Painting robot

Abstract

[Summary] [Problem] To provide a painting robot which is capable of improving painting quality even if there is a flaw in a painting area. [Solution] A painting robot 10 comprises: a painting head unit 50 provided with a painting head 53; a robot arm R1 which causes the painting head unit 50 to move to a desired position; a 3D scanner 150 for acquiring 3D painting data of a painting area which has been painted by the painting head 53; and a control unit for controlling operation of the painting head 53 and the robot arm R1 on the basis of 3D image data sent from the 3D scanner 150, wherein the control unit implements additional painting control when it is determined from the 3D painting data that there is a painting defect region PD2, and, in the additional painting control, control is performed to eject paint droplets from the painting head 53 onto the painting defect region PD2 while the painting head 53 is moved so that a nozzle 54 which produced the painting defect region PD2 is moved to a different position.

Description

[Technical Field]

[0001] The present invention relates to a painting robot.[Background Art]

[0002] Robot painting employing robots has become the norm on painting lines for painting vehicles such as automobiles. For example, Patent Document 1 describes the following configuration as an exemplary configuration relating to robot painting. Patent Document 1 discloses technology relating to a painting robot wherein nozzle ejection defects are determined on the basis of a test pattern having multiple check lines.[Prior Art Documents][Patent Documents]

[0003] [Patent Document 1] JP 2023-009853 A[Summary of the Invention][Problems to be Solved by the Invention]

[0004] In the configuration disclosed in Patent Document 1, the nozzle ejection defects can be determined on the basis of the test pattern. However, there is no description at all of a means for improving painting quality to a defined painting quality if a predetermined painting quality is not met because there is a flaw, etc. in the painting.

[0005] The present invention has been devised in light of this situation, and the objective thereof lies in providing a painting robot which is capable of improving painting quality even if there is a flaw in a painting area.[Means for Solving the Problems]

[0006] In order to solve the problems above, a first aspect of the present invention provides a painting robot for painting a predetermined area of a vehicle, the painting robot comprising: a painting head unit provided with a painting head comprising a plurality of nozzles for ejecting paint droplets: a robot arm which has the painting head unit mounted on a tip end thereof and causes the painting head unit to move to a desired position; a 3D scanner for acquiring 3D painting data of a painting area which has been painted by the painting head; and a control unit for controlling operation of the painting head and the robot arm on the basis of 3D image data sent from the 3D scanner, characterized in that the control unit implements additional painting control when it is determined from the 3D painting data that there is a painting defect region, which is a painting defect produced when the previous painting path was formed, and, in the additional painting control, control is performed to eject paint droplets from the painting head onto the painting defect region while the painting head is moved so that the nozzle which produced the painting defect region is moved to a different position.[Effects of the Invention]

[0007] The present invention makes it possible to provide a painting robot which is capable of improving painting quality even if there is a flaw in a painting area.[Brief Description of the Drawings]

[0008] [Fig. 1] is a schematic configuration diagram showing the overall configuration of a painting robot according to an embodiment of the present invention. [Fig. 2] shows a schematic configuration of a painting system comprising the painting robot shown in fig. 1. [Fig. 3] shows a state in which a nozzle-forming face of a painting head unit of the painting robot shown in fig. 1, from which paint is ejected, is seen from a front face. [Fig. 4] is a plan view showing the configuration of the nozzle-forming face of another painting head unit different from the painting head unit shown in fig. 3. [Fig. 5] shows a flow relating to control during painting by the painting robot shown in fig. 1. [Fig. 6] shows a situation, as seen from above, when a vehicle is being painted by a painting head of the painting robot shown in fig. 1. [Fig. 7] shows a cross section of 3D data in a painting area. [Fig. 8] shows a state in which there are continuous painting defect regions in a specific area of a painting path. [Embodiment of the Invention]

[0009] A painting robot 10 according to an embodiment of the present invention will be described below with reference to the drawings. It should be noted that in the following description, the X direction is a longitudinal direction of a nozzle-forming face 52 (painting head 53), the X1 side is the right-hand side of fig. 3, and the X2 side is the left-hand side of fig. 3, as required. Furthermore, the Y direction is a short-side direction (width direction) of the nozzle-forming face 52 (painting head 53), the Y1 side is the upper side of the page in fig. 3, and the Y2 side is the lower side of the page in fig. 3.(1. Outline of painting robot 10)

[0010] The painting robot 10 of this embodiment serves to perform "painting" of an object being painted, which is a vehicle or a vehicle part (a vehicle part constituting a portion of the vehicle will also be described as a vehicle below) positioned on a painting line in an automobile manufacturing plant, and the purpose of the painting robot is to form a paint film on a surface of the object being painted in order to protect the surface and impart an attractive appearance. Vehicles moving along the painting line at predetermined time intervals therefore need to be painted with a desired painting quality in a fixed time.

