JP3388016B2 - Calibration method for horizontal articulated robot - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of calibrating a horizontal articulated robot, and more particularly, to a method of calibrating an arm of a horizontal articulated robot such as an industrial robot having a mechanism for changing the posture of a hand. In particular, it is possible to calibrate the arm length and joint origin position while preventing the influence of the error of the mechanism that changes the posture of the hand, and to obtain absolute position accuracy at least within the teaching point range used for calibration. The present invention relates to a calibration method for a horizontal articulated robot that can be improved.

[0002]

2. Description of the Related Art Conventionally, in a horizontal articulated robot of a type in which two arms rotate and move in the horizontal direction, it is necessary to calibrate the arm length and the joint origin position in order to improve the absolute position accuracy. As an easy method for calibrating the arm length and the joint origin position, some teaching methods have been considered. Regarding this teaching method, a method by teaching three points arranged at equal intervals on a straight line,
A method by teaching four points to form a rectangle, 1
A method of teaching points by changing the hand system is known. In addition, about is reported in, for example, Journal of Precision Machinery, Volume 49, No. 9, reprint, "Calibration by Teaching SCARA Robot Specifications", Nobuyuki Furuya, Hiroshi Makino (published on September 5, 1983). This is also reported in, for example, JP-A-1-127283.

[0003]

However, in the conventional horizontal articulated robot as described above, when calibrating the robot in which each joint is tilted due to an assembly error or the like, the arm is applied by the above methods (1) to (3). When calibration is performed, an error occurs in the arm length and the joint origin position, and the absolute position accuracy cannot be guaranteed. In particular, in a conventional horizontal articulated robot having a mechanism for changing the posture of the hand, as shown in FIG. 13, the rotation center of the J3 shaft 101 and the hand are displaced, or the J3 shaft 101 is tilted. In such a case, if the calibration is performed by the above method as it is, the distance R between the axis 102 of J1 and the axis 103 of J2 is
1, the distance R2, J between the axis 103 of J2 and the axis 101 of J3
Since the 1st axis 102 and the J2 axis 103 include the error, accurate calibration cannot be performed and absolute position accuracy cannot be guaranteed. For this reason, when a plurality of robots share a work area, the coordinate systems are misaligned and a common coordinate system cannot be set, which may make offline teaching difficult.

Therefore, according to the present invention, when changing the posture of the hand in which each joint is tilted due to an assembly error or the like, without using a complicated model such as a three-dimensional model,
A simple method of teaching three points arranged at a right angle with the posture fixed and teaching one of the points by changing the posture prevents the influence of the error of the mechanism for changing the posture of the hand and prevents the arm length. It is an object of the present invention to provide a horizontal articulated robot calibration method capable of calibrating the joint origin position and improving the absolute position accuracy at least within the range of teaching points used for the calibration.

[0005]

The invention according to claim 1 is
In a calibration method for a horizontal articulated robot having a mechanism for changing the posture of the hand, the posture of the hand is fixed to three coordinate points arranged at right angles and having known intervals with respect to a coordinate system obtained by forward kinematics. It is characterized by teaching and teaching one of the points by changing the posture of the hand.

According to a second aspect of the present invention, in the above-mentioned first aspect of the invention, the calibration is performed by teaching three points which are taught by fixing the posture of the hand in common to each of a plurality of robots sharing a work area. It is characterized by performing. The invention according to claim 3 is the same as the invention according to claim 1,
It is characterized in that a calibration hand attached to the robot is fitted to a calibration jig fixed within the operation range of the robot, and the posture of the hand is fixed by the shape of the calibration hand.

According to a fourth aspect of the present invention, in the above-mentioned third aspect, a force torque sensor is arranged on the calibration jig or the calibration hand to detect the deviation of the teaching position. It is what According to a fifth aspect of the present invention, in the above-mentioned first aspect of the invention, a calibration jig fixed to an operating range of the robot is provided with a light source or a sensor for detecting light from the light source, and the calibration is attached to the robot. It is characterized in that the other hand is placed on the hand to fix the posture of the hand without contact.

