JPH08281582A - Calibration method of industrial robot - Google Patents

Abstract

PURPOSE: To simply carry out a calibration process by only using a standadized jig indicating a work point A, so as not to generate an error even in the case of transferring a robot. CONSTITUTION: A horizontal arm swinging shaft S3, a wrist rotating shaft S4, and a wrist swinging shaft S5 are operated, a work point A is positioned on the first mark M1 on a vertical arm so as to set a first calibration posture, and it is corrected based on the reference angles θ3 *-θ5 * corresponding to the detected angles θ3 -θ5 of the respective shafts S3-S4. A base revolving shaft S1 and a vertical arm swinging shaft S2 are operated, the work point A is positioned on the second mark M2 on the fixed part of a base so as to set a second calibration posture, and it is corrected based on the detected angles θ1 /θ2 and the reference angles θ1 */θ2 * of the base revolving shaft S1 and the vertical arm swinging shaft S2 at the posture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for calibrating an industrial robot which corrects the detection angle of each axis such as a vertical arm swing axis based on a reference angle.

[0002]

2. Description of the Related Art Most industrial robots such as welding robots have a teaching playback system (teaching / reproducing system).
Has been adopted. The teaching playback method operates the robot in a teaching mode in which a program including a sequence of teaching points is created and in a playback mode in which teaching points are moved in accordance with the created program. (Work) is usually performed by the operator operating the teaching pendant to actually move the robot to the teaching point and storing the posture (angle of the joint axis) when the robot moves to the teaching point in the robot. .

However, in recent years, in order to complete the teaching work as easily as possible, a virtual robot or work is displayed on a display screen of a computer, and a program is created offline using this display screen. Or, a standard program created in advance by a robot maker using another robot is diverted.

In such a case, there is a machine difference between a teaching robot for program creation (a virtual robot on a computer or another robot used by a robot maker) and a robot for actual work in which the program is reproduced. If there,
Even if the angle of the joint axis at the time of teaching is reproduced, the problem that the posture is not accurately reproduced occurs.

Therefore, when the teaching work is performed off-line or the like, a calibration process for adjusting the machine difference between the robots is performed. Specifically, the calibration process is performed by positioning the tip of the arm at the reference position and correcting each axis of the arm, and then positioning the tip of the wrist at the reference position and correcting each axis of the wrist. (Japanese Patent Laid-Open No. 5-1
No. 6083), a calibration process is carried out by attaching a position correcting jig to each of the fixed part and the tip of the wrist of the robot body and measuring the displacement with a dial gauge. 31
No. 661).

[0006]

However, in the above conventional method, it is necessary to provide the reference position separately from the robot main body from the viewpoint of aligning the tip of the arm portion with the reference position and the viewpoint of the robot structure. When the robot main body is relocated, if there is an error in the relative position between the reference position and the robot main body, there is a problem that an error will occur in the correction of the calibration processing of the robot main body. There is also a problem that a special jig for calibration processing, such as a jig attached to the arm portion, is required, and work such as attachment and detachment is required for each calibration processing.

Further, in the case of the method (1), the position correction can be performed by the robot alone.
There is a problem that a special jig for position correction is required, and the measurement work with the dial gauge reduces workability.

Therefore, an object of the present invention is that the calibration process can be easily performed without using a special jig for calibration and only by using a standard jig that indicates a working point. The object of the present invention is to provide a calibration method that does not cause an error in correction even when a robot is relocated.

[0009]

In order to solve the above-mentioned problems, the detected angles of a base swing shaft, a vertical arm swing shaft, a horizontal arm swing shaft, a wrist rotation shaft and a wrist swing shaft are based on a reference angle. A method for calibrating an industrial robot, which corrects each of them, wherein a working point is positioned at a first reference position on a vertical arm by operating the horizontal arm swing axis, the wrist rotation axis, and the wrist swing axis. With the first calibration posture, the detection angles of the horizontal arm swing axis, the wrist rotation axis, and the wrist swing axis in this posture are obtained, and these detected angles are corrected based on the reference angles corresponding to these detected angles. Operating the base swing axis and the vertical arm swing axis while maintaining the horizontal arm swing axis, the wrist rotation axis, and the wrist swing axis in a predetermined posture using the corrected detection angles. Therefore, the working point is set to the second calibration position in which it is positioned at the second reference position on the fixed part of the base, and the detection angles of the base turning axis and the vertical arm swinging axis in that position are calculated, and the detected angles are dealt with. It is characterized in that each of these detected angles is corrected based on the reference angle.

