JPH10170622A - Automatic follow-up method and automatic follow-up device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively and automatically follow up a position at moving time of a moving body with high accuracy by adding a light emitting body to the moving body, and detecting a moving position of the moving body on the basis of an image difference between images of the light emitting body before and after the moving body is moved. SOLUTION: Three targets 3 to 5 composed of a reflecting target seal are added to a moving body 1, and a doughnut-shaped light emitting body 6 composed of a light emitting diode 6 is arranged around the respective targets 3 to 5. In a condition where a surveying equipment 2 is stopped, images of the light emitting body 6 before and after the moving body 1 is moved are taken in, and an operation is performed on a difference between both images, and moving speed of a surveying head 8 of the surveying equipment 2 is adjusted. The surveying head 8 is moved (oscillated) at preset speed, and is controlled so that a position of the light emitting body 6 always comes to a central part of an image of a CCD camera 7, and images before and after the light emitting body 6 is moved are picked up, and a moving position of the light emitting body 6 (the moving body 1) is found from an image difference between the respective images. Therefore, a position at moving time of the moving body 1 can be always standardized, and a device can easily and automatically follow up the moving body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tracking method and an automatic tracking device for locating the position of a moving object by imaging a target attached to the moving object.

[0002]

2. Description of the Related Art Conventionally, as a system for tracking the position of a moving body, a manual type in which an operator collimates a target attached to the moving body is most generally used. However, in such a manual type system, there is a problem that a burden on an operator is large and it is difficult to track with high accuracy. Therefore,
In order to solve such problems, various automatic tracking type surveying systems have been proposed and put into practical use. As a conventionally known automatic tracking type surveying system, there is a system using a laser beam and a reflector. This system has a prism on the moving body side,
A reflector such as a cat's eye, a corner cube, etc. is installed. A laser beam is projected from the surveying instrument side to this reflector, and the reflected beam is detected by a photodiode or the like. The head of the surveying instrument is controlled to swing so as to hit the center of the surveying instrument.

[0003]

However, among the above-mentioned automatic tracking type surveying systems, those using a prism have a problem that the accuracy is not as good, and those using a cat's eye and a corner cube are expensive. There is a problem that it has to be.

An object of the present invention is to provide an automatic tracking method and an automatic tracking apparatus capable of automatically following a moving position of a moving body at a low cost and with high accuracy in order to solve such problems. Is to provide.

[0005]

In order to achieve the above-mentioned object, an automatic tracking method according to the present invention is directed to a method in which a target which is attached to a moving body and comprises a reflector and a luminous body is used. An auto-following method for locating the position of the moving body by capturing an image with an imaging unit and performing image processing, wherein a difference image of each image of the light-emitting body before and after the movement of the moving body is captured by the imaging unit. The moving position of the moving body is obtained based on the following.

In the present invention, the target attached to the moving body is constituted by a reflector such as a reflection seal and a light emitting body such as a light emitting diode (LED), and the moving position of the moving body is obtained. Next, images before and after the movement of the light-emitting body are taken by an image pickup means such as a CCD camera, and the movement position is obtained by image processing based on a difference image between these taken images. In this way, the position of the moving body during the movement can be always located, and the following of the moving body can be automated by a simple method.

In the present invention, when the target cannot be imaged by the imaging means, a coordinate connecting jig having at least three targets is installed at a required position, and coordinate connecting is performed using the coordinate connecting jig. Is preferred. In this way, when the moving body is too far away from the imaging unit, or when the target cannot be measured due to the orientation of the moving body, and the imaging unit is moved,
Before and after the movement, a coordinate connection can be performed to capture an image.

Next, an automatic tracking device according to the present invention for specifically realizing the automatic tracking method includes the steps of: (a) capturing an image of a target which is attached to a moving body and is composed of a reflector and a luminous body; And (b) image processing means for calculating a moving position of the moving body based on a difference image of each image of the light-emitting body before and after the moving body is imaged by the imaging means. Is what you do.

