JP3117553B2 - How to set coating conditions for coating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, for example, CAD / CA
The present invention relates to a coating condition setting method which enables setting of coating conditions by computer simulation such as M.

For example, in the automotive industry, for example,
With the increase in the amount of industrial robots introduced in recent years and the diversification of product models, various problems such as difficulty in robot work design and increase in the number of teaching steps have become apparent. At present, as a means for solving these problems, a robot CAD simulation system that performs robot teaching by computer simulation is considered to be promising.

On the other hand, among the above robots, for example, in the case of a painting robot, not only the control of the trajectory of the painting gun with respect to the work but also the control of painting conditions (variables) such as the amount of paint discharged is important. It is necessary that teaching under these coating conditions can be performed accurately.

[0004]

2. Description of the Related Art The introduction of a robot as described above requires a work design of the robot.
This work design of the robot means that after setting the work to be performed by the robot based on the process design, the specifications of the layout, tools, work procedures, peripheral equipment, etc., the operating posture of the robot and the work efficiency (cycle time etc.) This is the work of deciding while evaluating in advance.

[0005] In the study at the time of this work design, since the robot and the work cannot be actually used, the designer must consider the three-dimensional imagination of the complicated motion of the robot in his head. Be strong. Thus, many deficiencies in work design arise from this uncertain imagination.

[0006] As a technique for solving this, robot CAD simulation by a computer has recently been introduced. Robot CAD simulation is a teaching playback method using an actual robot
The teaching using the direct teaching method is performed using a computer. The robot, work, jigs, peripheral equipment, etc. are projected on the CAD display screen and teaching is performed while simulating. The teaching data is downloaded to the actual robot to operate the robot, thereby eliminating uncertain imagination and eliminating deficiencies in application studies.

The robot CAD simulation will be described in more detail by taking an industrial robot for automobiles as an example. First, work data of a body, a bumper, a paint gun, a jig, and the like is created by a computer, and teaching data is created based on the work data while projecting and simulating a robot or the like on a computer display. The created teaching data is checked for interference check, cycle time, etc. in an automatic simulation mode of a computer. If the check result is good, the teaching data is converted and generated into a robot language and downloaded to the actual robot. . The actual robot executes the teaching while confirming the teaching result.

In the robot CAD simulation described above, for example, in a robot system such as a welding robot, it is sufficient to accurately control the trajectory of the robot, that is, to control the positioning accuracy, the tracing accuracy, and the speed.
It is fairly well established and has achieved almost sufficient results.

On the other hand, in a painting robot as disclosed in Japanese Patent Application Laid-Open No. 2-280865, for example, not only control of the trajectory of the painting gun but also control of painting variables for determining the thickness of the paint film after painting are important factors. Therefore, it is not sufficient to simply perform the trajectory control accurately as in the general robot described above. Here, the painting variables are specifically painting conditions such as, for example, a paint discharge amount, a painting electrostatic voltage, and an atomizing pressure.

[0010] In the conventional method, the setting of the coating parameters is performed by a teaching playback method by an actual robot.

In the teaching of the playback type painting robot, first, a locus to be drawn by a painting gun is set in accordance with the shape and position of a part to be painted on an object surface such as a vehicle body, and then the locus is set. The locus data represented is stored in the storage means of the control unit. Further, a large number of teaching points are provided on the set trajectory, and the coating gun is used in order to perform reliable coating so that a good coating film is formed on the surface of the object to be coated such as the vehicle body. The moving speed to be taken at the teaching point, the paint discharge state, the paint discharge direction, and the like are set in advance, and the operation data representing these are stored in the storage means of the control unit. Then, an operation control signal for moving the coating gun in accordance with the trajectory data and the operation data to the coating robot is formed, and a control program including the operation control data is finally set.

After the teaching is performed,
The painting robot is operated in accordance with a control program set by the control unit, moves the attached painting gun to draw a set trajectory, and at each of the teaching points, applies the teaching gun to the painting gun. The movement speed, paint discharge state, paint discharge direction, etc. set for the point are taken,
Paints the car body.

