KR102349041B1 - An apparatus for measuring the length of an object in a non-contact manner and a method therefor - Google Patents

Abstract

The present invention relates to an apparatus for measuring the length of an object, which comprises: a camera unit for taking a picture of an object; a camera transfer unit for transferring the camera unit parallelly along a virtual line which indicates the length of the object to be measured; and a control unit for calculating the length of the object based on a distance where the camera unit is transferred. The apparatus for measuring length of an object according to the present invention transfers the camera unit such that a location of one end of the object is located at the center of the image to measures the location of the camera and then transfers the camera again parallelly to a virtual line on the surface of the object such that a location of the other end on the object is located at the center of the image to measure the location of the camera, thereby calculating the difference between the locations of the two cameras as the distance between two points on the object. During the process, a zoom lens for enlarging an image is included to obtain an enlarged image in order to locate the camera precisely at one end or the other end of the object.

Description

An apparatus for measuring the length of an object in a non-contact manner and a method therefor

The present invention relates to a technology for measuring the length of an object, and more particularly, to an apparatus and method for measuring the length of an object in a non-contact manner using a camera.

With the recent development of artificial intelligence technology, the era of unmanned crop cultivation is very near. The problem to be decided for this unmanned is the unmanned diagnosis of growth status, and for this, non-contact measurement technology is required.

Korea Patent Publication No. 2018-0121032 (published on November 07, 2018)

An object of the present invention is to provide a method and an apparatus for non-contact measurement of the length of an object using a camera.

An apparatus for measuring the length of an object in a non-contact manner according to a preferred embodiment of the present invention for achieving the above object includes a camera unit for photographing the object, and a virtual line segment indicating the length of the object to be measured. and a camera transfer unit for moving the camera unit in parallel to each other, and a control unit for calculating the length of the object according to the distance the camera unit moves.

The control unit controls the camera transfer unit to move the camera unit to a first position where one end of the object is located at the center point of the image taken from the camera unit, and to move the camera unit from the first position to the camera unit After moving the camera unit to a second position where the other end of the object is located at the center point of the image taken from It is characterized in that it is used as the length of the object.

The control unit enlarges the image by adjusting the zoom lens for magnifying the image, and the position of the karema unit so that the enlarged image of any one position of one end of the object or the other end of the object is located at the center point of the image taken from the camera unit It is characterized in that it is controlled to precisely adjust the

The camera transfer unit includes a rod-shaped transfer shaft to which the camera unit is mounted and to which the camera unit is transferred, and an angle adjusting unit for adjusting an angle between the transfer shaft and the ground surface under the control of the controller.

The control unit measures the length of the object while changing the angle formed by the direction in which the transfer shaft and the camera unit face the object through the angle adjustment unit by a predetermined angle, and changes the angle in a positive direction and a negative direction After that, the length of the object is measured while changing the measured length by a predetermined angle in the direction in which the length of the object increases. It is characterized in that it is determined by the length of the object.

In a method for measuring the length of an object in a non-contact manner according to a preferred embodiment of the present invention for achieving the above object, the camera transfer unit captures an object with respect to a virtual line segment indicating the length of the object to be measured. It includes the steps of moving the unit in parallel, and calculating, by a controller, the length of the object according to the distance the camera unit has moved.

The step of moving the camera unit in parallel includes moving the camera unit to a first position where one end of the object is located at the center point of the image taken from the camera unit, and moving the camera unit from the first position and moving the camera unit to a second position where the other end of the object is located at the center point of the image captured by the camera unit.

The present invention can be utilized for non-contact measurement of the growth state of crops. In particular, according to the present invention, it is possible to measure the height of crops, the distance between leaves, the thickness of the stem, and the growth rate over time in a non-contact manner. Based on the measurement results according to this measurement method, the growth environment can be controlled to maximize production, and labor can be reduced through automation, ultimately achieving unmanned agriculture.

