Calculation system, computer program, and calculation method

Abstract

To calculate the height from a reference portion of a target portion in a target object.SOLUTION: A calculation method includes: acquiring measurement data measured by a measurement instrument and related to a target object that passes through an irradiation range of laser light (S110) when the target object is displaced relative to the measurement instrument along with displacement of one of the measurement instrument and the target object; calculating the height, from a reference portion, of at least one target portion in the target object, on the basis of the measurement data; measuring, by the measurement instrument, a relative position in the target object to a reflection point; determining a measurement value of the relative position in the vicinity of the reference portion where a false measurement occurs, as an invalid measurement value (S130); calculating a reference position corresponding to the reference portion by extrapolation based on the measurement data excluding the invalid measurement value; and calculating the height from the reference portion of the target portion on the basis of a comparison with the reference position (S140).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a calculation system and a calculation method. [Background technology]

[0002] The light-section method is known as a method for measuring the shape of an object. In the light-section method, a laser beam is irradiated toward the object and the light reflected from the object is received. The bright spot where the laser beam is reflected is observed at a location away from the object.

[0003] The position of the bright spot at the observation point changes depending on the relative position between the observation point and the bright spot. By applying the difference in the positions of the bright spots to the principle of triangulation, the relative position from the observation point to the bright spot can be quantified. According to the light section method, the outline of the object can be imaged to show a cross section of the object based on the quantified relative position.

[0004] Conventionally, the thickness of the contact strip of a pantograph is calculated using this light section method (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-41943 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, when using a method for measuring the relative position to an object, in order to calculate the thickness of the object, information on the relative position to a reference portion corresponding to the origin position of the thickness is required in addition to the relative position to the object portion, which is the portion for which the thickness is to be calculated.

[0007] However, when the measurement of the relative position by irradiating laser light is performed while either the object or the measuring instrument is moving, the movement may change the incidence of the laser light on the object, resulting in an erroneous measurement of the relative position.

[0008] In particular, at the leading edge of the object where the laser light starts to partially enter the object, erroneous measurement of the relative position may occur. Therefore, in an environment where it is necessary to set the reference portion at the leading edge of the object, it is difficult to calculate the thickness of the object, i.e., the height from the reference portion of the object to the target portion, with high accuracy unless the influence of erroneous measurement is properly eliminated. This also occurs when the reference portion is set at the rear end of the object where the laser light partially enters.

[0009] Therefore, according to one aspect of the present disclosure, it is desirable to provide a technique that can calculate the height of a target part of an object from a reference part with high accuracy. [Means for solving the problem]

[0010] According to one aspect of the present disclosure, a calculation system is provided for calculating the height of an object passing through an irradiation range of a laser beam by a measuring instrument based on relative movement of the object with respect to the measuring instrument that accompanies movement of either the measuring instrument or the object.

[0011] The calculation system includes an acquisition unit and a calculation unit. The acquisition unit is configured to acquire measurement data from a measuring device. The calculation unit is configured to calculate a height of at least one target portion of the object from a reference portion of the object based on the measurement data.

[0012] The measuring device is configured to measure a relative position to a reflection point on the object by applying a laser beam to an irradiation area and receiving the reflected beam from the object passing through the irradiation area using the principle of triangulation. The measuring device is configured to output measurement data describing the relative position.

[0013] The reference portion may correspond to a leading portion of the object where the object enters the irradiation range due to relative movement, the laser light is incident on the object, and the measurement of the relative position by the measuring device starts due to the reflection of the laser light on the object. Alternatively, the reference portion may correspond to a trailing end portion of the object located on the opposite side to the leading portion in the direction of relative movement of the object.

[0014] The calculation unit is configured to determine, as an invalid measurement value, a measurement value of the relative position around a reference portion where an erroneous measurement of the relative position occurs due to the laser light being partially incident on the object in the beam diameter direction.

[0015] The calculation unit is configured to calculate a relative position in the reference portion as a reference position by extrapolation based on the measurement data excluding invalid measurement values. The calculation unit is configured to calculate a height of the at least one target portion from the reference portion based on a comparison between the relative position of the at least one target portion indicated by the measurement data and the reference position.

[0016] According to this calculation system, it is possible to calculate the height of a target part of an object from a reference part with high accuracy while suppressing the influence of erroneous measurement.

[0017] According to one aspect of the present disclosure, the calculation unit may be configured to determine a function corresponding to a surface shape of the object by function fitting to a group of measurement values ​​at multiple points of the object adjacent to a reference portion, excluding invalid measurement values ​​indicated by the measurement data. The calculation unit may be configured to calculate a reference position based on the determined function. By calculating the reference position by extrapolation based on the function determined by function fitting, it is possible to calculate the reference position with high accuracy.

[0018] According to an aspect of the present disclosure, the calculation unit may be configured to determine an invalid measurement value based on a measurement period of the relative position by irradiation of the laser light, a relative speed of the object with respect to the measuring device, and a beam diameter. With this configuration, it is possible to appropriately determine an invalid measurement value.

[0019] According to an aspect of the present disclosure, the calculation system may include a measuring device. The relative movement of the object with respect to the measuring device may be relative movement along a predetermined travel surface. In this case, the measuring device may include a line laser as an element for emitting the laser light. The line laser may be arranged to irradiate the laser light in a line shape in an oblique direction along the travel surface having an angle of less than 90 degrees with respect to the relative movement direction of the object with respect to the measuring device, thereby irradiating the laser light in a line shape in an oblique direction with respect to the object.

[0020] With this arrangement, the line laser can be positioned so that laser light can be irradiated to multiple points lined up in a direction along the traveling surface and perpendicular to the direction of relative movement, and the relative positions of multiple points in the direction perpendicular to the relative movement direction of the object can be measured using a single line laser.

