JP2007054906A - Articulated robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an articulated robot, operated without drawing a moving locus with a large curve even when a certain teaching position is away from the next teaching position. <P>SOLUTION: This articulated robot includes: a position calculating means 99 for calculating the position of an output end 32 by coordinates of a rectangular coordinate system; a first storage means 69 for storing the coordinates of the rectangular coordinate system of the teaching position of the output end 32 at the time of teaching operation; a dividing position calculating means 73 for dividing the distance between the teaching positions into predetermined intervals, and calculating the position of each dividing point of divided intervals by the coordinates of the rectangular coordinate system; a second storage means 69 for storing the coordinates of the dividing points calculated by the dividing position calculating means 73; and a movement control means 74 for controlling the output end 32 to move through the dividing points calculated by the dividing position calculating means 73 between the teaching positions in moving the output end 32. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an articulated robot that automatically performs various operations by moving an output side end located at the tip of a plurality of connected arm portions to a predetermined position (teaching position).

An articulated robot is installed in a factory or the like, and a work tool or work piece provided at an output side end located at the tip of a plurality of connected arm parts moves to a predetermined position, It automatically performs operations such as grinding, polishing, and assembly.
In such an articulated robot, teaching (teaching) for storing the movement locus of the output side end of the articulated robot in advance is performed in order to automatically execute the machining operation of the articulated robot. It is.

The teaching is that the operator holds the arm part of the articulated robot by hand or moves the arm part to a predetermined position by operating the operating means for automatically operating the arm part. The information on the moved position is stored in the storage means.
However, the information on the position here is information on the rotational position of the servo motor provided in the arm portion of the articulated robot.

Hereinafter, the configuration and operation of the articulated robot will be described with reference to FIGS.
The articulated robot 10 shown here is provided with a first servomotor 11 at one end, a first arm 12 part rotatably provided by the first servomotor 11, and the first arm part 12. A second servo motor 14 provided at the other end of the first servo motor 14 and a second arm motor 16 connected to the one end of the second servo motor 14 so as to be rotatable with respect to the first arm unit 12. Have.

The other end of the second arm portion 16 is an output side end portion 18 on which a workpiece or a tool is provided.
When the output side end 18 is moved from position 1 to position 2, the second servo motor 14 is rotated counterclockwise by the angle α (FIG. 20).
Then, as the position information of position 2, the counterclockwise rotation angle α of the second servomotor 14 is stored in the storage means.

Further, when the output side end 18 is moved from position 2 to position 3, the first servo motor 11 is rotated counterclockwise by an angle β and the second servo motor 14 is rotated clockwise by an angle γ. (Fig. 21).
Then, as the position information of position 3, the counterclockwise rotation angle β of the first servomotor and the clockwise rotation angle γ of the second servomotor are stored in the storage means.

Note that there may be a need to correct the taught position even after teaching.
However, as described above, the operator can confirm the teaching position only by the information related to the rotation angle (α, β, γ, etc.) of the servo motor, and therefore, for example, the teaching position is moved forward by 1 mm when viewed from the operator. Thus, correction based on the coordinate system viewed from the operator is difficult.

Therefore, in an articulated robot that operates in a horizontal plane, a configuration has been realized in which position data in an orthogonal coordinate system and position data in a polar coordinate system (joint coordinate system) are converted to each other for teaching ( For example, refer to Patent Document 1, Patent Document 2, and Patent Document 3.)
According to such a configuration, the teaching operation can be performed based on the coordinates displayed in an orthogonal coordinate system that is easy for the operator to understand, which is very convenient when grasping and correcting the teaching position.

JP-A-9-85656 (paragraph 0007, etc.) JP-A-9-160618 (Claim 1 etc.) JP-A-6-134655 (paragraph 0007, etc.)

As mentioned in the prior art, even if the position data simply expressed in Cartesian coordinates can be converted into polar coordinates (joint coordinates) according to the driving of the articulated robot, Therefore, it is difficult to accurately perform a linear motion along the coordinate axes of the orthogonal coordinate system.
That is, as shown in FIG. 22, when the distance between the position designated at the time of teaching and the position designated next is large, the movement trajectory of the articulated robot may move along a large curve. There existed a subject that the output side edge part of a joint type robot might contact the location which was not assumed.
Also, if the movement trajectory of the articulated robot becomes a large curve, the movement distance from the teaching position to the next teaching position will increase accordingly, and the operation of the articulated robot may take too much time. There was also a problem that there was.

  Accordingly, the present invention has been made to solve the above-described problems. The object of the present invention is to control an orthogonal coordinate system from the viewpoint of an operator when teaching an articulated robot, An object of the present invention is to provide an articulated robot that operates without drawing a large curved movement locus even when the teaching position is separated.

  According to the articulated robot according to the present invention, a plurality of arm portions whose base portions are connected to the tip portion of the base portion or the adjacent arm portion so as to be rotatable in the same plane or in a parallel plane, and the arm In a multi-joint type robot having a driving means for rotationally driving a part in the plane, a position for calculating a position of an output side end provided at a tip by coordinates in an orthogonal coordinate system including the plane in a coordinate plane Calculating means; and first storage means for storing coordinates in the orthogonal coordinate system of the output side end at any of a plurality of teaching positions on a movement locus of the output side end during a teaching operation; The distance between the teaching positions is calculated based on the coordinates stored in the first storage means in the order determined in the teaching operation, the distance is divided at predetermined intervals, and the divided divisions are calculated. Point position, coordinate the plane Division position calculation means for calculating by coordinates in an orthogonal coordinate system included in the surface; second storage means for storing the coordinates of the division points calculated by the division position calculation means; and the plurality of determined teaching positions When the output side end is moved, the driving means moves the division point calculated by the division position calculation means via the output side end between the teaching position and the teaching position. And a movement control means for controlling the rotation of the motor.

