Operating method for painting equipment and correspondingly adapted painting equipment

Abstract

The present invention relates to an operating method for a coating system (e.g., a painting facility) for coating parts (e.g., automotive body parts). Prior to an actual coating run, the operating method provides a test run including the following steps: (S1) identifying a test pattern to be applied to a test surface; (S2) determining a control signal for controlling the coating system, the control signal being determined from the predetermined test pattern and intended to control the coating system so that an applicator applies the test pattern to the test surface; (S3) controlling the coating system with the control signal so that the coating system applies the test pattern to the test surface with the applicator; (S4) recording an image of the test pattern applied to the test surface with a sensor; (S5) determining a deviation between the predetermined test pattern and the recorded image of the actually applied test pattern; and (S7) determining a correction value for the control signal depending on the deviation between the predetermined test pattern and the recorded image of the actually applied test pattern. Furthermore, the present invention includes a correspondingly adapted coating system.

Description

[Technical Field]

[0001] The present invention relates to an operating method for a coating system (e.g., a painting facility) for coating parts (e.g., automotive body parts) with an applicator (e.g., a printhead) guided by a coating robot. Furthermore, the present invention relates to a correspondingly adapted coating system. In particular, the present invention relates to a coating method and a coating system using an application system that produces no or little overspray.

[0002] In modern paint facilities for painting automotive body parts, the automotive body parts to be painted are typically conveyed through the paint facility along a paint line and painted at multiple successive paint stations. At the end of the paint line, quality control is typically performed to monitor the quality of the applied paint. This quality control can be performed visually by a camera-based system using a combination of a camera and a stripe light projector, or by a human.

[0003] A drawback of this known type of quality inspection is that it is carried out only at the end of the paint line, so that in the event of a repeat defect, a large number of car body parts may be affected by the defect and require costly repairs.

[0004] The use of automated systems for quality control also represents a drawback, as it also requires additional capital investment.

[0005] For prior art, see also US Pat. No. 5,629,999, which, however, relates to a completely different principle of quality inspection: in this case, the quality inspection is carried out during the actual coating run, i.e. the test run and the coating run are carried out in parallel and coincident in time.

[0006] Finally, for the technical background of the invention, reference is also made to the technical standard DIN EN ISO9001:2015 “Quality management systems - Requirements”. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] DE 10048749 Summary of the Invention [Problem to be solved by the invention]

[0008] In view of the above, the invention is based on the problem of improving quality control in coating systems. [Means for solving the problem]

[0009] This object is achieved by an operating method for a coating system according to the invention and a correspondingly adapted coating system according to the invention.

[0010] In keeping with the prior art, the method of operation of the present invention includes a test run for quality assurance purposes in addition to an actual coating run for coating a part (e.g., an automobile body part). Therefore, it is preferred that one test run and another coating run are separated from each other, e.g., in time.

[0011] In the operating method according to the present invention, the test method comprises a number of steps which are carried out in succession, the individual steps of which will first be described only briefly below to allow a basic understanding of the invention.

[0012] In a first step, a test pattern to be applied to a test surface is first identified. For example, the test pattern may be provided as an image in the form of a file in a common image format. In general, the test pattern may be an image, a surface or partial surface of an object, or a surface filled with a pattern having a continuous boundary line. Furthermore, within the scope of the present invention, the test pattern may also be a barcode or a QR code.

[0013] The test surface can be, for example, a concealed area on the part to be coated (e.g., an automobile body part) or the surface of a separate piece (e.g., a paper tape from a paper roll), as described in more detail below.

[0014] In a further step, a control signal for controlling the coating system is then determined, the control signal being determined from the predetermined test pattern and intended to control the coating system during operation so that the applicator applies the test pattern to the test surface. The control signal, as will be described in more detail below, preferably includes various signals that serve to control the coating robot, the applicator, and / or other components of the coating system (e.g., conveyor system, paint supply). For example, the control signal may define a switching time for a coating agent valve, where the switching time determines at what point on the part surface the coating agent jet is switched on or off.

[0015] In a further step, the coating system is then controlled with a predetermined control signal so that the coating system applies the specified test pattern to the test surface. In a completely error-free operation, which is almost impossible, the applied test pattern would perfectly match the specified test pattern. In reality, however, there will be more or less deviation between the specified test pattern and the actually applied test pattern.

[0016] An image of the test pattern applied to the test surface is then recorded by a sensor, which may be, for example, a camera.

[0017] In a next step, the deviation between the predetermined test pattern on the one hand and the recorded image of the actually applied test pattern on the other hand is then determined. The deviation between the predetermined test pattern on the one hand and the recorded image of the actually applied test pattern on the other hand can be, for example, a splash, a gap between adjacent coating agent passes, a premature switch-on of the applicator, or a premature switch-off of the applicator, although various error cases are yet to be detailed.

[0018] Depending on the deviation thus determined between the predetermined test pattern on the one hand and the recorded image of the actually applied test pattern on the other hand, a correction value is then determined for the control signal, e.g., if the error is that the applicator is switched on too early, the correction value consists of a time delay of the switch-on point.

