RU2478489C1 - Device to measure current collector height - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to electrified railroad transport. Proposed device allows simple calibration in measurement of current collector height 10a. It comprises linear sensor 20 arranged at car roof 10, computer 30 to analyse image caught by linear sensor 20 and calibration element 40 operating in the range including that of current collector displacement and having black and white regions arranged in turns in vertical direction. Said computer 30 finds approximated expression for computation the height of overhead wire. Note here that approximated expression represents relation ship between positions of said black and white regions and their actual heights 40w. Note here that positions are derived from calibration element image caught by linear sensor 20.

EFFECT: higher reliability and measurement accuracy.

30 dwg

Description

FIELD OF TECHNOLOGY

The present invention relates to a pantograph height measuring device for measuring pantograph height using image processing.

BACKGROUND OF THE INVENTION

In railway structures, fluctuations in the heights of the air wires should be within a given range of values, and the measurement of the heights of the air wires can be called as one of the elements of the inspection. The height of the air wire is equal to the height of the pantograph, which is a current collector located on the roof of the car. For this reason, traditional and well-known methods include obtaining the height of the air wire by measuring the height of the pantograph. The following can be cited, for example, as such methods for measuring pantograph height.

(A) Laser Sensor Method

This method is a method in which the pantograph height is measured by: scanning the pantograph using a laser, using a mirror or the like; and studies of the phase difference between the reflected waves, the deformation of the shape of the reflected laser, or the like.

(B) Method with light section sensor

This method is a method in which the pantograph height is measured by: projecting light in the form of strips onto a pantograph; and receiving light with zigzag stripes that correspond to the shape of the pantograph.

(C) Image Processing Method

This method is a method in which, as shown in FIG. 14, the height of the pantograph 10a is measured by: capturing an image of the pantograph 10a using a camera 20 with a linear sensor (hereinafter the linear sensor) placed on the roof of the car 10; and then performing processing, for example matching with a model or matching with a sample, on an image using a processing computer 30 (see, for example, Patent Documents 1 and 2).

Among the above methods, the image processing method is that: the position of the pixel in the image, which coincides with the previously prepared model of the pantograph 10a, is extracted from the image of the pantograph 10a captured by the linear sensor 20; then, the actual height of the pantograph 10a is calculated from the position of the pixel in the image based on the distance from the linear sensor 20 to the pantograph 10a, the focal length of the lens at the image pickup unit, and the like.

In this image processing method, the linear sensor 20 is used as an image pickup unit to increase spatial resolution and thereby improve accuracy. This method allows the device to be smaller than in the method with a laser sensor and in the method with a light section sensor, therefore leading to the advantage that the device can be installed not only on test cars made exclusively for measurement, but also on service cars.

Meanwhile, in the case of using the method in Patent Document 2, the linear sensor 20 is placed in such a position as to be turned obliquely upward, as shown in FIG. 30. In this case, the resolution is different between the pantograph 10a placed in the lower position and the pantograph 10a placed in the upper position due to the relationship between the direction of movement of the pantograph 10a and the elevation angle of the linear sensor 20. In particular, as shown in FIG. 30, the resolution is higher in the lower position and lower in the upper position. Incidentally, the reason why the resolution is higher when the pantograph 10a is in the lower position is because the pantograph 10a is closer in distance to the line sensor 20 while in the lower position.

DOCUMENTS OF KNOWN TECHNOLOGY

PATENT DOCUMENTS

Patent Document 1: Japanese Patent Application Publication No. 2006-250774

Patent Document 2: Publication of Japanese Patent Application No. 2008-104312

SUMMARY OF THE INVENTION

PROBLEMS THAT SHOULD BE SOLVED BY THE INVENTION

In the method using the line sensor 20, if the line sensor 20 is placed in front of the pantograph 10a, as indicated by the dashed line in FIG. 14, the resolution is almost constant over the image range in which the height of the air wire fluctuates. Therefore, the height of the pantograph 10a can be accurately measured. However, if the line sensor 20 is placed at the same height as the pantograph 10a, then this placement may cause contact between the line sensor 20 and the air wire 5, which can lead to a major accident.

For this reason, in the real case, the line sensor 20 is slanted downward from the pantograph 10a, as indicated by the solid line in FIG. 14. However, when the line sensor 20 is positioned as indicated by the solid line in FIG. 14, the optical axis of the linear sensor 20 intersects the movement direction (vertical direction) of the pantograph 10a diagonally, rather than perpendicularly. This leads to a state where the resolution of the pantograph 10a in the image captured by the linear sensor 20 becomes different between the pantograph 10a placed in the lower position and the pantograph 10a placed in the upper position. In particular, the resolution is higher when the pantograph 10a is in the lower position than when the pantograph 10a is in the upper position, because the pantograph 10a is closer to the linear sensor 20 while in the lower position.

For example, in Patent Document 2, the height of the pantograph 10a is calculated using a coefficient indicating the relationship between the focal length of the camera lens of the linear sensor 20, the position (pixel position) of the pantograph 10a in the image captured by the linear sensor 20, and the actual height of the pantograph 10a.

When H represents the actual height of the pantograph 10a; P is the position of the pantograph 10a in the image captured by the linear sensor 20; n is the size of the pixel; l is the distance from the linear sensor 20 to the pantograph 10a; and f is the focal length of the lens of the linear sensor 20, the ratio between them can be expressed by the following equation (1):

(1).H: P × n = l: f ...

(one).

Expanding it, we obtain the following equation (2):

(2).H = (l × P × n) / f ...

(2).

The actual pantograph height 10a is obtained using this equation (2). However, the focal length f of the lens, the distance l from the linear sensor 20 to the pantograph 10a, etc. must be measured in advance in order to perform such a calculation, and this causes a problem of poor applicability.

Additionally, if the line sensor 20 is placed at the position indicated by the dashed line in FIG. 14, the distance l from the line sensor 20 to the pantograph 10a may be kept constant. However, if the line sensor 20 is placed at the position indicated by the solid line in FIG. 14, the value of the distance l will vary from one pixel position to another in the image. Accordingly, performing a calculation with a constant distance l can cause errors in the calculation results. For this reason, when the line sensor 20 is positioned obliquely downward from the pantograph 10a, a calculation must be performed to correct the height using a projective transformation or the like. To perform this calculation, the elevation angle of the linear sensor 20 is required, and a complex calculation is necessary.

In connection with the foregoing, the purpose of the present invention is to provide a pantograph height measuring device that enables easy calibration when measuring the pantograph height.

MEANS FOR SOLVING PROBLEMS

The pantograph height measuring apparatus in accordance with the first invention for solving the above problems includes a linear sensor and image processing means, and measures the height of the pantograph on a car that is moving, while the linear sensor is placed on the car roof and the image processing means is configured for image analysis, Captured by a linear sensor. The pantograph height measuring device is characterized in that: a calibration element on which dark-colored regions and light-colored regions are alternately arranged in a vertical direction is detachably provided in a range including the pantograph's range of movement; and the image processing means is configured to obtain an expression of a relationship representing the relationship between the positions of the dark areas and light areas in the image and the actual heights of the dark areas and light areas, and calculating the actual pantograph height from the pantograph position in the image that is captured by the linear sensor, using a relationship expression, wherein the positions of the dark areas and light areas are obtained from the image of the calibration element nt captured by the linear sensor.