The effect | action by employ | adopting this structure is as follows.
The operator determines the current position of the output side end as the teaching position while moving the output side end during the teaching operation. When the teaching position is determined, first, the division position calculation means further divides the origin and the teaching position from the origin to the first teaching position, and calculates the coordinates of these division points in the orthogonal coordinate system. . Then, division points are calculated between the teaching position and the teaching position according to the order of the teaching position determined sequentially. When the output side end portion moves based on the taught movement locus, it is controlled to move between the taught position and the taught position through the calculated dividing point. Therefore, even if the movement trajectory of the arm part in which the joint is constituted by the driving means that rotates is inevitably curved, the output is because it moves a small distance via the dividing point. The curve of the movement trajectory at the side end can be reduced, and the movement trajectory can be prevented from becoming a large curve.
In addition, since the teaching position is calculated with the coordinates of the orthogonal coordinate system, the position of each division point when the determined teaching position and the next determined teaching position are divided at predetermined intervals is expressed as an orthogonal coordinate system. It can be easily calculated from the coordinates.

A correction unit capable of correcting the teaching position stored in the first storage unit;
The division position calculation means deletes the coordinates of the division point in the second storage means when the teaching position in the first storage means is corrected by the correction means, and again the first position Based on the corrected teaching position in the storage means, the position of each dividing point may be calculated using coordinates in an orthogonal coordinate system including the plane as a coordinate plane.
According to this configuration, when the teaching position is corrected, the division point based on the teaching position before correction is deleted, so there is no fear of malfunction. In addition, since unnecessary data is not stored, it is not necessary to increase the memory capacity of the storage means mounted on the articulated robot, which is advantageous in terms of cost.

Furthermore, a trajectory calculating means for calculating an actual trajectory of the output side end when the output side end is moved between the coordinates of each division point calculated by the division position calculating means, and the trajectory calculating means A distance calculation means for calculating the maximum distance from the straight line connecting the coordinates of the division points of the trajectory calculated by the above, and a third storage means for storing a threshold value of the maximum distance in advance, The division position calculation means compares the maximum distance calculated by the distance calculation means with the threshold of the maximum distance stored in the third storage means, and the maximum distance calculated by the distance calculation means is the threshold value. When the division position calculation means divides the coordinates, the predetermined interval when dividing the coordinates is narrowed, the distance between the positions determined by the teaching operation is divided at a narrowed interval, and the divided points are divided. The position of the plane is the coordinate plane It may be characterized by calculating the coordinate by the orthogonal coordinate system comprising.
By adopting this configuration, it is possible to prevent the movement locus of the output side end portion from drawing a large curve even between the divided points obtained by finely dividing the teaching positions. That is, the output side end can be moved in a state closer to a straight line.

Furthermore, the output side end portion is provided with a holding means for holding the workpiece, and a processing tool for processing the workpiece held by the holding means is within a movement range of the output side end portion. When the work tool is worn, a wear length detecting means for detecting the length of the worn tool is provided, and the wear length detecting means detects the position determined by the determining means. Automatic correction of automatically correcting the coordinates stored in the first storage means and the coordinates stored in the second storage means so as to approach the tool direction by the wear length of the processed tool. A correction means may be provided.
According to this configuration, the teaching position is automatically corrected even when it is impossible to perform accurate machining unless the teaching position is gradually corrected due to wear of the processing tool. The operator can continue using the teaching position without correcting the teaching position.

The output side end is provided with a processing tool for processing the workpiece, and the holding means for holding the workpiece processed by the processing tool is within the movement range of the output side end. When the work tool is worn, wear length detecting means for detecting the length of the worn tool is provided, and the position determined by the determining means is detected by the wear length detecting means. Automatic correction means for automatically correcting the coordinates stored in the first storage means and the coordinates stored in the second storage means so as to approach the tool direction by the wear length of the tool. May be provided.
In this case as well, as in the above-described configuration, the teaching position is automatically corrected even when accurate machining cannot be performed unless the teaching position is gradually corrected due to wear of the processing tool. Therefore, the operator can continue using the teaching position without correcting the teaching position for a long period of time.

The division position calculation means deletes the coordinates of the division points in the second storage means when the teaching position in the first storage means is automatically corrected by the automatic correction means, Again, based on the corrected teaching position in the first storage means, the position of each division point may be calculated using coordinates in an orthogonal coordinate system including the plane as a coordinate plane.
As described above, when the teaching position is automatically corrected, the division point based on the teaching position before the correction is deleted, so there is no fear of malfunction. In addition, since unnecessary data is not stored, it is not necessary to increase the memory capacity of the storage means mounted on the articulated robot, which is advantageous in terms of cost.

  According to the articulated robot according to the present invention, the movement of the output side end can take a movement locus that is almost linear, so that the output side end comes into contact with other parts during the movement operation. There is nothing that can be done safely. This also contributes to shortening the operation time of the output side end.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.
In a multi-joint type robot, a plurality of arm portions are connected, and the connecting portion is operated by rotational drive as a joint, whereby a tool or workpiece (hereinafter simply referred to as a workpiece) held at the output side end portion is predetermined. And automatically performing operations such as welding, grinding, polishing, and assembly.
However, the articulated robot described below is configured such that the output side end portion is provided so as to hold the workpiece, and a processing tool for processing the workpiece is provided separately from the arm portion.
The articulated robot in the present embodiment is provided such that the two arm portions 33 and 34 have three joints and move in a horizontal plane (so that the rotation axis of the joint extends in the vertical direction). A plurality of such arm portions are provided so as to be movable in the vertical direction.

(First embodiment)
First, based on FIG. 1 and FIG. 2, the structure of the axis line which the articulated robot in this embodiment drives is demonstrated.
The drive shaft of the articulated robot 30 in this embodiment is a total of four axes including three rotation axes X, Z, A and one linear movement axis Y. The three rotation axes X, Z, and A constitute a joint as a robot. Also, each joint has a so-called horizontal articulated robot in which the axis directions of the rotation axes X, Z, and A are oriented in the vertical direction and are rotated in a horizontal plane.
Further, the distal end of the arm portion 34 provided with the rotation axis A is the output side end portion 32.

In the articulated robot 30 of the present embodiment, the horizontal plane is set as one coordinate plane in the orthogonal coordinate system. Since it is an orthogonal coordinate system, each coordinate axis direction is represented by x, y, and z. It is assumed that the origin O of the orthogonal coordinates is the center point of the output side end 32 when the output side end 32 is at a predetermined initial position.
Here, the horizontal front direction as viewed from the operator is defined as the + direction of the z axis, the horizontal direction as viewed from the operator is defined as the + direction of the x axis, and the upward direction in the vertical direction is defined as the + direction of the y axis. .
That is, x and z of the coordinates are different from the rotation axes X and Z described above. The coordinate y coincides with the linear movement axis Y.

A specific configuration of the present embodiment will be described with reference to FIGS. 3 and 4.
In the articulated robot 30, a first arm portion 33 and a second arm portion 34 are connected via a joint, and a work (not shown) is connected to an output side end portion 32 on the distal end side of the second arm portion 34. ) Is provided and a work holding means 50 is provided.
The first arm portion 33 is integrally attached to a base (base portion in the claims) 31 on the base side, and rotates in a horizontal plane (xz plane) on the front side of the base 31 ( It can be rotated about the X axis).

The first arm portion 33 can be moved up and down by the moving means 36 (movable in the Y-axis direction). That is, as shown in FIG. 3, the base side of the first arm portion 33 is fixed to the moving body 38 that is moved up and down by the ball screw 37 via the mounting member 39 and moved up and down.
A motor 40 is attached to the upper surface side of the attachment member 39, and a rotation shaft (X axis) of the motor 40 extends downward through the attachment member 39, and the first arm portion 33 extends to the rotation shaft. Is fixed, the first arm portion 33 rotates around the X axis in the horizontal plane (in the xz plane).
An encoder (position detection means) 41 is attached to the motor 40 so that the rotational position of the first arm portion 33 in the X-axis direction from an appropriate reference position can be detected.

  The base 31 is provided with a motor 43 that rotates the ball screw 37. An encoder 45 as a position detection unit is also attached to the motor 43, and the rotational position of the ball screw 37 can be detected. Therefore, the position of the first arm portion 33 in the Y-axis direction can be detected.

The second arm portion 34 is provided on the distal end portion of the first arm portion 33 so as to be rotatable within a plane (horizontal plane: xz plane) parallel to the first arm portion 33.
That is, a motor 47 is attached to the lower surface side of the distal end of the first arm portion 33, and the rotation axis (Z-axis) of the motor 47 extends upward through the first arm portion 33. By fixing the base side of the second arm portion 34 to the shaft, the second arm portion 34 also rotates around the Z axis in the horizontal plane.
An encoder (position detecting means) 48 is also attached to the motor 47 so that the rotational position of the second arm portion 34 on the Z axis can be detected.

A work holding means 50 is attached to the distal end portion of the second arm portion 34.
The work holding means 50 sandwiches and holds a work (not shown) by a lower holding part 51 and an upper holding part (not shown). The lower clamping part 51 is attached to an attachment member 53 attached to the tip of the second arm part 34.

A motor 54 is fixed to the lower surface of the mounting member 53, and a rotating shaft (A axis) of the motor 54 extends upward through the mounting member 53, and the lower clamping portion 51 is fixed to the rotating shaft. Has been. The rotation axis is provided in a direction orthogonal to the rotation plane of the second arm portion 34, that is, in the vertical direction (y-axis direction).
Therefore, the lower clamping unit 51 rotates around the A axis in a plane parallel to the rotation plane (horizontal plane: xz plane) of the second arm unit 34.
An encoder (position detection means) 60 is also attached to the motor 54 to detect the rotational position of the workpiece on the A axis.
Each motor described above is assumed to be a servo motor.

The configuration of the control system of the articulated robot having such a configuration will be described with reference to FIG.
In the articulated robot, the operation of each motor 40, 47, 54, 43 provided on each rotation axis X, Z, A and linear movement axis Y is controlled to perform the teaching operation of the articulated robot. A controller system 62 is provided. As the controller system 62, it is preferable to use a programmable controller that allows an operator to set and input various programs.

The configuration of the controller system 62 will be described.
The controller system 62 controls the servos connected to the motors 40, 47, 54, and 43 so as to control the motors 40, 47, 54, and 43 provided to rotate the arm portions 33 and 34. Circuits 63, 64, 65, 66, a signal processing circuit 70 for sending a set value of rotation of each motor to each servo control circuit, a power supply circuit 71 for supplying power, and the like are provided.