[0019] Based on detected deviations (e.g., splashes, voids = absence of coating) between the identified test pattern on the one hand and the recorded image of the actually applied test pattern on the other hand, the control system can initiate a cleaning or rinsing process of the applicator, after which application of the test pattern can be carried out again. Depending on the results of the evaluation of the test pattern, the control system can also terminate the coating process.

[0020] In addition to the test run described above, the operating method according to the present invention preferably also includes a coating run which temporally follows the test run, and also includes several steps which are briefly described below.

[0021] Thus, in a coating operation, a coating program for coating a part (e.g., an automobile body part) is first identified, and such coating programs are sufficiently known in the prior art that a separate description will not be provided. For example, such coating programs may be "taught" by a paint equipment operator, as is also well known in the prior art.

[0022] Control signals are then derived from the specified coating program and used to control the coating system. For example, the control signals may be used to control the applicator and coating robot. In practice, however, the control signals may also include signals for controlling other components of the coating system, such as the conveyor system and the paint supply system.

[0023] The control signals determined from the coating program are then corrected according to correction values ​​previously determined in a previous test run.

[0024] The coating system is then controlled using the corrected control signal during a coating run. For example, if an applicator is switched on with an undesired delay (i.e., too late) when a coating pass is being coated, the correction value ensures that the applicator is switched on at the corrected time during the actual coating run.

[0025] The term "applicator" as used in the context of the present invention should be understood in a general sense and is not limited to a particular type of applicator.

[0026] For example, the applicator may be an atomizer (e.g., rotary atomizer, air atomizer, air-mix atomizer, airless atomizer) that emits a spatially distributed spray of the coating agent, such atomizers being known from the prior art and therefore not described in detail here.

[0027] However, in a preferred embodiment of the present invention, the applicator is a nozzle applicator including multiple nozzles, each of which emits a jet of coating agent. For example, such a nozzle applicator may have more than 5, 10, or 20 nozzles. It should be noted here that the individual nozzles of the nozzle applicator of a preferred embodiment of the present invention can be controlled independently of each other, i.e., the coating agent jets from the individual nozzles can be switched on or off independently of each other. It should also be noted that the individual coating agent jets can be connected in the jet direction or can consist of multiple, separate coating agent droplets spaced apart from each other in the longitudinal direction of the jet. It should also be noted that the individual coating agent jets from the nozzles of the nozzle applicator are preferably aligned parallel to each other. Such nozzle applicators typically differ from sprayers in that the individual coating agent jets have a relatively small divergence angle, which can be less than 30°, less than 20°, less than 10°, less than 5°, or less than 2°. The advantage of such nozzle applicators compared to sprayers is their considerably greater application efficiency, so that they can be operated essentially without overspray, for example with application efficiencies of at least 90%, 95%, or 98%. Such nozzle applicators are used in modern painting plants for overspray-free painting, where they are also called printheads. The design and operation of such printheads themselves are described in German Patent Applications DE 102016014956 A1, DE 102016014946 A1, DE 102016014948 A1, DE 102016014953 A1, DE 102016014919 A1, DE 102016014947 A1, DE 102016014948 A1, DE 102016014947 A1, DE 102016014947 B1, DE 102016014947 C1, DE 102016014947 D1, DE 102016014947 E1, DE 102016014947 F2, DE 102016014947 F3, DE 102016014947 F4, DE 102016014947 F5, DE 102016014947 F6, DE 102016014956 A1, DE 102016014946 A1, DE 102016014948 A1, DE 102016014953 A1, DE 102016014919 B1, DE 102016014947 C2, DE 102016014947 F6, DE 1 , DE 102016014951 A1, DE 102016014952 A1, DE 102016014955 A1, DE 102016014944 A1, DE 102016014943 A1 and DE 102016014920 A1.The contents of these prior patent applications with respect to printhead design and operation are hereby incorporated in their entirety.

[0028] It should also be noted that the present invention is not limited to a specific type of coating agent. For example, the coating agent may be a paint, and the paint may be water-based or solvent-based. Furthermore, the coating agent (e.g., paint) may be a one-component coating agent or a two-component coating agent. In this context, it should also be noted that the coating agent may be, for example, an adhesive, a UV coating, a binder, a primer or paste-like material, a sealant, or an insulating material, to name a few.

[0029] As already mentioned above, correction values ​​for the control signals for controlling the coating system are determined during test runs, these correction values ​​preferably relating to the control of the applicators.

[0030] For example, the control signal may define a switching time for switching the applicator on or off individually, in particular for each nozzle of the nozzle applicator. The correction value may then define, for example, a positive or negative switching delay so that the nozzle is switched on or off as accurately as possible at the specified switching time in a real coating run. It should be noted that the correction value may be defined individually for each nozzle of the nozzle applicator. In the case of a nozzle applicator with 10 nozzles, for example, a correction value may be defined for each nozzle. The correction values ​​for the individual nozzles may be different and may, for example, compensate for component dispersion of the associated nozzle valve.

[0031] However, the correction values ​​determined during the test run may also influence the control of the coating robot. It should also be mentioned here that the correction values ​​preferably relate to both the control of the applicator and the control of the coating robot. However, the invention also claims variants of the invention in which the correction values ​​relate only to the control of the applicator or only to the control of the coating robot.

