JPS6353409A - Position detection of article - Google Patents

Abstract

PURPOSE:To achieve a highly accurate detection of position, by determining two virtual straight lines by using least square method based on a data indicating edge positions on two sides of a corner part to compare the position of intersection therebetween with a normal working position data. CONSTITUTION:An image taken with a TV camera 87 of an area 120 defined by two sides (a) and (b) of a corner part of a window glass A is taken into a processor in a control means 110, edge position a1, a2... and b1, b2... data of the sides (a) and (b) are measured and stored to determine an intersection P1 between virtual straight lines 121 and 122 approximate to the sides (a) and (b) using least square method and likewise, intersections P2-P4 are determined about other corners to calculate position coordinates. Then, the results are compared with the coordinates indicating a normal working position with respect to a working robot 88 corresponding to intersections P1-P4 to determine data errors between both the coordinates. Prior to a coating work, the data error is fed back to the robot 88 to correct coordinates at a teaching point thereby achieving a primer coating work for the glass A at a high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for detecting the position of an article for a manipulator that automatically works on an article having a corner portion.

(Prior Art) Conventionally, when an automobile window glass is attached to a car body using an adhesive, a paint called a primer is applied to the periphery of the window glass before applying the adhesive. The work of applying this primer was done by a robot like a robot! Since the process is performed by a manipulator that performs the work manually, if the position of the window glass shifts, the position where the primer is applied also shifts, so positioning the window glass accurately and quickly is an extremely important issue for quality control. was.

Conventionally, as disclosed in, for example, Japanese Unexamined Patent Application Publication No. 60-68079, first positioning has been carried out using mechanical positioning means that engages with the edge of the window glass.

However, the automobile window glass in -C is 2
Although one side is almost a straight line, the other two sides are curved, so positioning using edges must be accurate.Also, positioning based on corners may be difficult because some corners are curved. Moreover, since the radius of curvature varies and the corner points cannot be accurately defined, it is difficult to accurately position the window glass.

(Object of the Invention) In view of the above-mentioned circumstances, the present invention provides a method for detecting the position of an article having corners, such as a window glass, with high accuracy and speed, and improving the accuracy of a manipulator's work with respect to the article. The purpose is to provide a detection method.

(Structure of the Invention) In the method for detecting the position of an article according to the present invention, a plurality of edge positions on each of two sides of a corner portion of the article are measured, and from data indicating the positions of the plurality of edges, the method of detecting the position of an article is performed using the method of least squares. Find two virtual straight lines that approximate each of the two sides above, and compare the position data of the intersection of these two virtual straight lines with the regular working position data set in advance for the manipulator to determine the difference between the two. The present invention is characterized in that a data error is determined and this data error is fed back to the manipulator.

(Effects of the Invention) According to the present invention, two virtual straight lines each approximating the two sides of the corner portion of the article are determined using the least squares method based on the data of a plurality of edge positions on each of the two sides of the corner portion of the article.
The position data of the intersection of these two virtual straight lines is compared with the regular work position data set in advance for the manipulator to find the data error between the two.
The position of the article can be detected with high accuracy.

Furthermore, before the manipulator works, the data error can be fed to the manipulator to correct the coordinates of the manipulator's teaching point.
This manipulator can work on articles with high precision.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Figures 1 and 2 show the overall configuration of a positioning and conveying device for positioning and conveying a vehicle window glass A to which the article position detection method according to the present invention is applied in order to apply a primer to the outer periphery of the window glass A. In the figure, 1 is an incoming conveyor, 2 is an outgoing conveyor, and 3 is a shuttle conveyor installed between both conveyors 1 and 2. On the side of the downstream end of the carry-in conveyor 1, there is a first transfer device 4 for transferring the window glass A carried in by the carry-in conveyor 1 onto the shuttle conveyance device 3; A second transfer device 5 for transporting the window glass A transported by the shuttle transport device 3 to the unloading container 2 is installed in each of the windows.