The signal processing circuit 70 is connected to a storage means 69 composed of an HDD or a ROM.
The storage means 69 stores an operation program in which the teaching position of the output side end and the operation command are combined, and an operation program via the dividing point in which the position of the dividing point between the teaching position and the teaching position and the operation command are combined. Is done.
The operation program and the dividing point passing program are created by the program creation means 67 provided in the signal processing circuit 70.
The signal processing circuit 70 reads the operation program or the operation program via the dividing point, and controls the operation of each arm unit 33 and 34.

  The signal processing circuit 70 includes a movement control means 74 which is an execution means for executing an operation program stored in the storage means 69 or an operation program via a dividing point, an output to the servo control circuits 63 to 66, and an operation panel 77. An OS 72 (Operating System) for controlling the entire operation based on an input signal from a manual pulse generator (not shown) is provided.

  The signal processing circuit 70 is provided with position calculation means 99 that can calculate the position of the output side end portion 32 in an orthogonal coordinate system. The position calculating means 99 determines the position of the output side end portion based on the respective rotational positions of the encoders 41, 48, 60, 45 provided in the motors 40, 47, 54, 43 of the arm portions 33, 34. Can be calculated by an orthogonal coordinate system.

Further, the signal processing circuit 70 divides each teaching position between each teaching position from each teaching position of the operation program stored in the storage means 69 at a predetermined interval, and each of the divided points (hereinafter referred to as the respective points). A division position calculation means 73 is provided for calculating coordinates in the orthogonal coordinate system (referred to as division points).
The program creation means 67 described above creates a program via division points that combines the orthogonal coordinates of the division points calculated by the division position calculation means 73, the orthogonal coordinates of each teaching position of the operation program, and the operation command.
The movement control means 74, the OS 72, the position calculation means 99, the program creation means 67, the divided position calculation means 73, and the like are based on the CPU, ROM, RAM, and other memories in the signal processing circuit 70, and programs for operating the CPU. Has been built.

The memory area in the storage means 69 will be described with reference to FIG.
As memory areas in the storage means 69, areas 100, 101, 102, and 103 are set as areas for storing machine parameters, areas for storing program information, auxiliary macro areas, and spare areas, respectively.
An operation program is stored in the area 104, and a program via a dividing point is stored in the area 105.

  The servo control circuits 63 to 66 are fed back with position signals and speed signals from the encoders 41, 48, 60, and 45 provided in the motors 40, 47, 54, and 43. Based on the setting signal sent, control is performed so that the difference from the feedback signal becomes small.

The operation panel 77 includes a touch panel type operation switch 80 (see FIG. 7), a display device (not shown) for displaying the position of the current output side end, and the position of the output side end. A manual pulse generator (not shown) for adjustment is provided.
The “write ENT” switch 82 of the operation switch unit 80 serves as a determination unit when the operator determines the teaching position.

Next, a teaching operation in the articulated robot having the above-described configuration will be described.
When performing the teaching, the operator operates the operation panel 77 to start execution of the teaching operation. Then, the output side end portion 32 can be moved by the operator directly holding the arm portions 33 and 34, operating the operation switch unit 80 operated by the operator, or operating the manual pulse generator. It becomes.
As shown by reference numerals 84, 86, 87, 88, 96, and 97 in FIG. 7, the operation switches for the operator to move are made to be movable in the orthogonal coordinate system to the operation switch unit 80 of the touch panel. Is provided.

When the operator moves the output side end 32 by operating the operation switches 84, 86, 87, 88, 96, 97, the operator sets the moving direction of the output side end 32 to the orthogonal coordinate system. 7 is selected and the switch 84, 86, 87, 88, 96, 97 in FIG. 7 is pressed.
Then, a switch operation signal is input from the operation panel 77 to the signal processing circuit 70 for the time when each switch is pressed. The signal processing circuit 70 outputs a setting signal to the servo control circuits 63 to 66 so that the output side end 32 moves in the corresponding direction only for the time when each switch is pressed.
In this way, each of the control circuits 63 to 66 has the motors 40, 47, 66 so that the output side end 32 moves by the designated distance on the orthogonal coordinate axis designated by the operation switch unit 80. 54 and 43 are controlled.

  When the output side end portion 32 moved by the operator holding the arm portions 33 and 34 directly by hand or operating the switch of the operation switch portion 80 reaches a predetermined position, the operator When the write ENT switch 82 is operated, a determination instruction signal is input from the operation panel 77 to the signal processing circuit 70. The position calculation means 99 of the signal processing circuit 70 that has received the determination instruction signal calculates the position of the output side end 32 in the orthogonal coordinate system at the time of receiving the determination instruction signal.

The program creation means 67 of the signal processing circuit 70 creates an operation program based on the orthogonal coordinates of the teaching position calculated by the position calculation means 99.
In this way, the teaching position in the operation program stored in the storage unit 69 is data in an orthogonal coordinate system. That is, the distance from the origin in the x-axis direction, the distance from the origin in the z-axis direction, and the distance from the origin in the y-axis direction are stored as coordinates of each teaching position.

