JPH0758441B2 - Robot position correction method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention has a tool holder provided with a plurality of tools corresponding to a plurality of work points of a work, which is provided on the working end of a robot through a support shaft. The present invention relates to a robot position correcting method and apparatus for moving the tool holder to a predetermined teaching position by the operation of the robot and performing work by the tools at the work locations.

(Prior Art) Conventionally, a plurality of robots each equipped with a dedicated liquid supply nozzle are used as an automatic liquid supply device for a plurality of tanks such as an automobile radiator tank and a cleaning liquid tank, and each robot is used as teaching data. Therefore, it is known that the liquid supply nozzles are operated to insert the liquid supply nozzles into the liquid supply ports of the respective predetermined tanks to perform the liquid supply work.

However, in this case, the equipment cost is high, and it is necessary to sequentially operate the robots in order to avoid interference between the robots, and there is a problem that work efficiency is reduced. Attach a tool holder equipped with multiple liquid supply nozzles corresponding to multiple tanks via a spindle,
By operating the robot, the tool holder can be moved to a predetermined teaching position where each of the liquid supply nozzles faces the liquid supply port of each tank, and a single robot can efficiently supply liquid to these tanks at the same time. I created a device that can be used.

(Problems to be Solved by the Invention) By the way, as described above, a robot equipped with a tool holder equipped with a plurality of tools (liquid supply nozzles) corresponding to a plurality of work locations (liquid supply ports) of a workpiece (automobile) is used. In the case of performing automatic work by performing the automatic work, a problem is how to perform the position correction for the position shift of the work.

That is, when the center line of the front-rear direction of the work is not set so as to accurately face the front-rear direction, each tool can be moved to each working position simply by moving the robot in two directions orthogonal to the front-rear direction and the lateral direction. It does not match and it is necessary to rotate the tool holder around the spindle according to the inclination of the work, and the position of the tool holder should be corrected by comprehensively detecting the displacement and inclination of the work in two orthogonal directions. Is required.

An object of the present invention is to solve such a problem and to make it possible to accurately and easily correct the position of a tool holder.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the first invention of the present application uses a spindle of a tool holder provided with a plurality of tools corresponding to a plurality of work locations of a workpiece at the working end of a robot. A robot position correction method in which the tool holder is moved to a predetermined teaching position by the operation of the robot and the work is performed by the tool at each work location. Among them, a measuring frame in which at least two tools and the supporting shaft are arranged in the same layout as the two locating members and the measuring shaft, which engage with each other at two work locations corresponding to the two tools, is used. , When the positions of the measuring shaft and the locate members coincide with the positions of the support shaft and the tool at the teaching position, the locate members are engaged with the working locations. Of measuring axis A feature is that a displacement amount and a rotational displacement angle amount of the measurement frame around the measurement are detected, and the teaching position is corrected according to the detected value.

A second invention of the present application provides an apparatus used for carrying out the method of the first invention, wherein both of the orthogonal coordinates in which the measuring frame is set on a plane orthogonal to the spindle at the working end of the robot. The measurement is performed while being mounted so as to be movable in the coordinate axis direction and rotatable about the measurement axis, and having a point on the surface orthogonal to the support axis in a predetermined positional relationship with the support axis as the origin of the orthogonal coordinates. Positioning means for positioning the frame so that the measuring axis matches the origin and the rotational phase of the measuring frame around the measuring axis matches the rotational phase of the tool holder around the spindle at the teaching position. And a detection means for detecting a displacement amount of the measurement axis in the directions of both coordinate axes and a rotational variation angle of the measurement frame around the measurement axis with reference to a positioning state by the positioning means, and operating the robot. The measurement frame by the original Is movable to a predetermined measurement position that matches the position of the support shaft at the teaching position, and at the measurement position, the locating member is moved to each working position while the positioning of the measurement frame by the positioning means is released. And a means for correcting the teaching position in accordance with a detection value of the detecting means when the locate members are engaged with the respective work places.

(Operation) The operation of the present invention will be described with reference to FIG.

In the figure, A ₁ and A ₂ are the positions of both tools in the teaching position, that is, the positions of two working points when the work is accurately set, A ₁ ′ and A ₂ ′ are the actual positions of both working points, and B Indicates the position of the support shaft when the tool holder is moved to the teaching position, and C, D ₁ and D ₂ indicate the positions of the support shaft and the two tools at the time of displacement measurement described later by the measuring frame. The measurement axis is set in a position such that the rotation phase around the measurement axis matches the rotation phase of the tool holder around the spindle at the teaching position at the teaching position.
When the two locate members are aligned with A ₁ and A ₂ , the positions of the two locate members are A ₁ ′, and the positions of the two locate members are A ₁ ′,
The measuring frame is displaced to A ₂ ′, the position of the measuring axis is displaced from B to B ′ accordingly, and the measuring frame rotates around the measuring axis.

Thus, the displacement amounts Δx and Δy from B to B ′ and the rotational variation amounts Δθ of the measuring frame are detected, the teaching position is corrected according to the detected value, and the tool holder is moved to the above. From phase △
If the tool is rotated about the spindle by θ and moved so that the spindle matches B ′, the positions of both tools will match A ₁ ′ and A ₂ ′. Can be obtained.

Further, according to the position of the second aspect of the invention, the measuring frame is positioned by the positioning means, the measuring frame is moved to the measuring position by the operation of the robot, and then the constraint of the measuring frame is released by the positioning means and both locates. The displacement amounts Δx and Δy and the displacement amount Δθ can be detected by the detection means only by engaging the means with both working locations, and the position can be corrected quickly.

(Example) With reference to FIG. 2, (1) is an automobile as a work, (2)
Indicates a robot arranged in front of the set position of the automobile (1), and the first liquid supply port (1a) for radiator liquid arranged in the engine room of the automobile (1) by the robot (2).
And a second liquid supply port (1b) for power steering oil,
The third liquid supply port (1c) for the cleaning liquid is used as a working point to perform the liquid supply work to these liquid supply ports (1a) (1b) (1c).

The robot (2) is a rail (3a) that is long in the front-rear direction.
A robot arm (5) swingable in the vertical direction via a swivel base (4) is provided on a slide base (3) that can be moved back and forth along (3a), and the tip of the arm (5) is always horizontal. The wrist (6) held in the posture is attached, and the tool holder (8) is axially brought into contact with the wrist (6) via the spindle (7) perpendicular to the wrist (6), and the tool holder (8) shown in FIG. as shown in Figure 5, the liquid supply port (1a) (1b) first to tertiary nozzle corresponding to _{(1c) (9 1) (} 9 2) (9 3) respectively Units - cylinder (9
a) by those composed mounted vertically movably, the robot (2) respective nozzle (9 ₁ to the tool holder (8) by operation of) (9 ₂₎ (9 ₃₎ of respective liquid supply port ( 1a) (1b) (1c) is moved to a predetermined teaching position facing directly above, and in this state, each nozzle (9 ₁ ) (9 ₂ ) (9 ₃ ) is moved downward to cause each liquid supply. It was inserted into the mouths (1a) (1b) (1c) to perform the liquid supply work.

Incidentally, respective nozzles (9 _1, 9 ₂₎ (9 _3), a pair of penetrating the respective Units - cylinder (9a) piston rod (9b)
Lifting frame (9b) connected to both ends of (9b) at both upper and lower ends.
It was supposed to be hung on c) via a rubber mount (9d).

By the way, if the vehicle (1) is not correctly set to the set position, when the tool holder (8) is moved to the teaching position, the liquid supply nozzles (9 ₁ ) (9 ₂ ) (9 ₃ ) are supplied with the respective liquid supply nozzles. The mouth (1a) (1b) (1c) does not match, and it becomes impossible to perform liquid supply work.

Therefore, in the illustrated example, the three liquid supply nozzles (9 ₁ )
Same as the layout of the first and second liquid supply nozzles (9 ₁ ) (9 ₂ ) and the support shaft (7), which are relatively widely separated from each other (9 ₂ ) and (9 ₃ ). Both nozzles in the layout of (9 ₁ )
(9 ₂ ), corresponding to the first and second liquid supply ports (1a)
Two locate members (10 ₁ ) (10 ₂ ) that each engage with (1b)
A measuring frame (12) in which the measuring axis (11) and the measuring axis (11) are arranged is prepared, and the measuring frame (12) is placed on the tool holder (8) in a rectangular coordinate set on a horizontal plane orthogonal to the spindle (7). Coordinate axis direction or X
The measuring frame (12) is provided so as to be movable in the axial direction and the Y-axis direction and rotatable about the measuring axis (11), and the measuring frame (12) is measured before the tool holder (8) is moved to the teaching position. axis (11) and both said locating member (10 ₁₎ (10 ₂₎ of said supporting shaft (7) and the first second supply fluid nozzle (9 ₁₎ of the tool holder (8) in Teichingu position (9 ₂ ) To a predetermined measurement position that matches the position of ( ₁ ), and in this state, the both locate members (10 ₁ ) (10 ₂ ) are engaged with the first and second liquid supply ports (1a) (1b). At this time, the amount of displacement of the measurement axis (11) in the X-axis direction and the Y-axis direction and the amount of rotational displacement of the measurement frame (12) around the measurement axis (11) are detected, and according to the detected values. To correct the teaching position.

In the illustrated example, the origin 0 of the Cartesian coordinates is located ahead of the spindle (7) in the moving direction of the robot (2) toward the automobile (1), and the origin 0 and the spindle (7) are located. Set so that the line connecting to and the Y-axis match, and then hold the tool holder (8).
As shown in FIGS. 6 and 7, a first slider (13a) slidable in the X-axis direction and a second slider slidable in the Y-axis direction on the first slider (13a). A cross slider (13) composed of (13b) is provided so that its neutral point coincides with the origin 0, and the measurement axis (1) is attached to the second slider (13b).
1) is erected, the measurement frame (22) is rotatably supported by the sleeve (12a) at the root of the measurement shaft (11), and thus the cross slider is attached to the measurement frame (12). Movement in the X-axis direction and Y-axis direction by (13), and the measurement axis (11)
It is designed to be able to rotate around.

Further, as shown in FIG. 4, positioning holes (14a) formed in the tool holder (8) on both sides of the root of the measuring frame (12).
A taper pin (14b) fitted to the cylinder (14c) is provided so as to be movable up and down to form a positioning means (14), and by fitting the pin (14b) into the hole (14a), the measurement shaft ( 1
1) coincides with the origin 0, and the rotation phase of the measurement frame (12) around the measurement axis (11) becomes the rotation phase of the tool holder (8) around the spindle (7) at the teaching position. The measurement frame (12) can be positioned in a matched state, and thus the origin 0 is taught by the operation of the robot (2) with the measurement frame (12) positioned by the positioning means (14). The position of the support shaft (7) and the first and second liquid supply nozzles (9 ₁ ) (9 ₂ ) at the teaching position can be obtained by moving the support shaft (7) to a predetermined measurement position that matches the position of the support shaft (7). The measurement axis (11) and the locating members (10 ₁ ) (10 ₂ ) can be aligned with each other.

Further, on the tool holder (8), the displacement amount of the measuring axis (11) in the X-axis direction and the Y-axis direction and the measuring frame (12) around the measuring axis (11) based on the positioning state. ) Is provided with a detecting means for detecting the rotational displacement amount, and in detail, as shown in FIGS. 6 to 8, the tool holder (8) is provided.
A displacement detector (15) in the X-axis direction having a pinion (15b) that engages with a rack (15a) fixed to the first slider (13a), and a second slider (1) on the first slider (13a).
Pinion (16b) that engages with the rack (16a) fixed to 3b)
A displacement detector (16) in the Y-axis direction attached with the measuring frame (1) as shown in FIGS. 3 and 4 on the second slider (13b).
A rotation angle detector (17) having a rod (17b) that abuts a fixed lever (17a) is provided on the sleeve (12a) of 2), and detection means is provided by these detectors (15) (16) (17). Configured.