In the present invention, it is preferable that the apparatus further comprises control means for controlling the imaging means so as to move the position of the light emitting body after the movement of the moving body to the center of the imaging means. In this case, the control unit increases the moving speed of the imaging unit as the position of the illuminator after the movement is closer to the end of the imaging unit or as the amount of movement of the illuminator before and after the movement increases. It is preferable to control the imaging means as described above. By doing so, it is possible to reliably prevent the moving body from coming off the imaging means (screen), and to accurately follow the moving body.

The image processing means may binarize a difference image between the images of the luminous body before and after the movement of the moving body, and calculate a center of gravity of a portion extracted by the binarization processing. The moving position of the moving body may be calculated by calculating the position before and after the movement of the light emitting body from the calculation result.

In the present invention, it is preferable that a coordinate connecting jig having at least three targets for connecting the coordinates is provided at a required position when the target cannot be imaged by the image pickup means.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, specific embodiments of the automatic tracking method and the automatic tracking device according to the present invention will be described with reference to the drawings.

FIG. 1 shows a system configuration of an automatic tracking system according to an embodiment of the present invention. The automatic tracking system according to the present embodiment includes a moving object 1 as an object to be measured, a surveying device 2 for locating the position of the moving object 1, and an image processing device for processing an image captured by the surveying device 2. And a controller (both not shown) for controlling the swinging of a survey head 8 described later based on a command from the image processing apparatus.

As shown in FIG. 2, a three-point target (a first target 3, a second target 4, and a third target 5) composed of three reflective target seals is attached to the moving body 1, as shown in FIG. I have. Each target 3, 4,
5 has a target sticker made of a point symmetrical figure affixed to the center thereof, and by measuring these three targets 3, 4, and 5 with the surveying instrument 2, the coordinates of the moving body 1 and the coordinates The position can be located.

A donut-shaped light-emitting body 6 composed of a light-emitting diode group is provided around the first target 3, and by capturing an image of the light-emitting body 6, the position of the moving body 1 will be described later. Can be followed.

The surveying instrument 2 includes a surveying head 8 having a CCD camera 7 as an image pickup means for photographing an image of the light emitting body 6, and the surveying head 8 is mounted on the moving body 1
A head drive mechanism (not shown) for swinging in the horizontal and vertical directions in accordance with the moving direction of the camera. As described above, the image captured by the CCD camera 7 is processed by the image processing device attached to the surveying instrument 2, and the head driving mechanism is controlled by the controller based on the processing result. . Note that the image processing apparatus is provided with a monitor screen 9 (see FIG. 4) as a display means for displaying an image captured by the CCD camera 7.

Next, a control operation of the surveying instrument 2 for following the moving body 1 will be described with reference to a flowchart shown in FIG.

S1: Initially, if the processed image is a negative (<0) image, the image processing board of the image processing apparatus is set to zero (0). S2-S
3: While the surveying instrument 2 is stopped, a current image of the moving body 1, that is, an image before the moving body 1 is moved (image 1) is captured. Next, an image of the moving object 1 after m seconds (0.3 seconds in this embodiment) with the surveying instrument 2 still stopped,
In other words, the image (image 2) after the movement of the moving body 1 is captured.

S4 to S5: The image 1 is subtracted from the image 2 to obtain the image 3, and the image 2 is subtracted from the image 1 to obtain the image 4. As described above, by calculating the difference image between the image including the light emitting body 6 before and after the movement of the moving body 1, the background that does not move becomes zero (0) regardless of the brightness, so that the image after the movement (image 2 ), The image 3 before moving is subtracted from the image (image 1) to obtain an image 3 in which only the bright spot after moving is obtained. On the other hand, when the image after moving (image 2) is subtracted from the image before moving (image 1) An image 4 in which only bright points before the movement remain is obtained.