The pantograph height measuring device in accordance with the second invention for solving the above problems is a pantograph height measuring device in accordance with the first invention, characterized in that: an image capturing line adjustment element having a plurality of first color areas combined in a vertical direction and second color areas located around areas of the first color, is provided detachably to the calibration element; the pantograph height measuring device comprises display means for displaying an image captured by a linear sensor; and the shapes of the first color areas in the image capturing line adjustment element are set so that the widths of the first color areas and the second color areas shown on the display means change depending on the position and the slope of the image capturing line in the linear sensor.

The pantograph height measuring device in accordance with the third invention for solving the above problems is a pantograph height measuring device in accordance with the second invention, characterized in that regions of the first color are formed having a vertical width more in the horizontal center than on both sides of the horizontal center so that areas of the first color are in contact with neighboring areas of the first color in the horizontal center of the image capturing line adjustment element.

A pantograph height measuring device in accordance with the fourth invention for solving the above problems is a pantograph height measuring device in accordance with any of the first to third inventions, characterized in that the image processing means includes: an input image creating unit for creating an input image by arranging in chronological order of image signals input from a linear sensor; a binarization unit for creating a binary image by converting the input image to binary form; a colored area position detecting unit for detecting positions of dark areas and light areas in a binary image; and an arithmetic relationship expression unit for finding a relationship expression based on the positions of the dark color areas and light color areas in the binary image and the actual positions of the dark color areas and light color areas.

The pantograph height measuring apparatus according to the fifth invention for solving the above problems is a pantograph height measuring apparatus according to the second invention, characterized in that the image capturing line adjustment element includes a center line in the horizontal center of the image capturing line correction element.

The calibration method for the pantograph height measuring device in accordance with the sixth invention for solving the above problems is a calibration method for the pantograph height measuring device which is configured to capture a pantograph image on a car that is moving by a linear sensor placed on the car roof and measure the pantograph height by analyzing the image captured by the linear sensor. The calibration method is characterized in that it comprises: a first step of placing the calibration element in the vicinity of the pantograph, wherein the calibration element has dark areas and light areas located alternately on its surface in a vertical direction; a second step of capturing an image of the calibration element using a linear sensor; and a third step for causing the image processing means to detect the positions of the dark areas and light areas in the image captured by the linear sensor, and to determine a relationship expression representing the relationship between the detected positions of the dark areas and light areas in the image and the actual positions of the dark areas and areas light color.

The calibration method for the pantograph height measuring device in accordance with the seventh invention is a calibration method for the pantograph height measuring device in accordance with the sixth invention, characterized in that: the image capturing line adjustment element is arranged on the calibration element, wherein the image capturing line correction element has several areas the first color of the same shape, which are combined together in a vertical direction, and areas of the second color are located around areas of the first color, the regions of the first color and the regions of the second color being arranged so that the widths of the regions of the first color and the regions of the second color shown on the display means change depending on the position and the slope of the image capturing line in the linear sensor; the image of the image capturing line adjustment element is captured by a linear sensor; the image capturing line is adjusted when checking the image of the image capturing line adjustment element shown on the display means for displaying an image captured by the linear sensor; the image capturing line adjustment element is separated; and after that the first, second and third stages are performed.

The calibration method for the pantograph height measuring device in accordance with the eighth invention to solve the above problems is a calibration method for the pantograph height measuring device in accordance with the seventh invention, characterized in that in the image capturing line adjustment element, regions of the first color are formed having a vertical width larger in horizontal center than on both sides of the horizontal center, so that areas of the first color are in contact with neighboring areas a first color in the horizontal center of the image capturing element line corrections.

The calibration method for the pantograph height measuring device in accordance with the ninth invention for solving the above problems is the calibration method for the pantograph height measuring device in accordance with any of the sixth to eighth inventions, characterized in that the image processing means: creates an input image by ordering in chronological order the order of the image signals input from the linear sensor; creates a binary image by converting the input image to binary form; detects the positions of areas of dark color and areas of light color in a binary image; and determines a relationship expression based on the positions of the dark color areas and the light color areas in the binary image, as well as the actual positions of the dark color areas and light color areas.

The calibration method for the pantograph height measuring device in accordance with the tenth invention is a calibration method for the pantograph height measuring device in accordance with the sixth invention, characterized in that the middle line is provided in the horizontal center of the image capturing line adjustment element and the image capturing line is adjusted based on the middle line .

SUMMARY OF THE INVENTION

The pantograph height measuring device in the first invention is a pantograph height measuring device including a linear sensor placed on a car roof and image processing means for analyzing an image captured by a linear sensor and configured to measure a pantograph height on a car that is moving. The pantograph height measuring device is designed in such a way that: a calibration element on which dark-colored areas and light-colored areas are arranged alternately in the vertical direction is detachably in a range including the pantograph's range of movement; and the image processing means is configured to obtain an expression of a relationship representing the relationship between the positions of the dark areas and light areas in the image and the actual heights of the dark areas and light areas, and calculating the actual pantograph height from the pantograph position in the image that is captured by the linear sensor, using a relationship expression, wherein the positions of the dark areas and light areas are obtained from the image of the calibration element nt captured by the linear sensor. Thus, by analyzing the captured image of the calibration element, a relationship expression representing the relationship between the positions of the dark areas and light areas in the image and the actual heights of the dark areas and light areas can be easily obtained independently of the operator, without worrying about the focal length of the lens cameras in a linear sensor, the distance from the linear sensor to the pantograph, the image resolution, the elevation angle of the linear sensor, etc., while uchaetsya from a captured image of the calibration element. Accordingly, even if the images need to be captured using a linear sensor facing obliquely upward, the accuracy in measuring the height of the pantograph can be improved without performing complex calculations.

According to the pantograph height measuring device in the second invention, an image capturing line adjustment element having a plurality of first color regions combined in the vertical direction and second color regions located around the first color regions is detachably connected to the calibration element; the pantograph height measuring device comprises display means for displaying an image captured by a linear sensor; and the shapes of the first color areas in the image capturing line adjustment element are set so that the widths of the first color areas and the second color areas shown on the display means change depending on the position and the slope of the image capturing line in the linear sensor. Thus, in addition to the useful result of the first invention, the position and orientation of the image pickup line in the linear sensor can be adjusted simply and reliably so that the image pickup line can be perpendicular to the pantograph. Accordingly, the pantograph height can be measured very accurately.

