JPH0283410A - Three-dimensional position measuring apparatus - Google Patents

Abstract

PURPOSE:To measure a three-dimensional position night and day without being affected by the weather or the state of a location by grasping an object to be measured by a television monitor using laser beam. CONSTITUTION:An object 9 to be measured is irradiated with laser beam having high directivity from a laser beam emitting device 2 to be caught on a television monitor 6. Next, it is judged whether the object 9 to be measured on the picture of the television monitor 6 coincides with the center of the television monitor 6, by a position deviation measuring circuit 52 and the attitude of a television camera 1 is controlled by a horizontal direction drive means 31 and a vertical direction drive means 32 to match the collimation line (l) with the object 9 to be measured. Further, the angles of rotation in horizontal and vertical directions of the camera 1 present in a reference direction are detected by encoders 41, 42 to be inputted to a coordinate calculating microcomputer 71 and the distance between the camera 1 and the object 9 to be measured is outputted to the microcomputer 71 from a distance detector 40. The microcom puter 71 calculates the position of the object 9 to be measured on the basis of the above-mentioned respective data.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a three-dimensional position measuring device that measures the position and displacement of a measurement object using a laser beam television camera.

(Prior Art) Conventionally, as a device for measuring the position of an object to be measured, a position detector using one television camera, a three-dimensional setting device using two transits, etc. are known.

The principle of a position detector using one television camera will be explained with reference to FIG.

A television camera 31 is fixedly arranged in a direction in which the measurement object 8 comes into view, and a point O above the aiming axis of the television camera 31 is set as a reference point, passing through point O and on a plane perpendicular to the aiming axis. Assume an XY orthogonal coordinate system with point O as the origin. At the same time, x
Define the y coordinate on the screen of the television monitor 32.

On the other hand, the scanning calculation means 33 generates timing pulses at regular time intervals, and when the position of the measurement object 8 captured on the screen of the television monitor 32 is specified using a light ben, a cursor, etc., the scanning calculation means 33 generates timing pulses at regular time intervals. TV monitor 3
Count the number of pulses between the measurement target 8 and the origin 0 along the scanning line of the screen of 2, and based on this number of pulses,
The coordinate position (x, y) of the measurement object 8 on the screen of No. 2 is calculated.

Then, based on this calculated value, the distance between point 0 and the television camera 31 and the distance between the point 0 and the television camera 31 are determined using the parameter setting means 35.
The position of the measuring object 8 in the virtual XY plane is calculated by multiplying the magnification factor of 1 by a preset parameter, and the result of this calculation is displayed on the television monitor 32.

Next, the principle of a three-dimensional setting device using two transits will be explained with reference to FIG.

First, 1st. The second transits 40a and 40b are fixedly set at positions separated by an arbitrary distance, and a three-dimensional image is created so that the first transit 40a is the origin O in space and the second transit 40b is on the X-Z plane. Assume a coordinate system.

Next, each horizontal angle θa, θb and each altitude angle φa, φb of the measurement object 8 are measured by human visual observation using each transit 40a, 40b. Then, the first transit 40a with respect to the second transit 40b determined in advance.
The coordinates (X, Y, Z) of the measurement target 8 are calculated by the computer 41 based on the trigonometry principle from the altitude angle φ0 of The output device 42 outputs the calculation result.

(Problem to be solved by the invention) However, each of the conventional devices described above has the following problems.

(1,) In the case of a position detector using one television camera: ■Even though the measurement object 8 does not necessarily move on the XY plane, its coordinates are detected as a projection on the XY plane. Therefore, accurate detection is impossible.

■Image taken by a television camera involves a circumference difference.

That is, as shown in FIG. 7, the image of the measurement object 8 appearing near the periphery of the screen of the television monitor 32 is distorted. Therefore, a special circuit or the like is required to correct the circumferential difference, and the correction value varies depending on the distance between the television camera 31 and the measurement object 8, etc., making accurate detection extremely difficult.

(2) Furthermore, in the case of three-dimensional measurement, the correction for the circumferential difference mentioned in (2) above becomes even more complicated.

(2) In the case of a three-dimensional setting device using two transits: Since no TV monitor is used, there is no problem with the difference in circumference. Angle θa.

θb, each altitude angle φa, φb, and each transit 4
It is difficult to identify the position in real time because it is necessary to align the aiming axes of 0a and 40b with the measurement target 8 and read the fine scale, and to input the detected data into the computer separately.

Therefore, it is difficult to accurately specify the position of the moving or deforming measurement object 8.

Therefore, the present inventors have developed a three-dimensional position measuring device that does not have measurement errors due to circumferential differences, can measure the position or displacement of a measurement target in three-dimensional coordinates in real time, and can be measured by one worker or without an operator. (Special application 1986-1)
No. 52366).