1 is a block diagram for explaining the configuration of an apparatus for measuring the length of an object in a non-contact manner according to an embodiment of the present invention.
2 is a diagram illustrating a detailed representation of the configuration of an apparatus for measuring the length of an object in a non-contact manner according to an embodiment of the present invention.
3 is a view for explaining an angular change of a rotation axis of an apparatus for measuring the length of an object in a non-contact manner according to an embodiment of the present invention.
4 is a view for explaining a method of measuring the length of an object in a non-contact manner according to an embodiment of the present invention.
5 is a view for explaining a method of measuring the length of an object in a non-contact manner with respect to a distant object according to an embodiment of the present invention.
6 and 7 are diagrams for explaining a parallel measurement error according to an embodiment of the present invention.
8 is a flowchart illustrating a method for measuring the length of an object in a non-contact manner according to an embodiment of the present invention.
9 is a flowchart illustrating a method for measuring the length of an object in a non-contact manner according to an additional embodiment of the present invention.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

In describing each figure, like reference numerals have been used for like elements. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention.

The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

First, an apparatus for measuring the length of an object in a non-contact manner according to an embodiment of the present invention will be described. 1 is a block diagram for explaining the configuration of an apparatus for measuring the length of an object in a non-contact manner according to an embodiment of the present invention. 2 is a diagram illustrating a detailed representation of the configuration of an apparatus for measuring the length of an object in a non-contact manner according to an embodiment of the present invention. 3 is a view for explaining an angular change of a rotation axis of an apparatus for measuring the length of an object in a non-contact manner according to an embodiment of the present invention. 4 is a view for explaining a method of measuring the length of an object in a non-contact manner according to an embodiment of the present invention. 5 is a view for explaining a method of measuring the length of an object in a non-contact manner with respect to a distant object according to an embodiment of the present invention. 6 and 7 are diagrams for explaining a parallel measurement error according to an embodiment of the present invention.

Referring to FIG. 1 , an apparatus 10 (hereinafter, abbreviated as 'measuring device') for measuring the length of an object according to an embodiment of the present invention includes a control unit 100, a camera unit 200, and a camera transfer unit 300 ) is included.

Referring to FIG. 2 , first, the camera unit 200 is for photographing an object obj. The camera transfer unit 300 is for moving the camera unit 200 in parallel with respect to an imaginary line segment VL indicating the length of the object obj to be measured. The control unit 100 calculates the length of the object obj according to the length moved by the camera unit 200 .

The camera transfer unit 300 includes an angle adjustment unit 310 and a transfer shaft 320 . The transport shaft 320 is for transporting the camera unit 200 . This transfer shaft 320 is formed in a bar shape. The camera unit 200 is mounted on the transport shaft 320 , and the mounted camera unit 200 moves along the transport shaft 320 . Referring to FIG. 3 , the angle adjusting unit 310 is coupled to one end of the transfer shaft 320 . At this time, one end of the transfer shaft 320 is coupled to be rotated by the rotation of the rotation shaft cx of the angle adjusting unit 310 . The rotation axis CX of the angle adjusting unit 310 is perpendicular to the direction SD in which the camera unit 200 is directed toward the object and is parallel to the ground. The angle adjusting unit 310 may change the angle between the transfer shaft 320 and the direction SD toward the object by rotating the rotating shaft cx under the control of the controller 100 . Here, the direction in which the angle between the transport shaft 320 and the direction SD toward the object decreases by rotating the rotation shaft CX under the control of the transport shaft 320 and the control unit 100 is a negative direction (a). -) and the direction in which the angle increases will be referred to as a positive direction (a+). The control unit 100 measures the length of the object obj while changing the angle formed between the transfer shaft 320 and the camera unit 200 toward the object obj by a predetermined angle through the angle adjusting unit 300 . However, while changing the angle in any one of the positive direction (a+) and the negative direction (a-) to increase the length of the measured object obj by a predetermined angle, Measure the length. At this time, when the length of the object obj increases and then decreases again, the controller 100 terminates the measurement and determines the maximum value among the measured lengths as the length of the object obj.

Then, a principle of measuring the length of an object according to an embodiment of the present invention will be described with reference to FIG. 5 . When the camera unit 200 moves parallel to the surface of the object obj, that is, a virtual line segment VL indicating the length of the object to be measured, while looking at the object obj to be measured, the camera unit 200 The captured image is also moved in conjunction with the movement of the camera unit 200 . Accordingly, the actual distance on the object between the two image positions captured before and after the movement of the camera unit 200 is the same as the distance traveled by the camera unit 200 . The present invention measures the length of the object obj in a non-contact manner using this principle. To this end, the control unit 100 controls the camera transfer unit 300 to position the first end of the object at the center point F of the image photographed from the camera unit 200 or the line segment FL horizontal to the center point of the image. The camera unit 200 is moved to the position P1. Then, the control unit 100 moves the camera unit 200 from the first position P1 to the center point F of the image taken from the camera unit 200 or the object at a line segment FL horizontal to the center point of the image. The camera unit 200 is moved to the second position P2 where the other end of (obj) is located. Then, the control unit 100 calculates the distance MD that the camera unit 200 moves from the first position P1 to the second position P2, and derives the calculated distance MD as the length of the object. .

