Including the spraying device for vibration sensors and the corresponding operating methods

Abstract

This invention relates to a spraying apparatus (1) having multiple fault-prone components (9-12, 15-18, 19-22), a vibration sensor (22) for detecting mechanical vibrations in the spraying apparatus (1) and converting them into vibration signals that can be used for control technology evaluation, and an evaluation unit (23) for evaluating the vibration signals from the vibration sensor (22) and diagnosing operational malfunctions of one of the fault-prone components (9-12, 15-18, 19-22) in the spraying apparatus (1) based on the vibration signals. According to the invention, the evaluation unit (23) diagnoses various operational malfunctions of the various fault-prone components (9-12, 15-18, 19-22) of the spraying apparatus (1) by evaluating the vibration signals from the vibration sensor (22). Furthermore, the invention also includes related operating methods.

Description

Technical Field

[0001] This invention relates to a spraying apparatus (e.g., a spraying robot) for spraying components (e.g., vehicle body components) with a spraying agent (e.g., paint). Furthermore, the invention also relates to a corresponding method of operation. Background Technology

[0002] In modern automotive body painting equipment, a rotary atomizer is typically used as the application device. The bell cup rotates at high speed, causing the paint to be applied to be opened and atomized by the rotating bell cup.

[0003] However, during operation, the rotary atomizer may become unbalanced, leading to malfunctions. This imbalance can occur, for example, if the bell cup collides with the room boundary (e.g., the wall of the painting booth). Such operational disturbances to the rotary atomizer should be detected during operation so that the malfunction can be corrected without significantly impacting the painting process.

[0004] A coating device capable of detecting this type of operational malfunction in a rotary atomizer is known from WO2016 / 180521A1. For this purpose, a vibration sensor is used to analyze the mechanical vibrations emitted from the rotary atomizer, thereby detecting the operational malfunction.

[0005] However, a drawback of this known concept is that evaluating vibration signals from various vibration sensors can only lead to conclusions about specific operational faults in the rotary atomizer. Furthermore, this known concept makes it impossible to detect and locate operational faults in other potentially faulty components of the coating equipment. Moreover, it makes it impossible to distinguish between different types of operational faults.

[0006] Finally, the technical background of the present invention is also described in US2019 / 0314842A1.

[0007] Therefore, the objective of this invention is to provide an improved spraying apparatus and a corresponding operating method. Summary of the Invention

[0008] This task is accomplished by the spraying apparatus according to the invention or by the corresponding operating method according to the independent claims.

[0009] The spraying apparatus according to the invention is preferably used for spraying paint onto vehicle body parts. However, the invention is not limited to this specific application area in terms of the type of part to be sprayed and the type of spraying agent. For example, the spraying apparatus according to the invention can also apply other spraying agents, such as insulating materials, sealants, or adhesives, to name just a few. Within the scope of the invention, there is no limitation on the type of part to be sprayed. The spraying apparatus according to the invention can also be designed for spraying other parts besides vehicle body parts. Exemplary parts are aircraft parts or wind turbine parts.

[0010] However, in a preferred embodiment of the invention, the spraying device is a spraying robot, which is known in the prior art, and therefore, the structural details of the spraying robot will not be described in detail here.

[0011] The spraying apparatus according to the present invention, based on the aforementioned known spraying apparatus, has several components prone to failure, which may malfunction during operation. It has only been mentioned above that operational failures may occur in the rotary atomizer, and these failures are caused by imbalance. However, the concept of prone-to-failure components should be generally understood within the scope of the present invention, and is not limited to the rotary atomizer. Conversely, operational failures can also occur in other components within the scope of the present invention, as will be explained in detail later.

[0012] Furthermore, the spraying apparatus according to the invention, based on the known spraying apparatus described at the beginning, also has at least one vibration sensor to detect mechanical vibrations in the spraying apparatus and generate a vibration signal that can be evaluated in terms of control technology and reproduce the mechanical vibrations.

[0013] Furthermore, the spraying apparatus according to the present invention, based on the known spraying apparatus described at the beginning, also has an evaluation unit, the function of which is to evaluate the vibration signal emitted from the vibration sensor and diagnose the operational failure of one of the components in the spraying apparatus that is prone to failure based on the vibration signal.

[0014] The spraying apparatus according to the present invention is characterized in that the evaluation unit can not only detect operational faults, but also diagnose various operational faults of different components that are prone to failure by evaluating vibration signals.

[0015] On the one hand, the evaluation unit can therefore distinguish different types of operational faults by evaluating vibration signals, which is impossible in the prior art.

[0016] On the other hand, the evaluation unit can also distinguish operational faults in different components that are prone to failure. For example, by evaluating vibration signals, the evaluation unit can distinguish whether there is an imbalance in the bell cup or damage to the bearings of the painting robot.

[0017] As briefly mentioned above, within the scope of this invention, operational malfunctions of various components in the spraying device that are prone to failure can be monitored, that is, not only operational malfunctions of the rotary atomizer, which are known in the prior art.

[0018] For example, components prone to failure and whose operational malfunctions are detected may be painting robots (e.g., coating robots), which themselves have multiple robot axes. Typically, such painting robots have serial robot kinematics and at least six robot axes, which is known in the prior art. In a preferred embodiment of the invention, the painting robot has a robot base, a pivotable robot component, a proximal manipulator, a distal manipulator, and / or a robot hand axis. Various operational malfunctions can occur in such painting robots, such as bearing failure, gearbox failure, or motor failure.

[0019] Furthermore, components prone to malfunction and whose operational failures can be detected may be the application device for applying the spray agent. As an example of such an application device, a rotary atomizer has already been mentioned above. However, within the scope of this invention, other types of application devices can also be found to be prone to operational failures, such as the so-called printhead, which essentially applies the spray agent without overspray.

[0020] Another component prone to failure and whose malfunctions can be detected during operation is the compressed air turbine, which, for example, is used in rotary atomizers to rotate the turbine shaft, as is known in the prior art. In such compressed air turbines, for example, bearing failure can occur as an operational malfunction.