[0011] Furthermore, the painting robot 10 according to this embodiment is capable not only of forming the paint film, but also of forming various types of designs and images on the object being painted, namely a vehicle or a vehicle part. It should be noted that the object being painted is not limited to a vehicle or a vehicle part, provided that it is a component that needs painting, such as various types of components other than automotive components (e.g., external components for aircraft and railroads), etc.(1-1. Overall configuration of painting system 1 and painting robot 10)

[0012] Fig. 1 is a schematic configuration diagram showing the overall configuration of the painting robot 10 according to an embodiment of the present invention. Fig. 2 shows a schematic configuration of the painting system 1 comprising the painting robot 10 shown in fig. 1. As shown in fig. 2, the painting system 1 comprises the painting robot 10 and an image processor 200.(1-2. Painting robot 10)

[0013] As shown in fig. 1, the painting robot 10 comprises a robot main body 20 and a painting head unit 50 as its main components. The painting robot 10 shown in fig. 1 is depicted as a 6-axis vertical articulated robot by way of example, but the painting robot 10 may be a robot of any type, such as a vertical articulated robot having a different number of axes to 6, a horizontal articulated robot, or an orthogonal robot.(1-3. Robot main body 20)

[0014] As shown in fig. 1, the robot main body 20 comprises, as its main components: a stand 21, first to sixth rotary shafts 22a-22f, a leg portion 23, a first pivot arm 24, a second pivot arm 25, a rotating arm 26, a wrist portion 27, and motors M1-M6 for driving the above components. It should be noted that the parts from the leg portion 23 to the wrist portion 27 correspond to a robot arm R1, but parts other than these such as the stand 21 may also correspond to the robot arm R1.

[0015] Among these, the stand 21 is a part which is installed at a point of installation such as a floor surface, but the stand 21 may equally be capable of travel in relation to the point of installation. Furthermore, the leg portion 23 is a part standing upright from the stand 21, and is provided so as to be rotatable in relation to the stand 21 via the first rotary shaft 22a by means of driving of the motor M1 (see fig. 2). Note that the leg portion 23 may equally be configured not to rotate in relation to the stand 21.

[0016] Furthermore, the first pivot arm 24 is provided at an upper end of the leg portion 23 so as to be pivotable via the second rotary shaft 22b by means of driving of the motor M2. The second pivot arm 25 is further provided on a tip end side of the first pivot arm 24 so as to be pivotable via the third rotary shaft 22c by means of driving of the motor M3.

[0017] The rotating arm 26 is furthermore provided on a tip end side of the second pivot arm 25 so as to be rotatable about the second pivot arm 25. The rotating arm 26 is rotatable via the fourth rotary shaft 22d by means of driving of the motor M4. The wrist portion 27 is furthermore provided on a tip end side of the rotating arm 26. The wrist portion 27 is capable of rotational movement about a shaft portion having a plurality of (such as two) different orientations, for example, by means of driving of the motor M5 and the motor M6. The rotary shafts enabling this rotational movement are the fifth rotary shaft 22e and the sixth rotary shaft 22f, respectively, in fig. 1. This enables the orientation of the painting head unit 50 to be controlled very accurately. Note that there may be any number of shaft portions provided that there are at least two.

[0018] Furthermore, the painting head unit 50 is mounted on the wrist portion 27, but the painting head unit 50 may also be detachably provided on the wrist portion 27.(1-4. Paint supply unit 40)

[0019] The painting system 1 and the painting robot 10 are provided with a paint supply unit 40, as shown in fig. 2. The paint supply unit 40 is a part for supplying paint toward the painting head unit 50. To this end, the paint supply unit 40 comprises: a supply line 41 for supplying the paint from a paint storage portion which is not depicted; a pump which is not depicted; valves, etc. which are not depicted; and a return flow path 42 for recovering paint which has not been ejected.