In the three-dimensional position measuring device according to this prior application, a plurality of television cameras are installed at a predetermined distance apart, the measurement target is captured on the aiming axis of these angle television cameras, and each reference aiming point of each television camera at this time is The three-dimensional position of the object to be measured is determined from the rotation angle displacement in the horizontal and vertical directions from the axis and data regarding the position of the angle television camera.

By the way, in the three-dimensional position measuring device according to this prior application, the operation of aiming each television camera at the measurement target is performed while referring to the screen of the television monitor, so it can be carried out without any problem during the daytime on clear skies, etc. We were able to solve various problems that occurred.

However, the above operation becomes difficult at night with poor visibility, in the rain, or in fog, and furthermore, when the location is complex, it becomes difficult to identify the measurement target.

Moreover, at least two television cameras are required.
There is also the problem that it is difficult to use in construction sites where space is extremely limited.

The present invention has been made in view of the above points, and its purpose is to operate regardless of the day or night, the weather such as sunny or rainy weather, or the sparseness or density of the location. Even in places where there is only space,
An object of the present invention is to provide a three-dimensional position measuring device capable of determining the three-dimensional position of a measurement object with high accuracy.

(Means for Solving the Problem) In order to solve the above object, the present inventors have provided a three-dimensional position measuring device according to the present invention, which includes a laser beam emitting device, a portion near the laser beam emitting device, A television camera that receives the laser beam emitted from the laser beam emitting device and reflected by the measurement target, a television monitor that captures the image of the television camera and displays the aiming axis of the television camera, and a television camera provided on each of the television cameras. , a television camera attitude control device capable of directing the aiming axis in any direction by rotating the television camera in the horizontal and vertical directions; and a distance corresponding to the distance from the emission of the laser beam and the reception by the television camera. rotation angle detection means for detecting signals corresponding to the horizontal and vertical rotation angles with respect to a preset reference direction of the television camera; and setting a virtual coordinate system in a three-dimensional space. and means for calculating coordinates of a measurement object existing in the three-dimensional space in the virtual coordinate system from each of the signals.

(Function) In the present invention, an origin O is defined at an arbitrary point, coordinate axis directions are specified, and various three-dimensional coordinate systems such as a spherical coordinate system and an orthogonal coordinate system are assumed in space. The coordinates of the television camera are specified in this three-dimensional coordinate system.

The laser beam emitted from the laser beam emitting device near the television camera and reflected by the object to be measured is received by the television camera while referring to the screen of the television monitor.

A signal corresponding to the distance is detected by emitting and receiving the laser beam at this time.

Next, an arbitrary reference direction of the aiming axis of the TV camera is defined, and the aiming axis is aligned with the measurement target while referring to the screen of the TV monitor by driving the TV camera attitude control device manually or automatically. .

At this time, the horizontal angle change and vertical angle change of the aiming axis from the reference direction are measured by the rotation angle detection means. The computer calculates the three-dimensional coordinates of the object to be measured from this measured value and the distance determined by the laser beam.

(Embodiment) FIG. 1 shows the layout of each part in an embodiment of a three-dimensional position measuring device (hereinafter referred to as the device of the present invention) according to the present invention.

In the figure, a television camera 1 has a laser beam emitting device 2 disposed on its top, and an attitude control device 3 disposed on its side. At the bottom of the attitude control device 3, there is a distance detection means by emitting and receiving laser light,
Rotation angle detection means (hereinafter referred to as distance/rotation angle detection means 4) are respectively installed.

A zoom device 1a is attached to the television camera 1, and a laser beam aperture device 2a is attached to the laser beam emitting device 2.

This television camera 1 includes an image processing/processing image calculation device 5
It is connected to a television monitor 6 through which images captured by the television camera 1 are captured.

Further, this image processing/processing image calculation device 5 is connected to a computer 7, and the computer 7 is equipped with an output monitor 8.

Further, the above-mentioned attitude control device 3 and distance/rotation angle detection means 4 are also connected to the computer 7, respectively.

The functions of the apparatus of the present invention in the above arrangement will be explained with reference to the block diagram of FIG.

As shown in the figure, the attitude control device 3 to which the television camera 1 is connected is composed of a horizontal drive means 31 and a vertical drive means 32. The television camera 1 can be rotated in any direction.

Further, the horizontal and vertical drive means 31 and 32 are respectively connected to devices capable of detecting rotation angles such as potentiometers and encoders of the distance/rotation angle detection means 4 shown in FIG. 1 (in this case, encoders 41 and 42). ing. Both encoders 41 and 42 serve to encode horizontal and vertical rotation angle signals output from the horizontal and vertical drive means 31 and 32, respectively.

On the other hand, the laser beam emitting device 2 and the television camera 1 are a distance detecting device 40 that detects distance by emitting and receiving a laser beam such as a light wave distance meter in the distance/rotation angle detecting means 4 shown in FIG. 1 above. This distance detection device 4
0 serves to encode the distance detection signal.