[0021] As briefly mentioned above, in the case of a rotating atomizer, the collision between the bell cup and the chamber boundary (such as the wall of the painting booth) can cause imbalance. Therefore, the bell cup is also a component prone to failure and whose malfunctions are detected during operation.

[0022] Furthermore, within the scope of this invention, it is possible to detect an operational malfunction of the metering pump that measures the spraying agent to the application device.

[0023] Furthermore, as briefly mentioned above, conventional painting robots have motors, gearboxes, and bearings, which can also exhibit operational malfunctions that can be diagnosed within the scope of this invention. Therefore, components prone to malfunction and whose operational failures can be monitored within the scope of this invention can also be the motors, gearboxes, and / or bearings of the painting robot.

[0024] Finally, spraying equipment typically includes controllable pressure valves, such as spray valves for controlling the flow of spraying agent or rinsing agent for controlling the flow of rinsing agent. These pressure valves can also malfunction during operation. Therefore, components prone to malfunction and whose malfunctions are detected during operation can also be controllable pressure valves, such as valves in rotary atomizers. Generally, the monitored components of a spraying equipment can also be any valve, such as electrically controlled valves.

[0025] The preceding description of the various components prone to failure is not exhaustive. Conversely, the concepts according to the present invention can also be used to detect operational malfunctions in other components of the spraying apparatus.

[0026] As mentioned above, the concept according to the invention is preferably applicable to detecting malfunctions in painting robots (e.g., coating robots) that use guided applicators (e.g., rotary atomizers). Here, operational malfunctions of the applicator can be detected by evaluating the vibration signal from a vibration sensor. The vibration sensor can be mounted on the painting robot and spaced apart from the applicator. Mechanical vibrations emitted by the applicator are transmitted to the vibration sensor through the painting robot, thus giving the painting robot certain vibration transmission characteristics. The evaluation unit can then evaluate the vibration signal from the vibration sensor, taking into account the vibration transmission characteristics of the painting robot. For example, the vibration sensor can be mounted on the robot base, a pivotable robot component, a proximal robotic arm (“Arm 1”), a distal robotic arm (“Arm 2”), or a robot hand shaft, to name just a few examples.

[0027] Spatial separation between the application device to be monitored and the vibration sensor is technically advantageous, especially if the spraying robot has an electrostatic spraying agent dispensing system. In this case, the application device is located in a high-voltage area, so placing the vibration sensor directly on or within the application device would be problematic because the vibration sensor would also be at a high voltage potential. Conversely, spatial separation between the application device to be monitored and the vibration sensor offers the possibility of placing the vibration sensor in an electrically connected area, making interrogation of the vibration sensor much easier since potential isolation is not required.

[0028] As briefly mentioned above, the concept according to the present invention provides the possibility of diagnosing and differentiating various operational malfunctions of the spraying device.

[0029] One possible operational malfunction is an imbalance in the bell cup of a rotary atomizer, as briefly mentioned above. However, this imbalance can occur not only in the bell cup but also in other rotating parts that rotate with the bell cup, such as the turbine shaft of the rotary atomizer.

[0030] Therefore, another possible malfunction is an imbalance in the components that rotate with the bell cup in the rotary atomizer.

[0031] Another possible failure is mechanical wear of bearings (such as rolling bearings), such as those in a rotary atomizer or a spraying robot. This bearing can be any type of bearing, such as those in a gearbox, shaft, or motor; a few examples are given here.

[0032] Other possible operational malfunctions that can be detected during operation include gearbox oil leaks, insufficient gearbox oil, or oil leaks or insufficient oil in the spraying robot's motor. These malfunctions can lead to increased friction, resulting in measurable vibrations.

[0033] Furthermore, assembly faults, such as incorrect tightening torque of fastening screws or incorrect assembly of drive shafts, can also be detected within the scope of this invention.

[0034] In addition, operational malfunctions may also include the fact that the metering pump's drive shaft is not installed correctly or is structurally unsuitable.

[0035] Finally, within the scope of this invention, it is also possible to detect collisions between the painting robot and obstacles, such as room boundaries (e.g., partition walls of the painting room) or with another painting robot.

[0036] The above description of various possible operational faults is not exhaustive. Instead, based on the concepts of this invention, other operational faults reflected in changes in vibration behavior can also be detected.

[0037] Various possibilities exist regarding the design and operation modes of the vibration sensor within the scope of this invention. For example, the vibration sensor may be a two-axis or three-axis accelerometer. Alternatively, it is also possible that the accelerometer is a two-axis or three-axis accelerometer that also includes a two-axis or three-axis gyroscope. Therefore, in terms of the design and operation of the vibration sensor, this invention is not limited to certain types of vibration sensors.

[0038] As briefly mentioned above, spraying equipment typically has an electrostatic spraying agent feeding system, thus possessing a high-voltage zone and an electrically connected zone. The vibration sensor is then preferably located in the electrically connected zone, which simplifies vibration sensor interrogation as no potential isolation is required.

[0039] Furthermore, it should be mentioned that painting facilities typically also have explosion-proof rooms, which may, for example, be equipped with air purging systems. Such explosion-proof rooms are described, for example, in technical standards IEC / EN 60079-11-Part11, IEC / EN 60079-25-Part25, and IEC / EN 60079-14-Part14. Vibration sensors can be located inside or outside the explosion-proof room.

[0040] Regarding the spatial arrangement of vibration sensors in a painting robot, it should also be mentioned that such painting robots all have housings for shaft drivers of each robot axis. For example, vibration sensors can be arranged in the housings of shaft drivers for the fourth, fifth, or sixth robot axes.

[0041] As mentioned above, the evaluation unit assesses the vibration signals provided by the vibration sensors in order to detect operational malfunctions in the spraying equipment. Alternatively, it may first calculate the vibration characteristic values ​​from the vibration signals, and then the evaluation unit performs analysis based on these values. For example, the vibration characteristic values ​​could be the effective value of the vibration signal, the maximum value of the vibration signal, the first-order amplitude of the vibration signal, the higher-order amplitude of the vibration signal, the distortion coefficient of the vibration signal, or the crest coefficient of the vibration signal, to name just a few examples.

