JPH02284016A - Method and device for detecting inclination of work surface - Google Patents

Abstract

PURPOSE:To accurately detect a tilt angle without requiring the fitting accuracy of a laser light source by giving a laser light beam a parallel width and processing closed curve data generated with its external and internal edges. CONSTITUTION:The cylinder 15 of an image sensor stand 10 with a measurement plate is set at the center part of a hub and the measurement plate 11 is mounted on a tire 18. Further, the magnet 24 of a laser light source stand 20 is set by attraction at an optional position of a robot arm 29 and the position is adjusted by arms 21 and 22 so that a laser light source 23 can irradiates sideward an optional position which is greatly eccentric to some extent in the image pickup range of the measurement plate 11. Then while a camera device 13 picks up an image of the arm 29, one rotation is made and its light trace is processed by an attached arithmetic unit 30; and the tilt angle and tilt direction are detected from its elliptic shape and a tilt angle and direction signal is outputted to the robot. Consequently, the tilt angle of the arm 29 is adjusted finely to a slanting direction and the axis Q of rotation is adjusted to a direction which is parallel to the center axis R of the device 13, i.e. orthogonal to the measurement plate 11. In this state, the axis Q of rotation is aligned visually with the center axis R to accurately detect the tilt angle.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a work surface inclination detection method and device for detecting the inclination angle of the work surface with respect to the rotation axis of an automatic working machine such as a robot whose posture can be controlled. It is.

(Prior art) In addition to the method of visual inspection by one worker, this type of inclination detection method is based on the method of detecting inclination by checking the center point of a stationary automatic work machine, such as the tip of a robot arm, on which the work tool is attached, such that the center point coincides with the rotation axis of the work tool. A well-known method is to place a laser pointer on the work surface and determine the inclination based on the distortion of the reflected image formed on the work surface.

[Problem to be solved by the invention]

However, if the latter method using an optical device is used, it becomes possible to teach only one part of the product.

Accurate setting of the laser light source is required, which makes the setting structure complicated, and measurement is difficult when the work tool is attached to the robot arm.
Sometimes it became.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method and apparatus for detecting the inclination of a workpiece surface, which can automatically detect the inclination of the workpiece surface with high precision while setting a laser light source or in a cylinder.

[L stage for solving problems]

In order to achieve this purpose, the unfired 151 installs a laser light source that emits a laser beam toward the work surface on the work tool mounting part of an automatic work machine that can control the posture.
Work 1 By rotating the attachment part, a closed curve is drawn on the work surface using a laser beam, an image of the closed curve is captured by an image sensor to create closed curve data, and the work tool attachment part is drawn based on the ellipse shape obtained from this closed curve data. The purpose of this method is to detect the inclination angle of the work surface with respect to the orthogonal plane of the rotation axis.

To detect the inclination angle based only on the major axis of the ellipse, emit two parallel laser beams or a bundle of parallel laser beams from a laser light source toward the work surface, and detect the outer edge and inner edge closed curves corresponding to the light trails of the parallel laser beams. Create data, align the twists of the major axis of both elliptical shapes obtained from these outer edge and inner edge closed curve data, and calculate the inclination angle of the work surface from the distance difference between the major axis of the ellipse on both sides with respect to the width of the parallel laser beam. Detect.

As equipment for implementing such a slope detection method,
An image sensor stand with a measurement plate is equipped with an image sensor that images the measurement plate vertically above a flat measurement plate placed on the work surface, and a laser beam is directed toward the measurement plate at an angle to avoid the image sensor. A laser light source stand that is equipped with a laser light source that emits from a direction and is made of a single piece of magnetite that is adsorbed to the part where the work tool is attached, and a closed curve that is drawn with laser light on the measuring plate by rotating the part where the work tool is attached. An arithmetic device having a closed curve data creation means for creating closed curve data by inputting an image sensor signal taken by a sensor, and an inclination angle analysis means for analyzing the inclination angle of a measurement plate from this closed curve data and teaching an automatic working machine. Be prepared.

(Function) When a laser beam passes through the rotating shaft of the work tool attachment part, the rotating light trail becomes a conical shape of the single material of the laser light source relative to the rotating shaft, with a shape corresponding to the position and direction of light irradiation, while the rotating shaft If it does not pass through, it becomes an MRI hyperbolic rotation surface. However, in any case, the light trace on the work surface becomes a perfect circle if the angle of inclination is 0 degrees, and if the angle of inclination is 0 degrees, it becomes an ellipse with a shape corresponding to the degree of inclination. Therefore, the closed curve data is analyzed and the #1 angle of inclination is detected from the ellipse shape. For example, the angle of inclination is detected from the ratio of the major axis and minor axis of one ellipse corresponding to one laser beam. The direction of inclination can be seen from the major axis direction.