Then, the operator moves the output side end 32 to the next teaching position. As described above, the moving method is performed by either an operator holding the arm portions 33 and 34 directly by hand, an operation of the operation switch 80, or a manual pulse generator. Also good.
When the operator operates the writing ENT switch 82 when the output side end 32 reaches the next teaching position, a determination instruction signal is input from the operation panel 77 to the signal processing circuit 70. The position calculation means 99 of the signal processing circuit 70 that has received the determination instruction signal calculates the position of the output side end 32 in the orthogonal coordinate system at the time of receiving the determination instruction signal.
The program creation unit 67 creates a continuation of the operation program based on the orthogonal coordinates of the teaching position calculated by the position calculation unit 99.

In this way, the operator sequentially determines the teaching position while moving the output side end 32, and the operator ends the teaching when the final teaching position is taught.
Then, an operation program in which the coordinates of the teaching position are stored in order is stored in the area 104 of the storage unit 69.

Of course, the movement trajectory of the output side end 32 also differs depending on the type of workpieces installed at the output side end 32. For this reason, in the articulated robot of the present invention, it is possible to create a plurality of operation programs by executing teaching for each different workpiece.
A plurality of operation programs can be stored in the area 104 of the storage unit 69.

Next, an operation during actual work of the articulated robot that has completed the above-described teaching operation will be described.
First, the operator operates an operation switch unit 80 provided on the operation panel 77 to read out a corresponding operation program from the storage unit 69.
Then, the operator holds the workpiece in the workpiece holding means 50 and causes the operation program stored in the storage means 69 to be executed.

  The operation program is executed in the signal processing circuit 70 so that the position of the output side end 32 moves to the teaching position written in the operation program based on the operation program read from the storage means 69. This is done by the control means 74 outputting setting signals to the servo control circuits 63-66. Each servo control circuit 63 to 66 operates each motor so as to move the output side end 32 to each teaching position stored as an operation program.

During the first operation (machining of the first workpiece) based on the operation program, the division position calculation unit 73 of the signal processing circuit 70 outputs the movement control unit 74 to each teaching position in the operation program on the output side. While moving the end portion 32, the distance between the teaching positions is calculated, and the distance is divided at predetermined intervals.
Then, the division position calculation unit 73 calculates the coordinates in the orthogonal coordinate system of the division points divided at predetermined intervals.
When the division position calculation unit 73 calculates the coordinates of the division point in the orthogonal coordinate system, the program creation unit 67 creates a program via the division point that combines the coordinates of the teaching position, the coordinates of the division point, and the operation command.
The dividing point passing program is stored in the area 105 of the storage unit 69.

After the first operation is completed, the operator removes the processed workpiece, attaches an unprocessed workpiece, and operates the operation switch unit 80 to start the second operation.
When the first operation is completed, the movement control unit 74 of the signal processing circuit 70 takes the program via the division point from the area 105 of the storage unit 69 and performs the second and subsequent operations based on the program via the division point. Run the action.
Therefore, after the second time, the output side end 32 operates so as to pass through each division point between the teaching position taught in the teaching operation and the teaching position.

  Note that this division point passing program is deleted from the area 105 of the storage means 69 when the predetermined operation is terminated and the articulated robot is stopped. That is, when the operation program is read again from the region 104 and executed, the first operation is executed based on the operation program read from the region 104, and the program via the dividing point is again executed during the first operation. Will be created.

In the present embodiment, the operation program stored in the storage unit 69 can be modified by the operator.
That is, the operator operates the operation switch unit 80 to read out the operation program to be corrected from the storage unit 69 and display the contents of the program on the display unit. An example of the operation program displayed on the display means is shown in FIG.
The operator can freely correct each coordinate of the teaching position to be corrected by looking at the coordinates of each teaching position in the operation program displayed on the display means. The corrected operation program is stored in the storage unit 69 again. At this time, the operator can select whether to overwrite and store the operation program before correction.

When the operation program is corrected during the execution of the operation, it is necessary to correct the program via the dividing point created based on the operation program.
Therefore, when the operation program is corrected during the execution of the operation, the division position calculation means 73 of the signal processing circuit 70 deletes the program via the dividing point in the storage means 69 and again performs a new division based on the corrected operation program. Calculate the Cartesian coordinates of the points. Then, the program creation unit 67 creates a new program via a division point by combining the orthogonal coordinates of the division point calculated by the division position calculation unit 73, the orthogonal coordinates of the corrected teaching position, and the operation command.
The newly created division point passing program is stored in the area 105 of the storage means 69.

(Second Embodiment)
A second embodiment will be described.
In the articulated robot of the second embodiment, it is possible to determine whether or not the interval between the dividing points is appropriate and automatically correct the interval between the dividing points.
9 is a block diagram of the present embodiment, FIG. 10 is an explanatory diagram for explaining the locus of the output side end portion of the present embodiment, and FIG. 11 is a case where the teaching positions are divided at a predetermined interval when the interval is narrowed. It is explanatory drawing explaining the locus | trajectory of the output side edge part.
In addition, the same code | symbol is attached | subjected about the structure same as 1st Embodiment mentioned above, and description may be abbreviate | omitted.

  The signal processing circuit 70 according to the present embodiment includes an output side end portion between a predetermined division point and a division point when the output side end portion 32 moves through the division point calculated by the division position calculation means 73. A trajectory calculating means 90 is provided for calculating the actual trajectory a.

Further, the signal processing circuit 70 calculates a distance for calculating a maximum distance c between the locus a calculated by the locus calculator 90 and a straight line b between the predetermined dividing point having the locus and the dividing point. Means 91 are provided.
The signal processing circuit 70 is connected to a storage means 92 that stores a threshold value for a maximum distance between the actual trajectory calculated by the distance calculation means 91 and the straight line. The storage unit 92 may be the same storage unit as the storage unit 69 storing the operation program or the like, or may be a separate storage unit.