[0021] The above-mentioned arrangement of the line laser further prevents the reference portion and / or the target portion of the object from passing through the irradiation position of the laser light during the period when the laser light is not irradiated, when the laser light is irradiated periodically. This prevention effect works more effectively when the reference portion and / or the target portion are portions that extend longer in the direction perpendicular to the relative movement direction. As a result, the height of the target portion relative to the reference portion can be appropriately calculated.

[0022] According to one aspect of the present disclosure, the object may have an elongated outer shape extending in a direction along the travel surface and in a direction intersecting the relative movement direction. The reference portion may correspond to a linear portion extending in the elongated direction. The at least one target portion may include a plurality of target portions located apart in the elongated direction on the object. The oblique direction may be set such that the laser light can irradiate the reference portion and the plurality of target portions during a period in which the object moves relatively within the irradiation range.

[0023] According to one aspect of the present disclosure, the object may be an object mounted on a vehicle. In this case, the measuring device may be installed on a path of travel of the vehicle. According to one aspect of the present disclosure, the object may be something that is installed on a path of travel of the vehicle. In this case, the measuring device may be mounted on the vehicle. According to one aspect of the present disclosure, the vehicle may be a railroad car.

[0024] According to an aspect of the present disclosure, a computer program for causing a computer to function as at least one of the acquisition unit and the calculation unit included in the calculation system described above may be provided. The computer program may be recorded in a computer-readable, non-transitive, tangible recording medium.

[0025] According to an aspect of the present disclosure, a calculation method corresponding to the above-described calculation system may be provided. According to an aspect of the present disclosure, a calculation method may be provided for calculating, by using a measuring device, a height of an object passing through an irradiation range of a laser beam by the measuring device, based on a relative movement of the object with respect to the measuring device that accompanies a movement of one of the measuring device and the object. The calculation method may be executed by a computer.

[0026] The calculation method may include obtaining measurement data from a measuring device, and calculating a height of at least one target portion of the object from a reference portion of the object based on the measurement data.

[0027] The measuring device may be configured to measure a relative position to a reflection point on the object by applying a laser beam to an illumination range and receiving reflected light from the object passing through the illumination range using the principle of triangulation. The measuring device may be configured to output measurement data describing the relative position as measurement data.

[0028] The reference portion may correspond to a leading portion of the object where the object enters the irradiation range due to relative movement, the laser light is incident on the object, and the measurement of the relative position by the measuring device starts due to the reflection of the laser light on the object. Alternatively, the reference portion may correspond to a trailing end portion of the object located on the opposite side to the leading portion in the direction of relative movement of the object.

[0029] Calculating the height may include classifying measurements of the relative position around a reference portion, where an erroneous measurement of the relative position occurs due to the laser light being partially incident on the object in the beam diameter direction, as invalid measurements.

[0030] Calculating the height may include calculating a relative position at a reference site as a reference position by extrapolation based on measurement data excluding invalid measurements.

[0031] Calculating the height may include calculating the height of the at least one target portion from the reference portion based on a comparison between the relative position of the at least one target portion indicated by the measurement data and the reference position. This calculation method has the same effects as the calculation method described above. [Brief description of the drawings]

[0032] [Figure 1] FIG. 1 is a block diagram showing a configuration of a measurement system. [Diagram 2] 2A and 2B are diagrams illustrating an example of the relationship between a measuring device and an object. [Diagram 3] 11 is a flowchart showing an analysis process executed by a processor of the analysis device. [Figure 4] FIG. 4A is a diagram for explaining an example of laser scanning on an object, and FIG. 4B is a diagram for explaining another example of laser scanning as a reference example. [Diagram 5] FIG. 5 is a side view of the object. [Figure 6] 6A and 6B are diagrams illustrating the incidence of laser light as viewed from above an object. [Figure 7]7A and 7B are diagrams illustrating the incidence of laser light as viewed from the side of an object. [Figure 8] 8A and 8B are explanatory diagrams relating to the deletion of erroneous measurement values. [Figure 9] 11 is a flowchart showing a thickness calculation process executed by a processor of the analysis device. [Figure 10] 10A and 10B are diagrams for explaining determination of the reference position by function fitting and extrapolation. [Figure 11] 13 is a flowchart showing a thickness calculation process according to a modified example. [Figure 12] FIG. 12A is a plan view of the contact strip, and FIG. 12B is a cross-sectional view of the contact strip taken along the line AA'. [Figure 13] FIG. [Figure 14] 14A, 14B, and 14C are diagrams for explaining differences in measurement intervals in the long dimension direction depending on the laser scanning angle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Exemplary embodiments of the present disclosure will now be described with reference to the drawings. [First embodiment] 1 is configured to use a measuring device 10 to measure the height from a reference site P1 (see FIG. 5) of an object C to a target site P2 as a thickness H of the target site P2 of the object C. Below, an example will be described in which there are multiple measurement points for the thickness H on the object C, i.e., an example in which there are multiple target sites P2, but there may be only one target site P2.

[0034] The measuring instrument 10 is configured to irradiate laser light onto the object C and receive the reflected light, thereby measuring the relative position from an observation point corresponding to the installation point of the measuring instrument 10 to a reflection point on the object C using the principle of triangulation, specifically the principle of the light section method.

[0035] According to a first example, the measurement system 1 operates in an environment in which an object C is installed along a track 4 and a measuring device 10 is mounted on a railway vehicle 5 traveling on the track 4, as shown in Fig. 2A. The track 4 corresponds to the travel path of the railway vehicle 5. According to this example, a laser beam is irradiated from above from the measuring device 10, which moves together with the railway vehicle 5, towards a stationary object C located in front of the railway vehicle 5.

[0036] 2B , the measurement system 1 operates in an environment in which the object C is a mounted component of a railway vehicle 5 and the measuring device 10 is fixed to a support 7 installed near the track 4. According to this example, a laser beam is irradiated from above from the stationary measuring device 10 towards the object C passing below the measuring device 10 together with the railway vehicle 5.