As described above, the teaching for painting by the playback type painting robot is usually performed by using the actual painting robot and the actual vehicle body. At this time, the teaching points are set to be extremely large. The man-hours required for this are significantly increased, and the control program has the ideal form due to various operational or time constraints due to the use of the actual painting robot and the actual vehicle body. There is a problem that setting is difficult. Therefore, in order to cope with such a problem, the teaching method for painting the body of the painting robot also uses the above-described computer simulation method without using the actual painting robot and the actual body. It has been proposed to do so.

However, in the case where teaching for painting the body of the painting robot is performed by using a computer simulation method, a large number of teaching points are provided on a set locus, and each teaching point is provided. Operation control data representing an operation control signal for a coating robot to determine a moving speed, a paint discharge state, a paint discharge direction, and the like at which a good paint film is formed on the vehicle body at the point of the paint gun is formed. Since the evaluation of whether the coating film formed on the vehicle body is good is made based on the finishing condition of the coating on the vehicle body, the coating film formed on the vehicle body has already been proposed. It is generally difficult to reflect the fact that Because, there has been a problem that the control program which is set by the teaching becomes as based on the relatively low accuracy of the motion control data.

Therefore, for example, teaching of a painting robot as described above, which is to perform a painting operation on an object to be painted by moving an attached painting gun so as to draw a predetermined locus, is performed by computer simulation. A control variable for forming operation control data representing an operation control signal for the painting robot at each of the teaching points used when performing the method using the method, calculating the coating efficiency for the object to be coated at the teaching point, There has also been proposed one that is set based on the input variable data for the teaching point and the calculated paint application efficiency.

The coating efficiency represents the ratio of the amount of the paint actually forming the coating film on the object to the amount of the paint discharged from the coating gun to the object to be coated. For example, at least the paint atomization pressure and the paint electrostatic voltage of the paint gun applied to the painting robot were used as variable terms, or the paint from the paint gun was added in addition to these paint atomization pressure and paint electrostatic voltage. And the distance from the coating gun to the object to be coated as a variable term is calculated by a multiple regression analysis technique. In this case, the coating film on the object to be coated refers to a coating layer formed under the condition that the coating material adhered to the object to be dried is dried to exhibit a predetermined shrinkage ratio.

If the control variables set as described above are also based on the input variable data manually input in advance and the paint application efficiency, the operation control data formed based on the control variables However, it is a high-precision thing that properly reflects that the coating film formed on the car body is good,
Therefore, a control program based on highly accurate operation control data for the painting robot is set.

[0018]

However, the above method is
It is assumed that the shape of the surface to be coated is flat. For example, when there is a complicated uneven surface shape such as an engine room or a trunk room of an automobile, it is not possible to set a coating parameter with high accuracy.

That is, as described above, when the coating conditions are set by merely using the coating efficiency as a factor without considering the shape of the surface of the object to be coated, a convex portion or a concave portion is formed on the surface of the object to be coated. If so, there is a problem that the thickness of the coating film cannot be made constant.

[0020]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems, and requires a required coating for each of a plurality of teaching points provided on a coating locus of a coating means. In a method for setting coating conditions of a coating apparatus, in which a coating condition according to a film thickness is set as a factor of a coating efficiency on a workpiece surface, the coating efficiency is obtained from the shape data of the workpiece surface. The coating conditions are set based on the coating efficiency obtained from the shape data.

[0021]

According to the method for setting coating conditions of coating equipment of the present invention,
A coating condition setting method for a coating device in which a coating condition corresponding to a required coating film thickness is set for each teaching point of a plurality of teaching points provided on a coating locus of a coating means, and a coating efficiency is set as a factor. The coating efficiency is determined by the shape data of the surface of the object to be coated, and final coating conditions are set based on the coating efficiency determined by the shape data.

That is, in this method, in addition to data such as coordinates, posture, required coating film thickness, etc., at each teaching point on the above-mentioned painting locus, which is currently input in a human system, data regarding the shape of the coating portion is further added. Input, determine the final coating efficiency based on the input data,
Set the coating conditions.

[0023]

Therefore, according to the method for setting the coating conditions of the coating equipment of the present invention, even if the surface of the object to be coated has irregularities, it is possible to realize a coating film having an appropriate set thickness in consideration of the irregularities.

[0024]

1 to 4 show a coating condition setting method and a coating condition setting system for a coating apparatus according to an embodiment of the present invention.

First, FIG. 2 shows a coating robot apparatus in which teaching is performed using a CAD simulation technique under an application of an example of a method for setting coating conditions (control variables for coating) of the coating robot according to the present invention. 1 shows the configuration.

In FIG. 2, a painting robot 10 of an articulated type and a teaching playback system is set on a robot transport conveyor 12, and the painting robot 10
Is provided with a base portion 14, a movable arm portion 16 supported by the base portion 14, and a movable wrist portion 18 connected to a distal end portion of the movable arm portion 16. Is provided, and a control unit in the robot that causes each unit to perform an operation based on the operation control signal is built in. In addition, the movable wrist unit 1
8 is provided with a coating gun 20.

The coating gun 20 performs, for example, electrostatic coating. The coating gun 20 is supplied with a high voltage for electrostatic coating from a voltage generator 22 and
The control air for controlling the switching of the coating pattern through the first air passage 25 provided with the coating pattern switching control valve 24 and the second air passage 27 provided with the coating atomization pressure switching control valve 26 are provided. Control air for controlling the switching of the paint atomization pressure is supplied. The paint color selected by the paint color selection unit 30 is supplied through a paint passage 35 provided with an on-off valve 32 and a discharge amount control unit 34, respectively. Control air for controlling the switching of the amount of paint discharged from the paint gun 20 through a third air passage 29 provided with a control valve 28 is supplied.

Further, a robot control unit 40 for the painting robot 10 is provided. When the painting robot 10 performs painting, the robot control unit 40 first opens and closes the on-off valve 32 provided in the paint passage 35. An operation control signal Sa for performing the opening / closing control for the operation, an operation control signal Sp to the coating pattern switching control valve 24, a control signal Sv to the voltage generation unit 22, and an operation control signal Sc to the paint discharge amount switching control valve 28. Further, an operation control signal Sq is supplied to the paint atomization pressure switching control valve 26, and an operation control signal SX is supplied to a control unit in the robot built in the base 14 of the coating robot 10.
The on-off valve 32, the paint pattern switching control valve 24, the voltage generator 22, the paint discharge amount switching control valve 28, the paint atomizing pressure switching control valve 26, and the robot built in the base 14 of the painting robot 10. Each of the operation control signals Sa, Sp, Sv, Ac, Sq and SX respectively supplied to the internal control unit is set by teaching using a computer simulation method for the painting robot 10, and will be described later in detail at the time of such teaching. An example of the method of setting the control variables of the painting robot according to the present invention is applied.

FIG. 1 shows a teaching / playback system for performing teaching using a computer simulation method for a painting robot 10 to which an example of a method for setting control variables of a painting robot according to the present invention is applied. The teaching / playback system includes the robot control unit 40 described above.

That is, in the teaching / playback system of the present embodiment shown in FIG. , A control variable setting unit 57, and a painting robot simulation device 61. As shown in FIG. 3, the CAD / CAM device 51 is provided with a coating surface of various workpieces such as an automobile body to be coated by the coating gun 20 mounted on the coating robot 10. Trajectory data representing the outer shape is set and stored in advance. The control variable setting unit 57 includes a paint application efficiency calculation unit 58, a coating speed / time setting unit 59, and a coating condition setting unit 60.

Under the circumstances, when teaching using the computer simulation method for the painting robot 10 is performed, first, the data selection unit 5 is used.
3 is operated in accordance with the workpiece to be coated shown in FIG.
/ CAM device 51. And CAD / CAM
In the device 51, the image data and the trajectory data are searched according to the data selection signal CL from the data selection unit 53, and the image data DI and the trajectory data DO for the workpiece to be painted set as the painting target are selected. Then, the selected image data DI and locus data DO are supplied from the CAD / CAM device 51 to the control variable setting unit 57.

