JPH06102919A - Method for teaching robot orbit - Google Patents

Abstract

PURPOSE:To efficiently generate orbit information with less errors by reducing the burden of a user at the time of inputting/editing information on a robot orbit. CONSTITUTION:Shape information on a work, contact point information connecting contact points constituting the edge of the work and robot orbit information are converted into visual images and are displayed in the display device of a computer system. Then, the visual image of robot orbit information which is altered based on an alteration operation designated by the user on the display screen of the display device is displayed. Then, the contact point or a teaching point teaching the orbit of the robot is selected from the display screen, and an approximate curve representating the positions is generated based on the positions of a point group having the preceding/subsequent orders of the contact point or the display point. Then, the altered position is generated on the approximate curve based on the alteration input of the position, and the altered position is displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and system for teaching a robot trajectory, and more particularly to a robot teaching technical field, a robot manipulator control technical field,
Also, it belongs to the field of human interface technology related to human-machine interaction, and specifically, a robot work teaching device (information input interface device) that efficiently conveys to the robot the work that the robot user wants the robot to perform. A method for teaching a used robot trajectory.

More specifically, the present invention relates to an improved method for efficiently generating trajectory information of a general machining operation having a trajectory that conforms to the shape of a target workpiece based on the display of a computer.

[0003]

2. Description of the Related Art Conventionally, there are a direct teaching method, a remote teaching method, an indirect teaching method, and an offline teaching method for teaching position / orientation information in robot trajectory teaching (cited document: "Robot Engineering Handbook", The Robotics Society of Japan). Edited by 1990, published by Corona Publishing Co., pp.519-52
9).

The above-mentioned first conventional direct teach method is a method of directly moving the arm portion of the robot. The above-mentioned second conventional method, the remote teach method, is a method of teaching at a location away from the robot body without directly touching the robot arm with a teaching device called a teaching pendant. In the above-mentioned third conventional method, the indirect teach method, a manipulation arm dedicated to teaching is prepared, and the hand portion of this arm is operated so as to move along a required path. This is a method of teaching by storing. The above-mentioned fourth conventional method, the offline teach method, is a method of teaching away from the actual work environment without using a robot that actually performs the work. in this way,
Since the trajectory of the robot can be generated by using the geometrical shape information of the already shape-designed work, it has an advantage that the burden on the operator can be greatly reduced.

[0005]

However, in any of the above-mentioned first to third conventional methods, the entered trajectory information is first displayed, and in order to carry out the changing work, the trajectory information represented by numerical values is used. It is displayed on the character display device, and the user needs to specify the displayed line and change the numerical value. Therefore, the user has to find a teaching point at a desired position from the information of the teaching point expressed by a numerical value, which has a drawback of compelling the user. In order to correct the teaching point to the desired position / orientation, it is necessary to change the numerical value directly or to retrieve new data of the point again by using the above teaching method, which complicates the operation. Beckoning
This may reduce the efficiency of teaching work.

Further, since the above-mentioned fourth conventional method, the offline teach method, presupposes the geometrical shape information of the work already generated by CAD or the like in the trajectory teaching, the shape information of the work by CAD is used. It is difficult to apply to difficult work.

When the trajectory generated by the off-line teach method is operated in a real work environment, the manipulator,
Errors often occur due to error factors in the actual environment such as jigs and workpieces. In order to reduce the error, measures such as meticulous calibration of the manipulator are taken, but the absolute accuracy driven by the calibration is generally large compared with the repeat accuracy of the manipulator, and actual matching is necessary. The correction of the orbit by matching the actual products requires a complicated operation as in the above direct teach method.

Furthermore, the shorter the update cycle of the manufacturing line to accommodate a new product, the larger the ratio of the drive cost of the robot trajectory teaching becomes, and the efficiency of the trajectory teaching becomes a problem. In addition, editing the trajectory entered first due to the error of the actual environment described above to the final trajectory
The adjustment work occupies a large proportion of the entire trajectory teaching, and the improvement of the human interface in this portion has a great influence.

