JPH06127444A - Hub boltposition detecting device - Google Patents

Abstract

PURPOSE:To provide a hub bolt position detecting device by which a hub bottle position is excellently detected. CONSTITUTION:When a front hub FH is photographed by cameras 38 and 40, only a light source 42 arranged in a direction approximately coinciding with the photographing direction of the camera 38 is lighted ON through control of a robot controller 14 and a light source 44 is lighted OFF. After the front hub FH is photographed by the camera 38, conversely, only the light source 44 is lighted ON and the light source 42 is lighted OFF, and the front hub is photographed by the camera 40. Thus, when the front hub is photographed respectively by the cameras 38 and 40, light from the light sources 44 and 42 located on the opposite side thereto is reflected by a hub surface and not read at image information. Further, since a hub bolt is not shaded on an image, a hub bolt position is excellently detected through processing of an image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hub bolt position detecting device for detecting a hub bolt position on a hub surface of a vehicle body when mounting wheels on the vehicle body in an automobile assembly line or the like.

[0002]

2. Description of the Related Art In the automobile manufacturing industry, an automatic assembly system for attaching parts to a vehicle body transported on an assembly line by using an industrial robot has been promoted. In a wheel mounting robot that automatically mounts wheels on a hub, a CCD camera or the like is used to detect the hub bolt position. Then, the wheels are mounted on the vehicle body based on the hub bolt position information confirmed by the camera.

In this case, the hub is illuminated by the illumination means,
By increasing the illuminance of the hub surface and the hub bolt, a good image of the hub is read by the camera, and the position of the hub bolt is detected by performing image processing on the read image of the hub.

[0004]

When such a hub bolt position detecting method is applied, when the illumination light from the illumination means becomes specularly reflected light by the hub or the vehicle body and is captured by the camera, an image of the hub bolt is displayed. There is a risk that it may become unclear, resulting in erroneous or unrecognizable positions of the hub bolt. Then, the actual Kaihei 1-9068
By shutting off the illuminating means that may capture specularly reflected light by the camera, such as Japanese Patent Laid-Open Publication No. 0-Hub bolt position detecting device for automobiles, with a shutter,
A device that suppresses the influence of reflected light has been proposed.

However, even if the regular reflection light is not taken into the camera, depending on the position of the illumination means, a part of the hub bolt is shaded in the image picked up by the camera so that a good image is obtained. It could not be obtained, which might affect the detection of the position of the hub bolt.

The present invention has been made in order to solve this kind of problem, and an object of the present invention is to provide a hub bolt position detecting device which can detect the hub bolt position satisfactorily.

[0007]

In order to achieve the above-mentioned object, the present invention is a device for detecting the position of a hub bolt for mounting a wheel, wherein the hub bolt protrudes from the hub surface. A pair of image pickup means disposed at different image pickup angles, a pair of illumination means that substantially match the image pickup directions of the respective image pickup means and illuminate the hub surface, and a substantially same image pickup direction as the image pickup means during image pickup. Only the lighting means to turn on,
Lighting control means for controlling other lighting means to be turned off.

[0008]

According to the hub bolt position detecting device of the present invention, when the control means takes an image of the image pickup means, only the illumination means which substantially coincides with the image pickup direction of the image pickup means is turned on, and the other illumination means is turned off. Therefore, the light from the other illuminating means does not become specularly reflected light on the hub surface or the like and is not read by the imaging means. Further, since the illuminating means substantially coincides with the image pickup direction of the image pickup means, the hub bolt does not become a shadow in the image to be picked up, and good image information of the hub surface is obtained. The position can be detected well.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A hub bolt position detecting device according to the present invention will be described in detail below with reference to the accompanying drawings with reference to preferred embodiments.

FIG. 1 is a plan view showing the outline of the construction of a wheel mounting robot system including a hub bolt position detecting device of the present invention, and FIG. 2 is a front view of the system.

The wheel mounting robot system 10 includes a robot body 12 for assembling wheels W on a vehicle S conveyed on an assembly line, a robot controller 14 for outputting control signals and the like to the robot body 12, and an arithmetic unit 16 including a computer and the like. , A CCD imaging camera (hereinafter, simply referred to as a camera) 18 for reading an image of the front hub FH of the vehicle S fixed by a tripod, a camera 20 for reading an image of a rear hub RH, and image information output from the cameras 18, 20. An image processing device 22 that reads and arithmetically processes this image information is provided. The cameras 18 and 20 perform rough sensing of the front hub FH and the rear hub RH.