According to the pantograph height measuring apparatus according to the third invention, in the image capturing line adjustment element, regions of the first color are formed having a vertical width larger in the horizontal center than on both sides of the horizontal center so that regions of the first color are in contact with adjacent regions of the first color in the horizontal center Image capture line adjustment element. Thus, so that the image capture line is perpendicular to the pantograph, it is sufficient that the position and the slope of the image capture line are adjusted so that areas of the first color are displayed on the display means as a continuous area. Accordingly, the position and inclination of the image capturing line can be easily corrected.

According to a pantograph height measuring apparatus in the fourth invention, the image processing means includes: an input image creating unit for creating an input image by chronologically ordering image signals input from a linear sensor; a binarization unit for creating a binary image by converting the input image to binary form; a colored area position detecting unit for detecting positions of dark areas and light areas in a binary image; and an arithmetic relationship expression unit for finding a relationship expression based on the positions of the dark color areas and light color areas in the binary image and the actual positions of the dark color areas and light color areas. Thus, it is possible to calmly perform processing to obtain an expression of a relation representing the relationship between the position of the dark color regions and the light color regions in the image and the actual heights of the dark color regions and the light color regions, wherein the positions are obtained from the captured image of the calibration element.

According to the pantograph height measuring apparatus according to the fifth invention, the image capturing line adjustment element includes a center line in the horizontal center of the image capturing line correction element. Thus, it is possible to objectively determine whether the direction in which the linear sensor is rotated is suitable for adjusting the slope of the image capturing line. In addition, adjustments can be made when viewing the captured image without worrying about the actual rotation and horizontal movement of the linear sensor. In addition, adjustments can be made in a simple and universal way without the need for any operator perception or experience. In addition, as calibration accuracy increases, the height of the pantograph can be accurately measured.

A calibration method for a pantograph height measuring device in accordance with a sixth invention is a calibration method for a pantograph height measuring device that is configured to capture a pantograph image on a car that is moving by a linear sensor placed on the roof of the car and measure the pantograph height by analyzing the image, Captured by a linear sensor. The calibration method includes: the first stage of placing the calibration element in the vicinity of the pantograph, and the calibration element has areas of dark color and areas of light color, located alternately on its surface in the vertical direction; a second step of capturing an image of the calibration element using a linear sensor; and a third step for causing the image processing means to detect the positions of the dark areas and light areas in the image captured by the linear sensor, and to determine a relationship expression representing the relationship between the detected positions of the dark areas and light areas in the image and the actual positions of the dark areas and areas light color. Thus, by analyzing the captured image of the calibration element, it is easy to calculate a relationship expression representing the relationship between the positions of the dark areas and light areas in the image and the actual heights of the dark areas and light areas, regardless of the operator and not caring about the focal length the lens of the camera in a linear sensor, the distance from the linear sensor to the pantograph, image resolution, the elevation angle of the linear sensor, etc., while dix obtained from a captured image of the calibration element. Accordingly, even if the images need to be captured using a linear sensor facing obliquely upward, the accuracy in measuring the height of the pantograph can be improved without performing complex calculations.

According to a calibration method for the pantograph height measuring device in the seventh invention, the image capturing line adjustment element is arranged on the calibration element, the image capturing line correction element having several regions of a first color of the same shape that are combined together in a vertical direction and regions of a second color are arranged around areas of the first color, and areas of the first color and areas of the second color are arranged so that the widths of the areas of the first areas of color and the second color shown on the display means vary depending on the position and inclination of the image capturing line in the line sensor; the image of the image capturing line adjustment element is captured by a linear sensor; the image capturing line is adjusted when checking the image of the image capturing line adjustment element shown on the display means for displaying an image captured by the linear sensor; the image capturing line adjustment element is separated; and after that the first, second and third stages are performed. Thus, in addition to the useful result of the fifth invention, the position and orientation of the image pickup line in the linear sensor can be adjusted simply and reliably so that the image pickup line can be perpendicular to the pantograph. Accordingly, the pantograph height can be measured very accurately.

According to the calibration method for the pantograph height measuring device in the eighth invention, in the image capturing line adjustment element, regions of the first color are formed having a vertical width greater in the horizontal center than on both sides of the horizontal center, so that the regions of the first color are in contact with neighboring regions of the first colors in the horizontal center of the image capturing line adjustment item. Thus, so that the image capture line is perpendicular to the pantograph, it is sufficient that the position and the slope of the image capture line are adjusted so that areas of the first color are displayed on the display means as a continuous area. Accordingly, the position and inclination of the image capturing line can be easily corrected.

According to a calibration method for a pantograph height measuring device in the ninth invention, the image processing means: creates an input image by arranging in chronological order the image signals input from the linear sensor; creates a binary image by converting the input image to binary form; detects the positions of areas of dark color and areas of light color in a binary image; and determines a relationship expression based on the positions of the dark color areas and the light color areas in the binary image, as well as the actual positions of the dark color areas and light color areas. Thus, it is possible to calmly perform processing to obtain an expression of a relationship representing the relationship between the position of the dark color regions and the light color regions in the image, as well as the actual heights of the dark color regions and the light color regions, wherein the positions are obtained from the captured image of the calibration element.

According to the calibration method for the pantograph height measuring device in the tenth invention, a middle line is provided in the horizontal center of the image capturing line adjustment element, and the image capturing line is adjusted based on this middle line. Thus, it is possible to objectively determine whether the direction in which the linear sensor is rotated is suitable for adjusting the slope of the image capturing line. In addition, adjustments can be made when viewing the captured image without worrying about the actual rotation and horizontal movement of the linear sensor. In addition, adjustments can be made in a simple and universal way without the need for any operator perception or experience. In addition, as calibration accuracy increases, the height of the pantograph can be accurately measured.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram showing an exemplary application of a pantograph height measuring device in Embodiment 1 of the present invention.

FIG. 2 is an explanatory diagram showing an example of a calibration element in Embodiment 1 of the present invention.

FIG. 3 is a block diagram showing a schematic structure of a processing computer in Embodiment 1 of the present invention.

FIG. 4 is a flowchart showing processing to be performed by a processing computer in Embodiment 1 of the present invention.

FIG. 5 is an explanatory diagram showing an example of a calibration image obtained in Embodiment 1 of the present invention.

FIG. 6 is an explanatory diagram showing an example of a binary image obtained in Embodiment 1 of the present invention.

FIG. 7 is a graph showing a relationship between a pixel position of a contact wire and an actual height obtained in Embodiment 1 of the present invention.

Part (a) of FIG. 8 is a front view of an image capturing line adjustment element in Embodiment 2 of the present invention. Part (b) of FIG. 8 is a side view of the image capturing line adjustment element shown in part (a) of FIG. 8.

FIG. 9 is a flowchart showing processing related to adjusting an image capturing line in Embodiment 2 of the present invention.

Parts (a), (b) and (c) of FIG. 10 are explanatory diagrams showing exemplary positions of an image capturing line on an image capturing line adjustment element in Embodiment 2 of the present invention.

