JPH0228510A - Method for measuring spatial position - Google Patents

Abstract

PURPOSE:To automatically measure the spatial position of a measuring point with high accuracy by detecting the positional relation between an image pickup device and the measuring point, referring to the detected positional relation and a specified interval and applying a trigonometrical survey system. CONSTITUTION:A target light source supporting member 11 provided with a target light source 10 which is the measuring point is set on a fixed jig 9 which is a substance to be measured. Light from the light source 10 is inputted in a personal computer 8 through 1st and 2nd CCD cameras 1a and 1b. After receiving the light, the computer 8 computes the spatial position of the measuring point in a measured coordinate system previously decided based on detected value, etc., from a vertical and horizontal angle detector in the case of capturing the light from the light source 10 on the center of a monitor screen by applying the trigonometrical survey system. Thus, the spatial position of the measuring point can be automatically measured with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a spatial position measuring method that can automatically measure the spatial position of a measurement point in a short time and with high accuracy.

(Prior art) - In a JR production factory, for example, on an automatic product assembly line, workpieces being assembled are transported while being held in their regular positions, and various operations are performed on these workpieces. It is supposed to be done.

An example of this is the process of attaching body side panels to the main floor of a car body assembly line in an automobile factory. The body side panel is held by this panel holding member and installed with the body side panel maintained in the correct position relative to the main floor, so that the body of the vehicle is raised. It can be assembled with precision.

Therefore, the quality of the assembly accuracy of the vehicle body is closely related to whether the spatial relationship between the plurality of fixing jigs arranged at each part on the panel holding member is maintained in a normal state. Relatedly, for this reason, it is necessary to manage the positional relationship between the plurality of fixing jigs with high precision.

In view of this need, various types of spatial position measuring devices have been put into practical use, for example, for measuring the spatial position of a measuring point by bringing a distance measuring means into contact with the measuring point.

(Problems to be Solved by the Invention) However, the above-mentioned conventional spatial position measuring device requires a step of bringing the distance measuring means into contact with the measurement point, so there is a problem that the measurement takes a long time. was there. Therefore, if you try to measure all the spatial positions of the multiple fixing jigs installed on the panel holding member mentioned above,
This will take a considerable amount of time. Furthermore, according to this technique, in order to improve measurement accuracy, it is necessary to bring the distance measuring means into contact with the measurement point with high precision, but this work is quite complicated; Conventional spatial position measuring devices have not been able to provide practically satisfactory results, and there has been a strong demand for a spatial position measuring device that eliminates the above-mentioned problems.

The present invention has been made in view of the above-mentioned circumstances,
The measurement point is imaged by switching the imaging range of the imaging means,
The purpose is to provide a spatial position measurement method that can automatically measure the spatial position of a measurement point in a short time and with high accuracy by applying a triangulation method with reference to this imaging information. shall be.

(Means for Solving the Problems) In order to achieve the above object, the present invention sets a measurement point on a base and separates two imaging means for a predetermined distance at a position where the measurement point can be imaged. after setting the imaging range of both imaging means to a wide range and imaging the measurement point, and following the imaging means to capture the measurement point at the center of the imaging range. , after switching the imaging range of the imaging means to a narrow range and imaging the measurement point, and moving the imaging means to follow so as to capture the measurement point at the center of the imaging range, the imaging means and the measurement point are A spatial position measuring method characterized in that the spatial position of the measurement point is measured by detecting the positional relationship between the points and applying a triangulation method with reference to the detected positional relationship and the predetermined interval. 6 (Function) With this configuration, the two imaging means first capture the measurement point at the center of the imaging range using wide-range input, and then the imaging range is switched to narrow-range input and the measurement point is captured at the center of the imaging range. caught in the center of At this time, the imaging means
Since the measuring point is captured at the center of the imaging range with a narrow range input, it can be said that the imaging means faces the measuring point with high accuracy. Therefore, by detecting the positional relationship between the measurement point and the imaging means at this time, applying the triangulation method by referring to the detected positional relationship, etc., and using this to measure the spatial position of the measurement point, it is possible to Spatial position can be measured automatically in a short time and with high accuracy.