In addition to the teaching of trajectories, a technique for displaying three-dimensional information represented by trajectories on a two-dimensional display device has been conventionally handled in the field of computer graphics. However, using a 2D device such as a mouse, you can select / move objects that exist in 3D space.
In operations such as modification, only a single object is handled, and there is no technique for operating multiple objects at the same time.

The present invention has been made in view of the above points,
It is an object of the present invention to provide a method for teaching a robot trajectory that solves the above problems, reduces the burden on the user when inputting / editing information related to the robot trajectory, and efficiently generates trajectory information with few errors. To aim.

[0011]

FIG. 1 shows a diagram for explaining the first principle of the present invention.

The present invention is a method for creating a trajectory of a robot by using a computer system having a display device, wherein the shape information of the work and the work among the shape information are stored in the display device of the computer system. The contact point trajectory information connecting the contact points forming the edge of the robot and the robot trajectory information are simultaneously converted into a visual image (step 100).
Display (step 101), and display a visual image of the robot trajectory information edited on the display screen of the display device based on a change operation for the robot trajectory information designated by the user (step 102) (step 103). ,
Select a contact point or a teaching point that teaches the trajectory of the robot from the display screen, and generate an approximate curve representing these positions based on the positions of the contact point or the point group having the order before and after the teaching point ( In step 104, a change input is made to allow the user to input the change amount of the position (step 105), the changed position is generated on the approximate curve based on the changing operation (step 106), and the changed position is displayed. (Step 107).

Further, according to the present invention, the contact point or the teaching point is added immediately before or after the selected point, and the position of the contact point or the teaching point is determined so as to be on the approximate curve.

FIG. 2 shows a second principle explanatory diagram of the present invention.

The present invention is a method for creating a trajectory of a robot using a computer system having a display device, wherein the shape information of the work is stored in the display device of the computer system, and the work is included in the shape information. The contact point trajectory information connecting the contact points forming the edges of the robot and the robot trajectory information are simultaneously converted into visual point images (step 20).
0) is displayed (step 201), and a visual image of the robot trajectory information edited based on the change operation for the robot trajectory information designated by the user on the display screen (step 202) is displayed (step 203), A touch point or a teaching point that teaches the trajectory of the robot is selected from the display screen, a change input of the position / orientation of the robot teaching point is accepted (step 204), and the position / orientation changed by the change input is generated (step 205), it is determined whether or not the changed position / orientation is within the movable area of the robot (step 206), and the determination result is displayed on the display screen (step 207).

[0016]

According to the present invention, an approximate curve representing the positions of a contact point selected from a display screen or a point group before and after a teaching point is generated, and the selected point is moved by constraining it on the approximate curve. By providing a user interface, it is possible to move a point in a three-dimensional space by a two-dimensional or one-dimensional information input device, and when the ideal trajectory for work is a smooth curve, the instruction is given. It is possible to generate a curve that a user generally desires by a single operation without modifying each position / orientation from the taught point group. This facilitates the user's grasp of the three-dimensional space and reduces the burden of point position editing work.

The present invention also provides an additional contact point or
The addition of points in the three-dimensional space is performed in two-dimensional or one-dimensional by generating an approximate curve representing the position of the point group before and after the teaching point, constraining the approximate curve, and determining the position of the added point. 3D information input device
The positioning work in the dimensional space can be greatly simplified, and the position can be specified by a one-dimensional input device for determining the front and rear positions in the approximate curve, and the apparatus can be simplified.

Further, each time the position / orientation of the teaching point is changed, it is determined whether or not the robot can move to the position / orientation of the teaching point, and the validity of the position / orientation is determined. Since the user can know the validity, it is possible to detect a defect before operating the real manipulator, and it is possible to reduce the total trajectory generation operation.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A trajectory teaching method of the present invention will be described below with reference to the drawings.