Further, the measuring frame (12) is provided with an elevating frame (12d) which is vertically moved by a cylinder (12c) along a linear guide (12b) at the tip of the root part, and the elevating frame (12d) has an arm member (12d).
Both of the locate members (10 ₁ ) and (10 ₂ ) are attached via e).

The locating members (10 ₁ ) (10 ₂ ) are configured such that three engaging members (10a) extending downward can be opened and closed in a radial direction by an opening and closing actuator (10b). The first liquid supply port (1a)
The first locate member (10 ₁ ) engaging element (10 a) of the first locate member (10 ₁ ) in the contracted state is inserted into the liquid supply port (1 a) as shown in FIG. The first locate member (10 ₁ ) is centered and engaged with the liquid port (1a), and the engaging element ( ₂ ) of the second locate member (10 ₂ ) is engaged with the second liquid supply port (1b). 10a) as shown in FIG. 13, the second liquid supply port (1b)
The second locating member (10 ₂ ) is centered and engaged with the second liquid supply port (1b) by contracting the expanded state so as to enclose the above.

The gap between the liquid supply ports (1a) and (1b) may not reach a predetermined value due to the mutual displacement of the liquid supply ports (1a) and (1b). (1
0 ₁₎ (so as to vary the spacing 10 _2), the first locator member (10 ₁₎ a measurement frame to (12) both said locating member (1
It is movable in the wire connection direction of 0 ₁ ) (10 ₂ ).

The details are as shown in FIGS. 9 to 11, and the support frame (18) in which the first locate member (10 ₁ ) is attached to the fixed frame (12f) fixed to the arm member (12e) is provided. An openable and closable 1 which is slidably supported through a linear guide (18a) in the connection direction and further holds a pin (19a) standing on the end of the support frame (18) on the fixed frame (12f). Pair of gripping claws (19b)
Is provided with a positioning member (19), and the first locate member (10 ₁ ) is moved to the second locate member (1) by the member (19).
0 ₂ ) can be positioned at a regular position such that the distance to the predetermined value becomes the predetermined value, and the fixed frame (12) is attached to the support frame (18).
A plurality of limit switches (20) that cooperate with the fixed dog pieces (20a) are provided in f), and the first locating member (10 ₁ ) is unconstrained by the positioning member (19) to release the first liquid closing port (19). 1a) The first locate member (10 ₁ ) when engaged with
The amount of displacement from the normal position of was detected.

The first liquid feed nozzle (9 _1), as shown in Figure 3 and Figure 5, the nozzle relative to the lifting frame (9c) which in the bracket of the hanging Jisuru rubber mount (9d) (9e) ( 9 ₁₎ and the second supply fluid nozzle (9 ₂₎ along connexion slidably supported on the linear guide (9f) in the connection direction between, first by a pair of small single-acting cylinder (9 g) (9 g) The liquid supply nozzle (9 ₁ ) is displaced in the connection direction by the amount of displacement of the first locate member (10 ₁ ), and the distance between the both nozzles (9 ₁ ) (9 ₂ ) is set to both liquid supply ports (1 a ) (1b) is adapted to match.

In addition, as shown in FIG. 12, a detection is performed in which a fixed frame (12g) fixed to the arm member (12e) to which the second locate member (10 ₂ ) is attached is inserted into the third liquid supply port (1c). Rod (21
A detection cylinder (21) to which a) is attached is provided, and both locating members (10 ₁ ) (10 ₂ ) are connected to the first and second liquid supply ports (1a) (1b).
The rod (21a) is moved downward while being engaged with the
If the rod (21a) does not move down to a predetermined position due to contact with the edge of the rod (21a) due to displacement of the liquid supply port (1c), liquid supply to the third-class liquid port (1c) is not possible. It was to stop the liquid supply operation by the third supply fluid nozzle (9 _3).

