JP6625030B2 - Three-dimensional measurement system and three-dimensional measurement method - Google Patents

Description

  The present invention relates to a three-dimensional measurement system and a three-dimensional measurement method for consistently managing processes from surveying, design, construction planning, and inspection.

  In March 2016, the Ministry of Land, Infrastructure, Transport and Tourism introduced “i-Construction,” which fully manages surveying, design, construction planning, and inspection by using ICT technology at construction sites in full, especially using three-dimensional data. Hammered out. With this, it is expected that the value of three-dimensional data will further increase in the construction industry as a whole, and furthermore, the value of three-dimensional measuring devices and three-dimensional measuring methods will also increase.

  For example, in Patent Document 1, as a three-dimensional image measurement method, a CAD figure shape of a measurement target is expressed as a set of points on a translocation of a measurement target, and a three-dimensional parallel / rotational movement amount is directly given to obtain a captured image. A technique has been disclosed in which, when collating with CAD data, a CAD figure is subjected to various coordinate transformations so that the CAD drawing data can accurately simulate the photographing process of a camera.

  In such a three-dimensional measurement system, there are mainly two measurement methods. The first method is to install the machine body at a known point and observe a target located at one or more known points. The second method is to install the machine body at an arbitrary location and observe targets located at two or more known points.

JP-A-10-89960

  However, when the conventional observation method is used, an error (misalignment) occurs in combining data of a plurality of measurements. This error can range from a few mm to a few cm. In obtaining a point cloud for a structure, it is necessary to create a result in which this error has a very small value.

  Therefore, an object of the present invention is to provide a three-dimensional measurement system and a three-dimensional measurement method that can reduce an error to an extremely small value.

  In order to achieve the above object, a three-dimensional measurement system according to the present invention includes a three-dimensional laser scanner and a target placed on at least two known coordinate points observed by the three-dimensional laser scanner, A target installed on a leveling table having a bubble tube and a cylindrical bubble tube.

  Further, the three-dimensional measurement method of the present invention is a three-dimensional measurement method using the three-dimensional measurement system, such that a distance between the three-dimensional laser scanner and the two targets is 10 m or more and 120 m or less, And setting the target such that an internal angle between the three-dimensional laser scanner and the two targets is not less than 30 degrees and not more than 150 degrees.

  As described above, the three-dimensional measurement system of the present invention includes a three-dimensional laser scanner, a target placed on at least two known coordinate points observed by the three-dimensional laser scanner, and a circular bubble tube and a cylinder. And a target placed on a leveling table having a tubular bubble. With such a configuration, when combining the acquired point group data, it is possible to reduce the coordinate error of the target and eliminate the poor connection.

  Further, the three-dimensional measurement method of the present invention is a three-dimensional measurement method using the three-dimensional measurement system, such that a distance between the three-dimensional laser scanner and the two targets is 10 m or more and 120 m or less, And setting the target such that an internal angle between the three-dimensional laser scanner and the two targets is not less than 30 degrees and not more than 150 degrees. With such a configuration, when combining the acquired point group data, it is possible to reduce the coordinate error of the target and eliminate the poor connection.

It is a perspective view explaining the composition of the whole three-dimensional measurement system. It is a top view of a leveling stand. It is explanatory drawing explaining the range of the distance and angle of a three-dimensional measuring method. It is explanatory drawing explaining the procedure in the case of measuring a road. It is an arrangement | positioning figure (square arrangement) of the apparatus at the time of measuring a square-shaped structure. It is an arrangement | positioning figure (diagonal arrangement | positioning) of the apparatus at the time of measuring a square-shaped structure. It is an arrangement | positioning figure of the apparatus at the time of measuring one side of a square structure. FIG. 4 is a layout diagram of devices in an experiment. It is the whole point cloud data of an experiment result. It is point cloud data of a pier of an experiment result. It is a list of the error in a measurement result.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Constitution)
First, the overall configuration of the three-dimensional measurement system 1 of the present invention will be described with reference to FIG. As shown in FIG. 1, a three-dimensional measurement system 1 according to the present invention includes a three-dimensional laser scanner 2 and two targets 3 and 3. As will be described later, in the three-dimensional measurement system 1 and the three-dimensional measurement method of the present invention, a point cloud is acquired by scanning (scanning) the structure 90 with the two targets 3 and 3 by the three-dimensional laser scanner 2. The shape and position of the structure 90 are specified from the acquired point cloud.