A nut supply robot 26 and a wheel mounting robot 28 are arranged on the pedestal portion 24 of the robot body 12, and the nut supply robot 26 grips a nut for fixing the wheel W from the parts feeder 30 and mounts the wheel. The robot 28 holds the wheels W placed in the wheel storage 32,
Attach to the front hub FH and rear hub RH. The wheel mounting robot 28 includes an arm 34 and a chucking unit 36. The chucking unit 36 is substantially aligned with the cameras 38, 40 and the hub imaging directions of the cameras 38, 40, respectively, and is located behind the cameras 38, 40. And the chuck 4 for holding the wheel W therebetween.
6, 48.

The arithmetic unit 16 is, as shown in FIG.
A CPU 50, a robot interface 52 connected to the robot controller 14, an illumination control circuit 54 for controlling the timing of turning on and off the light sources 42 and 44, and a camera control circuit 56 for controlling the cameras 38 and 40 are provided.
The hub image information read by the cameras 38 and 40 is arithmetically processed by the CPU 50 of the image processing device 22.

In the wheel mounting robot system 10 configured as described above, the center coordinates of the hub attached to the vehicle S, the inclination of the toe angle of the hub and the like, and the phase of the hub bolt are detected to detect the wheel. The operation of attaching W to the hub will be described with reference to the flowchart of FIG.

The vehicle S to which the wheels W are attached is conveyed to a predetermined position near the wheel attachment robot system 10. The image information of the front hub FH of the vehicle S is read by the camera 18 and output to the image processing device 22 (step S1).

The image processing device 22 calculates the center coordinates of the front hub FH from the input image information of the front hub FH and the preset coordinates of the camera 18 (rough sensing), and outputs the calculation result to the calculation device 16. It is output to the robot controller 14 via the device (step S2).

The robot controller 14 drives the arm 34 of the robot body 12 based on the information indicating the center coordinates of the front hub FH to displace the chucking unit 36 attached to the arm 34 in the front hub FH direction. (Step S3). Chucking unit 36
Is such that the center lines of the two cameras 38 and 40 arranged at the tip end coincide with the center coordinates of the front hub FH, and the maximum angle of view of the cameras 38 and 40 is the front hub FH.
When it matches the H image, the displacement is stopped.

The cameras 38 and 40 are operated by the front hub FH based on a command from the camera control circuit 56 of the arithmetic unit 16.
The enlarged image information of is read and output to the image processing device 22 (step S4). At this time, as shown in FIG. 5, first, when the front hub FH is imaged by the camera 38, only the light source 42 is turned on and the light source 44 is turned off under the control of the illumination control circuit 54 of the arithmetic unit 16. Therefore, there is no possibility that the light from the light source 44 is specularly reflected by the front hub FH or the like and read into the image of the camera 38. Further, since the hub surface is illuminated by the light from the light source 42 that substantially matches the imaging direction of the camera 38, the hub bolt 60 reaches a predetermined illuminance, and
A shadow is not formed on the side surface 60a and the head portion 60b of the hub bolt imaged by the camera 38. Therefore, the camera 3
The image of the hub surface and the hub bolt is read into the image processing device 22 from 8 in good condition. Subsequently, when the camera 40 takes an image of the front hub FH, the same effect can be obtained by turning on only the light source 44 and turning off the light source 42 under the control of the illumination control circuit 54 of the arithmetic unit 16.

The image processing device 22 scans the image information to certify the head of the hub bolt by image processing, obtains the coordinates of the certifying points, and outputs the data of the center coordinates of the respective certifying points to the computing device 16. Output (Step S
5).

The computing device 16 computes new central coordinates O of the front hub FH, which will be described later, the toe angle θ of the hub, and the phase of the hub bolt from the data of the central coordinates of the certified points (step S6). That is, an elliptical orbit that is close to the head of the hub bolt 60 recognized by the cameras 38 and 40 is selected from a plurality of preset elliptical orbits formed by connecting the heads of the hub bolts. The toe angle θ of the hub is calculated based on these elliptical orbits, and the hub bolt 6
The phase of the hub bolt 60 is calculated from the head position of 0.