The data input unit 55, which has been manually input in advance, is output-operated, and the data input unit 55 inputs the locus data DO to the control variable setting unit 57 on the locus of FIG. To non-coordinate data IDP (X) for setting each of a plurality of teaching points.
· YZ) are sequentially input, and for each of a plurality of teaching points No1 to Non, posture data IDA (α, α) indicating the posture to be taken by the coating gun 20.
β, γ), paint execution / stop data (painting ON / OFF data) IDC indicating whether paint should be discharged from the painting gun 20, a teaching point immediately before the teaching point, and the teaching point , Interpolation pattern data IDL indicating the vertical width of the coating pattern on the object to be coated, coating pattern width data IDW indicating the horizontal width of the coating pattern on the object to be coated. A paint electrostatic voltage data IDV representing the paint electrostatic voltage at the paint gun 20, a paint gun distance data IDD representing a distance from the paint gun 20 to the workpiece, a required paint film thickness data IDR representing a required paint film thickness, The shape code data IDF representing the irregular shape of the coating surface of the workpiece to be coated is entered. It is.

The control variable setting section 57 receives the coordinate data IDP and the attitude data ID from the data input section 55.
A, Painting execution / stop data IDC and interpolation format data I
DI is supplied to the painting robot simulation apparatus as coordinate data DP, posture data DA, painting execution / stop data DC, and interpolation format data DI, respectively. Further, in the control variable setting section 57, the coating condition setting section 60 sets the locus data D based on the required coating film thickness data IDR.
Each teaching point (No1 to Non) represented by the coordinate data IDP on the locus represented by O
, A paint pattern control variable indicating a paint pattern on a workpiece to be coated, a paint electrostatic voltage control variable indicating a paint electrostatic voltage in the paint gun 20, a paint discharge control variable indicating a paint discharge amount from the paint gun 20, and , Paint gun 2
A paint atomization pressure control variable indicating a paint atomization pressure at 0 is set, and paint pattern data representing the set paint pattern control variable, paint electrostatic voltage control variable, paint discharge amount control variable, and paint atomization pressure control variable, respectively. DPP, paint electrostatic voltage data DVV, paint discharge amount data DCC, and paint atomization pressure data DQQ are set and supplied to the painting robot simulation device 61.

In the control variable setting section 57, the paint application efficiency calculating section 58 calculates the respective teaching points (No1 to Non) represented by the coordinate data IDP on the locus represented by the locus data DO. The paint application efficiency Pμ is calculated. This paint application efficiency Pμ
Is the amount of paint that actually forms a coating film on the painted surface of the work to be coated with respect to the amount of paint that is discharged from the coating gun 20 to the work to be coated at each teaching point (No1 to Non). The coating film on the surface of the object to be coated here is a coating layer formed under the condition that the paint adhered to the surface of the object to be dried is dried to exhibit a predetermined shrinkage ratio, That is, it refers to the finished paint layer.

The calculation of the paint application efficiency Pμ for each of the teaching points No1 to Non in FIG. 3 by the paint application efficiency calculation section 58 in the control variable setting section 57 is based on the paint set in the coating condition setting section 60. The atomization pressure data DQQ, the paint discharge amount data DCC, the paint static voltage data DVV, the paint part shape code data IDF and the paint gun distance data IDD from the data input unit 55 are used as variable terms, and are calculated by a method of multiple regression analysis. You. Specifically, for example, the paint atomization pressure Qq (g / cm ² ) at the paint gun 20 represented by the paint atomization pressure data DQQ and the paint discharge amount from the paint gun 20 represented by the paint discharge data DCC are represented by Cc ( cc / min), the coating electrostatic voltage Vv (KV) of the coating gun 20 represented by the coating electrostatic voltage data DVV, the distance from the coating gun 20 represented by the coating gun distance data IDD to the object to be coated is Dd (mm), and the shape of the coating part. Assuming that the calculation correction coefficient corresponding to the code is M, the paint application efficiency P with the paint static voltage Vv of the paint gun 20 being 0 to 60 KV.
μ (painting efficiency Pμa) is as follows: Pμa = −K1 · Qq + K2 · Cc + K3 · Vv−K4 · Dd + K5 (where K1, K2, K3, K4 and K5 are constants) (1) In addition, the paint application efficiency Pμ when the coating electrostatic voltage Vv of the coating gun 20 is 60 to 90 KV is represented by Pμb = (− K6 · Qq + K7 · Cc + K8 · Vv−K9 · Dd + K10) × M (where K6, K7, K8, K9, and K10 are constants)... (2)