[0042] In one variant of the invention, the vibration characteristic value is calculated directly in the vibration sensor by sensor electronics integrated in the vibration sensor.

[0043] On the other hand, in another variation of the invention, the vibration characteristic value is first calculated from the vibration signal in an evaluation unit, which is preferably structurally separate from the vibration sensor. However, in another case, the evaluation unit is structurally integrated into the vibration sensor, or forms a structural unit with the vibration sensor by placing the evaluation unit directly on the vibration sensor.

[0044] If the vibration sensor and the evaluation unit are spatially separate, then the evaluation unit may also consist of multiple spatially separate parts, such as the evaluation unit and robot control unit on a painting robot.

[0045] Generally, some evaluation work can be performed directly on the vibration sensor, while other evaluation work is performed in spatially separated evaluation units. For example, individual signals can be filtered and superimposed directly at the vibration sensor to form a whole signal, while the vibration characteristic value is calculated from the whole signal in the spatially separated evaluation unit.

[0046] In principle, the comparison of vibration characteristic values ​​with one or more limit values ​​can be performed directly in the sensor or in a spatially separated evaluation unit, or partly directly in the sensor and partly in a spatially separated evaluation unit.

[0047] Furthermore, within the scope of this invention, vibration characteristic values ​​can also be calculated using software connected to the evaluation unit or running in the microprocessor integrated into the evaluation unit.

[0048] In evaluating vibration characteristic values, for example, these values ​​can be compared to limit values ​​(e.g., maximum values). If the vibration characteristic value exceeds the limit value, a first warning signal is generated. This first warning signal can then be displayed to the operator of the spraying equipment, for example, visually and / or acoustically. However, alternatively, the first warning signal may simply be an error indicator in the machine control system.

[0049] Furthermore, within the scope of this invention, the evaluation unit can monitor vibration characteristic values ​​during the operation of the spraying apparatus. The evaluation unit can then compare these vibration characteristic values ​​with the predetermined aging behavior of a specific component. If the comparison indicates that the vibration characteristic value requires maintenance or replacement of a faulty component due to wear, a second warning signal is generated. Therefore, the second warning signal can be a maintenance signal, instructing the operator that maintenance should be performed. However, the second warning signal can also be a stop signal, instructing the operator that operation must be interrupted, and this stop signal can also automatically cause the operation to stop.

[0050] Furthermore, it should be mentioned that the spectrum can also be used as part of the evaluation of the vibration signal (e.g., evaluating the first-order and / or higher-order amplitudes). Multiple different total signals can also be used to calculate one or more vibration characteristic values; for example, multiple vibration characteristic values ​​can be calculated from different total signals, or multiple different total signals can be used to calculate a single vibration characteristic value.

[0051] Furthermore, it is possible to calculate multiple vibration parameters from multiple individual signals, such as from all individual signals or only from selected individual signals.

[0052] As mentioned above, the evaluation unit monitors the vibration behavior of components prone to failure. For example, this vibration monitoring can be performed during normal operation of the coating apparatus. However, it is also possible that vibration analysis is conducted during specific measurement processes outside of normal coating operations. For this purpose, a control unit can be provided to control the coating apparatus according to a predetermined measurement process. Then, vibration sensors detect the vibration of the coating apparatus during the measurement process, and the evaluation unit evaluates the detected vibration signals to detect operational faults.

[0053] For example, during the measurement process, the control unit can control the painting robot to a specific robot position for vibration measurement, thereby enabling or simplifying meaningful vibration analysis.

[0054] Furthermore, within the scope of this invention, the control unit may control the rotating atomizer to perform vibration measurement at a specific rotational speed outside the resonant frequency range during the measurement process.

[0055] However, in another scenario, the control unit can also specifically drive the rotating atomizer to a rotation speed that matches the resonant frequency during the measurement process for vibration measurement.

[0056] Furthermore, the control unit can control the rotating atomizer to continuously perform vibration measurements at increasingly higher speeds during the measurement process, thereby performing vibration measurements at various speeds in each case. Additionally, within the scope of this invention, the control unit can control the rotating atomizer at different speeds during the measurement process, these speeds traversing a predetermined speed range. The evaluation unit can then determine the actual value of the natural frequency of the faulty component within the speed range during the measurement process and compare the determined actual value with a predetermined target value of the natural frequency to detect operational faults.

[0057] It should also be mentioned that, within the scope of this invention, a single vibration sensor may be sufficient to detect and distinguish different operational faults on different vulnerable components of the spraying apparatus. However, within the scope of this invention, it is also possible for the spraying apparatus to have multiple vibration sensors.

[0058] In principle, within the scope of this invention, it is conceivable to evaluate vibration signals in the time domain and / or frequency domain. For monitoring purposes, in addition to the “intensity” of the vibration event (e.g., in the form of vibration characteristics, such as amplitude, root mean square value, etc.), its time characteristics (e.g., duration, instantaneity, or periodicity) and / or its frequency characteristics (e.g., the frequency components contained therein, frequency-dependent “intensity”) can be considered.

[0059] It should also be mentioned that different procedures for identifying errors or malfunctions are made possible by spraying equipment (such as coating equipment), which will be briefly described below:

[0060] • Procedure 1: The spraying device (e.g., coating equipment) operates in normal process mode, meaning that many or all parts of the device may be operating simultaneously. Therefore, the vibration signal essentially contains a large amount of vibration information from various sources (e.g., atomizers, motors, gearboxes, valves, shafts, etc.). The vibration sensor simultaneously "listens" to all possible faults and analyzes / identifies errors through "intelligent" evaluation, "isolating" individual errors from multiple vibration signals based on appropriate assessment.

