Monitoring device for painting machine, control device for robot system, and control method thereof

Abstract

This invention relates to a monitoring device for a coating machine, a control device for a robot system, and a control method for a robot system. The invention is used to detect the installation status of a bell cup in a coating machine. The monitoring device (10) of the coating machine (3) includes a rotary atomizing coating machine (3), an electro-proportional valve (41), and a controller (21). The rotary atomizing coating machine (3) coats a workpiece (9) by rotating a bell cup (33) mounted detachably on the top of a shaft (313) of a pneumatic motor (31) while supplying paint to the bell cup via a feed pipe (34). The electro-proportional valve (41) supplies air to the pneumatic motor. The controller (21) outputs a start command to the electro-proportional valve to start the pneumatic motor and detects whether the bell cup is installed on the shaft based on specific parameters related to the operation of the pneumatic motor at start-up.

Description

Technical Field

[0001] This invention relates to a monitoring device for a coating machine, a control device for a robot system, and a control method for a robot system. Background Technology

[0002] Japanese Patent No. 6804533 discloses a state determination device for a conventional coating apparatus. In a coating apparatus including a rotary atomizing head driven by a pneumatic motor, the state determination device detects the whirl of the rotary atomizing head by detecting vibrations of the coating apparatus. Whirl occurs when the rotary atomizing head is eccentrically mounted relative to the shaft of the pneumatic motor. It should be noted that the rotary atomizing head is also called a bell-shaped cup.

[0003] Rotary atomizing coating machines, such as those used in existing coating systems and supported by the arm of a robot, are used to coat workpieces. Summary of the Invention

[0004] The technical problem that the invention aims to solve During the preparation process before the robot performs the painting of the workpiece, there is sometimes a confirmation operation to check the paint supply of the painting machine. In this confirmation operation, the operator confirms that the amount of paint corresponding to the paint spraying instruction is being sprayed through the feed pipe.

[0005] In rotary atomizing coating machines, the bell cup can be detached from the top of the pneumatic motor shaft. During verification operation, the operator detaches the bell cup from the top of the pneumatic motor shaft, allowing paint to be sprayed out without rotating the pneumatic motor.

[0006] If the pneumatic motor is rotated with the bell cup removed, the paint will scatter. When the paint is sprayed with the bell cup mounted on the top of the shaft, if the pneumatic motor is not rotated, the paint will be bounced off the bell cup and flow back towards the pneumatic motor.

[0007] By performing paint spraying without rotating the pneumatic motor while the bell cup is removed, the operator can accurately determine the amount of paint sprayed from the top of the feed pipe.

[0008] After confirming the task and before the robot coats the workpiece, the operator reinstalls the bell cup onto the pneumatic motor shaft. If the pneumatic motor rotates with the bell cup removed, the paint will splatter as described above, making it impossible to coat the workpiece.

[0009] However, there have been instances where operators have forgotten to reinstall the bell cup after confirming the operation.

[0010] Currently, operators visually inspect the installation of bell cups on each robot individually to prevent any cups from being missed. However, since the robots are located within an explosion-proof area, operators must inspect the installation from outside the area. This inspection from a distance is difficult. Furthermore, depending on the robot's location, it can sometimes be difficult to visually inspect the coating machine from outside the explosion-proof area.

[0011] Technical solutions for solving technical problems The technology disclosed herein relates to a monitoring device for a coating machine. The monitoring device includes a rotary atomizing coating machine, an electro-proportional valve, and a controller. The rotary atomizing coating machine coats a workpiece by supplying paint to a bell-shaped cup (detachably mounted on the shaft of a pneumatic motor) via a feed pipe while rotating the bell-shaped cup. The electro-proportional valve supplies air to the pneumatic motor. The controller outputs a start command to the electro-proportional valve to activate the pneumatic motor and detects whether the bell-shaped cup is mounted on the shaft based on specific parameters related to the operation of the pneumatic motor at start-up.

[0012] Invention Effects In the monitoring device of the coating machine, the controller detects whether the bell cup has been installed on the shaft of the pneumatic motor based on specific parameters related to the operation of the pneumatic motor when it is started. Even without visual confirmation, the operator can confirm the installation status of the bell cup based on the controller's detection results. Attached Figure Description

[0013] Figure 1 This is a block diagram of the control device for a robot system, which includes a monitoring device for the painting machine.

[0014] Figure 2 This refers to the control panel.

[0015] Figure 3 This is a cross-sectional view of a rotary atomizing coating machine.

[0016] Figure 4 This shows the difference in the speed change of the pneumatic motor during startup caused by whether or not a bell cup is installed.

[0017] Figure 5 This is a flowchart illustrating the steps involved in confirming the installation of the bell-shaped cup.

[0018] Symbol Explanation 1 – Robot system; 10 – Monitoring device; 100 – Control device; 2 – Robot; 21 – Robot controller; 23 – Operation panel; 3 – Coating machine; 31 – Pneumatic motor; 313 – Shaft; 33 – Bell cup; 34 – Feed pipe; 41 – Electro-proportional valve; 51 – Fiber optic (sensor); 52 – Fiber optic amplifier (sensor); 53 – Pulse counter (sensor). Detailed Implementation

[0019] Hereinafter, embodiments of the monitoring device for the coating machine, the control device for the robot system, and the control method for the robot system will be described with reference to the accompanying drawings. The monitoring device for the coating machine, the control device for the robot system, and the control method for the robot system described herein are examples.

[0020] (Overall structure of the robot system) Figure 1 Robot system 1 is shown. Robot system 1 is a system in which robot 2 paints workpiece 9. Robot system 1 includes robot 2. It should be noted that robot 2 is not a necessary element of the monitoring device 10 of the painting machine 3.

[0021] Robot 2 is, for example, a vertical joint robot. It should be noted that Robot 2 is not limited to a vertical joint robot. The number of axes of Robot 2 is arbitrary. Robot 2 can be, for example, a six-axis robot. Robot 2 has an arm. The arm of Robot 2 supports the painting machine 3, which will be described later.

[0022] Robot 2 is positioned within the designated explosion-proof zone 20. Sometimes multiple robots 2 are positioned within the explosion-proof zone 20. Robot 2 is fixed to the floor or wall of the explosion-proof zone 20. Robot 2 is sometimes configured to move within the explosion-proof zone 20. Robot 2 has an explosion-proof structure.

[0023] Robot 2 can be used to paint various industrial products, such as automobiles, airplanes, or railway vehicles. It should be noted that workpiece 9 is not limited to the aforementioned automobiles, airplanes, or railway vehicles.

[0024] Robot controller 21 is connected to robot 2 via a wiring harness. Robot controller 21 is located outside the explosion-proof area 20. Robot controller 21 outputs motion commands to robot 2. Robot 2 performs actions according to the motion commands from robot controller 21 to paint workpiece 9. Robot 2 and robot controller 21 constitute the control device 100 of robot system 1.

[0025] The robot controller 21 can also be connected to one robot 2 and output motion commands to that robot 2. The robot controller 21 can also be connected to two or more robots 2 and output motion commands to each of the two or more robots 2.

[0026] The display device 22 and the control panel 23 are located outside the explosion-proof area 20. The display device 22 is electrically connected to the robot controller 21. The display device 22 displays signals corresponding to those received from the robot controller 21. It should be noted that the display device 22 is not an essential element of the monitoring device 10 of the painting machine 3 or the control device 100 of the robot system 1.

[0027] The control panel 23 is electrically connected to the robot controller 21. The control panel 23 is not an essential element of the monitoring device 10 of the painting machine 3.

[0028] Figure 2 Example of a control panel 23. The control panel has multiple push-button switches 231 and selection switches 232. For example... Figure 2 As shown in the enlarged view, the control panel 23 has a "paint supply" switch 231-1 for spraying paint from the coating machine 3 (described later) and a "paint stop" switch 231-2 for stopping paint spraying. The control panel 23 also has a "start pneumatic motor" switch 231-3 for driving the pneumatic motor 31 of the coating machine 3 and a "stop pneumatic motor" switch 231-4 for stopping the pneumatic motor 31.

[0029] The operator of robot 2 observes the display on display device 22 and operates the button switches 231 and selection switches 232 on operation panel 23. Operation panel 23 outputs operation signals corresponding to the operator's operations to robot controller 21. Robot controller 21 outputs action commands corresponding to the operation signals to robot 2.

[0030] (Structure of a painting machine) Robot system 1 includes a painting machine 3. The painting machine 3 is supported by the arm of robot 2 as described above.

[0031] Figure 3 The painting machine 3 is shown. The painting machine 3 is a rotary atomizing painting machine. The painting machine 3 has a pneumatic motor 31. The pneumatic motor 31 is housed in a housing 32.

[0032] The pneumatic motor 31 has a turbine 311. The turbine 311 is rotatably housed within the motor housing 312. Air is supplied from the electro-proportional valve 41 to rotate the turbine 311 (see also...). Figure 1 It should be noted that... Figure 1 It is not intended to indicate that the electro-proportional valve 41 supplies air only to the painting machine 3 of one robot 2.

[0033] The pneumatic motor 31 has a shaft 313. The shaft 313 is fixed to the turbine 311 and rotates together with the turbine 311. An air bearing 314 supports the shaft 313 and the shaft 313 is rotatable.

[0034] The coating machine 3 has a bell-shaped cup 33. The bell-shaped cup 33 is mounted on the top of the shaft 313 of the pneumatic motor 31. The bell-shaped cup 33 is, for example, fastened to a thread formed on the top of the shaft 313. Figure 3 As shown by the double-dotted line, the bell-shaped cup 33 is detachably mounted on the top of the shaft 313. It should be noted that the symbol 35 refers to the cover 35 that covers the top opening of the housing 32.

[0035] The bell-shaped cup 33 rotates together with the pneumatic motor 31. The rotating bell-shaped cup 33 uses centrifugal force to atomize the paint supplied through the feed pipe 34 (described later) and spray it onto the workpiece 9.

[0036] The coating machine 3 has a feed pipe 34. The feed pipe 34 is located inside the hollow shaft 313. The top end of the feed pipe 34 is connected to a bell cup 33. The feed pipe 34 feeds paint into the bell cup 33.

[0037] The base of the feed pipe 34 is connected to a trigger valve 341. The trigger valve 341 is used to switch between supplying paint to the feed pipe 34 and stopping the supply. The trigger valve 341 is switched by air actuation. Figure 1 As shown, trigger valve 341 is connected to paint supply source 42. Paint supply source 42 supplies paint to feed pipe 34. It should be noted that... Figure 1 This is not intended to imply that paint supply source 42 supplies paint only to the painting machine 3 of robot 2.

[0038] It should be noted that, Figure 3 The structure of the painting machine 3 is shown as an example. The robot system 1 is capable of using painting machines 3 with various known structures.

[0039] The coating machine 3 is connected to an optical fiber 51. The optical fiber 51 is connected to an encoder used to detect the rotation of the pneumatic motor 31. The optical fiber 51 transmits the on / off signal of the light generated by the encoder as... Figure 1 The signal is transmitted to fiber optic amplifier 52. Fiber optic amplifier 52 receives the optical signal from fiber optic 51 and outputs a pulse signal. It should be noted that... Figure 1 It is not intended to show that fiber optic 51 is connected to only one robot 2 painting machine 3.

[0040] The pulse counter 53 counts the pulse signals from the fiber optic amplifier 52, thereby converting the pulse signals into the rotational speed of the pneumatic motor 31. The robot controller 21 obtains the rotational speed of the pneumatic motor 31 based on the output of the pulse counter 53.

[0041] The robot controller 21 adjusts the speed of the pneumatic motor 31 to a target speed, for example, via PI control, based on the obtained rotational speed of the pneumatic motor 31. Specifically, the robot controller 21 outputs a pressure command to the electro-proportional valve 41 to adjust the rotational speed of the pneumatic motor 31 to the target speed. The electro-proportional valve 41 adjusts the pressure of the air supplied to the pneumatic motor 31 based on the pressure command from the robot controller 21. By adjusting the air pressure, the rotational speed of the pneumatic motor 31 is adjusted.

[0042] (Confirm the installation status of the bell-shaped cup) As described above, the bell-shaped cup 33 is mounted on the top of the shaft 313 of the pneumatic motor 31 in a detachable manner. During the preparation process before the robot 2 performs the painting of the workpiece 9, the bell-shaped cup 33 is sometimes removed from the painting machine 3.

[0043] The operator removes the bell cup 33 from the coating machine 3 and, without rotating the pneumatic motor 31, instructs the operator to spray paint via the control panel 23. This is an operation to confirm that the coating machine 3 is spraying paint corresponding to the indicated amount. By not rotating the pneumatic motor 31 during this operation, paint splatter is prevented, and the operator can confirm the amount of paint sprayed from the top of the feed pipe 34. Removing the bell cup 33 from the feed pipe 34 during this confirmation operation prevents the paint conveyed through the feed pipe 34 from being bounced back towards the pneumatic motor 31 by the non-rotating bell cup 33.