[0037] The example shown in Figures 2A and 2B is an example in which the thickness H of the target portion P2 of the object C is measured based on the results of the measuring instrument 10 irradiating the object C with laser light as it passes through the irradiation range of the laser light in an environment in which the object C moves relative to the measuring instrument 10 as one of the measuring instrument 10 or the object C moves along a running surface (specifically, the track 4).

[0038] According to this embodiment, the measuring device 10 measures the height direction relative position of the object C with respect to the traveling surface by laser scanning along the traveling surface. Based on a comparison between the relative position of the reference portion P1 and the relative position of the object portion P2, the thickness H of the object C is measured.

[0039] 1, the measurement system 1 includes a measurement device 10 and an analysis device 50. The measurement device 10 includes a line laser 11 and a light receiving sensor 15. The line laser 11 is configured to irradiate a line of laser light onto a predetermined irradiation range along a traveling surface.

[0040] When an object C that generates reflected light is present within the irradiation range, the light receiving sensor 15 receives the reflected light from the object C. The measuring instrument 10 measures the relative position to the reflection point of the object C that generated the reflected light, based on the position of the bright point corresponding to the reflection point identified from the light receiving image by the light receiving sensor 15, using the principle of triangulation.

[0041] Measuring instrument 10 outputs measurement data describing the measurement value of this relative position. Measuring instrument 10 can provide the measurement data to analyzing device 50 through communication with analyzing device 50. The relative position described as a measurement value in the measurement data is the relative position in the height direction of the reflection point with respect to the observation point of measuring instrument 10, as described above.

[0042] The line laser 11 is configured to periodically perform laser scanning. The scanning period is, for example, 1 / 15000 seconds. In this case, the line laser 11 performs laser scanning at a sampling frequency f=15000 Hz.

[0043] Measuring instrument 10 operates to measure the relative position of each point of object C in the direction of relative movement at this sampling frequency f. Hereinafter, the reciprocal of the scanning period will be expressed as sampling frequency f. The scanning period corresponds to the measurement period of the relative position in the direction of relative movement.

[0044] Measurement of the relative position by the measuring instrument 10 can be started when the object C enters the irradiation range due to relative movement with respect to the measuring instrument 10 and the light receiving sensor 15 starts receiving the light reflected from the object C, and can be ended when the object C leaves the irradiation range and the reception of the reflected light ends. Alternatively, the measuring system 1 can be configured to perform measurement for a fixed time after the object C or the railcar 5 is detected.

[0045] The measurement data includes a group of measurement values ​​obtained by multiple laser scans performed during this measurement period. During laser scanning, a laser beam having a predetermined beam diameter and a circular beam cross section is emitted from the line laser 11. The relative distance to the reflection point resulting from the emission is recorded as a measurement value based on the light reception result by the light receiving sensor 15.

[0046] The measurement data includes an array of measurement values ​​for each laser scan. The array of measurement values ​​includes, as measurements, information on the relative position to the reflection point measured for each reception of reflected light based on the laser light emitted in the corresponding scan.

[0047] Analysis device 50 is configured to calculate the height from reference portion P1 to target portion P2 of object C as thickness H of target portion P2 of object C, using the measurement data provided by measuring device 10.

[0048] As shown in FIG. 1, the analysis device 50 includes a processor 51, a memory 53, a storage 55, a user interface 57, and a communication interface 59. 5 stores a computer program for calculating the thickness H using the measurement data.

[0049] The processor 51 executes processing according to the computer program to calculate the thickness H. The memory 53 includes a RAM that is used as a working area when the processor 51 executes processing according to the computer program.

[0050] The user interface 57 is configured to input an operation signal from a user to the processor 51. The user interface 57 is further configured to display various information for the user under the control of the processor 51. The user interface 57 can include, for example, a keyboard and a pointing device as an operation unit, and a liquid crystal display as a display unit.

[0051] Communications interface 59 is configured to be able to communicate with an external device. Communications interface 59 may be configured to be able to communicate with measuring instrument 10 as an external device. Communications interface 59 may include a serial communications interface such as a Universal Serial Bus (USB) interface.

[0052] The measurement system 1 may further include a detection sensor 20 that detects the object C entering the irradiation range. The detection sensor 20 may be configured to input a detection signal regarding the object C entering the irradiation range to the measurement device 10 and the analysis device 50.

[0053] When the detection signal is input, processor 51 of analysis device 50 executes the analysis process shown in Fig. 3 in accordance with a computer program stored in storage 55. In the analysis process, processor 51 acquires from measuring instrument 10 the above-mentioned measurement data describing a group of measurement values ​​obtained by multiple laser scans performed when object C passes through the irradiation range (S110).

[0054] In the next step S120, the processor 51 performs projective transformation on the measurement data. As shown in Fig. 4A, the line laser 11 of this embodiment irradiates the laser light on a straight line inclined at an angle of less than 90 degrees with respect to the relative movement direction of the object C. As a result, the line laser 11 irradiates the laser light on the object C in a line shape inclined obliquely with respect to the relative movement direction.

[0055] The thick dashed line shown in Fig. 4A conceptually represents laser scanning. The white circles shown in Fig. 4A indicate points where the relative positions are measured by irradiation with laser light, that is, parts of the measurement points.

[0056] As described above, the measurement data includes an array of measurement values. In the measurement data, the measurement points of each measurement value are aligned along the x direction of the scan. s y perpendicular to the axis and the scanning direction s It is expressed in a two-dimensional coordinate system defined by the axes.

[0057] x scorresponds to the array number representing the position from the beginning of each measurement point aligned in the scanning direction, and y s x corresponds to the array number representing the position from the beginning of each measurement point aligned in the direction perpendicular to the scanning direction. s Axis and y s x defined by axis s y s The plane is along the running surface. Each measurement is x s y s It corresponds to the value in the height direction perpendicular to the plane, i.e., the z-axis direction.

