JPH04352206A - Automatic tracking device for measurement point - Google Patents

Abstract

PURPOSE:To provide the automatic tracking device which automatically track the displaced measurement point even if the measurement point is greatly displaced at the time of measurement point measurement using a CCD camera. CONSTITUTION:The automatic tracking device is equipped with an image analysis part 33 which analyzes the photodetection position 5a of reflected light on the image pickup plane 6a of the CCD camera 6, a range setting part 36 which sets the range of the photodetection position 5a on the image pickup plane 6a so that the range can freely be varied, and a comparison part 31 which compares the photodetection position 5a on the image pickup plane 6a with the displacement limit range 6c set by a range setting part 36. When the photodetection position 5a is positioned outside the displacement limit range 6c, the driving of a main body driving means is so controlled according to the comparison result of the comparison part 31 so that the photodetection position is inside the displacement limit range 6c.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic measuring point tracking device for automatically monitoring the behavior of slopes associated with landslides, cutting or embankment construction.

0002

[Prior Art] Conventionally, in order to monitor the displacement of structures and the behavior of excavated slopes, a device for measuring ground displacement has been proposed, for example, in Japanese Patent Application No. 59-140276, in which a theodolite and a light wave distance meter are automatically driven. Automatic displacement measurement that recognizes the measurement point by detecting the amount of reflected light from the reflective prism, measures the high angle, horizontal angle, and distance, calculates the three-dimensional coordinates of the measurement point pedestal, and controls the drive of theodolite, etc. An apparatus is disclosed.

[0003] In addition, a laser beam is irradiated onto a reflective prism installed at a measuring point, and the reflected light is received by a CCD camera for image analysis, and calculations are performed using separately measured oblique distance data to determine the tertiary dimension of the measuring point. A method and apparatus for obtaining original coordinates have also been proposed.

0004

However, when measuring a measuring point using the CCD camera, if the displacement of the measuring point exceeds the imaging range of the CCD camera,
The drawback was that it became completely impossible to measure.

[0005] The present invention has been made to solve the above-mentioned problems, and its purpose is to detect the displaced measuring point even if the measuring point is significantly displaced when observing the measuring point using a CCD camera. An object of the present invention is to provide an automatic tracking device for automatically tracking measurement points.

[0006]

[Means for Solving the Problems] The present invention has been made in view of the above objects, and the gist thereof is to provide a laser beam irradiation means for irradiating a laser beam toward a measurement point, and a laser beam irradiation means installed at the measurement point. a CCD camera that receives reflected light from the reflecting means;
body driving means for horizontally and vertically driving a device body including the laser beam irradiation means and the CCD camera;
an image analysis means for analyzing the light receiving position of the reflected light on the imaging surface of the D camera; a range setting section for changingably setting the range of the light receiving position of the reflected light on the imaging surface; a comparison means for comparing the light reception position of the reflected light on the imaging surface and the displacement limit range set by the range setting section; and a drive control means for controlling the drive of the main body drive means so that the light receiving position is located inside the displacement limit range when the light receiving position is located within the displacement limit range.

[0007]

[Operation] A displacement limit range that defines the range of displacement of the measurement point is set in advance on the imaging surface of the CCD camera by the range setting section, and the receiving position of the reflected light is set within the displacement limit range on the imaging surface. When the light is received beyond the threshold, the main body of the device is driven. In the measurement, the main body drive means is controlled by the drive control means to perform initial settings so that the reflected light from the measuring point is located approximately at the center of the displacement limit range. Next, measurements are performed at regular time intervals or continuously, and the image analysis means analyzes the reception position of the reflected light observed by the CCD camera, and
The light receiving position of the reflected light on the imaging surface of the CD camera and the displacement limit range are compared by a comparing means. As a result,
If the receiving position of the reflected light is located inside the displacement limit range, the apparatus main body does not change its position and continues measurement at that position. Furthermore, if the receiving position of the reflected light is observed to be outside the displacement limit range, the reflected light from the displaced measuring point is again within the displacement limit range based on the comparison result of the comparison means. The drive control means drives and controls the main body drive means so that it is located approximately at the center.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An automatic measuring point tracking device according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an automatic tracking device, which is composed of a measuring section 1 that measures the displacement of a measuring point, and an arithmetic control section 20 that performs arithmetic processing on the measurement results of the measuring section 1.

The measurement unit 1 includes a laser oscillator 5 as a laser beam irradiation means for irradiating a laser beam onto a reflecting prism 14 installed at a measuring point, and a CCD camera 6 for capturing the reflected light of the laser beam from the reflecting prism 14. , multifocal lens 7
and a refraction device section 8. Each of the measuring instruments is integrally fixed to a fixed frame 9, and the fixed frame 9 is connected to a support plate 10.
It is pivoted on top. A rack is provided at the lower end of the fixed frame 9, and a pulse motor (
(not shown), and functions as a vertical drive device 13. The support plate 10 is the rotary table 1
1, and the rotary table 11 is rotated in the horizontal direction by a horizontal drive device 12 (see FIG. 1).