According to an example of the experimental results, the constants K1 to K5 in the above equation (1) are as follows: K1 = 0.00313095 K2 = 0.00002380 K3 = 0.576665200 K4 = 0.02725000 K5 = 43.48620,000 And the constants K6 to K10 in the above equation (2)
K6 = 0.00574375 K7 = 0.01593750 K8 = 0.306620400 K9 = 0.0313330 K10 = 65.593800000

Further, in the control variable setting section 57, the coating speed / time setting section 59 sets the paint application efficiency Pμ5
5, the paint pattern vertical width data IDL, the paint pattern horizontal width data IDW, the paint electrostatic voltage IDV, the paint gun distance data IDD, and the required paint film thickness data IDR, and are calculated by the paint application efficiency calculating unit 58 as described above. Based on the paint application efficiency Pμ, the teaching points No1 to Non represented by the coordinate data IDP on the locus represented by the locus data DO,
Time required for a predetermined volume of paint to be discharged from the paint gun 20, that is, a paint time control variable Tg indicating paint time.
And a coating gun speed control variable Vg indicating the moving speed of the coating gun 20 are converted into the optimum coating film thickness for obtaining the required coating film thickness represented by the required coating film thickness data IDR on the object at each teaching point. Set as things.
That is, the coating time control variable Tg and the coating gun speed control variable Vg relating to the coating gun 20 for each of the teaching points No1 to Non are further added to the input data from the data input unit 55 by the paint application efficiency calculation unit. 58
Is set in consideration of the paint application efficiency Pμ including the correction based on the shape data calculated in.

The setting of the coating time control variable Tg and the coating gun speed control variable Vg is performed, for example, according to the following relational expression.

Tg = Km [γd · Rp · {BL · BW + LW (BL · cos θ +
BW · sin θ)}] / Pμ · NV · γW · Up Vg = LW / Tg where γd is the specific gravity of the paint when dried, γW is the specific gravity of the paint when liquid, Rp is the required coating film thickness, BL and BW is the vertical width and the horizontal width of the coating pattern, and θ is the center axis AL of the rectangle abc which is the coating pattern set at a predetermined teaching point (Pn) on the locus of the coating gun 20 shown in FIG. A rectangle a'-b'- which is a paint pattern actually formed at the teaching point (Pn)
The angle between c′-d ′ and the central axis AL ′, NV is the volume shrinkage when the paint changes from a liquid state to a dry state,
Up is the discharge amount of paint, LW is the travel distance of the coating gun 20 from the teaching point (Pn- ₁ ) immediately before the teaching point (Pn) to the teaching point (Pn) as shown in FIG. Is an operation constant.

The coating speed / time setting unit 59 includes a coating gun speed data DSS representing the set coating gun speed control variable Vg and a set coating time control variable Tg.
Is set, and these are supplied to the painting robot simulation device 61.

As described above, when the control variable setting section 57 sets various control variables related to the painting gun 20 for each teaching point represented by the coordinate data IDP on the locus represented by the locus data DO, The paint application efficiency calculation unit 58 calculates the paint application efficiency Pμ in this manner, and then the paint speed / time setting unit 59 uses the paint gun speed control variable Vg indicating the moving speed of the paint gun 20 and the paint gun 20. From the data input unit 55, the coating pattern vertical width data IDL, the coating pattern width data IDW, the coating static The voltage data IDV, the coating gun distance data IDD, the required coating film thickness data IDR, and the control variable setting unit 57 Paint application efficiency P calculated in
In the setting based on μ, the method for setting the painting robot control variables according to the present invention is applied.