According to a sixth aspect of the present invention, in the above-mentioned fifth aspect, the posture of the hand is fixed by the arrangement state of the light source or the sensor in which the calibration jig and the calibration hand are arranged. It is what The invention according to claim 7 is the same as the invention according to claim 5,
At least two light sources having different colors and a color sensor for detecting the light color of the light source are arranged on the calibration jig and the calibration hand, and the posture of the hand is fixed depending on the arrangement state of the light source. It is what

According to an eighth aspect of the invention, in the invention of the fifth aspect, the posture of the hand is arranged by disposing at least one set of the light source and the sensor in each of the calibration jig and the calibration hand. It is characterized by fixing. The invention according to claim 9 is the above claim 4, 5
In the described invention, the lamp is turned on when the output of the sensor exceeds a certain amount.

The invention according to claim 10 is the above-mentioned claim 4,
In the invention described in 5, a sound is emitted when the output of the sensor exceeds a certain amount. According to an eleventh aspect of the present invention, in the above-mentioned third and fifth aspects of the present invention, the calibration jig is fixed within the operation range of the robot by disposing an auto tool changer on the calibration jig. It is a feature.

The invention according to claim 12 is the above-mentioned claim 3,
In the invention described in 5, the height of the calibration jig is made variable so that the calibration is performed according to the height of the working position. The invention according to claim 13 is
In the invention described in claims 2, 3 and 5, the workbench is provided with the function of the calibration jig.

The invention according to claim 14 is the above-mentioned claim 2,
In the invention described in claims 3 and 5, the component supply pallet is provided with the function of the calibration jig.

[0013]

According to the first aspect of the present invention, a complex model such as a three-dimensional model is used in a horizontal articulated robot having a mechanism for changing the posture of the hand in which each joint is tilted due to an assembly error or the like. Without changing the posture of the hand, one of them is taught by fixing the posture of the hand with respect to the coordinate system obtained by forward kinematics without changing the posture of the hand. By performing the simple teaching method, it is possible to calibrate the arm length and the joint origin position while preventing the influence of the error of the mechanism for changing the posture of the hand. Moreover, by teaching three points at right angles, at least within the range of the teaching points used for calibration,
It is possible to improve absolute position accuracy such as linearity and length.

According to a second aspect of the present invention, in a plurality of robots sharing a work area, common three points in the shared work area are taught by fixing the posture of the hand to each robot to perform calibration. This allows a plurality of robots to work in a common coordinate system. For example, by teaching and calibrating three common points on the workbench in the work area shared by the two robots, linear interpolation on the workbench can be performed in a common coordinate system. If calibration is performed on the component supply pallet, palletizing can be performed using a common coordinate system.

According to the third aspect of the invention, the teaching pin of the calibration hand attached to the robot is fitted to the teaching of the calibration jig fixed within the operation range of the robot.
Accurate teaching can be performed by finishing the positions of the teaching pin of the calibration hand and the teaching hole of the calibration jig with high accuracy. In this teaching method, as a method of fixing the posture of the hand with respect to the coordinate system obtained by the forward kinematics in the shape of the calibration hand, two pins (cylinder), a long cylinder, a rectangular parallelepiped, and a triangular prism other than a regular triangular prism are used. Etc. In any case, it has a shape for fitting it to a calibration jig, and can fix the posture in a fixed direction. Of these,
The methods of, and can make the direction of the posture constant, but cannot determine the direction.

However, in this case, it is sufficient that the teacher sees the rotation of the hand so as not to change the direction. The method can determine both the direction and orientation according to its shape, and the posture can be fixed with respect to the coordinate system obtained by forward kinematics, as well as polygonal prisms other than regular polygonal cylinders and the vertices of the polygons. The posture can be fixed even with a hand that raises a pin.

According to the present invention, by disposing the force torque sensor on the calibration jig or the calibration hand, it is possible to detect the deviation of the teaching position and notify the operator, so that the accuracy is high. Can be taught.
For example, by installing a force torque sensor between the auto hand changer of the calibration hand and the remote center compliance, or between the calibration plate of the calibration jig and the auto tool changer, distortion of the calibration hand and calibration jig By detecting the distortion, the operator can be notified of the deviation of the teaching position.