[0032] For example, the correction values ​​for individual path points of a coating path may define a change in the spatial position and / or spatial orientation of the applicator. For example, a typical coating program typically defines a coating path to be scanned by the paint impact point of the applicator used, where the coating path is specified by several path points as support points. The spatial position and / or spatial orientation of the applicator may then be specified at each path point. The correction values ​​may then define a change in the spatial position and / or spatial orientation of the applicator at each path point.

[0033] As already mentioned briefly above, the test surface may be located on the part to be coated, but application of the test pattern to the test surface would then result in an actual, undesirable coating on the part, although this is not a problem if the test surface is located in a hidden location on the part to be coated that is not visible during normal operation.

[0034] Alternatively, the test surface on the part to be coated can be overcoated during the actual coating run, and the test pattern can no longer be seen or interfered with.

[0035] Alternatively, the test surface on the part to be coated can be located in a location that will be covered in the finished state by an aftermarket part (e.g., a trim panel) or a built-in part (e.g., a dashboard, a seat), and the test pattern can be covered by the built-in or aftermarket part so that the applied test pattern does not detract from the quality appearance of the finished coated part.

[0036] Alternatively, the test surface can be located on a separate test substrate rather than on the part to be coated, so that the applied test pattern does not detract from the quality of the finished coated part. For example, the test substrate can be a test sheet that is coated with the test pattern during a test run and then disposed of. In one variation of the invention, the test substrate can be cleaned after application of the test pattern, for example, by wiping the test pattern off the test substrate.

[0037] Alternatively, the test substrate can be tape (e.g., paper tape) unwound from a tape roll. In this manner, multiple test patterns can be applied in succession, but the tapes should be unwound one at a time from the tape roll so that the next test pattern can then be applied to the tape.

[0038] As already mentioned briefly above, after the test pattern is applied to the test surface, a sensor records an image of the test pattern applied to the test surface. This sensor can be, for example, a camera that optionally records individual images or video, where the camera can operate at a frame rate of, for example, less than 60 frames per second, less than 30 frames per second, or less than 10 frames per second.

[0039] Furthermore, a stripe light projector can be used to project a stripe light pattern onto the test surface to illuminate the test pattern applied to the test surface, such stripe light projectors being known from the prior art and therefore not described separately.

[0040] The sensor can be a combination stripe light projector and camera.

[0041] In certain embodiments of the invention, sensors are also used for other purposes, such as detecting the position of an object in three-dimensional space. For this purpose, sensors can be attached to the robot, for example, to the hand axis. Thus, a test run according to the invention does not necessarily require additional sensors. Rather, sensors that are already present and used, for example, in a coating run, can also be used for the test run.

[0042] Analysis of images of the test pattern applied to the test surface acquired by a sensor (e.g., a camera) can also detect applicator malfunctions, and in the case of nozzle applicators, this can be done individually for each nozzle of the applicator. For example, the following applicator malfunctions can be detected as part of this analysis of the images of the test pattern: Nozzle applicator nozzle open for too long -Nozzle applicator nozzle opening too short -Premature opening of nozzle applicator nozzle Premature closure of nozzle applicator nozzle -Nozzle applicator nozzle opening too late -Nozzle applicator nozzle closing too late · Disturbing droplets on the test surface Uncoated holes on the test surface Uncoated gaps between adjacent paint passes Nozzle clogging (clogging)

[0043] In detecting nuisance droplets on the test surface, the droplet size of the nuisance droplets can also be determined by image evaluation within the scope of the present invention, and correction values ​​can be determined depending on the droplet size. Furthermore, rinsing and / or cleaning procedures can also be initiated when nuisance droplets are detected.

[0044] Furthermore, within the scope of the present invention, it is possible to determine which nozzle of the applicator emitted the nuisance droplet by evaluating the image of the test pattern. The open time of the nozzle from which the nuisance droplet was emitted can then be corrected depending on the droplet size of the nuisance droplet. For example, if a nozzle applicator has 10 nozzles and evaluation of the image of the test pattern indicates that the nuisance droplet was emitted from nozzle number 4, the open time of nozzle number 4 can be reduced accordingly to prevent the nuisance droplet from being emitted from nozzle number 4 during a subsequent actual coating run.

[0045] It should also be mentioned that the image acquired by the sensor (e.g., camera) may include the complete test pattern, where the offset between one identified test pattern and a recorded image of the other test pattern is preferably determined relative to the complete image.

[0046] However, it is alternatively possible for the sensor (e.g., a camera) to capture images of only parts of the test pattern, for example at the corners and edges of the test pattern, in which case the deviation between one identified test pattern and the captured image of the other test pattern is also determined only in these parts of the test pattern.

[0047] The above-mentioned sensors for taking images of the test pattern on the test surface also enable the sensors to determine the position and / or orientation of the part to be coated in a coating run, which can be used to adapt control signals for controlling the coating system in the actual coating run.

[0048] Although the operating method according to the invention, in particular the test run according to the invention on the one hand and the actual coating run on the other hand, has been described above, the invention also claims protection for a correspondingly adapted coating system for coating parts, which may be, for example, a painting plant for painting automotive body parts.