FIG. 3 shows a computer according to an embodiment of the present invention.
The configuration of the system and robot system is shown. In the figure, the robot system comprises a robot manipulator 1, a sensor fixing jig 2, a laser range scanner 3, and an irradiation laser beam 4, and a computer system 5
Is a display device 6, a keyboard 7, a keyboard connection cable 8, a mouse 9, a mouse connection cable 10, a processing device 1
1, a manipulator / controller 12, and a computer connection cable 13.

Processor 11 of computer system 5
Preferably includes a graphic processor, a storage device, and a central processing unit (not shown), and a workstation is used in this embodiment. A display device 6, a keyboard 7, and a mouse 9 which is a graphic pointing device are connected to the processing device 11. Display device 6
May use a color monitor or a black and white monitor.
The keyboard 7 is preferably a standard computer keyboard and is connected to the processing unit 11 by a keyboard connection cable 8.

Although the mouse 9 is used as the graphic pointing device in the present embodiment, the present invention is not limited to this example, and any graphic pointing device such as a light pen, a touch screen, a trackball, a dial button or the like can be used. May be.

A laser range scanner 3 is connected to the tip of the robot manipulator 1. robot·
The manipulator 1 has an encoder (not shown) for each joint axis.
It is desirable to include. Robot by encoder
The position / orientation of the manipulator 1 can be obtained by kinematic calculation. Robot manipulator 1
By being controlled in the damper mode, the operator can grip the laser range scanner 2 and move the laser range scanner 2 to any position / orientation within the operable range of the robot manipulator 1. The shape of the workpiece 14 on the workpiece table 15 is measured by moving the laser range scanner 2 along the trajectory of the machining operation and irradiating laser light during the movement.

The information indicating the shape of the work 14 obtained by one laser irradiation is called frame information. The position / orientation of the laser range scanner 2 when the laser light is emitted is determined by the value of the encoder included in the robot manipulator 1 at that time. The measured sensor information and the position / orientation information of the laser range scanner 2 are transferred to the computer system 5.

The computer system 5 calculates the position information of the surface of the shape of the work in the world coordinate system by calculating the frame information measured by laser light irradiation and the position / orientation information of the laser range scanner 2. . The positional information on the surface of the work 14 is called a surface model.

In the present invention, the robot manipulator 1 and the laser range scanner 2 are used to obtain the surface model of the work shape. However, in order to realize the present invention, a CAD (Computer Aided Design) system or 3 is used.
Any surface model generator, such as a two-dimensional laser digitizing system, may be utilized to implement the method of the present invention.

The robot manipulator 1 is connected to a manipulator controller 12, and the manipulator controller 12 is a computer system 5.
The robot manipulator 1 is controlled so as to attain the target position / orientation based on the position / orientation target value of the robot transferred from.

Further, in the present embodiment, the robot manipulator 1 is a 6-DOF vertical articulated robot, but any robot manipulator capable of controlling the wrist at a target position / posture can be used. Good.

FIG. 4 is a diagram for explaining the operation of one embodiment of the present invention. A computer display screen 16 is shown in FIG.
Is displayed. The computer display screen 16 includes a main display window 17, a menu bar 18, a pull-down menu 19, a mouse cursor 20, a coordinate icon 21, a tool editing subwindow 23, a frame editing subwindow 24, a shape editing subwindow 25, a selection button 26, and a selection button. A button group 27, frame information 28, a contact point trajectory 29, and a robot trajectory 30 are shown.

In the main display window 17 of the computer display screen 16, a large number of frame information obtained from the target work 14 and a contact point locus 29 connecting the contact points defined in each frame information and the robot are shown. The orbit 30 is displayed. The frame information is composed of observation point groups included in the surface model, and the observation point groups included in this frame information are connected in order. In this embodiment, points constituting the edge of the work 14 in the frame information are contact points, and the contact point locus 29 is displayed by sequentially connecting the contact points.

The surface model of the work 14 is displayed by using any display method such as a plane patch method such as a triangular patch in addition to the display by a plurality of frame information as in the present embodiment. May be.