[0010]

According to the above arrangement, the working point is positioned at the first reference position on the vertical arm, and the working point is positioned at the second reference position on the fixed portion of the base. By adopting the two-calibration posture, the detection angles of all axes are corrected. Therefore, the working point can be obtained with a standard jig, and the positioning of the working point can be performed by the same operation as the teaching work, so that the correction of the detection angles of all axes can be easily completed.

Further, the first reference position and the second reference position used for correction are set on the vertical arm of the industrial robot and the fixed portion of the base, respectively. Therefore,
Even when the industrial robot is relocated, the positional relationship between the robot and the first reference position and the second reference position is always constant, so that no error occurs in correction.

[0012]

【Example】

[Embodiment 1] An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the calibration method according to the present embodiment is adapted to be implemented in an industrial robot which is a vertical articulated robot having substantially five degrees of freedom as a whole. This robot includes a base swivel axis S1 (θ ₁ ) including a fixed part that rotates around a vertical axis and a swivel base, and a vertical arm swing that swings a vertical arm back and forth mounted on the base swivel axis S1. Axis S2
(Θ ₂ ) and a horizontal arm swing axis S3 (θ ₃ ) attached to the free end side of the vertical arm swing axis S2 and swinging the horizontal arm up and down, and a free end side of the horizontal arm swing axis S3. Is attached to the wrist rotation shaft S4 (θ ₄ ) that rotates coaxially with the horizontal arm to rotate the wrist, and a wrist swing shaft S5 (θ that bends the wrist attached to the free end side of the wrist rotation shaft S4.
₅ ) and have.

A welding torch 6 is provided on the free end side of the wrist swing shaft S5 via a torch fitting, and the tip of the welding torch 6 is adjusted to indicate an arc point (working point A). A chip 7 is provided. A first mark M ₁ (first reference position) is formed on the vertical arm or the lower arm that constitutes the vertical arm swing axis S2.
The mark M ₁ is used as a positioning point of the adjustment tip 7 when the robot takes the first calibration posture shown in FIG. In addition, the base turning axis S
A second mark M ₂ (second reference position) is formed on the fixed portion constituting No. 1, and the second mark M ₂ is for adjustment when the robot takes the second calibration posture of FIG. 3. It is designed to be used as a positioning point for the chip 7. Incidentally, the above-mentioned first mark M ₁ and second mark M ₂
May be one in which the base material is shaved to locally form a flat surface portion, and a + mark or the like is formed on this flat surface portion by engraving or scribing, or is formed by a metal fitting with a sharp tip. Is also good.

The shafts S1 to S5 described above are driven by drive motors 10a to 10e, as shown in FIG. Each drive motor 10a-10e has a shaft S
Angle detectors 11a to 11e for detecting the angles 1 to S5 are connected, and these angle detectors 11a to 11e are connected.
Is the detection angle θ _{1 with} respect to the calculation unit 14 of the controller 12.
It outputs ~ ₅ .

The controller 12 has a storage unit 15 connected to the arithmetic unit 14. In addition, this storage unit 1
5 is preferably composed of a nonvolatile and writable storage element such as an EEPROM, but may be composed of a RAM backed up by a battery or the like depending on the configuration of the apparatus, and further, an external storage such as a floppy disk. It may consist of a device.

The storage unit 15 stores the horizontal arm swing axis S3, the wrist rotation axis S4, and the wrist swing axis S5 in the first calibration posture in which the working point A coincides with the first mark M ₁ . Reference angle θ ₃ ^*・ θ ₄ ^*・ θ ₅ ^*
(In the case of an offline program, the value that the virtual robot should detect in the same posture, in the case of the standard program created by the robot manufacturer, the value that the robot of the manufacturer should detect in the same posture) and the work point A Reference angle θ with respect to the base pivot axis S1 and the vertical arm swing axis S2 in the second calibration posture that is aligned with the 2 mark M ₂ .
A reference angle storage area 15a for storing ₁ ^* · θ ₂ ^* and a correction value storage area 15b for storing correction values Δθ _{1 to} Δθ ₅ are formed. Then, the calculation unit 14 of the controller 12 executes the below-described first and second calibration processes to detect the detection angles θ _{1 to} θ ₅ indicating the current position of the robot and the reference angle θ ₁ described above.
Calculate the difference from ^* ~ θ ₅ ^* as correction values Δθ ₁ ~ Δθ ₅ ,
Based on the correction values Δθ _{1 to} Δθ ₅ , the detected angles θ _{1 to} θ ₅
The robot is controlled by using the corrected detection angles θ ₃ 'to θ ₅ ' which are corrected.