First move! ! 2 device 4, as shown in FIG. 3 and enlarged in FIG.
6, and a connecting member 7 bridging the upper end of the support frame 8, which is formed into a gate shape. The arm member 11 is supported in a cantilevered manner so as to be able to slide between the upper downstream end of the shuttle transport device 3 and the upper upstream end of the shuttle conveyance device 3. The arm member 1 is attached to a sliding member 10 that is screwed into the sliding member 10, and the arm member 1 is moved from the downstream end of the deceased's conhair 1 to the upstream side of the shuttle conveyance device 3, or vice versa, by the drive i1i+ control of a motor (not shown). It is adapted to move along the screw shaft 9. Further, a fluid pressure cylinder 12 having a piston rod 12a extending downward is provided at the tip of the arm member 11, and a substantially H-shaped bracket 13 when viewed from above is rotatably attached to the lower end (tip) of the piston rod 12a. is supported by At the projecting end of this bracket 13,
Four rods 15, each having a suction pad 14 at its lower end for suctioning the window glass A at four points, are suspended and supported in a state in which they are constantly urged downward by the biasing force of a coil spring attached around the rods. Each suction pad 14 is connected to a vacuum pump (not shown). By controlling the operation of the air pump, the window glass,
It is designed to attract and hold objects from above.

Further, a moving cylinder 17 (having a piston loft 17a extending horizontally) is attached to the lower surface of the arm member 11 via a bracket I6, and the tip of this piston rod 1.7a is connected to the rotation of the bracket 13. It is connected to the shaft via a link (not shown), and each suction pad 14 is rotated by 90'' around the rotation axis by the telescoping action of the mechanical cylinder 17, and moved up and down by the telescoping action of the fluid pressure cylinder 12. It is done like this.

Further, since the second transfer device 5 has the same configuration as the first transfer device 4 described above, duplicate explanation will be omitted.

On the other hand, as shown enlarged in FIGS. 5 to 7, the shuttle conveyance device 3 includes a single guide rail member 1 installed so as to bridge the carry-in conveyor 1 and the carry-out conveyor 2.
The guide rail member 18 has a first arm 20 whose upper end is swingably pivoted via a shaft 19 near its upstream end (close to the carry-in conveyor 1), and a first arm 20 near its downstream end (close to the loading conveyor 1).
It is horizontally supported at a predetermined height position from the floor by a second arm 22 whose upper end is swingably pivotally connected via a shaft 21 to the unloading container 2).

The first arm 20 is bent into a substantially "<" shape, and its bent portion is pivotally attached to the upper ends of the pair of support plate members 23 and 23 so as to be rotatable around the horizontal support shaft 24, and the lower end thereof is is pivotally connected to the connector 25 via a shaft 26 so as to be swingable. A tip of a piston rod 27a of a horizontally extending hydraulic cylinder 27 is connected to one end of the connector 25. Further, another fluid pressure cylinder 28 is disposed at a position opposite to the fluid pressure cylinder 27, and this cylinder 28 is provided so as to be able to press the other end of the coupling tool 25 with a piston rod 28a extending in the horizontal direction. It is being Then, the first arm 20 is rotated around the support shaft 24 by the expansion and contraction operations of both of the fluid pressure cylinders 27 and 28, and the guide rail member 18 is moved to the upper height position when the window glass A is transported, which will be described later. The height is adjusted in three levels: a middle height position during the coating operation and delivery of the window glass A, and a lower height position during the retreat operation by gloss conveyance and positioning of the window glass A. On the other hand, the second arm 22 has its lower end pivotally attached to a pair of support plate members 29 so as to be swingable about a horizontal axis 30, and is adapted to be linked to the swing vJ movement of the first arm 20.

Further, on the guide rail member 18, as shown in FIG. being carried.

