JPS6314656B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of controlling a painting robot, which is suitable for automatically painting large objects such as automobile bodies using the painting robot.

Generally, when automatically painting objects that have a large painting area, such as the body of a car,
Conventionally, a method has been widely adopted in which the object to be coated is placed on a conveyor and conveyed, and the painting robot is caused to paint while traveling in the same direction as the conveyance direction of the object.

By the way, in order to transport the painting robot and the object to be painted at the same speed and to perform painting while keeping the relative position between them constant, the operating range of the robot must be made large enough to correspond to the area to be painted. Not necessarily,
The drawback was that the robots became larger. On the other hand, when painting an object whose surface area is larger than the operating range of the robot, it is necessary to perform painting work while displacing the robot relative to the object, which makes it difficult to control. At the same time, there is a drawback that teaching the robot in advance about the details of the painting work becomes extremely troublesome.

The present invention has been made in view of the above-mentioned problems of the prior art, and provides a method for controlling a painting robot in which an object to be painted is divided into a plurality of painting blocks and teaching and playback are performed for each painting block. It is about providing.

In order to solve this problem, the present invention provides a coating robot that paints objects to be coated that are conveyed on a conveyor, a traveling mechanism that causes the coating robot to travel parallel to the conveyor, and a robot that paints objects that are conveyed on a conveyor. a position sensor attached to the conveyor for detecting passage of the object to be coated to a reference position; a pulse generator for generating a pulse signal every time the conveyor moves a predetermined amount; and a relative position of the painting robot with respect to the object to be coated; A method for controlling a painting robot, comprising a control device for controlling the content of painting work such as displacement of joints of the painting robot, discharge of paint, stopping, etc. A process of teaching the content of the painting work for each painting block and storing it in advance in the control device, and at the time of playback, detecting by the position sensor that the object to be coated being conveyed to the conveyor has passed a reference position. and then detecting the position of the object to be coated using a pulse signal from the pulse generator;
After the painting robot faces the first painting block, the traveling mechanism is moved at the same speed and in the same direction as the conveyor to maintain a constant relative position between the painting robot and the object to be coated. a step of performing the painting work based on the teaching stored in the control device; and after finishing painting the first painting block, displacing the painting robot relative to the object to be painted to perform the next painting. The present invention is comprised of a step of displacing the robot to a block, and then a step of causing the robot to paint the next block while maintaining a constant relative position between the robot and the object to be coated. .

With this configuration, the area to be painted on the object to be painted is divided into a plurality of painting blocks according to the operating range of the painting robot, and the content of the painting work is taught for each painting block and stored in advance in the control device. Then, when the robot is operated in playback based on the teaching, the robot performs painting work while maintaining the relative position between the robot and the object to be painted constant in each painting block, and the painting work in one painting block is completed. After that, when moving to the next painting block, the robot only needs to be displaced relative to the object to be painted, so a relatively small robot is required, and teaching can be performed for each painting block, making the teaching work easier. becomes easier.

Embodiments of the present invention will be described below based on the drawings.

First, FIGS. 1 and 2 show a case in which a painting robot is used to paint the body of an automobile. In the figure, 1 is a painting robot, and the painting robot 1 has a base 2, a turntable 3 provided on the base 2, and a first rotatable rotatable upright member on the turntable 3. an arm 4 and a second arm 5 rotatably attached to the upper end of the first arm 4;
, a wrist 6 whose tip end of the second arm 5 is bendable, and a coating machine 7 attached to the wrist 6. The robot 1 is mounted on a traveling carriage 9 installed on rails 8, 8 laid in a pit of a painting booth. The traveling trolley 9 can travel along the rails 8 by means of a traveling drive means (not shown), and the traveling mechanism of the robot 1 is constituted by the traveling trolley 9 and the traveling driving means. be done.

Reference numeral 10 denotes a car body as an object to be coated, and the car body 10 is placed on a trolley 11 and conveyed by conveyors 12, 12.
It is transported along the top in the direction of the arrow in FIG. The painted surface of the car body 10 is divided into a plurality of paint blocks a, b, c, d, and e according to the operating range of the robot 1, and the robot 1 is painted with respect to the car body 10 according to each of the paint blocks a to e. It is now possible to paint by moving it relatively.

FIG. 3 shows a circuit diagram of the control device of the painting robot 1. In the figure, reference numeral 21 denotes a pulse generator that emits a pulse every time the conveyor 12 is transferred by a predetermined amount, and the pulse generator 21 is connected to a gate circuit 22. A position sensor 23 is disposed at a reference position of the conveyor 12 and detects when the vehicle body 10 has passed the reference position.The position sensor 23 is connected to a flip-flop circuit 24. When it passes, a signal is input from the position sensor 23 to the flip-flop circuit 24, which outputs a gate open signal based on the data output of the flip-flop circuit 24, and the gate circuit 22
is configured to open. Then, when the gate circuit 22 is opened, pulses from the pulse generator 21 are momentarily input to the counting circuit 25 via the gate circuit 22, and by counting the number of input pulses, the position of the vehicle body 10 is detected. Next, a potentiometer 26 is attached to the rail 8 and detects the position of the painting robot 1 by changing the voltage.
Reference numeral 7 denotes a potentiometer that is provided at the joints of the robot 1 including the turntable 3, first and second arms 4, 5, wrist 6, etc., and outputs the displacement of each joint as a change in voltage. 2
5. Signals from the potentiometers 26 and 27 are sent to the arithmetic processing unit 2 via an input control device (not shown).
8 to the storage device 29, and this circuit structure can be used to store the teaching contents of the painting work.