According to a fifth aspect of the present invention, a plurality of light sources or sensors for detecting light are arranged on a calibration jig fixed in the operation range of the robot, and the other is arranged on a calibration hand attached to the robot. By doing so, the teaching can be performed in a non-contact manner, so that the teaching can be performed with higher accuracy. In the invention according to claim 6, as a method of fixing the posture of the hand with respect to the coordinate system obtained by forward kinematics, at least three light sources or optical sensors are arranged in the calibration hand and the calibration jig. It is possible to determine both the direction and the direction depending on the arrangement shape.

According to a seventh aspect of the present invention, as a method of fixing the posture of the hand with respect to the coordinate system obtained by forward kinematics, at least two or more light sources different in color and a color sensor for detecting the color are provided. By disposing it on the calibration jig and the calibration hand, the direction can be fixed by disposing the two light sources, and the direction can be fixed by the color.

According to the eighth aspect of the present invention, as a method for fixing the posture of the hand with respect to the coordinate system obtained by forward kinematics, at least one set of light source and sensor is arranged on each of the calibration jig and the calibration hand. By doing so, the posture can be uniquely fixed. According to the invention of claim 9, when the output of the sensor exceeds a certain amount, the sensor output determination unit and the function of turning on the lamp are provided so that the operator can visually confirm that the teaching position is correct. I can inform you.

According to the tenth aspect of the present invention, when the output of the sensor exceeds a certain amount, the sensor output determination unit and the function of producing a sound are provided to make sure that the teaching position is audibly correct. Can inform the person. According to the eleventh aspect of the present invention, by disposing the auto tool changer on the calibration jig, the calibration jig can be easily and accurately fixed within the operation range of the robot.

According to the twelfth aspect of the present invention, the height of the calibration jig is made variable so that the calibration can be performed in accordance with the height of the work position of the work table, the component supply pallet, etc. Since it is possible to suppress the influence of the flexure, it is possible to calibrate the work position with high accuracy. In a thirteenth aspect of the invention, the workbench is provided with the function of the calibration jig, that is, the workbench is provided with a teaching hole for a teaching method or a light source or a sensor for a non-contact teaching method. By doing so, it is possible to eliminate the effects of assembly errors and positioning errors of the calibration jig and perform high-accuracy calibration on the workbench, so linear interpolation on the workbench can be performed with high accuracy, and horizontal work can be performed. It can be performed.

In the fourteenth aspect of the present invention, the component supply pallet is provided with the function of the calibration jig, that is, the component supply pallet is a teaching hole of a teaching method by fitting or a non-contact teaching method. By providing the light source or sensor of the above, it is possible to remove the influence of the assembly error and the positioning error of the calibration jig and perform the calibration with high accuracy on the pallet, and thus to obtain the highly accurate palletizing coordinates on the pallet. You can

[0024]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a diagram showing a joint arrangement of a horizontal articulated robot according to an embodiment of the present invention, and FIG. 2 is a diagram showing a calibration method of the horizontal articulated robot shown in FIG. First, a method of calibrating a horizontal articulated robot having the mechanism shown in FIG. 1 will be described with reference to FIG. Spaced at right angles (LX, L
Y) is known, and three points P1, P2, P3 are taught by fixing the posture of the hand with respect to the coordinate system obtained by forward kinematics, and the rotation angles of J1, J2, J3 from the joint origin at that time. (Θa1, θb1, θc1), (θa2, θb2, θb2), (θ
a3, θb3, θc3). Further, J3 is rotated by an arbitrary angle to teach the same point P4 as P1, and the rotation angle at that time is (θa4, θb4, θc4).
Misalignment between the rotation center of the arm lengths R1, R2, J3 and the position of the hand R3, J1, J2, J3 joint origin positions θa0, θb0
Calibrate θc0. The unknown quantity of the vector equation obtained from this relationship is the components X1 and Y1 of P1 (X1, Y1),
Joint origin positions θa0, θb0, θC0, first and second arm lengths R1 and R2, the center of rotation of J3, and the shift of the hand position R
It is 3. The obtained vector equation is the following equation (1)
It can be expressed by equation (4).

[0025]

[Equation 1]

[0026]

[Equation 2]

[0027]

[Equation 3]

[0028]

[Equation 4]

Here, regarding P1, P2, and P3, since the posture of the hand is fixed with respect to the coordinate system obtained by forward kinematics, when the posture of the hand is θ, θ is It can be expressed by equation (5).