The reference angles θ ₁ ^{* to} θ ₅ ^* may be the detection angles θ _{1 to} θ ₅ of the respective axes at the time of calibration at the initial installation of the robot. In this case,
It is possible to correct the deviation that has occurred since the beginning of installation.

In the above structure, the correction values Δθ _{1 to} Δθ
A calibration method for obtaining ₅ will be described.

First, as shown in FIG. 1, the operator operates the teaching pendant to operate the base pivot S.
1 and the vertical arm swing axis S2 are set to appropriate angles. It should be noted that the angle may be any posture that facilitates the first calibration process, such as a posture in which the base turning axis S1 faces the front and the vertical arm swing axis S2 (lower arm) is substantially vertical.

Next, the first calibration process is carried out. Specifically, as shown in FIG. 2, the operator operates the teaching pendant to operate the horizontal arm swing shaft S3, the wrist rotation shaft S4, and the wrist swing shaft S5 to set the working point A to the first mark M ₁ By positioning the robot so that it is aimed at, the robot takes the first calibration posture. The positioning of the adjusting tip 7 is visually ± 0.5 mm with respect to the first mark M ₁ .
It is enough if it can be adjusted to the degree. Also, the wrist rotation axis S4 and the wrist swing axis S in the teaching pendant
The forward / reverse keys that operate 5 are these axes S4 and S4.
It is desirable that 5 is disabled during the first calibration process so that it does not operate due to an erroneous operation by the operator.

Next, when the robot takes the first calibration posture, the operator depresses a "memory" switch to instruct the controller 12 to read the detected angles θ _{3 to} θ _5. Become. At this time, as shown in FIG. 4, the detected angles θ _{1 to} θ ₅ are constantly output from the angle detectors 11a to 11e to the controller 12 and are input to a pulse counter (not shown), a current position buffer, etc. Instructed controller 1
The calculation unit 14 of 2 reads the detected angles θ _{3 to} θ ₅ as the current position (angle) from a pulse counter, a current position buffer, or the like corresponding to the horizontal arm swing axis S3, the wrist rotation axis S4, and the wrist swing axis S5. It will be. And the arithmetic unit 1
4 is the reference angle θ from the reference angle storage area 15a of the storage unit 15.
Read out ₃ ^{* to} θ ₅ ^* and set these reference angles θ ₃ ^{* to} θ ₅
The difference between ^* and the detected angles θ _{3 to} θ ₅ is obtained as the correction values Δθ _{3 to} Δθ ₅ (Δθ ₃ = θ ₃ ^* −θ ₃ , Δθ ₄
= Θ ₄ ^* -θ ₄ , Δθ ₅ = θ ₅ ^* -θ ₅ ).

The above correction values Δθ _{3 to} Δθ ₅ are stored in the storage unit 1.
Would be stored in the fifth correction value storage area 15b, the subsequent horizontal arm swinging shaft S3, the angle detection of the wrist rotation shaft S4 and wrist swing shaft S5, the actual detection angle theta ₃ ~
theta becomes ₅ to the correction value Δθ ₃ ~Δθ ₅ corrected detection angle theta ₃ by adding that 'through? _5' are used (θ ₃ '= θ ₃
+ Δθ ₃ , θ ₄ '= θ ₄ + Δθ ₄ , θ ₅ ' = θ ₅ + Δθ
₅ ).

Next, the horizontal arm swing shaft S3, the wrist rotation shaft S4, and the wrist swing shaft S5 are set to a predetermined posture (angle) automatically or by an operator's instruction. By holding the postures of the axes S3 to S5, the second calibration process is executed while the horizontal arm and the subsequent parts are treated as one rigid body. Specifically, as shown in FIG. 3, the operator operates the teaching pendant to actuate the base pivot axis S1 and the vertical arm swing axis S2 to aim and position the working point A at the second mark M ₂ . By
This causes the robot to take the second calibration posture.

The base swing axis S1, the vertical arm swing axis S2, and the horizontal arm swing axis S in the teaching pendant.
The forward / reverse keys that operate 3 are those axes S1 to S
2 so that 3 does not operate due to operator's mistaken operation.
It is desirable that it be disabled during the calibration process.