Parts (a), (b) and (c) of FIG. 11 are explanatory diagrams showing exemplary calibration images obtained from the positions of the image pickup line shown in parts (a), (b) and (c) of FIG. 10.

Parts (a), (b) and (c) of FIG. 12 are explanatory diagrams showing exemplary positions of an image pickup line on a calibration element in Embodiment 1 of the present invention.

Parts (a) and (b) of FIG. 13 are explanatory diagrams showing other examples of an image capturing line adjustment element.

FIG. 14 is an explanatory diagram showing examples of arrangement of a linear sensor.

FIG. 15 is a front view of the image capturing line adjustment elements in Embodiment 3 of the present invention.

FIG. 16 is a schematic diagram showing a configuration of a device used in an adjustment method using an image capturing line adjustment element in Embodiment 3 of the present invention.

FIG. 17 is a flowchart showing an example of a configuration used in an adjustment method using an image capturing line adjustment element in Embodiment 3 of the present invention.

FIG. 18 is a flowchart showing an adjustment method using an image capturing line adjustment element in Embodiment 3 of the present invention.

FIG. 19 is a diagram showing an example of a captured image that is visible before horizontal adjustment is performed in Embodiment 3 of the present invention.

FIG. 20 is a diagram showing an example of a captured image that is visible after horizontal adjustment is performed in Embodiment 3 of the present invention.

FIG. 21 is a diagram showing an example of a captured image that is visible after rotational adjustment is performed in Embodiment 3 of the present invention.

FIG. 22 is a diagram showing an example of a captured image that is visible after adjustments are made in Embodiment 3 of the present invention.

FIG. 23 is a diagram showing an example of an image capturing line that has not yet been horizontally adjusted in Embodiment 3 of the present invention.

FIG. 24 is a diagram showing an example of an image capturing line on which horizontal adjustment is performed in Embodiment 3 of the present invention.

FIG. 25 is a diagram showing an example of an image capturing line that has been rotationally adjusted in Embodiment 3 of the present invention.

FIG. 26 is a diagram showing an example of an image capturing line on which corrections are made in Embodiment 3 of the present invention.

FIG. 27 is a diagram showing examples of patterns in correction elements of an image capturing line for a linear sensor in Embodiments 1 and 2 of the present invention.

FIG. 28 is a diagram showing examples of conditions for capturing images of correction elements of the image capturing line in Embodiments 1 and 2 of the present invention.

FIG. 29 is a diagram showing examples of how images of correction elements of the image capturing line are captured in Embodiments 1 and 2 of the present invention.

FIG. 30 is a schematic view showing an example of the placement of a linear sensor according to Patent Document 2.

BEST MODES FOR CARRYING OUT THE INVENTION

Below, some examples of the pantograph height measuring device of the present invention will be described in detail with reference to the drawings.

Option 1 implementation

A first embodiment of the pantograph height measuring apparatus of the present invention will be described using FIG. 1 to 7. FIG. 1 is a schematic configuration diagram of a pantograph height measuring apparatus of this embodiment. FIG. 2 is a front view of a calibration element in this embodiment. FIG. 3 is a block diagram showing the structure of a pantograph height measuring device in this embodiment. FIG. 4 is a flowchart showing a calibration sequence performed by the pantograph height measuring apparatus in this embodiment. FIG. 5 is an explanatory diagram showing an example of a calibration image in this embodiment. FIG. 6 is an explanatory diagram showing an example of a binary image. FIG. 7 is a graph showing a relationship between an actual height and a pixel position in an image.

As shown in FIG. 1, the pantograph height measuring device in this embodiment includes a line sensor 20, a processing computer 30, and a calibration element 40.

The line sensor 20 is located on the roof of the car 10 so as to capture images of the pantograph 10a. In particular, the orientation of the linear sensor 20 is set so that: its optical axis can be directed obliquely upward; and its scan line direction could be orthogonal to the pantograph 10a. The image signals obtained by this linear sensor 20 are input to the processing computer 30.

The processing computer 30 has the function of obtaining an approximate expression for calculating the height of the air wire, the approximate expression being an expression representing the relationship between the position of the calibration element 40 in the image captured by the linear sensor 20 and the actual position of the calibration element 40. As shown in FIG. 3, the processing computer 30 includes an input image creating unit 31, a binarization unit 32, a pixel width extraction unit 33 as a colored area position detecting unit, an approximate expression arithmetic unit 34 as an arithmetic ratio expression unit, and storage devices 35A, 35B. In addition, the monitor 60, configured to display the calibration image 1 (image from the linear sensor) and binary image 2, which are described below, is connected to the processing computer 30.

In the configuration, in order to find an approximate expression for calculating the height of the air wire, the input image creating unit 31 creates a calibration image 1 (see FIG. 5) by arranging in chronological order the image signals obtained by capturing images of the calibration element 40 and input from the linear sensor 20. This the calibration image 1 is sent to the binarization unit 32 through the storage devices 35A, 35B.

The binarization unit 32 creates a binary image 2 (see FIG. 6) by binary conversion of the calibration image 1 input from the input image creating unit 31. The binary image 2 created by this binarization unit 32 is sent to the pixel width extraction unit 33 via the storage device 35B.

The pixel width extraction unit 33 extracts a trace 2b of each black region 40b and a trace 2w of each white region 40w of the calibration element 0, which will be described later, from the binary image 2 input from the binarization block 32, and accordingly obtains the width of each of the regions 2b, 2w in as a pixel width. Information about the widths of pixels extracted by the pixel width extraction unit 33 is sent to the arithmetic unit 34 of the approximate expression through the storage device 35B.

The approximate expression arithmetic unit 34 obtains an approximate expression for calculating the height of the air wire using the least square method based on the pixel widths input from the pixel width extraction unit 33 and the actual widths of the black areas 40b and the white areas 40w, which are measured in advance. An approximate expression for calculating the height of the air wire, which is found by the arithmetic unit 34 of the approximate expression, is stored in the storage device 35B.

In this regard, the least squares method is a method in which, when a certain function, such as a linear function or a logarithmic curve, which can be assumed from a suitable model, is designed to approximate a set of numerical values obtained by measurement, a coefficient that minimizes the sum of the residual squares is determined so that the original function can best approach the measured values.

Using the above configuration, the processing computer 30 allows: analysis of image signals input from the linear sensor 20; and finding an approximate expression for calculating the height of the air wire.

The calibration element 40 is made of a leaf-shaped element formed in the form of, for example, a rectangle. This calibration element 40 is formed so that its longitudinal length is greater than the range of movement of the pantograph, that is, the range of oscillation of the air wire. In addition, this calibration element 40 is detachably fixed in a position in the vicinity of one of the end surfaces of the pantograph 10a, which is closest to the linear sensor 20. In particular, the calibration element 40 is detachably fixed in a position in which there should be no error in the heights of the calibration element 40 and pantograph 10a obtained using the processing computer 30. Additionally, the calibration element 40 is placed at a height that includes the range of oscillation of the air wire.