[0061] • Procedure 2: The spraying device (e.g., coating equipment) is specifically operated within a certain measurement procedure, in which only individual components of the device are in operation (e.g., a fixed turbine speed of a stationary robot, a limited movement of the shaft of a non-rotating turbine, the switching of certain valves of a stationary device, or similar). Therefore, the vibration signal is dominated by vibration information, which can be precisely assigned to this specific measurement procedure; that is, the evaluation is specifically based on vibration information.

[0062] If no clear results related to the fault / error are found initially in "Procedure 1" above, "Procedure 2" above can be carried out as a follow-up investigation.

[0063] However, the aforementioned "Program 2" can also be performed as the sole procedure, alternating with the aforementioned "Program 1".

[0064] Furthermore, redundant monitoring can be performed within the scope of this invention: to assess faults, vibration assessments can be combined with other assessment results, such as those from other sensors (pressure, current, voltage, speed, torque, force, etc.). In practice, painting devices (e.g., coating equipment, robots) typically provide a large number of analytical and sensor results, all of which can be considered in redundant monitoring. In this case, multiple vibration sensors at different locations are also conceivable.

[0065] Furthermore, artificial intelligence (AI) can also be used in the context of analysis to derive evaluation results from the whole of these many different signals.

[0066] Furthermore, this invention allows for the comparison of multiple robots within a robot unit, on a painting line, or within a painting equipment. This makes it possible to identify robots that are particularly prone to failure (“bad apples”).

[0067] Furthermore, this invention is also applicable to so-called "predictive maintenance," which involves initiating maintenance measures based on an assessment of vibration signals, independent of fixed maintenance intervals. Even so-called positive changes in vibration behavior (e.g., a decrease in vibration characteristic values ​​compared to previous measurements) may indicate unfavorable developments, as this is indicated in wear / aging processes. In this case, the change itself is significant, regardless of the direction in which it occurs. This is then evaluated by "artificial intelligence." Generally, for the evaluation, (absolute) vibration characteristics and associated limits (e.g., vibration intensity due to imbalance) as well as (relative) changes in vibration behavior or characteristics (e.g., over time, compared to previous measurements, etc.) can be taken into account.

[0068] Furthermore, it should be mentioned that this invention does not only claim protection for the aforementioned spraying apparatus. Rather, this invention also claims protection for the corresponding operating method. The various process steps of the operating method according to the invention are already apparent in the above description, therefore, a separate description of each process step is unnecessary.

[0069] Other advantageous further embodiments of the invention are pointed out in the dependent claims, or explained in more detail below together with the description of preferred embodiments of the invention and with reference to the accompanying drawings. Attached Figure Description

[0070] Figure 1 A schematic diagram of a painting robot with a rotary atomizer according to the present invention is shown, and operational faults can be detected through vibration analysis;

[0071] Figure 2 A perspective view of the painting robot is shown;

[0072] Figure 3 This diagram illustrates the calculation of vibration characteristic values ​​by the sensor electronics in the vibration sensor.

[0073] Figure 4 A schematic diagram showing the microprocessor calculating vibration characteristic values ​​in the evaluation unit is shown;

[0074] Figure 5 A schematic diagram illustrating the vibration behavior of a rotary atomizer under unbalanced conditions is shown.

[0075] Figure 6 A schematic diagram illustrating the vibrational behavior of a rotary atomizer after an impact is shown.

[0076] Figure 7 This is a flowchart illustrating the operation method according to the present invention;

[0077] Figure 8 It shows that according to Figure 7 A variant of the flowchart;

[0078] Figure 9 It shows that according to Figure 6 The flowchart was modified to illustrate vibration events in the valve circuit.

[0079] Figure 10 A flowchart illustrating a variation of the method of operation according to the present invention is shown;

[0080] Figure 11 A flowchart of another variation of the operating method according to the invention is shown, in which it is possible to specifically switch to the measurement process in order to diagnose operational malfunctions. Detailed Implementation

[0081] Figure 1 and Figure 2Various representations of a painting robot 1 according to the invention are shown, which is essentially a conventional design. Thus, the painting robot 1 first has a fixed robot base 2 that supports a pivotable robot component 3, which in this embodiment can pivot about a vertical axis of rotation. It should be noted here that the painting robot 1 can also have a movable robot base, allowing the painting robot 1 to move along a traversal track. The pivotable robot component 3 also carries a proximal robotic arm 4, which, according to common technical terminology in the robotics field, is also referred to as "arm 1". The proximal robotic arm 4 is divided here into two arm portions 5 and 6, which can rotate relative to each other. The proximal robotic arm 4, in turn, carries a distal robotic arm 7, wherein a multi-axis robotic hand shaft 8 is mounted at the end of the distal robotic arm 7. The robotic hand shaft 8, in turn, carries a rotary atomizer 9 as an application device, wherein the rotary atomizer 9... Figure 2 For simplicity, it is not shown.

[0082] The rotary atomizer 9 can generally adopt a conventional design, which includes a compressed air turbine 10 with a bearing 11, which rotates the bell cup 12 during operation.

[0083] In the conventional approach, the painting robot 1 has an electrostatic spraying agent feeding system, and therefore includes a high-voltage zone 13 and a grounded explosion-proof zone 14.

[0084] In the high-pressure zone 13 of the painting robot 1, in addition to the rotary atomizer 9, there is also a metering pump 15 of the painting robot 1, as well as a motor 16, a gearbox 17 and a bearing 18.

[0085] The motor 19, gearbox 20, and bearing 21 of the painting robot 1 are also located in the electrical connection area 14.

[0086] Furthermore, the painting robot 1 includes valves, such as those contained in the rotary atomizer 9 and the metering pump 15, although these valves are not shown for simplicity. Within the scope of this invention, malfunctions of these valves can also be detected.

[0087] In addition, vibration sensor 22 is also located in electrical contact area 14. It detects the mechanical vibration of the aforementioned components of the painting robot 1 and generates a corresponding vibration signal, which is sent to evaluation unit 23. Then, evaluation unit 23 analyzes the vibration signal to detect operational faults.