  The three-dimensional laser scanner 2 is a device that measures the position and shape of an object by scanning the object (object to be measured) with a laser beam, and is either a time-of-flight method or a phase difference method. Is also good. Hereinafter, the case of the time-of-flight method will be described as an example. In the case of the time-of-flight method, (1) laser light is emitted, (2) reflection on the object (no reflector is required), (3) return time is measured and converted into a distance, (4) photograph The measurement work is performed in the order of photographing (when the current color is added to the point cloud). In the case of a time-of-flight system, data of 50,000 points per second can be obtained in a range of 360 degrees × 270 degrees.

  In this way, a TIN mesh is created based on the three-dimensional point cloud data acquired by the three-dimensional laser scanner 2, and a two-dimensional CAD drawing can be created. Further, by combining the plan drawing and the current point cloud data, it can be used as modeling data. A cross section can be cut out.

  As will be described later, the coordinates of the position where the three-dimensional laser scanner 2 is installed are calculated backward by scanning the targets 3 and at least two known points simultaneously with the scanning of the object by the three-dimensional laser scanner 2. Based on the obtained coordinates of the three-dimensional laser scanner 2, the coordinates of the point cloud data obtained by scanning are obtained.

  The target 3 is a white circle drawn in the center of a blue circular plate. By scanning the figure with the three-dimensional laser scanner 2, the target 3 is recognized. Since the target 3 needs to be accurately set on a known coordinate point, the target 3 is set on a leveling table 4 attached to a tripod 5.

  That is, the target 3 of the present invention is set on a leveling table 4 that can be set more accurately on a known coordinate point than a conventional tripod. The leveling table 4 has a circular bubble tube 41 and a cylindrical bubble tube 42, thereby increasing the installation accuracy on coordinate points. That is, the target 3 is installed on the leveling table 4 in order to prevent a human error occurring when the target 3 is installed. In the conventional method of setting the target 3 (as indicated by the manufacturer), the level of the target 3 is determined by one circular bubble tube. In the present invention, the leveling table 4 is set on the tripod 5, and the target 3 is set on the leveling table 4. By using the circular bubble tube 41 and the cylindrical bubble tube 42 mounted on the leveling table 4, the horizontal error and the vertical axis error of the target 3 can be reduced. If this method is used, it is possible to reduce the coordinate error of the target 3 at the time of combining the acquired point group data and eliminate the poor connection.

  Hereinafter, a method for reducing an observation error when measuring a structure will be described with reference to FIGS. 3 to 6. In the present invention, the positional relationship is adjusted so that two or more targets 3, 3 can be observed in one measurement. That is, in the three-dimensional measurement method of the present invention, the distance between the three-dimensional laser scanner 2 and the two targets 3 and 3 is set to be 10 m or more and 120 m or less, and the three-dimensional laser scanner 2 and the two targets 3 and 3 are set. The targets 3 and 3 are set so that the inner angle formed by the angle θ is not less than 30 degrees and not more than 150 degrees. However, the following contents can be measured by relaxing the numerical value depending on the measurement site. Hereinafter, the arrangement will be specifically described.

The positional relationship between the three-dimensional laser scanner 2 (hereinafter, referred to as “body body 2”) (FIG. 3: white circle) and the targets 3, 3 (FIG. 3: black square) is a positional relationship that satisfies the following equation (1). Be careful.
10m <L <120m (1)

At the site where the structure is measured, attention is paid so that the internal angle (α) between the machine body 2 and the two targets 3 and 3 has a positional relationship satisfying the following expression (2).
30 degrees <α <150 degrees (2)

At a site where a structure requiring higher accuracy is measured, when the vertex of the body 2 is O and the vertices of the two targets 3 and 3 are A and B, the angle between the inner angle (β) and OA and OB It should be noted that the positional relationship of satisfies the following expression.
β = 60 degrees and OA = OB ... (3)

  Next, the positional relationship between the structure 90, the targets 3, 3 and the body 2 will be described while paying attention to the above equations (1) to (3).