For example, referring to FIG. 4 , the control unit 200 moves the camera unit 200 up and down along the transfer shaft 320 of the camera transfer unit 300 through the camera transfer unit 300 to move the camera unit 200 to the first position P1 . move 4A shows a state in which the camera unit 200 is in the first position P1. At the first position P1, one end A of the object obj is matched with the center point F of the image taken from the camera unit 200 or the horizontal line segment FL with the center point of the image to match the camera unit 200 One end image A' of the object obj is captured at the center point F of the first image IMG1 or at a line segment FL horizontal to the center point of the image.

The control unit 200 moves the camera unit 200 downward along the transfer shaft 320 of the camera transfer unit 300 from the first position P1 to the second position P2 . That is, if the position of the object obj is fixed and the camera unit 200 is moved in a downward direction parallel to the virtual line segment VL, the center point F of the image IMG captured by the camera unit 200 Alternatively, the part in the direction of the other end (B) of the object gradually appears on the line segment (FL) horizontal to the center point of the image, and eventually, at the center point (F) of the captured image (IMG) or the line segment (FL) horizontal to the center point of the image The other end (B) of the object is matched. The position at this time is referred to as a second position P2, and (B) of FIG. 4 shows a state in which the camera unit 200 is at the second position P2. At the second position P2, the other end B of the object obj is matched with the center point F of the image taken from the camera unit 200 or the horizontal line segment FL with the center point of the image to match the camera unit 200 The other end image B' of the object obj is captured at the center point F of the second image IMG2 or the line segment FL horizontal to the center point of the image.

As a result, when the object obj is a vertical straight line and the camera unit 200 moves parallel to the straight line, the moving distance MD of the camera unit 200 and the length of the object obj coincide. Accordingly, the controller 100 may calculate the distance MD moved by the camera unit 200 as the length of the object obj.

Meanwhile, FIG. 5 is for explaining that the length of the distant object obj can be measured irrespective of the separated distance. In FIG. 5 , the first object obj1 and the second object obj2 have the same length, and the second object obj2 is located farther away from the camera unit 200 than the first object obj1 . FIG. 5(A) corresponds to FIG. 4(A), and FIG. 5(B) corresponds to FIG. 4(B). Also, the first object obj1 of FIG. 5 corresponds to the object obj of FIG. 4 .

Referring to FIGS. 5A and 5B , the center point F of the image captured by the camera unit 200 at the first position P1 or the line segment FL horizontal to the center point of the image is the first object Matching one end A of (obj1) and one end C of the second object obj2, the center point F of the image captured by the camera unit 200 at the second position P2 or the center point of the image The horizontal line segment FL matches the other end B of the first object obj1 and the other end D of the second object obj2 . That is, when the camera unit 200 is moved in parallel with the virtual line segment VL corresponding to the objects obj1 and obj2 , the moving distance MD of the camera unit 200 is the first object obj1 and the second object obj1 . It can be seen that the object obj2 travels the same distance for both. Therefore, using the method according to the embodiment of the present invention, the length of the object can be measured in a non-contact manner regardless of the distance from the camera unit 200 of the object.

However, in the case of a distant object, it appears smaller than a near object, which may cause a measurement error that may occur. As described above, according to the present invention, the length of the object can be calculated through the moving distance of the camera unit 200 . However, in order to determine a first position P1 as a starting point and a second position P2 as an end point for measuring the moving distance of the camera unit 200 , one end and the other end of the object obj to be measured are separated from the camera unit 200 . It should be checked whether it matches the center point (F) of the captured image or the horizontal line segment (FL) with the center point of the image. However, since the camera unit 200 and the image of the distant object are smaller in size than the image of the near object, and the object is expressed with a relatively small number of pixels, the position of the object cannot be accurately expressed, Matching is difficult. This is called a quantization error.