[0088] On the one hand, the evaluation unit 23 can thus identify the faulty component. Therefore, by analyzing the vibration signal, the evaluation unit 23 can distinguish whether one of the motors 16 in the high-voltage zone 13 is being interfered with, or whether one of the motors 19 in the electrical connection zone 14 is being interfered with, to give just one example.

[0089] However, on the other hand, the evaluation unit 23 can also identify the type of operational fault through vibration analysis. Therefore, the evaluation unit 23 can distinguish between different types of operational faults.

[0090] In this embodiment, the vibration sensor 22 is arranged in the distal robotic arm 7. However, it is also possible for the vibration sensor 22 to be arranged, for example, in the proximal robotic arm 4, in the pivotable robot component 3, or in the robot base 2. However, as the distance between the rotary atomizer 9 and the vibration sensor 22 increases, it becomes increasingly difficult to determine potential operational malfunctions of the rotary atomizer 9 by evaluating the vibration signal. This is due to the vibration transmission behavior within the painting robot 1, as well as the damping of mechanical vibrations along the route from the rotary atomizer 9 to the vibration sensor 22. Therefore, the vibration sensor 22 should not be installed too far from the rotary atomizer 9 to avoid making signal evaluation more difficult. However, arranging the vibration sensor 22 in a central position allows vibration events from components, such as the robotic arm, component, or rotary atomizer 9, at different locations to be detected centrally. Advantageously, the good transmission characteristics of the robotic arm are utilized.

[0091] Figure 3 This diagram illustrates the signal evaluation process of vibration sensor 22. Here, sensor electronics 24 are integrated into vibration sensor 22. This sensor electronics calculates vibration characteristic values ​​from the vibration signal, such as the effective value of the vibration signal, distortion coefficient, or crest coefficient. For this purpose, the time-dependent vibration signal is first decomposed into frequency components, for example, by a fast Fourier transform, and filtered if necessary. Then, the vibration characteristic values ​​are sent to evaluation unit 23 for signal evaluation.

[0092] Figure 4 It shows the Figure 3 The modification involves the vibration characteristic values ​​being calculated by the microprocessor 25 integrated in the evaluation unit 23.

[0093] Figure 5 This is a schematic diagram illustrating the measurable intensity of vibration characteristics caused by the imbalance U of the rotary atomizer, where the imbalance U may increase during operation, for example due to collisions between the rotary atomizer 9 and the room boundary (e.g., the wall of the painting chamber), as well as due to normal component wear. However, more generally, the imbalance may also decrease for various reasons.

[0094] The first characteristic curve 26 shows the increase in imbalance U at a relatively low speed n1 of the rotary atomizer 9. At this low speed n1, if the vibration characteristic value S exceeds a relatively small limit value S... MAX1 This will lead to operational malfunctions.

[0095] On the other hand, the second characteristic curve 27 shows the increased imbalance U at relatively high velocities n2. Here, when the vibration characteristic value S exceeds a large limit value S... MAX2 When this happens, operational malfunctions will occur.

[0096] The different curves 26 and 27 shown are not necessarily caused by higher or lower speeds. The cause could be, for example, the frequency-dependent transmission behavior of the robotic arm or other reasons.

[0097] In text and Figure 5 The description states that speed n1 is relatively low, and speed n2 is relatively high, with a relatively small limit value used for low speed n1 and a larger limit value used for high speed n2. However, this is only to be understood as a possible example. Generally, the following applies: even if a higher speed results in a higher excitation force (due to imbalance), this does not necessarily lead to a higher vibration intensity at the measurement point. For example, if the vibration transmission from the excitation force to the measurement point is correspondingly "worse" at higher speeds (higher frequencies) than at lower speeds (lower frequencies), then no. Or, to put it another way: at the measurement point, the vibration intensity at lower speeds may also be higher than the vibration intensity at higher speeds (i.e., exactly the opposite of what is shown / described). Then, for example, the limit value used for low speeds will be higher than the limit value used for high speeds.

[0098] Therefore, the decisive general statement is that at different velocities n1 and n2, there will generally be different vibration intensities (or curves) at the measurement point. Therefore, the limiting value must be "suitable" for the velocity.

[0099] For example, measurements / assessments performed at two (significantly) different speeds are also a form of redundant monitoring.

[0100] Figure 6 Vibration diagrams are shown in the area where the painting robot collides with the room boundary (e.g., the wall of the painting chamber). The collision occurs at time t = t1, manifested as two distinct vibration events 28 and 29.

[0101] At the collision time t = t1, vibration event 28 occurs first, which manifests as vibration exceeding the predetermined limit value A. MAX However, according to another example, a vibration event can also be expressed by the fact that the vibration is below a predetermined limit value.

[0102] Another vibration event 29 occurs after the actual collision, manifested in the specific embodiment as the vibration behavior subsequently being altered and amplified.

[0103] Figure 7 A flowchart illustrating the operation method according to the present invention is shown.

[0104] In the first step S1, the spraying device is controlled according to a predetermined measurement process. Here, for example, the robot position of the spraying robot can be predetermined. Furthermore, it is possible that the measurement process specifies a certain rotational speed of the rotary atomizer. Alternatively, it is also possible that some parts of the spraying device are operational during the measurement process, while other parts are not. Additionally, the measurement process may be specified that, as part of the measurement process, when the rotary atomizer is not rotating, only a certain robot axis is moved, so as to determine, for example, damage to the motor and / or gearbox.

[0105] During the measurement process, the vibration is then measured by a vibration sensor in step S2.

[0106] In step S3, the vibration characteristic value is then calculated from the vibration signal.

[0107] In step S4, operational faults are diagnosed by identifying the affected component and determining the type of fault.

[0108] Figure 8 It shows Figure 7 A variant of .

[0109] Here, the predetermined measurement process is also controlled in step S1, and the rotary atomizer runs through a certain speed range during the measurement process.

[0110] In step S2, the natural frequency of the rotary atomizer within the speed range is determined.

[0111] In another step S3, the determined natural frequency is compared with a predetermined natural frequency that occurs in a fault-free rotary atomizer.

