JPH06222828A - Robot sensor detection position teaching method - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a sensor teaching method for a robot, which can teach a sensor operation corresponding to a work without an operator setting a detection position of the sensor offline. [Structure] It is determined based on the information about the welding location determined based on the data from the work data storage section 503, the data from the work environment data storage section 501 and the robot data storage section 505, and the information about the welding location. Information about welding position and sensor operation pattern storage
The sensor operation pattern is selected based on the data from the 505, and the operation simulation of the sensor is performed on the workpiece based on the selected sensor operation pattern in the same way as the actual machine to determine the position of the work location to be detected by the sensor. Then, this is given to the controller of the robot to teach the robot the detection position of the sensor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a teaching / playback method for teaching a detection position of a sensor off-line.

[0002]

2. Description of the Related Art In recent years, due to automation of factories, a welding torch is provided at the tip of an articulated arm in a welding line, and a predetermined welding operation is automatically performed by the welding torch by operating the arm. Welding robots that are used in are used. The welding torch also functions as a sensor that detects the position of the work by detecting the contact with the surface of the work, which is the object to be welded, by a voltage change. As such a welding robot, a teaching / playback type that mainly stores a pre-teached work procedure and executes the welding work according to the stored work procedure is mainly used.

Conventionally, in teaching work for storing work procedures in a welding robot, an operator uses the actual welding robot and the work to move the welding torch along the welding line of the work, and a position where the welding torch passes, An online method was used in which the welding torch posture, welding sequence and welding conditions were stored in the welding robot controller.

However, such a teaching method has a problem in that the teaching work requires an extremely large amount of time and manpower, and the welding line must be stopped during the teaching work. Therefore, a method of teaching the operation of the welding robot by off-run programming that creates an operation program of the welding robot off-line without moving the actual welding robot has come to be performed.

As such an off-line teaching method, there is a method described in Japanese Patent Application Laid-Open No. 62-274307. This method simulates the robot operation based on the robot and work shape data input to the computer, and the operator then positions the welding torch, the posture of the welding torch, and the welding work sequence based on the simulation result. Also, by inputting welding conditions to the computer, the robot sensor operation instruction data is created in the computer, and the teaching operation is performed by inputting this data to the robot controller.

[0006]

By the way, in the above-mentioned conventional offline teaching method, in order to set the detection position of the welding torch with respect to the workpiece, the operator sets the position of the welding torch at each detection position and the posture of the welding torch as described above. Since each of these is input to the computer, the burden of the teaching work of the operator is larger than that of the online teaching method, and there may be a gap between the actual detection position and the taught detection position. Since the deviation is corrected by the online teaching method, there was a problem that the welding line was stopped during that time. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a robot capable of teaching the detection position of the sensor corresponding to the work offline without the operator setting the detection position of the sensor. It is to provide a method for teaching a sensor detection position.

[0007]

According to a method for teaching a sensor detection position of a robot according to the present invention, a robot controller for performing a work by detecting a work place of a target object by a sensor provided in the robot is used for the target object. In a method of teaching a robot a detection position of a sensor by creating in advance a computer with information related to the position of a work location to be detected by the sensor according to the shape of an object, Of the sensor operation pattern, the data on the state of the work site environment, the data on the shape and performance of the robot, and the data on the shape of the object, and the computer causes the data on the state of the work site environment and the shape and performance of the robot. The work postures of the robot and the object are determined based on the Then, the work location is determined based on the data relating to the shape of the object, and the corresponding sensor operation pattern is selected from the plurality of sensor operation patterns based on the determined work posture and the determined work location. And simulating the operation of the sensor to determine the detection position of the sensor based on the selected sensor operation pattern and the determined work posture, and providing the controller of the robot with information on the determined detection position. And

[0008]

In the present invention, a basic sensor operation pattern of the robot stored in advance is given to the computer, and based on the shape of the work place of the object and the work posture of each of the robot and the object in the computer, A corresponding pattern is selected from the given sensor operation patterns, and simulation is performed based on these patterns. In the simulation, the sensor is operated according to the selected pattern with respect to a three-dimensional shape such as a groove shape at a work place of the object, and a detection position to be taught is calculated based on a position where the sensor contacts the object. Therefore, the detection position can be obtained by causing the robot to actually perform the detection operation according to the shape of the work location. Then, the calculated result is taught to the control device of the welding robot. As a result, the operator can teach the detection position of the sensor corresponding to the shape of the object without inputting the sensor detection position.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments thereof. FIG. 1 is a schematic side view of a welding robot system used for implementing a sensor detection position teaching method for a robot according to the present invention (hereinafter referred to as a method of the present invention), in which 1 is a welding robot. The welding robot 1 is provided with an articulated arm 11, and a welding torch 12 that also functions as a sensor is attached to the tip of the arm 11. The welding torch 12 can be moved to any position by the operation of the arm 11. On the front surface of the welding robot 1, a positioner 2 that supports a work 20 that is an object to be welded and that rotates the supported work 20 at an arbitrary angle is provided. In the welding robot system configured as described above, a predetermined welding operation is performed while moving the welding torch 12 with respect to the work 20 rotated and positioned by the positioner 2. The welding work is performed by the teaching method described later.