(Method of measuring roads)
First, a case of measuring a road using the three-dimensional measuring method of the present invention will be described with reference to FIG.
[1] With the expressions (1) to (3) described above in mind, the main body 2 (FIG. 3: white circle) and the targets 3 and 3 (FIG. 3: black square) are installed and the first time. Perform measurement.
[2] In the second measurement, the airframe main body 2 is installed on one target 3 used in the first measurement, and a new one is taken in consideration of the equations (2) and (3) described above. A good target 3.
[3]... [2] are repeated. At this time, the measurement is proceeded while confirming that the road can be measured uniformly.

(Measurement method for square structures (square arrangement))
Next, a case of measuring a quadrangular structure (a structure having a substantially quadrangular planar shape) using the three-dimensional measurement method of the present invention will be described with reference to FIG. The three-dimensional measuring method for measuring a quadrangular structure according to the present invention includes the steps of: drawing a square in contact with all the vertices of the quadrangular structure; installing the three-dimensional laser scanner 2 at any of the vertices of the square; Setting the two targets 3 and 3 so that the distances between the two targets 3 and 3 are substantially the same from the three-dimensional laser scanner 2 installed in the three-dimensional laser scanner 2; Scanning the square structure together with the steps 3 and 3. Hereinafter, the arrangement will be specifically described.
[1] Draw a square all in contact with the vertices of the structure (FIG. 5: square indicated by solid line and broken line in the center). The fuselage body 2 (FIG. 5: white circle) is set at the top of this square.
[2] The targets 3 and 3 are installed on the opposite side of the range where the structure is viewed from the installation location of the body 2 (FIG. 5: black square). At this time, line segments connecting the body 2 installed at the apex and the two targets 3, 3 are set to be equidistant. The angle extending from the body 2 to two line segments is the same at all four points.
[3] The distance from the adjacent installation point of the body 2 to the targets 3 is set to be an isosceles triangle.

(Measurement method for square structures (diagonal arrangement))
With reference to FIG. 6, a case where a rectangular structure is measured using the three-dimensional measurement method of the present invention will be described. The three-dimensional measuring method for measuring a quadrangular structure according to the present invention includes the steps of installing the three-dimensional laser scanners 2 and 2 on one diagonal line of the quadrangular structure, and setting the targets 3 and 3 on the other diagonal line of the quadrangular structure. And setting the targets 3 and 3 so that the interior angle between the three-dimensional laser scanner 2 and the two targets 3 and 3 is 90 degrees. Scanning the rectangular structure with the targets 3,3. Hereinafter, the arrangement will be specifically described.
[1] ... The fuselage body 2 (Fig. 6: white circle) and the target (Fig. 6: black) extend on the diagonal vertices of the structure (Fig. 6: square indicated by the solid line and broken line in the center). Square).
[2] At this time, the angle between the body 2 and the two targets 3 is set to 90 degrees.

(Measurement method for square structures (single-sided measurement))
With reference to FIG. 7, a case where a rectangular structure is measured using the three-dimensional measuring method of the present invention will be described. The three-dimensional measurement method for measuring a rectangular structure according to the present invention uses the three-dimensional laser scanner 2 at any symmetric position on both sides of the normal, with the normal extending from the center of one side of the square structure as the axis of symmetry. Setting, setting the two targets 3, 3 at symmetrical positions on both sides of the normal with the normal as the axis of symmetry, and the three-dimensional laser scanner 2 and the quadrangular structure together with the two targets 3, 3 Scanning. Then, the same measurement is performed from the back side, and the point group data of the observation from the front side and the observation from the back side are combined to complete the measurement of the rectangular structure. Hereinafter, the arrangement will be specifically described.
[1] A perpendicular line (normal line) is drawn from one side surface of the structure (FIG. 7: a square indicated by a solid line and a broken line in the center). An arbitrary point is provided on the perpendicular, and a line parallel to one side surface passing on the arbitrary point is provided.
[2] The body 2 is installed at a position extending equidistantly on a parallel line from an arbitrary point (FIG. 7: white circle).
[3]... The targets 3 and 3 (FIG. 7: black squares) are installed at positions visible from the body 2. At this time, the positional relationship between the targets 3 and 3 is an isosceles triangle having an arbitrary point on the parallel line as a vertex.