Further, a screw shaft 34 is provided below the guide rail member 18 and extends horizontally along its longitudinal direction.
A drive shaft of a motor 35 is connected to one end of the screw shaft 34 . In addition, the screw shaft 34
A sliding member 36 is screwed onto the sliding member 36, and a retaining bin 37 is provided horizontally protruding from the sliding member 36, and the first and second conveyance platforms 31, 32 are attached to the retaining bin 37. Engagement groove 3 of engagement plate member 3B extending downward from connection plate 33 to be connected
8a is engaged and the motor 35 is not activated? 1+J to rotate the screw shaft 34 and slide the sliding member 36.
And the first and second conveyance tables 31, 32 integrated therewith are shuttle conveyed along the longitudinal direction of the guide rail 18.

As shown in FIGS. 6 to 9, buffer support members 39 made of an elastic material such as rubber are fixedly installed at the four corners of the upper surfaces of the first and second conveyor tables 31 and 32, and in the vicinity thereof. A suction band 40 for suctioning and holding the window glass A on the back surface thereof is arranged. The arrangement state of each suction pad 40 on the first conveyance table 31 will be explained in detail. ), each suction pad 40 is fixed to the upper end of the lot 41 as shown in an enlarged view in FIG. Cylindrical body 43 facing
It is supported by being inserted into.

The cylindrical body 43 is attached to the first carrier 31 via a bracket 44, and a fluid pressure cylinder 45 having a piston rod 45a extending downward is attached to the bracket 44. is connected to the lower end of the rod 41 via a connecting member 46, and the suction pad 40 is moved up and down by the expansion and contraction operation of the fluid pressure cylinder 45. In addition, a coil spring 47 is used for the lower half of the mouth and door 41.
is attached, and the biasing force of this spring 47 prevents the suction pad 40 from moving upward rapidly when the fluid pressure cylinder 45 is contracted. Also,
Each suction pad 40 is connected to a vacuum pump (not shown), and when the vacuum pump is operated, the window glass A
It is designed so that it can be held by suction from below. These components constitute a suction conveyance means that suction holds and conveys the window glass A.

A positioning station 318 for positioning the window glass A is provided on the upstream side of the shuttle transport device 3, and an unloading station 49 is provided on the downstream side. Each work station 50 is provided for applying the coating material. These stations 48.49.
50 are installed at equal intervals, and the adsorption p
The first conveyance table 31 serving as a conveying means is located at the positioning station 4.
When the 119th conveyance table 31 is located at the work station 50, the second conveyance table 32 is located at the work station 50, and when the 119th conveyance table 31 is located at the work station 50, the second conveyance table 32 is positioned at the unloading station 49. ing.

As shown in FIG. 1, FIG. 2, and FIG.
And, the positioning station 48 is moved by the first transfer device 4.
First to fifth positioning devices 51 to 55 are installed as positioning means for positioning the window glass A transferred onto the first I:4 carriage 31. 1st
The positioning device 51 includes an arm member 57 that is attached to a column 56 so as to be movable up and down by an operating mechanism (not shown) and extends horizontally at the center of the positioning station 48. As shown in the enlarged view, a guide plate member 61 is fixed via three rods 58 to 60. Inside this guide plate member 61, a sliding rod 64.65 is slidably inserted into two upper and lower holes 62 extending in the horizontal direction, and a shaft is rotatably inserted between these two sliding rods 64.65. Supported by each suribokuchi
7 part part 64. Formed in the longitudinal middle part of 65, 2
The large gear 6 meshes with the rib portions 64a, 65a and the tooth portion 63a.
3 are provided, and both sliding rod members 64 and 65 are slid in mutually opposite directions by the forward and reverse rotational operations of the large gear 63. In addition, both sliding rond members 64
．． A roller 67 is rotatably supported at one end of each roller 65 via a bracket 66 on a support shaft 68 in the vertical direction. Note that each sliding rod member 64, 65 is loosely fitted into a hole 66a of a bracket 66 fixed to the other sliding rod member 65, 64, respectively.