[0020] It should be noted that when a configuration is adopted where the paint is supplied from outside the painting robot 10, the painting robot 10 need not comprise a part for storing the paint, and the part for storing the paint may be provided outside the painting robot 10.(1-5. Painting head unit 50)

[0021] The painting head unit 50 will be described next. Fig. 3 shows a state in which the nozzle-forming face 52 of the painting head unit 50, from which paint is ejected, is seen from a front face. As shown in fig. 3, the painting head unit 50 comprises a head cover (not depicted), and various components including the painting head 53 are built into the head cover. Moreover, the painting head 53 is provided with numerous nozzles 54 for ejecting paint.

[0022] As shown in fig. 3, openings of the plural ity of nozzles 54 are exposed on the face (nozzle-forming face 52) of the painting head 53 on the side from which paint is ejected. Note that the openings of the nozzles 54 will also be referred to as the nozzles 54 in the description below.

[0023] Furthermore, a plurality of nozzle rows 55 comprising nozzles 54 extending in a direction inclined in relation to a longitudinal direction of the painting head unit 50 are provided on the nozzle-forming face 52. In this embodiment, the nozzle rows 55 are provided with: first nozzle rows 55A which are present on one side (Y2 side) in a main scanning direction (Y direction); and second nozzle rows 55B which are present on another side (Y1 side) in the main scanning direction.

[0024] It should be noted that drive timing of the nozzles 54 is controlled when paint is ejected so that droplets ejected from nozzles 54 in the second nozzle rows 55B land between droplets ejected from adjacent nozzles 54 in the first nozzle rows 55A. This makes it possible to increase the density of dots during painting.

[0025] Furthermore, in the configuration shown in fig. 3, the arrangement of the nozzles 54 in the first nozzle rows 55A and the arrangement of the nozzles 54 in the second nozzle rows 55B are inclined in relation to the short-side direction (Y direction; main scanning direction) of the painting head 53. Such an arrangement of nozzles 54 need not be adopted, however. For example, the nozzle rows 55 may equally be arranged to lie along the short-side direction (Y direction) of the painting head 53. Furthermore, the nozzle rows 55 may constitute one nozzle row 55, without being divided into the first nozzle rows 55A and the second nozzle rows 55B, or may be divided into three or more nozzle rows in the short-side direction (Y direction; main scanning direction) of the painting head 53.

[0026] A flow path for circulating paint (not depicted) is provided inside the painting head 53. Furthermore, a nozzle pressurization chamber (not depicted) is provided inside the painting head 53, and a piezoelectric substrate 62 (see fig. 2) for causing paint to be ejected from the nozzles 54 by changing the volume of the nozzle pressurization chamber is disposed on any wall surface of the nozzle pressurization chamber. The piezoelectric substrate 62 expands and contracts as a result of an external voltage being applied to the piezoelectric substrate 62, and the volume of the nozzle pressurization chamber changes to enable paint to be ejected from the nozzles 54.

[0027] It should be noted that the painting head 53 is not limited to the configuration shown in fig. 3. As shown in fig. 4, for example, the nozzle rows 55 may be formed by arranging a plurality of nozzles 54 side-by-side along the short-side direction (width direction; Y direction) of the painting head 53. Furthermore, when a vehicle CP1 (see fig. 6) is painted using a painting head 53 such as shown in fig. 4, painting may be performed in a state in which the longitudinal direction of the painting head 53 is slightly inclined in relation to the main scanning direction of the painting head 53.

[0028] For example, if the nozzle rows 55 are assumed to be inclined by a predetermined angle α in relation to the main scanning direction in the configuration of the painting head 53 shown in fig. 3, the long-side direction of the painting head 53 should be inclined by the predetermined angle α in relation to the main scanning direction of the painting head 53. This inclination makes it possible to perform painting comparable with that of the painting head 53 shown in fig. 3 simply by adjusting the timing of ejecting paint from the nozzles 54.(1-6. Control configuration of painting system 1)

[0029] The control configuration for controlling operation of the painting system 1 will be described next. Note that the control configuration described below corresponds to the control unit. As shown in fig. 2, the painting robot 10 comprises: a robot arm control unit 70, a paint supply control unit 80, a head control unit 90, a main control unit 100, a scanner control unit 110, a determination unit 120, a position sensor 130, an inclination sensor 140, and a 3D scanner 150. Furthermore, the painting robot 10 is connected to the image processor 200 to thereby construct the painting system 1. However, the painting robot 10 may have the functions of the image processor 200.