FIG. 2 is a block diagram showing the configuration of a computer system used to carry out the method of the present invention.
Is a computer that creates teaching data for automatically operating the welding robot system. The computer 3 includes an input device 4 including a keyboard and a mouse for inputting various data, work data described below,
An external storage device 5 that stores various data such as robot data, work environment data, and basic welding condition data, and a display device 6 including a CRT that displays an image are connected, and are created by a computer 3. A robot controller 10 that stores teaching data and controls the welding robot system according to the stored data can be connected.

FIG. 3 is a functional block diagram showing subdivided functions related to teaching data creation in the computer 3, and includes a part related to the external storage device 5. The work data storage unit 501 of the external storage device 5 stores the shapes of equipment (environmental objects) arranged around the welding robot 1 and the positioner 2 at the work site, the welding robot 1 and the positioner 2.
And data relating to the working environment such as the positional relationship between the positioner 2 and the environment. The robot data storage unit 502 stores robot data that is data relating to the welding robot system, such as the shape and performance of the welding robot 1 and the shape and performance of the positioner 2. The work data storage unit 503 stores work data, which is data about the work 20, such as a three-dimensional shape of the work 20 (detailed shape related to the work such as a groove shape) and a designated welding position (position information and welding leg length information). ing. The basic welding condition data storage unit 504 stores data relating to basic welding conditions such as welding current, welding voltage, and weaving in association with the shape of the work 20. In the sensor operation pattern data storage unit 505, data on the basic operation pattern of the welding torch, which is a position detection sensor, such as 1-point 1-axis sensing, 1-point fillet sensing, 2-point groove sensing, etc. Is stored in association with the basic shape and welding posture of the.

The data stored in the work data storage section 503 is given to the welding point discriminating section 307, and the welding point discriminating section 30
Reference numeral 7 denotes a welding position determination unit, which will be described later together with the data given, for determining the detailed shape of the welding location such as the groove shape of the welding location in the work 20 based on the three-dimensional shape of the workpiece 20 and the designated welding location. 306, the sensor operation pattern selection unit 308, and the basic welding condition selection unit 310.

The welding posture determination unit 306 is also given the data stored in the work environment data storage unit 501 and the robot data storage unit 502.
3 of the welding robot 1 and the work 20 based on the positional relationship between the welding robot 1, the positioner 2 and the environment, the shape and the performance of the welding robot 1, the shape and the performance of the positioner 2, the work 20 and the three-dimensional shape of the welding location, etc. Determine the welding position of the dimension. The basic welding condition selection unit 310 is also given the data stored in the basic welding condition data storage unit 504,
The basic welding condition selection unit 310 selects a basic welding condition for the welding point based on the information on the welding point of the work 20.

The determination results of the three-dimensional postures of the welding robot 1 and the work 20 determined by the welding posture determination unit 306 are given to the sensor motion pattern selection unit 308 and the motion simulation unit 311 which performs motion simulation of welding work.
Further, it is given to the basic welding condition correction unit 309 which corrects the basic welding condition selected by the basic welding condition selection unit 310.

The sensor operation pattern selection unit 308 is also given the data stored in the sensor operation pattern data storage unit 505, and the sensor operation pattern selection unit 308 determines the sensor operation pattern based on the welding posture and the welding position of the work 20. The operation simulation unit selects the result of the selection.
Give to 311.

In the basic welding condition correction unit 309, the basic welding conditions selected in the basic welding condition selection unit 310 are used to perform welding based on the data given from the welding posture determination unit 307 and the basic welding condition selection unit 310. A teaching welding condition data storage unit 31 that corrects the welding posture according to the welding posture and stores the correction result as the welding condition in the teaching data.
Give to four.

In the motion simulation unit 311, a sensor motion simulation is performed based on the data given from the welding posture determination unit 306 and the sensor motion pattern selection unit 308, and the welding robot 1 and the positioner 2 other than the sensor part are simulated.
Performs a motion simulation of the equal welding robot system. In the motion simulation other than the sensor part, a motion simulation for detecting the contact of the welding robot 1 with the positioner 2 and the workpiece 20 or the contact of the welding robot 1 with an environmental object is performed, and the result is the teaching data in the teaching data. It is given to the robot position information data storage unit 315 which is stored as position information of the welding robot system.

On the other hand, when the selected sensor operation pattern is obtained as described above in the operation simulation of the welding robot system, the operation simulation section 311 provides the sensor operation command creation section 312 with information related to the selected sensor operation pattern and creates the sensor operation command. The unit 312 creates a sensor operation command based on the given information and gives the created sensor operation command to the operation simulation unit 311. The operation simulation unit 311 performs simulation by checking the interference (contact) between the welding wire of the welding torch and the work as will be described later, according to the operation command from the sensor operation command creation unit 312. Sensor operation command creation unit 312
Stores the contact position between the welding torch or the welding wire at the tip thereof and the work, which is the result of the sensor operation simulation, and gives this to the sensor detection position determination unit 313 which calculates the detection position of the welding position to be taught. The sensor detection position determination unit 313 gives the calculated detection position to the robot position information data storage unit 315.