When two closed curve data are created from the inner and outer edges of the parallel laser beam, the torsions of the major axes of both ellipses are aligned, and the inclination of the work surface is determined from the distance difference between the major axes of the ellipses on both sides relative to the width of the parallel laser beam. Detect corners.

Regarding a device for carrying out such an inclination detection method, a measurement plate is placed on a workpiece surface, a laser light source stand is attracted to a work tool attachment part using a magnet, and a laser beam is emitted to the measurement plate. By rotating the attached part for each work, the closed curve drawn on the measurement plate by the laser beam is imaged by the image sensor. The arithmetic device creates closed curve data from the image sensor signal and analyzes the inclination angle of the measurement plate from the ellipse shape.

(Example) Fig. 1 shows an example of a device for carrying out the inclination angle detection method of Shukan 111, in which a tire 18 set in a tire setting jig 19 is used as a work tool attachment part of an automatic work machine. A hand arm 28 attached to a robot arm 29 is held and conveyed to place a position n at each predetermined work position.

In the figure, reference numeral 10 denotes an image sensor stand with a measurement plate, and an arm 12 is installed perpendicularly to a flat measurement plate 11 on its surface, and its tip supports an arm 14 to which a camera device I3 is attached in the horizontal direction. are doing. A positioning cylinder 15 inserted into the center four parts of the hub +8a on the back surface of the measurement plate 11 on the same axis -L as the central axis R of the camera lens.
It's been lowered.

Reference numeral 20 denotes a laser light source stand, and a laser light source 23 that emits, for example, two laser beams is attached to the lower end of an arm 21.22 connected by a rigid joint 26 whose position can be adjusted.
is attached to the upper end via a magnet 21 that is attracted to a robot arm 29 or a rigid joint 25 whose position can be similarly adjusted. Camera equipment! 3 includes a closed curve data creation means 31 that creates closed curve data by inputting an image sensor signal corresponding to a closed curve drawn on the measurement plate by rotating the robot arm 29, and calculates the inclination angle of the measurement plate from this closed curve data. and an arithmetic operation 1111Q having an inclination angle/direction analysis means 32 for analyzing the inclination direction and teaching the robot.

For measurement, use the image sensor stand 10 with measurement plate.
By setting the cylinder 15 in the center of the hub,
Place the measurement plate II on the tire 18 at a distance a.

On the other hand, the laser light source stand 20 attaches its magnet 24 to an arbitrary position of the robot arm 29, and attaches the laser light source 23 to the measurement plate 1 from the side. Arm 2 is arranged so that it can illuminate a somewhat largely eccentric position within the imaging range of
1.22 and position 3J.

Next, the robot arm 29 is rotated once while the camera device 2113 is taking an image, and the light trail is processed by the method described later on the attached arithmetic unit 0, and based on the elliptical shape, the angle of inclination is 0 and the direction of inclination is and outputs tilt angle and direction signals to the robot. Thereby, the inclination angle of the robot arm 29 is finely adjusted in the inclination direction, and its rotation axis Q is adjusted to be parallel to the central axis R of the camera device fill, that is, in a direction perpendicular to the measurement plate 11.

In this state, visually check the rotation axis Q of the robot arm 29.
to coincide with the camera center axis R. Therefore, even if there are irregularities on the tire surface, the slope of the standard surface can be detected.
At the same time, the deviation of the center position is also adjusted, so that from now on, the tire 18 set in the tire setting jig 1g is accurately transported to the working position δ using the hand arm 28.

As shown in FIG. 2, the performance equipment 30 emits two parallel laser beams 23. ．． The tilt state is detected as follows by inputting an imaging signal of a light trail formed by two laser light sources emitting 23□.

First, two pieces of closed curve data are created in the closed curve data creation means 31, but depending on the installation of the laser light source 23, the one rotation axis Q and the inner laser light 23. The outer laser beam Z32 is shifted by a certain angle e with respect to the direction between them, and therefore, as shown in No. 31Ab, the closed curve data of both ellipses 11. , there is an 11-gun attack in which the major axis direction of D2 is shifted by an angle e.