On the other hand, the painting robot simulation device 61 includes the coordinate data DP, the posture data DA, and the painting execution / stop data D supplied from the control variable setting section 57.
C, interpolation format data DI. Painting pattern data DPP,
The coating gun 20 is moved with respect to the object to be coated with respect to the coating robot 10 based on the coating static voltage data DVV, the coating amount data DCC, the coating atomization pressure data DQQ, the coating gun speed data DSS, and the coating time data DTT. Simultaneously, a simulation of a painting operation to be performed by discharging the paint from the painting gun 20 is performed. In the process, the coordinate data D from the control variable setting unit 57 is obtained.
P, posture data DA, paint execution / stop data DVV, paint discharge amount data DCC, paint atomization pressure data DQQ, paint gun speed data DSS, and paint time DTT are modified as necessary. At the end of the simulation, coordinate data corresponding to coordinate data DP, posture data DA, paint execution / stop data DVV, paint discharge amount data DCC, paint atomization pressure data DQQ, paint gun speed data DSS, and paint time DTT, respectively. DXP, attitude data DXA, paint execution / stop data DXC, interpolation format data DXI, paint pattern data DXPP, paint static voltage data DXVV, paint discharge amount DXCC, paint atomization pressure data DXQQ, paint gun speed data DXSS, and paint time data Get DXTT and new control data DXX
And finally make them into the robot control unit 4
Supply 0.

The robot control unit 40 stores the respective data supplied from the painting robot simulation device 61, forms an operation control signal Sa based on the painting execution / stop data DXC, and forms the painting pattern data DXPP. , An operation control signal Sv based on the paint static voltage data DXVV, and an operation control signal Sc based on the paint discharge amount data DXCC.
And an operation control signal Sq is formed based on the paint atomization pressure data DXQQ.
P, attitude data DXA, interpolation format data DXI, coating gun speed data DXSS, and control data DXX to form an operation control signal SX, which is provided by an on-off valve provided in connection with the coating robot 10 of FIG. 32, a coating pattern switching control valve 24, a voltage generating unit 22, a paint discharge amount switching control valve 28, a paint atomizing pressure switching control valve 26, and an operation of appropriately supplying the control unit in the robot built in the base 14 of the coating robot 10. Set the control program appropriately.

As is apparent from the above description, according to the method for setting the control variables of the coating robot according to the present invention, the object to be coated is moved by moving the mounted coating gun so as to draw a previously set trajectory. When using a computer simulation method to teach a painting robot that is to perform painting work on the robot, a control variable for forming operation control data representing an operation control signal for the painting robot at each teaching point, The paint application efficiency, which represents the ratio of the amount of paint actually forming a coating film on the object to the amount of paint discharged from the application gun to the object at the teaching point, is determined by the shape of the surface of the object. Is calculated corresponding to
By being accurately set based on the input variable data for the teaching point and the calculated paint application efficiency, the operation control data formed based on the control variables can be applied to an object to be coated such as a vehicle engine room. It is a high-precision film that appropriately reflects that the coating film formed on the surface is good. Therefore, a control program based on highly accurate operation control data for the painting robot is set.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a teaching system for performing teaching using a computer simulation method for a painting robot to which an example of a method for setting a painting robot control variable according to the present invention is applied.

FIG. 2 is a schematic configuration diagram showing an example of a configuration of a painting robot in which teaching is performed by using a computer simulation method under the application of the above-described example of a method for setting a painting robot control variable according to the present invention. It is.

FIG. 3 is an explanatory diagram showing a movement locus of a coating gun in an example of a method for setting a coating condition of a coating device according to the present invention.

FIG. 4 is a conceptual diagram for explaining a main part of an example of a method for setting a control variable of a coating robot according to the present invention applied to the teaching system shown in FIG. 1;

[Explanation of symbols]

10 is a painting robot, 14 is a base, 20 is a painting gun, 2
2 is a voltage generator, 24 is a paint pattern switching control valve, 26
Is a paint atomization pressure switching control valve, 28 is a paint discharge amount switching control valve, 30 is a paint color selection unit, 32 is an on-off valve, 40 is a robot control unit, 51 is a CAD / CAM device, 53 is a data selection unit, 55 Denotes a data input unit, 57 denotes a control variable setting unit, 58 denotes a paint application efficiency calculating unit, 59 denotes a coating speed / time setting unit, and 60 denotes a coating condition setting unit.

Claims (1)

(57) [Claims] 1. A coating condition corresponding to a required coating film thickness is set for each of a plurality of teaching points provided on a coating locus of a coating means as a factor with respect to a coating efficiency on a workpiece surface. In the method for setting the coating conditions of the coating equipment, the coating efficiency is determined by the shape data of the surface of the workpiece, and the coating conditions are set based on the coating efficiency determined by the shape data. A method for setting coating conditions for coating equipment, characterized by the following.