[0058] Meanwhile, the analysis device 50 calculates the thickness H at each measurement point along the relative movement direction in order to explain the thickness H of the object C to the user in an easy-to-understand manner. That is, with regard to the thickness H, the position of each measurement point is expressed in a two-dimensional coordinate system defined by the y-axis along the relative movement direction and the x-axis perpendicular to the relative movement direction.

[0059] The projective transformation in S120 converts the position coordinates of each measurement point in the measurement data into x s y s After the projective transformation in S120, the processor 51 performs a process for deleting erroneous measurement values ​​included in each data sequence of measurement values ​​corresponding to a sequence of measurement points aligned in the y-axis direction parallel to the relative movement direction, using the measurement data after the projective transformation (S130).

[0060] 4A, the object C may be a railway part 100 having a body 110 and a bolt 120 fastened thereto. The measurement of the thickness H of the object C may be performed, for example, to detect loosening of the bolt 120.

[0061] Fig. 5 shows a side structure of the object C (railroad part 100) when the object C is viewed in a direction parallel to the traveling surface, specifically, in a horizontal direction. As shown in Fig. 5, when the object C moves relatively from right to left in Fig. 5 within the irradiation range of the laser light, and the laser light starts to be incident on the object C, the laser light changes from a state in which a part of the beam diameter direction is partially incident on the object C as shown in Figs. 6A and 7A to a state in which the entire beam diameter direction is incident on the object C as shown in Figs. 6B and 7B.

[0062] 6A, 6B, 7A, and 7B, solid arrows indicate the incidence of laser light, and dashed arrows indicate the reflection of laser light. The dashed lines surrounding the arrows conceptually indicate the outline of a beam having a width, specifically, the beam cross section and beam width.

[0063] The measuring instrument 10 calculates the relative position on the premise that the entire beam diameter direction of the laser light is incident on the object C and is reflected from the object C. In other words, the measuring instrument 10 treats the laser light having a width called the beam diameter as a virtual laser light with no width, considers the laser light to be present at the center of the beam diameter where the intensity is maximum, and calculates the relative position by the principle of triangulation.

[0064] Therefore, the relative position measured when the laser light is partially incident on the object C in the beam diameter direction and the entire beam diameter direction of the laser light is not irradiated on the object C includes a large error as shown in Fig. 7A. The white circles shown in Fig. 7A and Fig. 7B indicate that the relative position is measured by the principle of triangulation assuming that there is a reflection point there. The relative position is measured with high accuracy when the laser light is irradiated on the object C entirely in the beam diameter direction as shown in Fig. 7B.

[0065] That is, the measurement data includes information on erroneously measured measurement values ​​at a measurement point corresponding to the periphery of the leading portion of the target C where the laser light starts to enter. The deletion of erroneous measurement values ​​in S130 is a process of deleting measurement values ​​of relative positions erroneously measured due to beam chipping as erroneous measurement values, in other words, invalid measurement values, from the measurement data.

[0066] In Fig. 8A, reflection points corresponding to erroneous measurement values ​​are represented by white circles with an X symbol inside, and reflection points corresponding to normal measurement values ​​are represented by white circles with a + symbol inside. In S130, the processor 51 deletes the erroneous measurement values ​​from the measurement data including the erroneous measurement values ​​as shown in the left of Fig. 8A, and generates measurement data including no erroneous measurement values ​​as shown in the right of Fig. 8A.

[0067] Specifically, for each data string of measurement values ​​corresponding to a row of measurement points arranged backward from the beginning of the relative movement direction of the object C (i.e., in the y-axis direction), as shown in FIG. 8B, the processor 51 determines a predetermined number N of measurement values ​​from the beginning of the data string as erroneous measurement values ​​and deletes them from the data string.

[0068] The predetermined number N is expressed by the following equation using the above-mentioned sampling frequency f [Hz] in the measuring device 10, the relative velocity v [m / s] of the object C, and the thickness of the laser light (i.e., the beam diameter) T [m].

[0069] N=T f / v As described above, the sampling frequency f corresponds to the reciprocal of the scanning period. Therefore, f / v corresponds to the number of measurement points per unit length in the relative movement direction of the target C. In other words, the predetermined number N corresponds to the number of measurement points in a section whose length corresponds to the thickness of the laser light in the y-axis direction.

[0070] The beginning of the data string corresponds to the first measurement value measured when the laser light is incident on the beginning of the target C. Therefore, by removing the number N of measurement values ​​calculated by the above formula from the beginning of the data string, it is possible to delete measurement values ​​that are estimated to be erroneous measurement values ​​from the data string.

[0071] In the next S140, the processor 51 determines the relative position of the reference part P1 as the reference position Bz, and calculates the height of each measurement point from the reference position Bz as the thickness H of each measurement point. In this embodiment, the reference part P1 is set to the leading part of the object C. As described above, the leading part corresponds to the point where the object C enters the irradiation range due to relative movement, the laser light is incident on the object C, and measurement of the relative position by the measuring device 10 starts due to reflection of the laser light on the object C.

[0072] In S140, the processor 51 executes the thickness calculation process shown in Fig. 9. When the processor 51 starts the thickness calculation process, it selects one of a plurality of data strings as a processing target string for data strings of measurement values ​​arranged from the beginning to the end in the relative movement direction (y-axis direction) (S210).

[0073] In the next step S220, the processor 51 performs function fitting on the processing target sequence. The processing target sequence corresponds to a sequence of measurement values ​​at each measurement point aligned along the relative movement direction in an area adjacent to the reference site P1, i.e., a sequence of relative positions on the surface of the object C.

[0074] According to this embodiment, the surface of the object C around the leading portion is an inclined straight line in a cross section parallel to the height direction. Therefore, the processor 51 fits the processing target sequence shown in Figures 10A and 10B with a linear function. In this way, an approximation line L for the processing target sequence is obtained. It can be said that the approximation line L approximately represents the surface shape around the leading portion of the object C.

