JPH0699378A - Method for teaching robot track - Google Patents

Abstract

PURPOSE:To provide a method for teaching a robot track of efficiently producing track information of small error by reducing a burden as small as possible of a user in the case of inputting the information edited relating to the robot track. CONSTITUTION:Workpiece shape information, tool contact point locus information and robot track information are converted into a visual image and simultaneously displayed (step 1) in a display unit of a computer system, the shape information, contact point locus information and the robot track information having a crossing point in a display picture plane with arbitrarily pointed two points are selected (step 2), and the selected information is displayed by changing its brightness (step 3).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for teaching a robot trajectory, and more particularly to a robot teaching technology field for teaching a robot to work, a robot manipulator control technology field, and human-machine interaction. It belongs to the field of human interface technology. Specifically, the robot work teaching device (information input interface device) is used to efficiently convey the work that the robot user wants the robot to perform to the robot. TECHNICAL FIELD The present invention relates to a method for teaching an improved robot trajectory to efficiently generate trajectory information of a machining operation having a contoured trajectory based on a computer display.

[0002]

2. Description of the Related Art Conventionally, there are a direct teach method, a remote teach method, an indirect teach method, and an offline teach method for teaching position / orientation information as a robot trajectory teaching (cited document: "Robot Engineering Handbook", The Robotics Society of Japan). Ed., Issued by Corona in 1990, pp519-529).

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 making the rules. 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 work whose shape has been already designed, it has an advantage that the burden on the operator can be greatly reduced.

[0004]

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 discover the teaching point at a desired position from the information of the teaching point expressed by a numerical value, which has a disadvantage 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, is premised on the geometrical shape information of the work already generated by CAD or the like in the teaching, C
It is difficult to apply it to a machining operation in which it is difficult to obtain the work shape information by AD.

When the trajectory generated by the off-line teach method is operated in an actual 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 larger than 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 trajectory teaching of the robot becomes, and the efficiency of the trajectory teaching becomes a problem. Due to the above error in the real environment, the editing / adjustment work that edits the first input trajectory into the final trajectory occupies a large proportion of the entire trajectory teaching, and the improvement of the human interface in this part has a large impact. .

In addition to the teaching of trajectories, as a technique for displaying three-dimensional information represented by trajectories on a two-dimensional display device, conventionally, it has been mainly treated in the field of computer graphics. There is. However, in operations such as selection, movement, and modification of objects existing in a three-dimensional space with a two-dimensional device such as a mouse, a single object is handled, and there is no technique for operating a plurality of objects simultaneously.

On the other hand, in the technical field of a two-dimensional graphical user interface, in order to select a plurality of objects at the same time, a combination of a mouse button press and a draw is included in a rectangular area having the press position and the draw position as diagonals. "Rubber band" to select all objects
There is a designation method using a metaphor. This specification method is
If a display device that displays a three-dimensional object in a two-dimensional manner is selected by the "rubber band" metaphor method, a large number of unnecessary objects are included, and there is a problem that usability is poor.

The present invention has been made in view of the above points, and reduces the user's burden as much as possible when inputting / editing the information related to the robot trajectory, and efficiently generates trajectory information with few errors. It is an object to provide a method for teaching a robot trajectory.

[0011]

FIG. 1 shows the principle of the present invention.

According to the present invention, in a method of creating a trajectory of a robot by using a computer system having a display device and a pointing device, work shape information and tool contact point trajectory information are displayed in the display device of the computer system. The robot trajectory information is converted into a visual image and displayed simultaneously (step 1), shape information having two points arbitrarily pointed and intersection points on the display screen, contact point trajectory information,
Robot trajectory information is selected (step 2), and the brightness of the selected information is changed and displayed.

[0013]

According to the present invention, by designating two points on the screen of the display and selecting shape information, contact point trajectory information and robot trajectory information having an intersection with the two points, a display screen as a two-dimensional device is obtained. By using the mouse to specify two points on the screen and selecting and displaying all display objects that have an intersection between the two points and the screen, the user can easily and accurately select multiple objects. You can choose. As a result, a plurality of pieces of information in the three-dimensional space can be selected and edited at the same time, the work of correcting the trajectory is reduced, and the overall operation efficiency for the selected object is improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The trajectory teaching method and system of the present invention will now be described in detail with reference to the drawings.