(Example) Below, an example of the spatial position measuring method according to the present invention will be described in detail based on the drawings.

The present invention will be explained based on an example in which the present invention is applied to measuring the spatial position of a vehicle body fixing jig disposed on a panel holding member used in a vehicle body assembly line.

FIG. 1 is a schematic diagram of the surroundings of the spatial position measuring device, FIG. 2 is a block diagram showing the flow of signals between the devices, FIG. 3 is an operation flow chart showing the operation of the device, and FIG. 4 is a block diagram showing the flow of signals between the devices. and FIG. 5 are diagrams for explaining the present invention showing essential parts of the apparatus.

As shown in FIG. 1, a conveyor 13 that conveys a body side panel 12 as a workpiece is provided with a plurality of positioning locators 16 that allow the body side panel 12 to be moved in three dimensions with respect to the conveyor 13. On each of the positioning locators 16, a panel fixing arm 14 having a grip 18 at its tip for grasping the body side panel 12 is placed and fixed.

When the body side panel 12 is conveyed by the conveyor 13 while being gripped by the grip 18 and reaches a predetermined position, it is released from the grip 18 and a plurality of fixing jigs 9 are disposed by the conveyor 13. It is then transferred to the panel holding member 15 serving as a base. Note that this fixing jig 9 also includes the positioning locator 16 described above.
It is placed and fixed on the top of the vehicle, so that it can be positioned at a predetermined position depending on the type of vehicle body to be held. The body side panel 12 is held by the plurality of fixing jigs 9 and is attached to the floor main (not shown) while being maintained in a regular positional relationship.

Therefore, the relative positional relationship between the fixing jigs 9 disposed on the body holding member 15 is closely related to the assembly accuracy of the vehicle body. However, there is a possibility that the above-mentioned positional relationship shifts due to unpredictable reasons such as collision of workpieces. Therefore, in order to maintain the relative positional relationship between the fixing jigs 9 in a normal state, a spatial position measuring device for measuring the spatial position of the fixing jigs 9 is attached to the body holding member "15". ing.

This spatial position measuring device consists of two first and second units, as shown in FIGS. 1 and 2, and as shown in FIG. Second
A solid-state image pickup device (hereinafter referred to as
It is called a CCD element. ) as two imaging means. Image information from the second COD cameras La, lb is input to the personal computer 8 via the cable 7 and interface 19, and the image information from the first COD camera described above is input to the personal computer 8 via the cable 7 and interface 19. Second camera mounting base 2a,,
A vertical or horizontal angle adjustment motor 20a is provided on each of the mounting bases 2b and adjusts the vertical or horizontal swing angle of each mounting base 2.

20b or 21a, 21b The servo amplifiers 24a, 24b that transfer the hemotor drive command signal are connected to the interface 1.
Vertical or horizontal angle detectors 22a, 22b, or 23a are connected to the camera mounts 2a and 2b via the camera mounts 2a and 2b, respectively, and detect the vertical or horizontal swing angle of each mount 2. , 23b
are connected via an interface 19.

Further, connected to the personal computer 8 are a monitor television 25 that displays the calculation results therein, and a locator controller 26 that collectively controls the plurality of positioning locators 16.

In addition, 1. As shown in FIG. 2, the second CCD cameras la and lb have the CCD elements 30a and 30b disposed inside, and a zoom drive motor 31a,
Zoom lenses 32a and 32b configured to zoom from low magnification to high magnification are arranged by 31b,
CCD elements 30a, 30b and zoom drive motor 31a
, 31b, and transmits the input image to the microcomputer 8 and controls the zoom drive motors 31a and 31b.
33b is provided inside.

Further, the personal computer 8 has the first and second C
While referring to the image information from the CD cameras la and lb, the swing angles in the vertical and horizontal directions are calculated so that the image of the measurement point (described later) is captured at the center of the monitor screen, and this angle command is applied to the vertical and horizontal directions. In addition to feeding the angle adjustment motor, the spatial position of the measurement point is calculated based on the detected values from the vertical and horizontal angle detectors when the image of the measurement point is captured at the center of the monitor screen. It is something that performs work.