[0075] Fig. 10A shows the measured relative positions as white circles with + signs along with the outline of the object C. Fig. 10A illustrates how an approximation line L is obtained by function fitting using a linear function to the sequence of relative positions shown by the white circles.

[0076] FIG. 10B is a diagram in which the relative positions of each measurement point corresponding to the processing target column are plotted on a graph having a horizontal axis corresponding to the y axis and a vertical axis corresponding to the z axis. The z axis corresponds to the height direction perpendicular to the xy plane, and is a dimension corresponding to the measurement value of the relative position. FIG. 10B illustrates an example of calculating the reference position Bz by linear approximation of the plotted points. n in FIG. 10B indicates the array number of the measurement value from the beginning of the processing target column from which the erroneous measurement value has been removed.

[0077] In the next S230, processor 51 determines the relative position of reference part P1 by extrapolation based on approximation line L. Specifically, processor 51 determines, as the relative position of reference part P1, a point that is a distance T / 2, corresponding to beam radius T / 2, upstream in the relative movement direction along approximation line L from the relative position of the measurement point corresponding to the beginning of the processing target row.

[0078] The relative position of the measurement point corresponding to the beginning of the processing target column is represented as z(1), and the slope of the approximation line L is is expressed as dz / dy, the relative position of the reference site P1, i.e., the reference position Bz, can be expressed by the equation Bz = z(1) - (dz / dy) · (T / 2).

[0079] In the next step S240, the thickness H of the object C at each measurement point corresponding to the processing target row is calculated as the difference between the measurement value Mz of the relative position at each measurement point and the reference position Bz. That is, the thickness H is calculated by the following equation: H=|Mz-Bz|.

[0080] In the next S245, the processor 51 determines whether or not all of the multiple data strings have been selected as the processing target strings and the processing from S220 onwards has been performed. If all of the multiple data strings have not been selected as the processing target strings (No in S245), the processor 51 selects a new processing target string from the multiple data strings (S210), performs the processing from S220 onwards, and calculates the thickness H of the object C at each measurement point corresponding to the processing target string (S240).

[0081] When the processor 51 determines that all of the multiple data columns have been selected as columns to be processed (Yes in S245), it ends the thickness calculation process shown in Fig. 9 and executes the process of S150 (see Fig. 3). In S150, the processor 51 outputs the calculation data describing the calculated thickness H = H (x, y) for each measurement point (x, y), for example, to be written to the storage 55 or to be displayed to the user via the user interface 57. Thereafter, the processor 51 ends the analysis process shown in Fig. 3.

[0082] The measurement system 1 of the present embodiment described above has the following advantages: As described above, in the case where the object C moves relative to the measuring device 10, the laser light is partially missing in the beam diameter direction at the leading portion of the object C and enters the object C, causing an erroneous measurement of the relative position.

[0083] In this embodiment, measurements obtained due to erroneous measurements are deleted from the measurement data, and then the relative position of the leading portion of the object C is determined by function fitting using the previously known outer shape around the leading portion of the object C. Therefore, when calculating the thickness H of the object C based on the leading portion of the object C, it is possible to calculate the thickness H with high accuracy while suppressing the influence of erroneous measurements.

[0084] In this embodiment, further, as shown in Fig. 4A, laser scanning is performed in an oblique direction having an angle of less than 90 degrees with respect to the relative movement direction. If laser scanning is performed at an angle of 90 degrees with respect to the relative movement direction as in the reference example shown in Fig. 4B, it is considered that the leading part of the object C cannot be measured when the object C moves relatively at a high speed compared to the sampling frequency f. That is, it is considered that the leading part of the object C passes through the irradiation range of the laser light between the end of the first scan and the start of the second scan.

[0085] By performing laser scanning in a direction oblique to the relative movement direction as in this embodiment, it is possible to suppress the occurrence of the above-mentioned measurement failure-related phenomena that occur when laser scanning is performed at an angle of 90 degrees to the relative movement direction. Therefore, the technology of this embodiment is particularly useful when the object C moves relatively to the measuring device 10 at high speed.

[0086] For example, when considering applying the technology of this embodiment to railways, the above-mentioned measurement failure is more likely to occur when the railway vehicle 5 runs at high speed on the main line than when it runs at low speed inside an inspection and maintenance depot.

[0087] Therefore, the technology of this embodiment is particularly useful when measuring the thickness H of the target object C in an environment where the railway vehicle 5 is moving at high speed on the main line. When the railway vehicle 5 is traveling on the main line at a speed of 70 km / h, the distance resolution in the relative movement direction at a sampling frequency f=15000 Hz is , approximately 1 mm (millimeter) to 2 mm, specifically 1.30 mm.

[0088] [Modification of thickness calculation process] Here, a modified example of the thickness calculation process described with reference to Fig. 9 will be described with reference to Fig. 11. The processor 51 can calculate the thickness H at each measurement point by executing the thickness calculation process shown in Fig. 11 instead of the thickness calculation process shown in Fig. 9. In the thickness calculation process of the modified example shown in Fig. 11, it may be understood that the same process as the thickness calculation process shown in Fig. 9 is executed in the steps having the same step numbers as those in Fig. 9.

[0089] When the thickness calculation process shown in FIG. 11 is performed, the processor 51 selects one of a plurality of data strings as a processing target string with respect to the data string of the measurement values, as described above (S210).

[0090] In the next step S220, the processor 51 executes function fitting for the sequence to be processed, and in step S230, determines the relative position of the reference site P1 by extrapolation based on the approximation line L.

[0091] Processor 51 executes the processes of S210 to S230 for each of a plurality of data strings while switching the string to be processed. When it is determined that the processes up to S230 have been executed for all data strings (Yes in S230), processor 51 executes the process of S250.