[0030] Moreover, the robot arm control unit 70, paint supply control unit 80, head control unit 90, main control unit 100, scanner control unit 110, determination unit 120, and an image processing unit 210 which will be described later are configured from a central processing unit (CPU), a memory such as a storage area (read only memory (ROM) and random access memory (RAM), or non-volatile memory, etc.), and other components. Moreover, the image processing unit 210 may employ a graphics processing unit (GPU) instead of or as well as a CPU which has excellent image processing performance.

[0031] Furthermore, the painting robot 10 may also comprise various types of sensors which are not depicted, with output from these sensors being input to any of the robot arm control unit 70, paint supply control unit 80, head control unit 90, and main control unit 100. Examples of the various types of sensors which may be cited include the abovementioned position sensor 130, inclination sensor 140, and 3D scanner 150, and also include an acceleration sensor, an angular velocity sensor, and an image sensor, but other types of sensors may also be used.

[0032] Here, the robot arm control unit 70 is a part for controlling driving of the motors M1-M6. The robot arm control unit 70 comprises a memory 71 which stores programs and data created by robot teaching.

[0033] The robot arm control unit 70 controls driving of the motors M1-M6 on the basis of the programs and data stored in the memory 71, and image processing by the image processing unit 210 of the image processor 200. By means of this control, the painting head unit 50 can be made to pass, at a predetermined speed, through a desired position for performing painting, and to stop at a predetermined position.

[0034] The memory 71 stores data relating to the trajectory of the painting head 53 (trajectory data), and attitude data relating to the attitude of the painting head 53 such as inclination, created by means of robot teaching which takes account of the painting width which can be painted by the painting head 53. It should be noted that the memory 71 is provided in the painting robot 10, but the memory 71 may also be external to the painting robot 10, and information may be sent / received to / from this memory 71 via a wired or wireless communication means.

[0035] Furthermore, the paint supply control unit 80 is a part for controlling the supply of paint to the painting head unit 50, and specifically controls the operation of the pump and valves, etc. provided in the paint supply unit 40. It should be noted that the paint supply control unit 80 preferably controls the operation of the pump and valves so that the paint is supplied at a constant pressure to the painting head unit 50 from which the paint is supplied.

[0036] Furthermore, the head control unit 90 is a part for controlling operation of the piezoelectric substrate 62 inside the painting head unit 50 on the basis of image processing by the image processing unit 210. When a predetermined position in the trajectory data has been reached according to the means for detecting position, such as the position sensor 130 and inclination sensor 140 which will be described later, the head control unit 90 controls ejection of paint on the basis of split painting data corresponding to the position and a painting path PS1 (see fig. 6). It should be noted that in order to achieve a uniform film thickness in a painting area PD1 (see fig. 6 and 7) in this case, the number of dots (number of droplets) ejected from the nozzles 54 is controlled by controlling a drive frequency of the piezoelectric substrate 62, and the size of the droplets ejected from the nozzles 54 is controlled by controlling an amount of deformation of the piezoelectric substrate 62 on the basis of the drive frequency and / or voltage applied to the piezoelectric substrate 62.

[0037] When the droplet size is controlled by controlling the amount of deformation of the piezoelectric substrate 62 on the basis of the drive frequency applied to the piezoelectric substrate 62, the maximum droplet size is achieved by driving the piezoelectric substrate 62 at a drive frequency matching the natural frequency of the piezoelectric substrate 62. It is therefore possible to control the droplets to a smaller size as the drive frequency applied deviates further from the natural frequency. Furthermore, when the droplet size is controlled by controlling the amount of deformation of the piezoelectric substrate 62 on the basis of the voltage applied to the piezoelectric substrate 62, it is possible to control the droplets to a larger size the higher the voltage applied to the piezoelectric substrate 62.

[0038] The main control unit 100 is a part for sending predetermined control signals to the robot arm control unit 70, the paint supply control unit 80, and the head control unit 90 so that the motors M1-M6, the paint supply unit 40 and the piezoelectric substrate 62 collaborate to paint the object being painted.

[0039] The scanner control unit 110 controls operation of the 3D scanner 150. The main control unit 100, for example, may be used instead of the scanner control unit 110, within the control unit constituting the control configuration of the painting robot 10.