As a preparation before measuring the spatial position of the fixing jig in the spatial position measuring device configured as described above, two first... 2nd CCD camera la, l
If you prepare a set of b whose intervals are controlled with high precision, you can prepare for measurement simply by firmly fixing the plate-shaped member to the member to be measured, so the preparation procedure can be simplified. This can be simplified and is practically preferable.

After completing the above preparations, to actually measure the spatial position of the measurement point 4, as shown in FIG. A target light source support member 11 is set, and light from the target light source 10 is input to the personal computer 8 via the first and second CCD cameras la and lb. In response to this, the personal computer 8 determines the measurement coordinates determined in advance based on the detected values from the vertical and horizontal angle detectors 22 and 23 when the light from the target light source 10 is captured at the center of the monitor screen. The spatial position of the measurement point in the system is determined by calculation.

Here, to describe the target light source 10 in detail, as shown in FIG. 2 and FIG. A black spot 29 is formed on the surface of the center of the light source 28 to block the light emitted forward from the surface light source 28.
A target light source 10 is set, and the image of the surface light source 28 and the sunspot 29 is set as the first target light source 10. The spatial position of the measurement point is calculated by inputting the data to the personal computer 8 via the second COD cameras la and lb. Note that the areas of the two sunspots are sufficiently smaller than the area of the surface light source 28.

Here, the target light source is used as an example of a measurement point, but the measurement point is not limited to the above type. For example, a surface light source with an LED placed in the center may be prepared, and only the surface light source is turned on when inputting a wide range. On the other hand, the same effect can be obtained even if the surface light source is turned off and only the LED is turned on during narrow range input. In this case, the blinking of the surface light source or the LED may be switched according to a command from the personal computer.

Moreover, as another aspect, a similar effect can be obtained by providing a reflector with a non-reflective part in the center at the measurement point and irradiating this reflector with illumination.

Furthermore, as another aspect, a measurement point is provided with a color such as green instead of the reflector, and a different color such as red instead of the non-reflective part in the center,
A similar effect can also be obtained by irradiating this object with illumination and determining the color difference by image processing.

The operation of the spatial position measuring device configured in this way is explained in the third section.
This will be explained based on the operation flowchart shown in the figure. Incidentally, since the first and second CCD cameras la, 1b perform common operations until the middle of the flowchart, only the first CCD camera 1a will be explained regarding the common parts.

First, the personal computer 8 issues a drive command to the zoom drive motor 31a, and executes processing to set the zoom magnification of the zoom lens 32a to a low magnification. 1st CC
The D camera 1a performs a process of capturing an image of the surface light source 28 at a low magnification, and transfers this image information to the personal computer 8 via the interface 19 or the like (step 1).

In addition, 1. The second CCD cameras la and lb are given rough positional instructions in advance so as to take an image of the surface light source 28, so that the surface light source 28 can be immediately found.

As a result of the surface light source search in step 1, if the personal computer 8 does not detect the presence of the surface light source 28, the process returns to step 1. On the other hand, if the presence of the surface light source 28 is detected, the personal computer 8 next searches for the surface light source 28. A motor for vertical and horizontal angle adjustment in the first camera mount 2a that can capture this surface light source at the center of the imaging range based on information regarding where the light source 28 is located within the imaging range during low magnification zooming. The amount of movement of the vertical and horizontal angle adjustment motors 20a and 21a is calculated, and the calculation result is transferred to the servo amplifier 24a. While giving feedback, a tracking control process is executed so that the surface light source 28 comes to the center of the imaging range (step 3).

The personal computer 8 determines whether the surface light source 28 has come to the center of the imaging range (step 4),
As a result of the judgment in step 4, if it is not in the center, the process returns to step 3, while if it is in the center, the personal computer 6 computer 8 outputs a drive command to the zoom drive motor 31a via the interface 19 etc. Then, processing for switching and setting the zoom magnification of the zoom lens 32a to a high magnification is executed. Then, the first CCD camera 1a performs processing to image the surface light source 28 with high magnification, and transfers this image information to the personal computer 8 via the interface 19 etc. (Step 5>. At this time, the first CCD camera 1a has already 1. Because the camera mounting base 2a is roughly positioned, the surface light source 28 is located approximately at the center of the imaging range, even though the imaging range is narrowed as a high-power zoom.