[0049] In keeping with the prior art, the coating system according to the invention firstly comprises an applicator for applying the coating agent, which may be, for example, a rotary sprayer or a print head, as already explained at the beginning.

[0050] Furthermore, in keeping with the prior art, the coating system according to the invention comprises a coating robot that moves the applicator over the part to be coated during operation. For example, this may be a multi-axis coating robot, e.g., having six or seven robot axes and serial robot kinematics. However, the term "coating robot" as used in the context of the present invention should be understood in a general sense and also includes manipulators such as linear axis systems with two or three axes (XY or XYZ) as well as combinations of linear axis systems and multi-axis robots.

[0051] Furthermore, in keeping with the prior art, the coating system of the present invention also includes a sensor (eg, a camera) for verifying the quality of the coating applied to the part.

[0052] Here, the operation of the coating system is controlled by a control unit, as known per se from the prior art, whose operation is specified by a control program.

[0053] The coating system according to the present invention is distinguished from the prior art in that the control program stored therein is designed to cause the coating system to carry out the operating method according to the present invention as described above.

[0054] It should also be mentioned that for coating systems, a sensor (e.g., a camera) can be connected to the applicator (e.g., a print head) and moved together with the applicator by a coating robot, where the orientation and position of the sensor relative to the applicator is fixed.

[0055] It should also be mentioned that the camera used as the sensor has a specific recording area, where the recording area of ​​the camera must include the color impact point of the applicator, which helps the camera to directly photograph the applied test pattern during application.

[0056] Further advantages of further embodiments of the invention are set out in the dependent claims and will be explained in more detail below together with the description of preferred embodiments of the invention and with reference to the drawings. [Brief explanation of the drawings]

[0057] [Figure 1] 4 is a flow chart showing a test run of the operating method according to the present invention. [Figure 2] 1 is a flow diagram showing an actual coating run following a test run. [Figure 3] 1 is a schematic diagram of a coating system according to the present invention. [Figure 4] Schematic diagram showing the possibilities of testing for defects and correcting them with test patterns. [Figure 5A] Schematic diagram showing application of target geometry to a part surface. [Figure 5B] Schematic diagram showing application of target geometry to a part surface. [Figure 5C] Schematic diagram showing application of target geometry to a part surface. [Figure 5D] Schematic diagram showing application of target geometry to a part surface. [Figure 6A] Schematic representation of defects that can occur during application of a target geometry to a part surface. [Figure 6B] Schematic representation of defects that can occur during application of a target geometry to a part surface. [Figure 6C] Schematic representation of defects that can occur during application of a target geometry to a part surface. [Figure 6D] Schematic representation of defects that can occur during application of a target geometry to a part surface. [Figure 6E] Schematic representation of defects that can occur during application of a target geometry to a part surface. [Figure 6F]Schematic representation of defects that can occur during application of a target geometry to a part surface. [Figure 6G] Schematic representation of defects that can occur during application of a target geometry to a part surface. [Figure 6H] Schematic representation of defects that can occur during application of a target geometry to a part surface. [Figure 7] Schematic of the sensor field of view with the applied test pattern and the resulting correction values. [Figure 8] 8 is an exemplary table containing correction values ​​for the values ​​determined in FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0058] In the following, a flow diagram is described in FIG. 1 showing a test run according to the invention, which is carried out before the actual coating run described in FIG.

[0059] In a first step S1, a test pattern is first identified. For example, the test pattern can be an image defined in the form of an image file in a common image format.

[0060] In a second step S2, a control signal used to apply the test pattern is calculated. The control signal is calculated from the test pattern and is used to control the coating system, in particular the applicator and the coating robot that guides the applicator. For example, the control signal can define the switching time of a coating agent valve, where the switching time determines at what point the coating agent jet is switched on or off.

[0061] In the next step S3, the coating system is then controlled with the control signal thus calculated, and in completely defect-free operation, the coating system applies the test pattern without any defects to a test surface, which can be, for example, an invisible portion of the surface of the part to be coated, or a separate test substrate, such as paper tape unwound from a paper roll, as will be described in more detail below.

[0062] In the next step S4, an image of the applied test pattern is then taken by an attached sensor.

[0063] In a next step S5, the recorded images of the test patterns are analyzed to detect deviations between the recorded images of the one test pattern and the other predetermined test pattern.

[0064] If these deviations are within a specified tolerance, the test pattern is acceptable. At step S6, the system branches to step S8 where control signals for a coating run are enabled, which will now be described in more detail.

[0065] On the other hand, if the test in step S6 indicates that the misalignment between one predetermined test pattern and the captured image of the other test pattern is outside of the acceptable range, the test pattern is not acceptable. In this case, step S6 leads to step S7, where a correction value for the control signal is calculated and the control signal is corrected accordingly.

[0066] The loop then returns to step S3. This loop is repeated until the check in step S6 indicates that the test pattern is acceptable or the maximum number of checks has been reached.

[0067] The corrected control signal is then finally released in step S8.

[0068] Below is described the flow diagram shown in FIG. 2, which illustrates the actual coating run following the test run shown in FIG.

[0069] In the first step S1, a coating program that controls the operation of the coating system is specified. For example, the coating program defines the course of a coating path traversed by the paint impact point of the applicator, where the coating path is defined by several path points (support points). Since the programming ("instruction") of such a coating program is known from the prior art, a detailed description thereof will be omitted.

[0070] In step S2, control signals for controlling the coating system are then derived from the control program.

[0071] In step S3, the control signal is then corrected by a correction value previously determined in a test run. For example, the control signal defines the switching time for switching on the individual nozzles of the nozzle applicator. The correction value may then define a positive or negative switching delay for each nozzle so that the individual nozzles are switched on or off as accurately as possible at the desired position. Furthermore, the correction value may directly affect the movement of the applicator and thus adjust the coating path accordingly.

[0072] In the next step S4, the coating system is then controlled with the corrected control signal to coat the part.

[0073] FIG. 3 shows a highly simplified schematic diagram of a coating system according to the present invention, which is largely of conventional design.

[0074] The coating system according to the present invention comprises a multi-axis coating robot 1 with serial robot kinematics and multi-axis robot hand axes which guide a camera 2 on the one hand and a print head 3 as an applicator on the other hand.

[0075] Furthermore, the coating system comprises a control unit 4 which controls the coating robot 1 according to a predetermined coating program. Furthermore, the control unit 4 is also connected to the print head 3 and controls the switching on and off of the individual nozzles of the print head 3. Furthermore, the control unit 4 is also connected to the camera 2 and thus captures the images acquired by the camera 2.

[0076] The figure further shows a paper roll 5 from which a paper tape 6 can be unwound, the paper tape 6 now forming a test substrate for applying a test pattern, as described above with reference to Figure 1. Thus, during a test run, the printhead 3 applies a test pattern to the paper tape 6 while the camera 2 takes an image of the applied test pattern. The control unit 4 then analyses the image and calculates correction values ​​for the control signals, as described in detail above.

[0077] In the following, the schematic diagram of Figure 4 shows the painting of a test pattern consisting of painting passes, where one painting pass includes at least one activation process of at least one nozzle of the applicator, and one painting pass includes at least one switch-off process of at least one nozzle of the applicator.

[0078] Figure 4 shows a test pattern in which applicator nozzles 1 through 5 are switched on in one paint pass. The vertical dashed lines indicate the switch-on and switch-off points of the individual nozzles of the print head with the uncorrected control signal. As the print head is moved in the painting direction indicated by the arrow, the individual nozzles must be opened at the left dashed line and then closed at the next right dashed line. Deviations from the target switch-on times can occur in this paint pass, for example due to component tolerances.

[0079] Applicator nozzle number 1 is switched on too late for this paint pass in this example, but is switched off at the correct time.

[0080] Applicator nozzle number 2 is turned on at the correct time for this paint pass, but is turned off too early.

[0081] Applicator nozzle number 3 is switched on too late and switched off too early for this paint pass.

[0082] Applicator nozzle number 4 is switched on too early and switched off too late for this paint pass.

[0083] Only nozzle number 5 is turned on at the correct time and turned off at the correct time for this paint pass.

[0084] In the test run according to the invention, the correction signal -Δt for the switch-on time of the nozzle is then e , +Δt e and correction value -Δt for the nozzle switch-off time a , +Δt a are calculated for the first four nozzles, but first the correction distance s k and then the corresponding time correction value -Δt e , +Δt e , -Δt a , +Δt a Using known parameters (e.g., the scanning speed v of the applicator), the switching time difference -Δt e , +Δt e , -Δt a , +Δt a The corrected distance s is determined k The switch-on and switch-off points are calculated from the correction signal -Δt e , +Δt e , -Δt a , +Δt a so that the nozzle opens or closes at the correct time in the actual coating run.

[0085] Here, the following applies: s = distance between the start and end of painting for each nozzle sz = desired distance s1, s2, s3, s4 = length of solid line s k = Correction distance to be corrected +Δt e = correction due to delayed switch-on time -Δt e = compensation due to early switch-on times +Δt a = correction due to delayed switch-off time -Δta = compensation due to early switch-off times v Painting speed Example of v=800mm / sec and s=0.2mm ⇒ Δt=0.25ms

[0086] 5A-5D show the application of a target geometry 7 on a part 8 to be coated.

[0087] To achieve the coating of the target geometry 7, coating passes 9 are applied by N nozzles (three in this example), each of which is adjacent to one another and forms a continuous coating agent film in the finished state.

[0088] Further, transverse passes 10, 11 are applied to the ends of application pass 9 to complete application of target geometry 7.

[0089] 6A-6H show various possible defects that can be detected and corrected in a test run according to the present invention by calculating corresponding correction values ​​for the control signal.

[0090] In the case of the error shown in FIG. 6A, application pass 9 starts too early and ends too late, ie the individual nozzles are switched on too early and switched off too late.

[0091] In the case of the error shown in FIG. 6B, disturbing droplets 12 occur at the edges of the application.

[0092] In the case of the error shown in FIG. 6C, the application is offset from the target geometry 7.

[0093] In the case of the error shown in FIG. 6D, only the traversal paths 10, 11 are offset relative to the target geometry 7.