[0040] The determination unit 120 is a part which determines whether or not there is a painting defect region PD2 such as will be described later, based on the result of a measurement by the 3D scanner 150. It should be noted that the determination unit 120 may be functionally realized within the control unit constituting the control configuration of the painting robot 10, but if there is a single 3D sensor unit which can be externally fitted with the 3D scanner 150, then the determination unit may be functionally realized within this 3D sensor unit. Furthermore, the determination unit 120 is a part which makes a determination on the basis of 3D data, but the determination unit 120 may also be functionally realized within the image processor 200, which is a part that performs this kind of image processing.

[0041] Furthermore, the position sensor 130 is a sensor for detecting the current position of the painting head 53. A rotary encoder, a resolver, a laser sensor or various other types of sensor may be used as this position sensor 130. Furthermore, the inclination sensor 140 is a sensor for detecting the angle of inclination of the painting head 53. A gyro sensor, an acceleration sensor, or various other types of sensor may be used as this inclination sensor 140, for example.

[0042] Furthermore, the painting robot 10 comprises the 3D scanner 150. The 3D scanner 150 is a sensor which is also capable of acquiring height (thickness) data in addition to acquiring planar 2D data. A LiDAR scanner, a laser scanner, and photogrammetry, etc. may be cited as such a 3D scanner 150.

[0043] The 3D scanner 150 is mounted on the painting head unit 50, for example. The robot arm R1 is therefore actuated when 3D data of the painting area PD1 (described later) is to be acquired. However, the 3D scanner 150 may be provided separately from the painting head unit 50. As an example of such a configuration, the 3D scanner 150 may be provided on a predetermined part of the robot arm R1 which is separate from the painting head unit 50. Furthermore, it is also possible to adopt a configuration in which a dedicated arm for mounting the 3D scanner 150 on the painting robot 10 is provided, the 3D scanner 150 being mounted on this arm.

[0044] Furthermore, the painting system 1 is provided with the image processor 200. The image processor 200 comprises the image processing unit 210 and a memory 220. The image processing unit 210 is a part for creating image data for each painting path PS1 constituting the pathway on which the painting head 53 performs painting.

[0045] Furthermore, the memory 220 is a part for storing the image data for each painting path PS1 correspondingly with a painting sequence.

[0046] It should be noted that a computer, for example, corresponds to the image processor 200, and this computer may be a component forming part of the painting robot 10 or may be provided separately from the painting robot 10. When the image processor 200 is provided separately from the painting robot 10, data is sent and received between the image processor 200 and the painting robot 10 by means of wired communication or wireless communication. It should be noted that even if the image processor 200 is provided separately from the painting robot 10, the image processor may be included in the concept of the painting robot 10 or may not be included in the concept of the painting robot 10.(2. Control during painting)

[0047] The control during painting using the painting system 1 and painting robot 10 having the configuration above will be described next with reference to the flowchart in fig. 5. Fig. 6 shows a situation, as seen from above, when a vehicle is being painted by means of the painting head 53. Painting is first of all performed as shown in fig. 6 (step S01). When this painting is performed, the robot arm control unit 70 controls, under a command from the main control unit 100, driving of the motors M1-M6 on the basis of the programs and data stored in the memory 71, and image processing by the image processing unit 210 of the image processor 200. By means of this control, the painting head unit 50 can be made to pass, at a predetermined speed, through a desired position for performing painting, and to stop at a predetermined position.

[0048] Furthermore, when the painting is performed, the head control unit 90 causes driving of the piezoelectric substrate 62 under a command from the main control unit 100 so that paint is ejected onto the object being painted, and paint droplets are ejected from the nozzles 54. Painting is thus performed on a painting path PS1 having a predetermined width by causing ejection of paint droplets while the painting head 53 is moving. Painting is then performed on all of the painting paths PS1, and painting of the painting region is completed.

[0049] After the painting has been performed as described above, the robot arm control unit 70 actuates the robot arm R1 under a command from the main control unit 100, while the scanner control unit 110 also actuates the 3D scanner 150. The painting area PD1 is then scanned, and 3D data of the painting area PD1 is acquired (step S02). At this point, 3D data such as shown in fig. 7 is acquired, for example. Fig. 7 shows a cross section of 3D data in the painting area PD1. In fig. 7, a thickness D1 is the defined painting thickness. Note that the thickness D1 is a painting thickness threshold which needs to be cleared. That is to say, a painting area PD1 where the thickness D1 is not achieved corresponds to a painting defect region. Note that, in the following description, an area where there is a painting defect will be referred to as a "painting defect region PD2". A painting defect region PD2 should not have reached the thickness D1, and therefore corresponds not only to an area where the painting film thickness does not reach the thickness D1, but also to a part where painting has been missed. Moreover, a painting defect region PD2 may have a different tone when viewed from the outside, such as looking whitish in that part only.

[0050] Moreover, the position of a defective nozzle 54 in the sub-scanning direction does not change in the painting head 53. This means that there are continuous painting defect regions PD2 at a specific position in the width direction of the painting path PS1, as shown in fig. 8.

[0051] Here, when a configuration is adopted where the 3D scanner 150 is mounted on the painting head unit 50 as described above, the 3D scanner 150 may scan (i.e., acquire 3D data of) areas downstream, in the main scanning direction, from the area where droplets from the painting head 53 landed. In this case, when a painting path having a predetermined width has been formed by droplets landing from the painting head 53, it is possible to acquire 3D data using the 3D scanner 150 within the same painting path as said painting path which was formed.

[0052] The determination unit 120 then determines whether or not there is a painting defect region PD2 in the painting area PD1, based on the 3D data acquired (step S03). If it is judged from this determination that there is no painting defect region PD2 ("No"), then the series of processes is terminated.

[0053] If there is judged to be a painting defect region PD2 in step S03 ("Yes"), then position information of the painting defect region PD2 is acquired (step S04). Information relating to the extent to which the threshold thickness D1 has not been reached is preferably acquired at this time.

[0054] It is feasible here that the cause of formation of a painting defect region PD2 not reaching the thickness D1, as described above, is that a nozzle 54 has become clogged or that there is some kind of problem with the piezoelectric substrate 62. Accordingly, there is a risk that this painting defect will not be eliminated if control is performed so that droplets are ejected from the same nozzle 54 as the nozzle 54 which formed the defective region.

[0055] Therefore, based on the 3D data of the painting area PD1 measured by the 3D scanner 150, the main control unit 100 shifts the position of the painting head 53 so that the defective nozzle 54 does not scan the painting defect region PD2 again (step S05). This shift in position may be produced by simply rotating the painting head 53 to move it to a different position from the position where the defective nozzle 54 scanned the painting defect region PD2. Furthermore, the painting head 53 may be moved by a predetermined amount in a direction intersecting the main scanning direction (e.g., the sub-scanning direction) to thereby move it to a different position from the position where the defective nozzle 54 scanned the painting defect region PD2.

[0056] It should be noted that the process in step S05 is preferably based on position information of the painting defect region PD2 acquired in step S04 to ensure that the defective nozzle 54 does not scan the painting defect region PD2.

[0057] After the position of the painting head 53 has been shifted in this way, additional painting control is implemented to eject paint droplets onto the painting defect region PD2 (step S06). In the additional painting control, the painting thickness after painting has been performed is assumed to have reached the defined thickness D1. It should be noted that when painting is performed on the outward path of the painting head 53, for example, this additional painting control may be implemented on the return path, or may be implemented on a dedicated painting path, regardless of whether this is the outward path or return path of painting.

[0058] After this painting has been performed, the processing of step S02 and onward is once again implemented. At this time, the 3D scanner 150 preferably performs a scan only of the area previously judged to include the painting defect region PD2, in order to improve painting productivity.

[0059] Performing painting in this way achieves a state in which there are no painting defect regions PD2.(3. Variant examples)

[0060] An embodiment of the present invention was described above, but the present invention may be modified in various ways in addition to this embodiment. Variant examples will be described below.

[0061] It is possible to adopt a configuration in which the 3D scanner 150 described above is provided separately from the painting robot 10. For example, it is possible to adopt a configuration in which the 3D scanner 150 is provided separately from the painting robot 10 by installing the 3D scanner 150 on a wall surface, etc. of the painting line.

[0062] Furthermore, in terms of the painting system 1, the 3D scanner 150 may be mounted on an arm tip end of a dedicated robot (termed an inspection robot) for moving the 3D scanner 150, rather than it being mounted on the painting robot 10, and the painting area PD1 may be scanned by the 3D scanner using this robot.

[0063] With such a configuration, the inspection robot on which the 3D scanner 150 is mounted may be actuated at the same time as painting is performed by the painting robot 10. Therefore, when a painting path having a predetermined width has been formed by droplets landing from the painting head 53, it is possible to acquire 3D data using the 3D scanner 150 within the same painting path as said painting path which was formed.