FIG. 2(a) shows a block diagram of the internal circuit of the arithmetic control section 20. For convenience of explanation, the automatic tracking circuit 30 is shown in FIG.
Only relevant parts are shown. In FIG. 2A, the automatic tracking circuit 30 includes an image analysis unit 33 that analyzes the light receiving position of the reflected light received by the CCD camera 6, and a range setting unit that sets the range of the light receiving position 5a of the reflected light on the imaging surface. section 36, a comparison section 31 that compares the receiving position of the reflected light on the imaging surface analyzed by the image analysis section 33 and the displacement limit range set by the range setting section 36, a laser oscillator 5, a CCD camera 6, etc. It is composed of a control section 32 as a control means for driving and controlling the fixed device main body in the horizontal and vertical directions.

FIG. 2(b) shows the imaging surface 6a of the CCD camera 6.
shows. The CCD camera 6 has a large number of pixels 6b, which are gate electrodes, arranged vertically and horizontally on a silicon substrate (350 pixels x 420 pixels), and by operating an input key 35, the approximate center of the imaging surface 6a is shaped into a frame. The pixels 6b are selected so as to surround them, and the inner range is set as the range where the light receiving position 5a of the reflected light from the reflection prism 14 forms an image on the imaging surface 6a, that is, the displacement limit range 6c. The set displacement limit range 6c is registered in the range setting section 36.

The comparison section 31 compares the positional relationship between the light receiving position 5a on the imaging surface 6a analyzed by the image analysis section 33 and the displacement limit range 6c set in the range setting section 36. As a result of the comparison, the light receiving position 5a is as shown in FIG. 2(c),
As shown in (d), when the device is located inside the displacement limit range 6c, the drive control of the device main body is not performed, and as shown in FIG.
As shown in (e), the control unit 32 controls the drive of the horizontal movement device 12 and the vertical movement device 13 only when the light receiving position 5a is located outside the displacement limit range 6c.

In response to the comparison result from the comparison section 31, the control section 32 controls the main body of the apparatus so that the light receiving position 5a is located at the reference position of the centroid of the imaging surface 6a shown in FIG. 2(c). Drive. The amount of movement controlled by the control unit 32 is determined by the number of pixels in the horizontal and vertical directions existing between the reference position and the reflected light receiving position shown in FIG. 2(e), and the set multifocal point. It is determined from the focal length f of the lens 7. As an example, when the focal length is 1200mm, one pixel is 3.2
This corresponds to 4 seconds. Further, at this time, in the control unit 32, it is also possible to operate the input key 35' to set the tracking accuracy, that is, the accuracy tolerance value of the tracking movement amount. In this case, if the tracking accuracy is set to zero, the amount of tracking movement will be equal to the amount of movement of the measurement point.

Further, FIG. 3 shows the relationship between the displacement amount of the measuring point and the displacement limit range. Focusing on the measurement point with the largest amount of displacement among the plurality of measurement points, the displacement limit range can be read from the expected amount of displacement. If this amount of displacement exceeds a certain value (approximately 25 pixels for a CCD camera), it becomes impossible to measure distance using a light wave distance meter, so it is necessary to set the displacement limit range to 25 pixels or less. For example, if the expected displacement of a measurement point at a distance of 500 m is 10 cm, the displacement limit range is approximately 1
There are 4 pixels.

A measurement procedure using the automatic measuring point tracking device configured as described above will be explained.

First, by manual operation using the input key 35', the horizontal/vertical drive device 12,
13 is driven to collimate the reflective prism 14 in which the laser oscillator 5, CCD camera 6, etc. are installed at the measurement point. Further, the displacement limit range 6c, tracking accuracy, etc. are input using the input keys 35, 35'.

Next, the laser beam emitted by the laser oscillator 5 is irradiated in the direction of the measuring point through the refracting device 8 from the same optical axis as the optical axis of the multifocal lens 7. The irradiated laser light is
The reflected light is accurately reflected by the reflecting prism 14 installed at the measurement point, passes through the multifocal lens 7 again, and forms an image on the CCD camera 6. The image data detected by the CCD camera 6 is analyzed by the image analysis section 33, and the light receiving position 5a of the reflected light on the imaging surface 6a is detected.

Next, in the comparison section 31, the range setting section 3
The positional relationship between the displacement limit range 6c set at 6 and the light receiving position 5a of the reflected light detected by the image analysis unit 33 is compared. As a result, when the light receiving position 5a is located inside the displacement limit range 6c, the drive control of the device main body is not performed, so tracking is not performed.

Further, when the light receiving position 5a is located outside the displacement limit range 6c (see FIG. 2(e)), drive control of the horizontal movement device 12 and the vertical movement device 13 is performed. The control unit 32 calculates the number of pixels between the reference position of the centroid of the imaging surface 6a and the reflected light receiving position 5a, and calculates the number of pixels in the horizontal and vertical directions based on the set focal length of the multifocal lens 7. The main body of the device is rotated to perform automatic tracking (FIG. 2(f)). After a certain amount of time has passed,
By performing the above tracking operation again, automatic tracking of the measurement point becomes possible.