FIG. 2 shows the configurations of a computer system and a robot system according to an embodiment of the present invention. 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
Display device 6, keyboard 7, keyboard connection cable 8, mouse 9, mouse connection cable 10, processing device 1
1, a manipulator / controller 12, and a computer connection cable 13.

Processing unit 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
Can be implemented using a color monitor or a black and white monitor, as is well known in the art. The keyboard 7 is preferably a standard computer keyboard and is connected to the processing unit 11 by a 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. With the encoder, the position / orientation of the robot manipulator 1 can be obtained by kinematic calculation. The robot manipulator 1 is controlled in the damper mode, so that the operator holds the laser range scanner 3 and moves the laser range scanner 3 to any position / posture within the operable range of the robot manipulator 1. You can The shape of the work 14 on the work table 15 is measured by moving the laser range scanner 3 along the trajectory of the working operation and irradiating the 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 3 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 3 are transferred to the computer system 5.

The computer system 5 calculates the measured frame information and the position / orientation information of the laser range scanner 3 to calculate the work 1 in the world coordinate system.
The position information of the surface having the shape of 4 is calculated. This work 14
The position information of the surface of is called a surface model.

In the present invention, the robot manipulator 1 and the laser range scanner 3 are used in order to obtain the surface model of the shape of the work 14, but the CAD (Computer)
Any surface model generation device such as an Aided Design) system or a three-dimensional laser digitizing system may be used 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 connected to the computer system 5.
The robot manipulator 1 is controlled based on the position / orientation target values of the robot transferred from

In this embodiment, the robot manipulator 1 is a 6-degree-of-freedom vertical articulated robot, but any robot manipulator capable of controlling the wrist at a target position / posture may be used.

FIG. 3 is a diagram for explaining the operation of one embodiment of the present invention.

A computer display screen 16 is displayed in FIG. On this computer display screen 16, a main display window 17, a menu bar 18, a pull-down menu 19, a mouse cursor 20, a coordinate icon 21,
Tool editing sub window 23, frame editing sub window 24, shape editing sub window 25, selection button 26, selection button group 27, frame information 28, contact point trajectory 29, robot trajectory 30, multiple object selection line segment 40, anchor point 41, A multiple object selection line segment designation point 42 is shown.

In the main display window 17 of the display screen 16, a large number of frame information obtained from the target work 14 and a contact trajectory 29 and a robot trajectory 30 connecting the contact points defined in each frame information. 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.

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

As a command selecting method, the present invention may be carried out by utilizing a specification method based on another graphical user interface of the pull-down menu 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 holds the tip of the damper-controlled manipulator so that the laser range scanner 3 always includes a locus to be a contact point locus on the work 14 in the scan area of the laser range scanner 3. Move 1 The laser range scanner 3 measures the shape of the work 14 at regular intervals or at a timing designated by the user while moving. The information measured by the laser range scanner 3 at one time is frame information (not shown)
Call. Encoders (not shown) installed at each joint of the manipulator to obtain position / orientation information in the world coordinate system of the laser range scanner 3 at the time of measuring the frame information.
It is generated based on. 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. Further, the chain of contact point information is displayed in the main display window 17 as a contact point trajectory. With respect to 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. The selection is performed by operating the mouse 9 to bring the mouse cursor 20 moving on the screen over the selection target and then clicking the button of the mouse 9. The position / orientation of the selected target is operated by operating the mouse. The position / orientation operation may be performed using a multidimensional data input device other than a mouse.

When selecting an object included in the main display window 17, the user moves the mouse cursor 20 to the display position of the corresponding object and clicks the button of the mouse 9. In this embodiment, when the main display window 17 is a trajectory editing window, only objects that represent trajectories such as teaching points, trajectory elements, orbits can be selected. When the frame information or the shape information is selected and desired to be operated, the frame information window and the shape editing window respectively displayed in the sub windows are clicked with the mouse 9 to call the main display window 17, and then the operation is performed.

A single object can be selected by an object selecting operation by mouse click. However, when it is desired to select a plurality of objects at the same time, the mouse cursor 20 is moved to a position where there is no object on the screen and the mouse button is clicked. Then, after the position is set as the anchor point 41, the draw operation of moving while clicking the button is performed. During the drawing operation, a line segment connecting the anchor point 41 and the mouse cursor 20 is displayed on the screen.