[0112] In step S7, possible operational faults are diagnosed based on the comparison results.

[0113] Figure 9 It shows Figure 6 The diagram is a variation to illustrate oscillation events in the valve circuit of a valve. This valve can be any valve in a spraying system, such as a paint valve, solvent valve, pulse air valve, or air rectifier valve, to name just a few examples.

[0114] The graph plots time t on the X-axis and vibration characteristic value S on the Y-axis, which is calculated from the recorded vibration signal.

[0115] For example, the vibration parameter S can be the root mean square value of the vibration signal, the maximum value of the vibration signal, the first-order amplitude of the vibration signal, the higher-order amplitude of the vibration signal, the distortion coefficient of the vibration signal, or the crest coefficient of the vibration signal, to give just a few examples.

[0116] Furthermore, during the switching operation, an oscillation event 30 is shown in the figure, which causes the oscillation characteristic value S to exceed a predetermined maximum value S. MAX The indicator valve has malfunctioned.

[0117] Based on reference measurements taken during a complete valve switching operation, valve failure can also be identified by the absence of oscillation events (30°C) or the failure to exceed the maximum value (S). MAX To give instructions.

[0118] The following will describe according to Figure 10 The flowchart illustrates a variation of the operating method according to the present invention.

[0119] In the first step S1, the rotating atomizer is controlled to rotate at a specific measurement speed. This measurement speed can optionally be outside the resonance range or coincide with the resonance frequency. Therefore, the rotating atomizer can be controlled to avoid resonance or specifically to induce resonance.

[0120] In the second step S2, three separate signals are measured in three spatial directions (X, Y, Z) using a triaxial sensor. These separate signals are vibration signals in the three spatial directions (X, Y, Z).

[0121] In the next step S3, the three individual signals are set to be bandpass filtered at the center frequency corresponding to the measurement speed of the rotary atomizer.

[0122] In the next step S4, the individual signals are processed to form the overall signal. For example, the time process of the vector amplitude ("length of the track arrow") can be calculated from the three individual signals.

[0123] In the next step S5, vibration characteristic values, such as RMS values, are calculated from the overall signal.

[0124] In the final step S6, as described above, the fault is diagnosed based on the vibration characteristic values.

[0125] The following will describe according to Figure 11 The flowchart illustrates a variation of the operating method according to the present invention.

[0126] In the first step S1, the spraying device operates in a normal spraying process, meaning that all components (such as the rotary atomizer, metering pump, motor, electrostatic spraying agent feeding system, etc.) are in working condition, and the components are being sprayed. Therefore, the spraying process is a normal operation of the spraying device to coat the components.

[0127] In this normal spraying process, vibration signals are measured and evaluated in a separate step S2 to diagnose operational malfunctions, as described in detail above.

[0128] In the next step, S3, it is checked whether the evaluation of the vibration signal leads to a clear diagnostic result. A clear diagnostic result could be, for example, that no operational fault was detected. However, it is also possible that an operational fault was detected, but it can be clearly specified which part of the spraying apparatus the fault occurred in and what type of operational fault it was. In this case, the operation of the spraying apparatus can continue in the normal spraying process, or an error message can be generated.

[0129] However, during normal spraying, situations may arise where no clear diagnostic results can be detected. This may be due to vibrations from multiple components of the spraying unit, making it impossible to isolate and identify operational faults given the multiple different vibrations from different components. In this case, step S4 switches from the spraying process to a separate measurement process. During this measurement process, not all components of the spraying unit are operational, but only individual components, or even just one component, are operational.

[0130] In another step S5, the vibration signal is measured and evaluated again to identify operational faults.

[0131] During the measurement process, it is easier to identify operational faults because only a few parts are working, and correspondingly fewer vibration signals will appear, making signal evaluation much easier.

[0132] Once the operational malfunction has been identified, the spraying process can be resumed, which is not shown here for the sake of simplicity.

[0133] This invention is not limited to the preferred embodiments described above. Instead, numerous variations and modifications are possible, which also utilize the concepts of this invention and are therefore within its scope. In particular, this invention also claims protection for the subject matter and features of dependent claims independent of the claims mentioned in each example, and especially not including the features of the main claim. Therefore, this invention is not limited to such variations in which the evaluation unit distinguishes different operational faults from each other and can also diagnose different components prone to failure. Therefore, this invention also claims protection for other aspects of this invention independent of the technical teachings of the main claim.

[0134] List of reference numerals

[0135] 1. Painting Robot

[0136] 2. Robot base

[0137] 3 Pivotable Robotic Components

[0138] 4. Proximal robotic arm (arm 1)

[0139] 5 and 6: Arm section of the proximal robotic arm

[0140] 7. Remote robotic arm (arm)

[0141] 8 Robotic Handshafts

[0142] 9. Rotary atomizer

[0143] 10 Compressed air turbine for driving rotary atomizers

[0144] 11. Bearings in a rotary atomizer

[0145] 12-rotary atomizer bell cup

[0146] High-voltage area of ​​13 painting robots

[0147] 14 Grounding Explosion-proof Room

[0148] 15 Metering pumps for metering paint

[0149] 16 Motors for driving the axes of painting robots in high-pressure areas

[0150] Gearboxes for each robot axis in the 17 high-voltage zone

[0151] 18 painting robots in the high-pressure area bearings

[0152] 19 Motors for driving the axes of spraying robots in the contact area

[0153] Gearboxes for each robot axis in the 20-connection area

[0154] 21 painting robots are in the bearing area.

[0155] 22 vibration sensors

[0156] 23 assessment units

[0157] 24. Sensor electronics in a vibration sensor used to calculate vibration characteristic values.

[0158] The microprocessor in the 25 evaluation unit is used to calculate vibration characteristic values.