Next, it is judged whether or not the toe angle θ of the hub is less than or equal to a preset angle α (step S7), and θ
If <α, the center coordinates O of the front hub FH, the toe angle θ of the hub, and the phase information of the hub bolt 60 are output to the robot controller 14.

The robot controller 14 urges the wheel mounting robot 28 of the robot body 12 based on the center coordinate O of the front hub FH, the toe angle θ of the hub, and the phase information of the hub bolt 60, and the chucking unit 3 is operated.
The wheels W sandwiched by 6 are attached to the front hub FH of the vehicle S (step S8).

On the other hand, when θ <α is not satisfied in step S7, that is, when the toe angle θ is inclined by a preset angle α or more, the wheel W and the body around the hub are attached when the wheel W is attached to the hub. Since there is a possibility that the wheels will come into contact with each other and the wheel W cannot be mounted, an alarm is sounded (step S9), the operation of the wheel mounting robot system 10 is interrupted, and the toe angle θ is corrected.

In step S8, when the wheel W is attached to the front hub FH, the fixed camera 20 reads the image information of the rear hub RH and performs the rough sensing of the rear hub RH. Next, the wheels W are attached to the rear hub RH by the same operation as in steps S1 to S7 (step S10).

As described above, according to the hub bolt position detecting device of the present embodiment, when the front hub FH is imaged by the camera 38, only the light source 42 is turned on and the light source 44 is turned off under the control of the arithmetic unit 16. , Light source 4
The light from 4 is not reflected on the hub surface and read into the image of the camera 38. Further, since the light source 42 is substantially aligned with the image capturing direction of the camera 38, the hub bolt 60 is not shaded in the image information read by the camera 38 by the light from the light source 42. In the case of the camera 40, only the light source 44 is turned on under the control of the arithmetic unit 16. Therefore, the image information read from the cameras 38 and 40 is not affected by the light from the light sources 44 and 42 on the opposite side, and the hub bolt 60 is not shaded. The position can be detected accurately.

It should be noted that the cameras 38, 40 serve as illumination means.
If a ring-shaped light is provided around the image pickup lens, the shadows of the cameras 38 and 40 will not be formed on the hub surface,
Image recognition can be performed even better.

[0027]

According to the hub bolt position detecting device of the present invention, the following effects can be obtained.

That is, since the control means controls only the illuminating means which is substantially coincident with the image pickup direction of the image pickup means to be turned on and the other illuminating means to be turned off when the image pickup means picks up the image from the image pickup means. The light becomes specularly reflected light on the hub surface or the like and is not read by the image pickup means. Further, since the illuminating means substantially coincides with the image pickup direction of the image pickup means, the hub bolt does not become a shadow in the image to be picked up, and good image information of the hub surface is obtained. The position can be detected well.

[Brief description of drawings]

FIG. 1 is a plan view showing a schematic configuration of a wheel mounting robot system including a hub bolt position detecting device according to the present invention.

FIG. 2 is a front view showing a schematic configuration of a wheel mounting robot system including a hub bolt position detecting device according to the present invention.

FIG. 3 is an explanatory diagram of an arithmetic circuit of the hub bolt position detecting device according to the present invention.

FIG. 4 is a flowchart showing an operation of attaching a wheel to a hub by the system of FIG.

FIG. 5 is an explanatory view of a hub surface illumination state of the hub bolt position detecting device according to the present invention.

[Explanation of symbols]

 10 ... Wheel mounting robot system 12 ... Robot main body 14 ... Robot controller 16 ... Computing device 18, 20, 38, 40 ... Camera 42, 44 ... Light source 54 ... Lighting control circuit 56 ... Camera control circuit

Claims (1)

[Claims] 1. A device for detecting the position of a hub bolt for mounting a wheel, comprising: a pair of imaging means arranged at different imaging angles with respect to a hub surface from which the hub bolt is projected; A pair of illuminating means that illuminate the hub surface substantially coincident with the image capturing direction of the means, and only the illuminating means whose image capturing direction substantially coincides with the image capturing means being imaged are turned on, and the other illuminating means are turned off. A hub bolt position detection device, comprising: a lighting control unit for controlling.