[0021] Furthermore, the automatic tracking device shown in this embodiment is
By using it in combination with "Method and device for automatic measuring point displacement measurement" (Japanese Unexamined Patent Publication No. 3-31715) previously proposed by the present applicant, a single displacement measuring device can automatically measure a large number of measuring points. It is also possible to automatically track the object while observing the object.

A displacement measuring device that automatically performs tracking will be described below. First, the measurement position/range setting section 36'
The control unit 32 drives the horizontal and vertical drive devices 12 and 13 based on the measurement position data (horizontal angle and vertical angle data) of each measurement point stored in Aim at 6. Next, a laser oscillator 5 irradiates a laser beam toward a reflecting prism 14 installed at a measuring point, and a CCD camera 6 receives the reflected light. The image data detected by the CCD camera 6 is analyzed by the image analysis section 33, and the light receiving position 5a of the reflected light on the imaging surface 6a is detected.

Next, the calculation/comparison section 31' compares the positional relationship between the displacement limit range 6c set in the measurement position/range setting section 36' and the light receiving position 5a of the reflected light detected by the image analysis section 33. . As a result, when the light receiving position 5a is located outside the displacement limit range 6c, the drive control of the horizontal movement device 12 and the vertical movement device 13 is performed. The control unit 32 calculates the number of pixels between the reference position of the centroid of the imaging surface 6a and the reflected light receiving position 5a, and calculates the number of pixels in the horizontal and vertical directions based on the set focal length of the multifocal lens 7. Rotate the main body of the device to perform automatic tracking (Figure 2 (
c) to (f)).

As a result of this automatic tracking, new measurement position data (horizontal angle and vertical angle data) of the moved measurement point is stored in the measurement position/range setting section 36'. On the other hand, the calculation/comparison unit 31' calculates the angle data of the measurement point obtained from the light receiving position data of the reflected light and the moved new measurement position data, and the oblique distance data of the measurement point obtained from the light wave range finder 4. is calculated to obtain the three-dimensional coordinates of the displaced measurement point. After the measurement at one measurement point is completed, another measurement position data is output from the measurement position storage section 34, and the above-mentioned measurement is repeated to measure all the set measurement points.

[0025]

[Effect] According to the automatic measuring point tracking device according to the present invention, the range setting section sets the range of the light receiving position of the reflected light on the imaging surface, and the comparison means sets the range of the light receiving position of the reflected light on the imaging surface and the range of the light receiving position of the reflected light on the imaging surface. The displacement limit range set in the range setting section is compared, and based on the comparison result, if the light receiving position of the reflected light is located outside the displacement limit range, the light receiving position is located inside the displacement limit range. Since the drive control means controls the drive of the main body drive means so that the measurement point is located, the measurement point can be automatically tracked very quickly and accurately using image processing technology using a CCD camera. It becomes possible. Furthermore, by setting the displacement limit range in the range setting section small, it becomes possible to accurately follow even rapid and large displacement amounts.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing an automatic tracking device according to the present invention.

FIG. 2(a) is a block diagram showing the configuration of an automatic tracking device according to the present invention, FIG. 2(b) is a schematic plan view showing an imaging surface of a CCD camera, and FIGS. 2(c) to ( e) is an explanatory diagram showing the positional relationship between the position where the reflected light is received on the imaging surface and the displacement limit range, and FIG. FIG.

FIG. 3 is a graph showing the relationship between the displacement amount of a measuring point and the number of pixels set in the displacement limit range, using focal length as a parameter.

FIG. 4 is a block diagram showing another embodiment.

[Explanation of symbols]

5 Laser oscillator (laser beam irradiation means) 5a Light receiving position 6 CCD camera 6a Imaging surface 6c Displacement limit range 12 Horizontal direction drive device (main body drive means) 13 Vertical direction drive device (main body drive means) 14 Reflection prism (reflection prism) 31 Comparison section (comparison means) 32 Control section (drive control means) 33 Image analysis section 36 Range setting section

Claims (1)

[Claims] a laser beam irradiation means for irradiating a laser beam toward the measurement point;
C that receives the reflected light from the reflecting means installed at the measurement point.
a CD camera, a main body drive means for horizontally and vertically driving a device main body including the laser beam irradiation means and a CCD camera, and an image analysis means for analyzing a receiving position of the reflected light on an imaging surface of the CCD camera. , a range setting section for changeably setting the range of the light receiving position of the reflected light on the imaging surface, and a displacement limit range set by the light receiving position of the reflected light on the imaging surface analyzed by the image analysis means and the range setting section. and a comparison means for comparing the light receiving position with the light receiving position of the reflected light is located inside the displacement limit range when the light receiving position of the reflected light is located outside the displacement limit range based on the comparison result of the comparison means. and a drive control means for controlling the drive of the main body drive means.