Therefore, in the present invention, the control unit 100 controls the zoom 210 of the camera unit 200 to obtain an enlarged image of the object in order to precisely adjust the position of the camera unit 200 . To this end, in the present invention, a zoom lens for magnifying an object image is installed and used to determine whether the position of one end of the object or the other end of the object coincides with the center of the image captured by the camera unit 200 . According to an embodiment of the present invention, the control unit 100 adjusts the position of the lens of the camera unit 200 through the zoom 210 of the camera unit 200 to reduce a quantization error due to digitization of an image.

6 and 7, the length of the object measured by the present invention, as shown in FIG. 6, when the object obj is not parallel to the feed shaft 320, a measurement error occurs. . In order to resolve the measurement error, the controller 100 must select the length of the object as the length measured in a state parallel to the transfer shaft 320 and the virtual line segment VL indicating the length of the object.

As shown in FIG. 6, the length MD1 of the object measured when it is not parallel to the transfer axis 320 and the virtual line segment VL indicating the length of the object and the transfer axis (MD1) as shown in FIG. 320) and an imaginary line segment (VL) indicating the length of the object and the length of the object measured when parallel (MD2) are compared, the length of the object measured when it is not parallel (MD1) is always the transfer axis 320 and It is shorter than the measured length of the object (MD2) when it is parallel to the imaginary line segment (VL) representing the length of the object. The present invention takes advantage of this point. That is, the control unit 100 measures the length by changing the direction (a-/a+) of the angle formed by the direction SD of the transfer shaft 320 and the camera unit 200 toward the object, and then the measured length is determine the direction of growth. Then, the control unit 100 changes the angle little by little in the direction in which the measurement length increases and measures. At this time, if the measured length of the object obj increases and then decreases again, the controller 100 terminates the measurement and determines the maximum value among the measured lengths as the length of the object obj. Accordingly, a measurement error with respect to the non-parallel object obj can be eliminated.

Next, a method for measuring the length of an object in a non-contact manner according to an embodiment of the present invention will be described. 8 is a flowchart illustrating a method for measuring the length of an object in a non-contact manner according to an embodiment of the present invention.

4, 5 and 8, the control unit 100 controls the camera transfer unit 300 in step S110 to the center point F of the image taken from the camera unit 200 or a line segment horizontal to the center point of the image. The camera unit 200 is moved to a first position P1 at which one end of the object is located at FL.

Then, in step S220 , the controller 100 moves the camera unit 200 from the first position P1 to the center point F of the image taken from the camera unit 200 or a horizontal line segment FL with the center point of the image. ), the camera unit 200 is moved to the second position P2 where the other end of the object obj is located.

Subsequently, the controller 100 derives the distance MD at which the camera unit 200 moves from the first position P1 to the second position P2 in step S230, and uses the derived distance MD as the length of the object. is calculated as

Next, according to an additional embodiment of the present invention, a method for measuring the length of an object 10 by solving an error in the case of non-parallelity will be described. 9 is a flowchart illustrating a method for measuring the length of an object in a non-contact manner according to an additional embodiment of the present invention.

3, 6, 7 and 9, the controller 100 determines the length of the object in the state that is the initial value of the angle between the feed shaft 320 and the direction SD toward the object in step S210. measure Here, the initial value is preferably 90 degrees. And the measurement of the length of the object is the same as the method described with reference to FIG. 8 .

Next, the controller 100 changes the angle between the transfer shaft 320 and the direction SD toward the object in step S220 to a predetermined angle to each of a positive direction (a+) and a negative direction (a-). , measure the length of the object (obj). Then, the controller 100 determines the angle change direction in the direction in which the length measured in step S230 increases.

Then, in step S240, the control unit 100 changes the angle between the transfer shaft 320 and the direction SD toward the object in the previously determined direction (S230) by a predetermined angle. Whenever the angle is changed, the controller 100 measures the length of the object obj according to the method described in FIG. 8 in step S250 and records the measured length of the object obj.

Then, in step S260 , the controller 100 determines whether the length of the currently measured object has increased compared to the previously measured length of the object. As a result of the determination in step S260, if the length of the object is increased, steps S240 to S260 are repeated.

On the other hand, if it is determined in step S260 that the measured length of the object is reduced, the controller 100 determines the maximum value of the lengths of the object measured so far in step S270 as the length of the object.