[0030]

[Equation 5]

Therefore, P1 (X1, Y1), P2 (X1
+ LX, Y1) and P3 (X1, Y1 + LY) can be expressed by the following equations (6) to (8).

[0032]

[Equation 6]

[0033]

[Equation 7]

[0034]

[Equation 8]

From these, P2-P1 and P3-P1
Can be expressed by the following equations (9) and (10).

[0036]

[Equation 9]

[0037]

[Equation 10]

Here, exp (jθa2) -exp (jθ
a1), exp (j (θa2 + θb2))-exp (j (θa1
+ Θb1)), exp (jθa3) -exp (jθa1) and exp (j (θa3 + θb3))-exp (j (θa1 + θb
1)) as shown in the following equations (11) to (14),

[0039]

[Equation 11]

[0040]

[Equation 12]

[0041]

[Equation 13]

[0042]

[Equation 14]

In other words, the above equations (9) and (10) can be expressed by the following equations (15) and (16).

[0044]

[Equation 15]

[0045]

[Equation 16]

From the expressions (15) and (16), exp (j
If θa0) is deleted, it can be expressed by the following equation (17).

[0047]

[Equation 17]

When exp (jθb0) is rearranged from the expression (17), it can be expressed by the following expression (18).

[0049]

[Equation 18]

Here, LYk1exp (j (θ1 + π /
2))-LXK3exp (jθ3) and LXK4exp (j
θ4) -LYK2exp (j (θ2 + π / 2)) is expressed by the following equations (19) and (20).

[0051]

[Formula 19]

[0052]

[Equation 20]

Then, it can be expressed by the following equation (21).

[0054]

[Equation 21]

By solving the equation (21), R2 and θb0 can be expressed by the following equations (22) and (23).

[0056]

[Equation 22]

[0057]

[Equation 23]

By substituting the equation (22) into the above equation (15), it can be expressed by the following equation (24).

[0059]

[Equation 24]

Here, K7exp (jθ7) is converted into the following (2
As shown in equation 5),

[0061]

[Equation 25]

In other words, LX can be expressed by the following equation (26).

[0063]

[Equation 26]

By solving the equation (26), R1 and θa0 are given by the following equations (27) and (28).

[0065]

[Equation 27]

[0066]

[Equation 28]

It becomes Then, (22) and (2
3), (27) and (28), R1, R2, θa0,
θb0 can be obtained. Since P1 and P4 are the same point, they can be expressed by the following equation (29) from the above equations (1) and (2).

[0068]

[Equation 29]

Organizing this equation (29), the following (3
It can be represented by the formula 0).

[0070]

[Equation 30]

Where exp (j (θa0 + θa4))-e
xp (j (θa0 + θa1)), exp (j (θa0 + θa4 +
θb0 + θb4))-exp (j (θa0 + θa1 + θb0 + θb
1)) and exp (j (θa0 + θa1 + θb0 + θb1 + θc
1))-exp (j (θa0 + θa4 + θb0 + θb4 + θc
4)) as shown in the following equations (31) to (33),

[0072]

[Equation 31]

[0073]

[Equation 32]

[0074]

[Expression 33]

If this is put, it can be expressed by the following equation (34).

[0076]

[Equation 34]

Further, R1K8exp (jθ8) + R2K9e
xp (jθ9) is given by the following equation (35):

[0078]

[Equation 35]

Then, it can be expressed by the following equation (36).

[0080]

[Equation 36]

By solving the equation (36), R3 and θc0 can be expressed by the following equations (37) and (38).

[0082]

[Equation 37]

[0083]

[Equation 38]

From these equations (37) and (38), R3, θ
c0 can be obtained. As described above, according to the present embodiment (claim 1), in a horizontal articulated robot having a mechanism for changing the posture of the hand in which each joint is tilted due to an assembly error or the like, a complicated three-dimensional model or the like is used. Without using a model, three points with known intervals arranged at right angles are taught by fixing the posture of the hand with respect to the coordinate system obtained by forward kinematics, and one of them is the posture of the hand. By performing the simple method of changing and teaching, the influence of the error (R3, θc0) of the mechanism for changing the posture of the hand is prevented and the arm length and the joint origin position R1, R2, θa.
It is possible to calibrate 0 and θb0, and to know R3 and θc0. Further, by teaching three points at a right angle, it is possible to improve absolute position accuracy such as squareness, linearity, length, etc. at least within the range of teaching points used for calibration.