[0044] Before the robot 2 begins painting the workpiece 9, the operator reinstalls the bell cup 33, which has been removed from the painting machine 3, onto the top of the shaft 313 of the pneumatic motor 31. Without the bell cup 33 installed, if the pneumatic motor 31 is rotated to spray paint, the paint will scatter, and the robot 2 and the painting machine 3 will be unable to paint the workpiece 9.

[0045] The robot system 1 disclosed herein can confirm whether the bell cup 33 has been installed. The operator can confirm whether the bell cup 33 has been installed outside the explosion-proof area 20.

[0046] The robot system 1 includes a monitoring device 10 for the painting machine 3. For example... Figure 1 As shown, the monitoring device 10 has a detection unit 211. The detection unit 211 is a functional block in the robot controller 21. The detection unit 211 detects whether the bell cup 33 has been installed based on the change in the rotational speed of the pneumatic motor 31 when it is started and is in a stopped state.

[0047] Figure 4 The difference in the rotational speed of the pneumatic motor 31 during startup is shown due to whether or not the bell cup 33 is installed. Figure 4The horizontal axis represents the passage of time. The vertical axis represents the rotational speed of the pneumatic motor 31. As described above, the robot controller 21 can obtain the rotational speed of the pneumatic motor 31 based on the output of the pulse counter 53.

[0048] Figure 4 The solid line represents the change in rotational speed of the pneumatic motor 31 when the bell cup 33 is mounted on the shaft 313 of the pneumatic motor 31. After the pneumatic motor 31 starts, its rotational speed increases, exceeding the target speed and causing overshoot. Due to feedback control of the pneumatic motor 31 by the robot controller 21, the rotational speed of the pneumatic motor 31 then quickly converges to the target speed.

[0049] Figure 4 The dashed line represents the change in rotational speed of the pneumatic motor 31 when the bell cup 33 is not mounted on the shaft 313 of the pneumatic motor 31. Because the bell cup 33 is not mounted, the mass of the rotating body, in this case, the pneumatic motor 31 without the bell cup 33, is relatively small. After the pneumatic motor 31 starts, its rotational speed increases rapidly, and the overshoot of the pneumatic motor 31 becomes large. Since the feedback gain is set based on the state with the bell cup 33 mounted on the pneumatic motor 31, the rotational speed of the pneumatic motor 31 is difficult to converge to the target speed.

[0050] As an example, the detection unit 211 detects whether the bell cup 33 has been installed by comparing the time T1 and T2 (T1 < T2) from the start of the pneumatic motor 31 until its rotational speed exceeds the target speed with a preset threshold Tth. That is, if the measured time is longer than the threshold Tth, the detection unit 211 detects that the bell cup 33 has been installed on the pneumatic motor 31. If the measured time is shorter than the threshold Tth, the detection unit 211 detects that the bell cup 33 has not been installed on the pneumatic motor 31.

[0051] The monitoring device 10 of the painting machine 3 can also confirm whether the bell cup 33 has been installed based on the operator's actions. For example, as Figure 2 As shown, when the "Check Bell Cup" button 231-5 on the operation panel 23 is operated, the monitoring device 10 of the coating machine 3 confirms whether the bell cup 33 has been installed. The monitoring device 10 starts the pneumatic motor 31, which is in a stopped state, and detects the installation status of the bell cup 33 based on the change in the rotational speed of the pneumatic motor 31 during the start-up process.

[0052] The monitoring device 10 of the painting machine 3 can also automatically detect the installation status of the bell cup 33 when the operator performs the operation preparation operation of the robot 2 on the control panel 23. That is, the monitoring device 10 starts the pneumatic motor 31 which is in a stopped state, and detects the installation status of the bell cup 33 based on the change in the rotational speed of the pneumatic motor 31 during the start-up process.

[0053] (Interlocking function based on confirmation of bell-shaped cup installation) The control device 100 of the robot system 1 has an interlock function that prohibits specific operations of the operator based on the monitoring results of the monitoring device 10 of the painting machine 3.

[0054] The interlock function prevents paint from being sprayed if the pneumatic motor 31 is not started when the bell cup 33 is detected. As described above, this interlock function prevents paint from flowing back towards the pneumatic motor 31.