On the other hand, in order to read out the painting work contents stored in advance in the storage device 29 and perform a playback operation, the arithmetic processing device 28 starts operating when the vehicle body 10 passes the position sensor 22 according to the control program, While constantly detecting the position of the vehicle body 10 based on pulse signals inputted from the pulse generator 21, the content of the painting work at each position of the vehicle body 10 can be read out from the storage device 29 and output. Among the contents of the painting work, the position of the robot 1 is controlled by driving the traveling drive means of the traveling carriage 9 via a D/A converter 30, a comparator 31, and a servo amplifier 32. In addition, the movements of the robot 1 itself, such as the displacement of the joints of the robot 1, the discharging of paint, and the stopping of the robot 1, are controlled by each actuator that constitutes the operating mechanism of the robot 1 via a D/A converter 33, a comparator 34, and a servo amplifier 35. It is controlled by operating the . The comparators 31 and 34 adjust the operation of the robot 1 by constantly comparing the command content output from the arithmetic processing unit 28 and the actual operation of the robot 1 output from the potentiometers 26 and 27, respectively. This is provided to prevent malfunctions from occurring.

Next, the teaching operation of the painting robot 1 will be explained based on the above-mentioned circuit.

First, the car body 1 to be painted is placed on the conveyor 12.
0 is placed and the vehicle body 10 is transported. and,
When the vehicle body 10 passes the position sensor 23, a gate open signal is inputted from the flip-flop circuit 24 to the gate circuit 22, and a pulse signal from the pulse generator 21 is inputted to the counting circuit 25 every moment. Then, the conveyor 12 is stopped when the vehicle body 10 is at an appropriate position, and the distance of the vehicle body 10 from the reference position at this time is stored in the storage device 29.
Therefore, the traveling carriage 9 is moved and placed in the optimum position for the robot 1 to paint the entire painting block a to be painted first. The position of the robot 1 is detected by the potentiometer 26 and stored in the storage device 29. At this position, a teaching handle is attached to the coating machine 7, and by moving the joints of the robot 1, the robot 1 is taught the coating work of the coating block a. Then, the movement of this joint is converted into a signal by the potentiometer 27, and is stored in the storage device 29 together with the painting information regarding the paint sprayer 7. When the teaching of the content of the painting work on painting block a is completed, a block end mark is input into the storage device 29. By this,
As shown in FIG. 4, data A ₁ consists of information regarding the distance from the reference position of the vehicle body 10 to the painting start position, information regarding the relative position of the robot 1 to the vehicle body 10 at that position, information regarding the movement of joints, paint information, etc. , A ₂ , A ₃ , . . . and a block end mark A _BEM is obtained.

Next, while leaving the vehicle body 10 as it is, the robot 1 is moved in the opposite direction of the arrow in FIG. 1 and stopped at the optimal position for painting the entire painting block b. This relative displacement of the robot 1 with respect to the vehicle body 10 is input from the potentiometer 26 to the storage device 29. Then, at this position, the content of the painting work for painting block B is taught, and then by inputting the block end mark, data group B consisting of data B ₁ , B ₂ , B ₃ , ... and block end mark B _BEM is created. get. In this way, the data groups C, D, and E relating to each painting block c, d, and e are created in sequence, and the teaching work is completed by inputting the end mark END after the last data group E.

Here, a block end mark is input each time the teaching for each painting block is completed, but this indicates that the painting work for only that painting block has been completed, and the teaching information for the next painting block continues. means remembered. On the other hand, the end mark means that all painting of the object to be coated has been completed, and by reading this end mark during the playback operation, reading out all the teaching information is completed.

The playback operation for actually painting the vehicle body 10 based on the teaching information obtained as described above is performed as follows. First, the vehicle body 10 is placed on the conveyor 12, and the vehicle body 10 is conveyed by driving the conveyor 12. And car body 1
When 0 passes the position sensor 23, a signal is sent from the flip-flop circuit 24 to the arithmetic processing unit 28, and reading of data from the storage device 29 is started. At the same time, a pulse signal from the pulse generator 21 is inputted to the arithmetic processing unit 28 every moment, and the arithmetic processing unit 28 constantly detects the position of the vehicle body 10. Therefore, the arithmetic processing unit 28 reads from the storage device 29 information regarding the painting start position of the vehicle body 10 and information regarding the relative position of the robot 1 with respect to the vehicle body 10 at that position, and the D/A
The traveling drive means is operated via the converter 30 and the servo amplifier 32, and the robot 1 is displaced from the right end position in FIG. 1 to the designated position to start painting the painting block a. Robot 1 and vehicle body 1
0, the robot 1 is transported at the same speed as the vehicle body 10 by operating the traveling drive means in synchronization with the pulses from the pulse generator 21. During this time, the arithmetic processing unit 28 Information regarding joint movement, paint discharge, stopping, etc. is output from the robot 1 to the servo amplifier 35 via the D/A converter 33.
The painting block a is painted by making each actuator perform an operation according to the teaching content. When painting of painting block a is completed, the block end mark A _BEM is read out.