Next, in a plurality of robots sharing a work area as shown in FIG. 3, three common points in the work area to be shared are taught to each robot while the posture of the hand is fixed, and It may be configured to calibrate by the method of the embodiment, in which case a plurality of robots can work in a common coordinate system. For example, three common points on the workbench 22 in the shared work area are the robot 1 and the robot 2.
In addition, by fixing the posture of the hand and teaching and calibrating the postures, linear interpolation on the workbench 22 can be performed in a common coordinate system, and calibration can be performed on the component supply pallet 23. , It is possible to palletize in a common coordinate system.

Next, as a teaching method, a method of fitting a calibration hand attached to the robot to a calibration jig fixed in the operation range of the robot, a calibration jig fixed in the operation range of the robot There are two methods of teaching in a non-contact manner by having a plurality of light sources or sensors for detecting light and a calibration hand attached to the robot having the other. The former method is, for example, a method of fitting the two teaching pins 4 of the calibration hand 3 shown in FIG. 4 into the teaching holes 6 of the calibration jig 5 shown in FIG. The positions of the teaching pin 4 of the calibration hand 3 and the teaching hole 6 of the calibration jig 5 are finished with high accuracy. Thereby, accurate teaching can be performed. In addition, in FIGS.
Reference numeral 7 is an automatic hand changer, 8 is a cushion, 9 is a remote center compliance, 10 is a calibration plate, and 11 is an automatic tool changer (AHC).
The calibration hand 3 here is provided with a cushion 8 and a remote center compliance 9 function.
Therefore, teaching can be performed by pressing the calibration hand 3 against the calibration plate 10, and fitting can be performed when the teaching position is at an accurate teaching position.

In this teaching method, as a method of fixing the posture of the hand with respect to the coordinate system obtained by forward kinematics, there is a method of fixing the posture by the shape of the calibration hand 3.
For example, as shown in FIGS. 6 to 9, the shape of the calibration hand 3 includes (1) two pins (cylinders), (2) a long cylinder,
Examples include (3) rectangular parallelepiped and (4) triangular prisms other than regular triangular prisms. In any case, it has a shape that fits it to the calibration jig 5, and the posture can be fixed in a fixed direction.

In (1), (2), and (3), the orientation direction can be fixed, but the orientation cannot be determined. However, in this case, the teacher may teach the hand rotation so that the direction does not change.
In (4), both the direction and the orientation can be determined by its shape, and the posture can be fixed with respect to the coordinate system obtained by forward kinematics. The posture can be fixed even with a hand with a pin at the top.

Next, the calibration jig 5 or the calibration hand 3 may be provided with a force torque sensor. In this case, the deviation of the teaching position can be detected and notified to the operator. It is possible to teach with high accuracy. For example, between the automatic hand changer 7 and the remote center compliance 9 of the calibration hand 3 shown in FIG.
By providing a force torque sensor between the calibration plate 10 and the auto tool changer 11 of the calibration jig 5 shown in FIG. The shift can be notified to the operator.

Next, as described above, the calibration jig 5 of FIG. 4 fixed within the operation range of the robot is provided with a light source or an optical sensor instead of the teaching pin 4 of FIG. The calibration hand 3 shown in FIG. 5 may be configured to have the other instead of the teaching hole 6 shown in FIG. 5. In this case, since the teaching can be performed in a non-contact manner, more accurate teaching is possible. It can be performed. In this teaching method, as a method of fixing the posture of the hand with respect to a coordinate system obtained by forward kinematics, for example, (a) at least three light sources and sensors are provided in a calibration jig and a calibration hand,
(B) At least two light sources of different colors and color sensors are provided on the calibration jig and calibration hand. (C) At least one set of light source and sensor is calibrated. The method provided in each of the jig for calibration and the hand for calibration can be mentioned.