Next, when the robot takes the second calibration posture, the operator depresses a "memory" switch to instruct the controller 12 to read the detected angles θ ₁ and θ _2. Become. As shown in FIG. 4, the controller 1 instructed to read
2, the detected angles θ ₁ and θ ₂ are read as the current position (angle) from a pulse counter or a current position buffer corresponding to the base turning axis S1 and the vertical arm swing axis S2. Then, these detected angles θ ₁ and θ ₂ and the reference angle θ ₁
The difference between ^* and θ ₂ ^* will be calculated as the correction values Δθ ₁ and Δθ ₂ (Δθ ₁ = θ ₁ ^* −θ ₁ and Δθ ₂ = θ ₂ ^* −
θ ₂ ).

The correction values Δθ ₁ and Δθ ₂ are stored in the correction value storage area 15b of the storage unit 15 described above, and the base turning axis S1 and the vertical arm swing axis S thereafter.
For the angle detection of _{No. 2} , the correction detection angle θ ₁ '・ which is obtained by adding the correction values Δθ ₁ · Δθ ₂ to the actual detection angle θ ₁ · θ ₂
θ ₂ 'will be used (θ ₁ ' = θ ₁ + Δ
θ ₁ , θ ₂ '= θ ₂ + Δθ ₂ ).

In this embodiment, the base turning axis S
It is composed of a vertical multi-joint robot having 5 degrees of freedom, which includes a vertical arm swing axis S2, a vertical arm swing axis S2, a horizontal arm swing axis S3, a wrist rotation axis S4, and a wrist swing axis S5, in this order. There is no such thing. That is, as shown in FIG. 5, a vertical multi-joint robot having 5 degrees of freedom in which the connection order of the wrist rotation axis S4 and the wrist swing axis S5 (θ ₅ ) is exchanged may be used. Correction values Δθ ₃ for the detection angles θ _{3 to} θ ₅ by the first calibration process of FIG.
~ After obtaining Δθ ₅ , the correction value Δθ ₁ · Δθ for the detected angle θ ₁ · θ ₂ is obtained by the second calibration process of FIG. 7.
You can ask for ₂ .

[Embodiment 2] Another embodiment of the present invention will be described with reference to FIGS. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 8, the calibration method according to the present embodiment is an industrial robot comprising a 6-degree-of-freedom vertical articulated robot in which a rotary shaft S6 is provided on the free end side of a wrist swing shaft S5. Will be implemented in. This robot is set so that the working point A of the adjusting tip 7 is located on the central axis of the rotation axis S6.
As shown in FIG. 9, a third mark M ₃ for position alignment is provided on both joints of the rotary shaft S6 and the wrist swing shaft S5.
The third mark M ₃ is formed over S5 and is used in the third calibration process for obtaining the correction value Δθ ₆ of the rotation axis S6. Other configurations are
Same as Example 1.

In the above configuration, when the correction values Δθ _{1 to} Δθ ₆ of the axes S1 to S6 are obtained, the detection angles θ _{3 to} θ are obtained by the first calibration process as in the first embodiment.
_After the correction values Δθ _{3 to} Δθ ₅ for ₅ are obtained, the second
The correction value Δθ ₁ · Δθ ₂ will be required for the detected angle θ ₁ · θ ₂ by the calibration process. After that, the third calibration process is performed, the rotation axis S6 is rotated, and the detection angle θ ₆ when the third mark M ₃ is aligned is read, and the reference angle θ ₆ stored in advance is read. The difference from ^* is obtained as the correction value Δθ ₆ .

[Embodiment 3] Another embodiment of the present invention is shown in FIG.
Will be explained. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 10, the calibration method according to the present embodiment is an industrial robot comprising a 6-degree-of-freedom vertical articulated robot in which a rotary shaft S6 is provided on the free end side of a wrist swing shaft S5. Will be implemented in. In this robot, the working point A is set at a position deviated from the central axis of the rotation axis S6, and one tip portion 13 is set.
A indicates the central axis of the rotation axis S6, and the other tip portion 13b indicates the working point A, and the adjustment tip 13 branched in two directions is attached.

A second mark M ₂ used for positioning one tip portion 13a of the adjusting tip 13 and a second mark M ₂ used for positioning the other tip portion 13b are provided on the fixed portion of the base turning shaft S1. 4 mark M ₄ is formed, and the fourth mark M ₄ is adapted to be used in the fourth calibration process for obtaining the correction value Δθ ₆ of the rotation axis S6. Other configurations are the same as those in the first embodiment.