S6 to S7: The images 3 and 4 obtained in this way are binarized, respectively, and the center of gravity (centroid) of the portion extracted by the binarization, that is, the center of gravity of the light-emitting body 6 after the movement and before the movement And the center of gravity of the luminous body 6 are determined. S8: To adjust the speed of the survey head 8 of the surveying instrument 2 based on the center of gravity of the image 3 and the center of gravity of the image 4 obtained in the previous step, the horizontal speed a1 and the vertical speed b1 of the survey head 8 are determined. Obtained by calculation. The details of this speed adjustment will be described later with reference to the flowchart shown in FIG.

S9-S10: The survey head 8 is swung for n seconds (2 seconds in this embodiment) based on the set speed, and thereafter, the command speeds in the horizontal direction and the vertical direction are set to 0, thereby turning the head. Stop the swing operation.

By such a series of processes, as shown in FIG. 4, the image before the movement of the luminous body 6 captured by the CCD camera 7 is moved from the center to the edge of the CCD camera 7 by the movement of the moving body 1. When the measurement head 8 is deviated to the side, the control is performed so that the survey head 8 is swung and the light emitter 6 is returned to the center of the CCD camera 7. The orientation of the coordinate system of the moving body 1 is performed by measuring the three targets 3, 4, and 5 with the surveying head 8 of the surveying instrument 2.

Next, step S in the above-mentioned flowchart will be described.
A process flow for adjusting the speed of the survey head 8 in FIG. 8 will be described with reference to a flow chart shown in FIG. 5 while referring to an area instruction diagram shown in FIG.

S801-S822: The center of gravity (i, j) of the image (image 3) of the light-emitting body 6 after the movement is located in which area of the screen shown in FIG. 6, in other words, on the end side. The horizontal speed a1 and the vertical speed b1 of the survey head 8 are set as follows depending on whether the survey head 8 is located at the center or the center. (1) When the barycentric coordinates (i, j) are in the A region a1 = V1, b1 = V2 (2) When the barycentric coordinates (i, j) are in the B region a1 = V3, b1 = V4 (3) The barycenter A1 = V5, b1 = V6 when coordinates (i, j) are in region C (4) a1 = V7, b1 = V8 when coordinates (i, j) are in region D (5) barycentric coordinates (i, j) When j) is in the E region a1 = V9, b1 = V10 (6) When the barycentric coordinates (i, j) are in the F region a1 = V11, b1 = V12 (7) When the barycentric coordinates (i, j) are G A1 = V13, b1 = V14 (8) When the barycentric coordinates (i, j) are in the H region a1 = V15, b1 = V16 (9) When the barycentric coordinates (i, j) are in the I region a1 = V17, b1 = V18 (10) When the barycentric coordinates (i, j) are in the J area a1 = V19, b 1 = V20 (11) When the barycentric coordinates (i, j) are in the K region a1 = V21, b1 = V22 Here, the horizontal direction speed a1 is determined by the barycentric coordinates (i, j) being the end region (regions A and C). , D, H, I, K), the moving speed is set to be higher.
1 indicates that the barycentric coordinates (i, j) are in the end regions (regions A, B, C,
(I, J, K), the moving speed is set to increase.

S823 to S826: The amount of movement L of the barycentric coordinates (i, j) of the image of the light emitter 6 before and after the movement is the first.
Is less than the set value K1, the horizontal speed a′1 of the survey head 8 is set to V23, and the vertical speed b′1 is set to V24. When the movement amount L is smaller than a second set value K2 which is larger than the first set value K1, the horizontal speed a'1 of the survey head 8 is set to V2.
5, and the vertical speed b'1 is set to V26. Here, these V23 to V26 are set to be larger as the movement amount L is larger.

S827: The larger one of the horizontal velocities a1 and a'1 set in the above-described steps is used as the final horizontal velocities a1 and the vertical velocities b1 and b'1 The larger one of these speeds is defined as the final vertical speed b1.

By such a series of processing, the light emitting body 6
As the position after the movement of the light-emitting body 6 is closer to the end of the screen, or as the movement amount L before and after the movement of the light-emitting body 6 is larger, the survey head 8
Is controlled so that the moving speed of the
It is possible to reliably prevent the light-emitting body 6 from coming off the screen of the camera 7, so that the moving body 1 can be accurately followed.