After step 5 is completed, the personal computer 8 moves the black point 29 set at the center of the surface light source 28 into the imaging range based on information regarding where the black spot 29 is located within the imaging range during high-power zooming. The movement 1 of the vertical and horizontal angle adjustment motors 20a and 21a in the first camera mounting base 2a that can be captured at the center of the camera is calculated, and the calculation result is transferred to the servo amplifier 24a, and the vertical and horizontal angle adjustment motor 20a, 21a is tracked and controlled so that the black spot 29 comes to the center of the imaging range while feeding back the angle information from the vertical and horizontal angle detectors 22a and 23a (step 6).

The personal computer 8 judges whether or not the sunspot 29 has come to the center of the imaging range (step 7), and if the result of the judgment in step 7 is that it has not come to the center, the process returns to step 6; If it is determined, the process advances to step 15. Steps 1 to 7 above are the first step. Second
This is a common step between CCD cameras La and lb,
Operations similar to steps 1 to 7 are also performed in steps 8 to 14 of the second CCD camera 1b.

As a result of the determination in steps 7 and 14, if it is determined that the black spot 29 is located at the center of the imaging range, then at this time, the first . Since both the second CCD cameras la and lb capture the sunspot 29 at the center of the imaging range with narrow-range input, and therefore both face the sunspot 29 with high precision, the personal computer 8 The first one at this time. The angle detection values from the vertical angle detectors 22a, 22b and the angle detection values from the horizontal angle detectors 23a, 23b on both the second camera mounts 2a, 2b, the first. 2nd CCD camera la.

By referring to the distance between 1b and applying a well-known triangulation method, the spatial position of the sunspot 29 as a measurement point can be calculated with high precision (step 15).

Furthermore, the personal computer 8 executes processing to display this calculation result on the screen of the monitor television 25 (step 16) and outputs it to the locator controller 26, and when the series of steps 1 to 16 is completed, , the same process is executed sequentially for other fixing jigs 9 according to the order taught in advance, and when the spatial position measurement process for all the fixing jigs 9 is completed, the program is terminated.

(Effects of the Invention) As described above in detail, according to the present invention, the two imaging means first capture the measurement point at the center of the imaging range with wide area input, and then capture the measurement point in the center of the imaging range. The input is switched on and the measurement point is captured at the center of the imaging range.

At this time, since the imaging means captures the measurement point at the center of the imaging range with narrow range input, it can be said that the imaging means faces the measurement point with high accuracy. Therefore, the positional relationship between the measurement point and the imaging means at this time is detected,
By applying the triangulation method with reference to this detected positional relationship and using this to measure the spatial position of the measurement point, the spatial position of the measurement point can be measured automatically in a short time and with high accuracy. This has an extremely excellent practical effect.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram when the spatial position measuring method according to the present invention is applied to a car body assembly line, Fig. 2 is a block diagram of a spatial position measuring device using the method, and Fig. 3 is a block diagram of a spatial position measuring device using the method. , an operation flowchart showing the operation of the device; FIGS. 4 and 5 are diagrams for explaining the present invention showing essential parts of the device. la. 1b... 1st and 2nd COD camera (imaging means) 8... Personal computer, 10... Target light source (measurement point), 15... Panel holding member (base)

Claims (1)

[Claims] A measuring point is set on the base, and two imaging means are arranged so as to be movable in a two-dimensional direction with a predetermined distance apart at positions where the measurement points can be imaged, and the imaging range of both said imaging means is widened. After setting and imaging the measurement point and following the imaging means to capture the measurement point at the center of the imaging range, switching the imaging range of the imaging means to a narrow range and imaging the measurement point, After moving the imaging means so as to capture the measurement point at the center of the imaging range, detecting the positional relationship between the imaging means and the measurement point, and referring to the detected positional relationship and the predetermined interval. A spatial position measuring method, characterized in that the spatial position of the measurement point is measured by applying a triangulation method.