Further, the tip of a piston rod 69a of a horizontally extending hydraulic cylinder 69 provided on the guide plate member 61 is fixed to one bracket 66 (on the left side in the figure), and when the hydraulic cylinder 69 expands and contracts, large gear 6
3 to bring both rollers 67 into contact with and away from each other. in this case,
When the cylinder 69 is telescopically operated, the large gear 63 is rotated counterclockwise in the figure to move both rollers 67 away from each other, while when the fluid pressure cylinder 69 is retracted, the large gear 63 is rotated clockwise. By rotating the rollers 67 in the direction shown in FIG. In addition, large gear 63
A small gear 70 is engaged with the rollers 67, and a pickup (not shown) detects that both rollers 67 come into contact with the outer periphery of the window glass and the rotational load on the small gear 70 increases. The contraction operation of the fluid pressure cylinder 69 is stopped.

On the other hand, among the second to fifth positioning devices 52 to 55,
As shown in FIG. 9, the 2.3 positioning device 52.53
is arranged on one side (lower side in the figure) of the base rail part (18th) and serves to set the positioning reference for the window glass on the first conveyance platform 31, while the 4.5 positioning device 54 and 55 are arranged on the other side (upper side in the figure) of the guide rail member 18 and are connected to the second and third positioning devices 52 and 53.
This serves to position the window glass A whose circumference has been aligned to the positioning reference position on the first FG feed table 31, and these positions the window glass in the vertical direction.

Since both the second positioning device 52 and the third positioning device 53 are formed in the same structure, and the fourth positioning device 54 and the fifth positioning device 55 are also formed in the same structure,
Here, in each case one of the 2.4 positioning devices 52.5
Regarding the other 3.5 positioning v2 position 53.55, the same parts are given the same reference numerals and detailed explanation thereof will be omitted.

The second positioning device 52 includes a sliding bar 73 provided horizontally in a direction perpendicular to the guide rail member 18 by a pair of supporting members 72 on a fixed table 71 of the positioning station 48, and a rodless member that moves on this bar 73. This rodless cylinder 74
A positioning member 76 that pivotally supports the roller 75 is fixed to the positioning member 76, and this positioning member 76 moves on the fixed table 71 while being guided by a guide rail 77 by the operation of the rodless cylinder 74, thereby moving the roller 75 to the first position. The window glass A on the conveyor table 31 is moved in a direction toward and away from the outer periphery of the window glass A. In addition, first and second sensors 78 and 79 are respectively mounted on the fixed table 71 on the outside of the positioning member 76 via a mounting member 80, and when the rodless cylinder 74 moves forward, the positioning member 76 When the protruding piece 81 contacts the first sensor 78, the forward movement of the rodless cylinder 74 is stopped and the roller 75 is moved to the reference position for positioning the window glass A. On the other hand, when the protruding piece 81 comes into contact with the first sensor 78, the protruding piece 81
comes into contact with the second sensor 79, the loftless cylinder 74
The retracting operation of the roller 75 is stopped and the roller 75 is moved to the standby position.

Also, like the second positioning device 52, the fourth positioning device 54 is configured to move the roller 75 forward or backward by the ff-movement of the rodless cylinder 74. Further, a third sensor 82 is attached on a fixed table 84 behind the roller 75 via a mounting member 83, and the positioning member 76 of the roller 75 comes into contact with the third sensor 82 when the rodless cylinder 74 moves backward. When it comes into contact with the roller 75, the backward movement of the Rondo cylinder 74 is stopped and the roller 75
is moved to a standby position.

Further, a rack 85 is attached to the positioning member 76 of the fourth positioning device 54, and a pinion 86 that meshes with the rack 85 is rotatably supported on the fixed table 84, and the roller 75 is connected to a rodless cylinder. 74
When the rack moves forward and comes into contact with the outer periphery of the window glass A on the first conveying table 31, this contact causes the rack 8 to move forward.
An unillustrated pickup detects an increase in the rotational load on the pinion 86 that meshes with and rotates with the pinion 5, and the operation of the rodless cylinder 74 is stopped based on this detection signal.