Although not shown, the laser beam emitting device 2 has built-in light source selection means for visible light, infrared light, etc., and is configured to emit appropriate light depending on the situation.

The above-mentioned image processing/processing image calculation device 5 also includes an image processing means 51 that receives image data from the television camera 1, processes the image data, and outputs processed signals to the television monitor 6; Based on the data
A positional deviation measuring circuit 52 for measuring the deviation between the J-fixed target 9 and the aiming shaft of the television camera 1, and its positional deviation measuring circuit 5
Horizontal and vertical drive means 31.3 based on the measurement signal of 2.
2, and a follow-up signal generation circuit 53 which outputs a control signal so that the aiming axis coincides with the measurement target 9.

Further, a distance detection device 40. A coordinate calculation microcomputer 71 calculates the coordinates of the measurement object 8 based on signals from encoders 41 and 42, and outputs data regarding the type of three-dimensional coordinate system and the position of the origin O of the three-dimensional coordinates to the microcomputer 71. The coordinate setting means 72 constitutes the computer 7 in FIG.

In FIG. 2, in addition to the above-mentioned elements corresponding to the respective parts in FIG. A keyboard 12 is shown as an input device.

The operation of the above embodiment will be explained below.

First, assume an arbitrary three-dimensional coordinate system in space.

In this embodiment, an XYZ orthogonal coordinate system is adopted as the three-dimensional coordinate system, the origin O of the coordinate system is set on the television camera 1, the Z axis is set in the vertical direction, and the aiming axis of the television camera 1 is set. Set the reference direction to the X-axis direction (
(See Figure 3).

Further, this XYZ coordinate system is defined on the screen of the output monitor 6 using the keyboard 12 and the coordinate setting means 72, and the television camera 1 is displayed at the origin O position.

Next, the field of view of the television camera 1 is set to a wide angle, and the television camera 1 is directed generally toward the measurement target 9 . At this time, the television camera 1 is zoomed in as necessary so that the measurement object 9 is clearly imaged on the screen of the television monitor 6.

On the other hand, the light source of the laser beam emitting device 2 is selected to be an appropriate light source such as visible light or infrared light, depending on the weather and time of the work or the situation of the location.

Note that, if necessary, the laser beam is narrowed down so that the aiming point of the measurement object 9 (to which a reflective tape or the like is attached in advance) is accurately irradiated.

Next, the operation will be explained in more detail along the flowchart of FIG.

First, in FIG. 4, a highly directional light beam such as visible light or infrared light is irradiated onto the measurement object 9 from the laser beam emitting device 2, and the measurement object 9 is captured on the television monitor 6 (step 5100). Next, the position deviation measurement circuit 52 measures the measurement target 9 on the screen of the television monitor 6 and the measurement target 9 on the screen of the television monitor 6.
(Step 5101). If the aiming axis does not match the center of the target (corresponding to the aiming line) 9, the position deviation measurement circuit 52 , and sends a follow-up signal corresponding to this positional deviation to the horizontal drive means 31 and the vertical drive means 3.
2 (step 5102).

Based on this follow-up signal, the horizontal drive means 31 and the vertical drive means 32 operate to control the attitude of the television camera 1, thereby aligning the aiming axis with the measurement object 9 (step 5103).

Next, the encoder 14 detects the deviation (horizontal and vertical rotation angles θ, φ) of the television camera 1 with respect to the reference direction. Then, coded signals corresponding to the detected rotation angles θ and φ are input to the coordinate calculation microcomputer 71 (step 5104).

On the other hand, the distance between the television camera 1 and the object to be measured 9 is detected by emitting a laser beam from the laser beam emitting device 2 and receiving the reflected light from the surface of the object to be measured 8 by the television camera 1.

This distance #! The coded signal corresponding to D is output to the coordinate calculation microcomputer 71 (step 5105).
.

The coordinate calculation microcomputer 71 determines the position (X) of the object to be measured 9 based on the above-mentioned rotation angles θ and φ and the distance between the television camera 1 and the object to be measured 9.

y, z). Then, if necessary, the position data of the measurement object 9 before movement is read out from a storage element (not shown), and the displacement amounts jx, ay, , aZ are calculated (
Step 5106).

Thereafter, the calculation results are printed out using the printer 11 or displayed on the screen of the output monitor 8 (step 5).
107).

Also, when the aiming axis coincides with the measurement target 9, steps 5102 to 5104 are skipped, and step 51 described above is skipped.
Move to 05.

The three-dimensional measurement of the measurement object 9 described above is performed repeatedly, and the measurement results are displayed on the screen of the output monitor 8 in real time.