Next, by clicking on the menu bar 18 with the mouse cursor 20, a pull-down menu 19 is displayed.
Is displayed. The user specifies a command by selecting the command included in the pull-down menu 19 with the mouse cursor 20.

As a method of selecting a command, the present invention may be implemented by using a designation method based on another graphical user interface of the pull-down menu 19 as in this embodiment.

From the above, the command selection method is a so-called graphical interface standard, for example,
The present invention may be implemented using a tool box proposed by Apple Inc. or an OSF / Motif proposed by Open Software Inc.

The selection button group 27 includes a plurality of selection buttons 2.
It is composed of 6. The selection button 26 is used, for example, to specify whether to display frame information or not. In addition to the selection button, any user interface such as a menu dialog box may be used to specify the display on / off.

Next, the operation will be described.

The user is a damper-controlled robot.
The robot manipulator 1 is moved so as to have a manipulator selection unit so that the locus which should be the locus of the contact point on the work 14 is always included in the scanning area of the laser range scanner 3. Regarding the movement of the robot / manipulator 1, the robot / manipulator 1 may be moved on a rough trajectory set by the user.

While the laser range scanner 3 is moving, the work 14 is moved at a constant interval or at a timing specified by the user.
Measure the shape of. The information measured by the laser range scanner 3 at one time is called frame information (not shown). The position / orientation information in the world coordinate system of the laser range scanner 3 at the time when the frame information is measured is generated based on an encoder (not shown) installed in each joint of the robot manipulator 1. This position / orientation information is called robot position / orientation information. The measured frame information and the robot position / orientation information are sequentially transferred to the computer system 5, or the information during movement is stored and collectively transferred to the computer system 5 after the end of exercise.

The computer system 5 converts the frame information into the world coordinate system based on the transferred frame information and the robot position / orientation information, and displays it in the main display window 17 as frame information 28. Main display window 17
The frame group displayed in can be used by the user as shape information representing the shape of the work 14. The frame information 28 includes contact points. The user defines one contact point for each frame information through the user interface, and further displays a chain of contact point information as a contact point trajectory in the main display window 17. For this contact point trajectory, the user inputs the trajectory of the trajectory based on the contact point trajectory using the user interface.

The shape point locus and the trajectory are composed of a shape point and a teaching point, respectively. In the display screen 16, the frame information 28, the shape points, the shape locus 29, the teaching point, the trajectory 30, and the like are selection targets. In this case, the selection is performed by operating the mouse 9 to bring the mouse cursor moving on the screen over the selection target and then clicking the button of the mouse 9. The position / orientation of the selected object is operated by operating the mouse 9. The position / orientation operation may be performed using a multidimensional data input device other than the mouse 9.

When the user selects an object included in the main display window 17, the mouse cursor 2
Move 0 to the display position of the corresponding object, and press the mouse 9
Press the button. In the present embodiment, when the main display window 17 is a trajectory editing window, only objects that represent trajectories such as teaching points, trajectory elements, and trajectories can be selected. To select and operate frame information or shape information, click the frame edit window 24 and shape edit window 25 displayed in the sub-windows with the mouse 9 to call up the main display window 17, respectively. Do the operation.

In the present embodiment, the mouse 9 is operated to select a plurality of point objects such as a plurality of teaching points or action points displayed in the main display window 17 in the menu bar 18. For example, when the menu "Edit" is selected by pressing the mouse button and then the command "Approximation" is clicked in the pull-down menu 19 while the mouse is pressed, the trajectory editing system selects the point cloud in the three-dimensional space. For example, the position is displayed by calculating an approximate curve such as a spline curve using least square approximation, and the position of each point group is displayed by replacing the nearest contact position on the approximate curve.

FIG. 5 shows an input trajectory according to an embodiment of the present invention. A trajectory 30 and a coordinate icon 21 are shown in the main display window 17 of the display screen 16 of FIG. The circle on the track 30 indicates the position of the teaching point. In the figure, since the teaching point is on the approximate curve, it is somewhat lacking in smoothness.