[0094] In the case of the error shown in FIG. 6E, the traversal paths 10, 11 are either too short or too long.

[0095] In the case of the error shown in FIG. 6F, a gap 13 occurs between adjacent application passes 9.

[0096] In the error shown in FIG. 6G, traverse path 10 is too thin, while traverse path 11 is too thick.

[0097] In the case of the error shown in FIG. 6H, a gap 14 occurs in the application path 9.

[0098] Within the scope of the test run according to the invention, correction values ​​for the defect examples shown in Figures 6A-6H can be calculated so that the defects no longer occur in the application.

[0099] Figure 7 shows a modification of Figure 4 for an applicator with 13 nozzles. To avoid repetition, please refer to the description of Figure 4.

[0100] In addition to FIG. 4, FIG. 7 shows the camera field of view 15 captured by the camera during the test drive.

[0101] The table in FIG. 8 shows the relevant time correction values ​​±Δt for the control of the individual nozzles of the applicator for the test run described in FIG. e , ±Δt a Shows.

[0102] The present invention is not limited to the preferred embodiments described above. Rather, the present invention claims the subject matter and features of the dependent claims independently of the claims to which they refer, particularly without the features of the main claim. Thus, the present invention encompasses different aspects of the invention that enjoy protection independent of one another. For example, the present invention claims protection for a coating run independently of a test run.

[0103] [Note] [Appendix 1] 1. A method of operating a coating system for coating parts by means of an applicator (3) guided by a coating robot (1), in particular for painting automotive body parts in a painting installation, comprising: a) Test runs for quality assurance purposes; Equipped with The test run b) identifying a test pattern (7) to be applied to a test surface (6, 8) (S1); c) determining a control signal for controlling the coating system, The control signal is c1) determined from said predetermined test pattern (7), and c2) for the purpose of controlling the coating system during operation so that the applicator (3) applies the test pattern (7) to the test surface (6, 8), Process (S2), d) controlling (S3) the coating system with the control signal so that the coating system applies the test pattern (7) to the test surface (6, 8) with the applicator (3); e) recording (S4) by a sensor (2) an image of the test pattern (7) applied to the test surface (6, 8); f) the deviation (s) between the predetermined test pattern (7) and the recorded image of the test pattern (7) actually applied k ) (S5), and g) the deviation (s) between the predetermined test pattern (7) and the recorded image of the test pattern (7) actually applied k ) to calculate a correction value (-Δt e , +Δt e , -Δt a , +Δt a ) determining step (S6); A method of operation comprising:

[0104] [Appendix 2] The coating operation after the test operation is a) presetting a coating program for coating the part; b) determining control signals for controlling said coating system in accordance with said predetermined coating program; c) the correction value (-Δt e , +Δt e , -Δt a , +Δt a correcting the control signal for the coating operation according to d) controlling the coating system with the corrected control signal; 2. The method of claim 1, comprising:

[0105] [Appendix 3] a) the applicator (3) for applying the test pattern (7) has a plurality of nozzles, in particular more than 5, more than 10 or more than 20 nozzles, and / or b) the applicator (3) emits a coating agent jet from each of the individual nozzles; and / or c) the individual nozzles of the applicator (3) are controllable independently of each other, and / or d) each of the coating agent jets is composed of droplets of coating agent that are connected to each other in the direction of jetting or that are separated from each other; and / or e) the individual coating agent jets are aligned parallel to one another; and / or f) each of the individual coating agent jets has a jet divergence angle of less than 30°, less than 20°, less than 10°, less than 5°, or less than 2°; and / or g) the applicator (3) operates essentially without overspray, in particular with an application efficiency of at least 90%, 95% or 98%; and / or h) the applicator (3) is a print head; The operating method described in Appendix 1 or 2.

[0106] [Appendix 4] The correction value (-Δt e , +Δt e , -Δt a , +Δt a 4. The method of claim 1, wherein the control of the applicator (3) is related to the control of the applicator (3).

[0107] [Appendix 5] a) the control signals define switching times for switching the applicator (3) on or off, in particular for each nozzle of the applicator (3) individually; and b) the correction value (-Δt e , +Δt e , -Δt a , +Δt a ) is a positive or negative switching delay (-Δt e , +Δt e , -Δt a , +Δt a ), Operation method described in Appendix 4.

[0108] [Appendix 6] a) the control signal defines, in particular for each nozzle of the applicator (3) individually, a switch-on period during which the applicator (3) is switched on, and b) the correction value defines, in particular for each nozzle of the applicator (3) individually, a positive or negative change in the switch-on period of the applicator (3), The operating method described in Appendix 4 or 5.

[0109] [Appendix 7] 7. The operating method according to any one of claims 1 to 6, wherein the correction value relates to the control of the coating robot (1).

[0110] [Appendix 8] the correction value for the path point of the painting path defines a change in the spatial position and / or spatial orientation of the applicator (3), Operation method described in Appendix 7.

[0111] [Appendix 9] a) rinsing the applicator (3) with a rinse agent; b) cleaning the applicator (3) on its exterior, c) stopping the coating operation; At least one of the operations is performed to determine the deviation (s k ), in particular, depending on the deviation (s k ) exceeds a given limit, 10. The method of any one of claims 1 to 8.