Then, the calculation of x, y, and z in step 5107 is as follows:
For example, as is clear from Figure 3, X m D cos
φcosθ・・・・・・・・・・・・(1)
Y −D cosφs1nθ ・・・・・・・
...(2) Z = D slnφ
−(3).

Note that since the television camera attitude control device 3 is normally operated by mechanical means, it may be difficult to completely align the aiming shaft with the measurement target 9 due to the gear ratio of the gears, play, etc.

In this case, as shown by the dotted arrow in FIG. The coordinates of the measurement target are output by adding the calculated deviations.

In this way, first, the object to be measured is captured on the television monitor using laser light, and then the three-dimensional measurement operation is performed, so the measurement operation can be easily performed even in rain, fog, or at night. Furthermore, since distance is also detected using this laser light, it is easy to measure the position of the object to be measured in a three-dimensional coordinate system.

Moreover, position deviation measurement using scanning calculation can be performed by zooming up when the sighting axis is sufficiently close to the measurement target 9, so there is no longer any effect of circumferential difference, and zooming up can be done by making maximum use of the monitor screen. This allows for more accurate measurements.

In the above embodiments, the location where the television camera was installed was set as the origin of the coordinate system, but the origin position can be set completely arbitrarily.

Moreover, although the XYZ orthogonal coordinate system has been described as a three-dimensional coordinate system, this may be a cylindrical coordinate system or a spherical coordinate system, or it can also be applied to a two-dimensional coordinate system.

Furthermore, in the above embodiment, the horizontal and vertical drive means 31 and 32 for aligning the measurement target on the television monitor 6 with the aiming shaft are automatically controlled using the position deviation measurement circuit 52 and the follow-up signal generation circuit 53. Although this is done by manual operation, it can also be done manually by the operator using a remote controller or the like while visually viewing or referring to the television monitor.

(Effects of the Invention) According to the device of the present invention, the following effects can be achieved.

■Since the object to be measured is captured on a television monitor using laser light, three-dimensional position measurement can be performed without being affected by weather or location conditions, and regardless of whether it is day or night.

■Since the distance to the object to be measured is measured using a laser beam, three-dimensional position measurement can be performed using this laser beam emitting device and this television camera, making it easy to measure even in sites where space is extremely limited. can be measured.

■Te!・We decided to align the aiming axis of the TV camera with the measurement target by driving the TV camera attitude control device.
By TV cameras? Therefore, it is possible to eliminate the error caused by the circumference difference on the television monitor, which is always inevitable.

Therefore, the accurate position of the measurement target can be measured.

■Using laser light and a television camera, it is possible to immediately grasp the three-dimensional movement or deformation of the object to be measured, making real-time measurement possible.

■If a position deviation n1 constant circuit and a follow-up signal generation circuit are connected between the TV monitor and the TV camera attitude control device, the TV camera attitude control device will be driven based on the deviation between the measurement target on the TV monitor and the aiming axis. Therefore, the position measurement n1 can be performed by one worker or unmanned without requiring a plurality of workers.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the arrangement of each part in an embodiment of the device of the present invention, FIG. 2 is a functional block diagram for explaining the embodiment in FIG. 1 in detail, and FIG. 3 is an embodiment of the embodiment in FIG. 1. n in
FIG. 4 is a flowchart for explaining the operation of the embodiment shown in FIG. 1, and FIG. 5 is a diagram for explaining the principle of the conventional technique using one television camera. , FIG. 6 is a diagram for explaining the principle of the prior art using two transits, and FIG. 7 is a diagram for explaining the circumferential difference caused by a television monitor. 5... Image processing/processing image calculation device 7...
...Computer 8...Output monitor

Claims (3)

[Claims] (1) A laser beam emitting device, a television camera provided near the laser beam emitting device to receive the laser beam emitted from the laser beam emitting device and reflected by the measurement target, and capturing an image of the television camera. , a television monitor that displays the aiming axis of the television camera; and a television monitor provided on each of the television cameras;
Corresponding to the distance from a television camera attitude control device capable of directing the aiming axis in any direction by rotating the television camera in the horizontal and vertical directions, and the emission of the laser beam and the reception by the television camera. means for detecting a signal; rotation angle detection means for detecting each signal corresponding to the horizontal and vertical rotation angles with respect to a preset reference direction of the television camera; and setting a virtual coordinate system in a three-dimensional space. A three-dimensional position measuring device comprising: means for calculating coordinates of a measurement object existing in the three-dimensional space in the virtual coordinate system from each of the signals. (2) The three-dimensional position measuring device according to claim 1, further comprising a position deviation measuring circuit and a follow-up signal generating circuit connected between the television monitor and the television camera attitude control device. (3) The three-dimensional position measuring device according to claim 2, wherein the means for calculating the coordinates of the measurement object adds and outputs deviations calculated by signals from a position deviation measuring circuit. .