a first angle θ formed by a first line connecting the substantial center position of the first scale numeral or the scale position corresponding to the first scale numeral and the center position of the analog meter, and a second line connecting the substantial center position of the second scale numeral or the scale position corresponding to the second scale numeral and the center position of the analog meter, and a ratio k of a second angle φ formed by a third line connecting the pointer and the center position of the analog meter and the first line or the second line; and (f) a step in which the calculation processing unit determines a reading of the pointer based on a value obtained by proportionally allocating the difference between the first scale number and the second scale number at the ratio k, A method for reading an analog meter, comprising performing steps (a) to (f) for each of the plurality of analog meters.

2. 2. The analog meter reading method according to claim 1, wherein the step (a) is a step in which an operator moves the analog meter to be read to a position where an image of the analog meter can be captured, and captures an image of the analog meter using a device equipped with the imaging unit.

3. and (g) outputting, to an output unit, the image data of the analog meter obtained in the step (a) and information relating to the needle reading obtained in the step (f), 3. The method for reading an analog meter according to claim 1, wherein step (g) is performed for each of the plurality of analog meters.

4. 3. The method for reading an analog meter according to claim 1, wherein the analog meter to be read in step (a) has scale numbers written thereon spaced at uneven intervals.

5. 3. The method for reading an analog meter according to claim 1, wherein the facility is an electric power station.

6. The step (e) is a step of calculating, by the calculation processing unit, a ratio k of a second angle φ between the third straight line and the first straight line to the first angle θ, 3. The method for reading an analog meter as claimed in claim 1 or 2, characterized in that step (f) is a step in which the calculation processing unit adds the value of the first scale number to a value obtained by proportionally allocating the difference between the first scale number and the second scale number at the ratio k, thereby determining the value as the reading of the pointer.

7. The step (e) is a step of calculating, by the calculation processing unit, a ratio k of a second angle φ between the third straight line and the second straight line to the first angle θ, 3. The method for reading an analog meter as claimed in claim 1 or 2, characterized in that step (f) is a step in which the calculation processing unit subtracts a value obtained by proportionally allocating a difference between the first scale number and the second scale number at the ratio k from the value of the second scale number to determine the pointer reading value.

8. 3. The method for reading an analog meter according to claim 1, wherein the arithmetic processing unit is mounted in an arithmetic processing device that cannot be connected to the Internet.

Images