[0064] Furthermore, when the 3D scanner 150 is incorporated into the painting system 1, the 3D scanner may be configured in any way, provided that it is capable of acquiring 3D data. For example, in the case of a configuration enabling acquisition of 3D data by combining multiple normal cameras capable of acquiring 2D data, this combination of multiple cameras corresponds to the 3D scanner 150 as referred to in the present invention.

[0065] Furthermore, the 3D scanner 150 may be used not only for scanning painting areas PD1 which have been painted, but also for other purposes. For example, when there is no CAD data for a vehicle or vehicle part constituting an object being painted, the 3D scanner 150 may be used to take 3D measurements by scanning the object being painted, and a 3D model may be generated on the basis of this measurement and this 3D model may be utilized for the painting.

[0066] Furthermore, the painting head 53 described is an inkjet painting head employing the piezoelectric substrate 62, but a painting head other than an inkjet painting head, such as a jet dispenser painting head, may equally be used.(4. Additional notes)

[0067] Details of the disclosure of the embodiment described above will be understood as follows, for example. [1] Specifically: A painting robot 10 for painting a predetermined area of a vehicle CP1, the painting robot comprising: a painting head unit 50 provided with a painting head 53 comprising a plural ity of nozzles 54 for ejecting paint droplets: a robot arm R1 which has the painting head unit 50 mounted on a tip end thereof and causes the painting head unit 50 to move to a desired position; a 3D scanner 150 for acquiring 3D painting data of a painting area PD1 which has been painted by the painting head 53; and a control unit (main control unit 100, robot arm control unit 70, head control unit 90) for controlling operation of the painting head 53 and the robot arm R1 on the basis of 3D image data sent from the 3D scanner 150, wherein the control unit (main control unit 100, robot arm control unit 70, head control unit 90) implements additional painting control when it is determined from the 3D painting data that there is a painting defect region PD2, which is a painting defect produced when the previous painting path PS1 was formed, and in the additional painting control, control is performed to eject paint droplets from the painting head 53 onto the painting defect region PD2 while the painting head 53 is moved so that the nozzle 54 which produced the painting defect region PD2 is moved to a different position.

[0068] By implementing the additional painting control, it is thus possible to compensate for the painting defect region PD2 and thereby improve painting quality. That is to say, if a painting defect such as a flaw or reduced thickness is produced in a painting area because of an ejection defect in a nozzle 54, the relevant painting position can be identified by the 3D scanner 150 and compensated by ejecting a sufficient quantity of droplets.

[0069] [2] Furthermore, in accordance with the embodiment above and in addition to the details disclosed in [1] above, in the additional painting control, the control unit (main control unit 100, robot arm control unit 70, head control unit 90) may perform control so that the nozzle 54 is moved to a different position by means of rotation of the painting head 53.

[0070] By rotating the painting head 53 to move the nozzle 54 to a different position in the additional painting control, it is thus possible to compensate for the painting defect region PD2 and thereby improve painting quality.

[0071] [3] Furthermore, in accordance with the embodiment above and in addition to [1] and [2] above or details disclosed in a combination thereof, when the previous painting path PS1 on which the initial painting is performed is an outward path, the control unit (main control unit 100, robot arm control unit 70, head control unit 90) may control operation of the painting head 53 and the robot arm R1 so that painting based on the additional painting control is implemented on a return path.

[0072] By implementing the additional painting control on the return path of the painting path PS1, it is thus simple to move the nozzle to a different position. It is therefore possible to compensate for the painting defect region PD2 and thereby improve painting quality.

[0073] [4] Furthermore, in accordance with the embodiment above and in addition to any of [1] to [3] above or details disclosed in a combination thereof, in the additional painting control, the control unit (main control unit 100, robot arm control unit 70, head control unit 90) may perform control so that the nozzle 54 is moved to a different position by moving the painting head 53 by a predetermined amount in a sub-scanning direction orthogonal to a main scanning direction on the painting path PS1, which is a movement direction.

[0074] By moving the painting head 53 by a predetermined amount in the sub-scanning direction orthogonal to the main scanning direction on the painting path PS1 which is the movement direction, it is thus simple to move the nozzle to a different position. It is therefore possible to compensate for the painting defect region and thereby improve painting quality.