[0159] 26. Unbalanced characteristic curve at low speed

[0160] 27 Unbalanced characteristic curve at high speed

[0161] Vibration events during the 28th collision

[0162] 29 Vibration events after the collision

[0163] Oscillation event at valve 30

Claims

1. A spraying apparatus (1) for spraying components with a spraying agent, comprising: a) Multiple components (9-12, 15-18, 19-22) are prone to failure and may malfunction during operation of the spraying device (1); b) At least one vibration sensor (22) for detecting mechanical vibrations in the spraying apparatus (1) and converting them into vibration signals, which can be evaluated in terms of control technology based on the detected mechanical vibrations; and c) Evaluation unit (23), which is used to evaluate the vibration signal from the at least one vibration sensor (22) and diagnose the operational failure of one of the faulty components (9-12, 15-18, 19-22) of the spraying device (1) based on the vibration signal. Among them, the evaluation unit (23) c1) Calculate and evaluate at least one vibration characteristic value from the vibration signal. c) Monitor the vibration characteristic values ​​during the operation of the spraying device (1), and By evaluating the vibration signal of the vibration sensor (22), various operational faults of the various components (9-12, 15-18, 19-22) of the spraying device (1) that are prone to failure are diagnosed. Its features are, d) The evaluation unit (23) compares the vibration characteristic values ​​with the predetermined aging behavior of a specific component; and e) If the comparison of the vibration characteristic value with the predetermined aging behavior indicates that one of the faulty components (9-12, 15-18, 19-22) needs to be maintained or replaced due to wear, the evaluation unit (23) generates a first warning signal.

2. The spraying apparatus (1) according to claim 1, characterized in that, The spraying device is a painting robot that applies paint to the body parts of motor vehicles.

3. The spraying device (1) according to claim 1, characterized in that, The components (9-12, 15-18, 19-22) in the spraying device (1) that are prone to malfunction and whose operational faults are detected include multiple of the following components (9-12, 15-18, 19-22): a) A painting robot with multiple robot axes; b) An application device (9) for applying the spraying agent, wherein the application device (9) is guided by the spraying robot; c) The compressed air turbine (10) in the application device (9); d) Bell cup (12), which is mounted on the turbine shaft of the rotary atomizer (9); e) Metering pump (15), which is used to meter the spraying agent to the application device (9); f) At least one motor (16, 19) for driving one of the robot axes of the painting robot; g) at least one gearbox (17, 20) driven by one of the motors (16, 19) and acting on one of the robot axes; h) At least one bearing (18, 21) for rotatably supporting a component of the spraying device (1); i) Valves that can be controlled electrically or pneumatically.

4. The spraying apparatus (1) according to claim 3, characterized in that, The painting robot has a serial robot kinematic mechanism and / or at least six robot axes.

5. The spraying device (1) according to claim 3, characterized in that, The painting robot has the following features: a1) Robot base (2), which is fixed or movable; a2) A pivotable robot component (3) that is capable of pivoting relative to the robot base (2); a3) Proximal robotic arm (4) which is capable of pivoting relative to the pivotable robotic component (3); a4) a distal robotic arm (7) which is pivotable relative to the proximal robotic arm (4); and / or a5) Robotic hand shaft (8), which is mounted on the remote robotic arm (7).

6. The spraying apparatus (1) according to claim 3, characterized in that, The application device (9) is a rotary atomizer with a rotatable bell cup (12).

7. The spraying apparatus (1) according to claim 6, characterized in that, The compressed air turbine (10) is used to drive the rotatable turbine shaft of the rotary atomizer.

8. The spraying apparatus (1) according to claim 3, characterized in that, The motors (16, 19) are electric motors.

9. The spraying apparatus (1) according to claim 3, characterized in that, The bearings (18, 21) are air bearings or roller bearings.

10. The spraying apparatus (1) according to claim 3, characterized in that, The valve that can be controlled electrically or pneumatically is i1) Spray valve used to control the flow of spray agent; i2) Rinse agent valve used to control the flow of rinsing agent; i3) A valve used to control airflow; i4) A valve for opening / closing the treatment section through which paint, rinsing agent / solvent, and / or compressed air flow alternately or in mixture.

11. The spraying apparatus (1) according to claim 3, characterized in that, a) The vibration sensor (22) is mounted on the spraying robot and away from the application device (9); b) Mechanical vibrations emitted from the application device (9) are transmitted via the spraying robot to the vibration sensor (22), the spraying robot having certain vibration transmission characteristics; and c) The evaluation unit (23) determines the operational failure of the application device (9) by evaluating the vibration signal and taking into account the vibration transmission characteristics of the spraying robot.

12. The spraying apparatus (1) according to claim 11, characterized in that, The vibration sensor (22) is mounted on the robot base, on a pivotable robot component, on the proximal manipulator, on the distal manipulator, or on the robot hand shaft.

13. The spraying apparatus (1) according to any one of claims 1 to 12, characterized in that, The evaluation unit (23) diagnoses and distinguishes the following operational faults of the spraying device (1) by evaluating the vibration signal of the vibration sensor (22): a) Imbalance of the bell cup (12) of the rotating atomizer (9); b) Imbalance of the parts that rotate together with the bell cup (12); c) Mechanical wear of bearings (18, 21); d) Gearbox oil leak or lack of gear oil (17, 20); e) Motor oil leak or lack of oil (16, 19). f) Assembly error; g) Failure of the metering pump drive shaft (15); h) Collisions between the painting robot and obstacles; i) Valve circuit failure and / or valve function failure; j) Gearbox damage; k) Motor damaged.

14. The spraying apparatus (1) according to claim 13, characterized in that, The component that rotates together with the bell cup (12) is the turbine shaft.

15. The spraying apparatus (1) according to claim 13, characterized in that, The assembly error is f1) Incorrect tightening torque of the fastening screws; or f2) The drive shaft is not assembled correctly.

16. The spraying apparatus (1) according to claim 13, characterized in that, The obstacle is either the room boundary or another painting robot.

17. The spraying apparatus (1) according to any one of claims 1 to 12, characterized in that, The vibration sensor (22) is a biaxial or triaxial accelerometer.

18. The spraying apparatus (1) according to any one of claims 1 to 12, characterized in that, a) The spraying device (1) includes an explosion-proof chamber (14); and b) The vibration sensor (22) is arranged inside the explosion-proof chamber (14).