In the above structure, when the correction values Δθ _{1 to} Δθ ₆ of the respective axes S1 to S6 are obtained, first, the rotation axis S
The adjusting tip 13 is attached to the tip of the tool provided in the tool 6. Then, one tip portion 13a of the adjusting tip 13 is set as a temporary working point B, and using this working point B, correction values for the detection angles θ _{3 to} θ ₅ are obtained by the first calibration process as in the first embodiment. After Δθ _{3 to} Δθ ₅ are obtained, the correction values Δθ ₁ · Δθ ₂ for the detection angles θ ₁ · θ ₂ are obtained by the second calibration process.

After that, the fourth calibration process is carried out, and only one end portion 13a (working point B) of the adjusting tip 13 is aligned with the second mark M ₂ and only the rotating shaft S6 is moved. Will be rotated. And
When the other tip portion 13b (the working point A) is positioned coincident with the third mark M _3, the detection angle theta ₆ is read, prestored difference between the reference angle theta ₆ ^* have the correction value Δ
It will be calculated as θ ₆ .

[Embodiment 4] Another embodiment of the present invention is shown in FIG.
Through FIG. 15 will be described. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 11, the calibration method according to the present embodiment is adapted to be carried out in an industrial robot whose vertical arm has a parallel link mechanism. In this robot, the horizontal arm is swung by a drive motor of a horizontal arm swing shaft S3 coaxial with the vertical arm swing shaft S2 via a parallel link mechanism. The controller 12 has a robot
The reference included angle θ ₂₃ ^* between the vertical arm swing axis S2 and the horizontal arm swing axis S3 when the calibration posture is taken is stored. Other configurations are the same as those in the first embodiment.

In the above configuration, when the correction values Δθ _{1 to} Δθ ₅ of the axes S1 to S5 are obtained, first, the correction values Δ
The first calibration process for obtaining θ _{3 to} Δθ ₅ will be performed. Specifically, as shown in FIG. 12, the horizontal arm swing shaft S3, the wrist rotation shaft S4, and the wrist swing shaft S5 are actuated to position the working point A at the first mark M ₁ , thereby enabling the robot to move. It takes the first calibration posture. Then, when the robot takes the first calibration posture, a pulse counter corresponding to the vertical arm swing axis S2, the horizontal arm swing axis S3, the wrist rotation axis S4, and the wrist swing axis S5 is provided to the controller 12. The detected angles θ _{2 to} θ ₅ are read as the current position (angle) from the current position buffer or the like.

Next, as in the first embodiment, the wrist rotating shaft S4
The correction value Δθ ₄ and the correction value Δθ ₅ of the wrist swing axis S5 are obtained by subtracting the detected angles θ ₄ and θ ₅ from the reference angles θ ₄ ^* and θ ₅ ^* . The correction value Δθ ₃ of the horizontal arm swing axis S3 is obtained as follows because the horizontal arm swing axis S3 swings together with the vertical arm swing axis S2. That is, the included angle θ ₂₃ between the horizontal arm swing axis S3 and the vertical arm swing axis S2 is the angle obtained by subtracting the detected angle θ ₂ of the vertical arm swing axis S2 from the detected angle θ ₃ of the horizontal arm swing axis S3 ( to correspond to θ ₃ -θ _2), the angle (θ ₃ -θ ₂₎ a reference included angle theta ₂₃ ^*
The correction value Δθ ₃ can be obtained by subtracting from (Δθ ₃ = (reference angle of included angle) − (θ ₃ −
θ ₂ )).

Next, a second step for obtaining the correction values Δθ _{3 to} Δθ ₅
The calibration process will be performed. Specifically, as shown in FIG. 13, the wrist rotation axis S4 and the wrist swing axis S5 are set to a predetermined posture, and the included angle θ ₂₃ between the vertical arm swing axis S2 and the horizontal arm swing axis S3. Will be set to a predetermined angle. Then, while the horizontal arm swing axis S3 follows the vertical arm swing axis S2 so that the included included angle θ ₂₃ is kept constant, the base swing axis S1 and the vertical arm swing axis S2 are operated,
When the robot takes the second calibration posture, the correction values Δθ ₁ · Δθ ₂ are obtained in the same manner as in the first embodiment.

In the calibration method of this embodiment, as shown in FIGS. 14 and 15, the wrist swing shaft S5 is provided with the rotary shaft S6, and the working point A is located on the rotary shaft S6. The parallel link type robot can also be used.