As shown in FIG. 2, the black regions 40b and the white regions 40w are alternately arranged on the surface of the calibration element 40 in its longitudinal direction. In this embodiment, the black regions 40b and the white regions 40w have the same width (L) and the boundaries between the black regions 40b and the white regions 40w are perpendicular to the longitudinal direction of the calibration element 40.

Based on FIG. 4, processing will be described to find an approximate expression for calculating the height of the air wire using the pantograph height measuring device in this embodiment.

The calibration element 40 is located in the vicinity of the pantograph 10a, and the line sensor 20 is prompted to start capturing images of the calibration element 40. In doing this, as shown in FIG. 4, the processing computer 30 arranges in chronological order the images of the calibration element 40 input from the linear sensor 20, and accordingly creates the calibration image 1, which is shown in FIG. 5 (step PA1). As shown in FIG. 5, in the calibration image 1, traces 1b of black areas 40b and traces 1w of white areas are displayed.

In this regard, since the optical axis of the linear sensor 20 is directed obliquely upward, the uppermost region of the calibration element 40, which extends the distance from the linear sensor 20 to the calibration element 40, is displayed in the calibration image 1 with a width WH less than the width WL from which the region is displayed a calibration element 40, which shortens the distance from the linear sensor 20 to the calibration element 40.

After step PA1, the calibration image 1 is converted to binary form and a binary image 2 is created, which is shown in FIG. 6 (step PA2). As shown in FIG. 6, binary image 2 is an image that is almost the same as calibration image 1.

After step PA2, traces 2b and 2w corresponding to the black and white regions 40b and 40w, respectively, are extracted from the binary image 2, and then their widths are obtained (in this embodiment, the distances p1 to p6 from one to the other boundaries between adjacent tracks 2b and 2w as shown in Fig. 6) (step PA3).

After that, as shown in FIG. 7, a relationship is obtained between the widths p1 to p6 obtained in step PA3 and the actual positions of the black and white areas 40b, 40w in the calibration element 40 (in this embodiment, the distances L to 6L from one to the other borders between adjacent black and white areas 40b, 40w). Based on this ratio and the image captured by the linear sensor 20, an approximate expression for calculating the height of the air wire as an expression of the ratio for calculating the height of the pantograph 10a, i.e. the height of the air wire, is obtained by the least squares method (step PA4). An approximate expression for calculating the height of the air wire can be obtained through the above processing.

It should be noted that in the case of measuring the height of the pantograph 10a using an approximate expression for calculating the height of the air wire, first of all, the pixel position of the pantograph 10a in the captured image is obtained by image processing, for example, matching with a sample, as in the case disclosed in Patent Document 2. Then the obtained pixel position is replaced by the corresponding variable in the approximate expression obtained in step PA4. Therefore, the height of the pantograph 10a can be accurately obtained even when the optical axis of the linear sensor 20 is obliquely directed. Note that obtaining the actual height of the overhead wire requires adding height from the ground to the calibration element 40 as an offset.

An appropriately configured pantograph height measuring device in this embodiment allows any operator to perform a calibration because the device allows an approximate expression to be calculated for calculating the wire height by analyzing captured images of the calibration element 40, regardless of the focal length of the camera lens in the linear sensor, the distance from the linear sensor to pantograph, image resolution, etc.

Accordingly, even when images are captured with the optical axis of the linear sensor 20 directed obliquely upward, the height of the pantograph 10a can be measured very accurately without performing any complex calculations that take into account the distance from the linear sensor 20 to the pantograph 10a, the elevation angle of the camera, etc. P.

Option 2 implementation

A second embodiment of the pantograph height measuring apparatus of the present invention will be described using FIG. 8 to 13. Part (a) of FIG. 8 is a front view of an image capturing line adjustment element used in this embodiment. Part (b) of FIG. 8 is a side view of the image capturing line adjustment element shown in part (a) of FIG. 8. FIG. 9 is a flowchart showing a processing sequence for correcting a position of a linear sensor in this embodiment. Parts (a), (b) and (c) of FIG. 10 are explanatory diagrams showing exemplary positions of an image capturing line on an image capturing line adjustment element. Parts (a), (b) and (c) of FIG. 11 are explanatory diagrams showing exemplary calibration images corresponding to FIG. 11. FIG. 12 is an explanatory diagram showing exemplary positions of an image pickup line on a calibration element in Embodiment 1 of the present invention. Parts (a) and (b) of FIG. 13 are front views showing other examples of an image capturing line adjustment element.

This embodiment is an example where the image capturing line adjustment element 50 shown in FIG. 8 is used to adjust the image pickup line in the linear sensor before the calibration action described in Embodiment 1 is performed. Since the rest of the configuration is almost the same as in Embodiment 1, the same elements are denoted by the same reference numbers and their identical description will be omitted. A description will be given mainly about what distinguishes the second embodiment from the first embodiment.

In Embodiment 1, as shown in part (a) of FIG. 12, the image pickup line S in the linear sensor 20 is set perpendicular to the pantograph 10a, that is, in a manner that enables image capture of the calibration element 40 in the longitudinal direction. With the linear sensor 20 arranged in this way, the most ideal and more accurate calibration can be performed.

In contrast, in the case where the line sensor 20 is arranged with an image pickup line S intersecting both edges along the width of the calibration element 40, as shown in part (b) of FIG. 12, it is likely that it is not possible to obtain an exact approximate expression for calculating the height of the air wire because the traces corresponding to the parts of the calibration element 40 indicated by circles from the dashed lines in part (b) of FIG. 12 appear in calibration image 1 with pixel widths less than otherwise.

Even in the case where the image pickup string S does not cross the edges across the width of the calibration element 40, as shown in part (c) of FIG. 12, if the image pickup line S is inclined at an angle θ to the longitudinal direction of the calibration element 40, then the width Wpc of each white area 40w on the image pickup line S shown in part (c) of FIG. 12 is (1 / cosθ) times larger than the width Wpa of each white region 40w on the image pickup line S shown in part (a) of FIG. 12. Hence the resolution corresponding to the image capturing line S shown in part (c) of FIG. 12 is made equal to (L / P) cosθ, which is cosθ greater than the L / P resolution corresponding to the image capturing line S shown in part (a) of FIG. 12.

In this regard, when the angle θ changes, for example, by 1 or 2 degrees, the value of cosθ is still approximately 1, and therefore, sufficient accuracy can be ensured. However, since the image pickup elements of the linear sensor 20 are located on the same line and it captures one-dimensional images, it is difficult to calculate from the image shown on the monitor 60 which part of the calibration element 40 is captured by the linear sensor 20, and how much the linear sensor 20 is inclined relative to the longitudinal directions of the calibration element 40. For this reason, a complex action may be required to make the image pickup line S of the linear sensor 20 parallel to the longitudinal one board calibration element 40.