The first
The window glass A on the conveyance table 31 is positioned in the horizontal direction by the first positioning device 51, and in the vertical direction by the second to fifth positioning devices 52 to 55, respectively.

Further, on the positioning station 48 side, the first to
5. Four visual sensors 87 each consisting of a television camera are arranged as position detection means for detecting the position of the window glass A positioned by the positioning devices 51 to 55 (specifically, the positions of the four corners of the window glass A). The position signal of the window glass A after positioning detected by these visual sensors 87 is transmitted to the control means 110, and the signal outputted from this is transmitted to the articulated work robot 88 as a work means provided at the work station 50. It is designed to output to .

After being positioned at the positioning station 48, the work robot 88 is moved to the work station 50 by the first conveyance platform 31.
Primer is applied to the outer periphery of the window glass A that has been transported by shuttle.

In addition, regular work data for the window glass A at the work station 50 is stored in advance in the control means 110, and the coating work is performed on the window glass A based on this regular work position data. Is there any regulation during this coating work? In the II1 means 110, positioning data is determined based on the position signal at the positioning station 48 of the window glass A inputted from each visual sensor 87 as described above, and this positioning data is compared with the regular working position data. A data error is determined, and the regular work position data stored in the robot 88 is corrected using this data error as a correction value.

This corrected regular work position data is stored in memory until the positioned window glass A is conveyed to the work station 50, and is output to the robot 88 after the window glass A is conveyed to the work station 50. It is made to be done.

Here, we will discuss the first method for detecting the position of window glass A.
To explain in more detail with reference to the configuration diagrams of FIGS. 3 to 15 and the flowchart of FIG. 16, first, one corner of the window glass A shown in FIG. 2 sides a of the part
. This is the equipment that it has. The image processing device converts the captured image signals into Figure 14 (
As shown in b), a plurality of edge positions a, , a, , a, ---1 are measured for each edge of one side a, and the position data of these positions is determined and stored. Similarly, for the edges on the other side, multiple edges are located, ,b,
, b, ---- in total 4 (1), and calculate and store these position data (step S2).Next, from the data indicating these edge positions, using the least squares method, as shown in FIG.
As shown in b), find two virtual straight lines 121 and 122 that approximate the two sides a and b, respectively (step S3), then find the intersection P1 of both virtual straight lines 121 and 122, and calculate its position coordinates. (Step S4). By applying this method to other corner portions, the intersections P2, P3, and P as shown in FIG. 15 are obtained.

If the position coordinates of the four intersection points P, -P, are found (
(determination in step S5), the working robot 8
8 is compared with the position coordinates indicating the normal work position set in advance corresponding to the above-mentioned intersections P, .about.P, and a data error between both position coordinates is determined (step 36). Alternatively, as shown in FIG. 15, calculate the intersection point Q between the straight line connecting the intersection points P and 23 and the straight line connecting the intersection points P2 and P4, and calculate the position coordinates of this point Q <x+, y+>. A data error between the two position coordinates may be determined by comparing the position coordinates indicating the normal work position set in advance for the working robot 88 corresponding to the point Q. And robot 88
Prior to the primer application work by the robot 88, the data error is fed back to the robot 8 (step S7), and the coordinates of the teaching point of the robot 88 are corrected, so that the primer application work to the window glass A by the robot 88 can be performed with high accuracy. can be done.