19. The spraying apparatus (1) according to claim 18, characterized in that, The explosion-proof room (14) has an air purging system that conforms to technical standards IEC / EN 60079-11- Part 11, IEC / EN 60079-25- Part 25 and IEC / EN60079-14- Part 14.

20. The spraying apparatus (1) according to any one of claims 1 to 12, characterized in that, a) The spraying device (1) includes a spraying robot having at least six robot axes arranged in series kinematically one after another; b) Each robot axis has a housing-mounted axis driver; c) The vibration sensor (22) is arranged in the housing of the axis drive for the fourth, fifth or sixth robot axis.

21. The spraying apparatus (1) according to any one of claims 1 to 12, characterized in that, a) The spraying apparatus (1) includes an electrostatic spraying agent feeding system, and therefore includes a high-voltage zone (13) and an electrically connected zone (14); and b) The vibration sensor (22) is arranged in the electrical contact area (14).

22. The spraying apparatus (1) according to any one of claims 1 to 12, characterized in that, The evaluation unit (23) calculates and evaluates at least one of the following vibration characteristic values ​​from the vibration signal: a) The root mean square value of the vibration signal; b) The maximum value of the vibration signal; c) The first-order amplitude of the vibration signal; d) Higher-order amplitudes of the vibration signal; e) Distortion coefficient of the vibration signal; f) Crest coefficient of the vibration signal.

23. The spraying apparatus (1) according to claim 22, characterized in that, a) The at least one vibration characteristic value is calculated from the vibration signal by a sensor electronics (24) structurally integrated into the vibration sensor (22); or b) The at least one vibration characteristic value is calculated from the vibration signal by the evaluation unit (23), which is structurally separate from the vibration sensor (22); or c) The at least one vibration characteristic value is calculated by software running in a microprocessor (25) connected to the evaluation unit (23).

24. The spraying apparatus (1) according to claim 22, characterized in that, a) The evaluation unit (23) compares the at least one vibration characteristic value (S) with the limit value (S). MAX1 S MAX2 ) for comparison; b) If the at least one vibration characteristic value (S) exceeds or falls below the limit value (S) MAX1 S MAX2 The evaluation unit (23) then generates a second warning signal.

25. The spraying apparatus (1) according to claim 24, characterized in that, The second warning signal is indicated to the operator of the spraying device (1) in an optical and / or acoustic manner.

26. The spraying apparatus (1) according to claim 24, characterized in that, The first warning signal and / or the second warning signal are: a) A maintenance signal, indicating to the operator that maintenance is required; or b) Stop signal, indicating to the operator that the operation must be interrupted or automatically causing the operation to be interrupted.

27. The spraying apparatus (1) according to any one of claims 1 to 12, characterized in that, a) A control unit is provided, which controls the spraying device (1) to perform vibration measurement according to a predetermined measurement process; b) The at least one vibration sensor (22) measures the vibration of the spraying device (1) during the measurement process; and c) The evaluation unit (23) evaluates the vibration signal detected during the measurement process.

28. The spraying apparatus (1) according to claim 27, characterized in that, a) The control unit controls the painting robot to enter a specific robot position to perform vibration measurements during the measurement process; and / or b) The control unit controls the spraying robot to perform vibration measurements according to a predetermined motion pattern during the measurement process; and / or c) The control unit controls the rotating atomizer (9) at a specific rotation speed during the measurement process to perform vibration measurement, the specific rotation speed being outside the resonant frequency range; and / or d) The control unit controls the rotary atomizer (9) to continuously perform vibration measurements at increasingly higher speeds during the measurement process, wherein vibration measurements are performed at each speed.

29. The spraying apparatus (1) according to claim 27, characterized in that, a) The control unit controls the rotary atomizer (9) at different speeds traversing a speed range during the measurement process; b) The evaluation unit (23) determines the actual value of the natural frequency of the faulty component within the speed range during the measurement process by evaluating the vibration signal; and c) The evaluation unit (23) compares the actual value of the natural frequency with the expected value of the predetermined natural frequency to detect operational faults.

30. The spraying apparatus (1) according to claim 27, characterized in that, a) The control unit controls the spraying device (1) according to the spraying process, during which multiple or all components of the spraying device (1) are in operation, and the spraying device (1) sprays the components with a spraying agent. b) The at least one vibration sensor (22) measures the vibration of the spraying apparatus (1) during the spraying process; and c) The evaluation unit (23) evaluates the vibration signals detected during the spraying process to identify operational malfunctions.

31. The spraying apparatus according to claim 30, characterized in that, a) During the measurement process, not all components of the spraying device (1) are in operation, or only a single component of the spraying device (1) is in operation; and b) The control unit will only initiate the measurement process if an operational fault cannot be clearly identified during the spraying process.

32. The spraying apparatus (1) according to any one of claims 1 to 12, characterized in that, The at least one vibration sensor (22) is the only vibration sensor (22) of the spraying device (1).

33. A method of operating the spraying apparatus (1) according to any one of claims 1 to 32 for spraying components with a spraying agent, comprising the following steps: a) A plurality of faulty components (9-12, 15-18, 19-22) of the spraying device (1) are operated, wherein these components (9-12, 15-18, 19-22) are prone to malfunction during operation of the spraying device (1); b) Measure the mechanical vibration of the spraying device (1) using a vibration sensor (22) and generate a vibration signal corresponding to the detected mechanical vibration; and c) Evaluate the vibration signal of the vibration sensor (22) using the evaluation unit (23) and diagnose operational malfunctions of one of the faulty components (9-12, 15-18, 19-22) of the spraying device (1) based on the vibration signal. Its features are, d) The evaluation unit (23) diagnoses various operational faults of various faulty components (9-12, 15-18, 19-22) of the spraying device (1) by evaluating the vibration signal of the vibration sensor (22).

34. The operating method according to claim 33, characterized in that, The spraying device is a painting robot that applies paint to the body parts of motor vehicles.

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