[0092] In S250, the processor 51 calculates a representative value Bz0 of the reference position Bz common to a plurality of data strings by performing statistical processing on the reference position Bz determined in S230 for each data string. For example, the processor 51 can calculate the average value of the reference positions Bz as the representative value Bz0 of the reference position Bz.

[0093] The representative value Bz0 is calculated here because the reference portion P1 is a linear portion parallel to the traveling surface, and the reference position Bz is ideally a value that has the property of showing the same value across multiple data strings.

[0094] Thereafter, the processor 51 uses the representative value Bz0 calculated in S250 to calculate the thickness H of each measurement point from the reference site P1 according to the following equation: H=|Mz-Bz0| (S260). This modified example also makes it possible to accurately calculate the thickness H of the target site P2 of the object C.

[0095] [Second embodiment] Next, an embodiment in which the measurement system 1 is used to measure the thickness of the contact strip 200 of a pantograph will be described as a second embodiment. As is known, the contact strip 200 of a pantograph is worn due to contact with a trolley wire. The thickness of the contact strip 200 changes due to the wear. Therefore, measuring the thickness of the contact strip 200 is important for the operation of a railway vehicle 5.

[0096] The measurement system 1 of the second embodiment is configured to measure the thickness H of the contact strip 200 as the object C in the same manner as in the first embodiment. The measurement system 1 of the second embodiment is similar to that of the first embodiment except that the scanning direction is adjusted according to the structure of the contact strip 200 as the object C, the reference portion P1 is set according to the structure of the contact strip 200, and the target portion P2 to be measured for the thickness H is the upper surface 210 of the contact strip 200.

[0097] Therefore, in the following, the structure of the contact strip 200, the scanning mode of the contact strip 200, and the method of adjusting the scanning direction will be mainly described as the second embodiment. 2B, a measuring device 10 fixed to a support 7 is used to irradiate a laser beam onto a slider 200 located on the upper part of the railway vehicle 5. The slider 200 moves relative to the measuring device 10 as the railway vehicle 5 moves.

[0098] Fig. 12A shows a plan view of the contact strip 200, and Fig. 12B shows a schematic A-A' cross section along the height direction of the contact strip 200. As shown in Fig. 12A, the contact strip 200 has an elongated outer shape extending in a direction along the running surface of the railway vehicle 5 and in a direction intersecting the moving direction of the railway vehicle 5, specifically in a direction perpendicular to the moving direction. The "longitudinal direction" referred to below is the elongated direction of the contact strip 200, and is a direction perpendicular to the moving direction.

[0099] 12B, the contact strip 200 includes an upper surface 210 having a contact surface 211 that comes into contact with the trolley wire and is worn, and inclined surfaces 213 and 215 that are inclined downward from the contact surface 211. The inclined surfaces 213 and 215 are located lower than the contact surface 211 and therefore do not come into contact with the trolley wire.

[0100] The inclined surfaces 213, 215 extend to the front and rear outer edges of the upper surface 210 of the contact strip 200 in the moving direction. In this embodiment, the reference position P1 is set at the tip end of the inclined surface 213. The reference position P1 is indicated by a thick line in Fig. 13. That is, the reference position P1 in this embodiment corresponds to the outer edge of the contact strip 200 extending in the longitudinal direction and located at the front in the moving direction. The reference position P1 is linear and extends in the longitudinal direction.

[0101] Since the reference portion P1 is the first to enter the irradiation range of the laser light as the railcar 5 moves, erroneous measurements occur around the reference portion P1 due to chipping of the laser light, as in the first embodiment. To suppress the effects of such erroneous measurements, the reference position Bz, which is the relative position of the reference portion P1, is calculated in the same manner as in the first embodiment.

[0102] However, the wear on the contact surface 211 of the contact strip 200 is not constant in the longitudinal direction of the contact strip 200. Therefore, it is desirable to be able to measure the thickness H of the contact strip 200 at a predetermined interval in the longitudinal direction of the contact strip 200. For example, assuming that the diameter of the contact wire is 15 mm, it is desirable to be able to measure the thickness H of the contact strip 200 at an interval of less than 5 mm in the longitudinal direction of the contact strip 200.

[0103] For this reason, in this embodiment, assuming that the sampling frequency f=15000Hz and the speed of the railway vehicle 5 is 70km / h, the scanning line for laser scanning is angled as follows. That is, the scanning line is tilted 20 degrees around the z-axis corresponding to the vertical direction from the direction (x-axis) perpendicular to the moving direction (y-axis), in other words, from the direction parallel to the sleepers. That is, the measuring instrument 10 performs laser scanning so as to irradiate the laser light on a line tilted at an angle θ of 20 degrees with respect to the x-axis. The dashed line in FIG. 12A conceptually shows the laser scanning.

[0104] When the contact strip 200 is installed at an angle θ of 20 degrees, the sampling frequency f is 15,000 Hz, and the moving speed v is 70 km / h, the measurement interval W of the relative position in the longitudinal direction is about 3 mm to 4 mm, specifically, 3.56 mm. The measurement interval W in the longitudinal direction can be calculated by the formula W tan θ = v / f using the sampling period f [Hz] and the moving speed v [m / s] of the contact strip 200.

[0105] As can be seen from this formula, the angle θ can be increased to shorten the measurement interval W in the longitudinal direction. However, since there is a limit to the scanning width of the line laser 11, if the angle θ is increased, it becomes difficult to measure the entire longitudinal direction of the contact strip 200 without omission.

[0106] The example shown in FIG. 14C shows that, because the angle θ is large, the hatched region of the long object C cannot be irradiated with laser light, and the thickness H of that region cannot be measured.

[0107] 14A, 14B, and 14C are examples of measuring the thickness H of an object C using two line lasers 11 arranged at different positions in the longitudinal direction of the object C. The dashed lines conceptually represent laser scanning. It may be understood that examples of the object C include a contact strip 200.