[0112] [Appendix 10] a) the test surfaces (6, 8) are positioned on the part to be coated, b) the test surfaces (6, 8) on the part to be coated are optionally located in a position that is hidden in the finished state by an aftermarket part, in particular a panel, or by an in-built part, in particular a dashboard or a seat, so that the applied test pattern (7) does not impair the perceived quality of the finished coated part; 10. The method of any one of claims 1 to 9.

[0113] [Appendix 11] a) the test surfaces (6, 8) are located on a separate test substrate and not on the part to be coated, so that the applied test pattern (7) does not impair the appearance of the finished coated part; b) the separate test substrate can optionally be cleaned to remove the test pattern (7), in particular by wiping the test pattern (7) from the test substrate; c) the separate test substrate is optionally a tape unwound from a tape roll, in particular a paper tape; 11. The method of any one of claims 1 to 10.

[0114] [Appendix 12] a) said sensor (2) comprises a camera (2) for determining said test pattern (7) applied to said test surface (6, 8), in particular in combination with a stripe light projector; b) said camera (2) optionally records individual images; c) the camera (2) optionally records video, in particular at a frame rate of less than 60 frames / s, less than 30 frames / s or less than 10 frames / s; 12. The method of any one of claims 1 to 11.

[0115] [Appendix 13] a) an image of the test pattern (7) applied to the test surface (6, 8) is analyzed to detect possible malfunctions of the applicator (3), in particular for each nozzle of the applicator (3) individually; and / or b) during the analysis of the image of the test pattern (7), b1) the nozzle of the applicator (3) being open for too long; b2) too short opening of the nozzle of the applicator (3); b3) premature opening of the nozzle of the applicator (3); b4) premature closure of the nozzle of the applicator (3); b5) too late opening of the nozzle of the applicator (3); b6) too late closing of the nozzle of the applicator (3); b7) a disturbing droplet (12) on said test surface (6, 8); b8) uncoated holes (14) on said test surfaces (6, 8); b9) Uncoated gaps between adjacent paint passes; At least one malfunction of the applicator (3) is detected, such as 13. The method of any one of claims 1 to 12.

[0116] [Appendix 14] a) nuisance droplets (12) on the test surface (6, 8) are detected in an image of the test pattern (7) applied to the test surface (6, 8), b) determining the droplet size of the nuisance droplet (12); and c) the correction value (-Δt e , +Δt e , -Δt a , +Δt a) is determined, 14. The method of any one of claims 1 to 13.

[0117] [Appendix 15] a) determining from which nozzle of the applicator (3) the nuisance droplet (12) was emitted by analyzing the image of the test pattern (7); and b) the opening time of the nozzle from which the interfering droplet (12) was ejected is corrected according to the droplet size of the interfering droplet; 15. The method of operation described in Appendix 13 or 14.

[0118] [Appendix 16] a) the image acquired by the sensor (2) includes the complete test pattern (7), and the deviation (s k ) is determined, or b) the image acquired by the sensor (2) includes only a portion of the test pattern (7), in particular only certain corners and edges, and only in this portion the deviation (s k ) is determined, 16. The method of any one of claims 1 to 15.

[0119] [Appendix 17] 1. A coating system for coating parts, in particular for painting automotive body parts, comprising: a) an applicator (3) for applying the coating agent; b) a coating robot (1) for moving said applicator (3) over said part to be coated; c) a sensor (2) for verifying the quality of the coating applied to said part; and d) a control unit for controlling said applicator (3) and said coating robot (1) according to a predetermined control program; and e) the control program is designed to cause the coating system to perform the operating method of any one of claims 1 to 16; Coating system.

[0120] [Appendix 18] a) the sensor (2) is connected to the applicator (3) and is moved together with the applicator (3) by a coating robot (1), and / or b) the sensor (2) is a camera (2) having a recording area that includes the paint impact point of the applicator (3), and / or c) the sensor (2) for the test run is the sensor (2) also used in the coating run, and no additional sensor (2) is required for the test run; 18. The coating system of claim 17. [Explanation of symbols]

[0121] 1. Coating robot 2 Cameras 3 print head 4. Control Unit 5 paper rolls 6 paper tape 7 Target Geometry (Test Pattern) 8 parts 9 coating passes 10, 11 Crossing Pass 12 Droplets 13 Gap 14 Missing 15 Camera Field of View