Meanwhile, the method according to the embodiment of the present invention described above may be implemented in the form of a program readable by various computer means and recorded in a computer readable recording medium. Here, the recording medium may include a program command, a data file, a data structure, etc. alone or in combination. The program instructions recorded on the recording medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software. For example, the recording medium includes magnetic media such as hard disks, floppy disks and magnetic tapes, optical recording media such as CD-ROMs and DVDs, and magneto-optical media such as floppy disks ( magneto-optical media), and hardware devices specially configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions may include high-level languages that can be executed by a computer using an interpreter or the like as well as machine language such as generated by a compiler. Such hardware devices may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

Although the present invention has been described above using several preferred embodiments, these examples are illustrative and not restrictive. As such, those of ordinary skill in the art to which the present invention pertains will understand that various changes and modifications can be made in accordance with the doctrine of equivalents without departing from the spirit of the present invention and the scope of rights set forth in the appended claims.

10: measuring device
100: control unit
200: camera unit
210: zoom
300: camera transfer unit
310: angle adjustment unit
320: feed axis

Claims (8)

An apparatus for measuring the length of an object in a non-contact manner, comprising:
a camera unit for photographing an object;
a camera transfer unit for moving the camera unit in parallel with respect to an imaginary line segment indicating the length of an object to be measured; and
Including; and a control unit for calculating the length of the object according to the distance moved by the camera unit;
The camera transfer unit may include: a rod-shaped transfer shaft to which the camera unit is mounted and the camera unit is transferred; and an angle adjusting unit that adjusts the angle between the transfer shaft and the ground surface according to the control command of the controller.
The control unit, through the angle adjusting unit, measuring the length of the object while changing the angle formed by the transfer shaft and the direction in which the camera unit directs the object by a predetermined angle,
After changing the angle in the positive direction and the negative direction, the length of the object is repeatedly measured while changing by a predetermined angle in the direction in which the measured length of the object increases,
When the length of the object increases and then decreases again, the measurement is terminated, and a maximum value among the measured lengths is determined as the length of the object.
A device for measuring the length of an object. According to claim 1,
the control unit
By controlling the camera transfer unit
Moving the camera unit to a first position where one end of the object is located at the center point of the image taken from the camera unit,
After moving the camera unit from the first position to a second position where the other end of the object is located at the center point of the image taken from the camera unit, the camera unit is moved,
calculating the distance the camera unit moves from the first position to the second position,
characterized in that the calculated distance is used as the length of the object
A device for measuring the length of an object. According to claim 1,
the camera unit
and a zoom lens for magnifying an object image in order to determine whether the position of one end of the object or the other end of the object coincides with the center of the image captured by the camera unit
A device for measuring the length of an object. 4. The method of claim 3,
the control unit
The image is enlarged by adjusting the zoom lens for magnifying the image of the object, and the position of the camera unit is precisely adjusted so that the enlarged image of any one position of one end of the object or the other end of the object is located at the center point of the camera image. characterized by
A device for measuring the length of an object. delete delete A method for measuring the length of an object in a non-contact manner, the method comprising:
moving the camera unit for imaging an object in parallel with respect to an imaginary line segment indicating the length of the object to be measured by the camera transfer unit;
Calculating, by the control unit, the length of the object according to the distance moved by the camera unit;
The camera transfer unit may include: a rod-shaped transfer shaft to which the camera unit is mounted and the camera unit is transferred; and an angle adjusting unit that adjusts the angle between the transfer shaft and the ground surface according to the control command of the controller.
In the step of moving the camera unit in parallel and calculating the length of the object,
The control unit, through the angle adjusting unit, measuring the length of the object while changing the angle formed by the transfer shaft and the direction in which the camera unit directs the object by a predetermined angle,
After changing the angle in the positive direction and the negative direction, the length of the object is repeatedly measured while changing by a predetermined angle in the direction in which the measured length of the object increases,
When the length of the object increases and then decreases again, the measurement is terminated, and a maximum value among the measured lengths is determined as the length of the object.
A method for measuring the length of an object. 8. The method of claim 7,
The step of moving the camera unit in parallel
moving the camera unit to a first position where one end of the object is located at a center point of the image taken from the camera unit; and
moving the camera unit from the first position to a second position where the other end of the object is located at a center point of the image captured by the camera unit;
characterized in that it comprises
A method for measuring the length of an object.

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