JPH04296605A - Position detection device - Google Patents

Abstract

PURPOSE:To carry out accurate position detection even when a detected body is vertically slipped from a standard horizontal level by correcting a detected value of a camera system by way of detecting the height of the detected body from the standard horizontal level with a contact sensor. CONSTITUTION:A contact sensor 27 to detect height of a first drain hole 16 from a horizontal standard level 26 is provided, and its height measurement Z is detected with it. Actual measurement (l) of the first drain hole 16 in the horizontal direction is processed under l=(l+ Z/Z)Xl1 by a processing unit of a camera system 20. But Z is to be height measurement from the standard level 26 to a first one point camera 21. Consequently, it is possible to carry out accurate position detection in the horizontal direction even when a car body is slipped vertically from the standard level 26.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detection device used for detecting the set position of a vehicle body on a production line, for example, in an automobile manufacturing process.

0002

[Background Art] For example, in an automobile manufacturing process, when an industrial robot screws bolts or applies sealant to a car body on the line, it is necessary to ensure that each of these tasks can be performed accurately. Therefore, prior to these operations, it is first necessary to accurately detect the position of the vehicle body at that time. Conventionally, a camera system has been used as a device for this detection, and some of these are configured as follows. That is, this camera system includes a camera that is disposed above or below a detected portion that is set on a part of a vehicle body that is a detected object. Then, the same camera system detects the horizontal position of the detected portion recognized by the camera, and outputs the detection signal to the industrial robot. Then, this industrial robot performs a predetermined work on the vehicle body at the position determined by the detection signal.

0003

[Problems to be Solved by the Invention] By the way, since the camera with the above-mentioned conventional configuration recognizes the detected part from above or below, there may be problems such as improper setting of the detected part on the line. If the detected portion deviates vertically from a certain horizontal reference plane, the camera will produce an error in position detection in the horizontal direction in accordance with the vertical deviation. Therefore, the position of the vehicle body determined based on the detection signal from the camera system includes an error, which causes the inconvenience that the subsequent work by the industrial robot cannot be performed accurately.

0004

[Purpose of the Invention] This invention was made in view of the above-mentioned circumstances, and it is possible to accurately detect the position of the detected object even if the detected object is shifted vertically from a horizontal reference plane. An object of the present invention is to provide a position detection device that allows the user to perform the following tasks.

[0005]

[Means for Solving the Problems] A feature of the present invention for achieving the above object is that the camera system is a camera disposed obliquely above a detected part set as a part of a detected object. In the position detection device, the camera system detects the horizontal position of the detected part recognized by the camera and outputs a detection signal, wherein the detected part is detected from a horizontal reference plane. A contact sensor for detecting the height of the part is provided, and a detection signal output from the camera system is corrected using a detection signal of the height from the contact sensor.

[0006]

[Operation] The operation of the above configuration is as follows. In FIG. 1, a first one-point camera (camera) 21 recognizes a first water drain hole (detected part) 16 set in a part of a vehicle body (detected object) 1 from diagonally above. There is. In this case, the first one-point camera (camera) 21 is connected to the first drain hole (
The above recognition is performed on the premise that the detected part) 16 is set on a certain horizontal reference plane 26 on the line. For this reason, the setting of the vehicle body (object to be detected) 1 on the line may be incorrect, and the first drain hole (detected part) 16 may be moved from the horizontal reference plane 26 to the solid line in Figure 1 above. If the position has shifted to the point shown in , the first drain hole (detected part) 16 is actually at the position shown by the solid line in the figure, which means that the first one-point camera (camera ) 21, but according to the recognition only by the first one-point camera (camera) 21, the first drain hole (
The detected part) 16 is a first one-point camera (camera) 21 on a horizontal reference plane 26, as shown by reference numeral 16a in the figure.
It is determined that the first drain hole (detected portion) 16 is located at a distance of a dimension l from the position 16, and this determination includes an error of Δl in the horizontal position of the first drain hole (detected portion) 16.

Therefore, in order to eliminate such inconveniences, the present invention provides a contact sensor 2 for detecting the height of the first drain hole (detected portion) 16 from the horizontal reference plane 26.
There are 7. The contact sensor 27 detects the first water drain hole (detected portion) 1 from the horizontal reference surface 26.
If the height dimension ΔZ of 6 is detected, the actual dimension l in the horizontal direction is calculated by the following formula. l=(l+ΔZ/Z)×l1 However, the dimension Z is the height dimension from the horizontal reference plane 26 to the first one-point camera (camera) 21. Therefore, even if the vehicle body (object to be detected) 1 is vertically displaced from the horizontal reference plane 26, the position of the vehicle body (object to be detected) 1 in the horizontal direction can be accurately detected.