[0075] [5] Furthermore, in accordance with the embodiment above and in addition to any of [1] to [4] above or details disclosed in a combination thereof, the 3D scanner 150 may acquire the 3D painting data within the same painting path PS1 as the painting path PS1 being painted.

[0076] 3D painting data is thus acquired within the same painting path PS1 as the painting path PS1 being painted, so there is no express need to move the 3D scanner 150 in order to acquire the 3D painting data. It is therefore possible to improve productivity of painting the vehicle CP1.

[0077] [6] Furthermore, in accordance with the embodiment above and in addition to any of [1] to [5] above or details disclosed in a combination thereof, the 3D scanner 150 may be fixed to the painting head 53.

[0078] The 3D scanner 150 is fixed to the painting head 53 and it is thus possible to identify a painting defect region PD2 using the 3D scanner 150 at the stage where painting has been performed. Consequently, there is no express need to move the 3D scanner 150 in order to acquire the 3D painting data. It is therefore possible to improve productivity of painting the vehicle CP1.

[0079] [7] Furthermore, in accordance with the embodiment above and in addition to any of [1] to [6] above or details disclosed in a combination thereof, the 3D scanner 150 may be provided separately from the painting robot 10.

[0080] The 3D scanner 150 is provided separately from the painting head 53, so the entirety of the painted painting film can be scanned with the 3D scanner 150 to identify painting defect regions PD2.[Key to Symbols]

[0081] 1··· Painting system, 10··· Painting robot, 20··· Robot main body, 21··· Stand, 22a··· First rotary shaft, 22b··· Second rotary shaft, 22c··· Third rotary shaft, 22d··· Fourth rotary shaft, 22e··· Fifth rotary shaft, 22f··· Sixth rotary shaft, 23··· Leg portion, 24··· First pivot arm, 25··· Second pivot arm, 26··· Rotating arm, 27··· Wrist portion, 40··· Paint supply unit, 41··· Supply line, 42··· Return flow path, 50··· Painting head unit, 52··· Nozzle-forming face, 53··· Painting head, 54··· Nozzle, 55··· Nozzle row, 55A··· First nozzle row, 55B··· Second nozzle row, 70··· Robot arm control unit, 71··· Memory, 80··· Paint supply control unit, 90··· Head control unit, 100··· Main control unit, 110··· Scanner control unit, 120··· Determination unit, 130··· Position sensor, 140··· Inclination sensor, 150··· 3D scanner, 200··· Image processor, 210··· Image processing unit, 220··· Memory, CP1··· Vehicle, PD1··· Painting area, PD2··· Painting defect region, PS1··· Painting path, R1··· Robot arm

Claims

1. Painting robot for painting a predetermined area of a vehicle, the painting robot comprising: a painting head unit provided with a painting head comprising a plurality of nozzles for ejecting paint droplets; a robot arm which has the painting head unit mounted on a tip end thereof and causes the painting head unit to move to a desired position; a 3D scanner for acquiring 3D painting data of a painting area which has been painted by the painting head; and a control unit for controlling operation of the painting head and the robot arm on the basis of 3D image data sent from the 3D scanner, characterized in that the control unit implements additional painting control when it is determined from the 3D painting data that there is a painting defect region, which is a painting defect produced when the previous painting path was formed, and in the additional painting control, control is performed to eject paint droplets from the painting head onto the painting defect region while the painting head is moved so that the nozzle which produced the painting defect region is moved to a different position.

2. Painting robot according to Claim 1, characterized in that in the additional painting control, the control unit performs control so that the abovementioned nozzle is moved to a different position by means of rotation of the painting head.

3. Painting robot according to any preceding Claim, characterized in that when the painting path on which the initial painting is performed is an outward path, the control unit controls operation of the painting head and the robot arm so that painting based on the additional painting control is implemented on a return path.

4. Painting robot according to any preceding Claim, characterized in that in the additional painting control, the control unit performs control so that the abovementioned nozzle is moved to a different position by moving the painting head by a predetermined amount in a sub-scanning direction orthogonal to a main scanning direction on the painting path, which is a movement direction.

5. Painting robot according to any preceding Claim, characterized in that the 3D scanner acquires the 3D painting data within the same painting path as the abovementioned painting path being painted.

6. Painting robot according to any preceding Claim, characterized in that the 3D scanner is fixed to the painting head.

7. Painting robot according to any of Claims 1 through 5, characterized in that the 3D scanner is provided separately from the painting head.

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