Further, wherein the second locator member (10 ₂₎ of each engaging element (10a), as shown in Figure 12 and Figure 13, the second liquid supply ports (1b)
The arc-shaped wire rod (10
c) were installed by shifting the positions vertically so that they do not interfere with each other when contracting and closing.

In the drawing, (22) shows a sensor for checking the opening / closing of the bonnet, which is attached to the tip of the measuring frame (12). When the bonnet is not open, the forward movement of the measuring frame (12) is stopped. .

Next, the operation of the above embodiment will be described.

After the automobile (1) is set in at the set position, the measurement frame (12) is first positioned by the positioning means (14) and moved to the measurement position by the operation of the robot (2).

According to this, the positions of the measuring shaft (11) of the measuring frame (12) and the first and second locate members (10 ₁ ) (10 ₂ ) are the supporting shaft (7) of the tool holder (8) at the teaching position. It matches the position of the first second supply nozzle (9 ₁₎ (9 _2), then the measurement frame (12) lifting frame (12d) is lowered to in the both locating member (10 ₁₎ (10 ₂₎ After the rough engagement with the first and second liquid supply ports (1a) (1b), the measuring frame (12) by the positioning means (14)
And the locate members (10 ₁ ) (10 ₂ ) are centered and engaged with the liquid supply ports (1a) (1b). In this case, the position of the first and second liquid supply ports (1a) and (1b) is displaced from the normal position shown by A ₁ and A ₂ in FIG. ₁ to A ₁ ′ and A ₂ ′ due to the displacement of the automobile (1). Then, the positions of the locate members (10 ₁ ) (10 ₂ ) are displaced to A ₁ → A ₁ ′ and A ₂ → A ₂ ′, respectively, and the position of the measuring axis (11) is changed to B. → When it is displaced to B ', the axis (1
1) The measuring frame (12) rotates around.

Then, the displacement amounts Δx and Δy of the measurement axis (11) in the X-axis direction and the Y-axis direction and the rotational displacement angle Δθ of the measurement frame (12) are detected by the detectors (15) (16). This value Δx, detected by (17),
The teaching position is corrected according to Δy and Δθ, that is, the position of the support shaft (7) at the teaching position is Δx and Δy.
Along with the displacement in the X-axis direction and the Y-axis direction, the rotational phase of the tool holder (8) is changed by Δθ, and the tool holder (8) is moved to this correction position.

According to this, the measuring shaft (11) and the first second locator member (10 ₁₎ (10 ₂₎ of the same layout and layout of the support shaft (7) and the first second supply fluid nozzle (9 ₁ ) (9 ₂ ) matches B ′, A ₁ ′, and A ₂ ′, respectively, and the nozzles (9 ₁ ) (9 ₂ ) are surely inserted into the liquid supply ports (1a) (1b) by descending. can also third supply fluid nozzle (9 ₃₎ can also be inserted into the third liquid supply ports by tank installation error unless fed-liquid inlet is not greatly positional deviation (1c) (1c), 3 pieces thereof Te nuclear Liquid supply port (1a) (1b) (1
It is possible to efficiently feed liquid to c) at the same time.

It is also possible to attach a supporting plate, which is separate from the tool holder (8), to the wrist (6), which is a single unit of the operation of the robot (2), and to mount the measuring frame (12) on it. As described above, it is advantageous to mount the measuring frame (12) on the tool holder (8) because the number of parts can be eliminated and the weight can be reduced.

Further, the present invention is of course applicable to robots other than the above-mentioned robots for liquid supply work.