Next, as described in (a) above, the calibration hand 3 and the calibration jig 5 are provided with at least three light sources or optical sensors at the apexes of the polygon,
Depending on the arrangement shape, the posture of the hand may be fixed, and in this case, both the direction and the direction can be determined, and the posture can be fixed with respect to the coordinate system obtained by forward kinematics. . For example, the posture can be fixed by disposing three light sources and sensors so as not to form an equilateral triangle, and equipping the calibration hand and the calibration jig so as to match each other.

Next, as shown in (b) above, for example, as shown in FIG.
As shown in 0, at least two or more light sources having different colors, for example, a red light source 12 and a green light source 13, and a color sensor for detecting the color, for example, a red sensor 14 and a green sensor 15, are attached to the calibration jig 5 and the calibration. The hand 3 may be provided, and in this case, the direction can be fixed by arranging two light sources, and the direction can be fixed.

Next, as shown in (c) above, for example, as shown in FIG.
As shown in FIG. 1, a set of the light source 16 and the optical sensor 17 may be provided in each of the calibration hand 3 and the calibration jig 5, and in this case, the posture can be uniquely fixed. Next, when the output of the force torque sensor and the optical sensor exceeds a certain amount, the sensor output determination unit and the lamp may be configured to have a function of lighting, and in this case, visually. The operator can be notified that the teaching position is correct.

Further, when the outputs of the above-described force torque sensor and optical sensor exceed a certain amount, the sensor output determination unit and the function of producing a sound may be provided. The operator can be notified that the teaching position is correct. Next, as shown in FIG. 12, the calibration jig 5 may be provided with an auto tool changer 7 including an auto tool changer tool plate 7a and an auto tool changer master plate 7b. In this case, It is possible to fix the calibration jig 5 easily and highly accurately within the operation range of the robot. In FIG. 12, 18 to 21 are a Z-axis moving table, a ball screw, a coupling, and a motor, respectively. Also,
As shown in FIG. 12, the height of the calibration jig 5 may be variable by the Z-axis moving table 18 connected to the ball screw 19 via the coupling 20 and the motor 21, and In this case, by performing calibration in accordance with the height of the work position such as the workbench or the component supply pallet, the influence of bending in the Z direction can be suppressed, and the work position can be highly accurately calibrated.

Next, the workbench is provided with the function of the calibration jig 5, that is, the teaching hole of the teaching method by fitting the workbench 22 of FIG. 3 or the light source or sensor of the non-contact teaching method. May be configured to have,
In this case, the influence of the assembly error and the positioning error of the calibration jig 5 can be removed and the calibration can be performed on the workbench 22 with high accuracy. Therefore, the linear interpolation on the workbench 22 can be performed with high accuracy. Yes, you can do horizontal work. Further, the component supply pallet is provided with the function of the calibration jig 5, that is, the component supply pallet 23 of FIG. 3, for example, is provided with a teaching hole of a teaching method by fitting, or a light source of a non-contact teaching method. It may be configured to have a sensor. In this case, it is possible to eliminate the influence of the assembly error and the positioning error of the calibration jig 5 and perform the calibration with high accuracy on the component supply pallet 23. Supply pallet 2
It is possible to obtain highly accurate palletizing coordinates on 3.

[0096]

According to the present invention, when the postures of the hands in which the respective joints are tilted due to an assembly error or the like are changed, they are arranged at right angles without using a complicated model such as a three-dimensional model. By performing a simple method of teaching a point with a fixed posture and changing one of the points to teach the posture, the influence of the error of the mechanism for changing the posture of the hand is prevented and the arm length and joint There is an effect that the origin position can be calibrated and the absolute position accuracy can be improved at least within the range of the teaching point used for the calibration.

[Brief description of drawings]

FIG. 1 is a diagram showing a joint arrangement of a horizontal articulated robot according to an embodiment of the present invention.

FIG. 2 is a diagram showing a calibration method of the horizontal articulated robot shown in FIG.

FIG. 3 is a diagram showing a plurality of robots sharing a work area with a component supply pallet applicable to the present invention.

FIG. 4 is a diagram showing a calibration hand having two teaching pins applicable to the present invention.

FIG. 5 is a view showing a calibration jig having a teaching hole applicable to the present invention.

FIG. 6 is a diagram showing a shape of a calibration hand applicable to the present invention.

FIG. 7 is a diagram showing the shape of a calibration hand applicable to the present invention.