(effect)
Next, the effects of the three-dimensional measurement system 1 and the three-dimensional measurement method according to the present embodiment will be listed and described.

(1) As described above, the three-dimensional measurement system 1 of the present invention includes a three-dimensional laser scanner 2 and a target 3 placed on at least two known coordinate points observed by the three-dimensional laser scanner 2, 3 and targets 3 and 3 installed on a leveling table 4 having a circular bubble tube 41 and a cylindrical bubble tube 42. According to such a configuration, when combining the acquired point group data, it is possible to reduce the coordinate error of the targets 3 and 3 and eliminate the poor connection.

(2) The three-dimensional measurement method of the present invention is a three-dimensional measurement method using the three-dimensional measurement system 1, wherein the distance between the three-dimensional laser scanner 2 and the two targets 3, 3 is 10 m or more and 120 m or less. And setting the targets 3 and 3 so that the interior angle between the three-dimensional laser scanner 2 and the two targets 3 and 3 is not less than 30 degrees and not more than 150 degrees. More preferably, the internal angle (β) is set to 60 degrees, and the distances from the three-dimensional laser scanner 2 to the targets 3 are preferably equal. With such an arrangement, errors can be reduced.

(3) The three-dimensional measuring method for measuring a quadrilateral structure includes a step of drawing a square in contact with all the vertices of the quadrilateral structure and installing the three-dimensional laser scanner 2 at any of the vertices of the square. Setting two targets 3 and 3 from the three-dimensional laser scanner 2 installed at the apex so that the distance between the two targets 3 and 3 is substantially the same; Scanning a rectangular structure with the three targets 3,3. Therefore, by suppressing the number of targets 3 to be installed and accurately measuring each side surface of the rectangular structure one by one from the front, it is also possible to eliminate poor connection of the entire data.

(4) The three-dimensional measuring method for measuring a quadrangular structure includes a step of setting the three-dimensional laser scanner 2 on a diagonal line of the quadrangular structure and a step of setting the targets 3 and 3 on a diagonal line of the quadrangular structure. And setting the targets 3 and 3 so that the interior angle between the three-dimensional laser scanner 2 and the two targets 3 and 90 is 90 degrees. Scanning the quadrilateral structure together with. .. And the number of replacements of the three-dimensional laser scanner 2 can be minimized, and the quadrangular structure can be accurately measured to eliminate the connection failure of the entire data.

(5) A three-dimensional measuring method for measuring a quadrilateral structure is a three-dimensional laser scanner located at a symmetric position on either side of the normal with a normal extending from the center of one side of the quadrilateral as a symmetry axis. 2; setting the two targets 3, 3 at symmetrical positions on both sides of the normal with the normal as the axis of symmetry; and the three-dimensional laser scanner 2 forms a quadrangle with the two targets 3, 3. Scanning the structure. For this reason, by measuring one side of the quadrilateral structure twice from the front direction from the installation positions of the two three-dimensional laser scanners 2, the measurement accuracy of particularly important side is improved, and the connection failure of the entire data is improved. Can be eliminated.

  Hereinafter, a verification experiment of the three-dimensional measurement system 1 and the three-dimensional measurement method proposed in the present invention will be described with reference to FIGS. The same or equivalent parts as those described in the above embodiment will be described with the same reference numerals.

  The purpose of this demonstration experiment is to compare and verify the measurement accuracy of the target 3 using the leveling table 4 with the measurement accuracy of the standard target, and to evaluate the measurement accuracy based on the angle and positional relationship between the target 3 and the body 2 of the aircraft. It is to verify. To verify the measurement accuracy, the coupling error of the two measurements was compared. In the field, the measurement was performed on one side surface (measurement target surface) of the pier in a positional relationship between the body 2 and the target 3 as shown in FIG. The positional relationship between the target 3 and the body 2 is as shown in FIG.