The welding conditions in the teaching data stored in the teaching welding condition data storage unit 314 and the robot system position information and the welding torch detection position information stored in the robot position information data storage unit 315 are used to determine the robot teaching data. Provided to the unit 316, and the robot teaching data determination unit 31
6 is for determining the teaching data regarding the welding work of the welding robot system and the welding torch based on the data given from the teaching welding condition data storage unit 314 and the robot position information data storage unit 315, and controlling the determined teaching data by the robot control. Transfer to device 10.

Next, a method of determining the sensor detection position by simulation will be described. FIG. 4 is a schematic diagram illustrating an example for explaining the determination of the detection position by the sensor operation simulation, and the sensor operation pattern is single-point fillet sensing. In the figure, 12 is a welding torch that is also a sensor, and 20 is L
It is a work of letter shape. Wires placed on welding torch 12
The origin of the tip of 121 is O, the height direction of the workpiece 20 is the z-axis,
A coordinate system having a y-axis in a direction orthogonal to the side plate of the work 20 is taken. When the sensor operation command storage unit 312 (see FIG. 3) outputs to the operation simulation unit 311 a command to move in the −y direction, the welding torch 12 moves in parallel from the origin O in the −y direction,
The welding wire 121 at the tip of the welding torch 12 contacts the work 20 at the contact position P ₁ and stops. Motion simulation part
311 outputs the position coordinates of the contact position P ₁ to the sensor operation command storage unit 312.

The sensor operation command storage unit 312 includes the welding torch 12
Is output to the operation simulation unit 311 from the contact position P _{1 in the} + y direction for a predetermined length, and when the completion of the retreat is recognized, the sensor operation command storage unit 312 then causes the welding torch 12 to move.
Outputs a command to move in the -z direction to the operation simulation section 311, and the welding torch 12 moves in parallel in the -z direction from the retracted position. Then, the welding wire 121 contacts the contact position P ₂
When it comes into contact with the work 20 and stops, the operation simulation unit 311 outputs the position coordinates of the contact position P ₂ to the sensor operation command storage unit 312.

The sensor operation command storage unit 312 displays the contact position P ₁
And the position coordinates of P ₂ are output to the sensor detection position determination unit 313. Then, the sensor detection position determination unit 313 calculates the vertical intersection of the contact positions P ₁ and P ₂ , and determines the result as the position coordinate of the detection position S. Then, the determined position coordinates of the detection position S are made into teaching data by the robot position information data storage unit 315 and the robot teaching data determination unit 316 as the detection position information of the welding torch 12 together with the position coordinates of the origin O, and this is the robot control device. It is transferred to 10 and the detection position of the sensor is taught.

[0023]

As described above in detail, in the sensor teaching method for the welding robot according to the present invention, the position detected by the sensor is automatically determined and taught offline, so that the teaching work by the operator is unnecessary. The burden on the operator is eliminated and the teaching time is shortened.Since the detection position of the sensor is determined by a simulation of the sensor operation similar to that of the actual machine, there is no deviation between the actual detection position and the teaching position, so there is no welding defect. The present invention has excellent effects such as not occurring.

[Brief description of drawings]

FIG. 1 is a schematic side view of a welding robot system used for carrying out an off-line welding robot sensor teaching method according to the present invention.

FIG. 2 is a block diagram showing the configuration of a computer system used for implementing the method of the present invention.

FIG. 3 is a functional block diagram showing subdivided functions related to teaching data creation in a computer.

FIG. 4 is a schematic diagram illustrating determination of a detection position by a sensor operation simulation.

[Explanation of symbols]

 1 Welding robot 2 Positioner 3 Computer 10 Robot controller 12 Torch 20 Work 308 Sensor motion pattern selection unit 311 Motion simulation unit 312 Sensor motion command generation unit 313 Sensor detection position determination unit 315 Robot position information storage unit 316 Robot teaching data determination unit 501 Work environment data storage unit 502 Robot data storage unit 503 Work data storage unit 505 Sensor operation pattern storage unit

Claims (1)

[Claims] 1. A robot control device for performing work by detecting a work place of an object by a sensor provided in the robot, the position of the work place to be detected by the sensor according to the shape of the object. In a method of teaching a robot a detection position of a sensor by creating and giving such information in advance by a computer, the computer is provided with a plurality of sensor operation patterns of the robot, data on a state of a work site environment, a shape of the robot, and Data regarding performance and data regarding the shape of the object are given, and the computer determines the work postures of the robot and the object based on the data regarding the state of the work site environment and the data regarding the shape and performance of the robot. The work location based on the shape data of the object , A corresponding sensor operation pattern is selected from the plurality of sensor operation patterns based on the determined work attitude and the determined work location, and based on the selected sensor operation pattern and the determined work attitude, A method for teaching a sensor detection position of a robot, which comprises simulating an operation of a sensor to determine a detection position of the sensor, and giving information on the determined detection position to the control device of the robot.