FIG. 6 shows an application example of the approximation operation according to the embodiment of the present invention. This figure is an example in which an approximate operation is applied to the trajectory shown in FIG.

Further, FIG. 7 shows a screen for a teaching point addition operation according to an embodiment of the present invention. In the figure, the main teaching window 17
Includes an additional teaching point 40, an input / output box 41 for position information of the additional teaching point, an up / down button 42, an acceleration type up / down button 43, and a teaching point movement dialog box 4.
There is 4.

To operate this, with the mouse 9 operated, the teaching point displayed in the main display window 17 is selected, and the mouse button is pressed on the menu "Edit" in the menu bar 18. If you select and hold down, click the command such as "Duplicate" in the menu, and select "Add constraint" command from the submenu, the trajectory editing system adds it near the selected display point. At the same time as displaying the teaching point, the teaching point moving dialog box 44 is displayed in the main display window 17.

The user clicks the up / down button 42 with the mouse 9 to input the movement amount into the trajectory editing system. The additional teaching point 40 moves and is displayed according to the input on the approximate curve of the trajectory. The user terminates the operation of the up / down button 42 when he / she finds himself / herself at the optimum position.

FIG. 8 shows an example of display of an error indicating the operable range according to an embodiment of the present invention. In the figure, an error display dialog 44 is displayed in the main display window 17.
In the interface for designating the position of the additional point shown in the present embodiment, or in the operation of changing the position / orientation of the teaching point, the trajectory teaching system uses the kinematics parameter of the designated manipulator every time the changing operation is performed, Check if the manipulator can move to the changed position and orientation of the teaching point. The method of checking the position / orientation uses kinematics known to those skilled in the art.

As a result of checking, when the trajectory teaching system detects that the movement is impossible, the trajectory teaching system displays the error display dialog 44 to the user so that the user can recognize the movement.

FIG. 9 is a flow chart showing a series of operations according to an embodiment of the present invention. Step 90: Obtain frame information from the display screen. Step 91: Obtain position / orientation information of the manipulator at the time of frame information collection. Step 92: Calculate world coordinates of the surface of the shape from the frame information and the robot position / orientation information based on the encoder values. Step 93: Looking at the display screen, select a contact point with the mouse 9. Step 94: Connect the contact points to obtain the contact point trajectory. Step 95: Select the contact point locus with the mouse 9. Step 96: Select a tool model. Step 97: Calculate the trajectory of the manipulator 1 from the contact point trajectory and the tool model. Step 98: It is judged whether or not the manipulator trajectory is within the movable range at the position / orientation changed for each operation of changing the position / orientation of the teaching point. This check is done using kinematic parameters. Step 99: If it is out of the movable range in Step 98, an error display is displayed. Step 100: Allocate to two events (step 101 or step 104) of the trajectory approximation process or the position / orientation information change process. Step 101: Approximate the trajectory. Step 102: If the position / orientation of the manipulator trajectory is within the movable range, the process proceeds to step 100, and if outside the movable range, an error is displayed. Step 104: The position / orientation information changing process of the manipulator 1 is performed. Step 105: It is determined whether the position / orientation of the manipulator trajectory is within the movable range, and if it is within the range, the process proceeds to step 100, and if it is outside the range, an error display is displayed.

[0051]

As described above, according to the present invention, when the user gives a smooth trajectory to the robot, the position of each teaching point of the teaching point group given by teaching is
It is possible to obtain a smooth trajectory as an approximate curve by a single operation instead of correcting the posture, and it is possible to easily generate a smooth trajectory.

When a teaching point is added to an already given trajectory and its position / orientation is to be given correctly,
Also, when trying to correct the position / orientation of the teaching point that has already been taught, the trajectory editing system restricts the position of the teaching point of interest on the approximate curve of the trajectory and changes it, so that the user It is only necessary to specify the front and rear degrees of freedom, and the specification is greatly simplified as compared with the case of specifying all three degrees of freedom of the position.