[0008]

Embodiments Hereinafter, embodiments of the present invention will be explained with reference to the drawings. (First Embodiment) FIGS. 1 to 4 show a first embodiment. In FIGS. 2 and 3, reference numeral 1 denotes a vehicle body, which is an object to be detected, set on a production line in an automobile manufacturing process. For convenience of explanation, the direction indicated by arrow Fr in FIG. 2 is defined as the front, and left and right refer to directions toward the front.

The vehicle body 1 includes a floor panel 2 that is rectangular in plan view, and rocker arms 3 that are attached to the left and right ends of the floor panel 2, respectively. A tunnel 4 is formed in the left and right center portions of the floor panel 2, and an exhaust pipe 5 is to be accommodated in the tunnel 4 in a later process. Furthermore, a heat insulator 6 for blocking heat from the exhaust pipe 5 is attached to the lower surface of the tunnel 4, and this heat insulator 6 is attached to the floor panel 2 with bolts 7. The vehicle body 1 is set on the above line by placing the rocker arms 3, 3 on the hooks 10 of the overhead hanger 9 on the above line. As the overhead hanger 9 moves forward, various works are performed on the vehicle body 1.

In FIG. 3, reference numeral 11 denotes a tool, and this tool 11 is attached to the end of an arm 12a of the industrial robot 12 shown in FIG. 4, and is movable horizontally and vertically below the vehicle body 1. This tool 11 includes a screw rotating part 13 and a camera 14, and when the vehicle body 1 reaches a predetermined position, the arm 12a engages the screw rotating part 13 with the bolt 7 according to a detection signal from the camera 14, and Let it be concluded.

2 and 3, first to fourth drainage holes 16 to 19 are formed in the floor panel 2 for draining water during electrodeposition coating, and these holes are formed in a part of the vehicle body 1. This is the detected part that is set. Reference numeral 20 denotes a camera system, and this camera system 20 is connected to the first drain hole 1.
6 and a first one-point camera 21 and a second one-point camera 22 arranged above when viewed from the third drain hole 18. Moreover, as shown in FIG.
and a calculation unit 24 that outputs a detection signal based on a digital signal of position data in the horizontal direction (x, y direction) of the third drain hole 18.

In FIGS. 1 to 4, the first drain hole 16 and the third drain hole 18 from a certain virtual horizontal reference plane 26
A contact sensor 27 is provided to detect the height of each. This contact sensor 27 has a pneumatic cylinder 28 with a vertical axis, and this pneumatic cylinder 28 has a cylinder tube 29 attached to the tool 11 and a piston rod 30 that projects upward from the upper end of this cylinder tube 29. have. Further, the detecting section body 31 of the contact sensor 27 has a vertical axis, and has a pipe-shaped casing 32 attached to the piston rod 30 and a contact bar 33 protruding from the upper end of the casing 32 so as to be able to rise and fall freely. This contact bar 33 is urged upward by a spring, and a Magnescale is provided within the casing 32 corresponding to this contact bar 33.

1 and 3 so that the contact sensor 27 does not interfere with the work when using the tool 11.
As shown by the solid line, the pneumatic cylinder 28 is contracted so that its upper end is located below the screw rotating part 13. Next, the contact sensor 27 detects the first water drain hole 16 and the third water drain hole 18 from the horizontal reference surface 26.
When detecting the height dimension ΔZ, as shown in FIG.
into position. Next, as shown by the dashed line in FIG. The contact bar 33 is brought into pressure contact. Then, the height dimension ΔZ is detected based on the vertical relative change of the contact bar 33 with respect to the casing 32 at this time.

In FIG. 4, as described above, the contact sensor 27 outputs data in the vertical direction (Z direction) as an analog signal, which is input to the arithmetic unit 24 via the A/D converter 35. Further, the output signal of the arithmetic unit 24 is inputted to the industrial robot 12 and other robots 37 and 38 via a robot control panel 36.