By the way, when following the moving body 1 by using the surveying instrument 2 as described above, the light emitting body 6 is moved due to the moving body 1 being too far from the surveying instrument 2 or the orientation of the moving body 1. If the survey cannot be performed, the surveying instrument 2 itself is moved as shown in FIG. In this case, since it is necessary to perform coordinate connection before and after the movement of the surveying instrument 2, a coordinate connection jig 11 having at least three (six in this embodiment) targets 10 is installed at a required position.
Each target 10 of the coordinate connecting jig 11 is
It is preferable to connect the coordinates by measuring before and after the movement.

In the above description, each target 3, 4, 5
, For example, the direction of a vector from the target 3 to the target 4 does not always change.
However, when it is considered that the direction of the vector changes due to the movement of the moving body 1, a sensor (for example, a gyro) capable of detecting the moving direction is mounted on the moving body 1, The amount of change in the vector may be detected by the sensor.

Further, the control of the surveying instrument can be performed by remote control using a wireless communication.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of an automatic tracking system.

FIG. 2 is a diagram illustrating a three-point target;

FIG. 3 is a flowchart illustrating a processing flow for following a moving object;

FIG. 4 is an explanatory diagram of an automatic following operation.

FIG. 5 is a flowchart illustrating a processing flow for adjusting the speed of the survey head.

FIG. 6 is a diagram illustrating an area of an image captured by a CCD;

FIG. 7 is a diagram for explaining a method of connecting coordinates.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Moving body 2 Surveying instrument 3 First target 4 Second target 5 Third target 6 Light emitting body 7 CCD camera 8 Surveying head 10 Target 11 Coordinate connecting jig

 ──────────────────────────────────────────────────の Continuing on the front page (72) Motohide Yasukawa 8-2-12 Nanko-Higashi, Suminoe-ku, Osaka-shi Inside Ogis Soken Co., Ltd. (72) Takayuki Kataoka 3-1-1 Ueno, Hirakata-shi, Osaka (72) Inventor Daiki Morimoto 3-1-1 Ueno, Hirakata-shi, Osaka Komatsu Manufacturing Co., Ltd.

Claims (7)

[Claims] 1. An automatic tracking method for locating a position of a moving body by imaging a target attached to the moving body and configured by a reflector and a luminous body by an imager and performing image processing on the target. An automatic tracking method, wherein a moving position of the moving body is obtained based on a difference image of each image of the light emitting body before and after the moving body is moved by the imaging unit. 2. A coordinate connecting jig having at least three targets at a required position when the target cannot be imaged by the image pickup means, and coordinate connecting is performed using the coordinate connecting jig. Automatic follow-up method described in 1. 3. An image pickup means for picking up an image of a target which is attached to a moving body and is composed of a reflector and a luminous body, and b. An automatic tracking device comprising: an image processing unit that calculates a moving position of the moving body based on a difference image between the images of the light emitting body. 4. A control means for controlling the image pickup means so as to move the position of the light emitting body after the movement of the movable body to a central portion of the image pickup means.
6. The automatic tracking device according to claim 1. 5. The image processing means binarizes a difference image between the images of the illuminant before and after the movement of the moving body, and calculates a center of gravity of a portion extracted by the binarization processing. The automatic tracking device according to claim 3, wherein the movement position of the moving body is calculated by calculating a position before and after the movement of the light emitting body from the calculation result. 6. The moving speed of the image pickup means increases as the position of the light emitter after the movement is closer to the end of the image pickup means or as the amount of movement of the light emitter before and after the movement increases. 6. The automatic tracking device according to claim 4, wherein the image pickup means is controlled so as to increase the size. 7. A coordinate connecting jig having at least three targets for connecting a coordinate at a required position when said target cannot be imaged by said image pickup means. An automatic tracking device according to any one of the claims.