Then, the division position calculation means 73 provided in the signal processing circuit 70 compares the maximum distance c obtained by the distance calculation means 91 with the threshold value extracted from the storage means 92. As a result of the comparison, if the maximum distance c is within the threshold value, the position calculated by the division position calculation means 73 remains as it is, and the program via the division point is not corrected.
However, as a result of the comparison, if it is found that the maximum distance exceeds the threshold, the division position calculation means 73 reduces the division interval between the teaching positions again as shown in FIG. Is calculated.

In order to verify the division points set again, the trajectory calculation means 90 again calculates the actual trajectory a ′ between the predetermined division points, and the distance calculation means 91 maximizes the straight line b ′ connecting the division points. The distance is calculated, and the division position calculation means 73 compares the calculated maximum distance c ′ with the threshold value.
If the maximum distance c ′ is within the threshold value, the position calculated by the division position calculation unit 73 remains the same. If the maximum distance c ′ exceeds the threshold value, the division position calculation unit 73 determines the division between the teaching positions. The position of the dividing point is calculated again with the interval narrowed.
As described above, according to the present embodiment, the setting of the dividing points is adjusted so that the actual trajectory between the dividing points is closer to a straight line, and the output side end portion 32, the arm portion 33, It is possible to prevent 34 from coming into contact with other parts and slowing down the operation speed.

(Third embodiment)
The articulated robot of this embodiment can automatically correct the operation program in accordance with the wear of the processing tool. A block diagram of this embodiment is shown in FIG. 12, and a schematic configuration is shown in FIGS.
In addition, about the component same as embodiment mentioned above, the same code | symbol is attached | subjected and description may be abbreviate | omitted.

The processing tool 110 according to the present embodiment is a rotating disk-shaped grinding wheel for contacting a work to deburr the work. The grinding wheel 110 is rotationally driven by a motor 112.
A sensor 114 that detects the grinding wheel 110 is provided near the tip of the grinding wheel 110. As the sensor 114, an optical sensor or the like can be used. The sensor 114 corresponds to the wear detection means in the claims.
The sensor 114 is installed at a position where the grinding wheel 110 is slightly worn away from being worn away. It is assumed that the sensor 114 is disposed at a position moved in a wear direction by a predetermined distance from a state where the grinding wheel 110 is not worn at all.
The sensor 114 outputs a detection signal to the signal processing circuit 70 when the grinding wheel 110 is worn and the wear reaches the position of the sensor 114.
When the automatic correction means 85 in the signal processing circuit 70 receives the detection signal from the sensor 114, the automatic correction means 85 is an operation program being executed based on the correction value for correcting the position of the sensor 114 stored in the storage means 83 in advance. Make corrections.

According to the example shown in FIG. 14, the wear direction of the grinding wheel is the + z direction. Here, assuming that the position of the sensor 114 is previously set at a position 1 mm from the tip of the unworn grinding wheel 110, the automatic correction means 85 adds +1 mm to all the teaching positions in the z direction in the operation program being executed. Correct to value.
When the operation program is corrected, the signal processing circuit 70 erases the program via the dividing point in the area 105. Then, the movement control means 74 executes the first operation after correction based on the teaching position described in the operation program after correction, and at the same time, the division position calculation means 73 performs division points based on the operation program after correction. The coordinates of are calculated. The program creation means 67 newly creates a program via division points based on the teaching position of the automatically corrected operation program. A new program via the dividing point, in which the teaching position is further advanced in the direction of the grinding wheel 110 due to wear of the grinding wheel 110, is stored in the area 105 of the storage means 69.

  Note that the processing tool 110 according to the present embodiment is installed at a location distant from the arm portions 33 and 34, and the work 120 as a workpiece is held at the output side end 32. May be provided at the output side end portion 32 and the work may be installed at a location away from the arm portions 33 and 34.

In the above-described embodiment, the case where only one sensor is installed has been described. However, by providing a plurality of sensors at predetermined intervals from the tip of the grinding wheel toward the wear direction, the wear of the grinding wheel can be detected in a finer range.
Also in this case, every time any one of the plurality of sensors detects wear of the grinding wheel, the operation program is corrected in accordance with the detected position of the sensor, and a program via division points is newly created.

(Other embodiments)
In the embodiment described above, when a certain operation program is executed, first, in the first operation, the operation is executed based on the operation program in which the teaching position is described, and a plurality of dividing points are provided between the teaching positions. Is calculated, and a program via a dividing point describing the operation via the dividing point is created at the same time.
However, the present invention for calculating the dividing points is not limited to such an embodiment. For example, after the teaching operation is completed and an operation program in which only the teaching position is set is created, before the operation program is executed, the operation program may be analyzed to create a program via division points. Further, during the teaching operation, a program via division points may be created in parallel with the creation of the operation program.

  Further, in each of the above-described embodiments, the storage unit 69 has created an operation program and a program via division points created based on the operation program. However, the movement control means 74 not only executes based on the program, but also executes movement control of the arm portions 33 and 34 based on the teaching position and the orthogonal coordinates of the dividing points stored simply as data. Also good.

  In addition, the form which combined Embodiment 2 and Embodiment 3 with Embodiment 1 mentioned above is naturally possible.

