JPH0724762A - Robot controller - Google Patents

Abstract

PURPOSE:To facilitate setting of a scope of permissible action so as to improve work efficiency by specifying a scope of permissible three-dimensional action by a shape and space coordinate having the predetermined relationship. CONSTITUTION:Shape selection menu of a scope of possible action is displayed on CRT 27 of an operation panel 26 and shape is selected through key inputting. The selected shape specification data is stored in DDA region of a memory 25. Next, input point of data related to position and size is displayed on the CRT 27 based on the shape data stored in FDA region of the memory 25. A worker moves a tip of a robot to a position on the displayed space coordinate system in an actual space to store a coordinate value of the position in the DDA region. Next, the actual scope of three-dimensional action is computed and determined from this input coordinate. Further, a teaching point data is read from PDA region of the memory 25 to compute position coordinate of an interpolation point. If it is in the scope of possible action, the tip of robot is positioned and controlled at the interpolation point, and if it is out of the scope, it is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot controller for controlling the position and orientation of a robot. In particular, the present invention relates to a device for ensuring work safety by limiting the operating range of the tip portion of a robot.

[0002]

2. Description of the Related Art Conventionally, as described in Japanese Patent Laid-Open No. 60-44293, there is known a device for presetting an operation permission range of a tip position of a robot. In that device, the method of directly inputting the coordinates of the corner points of the rectangular parallelepiped in the spatial coordinate system, and in the spatial coordinate system, the tip point of the robot is actually positioned at the corner point of the rectangular parallelepiped, and the coordinates of that position are calculated. The method of remembering is adopted. Then, when the target position of the tip of the robot is in the operation permission range at the time of teaching and playback, the robot can be positioned at the target point within the range, and when the target position is outside the range, , The positioning to the target position is prohibited.

[0003]

Although the safety in the positioning control of the robot is ensured by setting the operation permission range as described above, the shape of the set range is limited to a rectangular parallelepiped, and the robot performs it. It was not always suitable for various machining operations. Further, there is a problem that setting such an operable range is complicated and requires a lot of time. The present invention has been made to solve the above-mentioned problems, and an object thereof is to improve work efficiency and work safety by facilitating setting of an operable range that can be permitted to a robot. Is to improve.

[0004]

According to a first aspect of the present invention for solving the above-mentioned problems, a robot controller for controlling a position and a posture of a robot has a shape for designating and inputting a shape within a three-dimensional movable range. Designating means, position designating means for designating a position in the three-dimensional movable range in the spatial coordinate system by designating points having a predetermined relationship with the three-dimensional movable range in the spatial coordinate system, and designated shape. Based on the position and the position, a calculation unit that calculates data that specifies the actual three-dimensional operable range in the spatial coordinate system, and the target position of the positioning control when the position and the posture of the robot are controlled, the tip portion of the robot is the actual position. If the control target position is not within the actual three-dimensional operable range by the determining means and the determining means for determining whether the control target position exists within the three-dimensional operable range, Characterized by providing an operation inhibiting means for inhibiting the positioning control to the control target position.

Further, the invention of claim 2 is characterized in that, in order to specify the three-dimensional movable range, it is carried out by actually moving and positioning the tip of the robot in the spatial coordinate system. Further, the inventions of claims 3 and 4 are characterized in that the motion prohibited area can be partially removed from the three-dimensional movable range determined by the shape, position, and size data. .

[0006]

When the three-dimensional movable range of the tip of the robot is set in the spatial coordinate system, data designating the shape of the three-dimensional movable range to be set and the set position of the range are input. The existing area of the actual three-dimensional operable range in the spatial coordinate system is calculated. Next, when the positioning operation of the tip end portion of the robot is actually executed, it is determined whether or not the control target position of the tip end portion of the robot is within the set actual three-dimensional operable range. Positioning control to the control target position is executed only when the position is within the range. Further, when a partial operation prohibited area is set from the operable area, the three-dimensional operable area excluding the operation prohibited area is calculated, and the tip of the robot is positioned only within the operable area. It becomes possible to control.

[0007]

As described above, according to the present invention, the three-dimensional movable range is set in the spatial coordinate system by designating the shape and the coordinates of the points having a predetermined relationship with the range in the spatial coordinate system. The actual three-dimensional operable range is calculated. Therefore, in particular, since the shape of the movable range can be arbitrarily selected, it is extremely easy to set the movable range according to the type of the workpiece and the work, and the workability is improved. Further, when the setting of the three-dimensional operable range is input by positioning the tip of the actual robot, the operator can easily imagine the operable range, and the setting of the range becomes extremely easy. . Further, in the three-dimensional movable range, the motion prohibited area can be easily set partially. Therefore, when an obstacle exists within the movable range specified by the basic shape, the obstacle exists. It is possible to easily remove the area as the operation prohibited area, the work of setting the operable range in this case is extremely easy, and the operable range can be determined in detail, so that the safety of the work is further ensured.

[0008]

EXAMPLES The present invention will be described below based on specific examples. FIG. 1 is a mechanism diagram showing the mechanism of a 6-axis articulated robot. 10 is the robot body, and the body 1 is on the floor
A base 12 for fixing 0 is disposed, and a column 13 is fixedly mounted on the base 12, and the column 13 includes a body 14
Is rotatably arranged. The body 14 rotatably supports the upper arm 15, and the upper arm 15 rotatably supports the forearm 16. Body 1
4, the upper arm 15 and the forearm 16 are rotationally driven about axes a, b, and c by servomotors M1, M2, and M3 (see FIG. 2), respectively. This rotation angle is detected by the encoders E1, E2, E3. A wrist 17 is rotatably supported on the tip of the forearm 16 about the d axis, and a hand 18 is rotatably supported on the wrist 17 about the e axis.

Further, the hand 18 is rotatably supported around the f axis, and the welding torch T is attached to the hand 18. Then, the workpiece W is processed by the welding torch T. The d-axis, the e-axis, and the f-axis are driven by servomotors M4, M5, and M6.

FIG. 2 is a block diagram showing the electrical configuration of the robot attitude control device. Reference numeral 20 is a central processing unit including a microcomputer and the like. A memory 25, servo CPUs 22a to 22f for driving a servo motor, an operation panel 26 for instructing jog operation, instruction of a teaching point, and the like, and a laser oscillator 23 for welding are connected to the central processing unit 20. There is. The operation panel 26 is provided with a CRT 27 for displaying various data. A welding torch T is connected to the laser oscillator 23. The servo motors M1 to M6 for driving the axes a to f attached to the robot are respectively the servo CPU 2
It is driven by 2a to 22f.

Each of the servo CPUs 22a to 22f outputs output angle data θ output from the central processing unit 20.
The deviations between _{1 to} θ ₆ and the outputs α _{1 to} α ₆ of the encoders E1 to E6 connected to the servo motors M1 to M6 are calculated, and each servo is operated at a speed according to the magnitude of the calculated deviation. It operates so as to rotate the motors M1 to M6.

The memory 25 has a PA area in which a program for operating the robot according to the teaching point data is stored, a PDA area in which the teaching point data representing the position and orientation of the robot is stored, and data for specifying the three-dimensional operable range. Is formed for each shape, and a DDA area for storing shape designation data, position designation data, and size designation data necessary to set the actual three-dimensional operable range.

Next, the operation will be described. FIG. 3 is a flowchart showing a processing procedure regarding teaching of the CPU 20 used in the apparatus of the embodiment. First, in step 100, a menu for selecting the shape of the operable range is displayed on the CRT 27 of the operation panel 26, and the shape is selected by the operator's key input. The shape of the operable range is a rectangular parallelepiped, a sphere, a cylinder, or the like. The selected shape designation data is stored in the DDA area of the memory 25. The operator determines the shape of the movable range of the tip of the robot according to the type of machining of the workpiece. Next, at step 102, as shown in FIG. 5, based on the shape data stored in the FDA area of the memory 25, the input point of the data regarding the position and the size is displayed on the CRT 27. For example, when a rectangular parallelepiped is selected as the shape of the operable range,
As shown in, the data input point A of the shape and position of the rectangular parallelepiped
And the data input point B of the size are displayed. The input point B and the input point A are on a diagonal line.

Next, in step 104, the operator assumes a three-dimensional movable range of the selected shape in the real space, and at the same time, the spatial coordinate system corresponding to the data input point A at the position displayed on the CRT 27. The tip of the robot is moved to the upper position. This is performed by the jog operation by the operator operating the operation panel 26. Next, in step 106, it is judged whether or not the data set key of the operation panel 26 has been pressed. If the data set key has been pressed, in step 108, in the spatial coordinate system of the data input point A of the position. Coordinate value (A _x, A _y, A _z )
Are stored in the DDA area of the memory 25. The coordinate value of the tip of the robot can be obtained by coordinate conversion of the current angle of each axis of the robot. If the data set key is not pressed, the positioning operation by the jog operation in step 104 is repeatedly executed.

Next, in step 110, similarly, in the actual space, the three-dimensional movable range of the selected shape is assumed and the data input point B of the size shown in FIG. The tip of the robot is moved to a position on the corresponding spatial coordinate system by a jog operation. Next, in step 112, it is determined whether or not the data set key of the operation panel 26 is pressed. If the data set key is pressed, in step 114, the spatial coordinate system of the data input point B of the size is determined. Coordinate values at (B _x, B
_y, B _z ) is stored in the DDA area of the memory 25. or,
If the dataset key is not pressed, step 11
The positioning operation by the jog operation of 0 is repeatedly executed.

Next, in step 116, step 10
The coordinates and step of the data input point A of the position input in 8.
Data specifying the actual three-dimensional operable range is calculated from the coordinates of the data input point B having the size input at 114. In the example of the rectangular parallelepiped shown in FIG. 4, the position data input point A
And the size data input point B are on a diagonal line. Accordingly, the displacement with respect to the data input point A of the position of the size of the data input point _{B (E x, E y,} E z) = (B x -A x, B y -A y,
B _z −A _z ) is calculated. This displacement (E _x, E _y, E _z )
And the coordinate value (A _x, A _y, A _z ) of the position data input point A determines the actual three-dimensional operable range.

Next, the positioning and posture control of the robot will be described. The CPU 20 executes the procedure shown in FIG. In step 200, the teaching point data stored in the PDA area of the memory 25 is read out, and then step 202
Then, the position coordinates (X,
Y, Z) are interpolated. Then, in step 204, it is calculated that the interpolation point (X, Y, Z) at the tip of the robot exists in the actually set three-dimensional operable range. That is, it is determined whether or not an interpolation point exists within the three-dimensional operable range shown in FIG. If it is determined in step 206 that the interpolation point is within the three-dimensional operable range, the tip of the robot is position-controlled to the interpolation point calculated in step 202 in step 208.
On the other hand, if it is determined in step 206 that the interpolation point does not exist in the three-dimensional operable range, step 210
At, the positioning operation to the interpolation point is stopped.

As described above, in the spatial coordinate system,
It is possible to set the three-dimensional movable range of the tip of the robot, and to prohibit the positioning operation when the positioning target point does not exist in the three-dimensional movable range. Therefore, the setting of the three-dimensional operable range becomes extremely easy, and danger in the position and attitude control operation of the robot can be prevented.

In the above embodiment, the tip of the robot is actually moved to the designated point in the spatial coordinate system according to the display of the shape of the movable range on the CRT 27, and the coordinate value of the point is stored. ing. However, from the control panel 26,
The coordinate value of the data input point A at the position shown in FIG. 4 and the coordinate value of the data input point B of the size may be directly input as numerical values.

Further, when the three-dimensional movable range is designated by a sphere, as shown in FIG. 7, the center of the sphere is used as a position data input point A, and an arbitrary point B on the sphere is used as size data. It may be the input point B. In the case of this sphere, the radius r of the sphere is calculated from the arbitrary point B and the center point A on the sphere as size data. In the case of a sphere, three points on the spherical surface may be designated.

In the case of a cylinder, as shown in FIG.
The center point A of the bottom surface is the position data input point A, and the arbitrary point B on the circumference of the bottom surface and the arbitrary point C in the height direction (z-axis direction) are the size data input points B and C. be able to.
Further, even if it is a point other than this, the position data input point and the size data input point can be arbitrarily designated as long as they can define a cylinder.

In the embodiment described above, different shapes such as a rectangular parallelepiped, a sphere and a cylinder can be designated, but it is not always necessary to prepare different shapes for the shape designation data. For example, as shown in FIG. 9, a rectangular parallelepiped large, medium,
If you can specify the shape by size such as small,
No size data entry is required.

Further, in the above-mentioned embodiment, the size of the shape,
Although the three-dimensional operable range is determined by the data input point B, the reference size of each shape is set in advance as shown in FIG. 10, and the size is input by inputting the magnification for this reference shape. May be changed.

Next, a second embodiment will be described. The present embodiment is an apparatus capable of removing an area where an obstacle exists from a three-dimensional operable area. CPU 20 is shown in FIG.
After the three-dimensional operable range is specified by the procedure shown in FIG. 12, the partial prohibited area setting program shown in FIG. 12 is executed.
In step 300, in the operable range of FIG. 4 displayed on the CRT 27, as shown in FIG. 11, the operator operates the operation panel 26 to display four points S1 on the front surface of the obstacle S on the screen. , S2, S3, S4 are designated. next,
In step 302, the partial prohibited area is calculated from the coordinates of the four input points. This area is determined as an area J sandwiched between the surface G determined by two points and the surface H of the three-dimensional operable area. The partial prohibited area J is defined in the same manner as the three-dimensional operable range shown in FIG. 4 is defined by the position coordinates of the point A and the displacement of the point B on the diagonal with respect to the point. That is, as shown in FIG.
Coordinates _{(S x, S y, S} z) and the displacement e _x, e _y, partial inhibition region J is set by using the e _z.

In the actual positioning control of the tip of the robot, the program shown in FIG. 6 is executed.
In 4, when calculating that the interpolation point at the tip of the robot exists in the three-dimensional movable range, the condition below must not be satisfied.

[Number 1] _{0 ≦ (x-S x /} e x) ≦ 1 and _{0 ≦ (y-S y /} e y) ≦ 1 and _{0 ≦ (z-S z /} e z) ≦ 1

In this way, the area obtained by removing the partial prohibited area from the actual three-dimensional operable range becomes the substantial three-dimensional operable range. If the control target position at the tip of the robot does not exist within this range, the operation is prohibited.

Further, in the case of a sphere, as shown in FIG. 13, when the obstacle S is protruding, the position of the plane V is designated so that the partial prohibited area is flat as shown in FIG. It can be a portion sandwiched between V and the spherical surface Q.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a robot driven by an apparatus according to an embodiment.

FIG. 2 is a block diagram showing an electrical configuration of the apparatus of the embodiment.

FIG. 3 is a flowchart showing a processing procedure by a CPU for setting an operable range.

FIG. 4 is an explanatory diagram showing a method of setting an operable range.

FIG. 5 is an explanatory diagram showing data for specifying an operable range.

FIG. 6 is a flowchart showing a processing procedure of a CPU during positioning control.

FIG. 7 is an explanatory diagram showing another method for setting an operable range.

FIG. 8 is an explanatory diagram showing another method of setting an operable range.

FIG. 9 is an explanatory diagram showing another method for setting an operable range.

FIG. 10 is an explanatory diagram showing another method for setting an operable range.

FIG. 11 is an explanatory diagram illustrating a method of setting a partial prohibited area when an obstacle exists in the operable range.

FIG. 12 is a flowchart showing a calculation procedure by a CPU for setting a partially prohibited area.

FIG. 13 is an explanatory diagram showing a method of setting a partial forbidden area when the operable range has another shape.

[Explanation of symbols]

10 ... Robot main body 18 ... Hand 20 ... Central processing unit 25 ... Memory T ... Tool (welding torch) S ... Displacement sensor W ... Workpiece step 100 ... Shape designating means Step 102-Step 114 ... Position designating means, size designating means Step 116 ... Calculation means Steps 204, 206 ... Judgment means Step 210 ... Operation prohibition means

Claims (4)

[Claims] 1. A robot controller for controlling the position and orientation of a robot, wherein a shape designating means for designating and inputting a shape of the three-dimensional movable range, and a point having a predetermined relationship with the three-dimensional movable range. Is specified in the spatial coordinate system, the position specifying means for specifying the position of the three-dimensional operable range in the spatial coordinate system, and the actual three-dimensional operable range in the spatial coordinate system are specified based on the specified shape. And a calculation means for calculating data for controlling the position and orientation of the robot, the positioning control target position of which is the actual position of the robot at the tip of the robot.
Determining means for determining whether or not the control target position is within the three-dimensional operable range, and positioning control to the control target position if the control target position is not within the actual three-dimensional operable range by the determining means A robot controller provided with an operation prohibiting means for prohibiting the operation. 2. A size designating unit for designating and inputting a value relating to the size of the three-dimensional movable range, wherein the position designating unit or the size designating unit positions the tip of the robot at a predetermined position in a spatial coordinate system. The robot control device according to claim 1, wherein the robot control device is a unit that is moved to, and reads the coordinate value of the point. 3. A partial prohibited area designating means for inputting data for specifying a partial prohibited area in the three-dimensional operable range, wherein the computing means is an area designated by the partial prohibited area designating means. The robot controller according to claim 1, wherein is calculated as a region removed from the actual three-dimensional operable range. 4. A robot controller for controlling the position and orientation of a robot, wherein an operable range designating means for designating and inputting the three-dimensional operable range and a three-dimensional operable range designated by the operable range designating means. In the partial prohibited area designating means for inputting the data for specifying the partial prohibited area, the operation prohibited area designated by the partial prohibited area designating means is designated by the operable range designating means 3.
Calculating means for calculating data for identifying the actual three-dimensional movable range in the spatial coordinate system by removing from the three-dimensional movable range, and the positioning control target position when the position and orientation of the robot are controlled, Part of the reality is 3
Determining means for determining whether or not the control target position is within the three-dimensional operable range, and positioning control to the control target position if the control target position is not within the actual three-dimensional operable range by the determining means A robot controller provided with an operation prohibiting means for prohibiting the operation.