JPH0144106B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic painting method and apparatus using a playback type robot.

(Prior Art) In painting using a playback type robot, it is necessary to perform a teaching operation in advance to memorize the movement locus in the robot. This teaching work usually involves the steps of roughly taming the robot's movements, then actually painting the workpiece using those movements, and correcting any areas where problems such as sagging or gaps occur.

Although the above-mentioned teaching work is often criticized as requiring a considerable amount of time, in terms of content, the majority of the teaching work is currently occupied by the above-mentioned correction work. Especially if the shape is complex,
When painting objects with strict quality requirements, such as the body of an automobile, the correction time can sometimes account for more than 90% of the time required for teaching.

This is due to the fact that conventional corrections for sagging, gaps, etc. were based on a method of correcting the operating locus (spraying distance) and speed of the robot. In other words, robots used for painting usually have six operating axes, and in order to carry out the above correction method, the trajectory information and speed regarding all six axes must be corrected at the same time. . Moreover, in order to correct the spray distance, it is virtually impossible to intuitively judge and quantify how much correction is required for each axis, so it is virtually impossible to correct the spray distance using the normal teaching method. It is necessary to repeatedly make corrections by trial and error, and when painting the body of the above-mentioned automobile, which has a complicated movement trajectory, the time required for this correction increases dramatically.

On the other hand, in recent years, attempts have been made to control the amount of paint discharged during robot operation. However, if this paint discharge amount control can be replaced with the above-mentioned trajectory correction work, then at least the painting process can be used to judge by what percentage the discharge amount should be increased or decreased by looking at conditions such as sagging and gaps. This is not difficult for those in the know, and therefore, in this case, a simple numerical correction is sufficient.

However, control of the amount of paint discharge that has been attempted in the past involves outputting multiple on/off signals for paint discharge from the robot control device, which are stored along with the movement locus during robot teaching, and depending on the combination of these signals, two to three levels are output. It is designed to control the discharge amount, so corrections can be made by reading out all of the motion locus information and modifying some of it, or by manually manipulating the discharge amount settings themselves in several stages. It requires a troublesome procedure, and the resolution is too coarse with settings of at most two or three stages, making it an irreplaceable alternative to the trajectory correction described above.

(Object of the Invention) In view of the above-mentioned problems of the prior art, the present invention is capable of continuously changing the amount of paint discharged in robot painting, and does not require special labor when problems such as sagging or gaps occur. It is an object of the present invention to provide an automatic painting method and an apparatus therefor, which can repair the area as quickly as possible without requiring it.

(Structure of the Invention) This purpose is to store information for continuously changing the amount of paint discharged depending on the area to be painted in a state that can be modified independently of the robot's motion trajectory information, and to regenerate the robot. An automatic painting method and device that reproduces and outputs the stored information in chronological order in synchronization with the robot reproduction speed during operation, and corrects the stored information to deal with defects such as dripping and gaps. It is achieved by doing so.

(Example) Hereinafter, an example of the present invention will be described based on the accompanying drawings.

FIG. 1 shows an automatic painting system using a robot according to the present invention. In the same figure, 1 is a painting robot having multiple operating axes;
2 is a paint gun attached to the tip of the arm 1' of the robot 1; 3 is a robot control device; the operation of the robot 1 is feedback-controlled by a control signal 4 of the robot control device 3; ing. However, in this coating system,
In addition to the above configuration, a discharge amount control device 5 is provided which continuously controls the amount of paint discharged depending on the area to be coated.

The discharge amount control device 5 is roughly divided into a control section 6 that stores and outputs paint discharge amount information, and an operation section 7 that actually controls the paint discharge amount. A synchronization signal 8 related to the operating speed of the robot 1 is input from the robot control device 3 to the control section 6, and on the other hand, paint is supplied from the operation section 7 to the paint gun 2 via the paint hose 9. It is becoming more and more common.

The synchronization signal 8 serves as a parameter for the discharge amount control device 5 to store or output information on the discharge amount corresponding to the operation of the robot 1, that is, the part to be painted. The speed at which the stored information is reproduced by the robot control device 3 must be accurately reflected. Here, the synchronization signal 8 is a digital pulse train signal having a frequency proportional to the reproduction speed of stored information of the robot control device 3, which is output over the entire operating period of the robot 1. Note that such signals are often included in the robot control device 3 as internal signals, and can be easily obtained by adding an extraction circuit. However, when using such a signal, the control section 6 in the discharge amount control device 5 receives the synchronization signal 8.
By counting the number of pulses from the start of the operation of the robot 1, it becomes possible to accurately grasp the operation of the robot 1, that is, the area to be painted.

With this configuration, apart from the operation locus information of the robot 1, paint discharge amount information over the entire operating period of the robot 1 is stored in advance in the control section 6 of the discharge amount control device 5. Then, during regeneration operation of the robot 1, the control section 6 controls the robot control device 3.
The synchronization signal 8 is received from the controller and the stored information is outputted in chronological order to the operation unit 7, and the operation unit 7 operates the paint discharge amount based on this, and feeds the paint into the paint hose 9 at a predetermined flow rate. do. As a result, the paint gun 2 discharges a predetermined amount of paint depending on the area to be painted.

Here, if sagging, sagging, etc. occur on the object to be coated and it is necessary to correct it, this can be dealt with by changing the stored information in the control section 6 of the discharge amount control device 5. do.

Hereinafter, the functions of the discharge amount control device 5 will be explained in the second section.
This will be explained in detail based on the figures.

In FIG. 2, 10 is a processing device that controls the flow of signals in the control section 6. Be sure to set the paint discharge amount according to the count number of the synchronization signal 8 in advance by controlling the control unit 5.
This operation is performed by the data input correction device 11. The information input here is written into the memory 12 by the processing device 10.

This memory has stored contents as shown in FIG. 3, for example. In Fig. 3, n, n+1... are memory addresses, C ₁ , C ₂ ... are count numbers, Q ₁ , Q ₂
...represents the discharge amount, respectively. In this example, the discharge amount is Q ₁ from count number C ₁ to C ₂ , and from C ₂ to C ₃
Up to this point indicates that the discharge amount is _Q2 .

Next, during regeneration operation of the robot 1, the processing device 10
is the first count number C ₁ from address n of memory 12
and sets the count number _C1 in the counter 13. The counter 13 counts the number of pulses of the synchronization signal 8 sent from the start of the operation of the robot 1, and issues a signal to the processing device 10 when the number reaches _C1 . In response to this signal, the processing device 10 reads out the information at addresses n+1 and n+2 from the memory 12, outputs the discharge amount _Q1 to the output device 14, and sets the count number _C2 in the counter 13. The counter 13 repeats the above operation until the robot 1 completes its operation.

On the other hand, the output device 14 sends the discharge amount Q ₁ to the operation unit 7, but if the format of the signal required by the operation unit 6 and the format of the signal issued by the processing device 10 are different, it also controls the signal conversion. Doru. Further, the output has a function of holding the same value until new information is input from the processing device 10.

The operating section 7 first converts a signal (usually an electrical signal) from the output device 14 into an air pressure signal. The device for this purpose is an electro-pneumatic converter 15, and an air compressor 16 is connected to this electro-pneumatic converter 15 for supplying a constant source pressure. The output air signal of the electro-pneumatic converter 15 operates the air operator regulator 17 to control the flow rate in the air hose 9, that is, the discharge amount. A paint supply device 18 supplies paint to the air operated regulator 17 at a constant pressure.

Note that regarding the configuration of the operation unit 7, the output device 1
Any type of model may be used as long as the discharge amount can be changed according to the output of 4, but it is preferable to install a part of the operating section 7 inside the painting booth.With the above configuration, at least the air The operator regulator 17 can be installed inside the painting booth.

In this way, due to the existence of the discharge amount control device 5,
In addition to being able to continuously change the amount of paint discharged according to the area to be painted as described above, the amount of paint discharged can also be corrected by changing the operation of the robot 1 by arbitrarily rewriting the amount of discharged Q in the memory 12 of the control unit 6. It can be executed regardless of trajectory information.

Furthermore, it is extremely easy to delete or add a discharge rate change count if a microprocessor is used as the processing device 10, so for example, the discharge rate can be changed only for a part of the area coated with a constant discharge rate. It is also possible to do so.

Furthermore, if a digital memory element is used as the memory 12, the number of bits in each element address determines the resolution of the ejection amount. In other words, since 256 settings are possible with 8 bits, the maximum value of the discharge amount can be set to 500.
If it is about cc/min, continuous control is possible with bits of about 20 c.c./min, and it is also easy to increase the number of bits to further improve the resolution or assign the discharge amount Q to the 2nd address of 8 bits. It is.

Note that the discharge amount control device 5 can be applied to various types of robots. In this case, the modifications required on the robot side are at most the output circuit, waveform shaping circuit,
All you need to do is install a circuit for extracting the synchronization signal, such as a noise prevention circuit.

In addition, the technical idea disclosed by the present invention is not limited to simply correcting sagging and sagging, but can also be used to address various painting defects through control of pattern air, atomized air, electrostatic applied voltage, etc. It can also be applied to adhesive coating, etc.

(Effects of the Invention) As explained above in detail, the present invention provides a discharge amount control device separately and independently from the robot control device, stores in advance paint discharge amount information according to the painting area in this device, and performs robot regeneration. The above-mentioned stored information is reproduced and output in a chronological order during operation.This makes it possible to continuously change the amount of paint discharged depending on the area to be painted, and also to prevent problems such as dripping or sagging. This has the effect of making it possible to arbitrarily and easily modify the robot's motion trajectory information independently of the robot's motion trajectory information.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing an automatic painting system using a robot according to the present invention, Figure 2 is a block diagram showing the internal structure and processing system of the discharge rate control device, and Figure 3 is the inside of the discharge rate control device. FIG. 2 is a schematic diagram showing the state of a storage table of FIG. 1...Robot, 1'...Arm, 2...Painting gun,
3... Robot control device, 5... Discharge amount control device, 8
...Synchronization signal.

Claims (1)

[Scope of Claims] 1 Information for continuously changing the amount of paint discharged according to the area to be painted is stored in advance in a state that can be modified independently of the robot's operation trajectory information, and when the robot is regenerated, An automatic painting method using a robot, characterized in that the stored information is reproduced and output in chronological order in synchronization with the robot reproduction speed, and the stored information is corrected to deal with sagging, sagging, etc. 2. A robot that operates according to movement trajectory information and has an arm with a paint gun attached to its tip, a robot control device that controls robot operation by setting and reproducing stored information, and a continuously variable paint according to the area to be painted. A discharge amount control device capable of storing, modifying, and reproducing information regarding the discharge amount and controlling the paint discharge amount during the robot regeneration operation based on the information reproduction output, the robot control device and the discharge amount control device 1. An automatic painting device using a robot, characterized in that the robot control device and the robot control device are connected to each other by a synchronization signal system that changes in accordance with the reproduction speed of stored information of the robot control device. 3. The automatic painting device using a robot according to claim 2, wherein the synchronization signal is a digital pulse train signal whose frequency changes depending on the speed of reproducing stored information of the robot control device.