In the verification experiment, measurement was performed for the following cases (1) to (4).
(1) The targets 3 and 3 using the leveling table 4 are set on TG1 and TG2, and the measurement is performed with the body 2 set on K1.
(2) The targets 3 and 3 using the leveling table 4 are set on TG1 and TG2, and the measurement is performed with the body 2 set on K2.
(3) The standard targets are set on TG1 and TG2, and the body 2 is fixed on K3 for measurement.
(4) Standard targets are set on TG1 and TG2, and the body 2 is set on K4 for measurement.
On the day after the measurement, accurate latitude, longitude and height of TG1 and TG2 were observed using a total station.

  9 and 10 show point cloud data of the experimental results. 9 and 10, the point cloud data is output in monochrome, but actually, the point cloud data can be output in color according to the reflection intensity.

  The total measurement error and the measurement error in three directions in each measurement are summarized in a table shown in FIG. The use of the leveling table 4 allowed the measurement error to be within 1 mm. On the other hand, when a standard target was used, the measurement error was 4 mm. In this measurement, the distance between the body 2 and the object to be measured and the distance between the body 2 and the target were in the range of 10 m ≦ L <20 m. However, it is considered that the value of the measurement error increases as the distance increases. In the measurement of a structure, an error of several centimeters greatly affects subsequent steps. High accuracy using the measurement method of the present invention is considered to be very useful.

  The other configuration and operation and effect are substantially the same as those in the first embodiment, and thus description thereof is omitted.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention may be applied to the present invention. included.

Reference Signs List 1 3D measurement system 2 3D laser scanner 3 Target 4 Leveling table 5 Tripod 41 Circular bubble tube 42 Cylindrical bubble tube 90 Structure

Claims (3)

A three-dimensional laser scanner, and a target installed on at least two known coordinate points observed by the three-dimensional laser scanner, the target being installed on a leveling table having a circular bubble tube and a cylindrical bubble tube. A three-dimensional measurement method for measuring a square structure using a three-dimensional measurement system, comprising:
The distance between the three-dimensional laser scanner and the two targets is 10 m or more and 120 m or less, and the interior angle between the three-dimensional laser scanner and the two targets is 30 degrees or more and 150 degrees or less. Setting the target , further comprising:
Drawing a square in contact with all the vertices of the quadrangular structure, and installing the three-dimensional laser scanner at any of the vertices of the square;
From the three-dimensional laser scanner installed at any of the vertices, installing two targets so that the distance between the two targets is substantially the same,
Scanning the rectangular structure with the two targets using the three-dimensional laser scanner. A three-dimensional laser scanner, and a target installed on at least two known coordinate points observed by the three-dimensional laser scanner, the target being installed on a leveling table having a circular bubble tube and a cylindrical bubble tube. A three-dimensional measurement method for measuring a square structure using a three-dimensional measurement system, comprising:
The distance between the three-dimensional laser scanner and the two targets is 10 m or more and 120 m or less, and the interior angle between the three-dimensional laser scanner and the two targets is 30 degrees or more and 150 degrees or less. Setting the target , further comprising:
Installing the three-dimensional laser scanner on a diagonal line of the rectangular structure,
Installing the target on a diagonal line of the quadrangular structure, wherein the three-dimensional laser scanner and the target make an internal angle of 90 degrees, the step of installing the target,
Scanning the rectangular structure with the two targets using the three-dimensional laser scanner. A three-dimensional laser scanner, and a target installed on at least two known coordinate points observed by the three-dimensional laser scanner, the target being installed on a leveling table having a circular bubble tube and a cylindrical bubble tube. A three-dimensional measurement method for measuring a square structure using a three-dimensional measurement system, comprising:
The distance between the three-dimensional laser scanner and the two targets is 10 m or more and 120 m or less, and the interior angle between the three-dimensional laser scanner and the two targets is 30 degrees or more and 150 degrees or less. Setting the target , further comprising:
A step of installing the three-dimensional laser scanner at any position symmetrical on both sides of the normal line, with a normal line extending from the center of one side surface of the square structure as a symmetry axis,
Setting the two targets at symmetrical positions on both sides of the normal with the normal as a symmetry axis;
Scanning the rectangular structure with the two targets using the three-dimensional laser scanner.