To find a way out of this, this embodiment is configured to use the aforementioned image capturing line adjustment element 50 shown in FIG. 8 to correct the slope of the image pickup line of the line sensor 20.

In particular, as shown in FIG. 8, in this embodiment, the image capturing line adjustment element 50 is detachably attached to a side surface of the calibration element 40 facing the linear sensor 20. The image capturing line correction element 50 is made of a sheet-like element formed in the form of a rectangle. On its surface, several (four in FIG. 8) black regions 50a as regions of the first color are combined on the surface of the calibration element 50 in a straight line stretching in the vertical direction. In addition, white areas 50b as regions of the second color are arranged around black areas 50a. Each black region 50a is in the form of a rhombus and is in contact with an adjacent element (s) 50 adjusting the image capturing line at opposite angles.

Based on FIG. 9, a description will be given of the sequence in which the pantograph height measuring device in this embodiment corrects the image capturing line in the line sensor 20. As shown in FIG. 9, in the case of adjusting the position of the image pickup line in the linear sensor 20 in this embodiment, first of all, the image pickup line adjusting element 50 is attached to the calibration element 40 so that the direction in which the black areas 50a are combined coincides with the center of the width of the calibration element 40 (step PB1).

Then, the image of the image capturing line adjustment element 50 is captured by the linear sensor 20 and displayed on the monitor 60 (step PB2). Generally speaking, in this case, one of the images shown in parts (a), (b) and (c) of FIG. 11 is displayed on the monitor 60. Note that the image pickup line S in the linear sensor 20 deviates from the center o if black and white areas appear alternately in the image, as shown in part (a) or (b) of FIG. 11. On the other hand, the image capturing line S coincides with the center of the image capturing line adjustment element 50 if the colored areas of the same color are displayed as a continuous area, as shown in part (c) of FIG. eleven.

Then, the position of the image capturing line is adjusted (step PB3). In particular, if the image is captured in a position that leads to the location of the image capturing line S in the linear sensor 20, which is shown in part (a) of FIG. 10, an image is displayed on the monitor 60, which is shown in part (a) of FIG. 11, that is, an image in which each black region 50b and each white region 50w have respective equal widths. In this case, since the image pickup line in the linear sensor 20 is parallel but outside the center o, the image pickup line S can be corrected by shifting the orientation of the linear sensor 20 horizontally while checking the image shown on the monitor 60. Incidentally, the orientation of the linear sensor 20 should shift in such a direction that the shift leads to an increase in the widths of the black areas 50a shown on the monitor 60.

In addition, if the image is captured at a position that results in the location of the image capturing line S in the line sensor 20, which is shown in part (b) of FIG. 10, an image is displayed on the monitor 60, which is shown in part (b) of FIG. 11, that is, an image in which the black and white regions 50b, 50w have correspondingly different widths. In this case, the image pickup line S in the linear sensor 20 is inclined with respect to the center o. For this reason, when checking the image shown on the monitor 60, the image pickup line S in the linear sensor 20 should be moved so that it becomes parallel to the center o, using: first of all, turning the image pickup line in the linear sensor 20 to such an extent that the black widths areas 50a become almost equal and the widths of white areas with the same success become almost equal; and subsequently moving the linear sensor 20 horizontally.

As a result of this adjustment of the image capturing string S, as shown in part (c) of FIG. 11, black areas 50a (or white areas) can be displayed respectively as a continuous area, the position and orientation of the image capturing line S can be adjusted to align with the center of the image capturing line adjustment element 50.

After adjusting the image capturing line S in the linear sensor 20, the image capturing line adjustment element 50 is disconnected from the calibration element 40 (step PB4), and then the calibration processing described in Embodiment 1 (step PB5) is performed.

Due to the configuration described above, the pantograph height measuring device in this embodiment allows any operator to easily perform the action of bringing the image pickup line in the linear sensor 20 to coincide with the center of the calibration element 40.

In addition, since calibration can be performed with the image pickup line S in the linear sensor 20 coinciding with the center o of the calibration element 40, the height of the pantograph 10a can be measured very accurately.

It should be noted that, although as the aforementioned embodiment, a moment is shown where the image pickup line adjustment element 50 has diamond-shaped black areas 50b against the background of white areas 50w, the white areas 51w may have a diamond shape against the background of black areas 51b, as in the case of the element 51 adjustments to the image capturing line shown in part (a) of FIG. 13. In addition, the shape of each region of the first color is not limited to the shape of the rhombus. It is sufficient that the vertical width in its horizontal center is greater than the vertical widths of both sides of the center, as in the case of the image capturing line adjustment element 52 shown in part (b) of FIG. 13, wherein the first color regions 52b are elliptical in shape each and their surroundings are the second color regions 52w. Of course, various changes can be made within the scope, without deviating from the essence of the present invention.

Option 3 implementation

As mentioned previously, in the case of using the method in Patent Document 2, the line sensor 20 is positioned to be angled upward as shown in FIG. 30. In this case, the resolution is different between the pantograph 10a placed in the lower position and the pantograph 10a placed in the upper position due to the relationship between the direction of movement of the pantograph 10a and the elevation angle of the linear sensor 20. In particular, as shown in FIG. 30, the resolution is higher in the lower position and lower in the upper position. Incidentally, the reason why the resolution is higher when the pantograph 10a is in the lower position is because the pantograph 10a is closer in distance to the line sensor 20 while in the lower position.

Calibration methods that are described in Embodiments 1 and 2 are proposed to solve the aforementioned resolution difference. Embodiments 1 and 2 enable calibration to be performed automatically by: capturing images of the calibration element 40 using a linear sensor 20; and exposing those images to image processing.

However, Embodiments 1 and 2 require adjustment of the image pickup line in the line sensor 20 during calibration. The image capturing line adjustment element 50, which is shown in FIG. 27 is used to adjust the image pickup line in the linear sensor 20. As indicated by reference number 50L in part (a) of FIG. 27, the vertices of the rectangles are aligned in a straight line. Therefore, the part corresponding to the image capturing line adjustment element 50 will become completely black in the captured image if the image capturing line in the linear sensor 20 coincides with a straight line. Then, adjustment is performed along with checking the widths of black and white areas, etc. in the captured image so that the portion of the image that corresponds to the image capturing line adjustment element 50 can turn black. Incidentally, as shown in part (b) or (c) of FIG. 27, black and white tones can be interchanged, or circles can be used instead of rectangles.

In the case of using the image capturing line adjustment element 50 in part (a) of FIG. 27 for making adjustments, as shown in part (a) of FIG. 29, white areas will be displayed with uneven widths if the image is captured diagonally, as indicated by S in part (a) of FIG. 28. The linear sensor 20 is rotated either clockwise or counterclockwise to such an extent that the widths of the white areas become even, as shown in part (b) of FIG. 29 to set the image pickup line in the linear sensor parallel to the center line 50Lc in part (a) of FIG. 27.