[0108] 14A shows that a small angle θ results in a long measurement interval W, making it impossible to measure the thickness H with sufficient distance resolution in the long direction. In this way, if the angle θ is too large or too small, there are disadvantages in terms of the lack of measurement range and distance resolution.

[0109] As shown in FIG. 14B, by setting the angle θ to an appropriate value, it is possible to measure the thickness H of the contact strip 200 (target object C) at multiple points distributed in the longitudinal direction with an appropriate distance resolution without missing any measurement range.

[0110] [Other embodiments] The present disclosure is not limited to the above-described embodiment, and can adopt various aspects. For example, erroneous measurements may occur regardless of whether the scanning line is set at an angle. Therefore, the technique of removing erroneous measurement values ​​and calculating the reference position Bz by function fitting is not limited to application to the measurement system 1 in which the scanning line is set at an angle.

[0111] Moreover, erroneous measurements may also occur due to beam chipping when the laser light is irradiated to the rear end portion located on the opposite side of the relative movement direction from the leading portion of the object C. Therefore, the technology disclosed herein is applicable even in the case where the reference portion P1 is set to the rear end portion of the object C.

[0112] For example, the reference position P1 may be set at the end P3 of the inclined surface 215 of the contact strip 200. In this case, the processor 51 reverses the order of the measurement values ​​in the data string in S130, S220, and S230, thereby eliminating erroneous measurement values ​​occurring around the rear end portion, as in the first embodiment, and calculating the reference position Bz corresponding to the rear end portion of the target C.

[0113] Furthermore, the technology of the present disclosure is applicable to various fields, not limited to the field of railway vehicles 5. In addition, the measurement of the relative position is not limited to the light section method, and the technology of the present disclosure can be applied to various measurement environments in which similar erroneous measurements may occur due to triangulation.

[0114] The function of one component in the above embodiments may be distributed among multiple components. The functions of multiple components may be integrated into one component. Part of the configuration of the above embodiments may be omitted. At least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments. All aspects included in the technical idea identified from the wording of the claims are embodiments of the present disclosure.

[0115] [Technical idea disclosed in this specification] It can be understood that the present specification discloses the following technical ideas. [Item 1] A calculation system for calculating a height of an object passing through an irradiation range of a laser beam by the measuring device, based on a relative movement of the object with respect to the measuring device caused by a movement of one of the measuring device and the object, comprising: an acquisition unit configured to acquire measurement data from the measurement device; A calculation unit configured to calculate a height of at least one target portion of the object from a reference portion of the object based on the measurement data; Equipped with the measuring instrument is configured to irradiate the laser light onto the irradiation range, receive reflected light from the object passing through the irradiation range, measure a relative position to a reflection point on the object based on a principle of triangulation, and output measurement data describing the relative position as the measurement data; the reference portion corresponds to a leading portion of the object at which the object enters the irradiation range due to the relative movement, the laser light is incident on the object, and measurement of the relative position by the measuring device is started due to reflection of the laser light on the object, or a rear end portion of the object located on the opposite side to the leading portion in the direction in which the object moves relatively; The calculation unit is determining, as an invalid measurement value, a measurement value of the relative position around the reference portion where an erroneous measurement of the relative position occurs due to the laser light being partially incident on the object in a beam diameter direction; Calculating the relative position at the reference portion as a reference position by extrapolation based on the measurement data excluding the invalid measurement values; Calculating a height of the at least one target portion from the reference portion based on a comparison between the relative position of the at least one target portion indicated by the measurement data and the reference position. A calculation system configured as follows. [Item 2] 2. The calculation system according to item 1, wherein the calculation unit determines a function corresponding to a surface shape of the object by function fitting to a group of measurement values ​​at multiple points of the object adjacent to the reference portion, excluding the invalid measurement values ​​indicated by the measurement data, and calculates the reference position based on the determined function. [Item 3] 3. The calculation system according to item 1 or 2, wherein the calculation unit determines the invalid measurement value based on a measurement period of the relative position by irradiation of the laser light, a relative speed of the object with respect to the measuring device, and the beam diameter. [Item 4] the calculation system comprises the measuring device, the relative movement of the object with respect to the measuring device is a relative movement along a predetermined travel surface; The measuring device includes, as an element for irradiating the laser light, 4. The calculation system according to any one of items 1 to 3, further comprising a line laser arranged to irradiate the laser light in a line shape in an oblique direction along the travel surface having an angle of less than 90 degrees with respect to a relative movement direction of the object with respect to the measuring device, thereby irradiating the laser light in a line shape in the oblique direction on the object. [Item 5] The object has an elongated outer shape extending in a direction along the travel surface and in a direction intersecting the direction of the relative movement, The reference portion corresponds to a linear portion extending in a longitudinal direction, the at least one target portion includes a plurality of target portions located apart in the longitudinal direction in the target object, 5. The calculation system according to item 4, wherein the oblique direction is set so that the laser light can irradiate the reference portion and the plurality of target portions during a period in which the target object moves relatively within the irradiation range. [Item 6] the object is a mount for a vehicle, 6. The calculation system according to any one of items 1 to 5, wherein the measuring device is installed on a moving path of the vehicle. [Item 7] The object is installed on a path along which a vehicle moves, The measurement device is the calculation system according to any one of items 1 to 5, which is mounted on the vehicle. [Item 8] 8. The calculation system according to item 6 or 7, wherein the vehicle is a rail vehicle. [Item 9] A computer program for causing a computer to function as the acquisition unit and the calculation unit included in the calculation system according to any one of items 1 to 8. [Item 10] A calculation method executed by a computer for calculating, by using a measuring device, a height of an object passing through an irradiation range of a laser beam by the measuring device, based on a relative movement of the object with respect to the measuring device caused by a movement of one of the measuring device and the object, the method comprising: acquiring measurement data from the measurement device; Calculating a height of at least one target portion of the object from a reference portion of the object based on the measurement data; Including, the measuring instrument is configured to irradiate the laser light onto the irradiation range, receive reflected light from the object passing through the irradiation range, measure a relative position to a reflection point on the object based on a principle of triangulation, and output measurement data describing the relative position as the measurement data; the reference portion corresponds to a leading portion of the object at which the object enters the irradiation range due to the relative movement, the laser light is incident on the object, and measurement of the relative position by the measuring device is started due to reflection of the laser light on the object, or a rear end portion of the object located on the opposite side to the leading portion in the direction in which the object moves relatively; The calculating step comprises: determining, as an invalid measurement value, a measurement value of the relative position around the reference portion where an erroneous measurement of the relative position occurs due to the laser light being partially incident on the object in a beam diameter direction; Calculating the relative position at the reference portion as a reference position by extrapolation based on the measurement data excluding the invalid measurement values; Calculating a height of the at least one target portion from the reference portion based on a comparison between the relative position of the at least one target portion indicated by the measurement data and the reference position. The calculation method includes: [Explanation of symbols]