Therefore, the inclination angle/direction analysis means 32 rotates D2 by an angle e with respect to the ellipse, as shown in FIG. 4a. As a result, the center point P1 of both ellipses D+ and D*
, P2, regardless of whether or not the laser beam passes through the rotation axis Q, is aligned on a straight line with at least the intersection point P3 of Q with the rotation axis Q' in side view, and therefore the fourth point with respect to this rotation axis Q' in side view Analyze θ from the geometrical relationship shown in the figure.

γ=β + (90' α2) Here, d: Displacement A of P,, P2, A2: Long axis al+ of each of D, D,
1), : both ellipses D1. Long PI A on both sides of D2
Distance difference α2, α2 of r, A2: Work surface (
The angle of the measuring plate 11), ! l: Interval between thousand row Caesar beams γ° Angle of work surface with respect to rotation axis Q in side view Q: Inclination angle of work surface with respect to rotation axis Q From this relationship, Q is determined as follows.

a, = 5in-'(Jl/a+)a, =
sin-'(1/b+) α Corps + α3 =90° +0"-〇',', 0 = 90@ -α α 2 - α Furthermore, if the inclination direction is the major axis A+ or the corrected major axis 2 is calculated from the displacement angle of the image sensor stand with measurement plate 10 with respect to the reference installation direction.

In this embodiment, it is also possible to perform calculations by rotating D2 with a deviation based on the inner ellipse H, or by aligning Dl with respect to D2. In any case, the calculation is performed using only the data of both major axes. In the case of one laser beam, for example, Dl
The angle of inclination and the direction of inclination can be determined from the ratio of the major axis and minor axis. If the work surface is flat, it may be possible to directly image the light trace on the work surface without a measurement plate.

(Effects of the Invention) As described above, according to the present invention, the angle of inclination can be accurately detected by attaching a laser light source to the rotating tip of an automatic work machine without requiring high accuracy.

By processing closed curve data formed by the outer and inner edges of a laser beam with a width parallel to the laser beam, highly accurate position adjustment can be performed using only data in the major axis direction.

According to the apparatus according to claim 3, even if the work surface has irregularities, the inclination angle of the standard surface can be measured, and the light source is also easily attached and detached by magnet attraction without being restricted in position.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of a work surface inclination detection Stt device for carrying out the method of the present invention, and a block diagram of an attached circuit;
FIGS. 2 to 4 are diagrams for explaining the operation of the same embodiment. 1G-・Image sensor stand with measurement plate, 11-・
・Measurement plate, 20...Laser light source stand, 2t...
Laser light source, 24-...Magnet. 1st figure 77″￥7 tofu

Claims (1)

[Scope of Claims] 1) A laser light source that emits a laser beam toward a work surface is attached to a work tool mounting portion of an automatic working machine capable of controlling posture, and the work tool mounting portion is rotated to remove the workpiece. A closed curve is drawn on the surface by the laser beam, the closed curve is imaged by an image sensor to create closed curve data, and based on the elliptical shape obtained from the closed curve data, the A method for detecting inclination of a work surface, characterized by detecting an inclination angle of the work surface. 2) Emit two parallel laser beams or a bundle of parallel laser beams from a laser light source toward the work surface, create outer edge and inner edge closed curve data of the light trail of this parallel laser beam, and create data on the outer edge and inner edge closed curves obtained from these outer edge and inner edge closed curve data. 2. The inclination angle of the work surface is detected from the difference in distance between the long axes of the ellipses on both sides with respect to the width of the parallel laser beam, by aligning the twists of the long axes of both ellipses. Method for detecting inclination of work surface. 3) An image sensor stand with a measurement plate, which is equipped with an image sensor that images the measurement plate vertically above a flat measurement plate placed on the work surface, and an image sensor stand that faces the placed measurement plate and avoids the image sensor. A laser light source stand is equipped with a laser light source that emits a laser beam from an oblique direction, and a laser light source stand is attached with a magnet that attracts it to the work implement attachment part. Closed curve data creation means for creating closed curve data by inputting an image sensor signal obtained by imaging a drawn closed curve by the image sensor, and an inclination angle for analyzing the inclination angle of the measurement plate from the closed curve data and teaching the automatic working machine. 3. A workpiece surface inclination detection apparatus for carrying out the workpiece surface inclination detection method according to claim 1 or 2, further comprising an arithmetic unit having an analysis means.