The widths do not actually become even, because the line sensor 20 is angled upward. The tilt of the linear sensor 20 is adjusted so that the widths of the white areas become smaller in the right direction (the widths of the white areas become larger in the right direction depending on the image capture line). Remaining in this state, the linear sensor 20 moves horizontally to adjust the linear sensor 20 in such a direction that horizontal movement increases the width of the black areas. The correction of the image capturing line is completed as soon as the part in the captured image that corresponds to the image capturing line adjusting element 50 ultimately becomes completely black, as shown in part (c) of FIG. 29.

Although the image capturing line can be corrected using the above method, the adjustment can be performed more efficiently if the methods below are available:

(1) a method that allows an objective determination of whether the direction in which the linear sensor 20 is rotated is suitable for adjusting the slope of the image capturing line;

(2) a method that allows adjustment when viewing a captured image without worrying about the actual rotation and horizontal movement of the linear sensor 20; and

(3) a correction method that does not require operator perception or experience and is more universal.

In connection with the foregoing, the pantograph height measuring device and its calibration method in this embodiment are configured so that in addition to the results of the methods in Embodiments 1 and 2, the adjustment of the image capture line can be performed more efficiently when viewing the captured image without the need for perception or operator experience during calibration performed to measure the height of the pantograph 10a using the linear sensor 20.

The configuration of the pantograph height measuring device in this embodiment will be described below. FIG. 15 is a front view of adjustment elements of an image capturing line in this embodiment. As shown in part (a) of FIG. 15, the image capturing line adjustment element 100 in the pantograph height measuring device in this embodiment has a pattern with a white center line 101 in a portion representing the image capturing target line.

Note that the pattern in the image capturing line adjustment element 100 is not limited to the pattern shown in part (a) of FIG. 15. The template may be a template, which is shown in part (b) of FIG. 15, in which black and white tones are inverted, or with the pattern shown in part (c) of FIG. 15, in which circles are used instead of rectangles. In addition, the white parts of the image capturing line adjustment element 100 are made of high reflectivity material, while its black parts are made of low reflectivity material.

FIG. 16 is a schematic diagram showing a configuration of a device used in an adjustment method using an image capturing line adjustment element in this embodiment. As shown in FIG. 16, the image capturing line adjustment element 100 is attached to the pantograph 102. Note that FIG. 16 shows a side projection of an image capturing line adjustment element 100. The linear sensor 103 is placed on a stand 104 that allows horizontal movement and rotation so that the position and orientation of the linear sensor 103 can be adjusted. Note that any means can be used instead of the stand 104 provided that it allows rotation without changing the center of rotation.

A line sensor 103 placed on the stand 104 is located on the roof of the car 105 to capture images of the image capturing line adjustment element 100. In addition, the lamp 106 is located near the linear sensor 103 so that images of black and white patterns on the image capturing line adjustment element 100 can be captured in a dark environment, for example at night, inside a tunnel or in a depot. In addition, the processing computer 107 is located inside the car 105 in order to store images captured by the linear sensor 103.

FIG. 17 is a flowchart showing an example of a configuration used in an adjustment method using an image capturing line adjustment element in Embodiment 3 of the present invention. As shown in FIG. 17, an adjustment method using the image capturing line adjustment element 100 in this embodiment is provided with: a “linear sensor 103” that is configured to capture an image of the image capturing line correction element 100 and whose image capturing line is adjusted by the operator 108; a "processing computer 107" that stores and displays the captured image and which the operator 108 needs to adjust the image capturing line when checking the image; and an “image capturing line adjustment element 100”, which is removable for the image capturing line in the linear sensor 103 to easily correct it. The above is a configuration of a pantograph height measuring device in this embodiment.

The calibration method for the pantograph height measuring device in this embodiment will be described below. FIG. 18 is a flowchart showing a correction method using an image capturing line adjustment element in this embodiment. Incidentally, the image capturing line adjustment element 100 to be used here is the element shown in part (a) of FIG. fifteen.

As shown in FIG. 18, in step P100, the image capturing line adjustment element 100 is attached to the pantograph 102. In this case, the center line 101 of the image capturing line correction element 100 is set to coincide with the line where the image is to be captured. Next, in step P101, the images of the image capturing line adjustment element 100 are captured by the linear sensor 103.

Then, in step P102, the line sensor 103 moves horizontally along with checking the entire captured image. In this case, the linear sensor 103 moves in such a direction that the movement causes the black parts of the image capturing line adjustment element 100 in the image to become larger so that the center line 101 of the image capturing line correction element 100 can be captured in the image, as shown in FIG. 19. Note that in each of FIG. 19-22 Io denotes the center of the image, Ia denotes the image capturing line adjustment element 100 in the image, and Ic denotes the center line 101 of the image capturing line correction element 100 in the image.

After that, in step P103, if the middle line 101 of the image capturing line adjustment element 100, which is indicated by Ic, is present at a position far from the center of the image indicated by Io, on the image capturing line adjustment element 100 in the image indicated by Ia, as shown in FIG. 19, the linear sensor 103 moves horizontally until the middle line 101 of the image capturing line adjustment element 100 indicated by Ic on the image capturing line adjustment element 100 indicated by Ia becomes closer to the center of the image indicated by using Io, as shown in FIG. twenty.

Then, in step P104, the linear sensor 103 is rotated. In this case, as shown in FIG. 21, the line sensor 103 is rotated so that the center line 101 of the image capturing line adjustment element 100 moves to a position far from the center of the image indicated by Io, inside the part corresponding to the image capturing line adjustment element 100 in the image indicated by Ia.

Then, steps P102 through P104 are repeated until, in step P105, the part corresponding to the image capturing line adjustment element 100 in the image indicated by Ia becomes completely white, as shown in FIG. 22. When the image capturing line matches the center line 101 of the image capturing line adjustment element 100, the process sequence ends. The above is a calibration method for the pantograph height measuring device in this embodiment.

Here, a principle of a method for adjusting an image capturing line in this embodiment will be described. FIG. 23 is a diagram showing an example of an image capturing line on which horizontal adjustment has not yet been performed. The image captured at this point is shown in FIG. 19. The image of the center line 101 in the image capturing line adjustment element 100 indicated by Ic 100 is captured at a position far from the center of the image indicated by Io. Note that S and Sc in FIG. 23 indicate the image capturing line in the linear sensor 103 and the center of the image capturing line in the linear sensor 103, respectively.

Next, the image capture line is adjusted in the horizontal direction. FIG. 24 is a diagram showing an example of an image capturing line on which horizontal adjustment is performed. In this case, if the center line 101 of the image capturing line adjustment element 100 indicated by Ic becomes closer to the center of the image indicated by Io, as shown in FIG. 20, this means that the center of the image capturing line in the linear sensor 103, which is indicated by Sc, is getting closer to the center line 101 of the image capturing line adjustment element 100, as indicated by M in FIG. 24. Note that S, Sc, S 'and M in FIG. 24 indicate the image capturing line in the linear sensor 103, the center of the image capturing line in the linear sensor 103, the image capturing line in the linear sensor 103 before horizontal correction and horizontal correction of the image capturing line, respectively.

