JPH02311703A - Position detecting method - Google Patents

Abstract

PURPOSE:To detect a position accurately by applying water soluble fluorescence agent on a detecting position, projecting light on the applied position from an ultra-violet lamp, and binary-coding the picked-up image. CONSTITUTION:When a vehicle body 3 is conveyed into an inspecting station, light is projected on water soluble fluorescence agent 5 which is applied in the vicinity of a detecting position e.g. a bolt hole 4 from an ultraviolet lamp 6. The image is picked up with a camera. The picked up image is inputted into a control unit and processed. Then, the binary coordinate values of the image are outputted. Correction for assembling coordinate position is instructed to an assembling unit. Thus the accurate assembling work can be performed. At this time, the high sensitivity image in the visible light region appears by the projection of the light from the lamp 6 on the fluorescence agent 5. Meanwhile, since the sensitivity of the bolt hole 4 itself where the fluorescence agent 5 is not applied is low, the definite contrast is obtained even if the projecting angle is changed. The stable image is obtained even under the disturbance from other lamps. Thus the position detecting accuracy is stabilized, and the reliability is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a position detection method, and more particularly, to a method for accurate position detection by applying a water-soluble fluorescent agent to a detection position.

[Conventional technology]

Conventionally, when parts are assembled at an automobile assembly station using an assembly means such as an assembly robot, it is necessary to accurately detect the position of the vehicle body after it has been brought into the work position. Then, based on the position information, the corresponding positions of the parts are corrected to ensure accurate assembly work.

To detect this position, a reference point set on the vehicle body and its surroundings are illuminated with lighting lamps, etc., and an image is taken with a camera.
A commonly used method is to import the image into a control unit and process the image. That is, by binarizing the captured image, it is read out as coordinate values.

[Problems to be Solved by the Invention] By the way, in position detection using image processing as described above, subtle changes in imaging conditions, such as the occurrence of shadows due to changes in the irradiation angle of illumination, changes in illuminance due to other illumination, etc. Therefore, an accurate image cannot be obtained, and detection accuracy may deteriorate. Therefore, in order to always obtain a clear image, measures are taken such as applying paint to the periphery of the detection position and making the background color constant. However, when applying paint, there are problems such as color unevenness, which disrupts the image, or paint that scatters to other parts, reducing the product value.

The present invention has been made in consideration of these circumstances, and is capable of always detecting accurate positions even when there are subtle changes in imaging conditions, and does not reduce product value due to overspray or the like. , our objective is to provide a position detection method.

[Means to solve the problem]

In order to solve the above problems, the position detection method of the present invention has the following features:
A water-soluble fluorescent agent is applied around the detection position, the applied area is irradiated with an ultraviolet lamp, the irradiated area is imaged by a camera, and the imaged image is binarized.

[For production]

Even if there are subtle changes in imaging conditions, the water-soluble fluorescent agent coated around the detection position is irradiated with an ultraviolet lamp, achieving high sensitivity in the visible light range and eliminating the effects of external disturbances. It is possible to always capture a clear image and perform accurate position detection without any interference. The applied water-soluble fluorescent agent is completely washed away when it is washed with water in a separate process.

〔Effect of the invention〕

The position detection method of the present invention involves applying a water-soluble fluorescent agent around the detection position, irradiating the applied area with an ultraviolet lamp,
The irradiated area is imaged with a camera, and the captured image is 2
Since it is converted into a value, it is possible to always capture a clear image and perform accurate position detection. The applied fluorescent agent is then washed away with water in a separate process, and the painted color does not remain on the car body, so the product value does not decrease.

〔Example〕

EMBODIMENT OF THE INVENTION Below, this invention is demonstrated in detail based on the drawing which shows the Example.

The position detection method shown in this embodiment is adopted at an automobile assembly station, and detects
The assembly robot is designed to accurately detect the position of bolt holes on the vehicle body when assembling suspension parts, and is carried out as follows.

As shown in FIG. 1, when the vehicle body 3 is carried into the inspection station 2 located upstream of the assembly station 1, the bolt hole 4 of the vehicle body 3 (see FIG. 2) which becomes the detection position
A water-soluble fluorescent agent 5 applied in advance is irradiated around the area by an ultraviolet lamp 6, and the irradiated area is imaged by a camera 7. The TI image is taken into the control unit 8, subjected to so-called image processing, read out as binarized coordinate values, and
Based on the detected data, an assembly work unit 1-1 disposed at the assembly station 1 is used to assemble the engine and front suspension assembly 9 and the rear suspension assembly 10 to the vehicle body 3. 11. Correction of the assembly coordinate position is commanded for 12, and accurate assembly work is performed. This assembly work unit 11.12 is equipped with a lifting cylinder device and a position adjustment cylinder device,
Tables lla and 12a that are movable up and down and within a plane
Assemblies each placed on top 9. It is configured such that the assembly coordinate position of IO can be adjusted arbitrarily.

The fluorescent agent 5 applied around the bolt hole 4 produces a highly sensitive image in the visible light region when irradiated with the ultraviolet lamp 6, while the sensitivity of the bolt hole 4 itself, which is not coated with the fluorescent agent 5, is Even if the irradiation angle of the ultraviolet lamp 6 changes, a clear contrast can be obtained. Therefore, extremely stable images can be captured even in the face of disturbances caused by other lighting, etc., and the accuracy of position detection through image processing is stabilized, making it highly reliable.

In the present invention, by including the fluorescent agent in a water-soluble fluid such as water, it is possible to easily apply it to the car body 3 by spraying, and also to leave it as it is after imaging, so that it can be applied to the car body 3 in a later process. I try to wash it away when I wash it with water. Furthermore, unlike conventional paints, there is no risk of overspray resulting in a decrease in product value.

Note that the present invention does not apply to positions other than the bolt holes to be assembled,
For example, it goes without saying that it can be applied to detecting the position of a reference point appropriately set on a vehicle body (for example, a protrusion, a recess, or a point or location that can be distinguished by a difference in its thin shape), and other general position detection.

[Brief explanation of drawings]

FIG. 1 is a system configuration diagram of the position detection method of the present invention, and FIG.
The figure shows a fluorescent agent coated on the outer surface of a bolt hole being irradiated with an ultraviolet lamp. 4-・Detection position (bolt hole), 5-・Water-soluble fluorescent agent,
6- UV lamp, 7- camera. Patent Applicant Mazda Motor Corporation Agent Patent Attorney Katsutoshi Matsuki (and 1 other person) Figure 2

Claims (1)

[Claims] (1) A water-soluble fluorescent agent is applied around the detection position, the applied area is irradiated with an ultraviolet lamp, an image is taken with a camera, and the taken image is binarized to detect the position. A position detection method characterized by: