JP7150211B1 - Painting method and control program - Google Patents

Abstract

a first step of executing a robot control function to move the print head 3 along the surface to be coated and recording robot control signals output while realizing the movement; a second step of performing the desired decoration on the surface to be coated by executing the print control function while executing the robot control function based on the robot control signal, wherein the print control function of the second step includes: The print control signal output to the print head 3 is determined according to the original data determined based on the desired decoration and the correction value determined based on the robot control signal recorded in the first step. be done.

Description

The present invention relates to a painting method for painting a surface to be painted by controlling a multi-axis robot having a print head using a computer, and a control program executed by the computer in the painting method.

In the coating process, a coating device with a print head provided at the tip of a multi-axis robot is used as a coating device that reduces overspray and enables precise drawing. For example, Japanese Patent Application Laid-Open No. 2012-506305 (Patent Document 1) discloses that a multi-axis robot is controlled to guide a print head provided at its tip along a predetermined path of a coating agent to achieve desired coating. It is disclosed to apply Further, Japanese Patent Application Laid-Open No. 2016-221958 (Patent Document 2) discloses applying a desired coating by scanning a print head along a surface of an object to be coated by an arm of a robot.

Japanese Patent Application Publication No. 2012-506305 (or US Patent Application Publication No. 2011/0262622) Japanese Patent Application Laid-Open No. 2016-221958 (or US Patent No. 9452616)

In painting using a print head, when trying to draw a desired figure on a surface to be painted, the movement of the print head and the movement of the print head itself (that is, the movement of the multi-axis robot) are synchronized. It is necessary to let and control. However, in the coating apparatuses of Patent Documents 1 and 2, sufficient consideration has not been given to synchronizing the operation of the multi-axis robot and the operation of the print head. In particular, in order to synchronize the operation of the multi-axis robot and the operation of the print head, it is necessary to calculate the three-dimensional position of the print head and reflect the calculated position on the operation of the print head in real time. Such advanced arithmetic processing was difficult.

Therefore, it is desired to realize a painting method and a control program that can synchronize the operation of the multi-axis robot and the operation of the print head.

A coating method according to the present invention is a coating method for coating a surface to be coated by controlling a multi-axis robot having a print head using a computer, wherein the computer controls each axis of the multi-axis robot. and a print control function of outputting a print control signal for controlling the print head, and moving the print head along the surface to be coated. a first step of executing the robot control function to move and recording the robot control signals output while effecting the movement; and based on the robot control signals recorded in the first step. a second step of performing the desired decoration on the surface to be coated by executing the print control function while executing the robot control function, wherein the print control function of the second step includes: The print control signal output to the print head includes original data determined based on the desired decoration and a correction value determined based on the robot control signal recorded in the first step. , is determined according to

Further, the control program according to the present invention, when executed in a computer, has a robot control function that outputs a robot control signal for controlling each axis of a multi-axis robot having a print head, and controls the print head. a print control function for outputting a print control signal for printing, and a control program capable of executing the robot control function to move the print head along the surface to be coated, and realizing the movement and executing the print control function while executing the robot control function based on the robot control signal recorded in the first mode. and a second mode for performing desired decoration on the surface to be coated. In the print control function of the second mode, the print control signal output to the print head is , the original data determined based on the desired decoration, and the correction value determined based on the robot control signal recorded in the first mode.

According to these configurations, since the correction value used in the print control function when decorating in the second step is determined based on the robot control signal recorded in the preceding first step, the arithmetic processing The motion of the multi-axis robot and the motion of the print head can be synchronized while reducing the load.

Preferred embodiments of the present invention are described below. However, the scope of the present invention is not limited by the preferred embodiments described below.

As one aspect of the coating method according to the present invention, it is preferable that the first step further includes filling the coating target surface with a predetermined paint by executing the print control function.

According to this configuration, the robot control signal used for determining the correction value can be recorded while the coating such as the undercoat is being applied, so the coating efficiency as a whole can be improved.

As one aspect of the coating method according to the present invention, it is preferable that the correction value used in the second step is determined in parallel with the first step.

According to this configuration, since real-time arithmetic processing is not required, the arithmetic processing load can be further reduced.

Further features and advantages of the invention will become clearer from the following description of exemplary and non-limiting embodiments described with reference to the drawings.

1 is a perspective view of a coating device according to an embodiment; FIG. 1 is a perspective perspective view of a print head according to an embodiment; FIG. 1 is a configuration block diagram of a coating apparatus according to an embodiment; FIG. It is a figure which shows the example of desired decoration. It is a figure which shows the example of the decoration which distortion produced. FIG. 11 is a configuration block diagram of a coating apparatus according to a modified example;

An embodiment of a coating method and a control program according to the present invention will be described with reference to the drawings. An example in which the coating method and control program according to the present invention are applied to a coating method for decorating a portion of the surface of an automobile body (hereinafter referred to as a surface to be coated) will be described below.

[Configuration of coating device]
The coating apparatus 1 used in this embodiment has a multi-axis robot 2 with a printhead 3 and a computer 4 capable of controlling the multi-axis robot 2 and the printhead 3 (FIG. 1).

The multi-axis robot 2 is implemented as a six-axis vertical articulated industrial robot. A known robot can be used as the industrial robot. A print head 3 is attached to the tip of the multi-axis robot 2 . The control method of the multi-axis robot 2 can adopt any known control method, for example, each axis pulse method, world coordinate system space coordinate method, user coordinate system space coordinate format, etc. . The following description will be made with the pulse method for each axis in mind.

The operations of the axes X1 to X6 of the multi-axis robot 2 are controlled according to robot control signals, which are control signals output from the computer 4 to the multi-axis robot 2. FIG. Such robot control signals include starting point coordinates (rotation angle), end point coordinates (rotation angle), intermediate point coordinates (rotation angle) set as necessary, and the Parameters such as the speed of attitude change and the shape of the trajectory of the attitude change (linear, circular, etc.) can be included. In this embodiment, a robot controller 21 that directly controls the axes X1 to X6 of the multi-axis robot 2 and acquires pulse counts of the axes X1 to X6 is configured to be able to communicate with the robot controller 21 and the computer 4. Control of each axis X1 to X6 of the multi-axis robot 2 is realized by the PLC 22 and.

The print head 3 is mounted as a known inkjet head, and in the present embodiment, white paint, primer paint, clear paint, and four color paints corresponding to the CMYK color system (cyan (C), magenta (M), yellow (Y), and black (K)) can be individually discharged. Ink may be used instead of paint. More specifically, the print head 3 is provided with seven ejection ports 31 (31a to 31g) corresponding to the seven colors and seven tanks 32 (32a to 32g). Each discharge port 31 is provided with a valve whose opening and closing can be electrically controlled.

Further, an ultraviolet irradiation device 33 is provided adjacent to the ejection port 31 . The ultraviolet irradiation device 33 is configured to irradiate ultraviolet rays having a wavelength capable of curing each paint.

The operation of the print head 3 is controlled according to print control signals, which are control signals output from the computer 4 to the print head 3 . Such print control signals include factors related to ejection from each ejection port 31 (31a to 31g) (for example, a voltage pattern in a piezo ink jet system), the duration of a state in which paint is ejected from each ejection port 31 and a state in which paint is not ejected, can include parameters such as In this embodiment, a print head driver 34 capable of directly controlling each ejection port 31 is provided, and the print head driver 34 controls each ejection port 31 based on a print control signal input from the computer 4. to control the timing at which the paint is discharged from the print head 3 .

[Configuration of computer and control program]
The computer 4 is configured as a computer having a known configuration, and therefore has known computer components and functions such as a CPU, a storage device, and an input/output device. The computer 4 is inputted with the form of decoration (for example, characters, patterns, patterns, etc.) desired to be formed on the surface to be coated.

Computer 4 is electrically connected to multi-axis robot 2 (PLC 22) and printhead 3 (printhead driver 34). A control program according to this embodiment is installed in the computer 4, and the computer 4 has a robot control function for controlling the axes X1 to X6 of the multi-axis robot 2, a print control function for controlling the print head 3, is configured to achieve

In the robot control function, the computer 4 outputs robot control signals that determine the motion of each axis X1 to X6 of the multi-axis robot 2 to the multi-axis robot 2 (PLC 22). The computer 4 can then record the robot control signals during execution of the robot control functions.

In the print control function, a print control signal that determines the operation of each ejection port 31 (31a to 31g) of the print head 3 is output from the computer 4 to the print head 3 (print head driver 34). The print control signal is determined based on the original data determined by the mode of decoration desired to be formed by the operation of the print head 3, but the original data may be corrected. Such correction is performed according to a correction value determined based on the robot control signal. Determining the correction values may be performed as part of the print control function, eg, in parallel with recording robot control signals during execution of the robot control function.

Further, in the print control function, an ultraviolet control signal that determines the operation of the ultraviolet irradiation device 33 of the print head 3 may be output from the computer 4 to the print head 3 (print head driver 34).

[Painting method]
Next, an embodiment of a coating method according to this embodiment will be described. The coating method according to the present embodiment includes a primer coating process, a white coating process, a color coating process, and a clear coating process. Apply paint.

(1) Primer coating process (an example of the first process)
When the primer paint is applied, the print control function is executed to discharge the primer paint from the print head 3 while executing the robot control function to move the print head 3 along the surface to be coated. Specifically, the operation of the discharge port 31b that communicates with the tank 32b that stores the primer paint is controlled. The primer paint is an undercoat, and the entire surface to be painted may be coated with the primer paint (an example of a predetermined paint) (that is, the entire surface to be painted may be coated with the primer paint), There may be some variation in the film thickness of the primer coating on each part of the surface to be coated. Therefore, in the primer coating process, it is sufficient to continuously discharge the primer paint from the print head 3, and it is not necessary to synchronize the operation of the multi-axis robot 2 and the operation of the print head 3. Therefore, in this embodiment, the print control function is executed so that the primer paint is continuously discharged from the print head 3 .

At the same time, robot control signals for the multi-axis robot 2 are recorded. In the primer coating step, the entire surface to be coated is coated with the primer paint, so the multi-axis robot 2 is operated so that the print head 3 sweeps the entire surface to be coated. Therefore, if the robot control signal is recorded from the start to the end of the primer coating process, the robot control signal for realizing the operation of the multi-axis robot 2 necessary to coat the entire surface to be coated is recorded. become. A series of robot control signals recorded at this time specify not only the instantaneous values of the motions of the axes X1 to X6 of the multi-axis robot 2, but also their changes over time. Therefore, the motion of the multi-axis robot 2 is specified in terms of position, velocity and acceleration.

Furthermore, at this time, in parallel, a correction value used in the color painting process, which will be described later, is determined. Specifically, based on robot control signals recorded during the primer coating process, the position, velocity, and acceleration of the print head 3 during coating of the entire surface to be coated are specified, and the print control signals are corrected. Used for value determination. The concept for determining the correction value will be explained in the section on the color painting process.

As described above, the computer 4 executes the robot control function so as to move the print head 3 along the surface to be coated and records the robot control signal. This is an example of mode.

At the same time, the ultraviolet irradiation device 33 is operated to irradiate the primer paint applied to the surface to be coated with ultraviolet rays. Shortly after the primer paint lands on the surface to be coated, it is irradiated with ultraviolet rays to cure the primer paint with ultraviolet rays. The application and curing of the primer coating may be performed simultaneously as described above, but they may also be performed separately. In either case, the robot control function is executed to move the print head 3 along the surface to be coated, while the ultraviolet irradiation device 33 is operated to irradiate the surface to be coated with ultraviolet rays. is executed. This operation is an example of the third mode of the control program according to this embodiment.

(2) White paint process When applying white paint, the robot control function is executed to move the print head 3 along the surface to be painted, while the print control function causes the print head 3 to eject the white paint. is executed. Specifically, the operation of the discharge port 31a communicating with the tank 32a storing the white paint is controlled. As in the primer coating process, even in the white coating process, it is sufficient that the entire surface to be coated is covered with white paint, and there may be some variation in the thickness of the white paint in each part of the surface to be coated. There is no need to synchronize the movement of the axis robot 2 and the movement of the printhead 3 . Therefore, in the white paint process, the print control function is executed so that the white paint is continuously discharged from the print head 3 .

Further, in the primer coating process, the robot control signal is recorded while coating is applied to the entire surface to be coated, so the recorded robot control signal is used in the robot control function in the white coating process. That is, the robot control function of the white coating process is executed based on the robot control signal recorded in the primer coating process. Thereby, the motion (position, speed, and acceleration) of the multi-axis robot 2 in the white coating process can be substantially the same as the motion of the multi-axis robot 2 in the primer coating process.

Note that the robot control signal may be recorded in the white coating process in addition to or instead of the primer coating process. In this case, the white painting step is an example of the first step as well as the primer painting step. If robot control signals are recorded in both the primer coating process and the white coating process, a correction value for the print control signal can be determined based on the robot control signals recorded in both processes. For example, the average value of the robot control signals recorded in both steps can be taken into account in determining the correction value.

In addition, this is similar to the primer coating process in that the ultraviolet irradiation device 33 is operated simultaneously (or separately) with the application of the white paint.

(3) Color painting process (an example of the second process)
When the color paint is applied, the print control function is executed to discharge the color paint from the print head 3 while executing the robot control function to move the print head 3 along the surface to be coated. At this time, the ejection of the four color paints (cyan (C), magenta (M), yellow (Y), and black (K)) is independently controlled, and any color tone can be painted by mixing the colors. Realized.

The robot control signal recorded in the primer coating process is also used in the color coating process. That is, the robot control function of the color coating process is executed based on the robot control signal recorded in the primer coating process. Therefore, the motion (position, velocity, and acceleration) of the multi-axis robot 2 in the color coating process is substantially the same as the motion of the multi-axis robot 2 in the primer coating process. This means that the position, velocity and acceleration of the print head 3 during the full coverage of the surface to be coated in the color coating process reproduces the movement of the print head 3 in the primer coating process.

The print control function in the color coating process is carried out so as to apply desired decorations (for example, characters, designs, patterns, etc.) to the surface to be coated. Specifically, as the original data determined based on the desired decoration aspect, bitmap data expressing the desired decoration in units of dots of four colors is used, and each color based on the bitmap The operation of each ejection port 31 (31d to 31g) corresponding to the paint is controlled.

However, it should be noted that the print head 3 is moved by the operation of the multi-axis robot 2 when the desired decoration is applied to the surface to be coated. For example, between the time the print head 3 reaches a steady speed from a stopped state (section P) and the time the print head 3 moves at the steady speed (section Q), the unit time The distance over which the print head 3 moves is different. Therefore, if the cycle of paint ejection from the print head 3 (generally expressed in units of dpi) is constant, the interval between the paint contact points on the surface to be coated is greater in section P than in section Q. narrow. In this case, the bitmap of the original data cannot be accurately reproduced on the surface to be painted, and the decoration is distorted. For example, when the desired decoration is the figure M shown in FIG. 4 and the difference in the interval between the liquid contact points in the section P and the section Q is not considered, the decoration appearing on the surface to be coated is shown in FIG. It becomes like figure M', and a distortion arises in the edge part corresponding to the area P. FIG.

For accurate color reproduction, it is necessary to match the liquid landing point of each color paint with the liquid landing point corresponding to each dot of the original data. 31g) are separately provided, the trajectory from each ejection port 31 (31d to 31g) to the liquid landing point is different for each color. Therefore, it is necessary to finely adjust the direction of paint ejection for each color paint.

Therefore, in this embodiment, based on the robot control signals recorded during the primer coating process, the position, velocity, and acceleration of the print head 3 during coating of the entire surface to be coated are specified, and these positions, The cycle of paint ejection from the print head 3 is corrected based on at least one of velocity and acceleration. For example, if the paint ejection cycle is increased or decreased based on the speed of the print head 3, the paint landing points on the surface to be coated can be set at equal intervals, and the decoration on the surface to be coated can be reproduced as in the original data. sell. Further, based on the position of the print head 3 and the arrangement of the ejection openings 31 (31d to 31g) in the print head 3, each nozzle is adjusted so that the landing points of the paint ejected from the ejection openings 31 are the same. The ejection direction of the paint from the ejection port 31 can be corrected. In addition, as described above, the determination of the correction value is performed in parallel with the primer coating process.

As described above, the computer 4 executes the robot control function to move the print head 3 along the surface to be coated, while executing the print control function to apply the desired decoration to the surface to be coated. The operation is an example of the second mode of the control program according to this embodiment. Further, the robot control function in the second mode is executed based on the robot control signal recorded in the first mode, and in the print control function in the second mode, the print control signal corresponds to the desired decoration. The original data determined based on and the correction value determined based on the robot control signal recorded in the first mode are also as described above.

As in the primer coating process and the white coating process, the UV irradiation device 33 is operated at the same time (or separately) when each color paint is applied.

(4) Clear painting process When applying clear paint, the robot control function is executed to move the print head 3 along the surface to be painted, while the print control function causes the print head 3 to eject the clear paint. is executed. Specifically, the operation of the discharge port 31c that communicates with the tank 32c that stores the clear paint is controlled. As in the primer coating process and the white coating process, even in the clear coating process, it is sufficient that the entire area of the surface to be coated is covered with the clear paint, and even if there is some variation in the thickness of the clear paint on each part of the surface to be coated. Therefore, the operation of the multi-axis robot 2 and the operation of the print head 3 do not need to be synchronized. Therefore, in the clear paint process, the print control function is executed so that the clear paint is continuously discharged from the print head 3 .

The robot control signal recorded in the primer coating process is also used in the clear coating process. That is, the robot control function of the clear coating process is executed based on the robot control signal recorded in the primer coating process. Therefore, the motion (position, speed, and acceleration) of the multi-axis robot 2 in the clear coating process is substantially the same as the motion of the multi-axis robot 2 in the primer coating process.

It should be noted that this is the same as the primer coating process, the white coating process, and the color coating process in that the ultraviolet irradiation device 33 is operated simultaneously (or separately) when the clear coating is applied. A clear layer that protects the decoration is formed by curing the clear paint with ultraviolet rays.

〔Brief Summary〕
The table below lists the operations of the robot control function and the print control function in each of the steps (1) to (4) above.

[Other embodiments]
Finally, another embodiment of the coating method and control program according to the present invention will be described. It should be noted that the configurations disclosed in the respective embodiments below can also be applied in combination with configurations disclosed in other embodiments unless there is a contradiction.

In the above embodiment, in the primer coating process, the robot control signal is recorded at the same time as the primer coating is applied, and the correction value used in the color coating process is determined based on the robot control signal. However, in the coating method according to the present invention, it is sufficient for the first step to execute the robot control function so as to move the print head along the surface to be coated and to record the robot control signal. The presence or absence is not limited. For example, an operation (so-called idling operation) may be performed in which the print head is moved along the surface to be coated without discharging the paint from the print head, and the robot control signal is recorded during the movement. In addition, in the above embodiment, idle operation may be performed before the primer coating process.

In the above embodiment, the configuration in which the correction value is determined in parallel with the primer coating process has been described as an example. However, in the coating method according to the present invention, the determination of the correction value may be performed at any timing before the start of the second step.

In the above embodiment, the coating method including the primer coating process, the white coating process, the color coating process, and the clear coating process has been described as an example. However, the number and order of steps included in the coating method according to the present invention are not limited to the above configuration, and are appropriately determined according to the type of paint and the order of application that are appropriately selected according to the desired decoration. For example, a configuration in which one or both of the primer coating process and the white coating process do not exist, and a configuration in which the clear coating process does not exist are exemplified. If the surface to be painted is to be decorated directly (applied with color paint) without applying any primer or white paint, the first step is to carry out the dry run described above to determine the correction value. good.

In the above embodiment, no particular reference is made to the movement of the coating device 1 (multi-axis robot 2) and the surface to be coated, but both the coating device 1 and the surface to be coated may be stationary or movable. may be When at least one of the coating device 1 and the surface to be coated is configured to be movable, it is preferable that the correction value is determined taking into consideration the movement. Such directions of movement can be horizontal, vertical, and combinations thereof.

In the above-described embodiment, an example is described in which the surface of the vehicle body of the automobile is the surface to be painted. However, the surfaces to be coated in the coating method according to the present invention include not only the surfaces of automobile bodies, but also the surfaces of structures such as hulls, architectural exterior panels, turbine plates, resin glass, and wheels, as well as walls, ceilings, and floors. It may be a surface, a surface existing indoors or outdoors such as a road surface, and the like.

In the above embodiment, an example of a configuration in which decoration is performed using four color paints corresponding to the CMYK color system has been described. However, in the coating method according to the present invention, the type of paint used for decoration is not particularly limited. For example, as in the example of the color paint above, when decorating with color, the color system of the original data (RGB color system, CMY color system, CMYK color system, Lab color system, L *a*b* color system, grayscale, etc.) may be used. Further, decoration with functional paints such as heat-resistant paints, conductive paints, and antifouling paints may be applied.

In the above embodiment, the control program is installed in the computer 4, and the configuration in which the computer 4 implements the robot control function and the print control function has been described as an example. However, the configuration of the coating apparatus used when carrying out the coating method according to the present invention is not limited to the configuration described above. For example, a configuration in which the computer 4 in the above embodiment is omitted and instead the control program is executed in the PLC 22 (FIG. 6). In this case, a control signal is transmitted from the PLC 22 to each of the ultraviolet irradiation device 33 and the print head driver 34 . In other words, the control of the coating apparatus by using the PLC 22 as an execution subject of the control program also corresponds to "control using a computer" in the present invention.

Regarding other configurations, it should be understood that the embodiments disclosed in this specification are examples in all respects, and that the scope of the present invention is not limited by them. Those skilled in the art will easily understand that modifications can be made as appropriate without departing from the scope of the present invention. Therefore, other embodiments modified without departing from the gist of the present invention are naturally included in the scope of the present invention.

INDUSTRIAL APPLICABILITY The present invention can be used, for example, when decorating a surface to be painted such as an automobile body.

REFERENCE SIGNS LIST 1: Coating device 2: Multi-axis robot 21: Robot controller 3: Print head 31: Discharge port 32: Tank 33: Ultraviolet irradiation device 34: Print head driver 4: Computer

Claims (4)

A coating method for coating a surface to be coated by controlling a multi-axis robot equipped with a print head using a computer,
The computer is capable of executing a robot control function of outputting a robot control signal for controlling each axis of the multi-axis robot and a print control function of outputting a print control signal for controlling the print head. can be,
a first step of performing the robotic control function to move the printhead along the surface to be coated and recording the robotic control signals output while effecting the movement;
a second step of executing the print control function to perform desired decoration on the surface to be coated while executing the robot control function based on the robot control signal recorded in the first step; with
In the print control function of the second step, the print control signal output to the print head includes original data determined based on the desired decoration and the print control signal recorded in the first step. A correction value determined based on the robot control signal and a painting method determined according to. 2. The painting method according to claim 1, wherein said first step further includes filling said surface to be painted with a predetermined paint by executing said print control function. 3. The painting method according to claim 1, wherein the correction value used in the second step is determined in parallel with the first step. A robot control function that, when executed in a computer, outputs robot control signals for controlling each axis of a multi-axis robot having a print head, and a print control that outputs print control signals for controlling said print head. A control program capable of realizing a function,
a first mode of performing the robotic control function to move the printhead along the surface to be coated and recording the robotic control signals output while effecting the movement;
a second mode for executing the print control function to perform desired decoration on the surface to be coated while executing the robot control function based on the robot control signal recorded in the first mode; is possible, and
In the print control function of the second mode, the print control signal output to the print head includes original data determined based on the desired decoration and the print control signal recorded in the first mode. A correction value determined based on the robot control signal and a control program determined according to.

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