[0116] 1...measurement system, 5...railroad vehicle, 10...measuring instrument, 11...line laser, 15...light receiving sensor, 20...detection sensor, 50...analysis device, 51...processor, 53...memory, 55...storage, 57...user interface, 59...communication interface, 200...contact strip, C...object, P1...reference portion, P2...object portion.

Claims

1. A calculation system for calculating a height of an object passing through an irradiation range of a laser beam by the measuring device, based on a relative movement of the object with respect to the measuring device caused by a movement of one of the measuring device and the object, comprising: an acquisition unit configured to acquire measurement data from the measurement device; A calculation unit configured to calculate a height of at least one target portion of the object from a reference portion of the object based on the measurement data; Equipped with the measuring instrument is configured to irradiate the laser light onto the irradiation range, receive reflected light from the object passing through the irradiation range, measure a relative position to a reflection point on the object based on a principle of triangulation, and output measurement data describing the relative position as the measurement data; the reference portion corresponds to a leading portion of the object at which the object enters the irradiation range due to the relative movement, the laser light is incident on the object, and measurement of the relative position by the measuring device is started due to reflection of the laser light on the object, or a rear end portion of the object located on the opposite side to the leading portion in the direction in which the object moves relatively; The calculation unit is determining, as an invalid measurement value, a measurement value of the relative position around the reference portion where an erroneous measurement of the relative position occurs due to the laser light being partially incident on the object in a beam diameter direction; Calculating the relative position at the reference portion as a reference position by extrapolation based on the measurement data excluding the invalid measurement values; Calculating a height of the at least one target portion from the reference portion based on a comparison between the relative position of the at least one target portion indicated by the measurement data and the reference position. A calculation system configured as follows.

2. 2. The calculation system according to claim 1, wherein the calculation unit determines a function corresponding to a surface shape of the object by function fitting to a group of measurement values ​​at multiple points of the object adjacent to the reference portion, excluding the invalid measurement values ​​indicated by the measurement data, and calculates the reference position based on the determined function.

3. The calculation system according to claim 1 , wherein the calculation unit determines the invalid measurement value based on a measurement period of the relative position by irradiation of the laser light, a relative speed of the object with respect to the measuring device, and the beam diameter.

4. the calculation system comprises the measuring device, the relative movement of the object with respect to the measuring device is a relative movement along a predetermined travel surface; The measuring device includes, as an element for irradiating the laser light, 2. The calculation system according to claim 1, further comprising a line laser arranged to irradiate the laser light in a line shape in an oblique direction along the travel surface having an angle of less than 90 degrees with respect to a relative movement direction of the object with respect to the measuring device, thereby irradiating the laser light in a line shape in the oblique direction with respect to the object.

5. The object has an elongated outer shape extending in a direction along the travel surface and in a direction intersecting the direction of the relative movement, The reference portion corresponds to a linear portion extending in a longitudinal direction, the at least one target portion includes a plurality of target portions located apart in the longitudinal direction in the target object, The calculation system according to claim 4 , wherein the oblique direction is set so that the laser light can irradiate the reference portion and the plurality of target portions during a period in which the target object moves relatively within the irradiation range.

6. the object is a mount for a vehicle, The calculation system according to claim 1 , wherein the measuring device is installed on a path along which the vehicle moves.

7. The object is installed on a path along which a vehicle moves, The calculation system according to claim 1 , wherein the measuring device is mounted on the vehicle.

8. 8. The calculation system according to claim 6, wherein the vehicle is a railroad vehicle.

9. A computer program for causing a computer to function as the acquisition unit and the calculation unit included in the calculation system according to any one of claims 1 to 7.

10. A calculation method executed by a computer for calculating, by using a measuring device, a height of an object passing through an irradiation range of a laser beam by the measuring device, based on a relative movement of the object with respect to the measuring device caused by a movement of one of the measuring device and the object, the method comprising: acquiring measurement data from the measurement device; Calculating a height of at least one target portion of the object from a reference portion of the object based on the measurement data; Including, the measuring instrument is configured to irradiate the laser light onto the irradiation range, receive reflected light from the object passing through the irradiation range, measure a relative position to a reflection point on the object based on a principle of triangulation, and output measurement data describing the relative position as the measurement data; the reference portion corresponds to a leading portion of the object at which the object enters the irradiation range due to the relative movement, the laser light is incident on the object, and measurement of the relative position by the measuring device is started due to reflection of the laser light on the object, or a rear end portion of the object located on the opposite side to the leading portion in the direction in which the object moves relatively; The calculating step comprises: determining, as an invalid measurement value, a measurement value of the relative position around the reference portion where an erroneous measurement of the relative position occurs due to the laser light being partially incident on the object in a beam diameter direction; Calculating the relative position at the reference portion as a reference position by extrapolation based on the measurement data excluding the invalid measurement values; Calculating a height of the at least one target portion from the reference portion based on a comparison between the relative position of the at least one target portion indicated by the measurement data and the reference position. The calculation method includes:

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