By the way, in FIG. 1, the first one-point camera 21 is designed to recognize the first drain hole 16 set in a part of the vehicle body 1 from above. In this case, the first one-point camera 21 assumes that the first drain hole 16 is set on a certain horizontal reference plane 26 on the line as shown by the two-dot chain line in the figure. It is supposed to be recognized. For this reason, if the first drain hole 16 deviates from the horizontal reference plane 26 to the point shown by the solid line in Figure 1 above due to improper setting of the vehicle body 1 on the line, etc. In reality, the first drain hole 16 is located at the position shown by the solid line in the figure, that is, it is located at a distance of a distance l from the first one-point camera 21 in the horizontal direction. According to the recognition of only the first one-point camera 21, the first drain hole 16 is located at a distance of a dimension l from the first one-point camera 21 on the horizontal reference plane 26, as shown by the reference numeral 16a in the figure. This judgment includes an error of Δl in the horizontal position of the first drain hole 16.

In order to solve this problem, the present invention provides a contact sensor 27 for detecting the height of the first drain hole 16 from the horizontal reference surface 26. Then, when the contact sensor 27 detects the height dimension ΔZ of the first drain hole 16 from the horizontal reference plane 26, the actual horizontal dimension l can be determined by the arithmetic unit 24 of the camera system 20. It is calculated using the following formula. l=(l+ΔZ/Z)×l1 However, the dimension Z is the height dimension from the horizontal reference plane 26 to the first one-point camera 21.

Therefore, even if the vehicle body 1 is vertically displaced from the horizontal reference plane 26, the horizontal position of the vehicle body 1 can be accurately detected. Note that the above explanation is about the first drain hole 16 and the first one-point camera 21, but this also applies to the third drain hole 18 and the second one point camera 21.
The same holds true for the one-point camera 22. In this way, the first drain hole 16 and the third drain hole 1
By measuring at least two positions 8, the positions of each part of the vehicle body 1 can be accurately determined.

(Second Embodiment) FIGS. 5 and 6 show a second embodiment. According to this, instead of the first one-point camera 21 in the first embodiment, a stereoscopic camera 4 is constructed of a pair of one-point cameras 40, 40.
1 is provided, and this stereoscopic camera 41 detects the position of the first drain hole 16 in the horizontal and vertical directions. Furthermore, the height dimension ΔZ of the fourth drain hole 19 is also detected in the same manner as in the first embodiment. Other configurations and functions are the same as in the previous embodiment, but
According to this embodiment, the positions of each part of the vehicle body 1 are three-dimensionally
This allows for a more accurate understanding. Although the above is based on the illustrated example, the contact sensor 27 may be provided separately from the industrial robot 12 or may be located above the vehicle body 1. Further, the camera may be provided below the vehicle body 1 or may be attached to the arm of the robot.

[0019]

[Effects of the Invention] According to the present invention, a camera system has a camera disposed above or below a detected part set as a part of a detected object, and the above camera system is recognized by the above camera. In the position detection device which detects the position of the detected part in the horizontal direction and outputs a detection signal, a contact sensor is provided for detecting the height of the detected part from a certain horizontal reference plane. Since the detection signal output from the camera system is corrected using the height detection signal from the contact sensor, even if a part of the vehicle body is shifted vertically from the horizontal reference plane,
The contact sensor that detects this shift allows the horizontal position of the object to be detected to be accurately detected. Therefore, the data corrected in this way is input to an industrial robot or the like, and subsequent work can be performed accurately.

[Brief explanation of drawings]

FIG. 1 is an explanatory view of the action taken along the line 1-1 in FIG. 2 in the first embodiment.

FIG. 2 is a plan view of the first embodiment.

3 is a partial sectional view taken along line 3-3 in FIG. 2 in the first embodiment; FIG.

FIG. 4 is an electrical wiring diagram in the first embodiment.

FIG. 5 is a diagram corresponding to FIG. 2 in a second embodiment.

FIG. 6 is a diagram corresponding to FIG. 4 in a second embodiment.

[Explanation of symbols]

1 Part of the vehicle body (detected object) 16 First water drain hole (detected part) 18 Third water drain hole (detected part) 20 Camera system 21 First one-point camera (camera) 26 Horizontal reference plane 27 contact sensor

Claims (1)

[Claims] Claim 1: A camera system includes a camera disposed above or below a detected part set on a part of the detected object, and the camera system is configured to detect the detected part recognized by the camera. In a position detection device that detects a position in a horizontal direction and outputs a detection signal, a contact sensor is provided to detect the height of the detected portion from a certain horizontal reference plane, and the height is determined by the contact sensor. A position detection device that corrects a detection signal output from the camera system using the detection signal.