The user moves the mouse cursor 20 so that a plurality of objects to be selected have an overlapping portion on the screen with the line segment connecting the anchor point 41 and the mouse cursor 20 to a position that is considered appropriate. When the mouse button is released, the position of the mouse cursor at that time is determined as the plural object selection line segment designation point 42.

The plural object selection line segment is thus determined as the line segment connecting the anchor point 41 and the plural object selection line segment designation point. A selectable object having an intersection point on the display screen with the multiple object selection line segment 40 is selected.

If the user wants to select objects other than the object having the intersection with the multiple object selection line segment 40, or wants to deselect some of the selected objects, Open
The discontinuous selection method as shown in the selection model of Chapter 3, Section 3.1 of Toppan, 1991, "OSF / Motif Style Guide Release 1.1" by Software Foundation may be used.

FIG. 4 shows a high level flow chart showing the sequence of operation of one embodiment of the present invention.

The flowchart shown in the figure is an application of the above discontinuous selection method to the present invention.

Step 10: Select the window containing the object to be edited on the display screen.

Step 11: Anchor points are obtained by clicking the mouse 9.

Step 12: Obtain a plurality of object selection line segment designation points.

Step 13: Obtain a plane A perpendicular to the display screen and including the anchor and the designated point.

Step 14: The following steps 15, 16 and 17 are executed for each element to find the element intersecting the plane A.

Step 15: Let a be a value obtained by substituting the starting point on the element into the equation representing the plane A.

Step 16: The following step 17 is performed for each point on the element except the start point.

Step 17: Substitute the points on the element into the equation of the plane, set the value as b, and if axb <0, store it as an element intersecting the plane A.

Step 18: Obtain a plane B which is perpendicular to the plane A and includes the anchor and the designated point.

Step 19: The center of the line segment AB is set to O.

Step 20: The following steps 21 and 22 are executed for each element stored as the intersecting element and the element is returned.

Step 21: Let X be the projection point on B of the intersection of the plane A and the element.

Step 22: If the distance between OA> = the distance between OX, it is returned as an element to be selected. However,
OA is a line segment between the center O and A, and OX is a line segment between the center O and the projection point X.

As described above, according to the present invention, the frame information of the shape of the work 14 is input, the frame information is processed, and the spatial positional relationship of the work 14 is grasped by the contact point trajectory, the trajectory information and the frame information.

Although the workstation and the mouse are used in this embodiment, the invention is not limited to the above example as long as the device satisfies the above requirements.

[0058]

As described above, by applying the method of the present invention, the user can easily input the shape of the work required for trajectory generation in the form of frame information, and only the shape information can be input. Alternatively, information on the direction from the start point to the end point can be simultaneously input in the form of frame order. In addition, since the trajectory of the manipulator is generated based on the frame information, the user can enter the contact point in the measurement area of the laser range scanner at the most, even if the user does not input the robot position accurately. Therefore, it is possible to greatly simplify the user's trajectory teaching.

Further, the user can understand the shape of the work from the frame information displayed on the display screen, and the contact point locus obtained by processing the frame information and the contact point locus are created. It is possible to simultaneously check the three types of orbit information on the display screen while comparing their positions and orientations. As a result, the user can easily understand the spatial positional relationship of the three types of information, and can efficiently create the trajectory information that is the final output information.

Next, in this embodiment, by using a display screen which is a two-dimensional device and a mouse, two points are designated on the screen and all display objects having an intersection between the two points and on the screen are displayed. Since the means for selecting and displaying is provided, the user can easily and accurately select a plurality of objects. This makes it possible to provide a robot teaching device that comprehensively improves the operation efficiency for the selected object.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram of a computer system and a robot system according to an embodiment of the present invention.

FIG. 3 is a diagram for explaining the operation of the embodiment of the present invention.

FIG. 4 is a high level flow chart showing a series of operations of one 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 Processor 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 Multiple object selection line segment 41 Anchor point 42 Multiple objects択線 amount specified point

Claims (1)

[Claims] 1. A method of creating a trajectory of a robot using a computer system having a display device and a pointing device, comprising: a workpiece shape information, a tool contact point trajectory information, and a robot in the display device of the computer system. The trajectory information is converted into a visual image and displayed simultaneously, and the shape information, the contact point trajectory information, and the robot trajectory information that have two arbitrarily pointed points and the intersection on the display screen are selected, and the brightness of the selected information is selected. A method for teaching a robot trajectory, characterized by changing and displaying.