[0042]

As described above, according to the present invention, the detected angles of the base pivot axis, the vertical arm pivot axis, the horizontal arm pivot axis, the wrist rotary axis and the wrist pivot axis are respectively corrected based on the reference angle. A calibration method for an industrial robot, comprising a first calibration in which a working point is positioned at a first reference position on a vertical arm by operating the horizontal arm swing shaft, the wrist rotation shaft, and the wrist swing shaft. The horizontal arm swing axis, the wrist rotation axis, and the wrist swing axis are detected in the posture, and the detected angles are corrected based on the reference angles corresponding to these detected angles. By operating the base swing axis and the vertical arm swing axis while maintaining the arm swing axis, wrist rotation axis, and wrist swing axis in a predetermined posture using the corrected detection angles, A second calibration posture is positioned in the second reference position on the base of the fixed part,
Obtaining the detection angles of the base swing axis and the vertical arm swing axis in the posture, and based on the reference angles corresponding to these detection angles,
The configuration is such that each of these detection angles is corrected.

Thus, the working point can be obtained with a standard jig, and the positioning of the working point can be performed by the same operation as the teaching work, so that the correction of the detection angles of all axes can be easily completed. . Further, since the first reference position and the second reference position used for correction are set on the vertical arm of the industrial robot and the fixed portion of the base, respectively, even if the industrial robot is relocated, The positional relationship between the reference position and the second reference position is always constant, and there is an effect that an error does not occur in the correction.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a state of each axis of an industrial robot.

FIG. 2 is an explanatory diagram showing a state of each axis of the industrial robot in the first calibration posture.

FIG. 3 is an explanatory diagram showing a state of each axis of the industrial robot in a second calibration posture.

FIG. 4 is a block diagram of a controller.

FIG. 5 is an explanatory diagram showing a state of each axis of the industrial robot.

FIG. 6 is an explanatory diagram showing a state of each axis of the industrial robot in the first calibration posture.

FIG. 7 is an explanatory diagram showing a state of each axis of the industrial robot in the second calibration posture.

FIG. 8 is an explanatory diagram showing a state of each axis of the industrial robot.

FIG. 9 is an explanatory diagram showing a state of a third mark.

FIG. 10 is an explanatory diagram showing a state of each axis of the industrial robot.

FIG. 11 is an explanatory diagram showing a state of each axis of the industrial robot.

FIG. 12 is an explanatory diagram showing a state of each axis of the industrial robot in the first calibration posture.

FIG. 13 is an explanatory diagram showing a state of each axis of the industrial robot in the second calibration posture.

FIG. 14 is an explanatory diagram showing a state of each axis of the industrial robot in the first calibration posture.

FIG. 15 is an explanatory diagram showing a state of each axis of the industrial robot in the second calibration posture.

[Explanation of symbols]

S1 Base rotation axis S2 Vertical arm swing axis S3 Horizontal arm swing axis S4 Wrist rotation axis S5 Wrist swing axis S6 Rotation axis 7 Adjustment tip M ₁ 1st mark M ₂ 2nd mark M ₃ 3rd mark M _4th 4 marks 10a to 10e Drive motors 11a to 11e Angle detector 12 Controller 13 Adjustment chip

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuji Minato Nakahara 1-2, Sanya-cho, Toyohashi-shi, Aichi 2 Kobe Steel, Ltd. Toyohashi FA / Robot Center

Claims (1)

[Claims] 1. A calibration method for an industrial robot, which corrects detected angles of a base pivot axis, a vertical arm pivot axis, a horizontal arm pivot axis, a wrist rotary axis, and a wrist pivot axis based on a reference angle. By operating the horizontal arm swing shaft, the wrist rotation shaft and the wrist swing shaft, the working point is moved to the first position on the vertical arm.
With the first calibration posture positioned at the reference position, the detected angles of the horizontal arm swing axis, the wrist rotation axis, and the wrist swing axis in the posture are obtained, and based on the reference angles corresponding to these detected angles, these are determined. Correcting the detection angles respectively, while maintaining the horizontal arm swing axis, wrist rotation axis and wrist swing axis in a predetermined posture using the corrected detection angles,
By operating the base turning axis and the vertical arm swinging axis, the working point is set to the second reference position on the fixed portion of the base, and the base turning axis and the vertical arm swinging at the second calibration attitude are set. A method for calibrating an industrial robot, which comprises detecting detected angles of a moving axis and correcting these detected angles based on reference angles corresponding to the detected angles.