As described above, according to the method of the present invention, even if the work is tilted and set, the position of the tool holder can be easily corrected so that the plurality of tools of the tool holder match the plurality of work locations. Further, according to the apparatus of the second aspect of the invention, the position can be corrected quickly, and the working efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the principle of the present invention, FIG. 2 is a plan view of a robot for liquid supply work to which the present invention is applied, FIG. 3 is an enlarged plan view of a main part thereof, and FIG. 4 is its right side. Fig. 5 is a side view as seen from the line V-V in Fig. 3, and Fig. 6 is VI- in Fig. 3.
VI sectional side view, FIG. 7 is a VII-VII sectional plan view of FIG. 6, FIG. 8 is a VIII-VIII sectional sectional view of FIG. 7, and FIG. 9 is an enlarged plan view of the first locate member. , Fig. 10 is its front view,
11 is a side view taken along the line XI-XI of FIG. 10, FIG. 12 is an enlarged cross-sectional view of the second locating means, and FIG. 13 is a bottom view thereof. (1) …… Automobile (work) (1a) (1b) (1c) …… Liquid supply port (working point) (2) …… Robot, (7) …… Spindle (8) …… Tool holder (9 ₁ ) (9 ₂ ) (9 ₃ ) …… Liquid supply nozzle (tool) (10 ₁ ) (10 ₂ ) …… Locating member (11) …… Measuring axis, (12) …… Measuring frame (14) …… Positioning means (15) (16) …… Displacement detector (detection means) (17) …… Rotation angle detector (detection means)

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Claims (3)

[Claims] 1. A tool holder having a plurality of tools corresponding to a plurality of work locations of a work is axially provided on a working end of a robot via a spindle, and the robot operates to bring the tool holder into a predetermined teaching position. A method for correcting the position of a robot, in which the work is performed by the respective tools at the respective work places, the layout layout of at least two of these tools and the supporting shaft being the same. In the layout, a measuring frame in which two locate members that engage with each other and two measuring positions corresponding to the two tools are arranged is used, and the positions of the measuring shaft and the locate members are the positions in the teaching position. The displacement amount of the measuring shaft and the rotational change of the measuring frame around the measuring shaft when the locate members are engaged with the working places with reference to the state where the positions of the support shaft and the both tools are matched. Angle and Position correction method for a robot, characterized in that to perform the correction of the Teichingu position according to the detection value. 2. A tool holder provided with a plurality of tools corresponding to a plurality of work points of a work is axially provided on a working end of a robot through a support shaft, and the tool holder is moved to a predetermined teaching position by the operation of the robot. A position correcting apparatus for a robot, which is moved to a position where the work is performed by each tool at each work location, and has the same layout as the layout of at least two of these tools and the spindle. A measuring frame in which two locate members that can be engaged with each other and a measuring axis are arranged at two work points corresponding to the tools in the layout is set on a plane orthogonal to the supporting axis at the working end of the robot. The rectangular coordinate system is mounted so as to be movable in both coordinate axis directions and rotatable about the measuring axis, and a point on the plane orthogonal to the spindle is in a predetermined positional relationship with the spindle. Use the measurement frame as the origin Positioning means that is positionable such that the measurement axis matches the origin and the rotation phase of the measurement frame around the measurement axis matches the rotation phase of the tool holder around the spindle at the teaching position. The measuring means is provided with a detecting means for detecting a displacement amount of the measuring axis in the directions of both coordinate axes and a rotational displacement amount of the measuring frame around the measuring axis with reference to the positioning state by the means, and the measuring is performed by the operation of the robot. The locating member is provided with the frame movable to a predetermined measurement position where the origin coincides with the position of the support shaft in the teaching position, and the positioning of the measurement frame by the positioning means is released at the measurement position. And a means for correcting the teaching position according to a detection value of the detecting means when the locate member is engaged with each work location. Position correction apparatus for a robot, characterized in that the. 3. The position correcting apparatus for a robot according to claim 2, wherein the measuring frame is mounted on the tool holder so that the origin is located at a position offset from the support shaft.