Since the designated degree of freedom may be one degree of freedom, for example, a two-variable input device such as a mouse can be used for input, and the input device is a mouse, a trackball, or the like.
A degree-of-freedom input device, a one-degree-of-freedom input device such as a dial can be used.

By checking the movable range of the manipulator at the teaching point position input, the input error is reduced,
Moreover, since the error can be noticed without using the actual machine, it is possible to shorten the entire trajectory input time.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the first principle of the present invention.

FIG. 2 is a diagram illustrating a second principle of the present invention.

FIG. 3 is a configuration diagram of a computer system and a robot system according to an embodiment of the present invention.

FIG. 4 is a diagram for explaining the operation of the embodiment of the present invention.

FIG. 5 is a diagram showing an input trajectory according to an embodiment of the present invention.

FIG. 6 is a diagram showing an application example of an approximation operation according to an embodiment of the present invention.

FIG. 7 is a diagram showing a screen for a teaching point addition operation according to an embodiment of the present invention.

FIG. 8 is a diagram showing an example of display of a designation error of an operable range according to an embodiment of the present invention.

FIG. 9 is a flowchart showing a series of operations according to an embodiment of the present invention.

[Explanation of symbols]

 1 Robot Manipulator 2 Sensor Fixture 3 Laser Range Scanner 4 Irradiation Laser Light 5 Computer System 6 Display 7 Keyboard 8 Keyboard Connection Cable 9 Mouse 10 Mouse Connection Cable 11 Processing Device 12 Manipulator Controller 13 Computer Connection Cable 14 Workpiece 15 Machining worktable 16 Computer display screen 17 Main display window 18 Menu bar 19 Pulldown menu 20 Mouse cursor 21 Coordinate icon 23 Tool edit subwindow 24 Frame edit subwindow 25 Shape edit subwindow 26 Select button 27 Select button group 28 Frame information 29 Contact point Trajectory 30 Robot trajectory 40 Additional teaching point 41 Input / output box for position information of additional teaching point 42 Updow Button 43 accelerated up-down buttons 44 taught points move dialog box 45 error display dialog

Claims (3)

[Claims] 1. A method for creating a trajectory of a robot by using a computer system having a display device, comprising the shape information of a workpiece in the display device of the computer system and the shape information among the shape information. The contact point trajectory information connecting the contact points that form the edge of the work and the robot trajectory information are simultaneously converted into a visual image and displayed, and the robot trajectory information specified by the user on the display screen of the display device is changed. A visual image of the robot trajectory information edited based on the operation is displayed, a teaching point that teaches the contact point or the trajectory of the robot is selected from the display screen, and the contact point or the points before and after the teaching point are selected. Based on the positions of the point groups having ranks, an approximate curve representative of those positions is generated, a change input is made to cause the user to input the change amount of the position, and the change input A method for teaching a robot trajectory, which is characterized in that a changed position is generated based on the approximate curve and the changed position is displayed. 2. The contact point or the teaching point is added immediately before or after the selected point, and the position is determined so that the position of the contact point or the teaching point is on the approximate curve. For teaching robot trajectories of robots. 3. A method of creating a trajectory of a robot by using a computer system having a display device, wherein the shape information of a workpiece and the shape information in the display device of the computer system, The contact point trajectory information connecting the contact points forming the edge of the work and the robot trajectory information are simultaneously converted into a visual point image and displayed, and the operation for changing the robot trajectory information specified by the user on the display screen is performed. A visual image of the robot trajectory information edited based on the display is displayed, a teaching point that teaches the contact point or the trajectory of the robot is selected from the display screen, and the position and orientation of the robot teaching point is changed and input. The position / orientation changed by receiving the change input is generated, it is determined whether or not the changed position / orientation is within the movable area of the robot, and the determination result is displayed. A method for teaching a robot trajectory, which is displayed on the display screen.