As shown in FIG. 9, in the work station 50, a plurality of suction pads 89, two each in pairs, are attached to a fixed table 93 on the side of the second IM conveyor 32 (first conveyor 31).
It is attached to 94. Each suction band 89 has an eleventh
As shown in enlarged detail in FIG. 12 and FIG.
is attached to the fixed table 9 via the bracket 92 so that the suction pad 89 protrudes above the fixed table 93.94.
It is attached to 3.94. In addition, the bracket 92
A piston rod 95a extending downward is provided between the two cylindrical bodies 90.
A piston rod 95a of this fluid pressure cylinder 95 is connected to a connecting member 96.
The suction pads 89 are connected to the lower ends of the rods 91 via the rods 91, and both suction pads 89 are moved up and down by the expansion and contraction operations of the hydraulic cylinders 95. When each suction pad 89 rises due to the contraction operation of each fluid pressure flip 95, the robot 88 at the work station 50 suction holds the window glass 8 on the first conveyance table 31 on which the coating work has been completed and lifts it upward. On the other hand, when the suction pads 89 are lowered due to the extension work of each fluid pressure cylinder 9S, the window glass A held by suction is released from the suction action of each suction pad 89 and transferred to the second vIj and onto the carriage 32. It is made to be. Each suction pad 89 is also connected to a vacuum pump (not shown), and the window glass A is suctioned and held from below by controlling the operation of this vacuum pump. Further, a coil spring 97 is installed in the lower half of each rod 91 to prevent the suction pad 89 from rapidly moving upward when the fluid pressure cylinder 95 is contracted.

A sensor 98 sets the lowering position of the suction pad 89.

The above describes the method for detecting the position of a window glass A that implements the method for detecting the position of an article according to the present invention, and the method when this method is applied to a positioning and conveying device that positions and conveys the article in order to apply a primer to the outer periphery of the window glass. As an explanation, according to the above embodiment, a plurality of edge positions 1 a l , a z , , a * respectively determined on the two sides a and b at the corner to the window glass are
Using the least squares method from the data of ""-'- and bl, b2, b, -, ---, find virtual straight lines 121 and 122 that approximate the above two sides a, b, respectively, and Based on the coordinates of the intersection point P1 of the straight lines 121 and 122 and the coordinates of the intersection points P2, P3, and P4 of the other corners obtained in the same way, the data is compared with the regular work position data set in advance for the robot 88. Since the data error between the two is determined, the position relative to the window glass can be detected with high accuracy.

Furthermore, before the work robot 88 performs the primer application work, the data error is fed back to the robot 88 so that the coordinates of the teaching point of the robot 88 can be corrected, and the primer application work by the robot 88 can be performed with high precision. Can be done.

[Brief explanation of drawings]

1 to 12 show a positioning and conveying device to which the present invention is applied, which positions and conveys the vehicle window glass in order to apply a primer to the outer periphery. FIG. 1 is a plan view showing a schematic configuration, and Figure 2 is its front view, Figure 3 is an enlarged side view of the first transfer device, Figure 4 is an enlarged plan view of its main parts, Figure 5 is an enlarged front view of the shuttle transport device, and Figure 6 is its An enlarged front view of the main part, No. 7 (2I is an enlarged vertical side view of the same), Fig. 8 is an enlarged front view of the main part showing the suction band arrangement part of the first conveyance table, and Fig. 9 is a positioning station part and work station. Enlarged plan view of the part, Figure 1O is the 1st
Fig. 11 is an enlarged front view of the main parts of the positioning device, Fig. 11 is an enlarged front view showing the suction pad placement part of the fixed table on the work station side, Fig. 12 is an enlarged side view of the same, and Fig. 13 is the plane of the window glass. 14 and 15 are explanatory diagrams showing the procedure for implementing the method of the present invention, and FIG. 16 is a flowchart showing the method of the present invention. 18-Guide rail member 31-th] transport stand 32-.-
Second conveyance table 40 - Suction pad 48 - Positioning station 50 - One working station 51 to 55 - First to fifth positioning device 67.75... Roller 87 - Visual sensor 88-1l:, Port>, To 110-Control means Am/Window glass 121.122...-Virtual straight line

Claims (1)

[Claims] A method for detecting the position of an article for a manipulator that automatically works on an article having a corner portion, the method comprising detecting a plurality of edge positions on each of two sides of the corner portion of the article. Based on the data shown, find two virtual straight lines using the least squares method, compare the position data of the intersection of these two virtual straight lines with the regular working position data set in advance for the manipulator, A method for detecting the position of an article, characterized in that the data error is fed back to the manipulator.