FIG. 8 is a diagram showing a shape of a calibration hand applicable to the present invention.

FIG. 9 is a diagram showing a shape of a calibration hand applicable to the present invention.

FIG. 10 is a view of a calibration hand that can be applied to the present invention.
It is a figure which shows the color sensor which detects the light source of each different color and the color of the light source provided in the calibration jig.

FIG. 11 is a diagram showing a set of a light source and an optical sensor provided in each of a calibration hand and a calibration jig applicable to the present invention.

FIG. 12 is a diagram showing an auto tool changer provided in a calibration jig applicable to the present invention and a height varying mechanism of the calibration jig provided in the calibration jig.

FIG. 13 is a diagram showing a joint arrangement of a horizontal articulated robot.

[Explanation of symbols]

1, 2 robot 3 Calibration hand 4 Teaching pin 5 Calibration jig 6 teaching holes 7 Auto hand changer 7a Auto Tool Changer Tool Plate 7b Auto Tool Changer Master Plate 8 cushions 9 Remote Center Compliance 10 Calibration plate 11 Auto Tool Changer 12 Red light source 13 Green light source 14 Red sensor 15 Green sensor 16 light sources 17 Optical sensor 18 Z axis movement table 19 Ball screw 20 Coupling 21 motor 22 Workbench 23 Parts supply pallet

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B25J 3/00-3/04 B25J 9/10-9/22 B25J 13/00-13/08 B25J 19 / 02-19/06 G05B 19/18-19/46

Claims (14)

(57) [Claims] 1. In a calibration method for a horizontal articulated robot having a mechanism for changing the posture of a hand, three points arranged at right angles and having known intervals are set in a coordinate system obtained by forward kinematics. Teaching with fixed posture, 1 of them
A method for calibrating a horizontal articulated robot, characterized by teaching points by changing the posture of a hand. 2. The horizontal multi-joint type according to claim 1, wherein three points for teaching with a fixed hand posture are commonly taught to each of a plurality of robots sharing a work area. Robot calibration method. 3. A calibration hand fixed to the robot is fitted into a calibration jig fixed within the operating range of the robot, and the posture of the hand is fixed by the shape of the calibration hand. 1. A method for calibrating a horizontal articulated robot according to 1. 4. A method for calibrating a horizontal articulated robot according to claim 3, wherein a displacement of the teaching position is detected by disposing a force torque sensor on the calibration jig or the calibration hand. . 5. A non-contact by arranging a light source or a sensor for detecting the light of the light source on a calibration jig fixed within the operation range of the robot and arranging the other on a calibration hand attached to the robot. The method for calibrating a horizontal articulated robot according to claim 1, wherein the posture of the hand is fixed with. 6. The method of calibrating a horizontal articulated robot according to claim 5, wherein the posture of the hand is fixed by the arrangement state of the light source or the sensor on which the calibration jig and the calibration hand are arranged. . 7. At least two light sources of different colors and a color sensor for detecting the light color of the light source are arranged on the calibration jig and the calibration hand, and the posture of the hand is determined by the arrangement state of the light source. The method for calibrating a horizontal articulated robot according to claim 5, characterized in that the robot is fixed. 8. The horizontal multi-arm according to claim 5, wherein the posture of the hand is fixed by disposing at least one set of the light source and the sensor in each of the calibration jig and the calibration hand. Calibration method for an articulated robot. 9. The method for calibrating a horizontal articulated robot according to claim 4, wherein a lamp is turned on when the output of the sensor exceeds a certain amount. 10. The method for calibrating a horizontal articulated robot according to claim 4, wherein a sound is emitted when the output of the sensor exceeds a certain amount. 11. The horizontal multi-joint type according to claim 3, wherein the calibration jig is fixed within the operation range of the robot by disposing an auto tool changer on the calibration jig. Robot calibration method. 12. A method for calibrating a horizontal articulated robot according to claim 3, wherein calibration is performed according to the height of the work position by varying the height of the calibration jig. . 13. The method for calibrating a horizontal articulated robot according to claim 2, wherein the workbench is provided with the function of the calibrating jig. 14. The method for calibrating a horizontal articulated robot according to claim 2, wherein the component supply pallet has the function of the calibration jig.