Claims

1. A method of operating a painting system for painting automotive body parts, comprising: a) Test runs for quality assurance purposes; Equipped with The test run a1) a step (S1) of identifying a test pattern (7) to be applied to a test surface (6, 8); a2) determining a control signal for controlling the painting equipment, The control signal is determined from said predetermined test pattern (7), and The purpose of the invention is to control the coating installation during operation so that the applicator (3) applies the test pattern (7) to the test surface (6, 8). Step (S2), a3) controlling the coating equipment with the control signal so that the coating equipment applies the test pattern (7) to the test surface (6, 8) with the applicator (3); a4) recording (S4) an image of the test pattern (7) applied to the test surface (6, 8) by a sensor (2); a5) Deviation (s) between the predetermined test pattern (7) and the recorded image of the test pattern (7) actually applied ｋ ) (S5), and a6) the deviation (s) between the predetermined test pattern (7) and the recorded image of the test pattern (7) actually applied ｋ ) to calculate a correction value (-Δt ｅ , +Δt ｅ , -Δt ａ , +Δt ａ ) determining step (S6); Including, b) a coating run after the test run, b1) presetting a coating program for coating the automotive body part; b2) determining control signals for controlling the painting equipment in accordance with the predetermined coating program; b3) correcting the control signal for the coating run according to the correction values ​​(-Δt e , +Δt e , -Δt a , +Δt a ) determined in a previous test run; and b4) controlling the painting equipment with the corrected control signal; A method of operation comprising:

2. a) the applicator (3) for applying the test pattern (7) has a plurality of nozzles, and / or b) the applicator (3) emits a coating agent jet from each of the individual nozzles; and / or c) the individual nozzles of the applicator (3) are controllable independently of each other, and / or d) each of the coating agent jets is composed of droplets of coating agent that are connected to each other in the direction of jetting or that are separated from each other; and / or e) the individual coating agent jets are aligned parallel to one another; and / or f) each of the individual coating agent jets has a jet divergence angle of less than 30°, less than 20°, less than 10°, less than 5°, or less than 2°; and / or g) the applicator (3) operates essentially without overspray, and / or h) said applicator (3) is a print head; The operating method according to claim 1 .

3. The correction value (-Δt ｅ , +Δt ｅ , -Δt ａ , +Δt ａ 3. The method according to claim 1, wherein the control of the applicator (3) is related to the application of the liquid.

4. a) the control signal defines the switching times for switching the applicator (3) on or off, and b) the correction value (-Δt ｅ , +Δt ｅ , -Δt ａ , +Δt ａ ) is the positive or negative switching delay (-Δt ｅ , +Δt ｅ , -Δt ａ , +Δt ａ ) to define The operating method according to claim 3.

5. a) the control signal defines a switch-on period during which the applicator (3) is switched on, and b) the correction value defines a positive or negative change in the switch-on period of the applicator (3), 5. The operating method according to claim 3 or 4.

6. 6. The method according to claim 1, wherein the correction value is related to the control of a coating robot (1).

7. a) rinsing the applicator (3) with a rinse agent; b) cleaning the applicator (3) on its outside, c) stopping the coating operation; At least one of the operations is performed to determine the deviation (s ｋ ) is executed according to The operating method according to any one of claims 1 to 6.

8. a) the test surface (6, 8) is positioned on the automotive body part to be coated; b) the test surfaces (6, 8) on the automotive body part to be coated are located in a position that will be hidden by an aftermarket part in the finished state; The operating method according to any one of claims 1 to 7.

9. a) the test surfaces (6, 8) are located on a separate test substrate and not on the automotive body part to be coated, so that the applied test pattern (7) does not detract from the appearance of the finished coated automotive body part; b) the separate test substrate is capable of cleaning the test pattern (7); c) the separate test substrate is a tape; 9. The operating method according to any one of claims 1 to 8.

10. a) the sensor (2) comprises a camera (2) for determining the test pattern (7) applied to the test surface (6, 8), b) the camera (2) records individual images; 10. The operating method according to any one of claims 1 to 9.

11. a) an image of the test pattern (7) applied to the test surface (6, 8) is analyzed to detect possible malfunctions of the applicator (3), and / or b) during the analysis of the image of the test pattern (7), b1) the nozzle of the applicator (3) being open too long; b2) too short opening of the nozzle of the applicator (3); b3) premature opening of the nozzle of the applicator (3); b4) premature closure of the nozzle of the applicator (3); b5) too late opening of the nozzle of the applicator (3); b6) too late closing of the nozzle of the applicator (3); b7) uncoated holes (14) on the test surfaces (6, 8); b8) Uncoated gaps between adjacent paint passes; At least one malfunction of the applicator (3) is detected, such as The operating method according to any one of claims 1 to 10.

12. a) the image acquired by the sensor (2) includes the complete test pattern (7), and the deviation (s ｋ ) is determined, or b) the image acquired by the sensor (2) includes only a portion of the test pattern (7), and the deviation (s) is detected only in this portion. ｋ ) is determined, 12. The operating method according to any one of claims 1 to 11.

13. A painting system for painting automobile body parts, comprising: a) an applicator (3) for applying the coating agent; b) a coating robot (1) for moving said applicator (3) over said automotive body part to be coated; c) a sensor (2) for verifying the quality of the coating applied to the automotive body part; and d) a control unit for controlling said applicator (3) and said coating robot (1) according to a predetermined control program; and e) the control program is designed so that the painting installation carries out the operating method according to any one of claims 1 to 12; Painting equipment.

14. a) the sensor (2) is connected to the applicator (3) and is moved together with the applicator (3) by a coating robot (1), and / or b) the sensor (2) is a camera (2) having a recording area that includes the paint impact point of the applicator (3), and / or c) the sensor (2) for the test run is the sensor (2) also used for the coating run, and no additional sensor (2) is required for the test run; The painting facility according to claim 13.

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