When the arithmetic processing unit 28 reads the block end mark A _BEM of the painting block a, it is recognized that the painting work based on the data group A has been completed, and the reading of the painting data B of the painting block b is subsequently started. Therefore, first, information regarding the relative position of the robot 1 with respect to the vehicle body 10 at the painting block b is read out from the storage device 29, and the robot 1 immediately retreats in the direction opposite to the arrow in FIG. 1 and starts painting the painting block b. Move to the specified position to start robot 1 again.
By being transported at the same speed as the vehicle body 10, painting is performed in the painting block b.

In this way, each painted block b, c,
When the arithmetic processing unit 28 reads out the end mark END after painting d and e, the entire painting work on the vehicle body 10 has been completed. Therefore,
The robot 1 is returned to the starting position and waits for the next vehicle body to be painted.

By the way, during the painting work, the drive of the conveyor 12 may be stopped due to a failure or the like. In this case, the traveling of the robot 1 is also stopped at the same time, and the painting of the painting block is completed while maintaining the relative position of the robot 1 and the vehicle body 10. Then, the robot 1 is sequentially moved to relative positions in successive painting blocks with respect to the vehicle body 10, and the painting work is continued until the end mark END is read.
In addition, when moving from one painting block to another painting block, if it becomes impossible for the robot 1 to move to a position relative to the car body 10, the robot 1 will move after the painting work on that one painting block.
When the conveyor 12 starts moving again, the painting operation continues from the succeeding painting blocks to the final painting block.

As described in detail above, according to the method for controlling a painting robot according to the present invention, the painting surface of the object to be painted is divided into a plurality of painting blocks, and teaching and playback operations of the painting work contents are performed for each painting block. Since the coating method is adopted, it is possible to perform painting work on objects having a large painting area using a small-sized painting robot with a relatively small movable range. Furthermore, since teaching can be performed for each painted block, the teaching work is facilitated, and since the teaching content can be corrected individually for each painted block, the correction work can also be easily performed. Furthermore, if there is a partial change in the content of the painting work, all you have to do is re-teach the changed painting block and edit the data by combining this with the data of other painting blocks that have not changed. Since the changed painting work content data can be created, the teaching content can be easily changed.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a painting robot that paints the body of an automobile, FIG. 2 is a right side view of FIG. 1, and FIG. 3 is a specific example of the method for controlling the painting robot according to the present invention. The circuit diagram, FIG. 4, is a diagram showing data stored in the storage device of FIG. 3. 1...Painting robot, 8...Rail, 9...
Traveling trolley, 10... object to be coated, 12... conveyor,
21...Pulse generator, 22...Position sensor, 2
5... Counter, 26, 27... Potentiometer, 28... Arithmetic processing unit, 29... Storage device,
a, b, c, d, e...Painted block, A, B,
C, D, E...data group.

Claims (1)

[Claims] 1. A coating robot that performs coating on an object to be coated conveyed on a conveyor, a traveling mechanism that causes the coating robot to run parallel to the conveyor, and a traveling mechanism attached to the conveyor that allows the object to be coated to pass through a reference position. a position sensor that detects, a pulse generator that generates a pulse signal every time the conveyor moves a predetermined distance, a relative position of the painting robot with respect to the object to be painted, displacement of the joints of the painting robot, and discharge of paint. , a control device for controlling painting work contents such as stopping, and a control device for controlling a painting robot, which divides the painting part of the object to be painted into a plurality of painting blocks, and controls the painting work contents for each painting block. a process of teaching and storing it in the control device in advance; and a process of teaching the workpiece to be conveyed to the conveyor to be memorized in advance in the control device, and detecting that the object to be coated conveyed to the conveyor has passed the reference position by the position sensor, and then applying a pulse signal from the pulse generator to the object to be coated. A step of detecting the position of the object to be coated, and after the painting robot faces the first painting block, the traveling mechanism is caused to travel at the same speed and in the same direction as the conveyor, so that the painting robot and the object to be painted are moved. a step of performing a painting operation based on the teaching stored in the control device while maintaining a constant relative position between the robot and the object to be coated; The process of displacing the robot to the next painting block by relatively displacing the robot to the object to be painted, and then again painting the next painting block while keeping the relative position between the robot and the object to be painted constant. A method for controlling a painting robot, which comprises a process to be performed.