If the center of the image capture line in the linear sensor 103, which is denoted by Sc, does not coincide with the continuation of the middle line 101 of the image capturing line adjustment element 100, then the image capture line in the linear sensor 103, which is denoted by S, never coincides with the middle line 101 image caption string adjusting elements 100. Since reducing the image pickup line in the linear sensor 103, which is indicated by S, to coincide with the middle line 101 of the image pickup line adjustment element 100, is the final goal, the center of the image capture line in the linear sensor 103, which is indicated by S, needs to be reduced closer to the midline 101 of the image capturing line adjustment element 100.

In other words, the center line 101 of the image capturing line adjustment element 100 in the image, which is denoted by Ic, needs to be moved closer to the center of the image, which is denoted by Io in the image. The completion of step P103 means that the center of the image capturing line in the line sensor 103 indicated by Sc is near the center line 101 of the image capturing line adjustment element 100.

Then, the image capturing line is rotationally adjusted.

FIG. 25 is a diagram showing an example of an image capturing line on which rotational adjustment is performed.

In this case, in the image, if the middle line 101 of the image capturing line adjustment element 100 in the image, which is indicated by Ic, is removed from the center of the image, which is indicated by Io in the image, as shown in FIG. 21, this means that the line sensor 103 is rotated as indicated by R in FIG. 25. Note that S, Sc, S "and R in Fig. 25 denote the image capturing line in the linear sensor 103, the center of the image capturing line in the linear sensor 103, the image capturing line in the linear sensor 103 to the horizontal adjustment and the rotational adjustment of the capturing line images respectively.

In order for the image capturing line in the linear sensor 103, which is indicated by S, to coincide with the center line 101 of the image capturing line adjustment element 100, the image capturing line in the linear sensor 103, which is indicated by S, must be parallel to the center line 101 of the correction element 100 image capture lines.

Accordingly, the image capturing line in the linear sensor 103, which is indicated by S, needs to be rotated in such a direction that rotation will make the image capturing line parallel to the center line 101 of the image capturing line adjustment element 100. To do this, the image capturing line needs to be rotated in the direction shown in FIG. 25. In particular, as shown in FIG. 21, the center line 101 of the image capturing line adjustment element 100, which is indicated by Ic, needs to be moved away from the center of the image, which is indicated by Io in the image.

The completion of step P104 means that the image pickup line in the linear sensor 103 is rotated in a direction in which the image pickup line becomes parallel to the center line 101 of the image pickup line adjustment element 100.

Note that when the linear sensor 103 is rotated in step P104, it should rotate without changing the position of the center of the image pickup line in the linear sensor 103 indicated by Sc. Therefore, it is necessary to use a tool such as stand 104, whose center of rotation does not move. By the way, any tool can be used instead of stand 104, provided that its center of rotation does not move.

FIG. 26 is a diagram showing an example of an image capturing line on which corrections are made.

By repeating steps P102 through P104, the image pickup line in the linear sensor 103, which is denoted by S, may coincide with the center line 101 of the image pickup line adjustment element 100, as shown in FIG. 26, whereby the image shown in FIG. 22. Note that S and Sc in FIG. 26 indicate an image capturing line in a linear sensor 103 and a center of an image capturing line in a linear sensor 103, respectively.

Furthermore, even when the image capturing line adjustment element 100 in the image that is indicated by Ia is on the left side of the center of the image indicated by Io, instead of the right side in the image, as shown in FIG. 19, the principle of the adjustment method will be the same.

As described above, the pantograph height measuring device and its calibration method in this embodiment make it possible to objectively determine whether the direction in which the linear sensor 103 is rotated is suitable for adjusting the slope of the image capturing line.

In addition, adjustments can be made when viewing the captured image without worrying about the actual rotation and horizontal movement of the linear sensor 103.

In addition, adjustments can be made in a simple and universal way without the need for any operator perception or experience.

In addition, as calibration accuracy is increased, the height of the pantograph 102 can be accurately measured.

INDUSTRIAL APPLICABILITY

The present invention is preferably applicable to pantograph height measuring devices and methods for calibrating them.

EXPLANATION OF REFERENCE NUMBERS

1, 3A, 3B, 3C calibration image

2 binary image

10 car

20 line sensor

30 processing computer

31 input image creating unit

32 binarization block

33 pixel width extraction unit

34 arithmetic block approximate expression

35A, 35B storage device

40 calibration element

40b black area

40w white area

50 image caption line adjustment element

50b black area

50w white area

60 monitor

S image capture line

100 Image Capture Line Correction Element

101 midline

102 pantograph

103 linear sensor

104 stand

105 wagon

106 lamp

107 processing computer

108 operator

Claims (5)

1. A pantograph height measuring device including a linear sensor and image processing means for measuring a pantograph height on a carriage that is moving, the linear sensor being placed on the roof of the car, image processing means configured to analyze an image captured by a linear sensor, characterized in that the calibration an element on which dark-colored areas and light-colored areas are arranged alternately in the vertical direction is detachably provided in a range including a range of movement a pantograph, and the image processing means is configured to obtain an expression of a relationship representing the relationship between the positions of the dark areas and light areas in the image and the actual heights of the dark areas and light areas, and calculating the actual height of the pantograph from the position of the pantograph in the image that is captured using a linear sensor using an expression of expression, wherein the positions of the dark areas and light areas are obtained from the potassium image rovochnogo element captured by the line sensor. 2. The pantograph height measuring device according to claim 1, characterized in that the image capturing line adjustment element having a plurality of first color areas combined in the vertical direction and second color areas located around the first color areas is provided detachably to the calibration element, the device measuring the height of the pantograph comprises a display means for displaying an image captured by a linear sensor, and
the shapes of the first color regions in the image capturing line adjustment element are set so that the widths of the first color regions and the second color regions shown on the display means change depending on the position and the slope of the image capturing line in the linear sensor. 3. The pantograph height measuring device according to claim 2, characterized in that in the adjustment element of the image capturing line, regions of the first color are formed having a vertical width greater in the horizontal center than on both sides of the horizontal center, so that the regions of the first color are in contact with neighboring areas of the first color in the horizontal center of the image capturing line adjustment element. 4. The pantograph height measuring device according to any one of claims 1 to 3, characterized in that the image processing means includes: an input image creating unit for creating an input image by chronological ordering of image signals input from a linear sensor; a binarization unit for creating a binary image by converting the input image to binary form; a colored area position detecting unit for detecting positions of dark areas and light areas in a binary image; and an arithmetic relationship expression unit for finding a relationship expression based on the positions of the dark color areas and light color areas in the binary image and the actual positions of the dark color areas and light color areas. 5. The pantograph height measuring device according to claim 2, characterized in that the image capturing line adjustment element includes a middle line in the horizontal center of the image capturing line correction element.

Images