Also, as described above, before executing the motion program, analyze the motion program to create a program via division points, or create a program via division points in parallel with the creation of the motion program during teaching operation. In this case, in the memory area shown in FIG. 6, the memory capacity of the program storage area 105 via the dividing point is small.
For this reason, as shown in FIG. 15, a memory card 131 may be added to the storage unit 69.
In this case, the memory area of the storage means 69 includes an area for storing machine parameters, an area for storing program information, an auxiliary macro area, a directory area, and a spare area in the areas 140, 141, 142, 143, and 144, respectively. Settings are made.
An area where only one operation program can be stored is secured in the area 145, and a program via a dividing point is stored in the area 146.

  Thus, by adding the memory card 131, a storage capacity sufficient to store both the operation program and the program via the dividing point in association with each other can be secured. For this reason, even if the operation program is not read out and the dividing point passing program is not created during the first execution as in the first embodiment, the dividing point passing program can also be created during the teaching operation for creating the operation program. It can be done.

FIG. 16 shows an aspect of a memory area in which the operation program storage area and the division point via program storage area are each divided into two. Note that the same components as those in the memory area shown in FIG.
In the memory area of FIG. 16, the operation program storage area 145 is divided into an operation program storage area 145A and an operation program storage area 145B. Here, the movement control means 74 reads the operation program currently being executed from the memory card 131 and stores it in the operation program storage area 145A. When the operator designates an operation program to be executed next, The operation program to be executed can be read from the memory card 131 and stored in advance in the operation program storage area 145B. Therefore, when the next operation program is executed, the operation program can be executed more quickly than in the case where the operation program is searched from the memory card 131.

  Further, the program storage area via the dividing point is also divided into two areas 146A and 146B. For the program via the dividing point, the movement control means 74 also uses the program via the dividing point for the program via the dividing point currently being executed. 146A, when the operator designates a program via a division point to be executed next, the program through the division point to be executed next is read from the memory card 131 and stored in the program storage area 145B via a division point. It can be stored in advance. For this reason, when executing the next program via the dividing point, the operation can be executed more quickly than when the program via the dividing point is searched from the memory card 131.

(Example)
As an example of the apparatus using the articulated robot described above, a workpiece processing apparatus that processes a workpiece will be described.
17 is a front view of the workpiece machining apparatus, FIG. 18 is a plan view of the workpiece machining apparatus, and FIG. 19 is a side view of the workpiece machining apparatus.
Reference numeral 110 denotes a grinding wheel as a processing tool, reference numeral 111 denotes a bearing of the rotating shaft, and reference numeral 112 denotes a motor for driving the grinding wheel 110. The grinding wheel 110, the bearing 111, and the motor 112 are supported on the base 31 so that the rotation axis of the grinding wheel is horizontal.
The workpiece processing apparatus 130 of this embodiment includes a grinding wheel 122 that is smaller than the grinding wheel 110. The small grinding wheel 122 is attached to the bearing 121 and has a rotation shaft that is parallel to the rotation shaft of the large grinding wheel 110. Reference numeral 124 denotes a motor that drives a small grinding wheel 122.

The small grinding wheel 122 is attached to the periphery of the rotating shaft of the grinding wheel 110 by a rotating arm 123 so as to be rotatable. The rotation of the small grinding wheel 122 is indicated by an arrow d in FIGS.
Further, the grinding wheel 110 and the grinding wheel 122 and the motors 112 and 124 for driving them are attached to the base 31 so as to be rotatable in a vertical plane. The rotation of each grinding wheel or the like is represented by an arrow e in FIG. Reference numeral 125 denotes a motor for rotating these grinding wheels and the like in a vertical plane.

  In the present embodiment, two types of grinding wheels are provided as an example, and a work processing apparatus in which these rotation shafts rotate in a vertical plane has been described. However, the present invention is limited to this. However, there may be only one grinding wheel, and the grinding wheel may not be configured to rotate with the rotating shaft.

The workpiece 120 that is a workpiece to be processed by the grinding wheels 110 and 122 is placed on the output side end 32.
The workpiece 120 is processed by moving the output side end 32 so that the workpiece 120 contacts the grinding wheels 110 and 122 at various angles. Therefore, prior to the machining process of the workpiece 120, it is necessary to perform teaching to input the movement locus of the workpiece 120 by moving the output side end portion 32 on which the workpiece 120 is placed.

  Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. .

It is explanatory drawing explaining the schematic structure of an articulated robot. It is explanatory drawing explaining the schematic structure of an articulated robot. It is a side view explaining the specific structure of an articulated robot. It is a top view explaining the specific structure of an articulated robot. It is a block diagram explaining the structure of a control system. It is explanatory drawing explaining the memory area of a memory | storage means. It is explanatory drawing explaining the structure of an operation switch part. It is explanatory drawing which shows an example of an operation program. It is a block diagram of 2nd Embodiment. It is explanatory drawing which shows the movement locus | trajectory of the output side edge part between teaching positions. It is explanatory drawing explaining the case where the division | segmentation space | interval between teaching positions is narrowed. It is a block diagram of a 3rd embodiment. It is a side view which shows schematic structure of 3rd Embodiment. It is a top view which shows schematic structure of 3rd Embodiment. It is explanatory drawing explaining the memory area | region at the time of adding a memory card. It is explanatory drawing explaining the other structure of a memory area. It is a front view of a workpiece machining apparatus when the articulated robot of the present invention is applied to the workpiece machining apparatus. It is a top view of the workpiece | work processing apparatus shown in FIG. It is a side view of the workpiece processing apparatus shown in FIG. It is explanatory drawing explaining operation | movement of an articulated robot. It is explanatory drawing explaining the continuation of operation | movement of the articulated robot of FIG. It is explanatory drawing which shows the movement locus | trajectory of the output side edge part of an articulated robot.

Explanation of symbols

30 Articulated robot 31 Base (base)
32 Output side end portion 33, 34 Arm portion 36 Moving means 37 Ball screw 38 Moving body 39 Mounting member 40, 43, 47, 54 Motor 41, 48, 60, 45 Encoder 50 Work holding means 51 Lower clamping portion 53 Mounting member 62 Controller system 63, 64, 65, 66 Servo control circuit 67 Program creation means 69, 83, 92 Storage means 70 Signal processing circuit 71 Power supply circuit 73 Division position calculation means 74 Movement control means 77 Operation panel 80 Operation switch sections 82, 84, 86, 87, 88, 96, 97 Switch 85 Automatic correction means 90 Trajectory calculation means 91 Distance calculation means 99 Position calculation means 100 Machine parameter storage area 101 Program information storage area 102 Auxiliary macro area 103 Spare area 104 Operation program storage area 105 Division Program storage area via points 110 and 122 processing tool (grinding wheel)
111, 121 Bearing 112, 124, 125 Motor 114 Sensor 120 Workpiece 123 Rotating arm 130 Workpiece processing device O Origin X, Z, A Rotation axis Y Linear movement axis

Claims (7)

A plurality of arm parts whose base parts are connected to the tip part of the base part or the adjacent arm part so as to be rotatable in the same plane or in a parallel plane; and drive means for driving the arm parts to rotate in the plane. In an articulated robot comprising:
Position calculating means for calculating the position of the output side end portion provided at the tip by coordinates in an orthogonal coordinate system including the plane in the coordinate plane;
A first storage means for storing coordinates in the orthogonal coordinate system of the output side end at any of a plurality of teaching positions on a movement locus of the output side end during a teaching operation;
The distance between the teaching positions is calculated based on the coordinates stored in the first storage means in the order determined in the teaching operation, the distance is divided at predetermined intervals, and the divided divisions are calculated. Division position calculation means for calculating the position of the point by coordinates in an orthogonal coordinate system including the plane in the coordinate plane;
Second storage means for storing the coordinates of the dividing points calculated by the dividing position calculating means;
When the output side end is moved to the determined plurality of teaching positions, the output side end passes through the division point calculated by the division position calculation means between the teaching position and the teaching position. And a movement control means for controlling the rotation of the driving means so as to move. Comprising correction means capable of correcting the teaching position stored in the first storage means;
The division position calculating means includes
When the teaching position in the first storage means is corrected by the correction means, the coordinates of the division point in the second storage means are deleted, and again after the correction in the first storage means 2. The articulated robot according to claim 1, wherein the position of each division point is calculated based on the taught position by coordinates based on an orthogonal coordinate system including the plane as a coordinate plane. Trajectory calculation means for calculating an actual trajectory of the output side end when the output side end is moved between the coordinates of each division point calculated by the division position calculation means;
Distance calculating means for calculating a maximum distance from a straight line connecting the coordinates of the division points of the locus calculated by the locus calculating means;
Third storage means for storing a threshold value of the maximum distance in advance,
The division position calculating means includes
When the maximum distance calculated by the distance calculation means is compared with the threshold of the maximum distance stored in the third storage means, and the maximum distance calculated by the distance calculation means exceeds the threshold The division position calculation means divides a predetermined interval when dividing the coordinates, divides the distance between the positions determined by the teaching operation at an interval narrowed, and sets the position of each divided point to the plane. The multi-joint type robot according to claim 1 or 2, wherein the multi-joint type robot is calculated by coordinates based on an orthogonal coordinate system including a coordinate plane. The output side end is provided with a holding means for holding the workpiece,
A processing tool for processing the workpiece held by the holding means is provided within the movement range of the output side end,
When the processing tool is worn, wear length detection means for detecting the length of the worn portion is provided,
The coordinates stored in the first storage unit and the first position are set so that the position determined by the determination unit approaches the processing tool direction by the wear length of the processing tool detected by the wear length detection unit. The articulated robot according to any one of claims 1 to 3, further comprising an automatic correction unit that automatically corrects coordinates stored in the storage unit. The division position calculating means includes
When the teaching position in the first storage means is automatically corrected by the automatic correction means, the coordinates of the division points in the second storage means are deleted, and again in the first storage means. The articulated robot according to claim 4, wherein the position of each division point is calculated based on an orthogonal coordinate system including the plane in a coordinate plane based on the corrected teaching position. The output side end is provided with a processing tool for processing the workpiece,
A holding means for holding a workpiece to be processed by the processing tool is provided within the movement range of the output side end,
When the processing tool is worn, wear length detection means for detecting the length of the worn portion is provided,
The coordinates stored in the first storage unit and the first position are set so that the position determined by the determination unit approaches the processing tool direction by the wear length of the processing tool detected by the wear length detection unit. The articulated robot according to any one of claims 1 to 3, further comprising an automatic correction unit that automatically corrects coordinates stored in the storage unit. The division position calculating means includes
When the teaching position in the first storage means is automatically corrected by the automatic correction means, the coordinates of the division points in the second storage means are deleted, and again in the first storage means. The articulated robot according to claim 6, wherein the position of each division point is calculated based on the corrected teaching position using coordinates in an orthogonal coordinate system including the plane in a coordinate plane.

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