[0055] Another interlocking function is to prevent robot 2 from painting workpiece 9 if bell cup 33 is not installed. As mentioned above, this interlocking function prevents paint from scattering.

[0056] Figure 5 This is a flowchart illustrating the steps involved in confirming the installation of the bell-shaped cup 33. As described above, Figure 5 The flowchart begins when the operator operates the "Check Bell Cup" button 251-5 on the control panel 23, or when the operator prepares the robot 2 for operation.

[0057] In step S51 after the start, the robot controller 21 starts the pneumatic motor 31 via the electro-proportional valve 41. The robot controller 21 also measures the elapsed time from the start of the pneumatic motor 31.

[0058] In the next step S52, the robot controller 21 obtains the rotational speed of the pneumatic motor 31 measured by the encoder through the pulse counter 53.

[0059] In step S53, the robot controller 21 compares the rotational speed of the pneumatic motor 31 obtained in step S52 with the target rotational speed. Figure 5 The process repeats steps S52 and S53 until the speed of the pneumatic motor 31 reaches the target speed.

[0060] When the rotational speed of the pneumatic motor 31 exceeds the target rotational speed, the robot controller 21 ends the time measurement in step S54, and in the next step S55, compares the measured time T with a predetermined threshold Tth.

[0061] If the measured time T is shorter than Tth, the robot controller 21 detects that the bell cup 33 is not installed on the pneumatic motor 31. In step S56, the robot controller 21 prohibits the robot 2 from painting the workpiece 9. Specifically, the robot controller 21 displays the situation that the bell cup 33 is not installed on the pneumatic motor 31 on the display device 22. The operator can know that the bell cup 33 is not installed outside the explosion-proof area 20.

[0062] In step S56, even if the operator instructs the robot 2 to perform a painting action on the control panel 23, the robot controller 21 will invalidate the instruction and prevent the robot 2 from performing the painting action.

[0063] In step S56, when the operator operates "paint supply" on the control panel 23 instead of "start pneumatic motor," the robot controller 21 activates the paint spraying command. The painting machine 3 sprays paint. The operator can then confirm the amount of paint sprayed.

[0064] In step S55, if the measured time T is greater than or equal to Tth, the robot controller 21 detects that the bell cup 33 has been mounted on the pneumatic motor 31. The robot controller 21 displays this information, for example, on the display device 22.

[0065] In step S57, if the pneumatic motor 31 is not started, the robot controller 21 prohibits the paint spraying operation. Even if the operator operates "paint supply" on the control panel 23 without operating "start pneumatic motor", the robot controller 21 will invalidate the paint spraying command. The painting machine 3 will not spray paint. When the operator operates "start pneumatic motor" and then operates "paint supply", the robot controller 21 makes the paint spraying command valid. The painting machine 3 sprays paint.

[0066] In step S57, if the operator instructs the robot 2 to perform a painting action on the control panel 23, the robot controller 21 makes the instruction valid. The robot controller 21 then instructs the robot 2 to perform the painting action.

[0067] It should be noted that, Figure 5 The procedure shown for confirming the installation status is performed on all painting machines 3 of robots 2 located within the explosion-proof area 20.

[0068] (Function and Effect) The monitoring device 10 of the coating machine 3 detects whether the bell cup 33 has been installed on the shaft 313. The operator can also confirm the installation status of the bell cup 33 without visual inspection. By observing the display on the display device 22, the operator can confirm from outside the explosion-proof area 20 whether the bell cup 33 has been installed on the coating machine 3 supported by the robot 2. The operator can also confirm the installation status of the bell cup 33 for each of the multiple robots 2 on their respective coating machines 3.

[0069] The monitoring device 10 detects whether the bell cup 33 has been installed based on specific parameters related to the rotational speed of the pneumatic motor 31 when it starts. The monitoring device 10 is able to accurately detect the installation status of the bell cup 33.

[0070] More specifically, when the pneumatic motor 31 is started, the monitoring device 10 detects whether the bell cup 33 has been installed on the shaft 313 based on the time it takes for the pneumatic motor 31 to reach the target speed.

[0071] When the bell-shaped cup 33 is mounted on the shaft 313 of the pneumatic motor 31, the mass of the rotating body that rotates with the pneumatic motor 31 is relatively large. When the bell-shaped cup 33 is not mounted on the shaft 313 of the pneumatic motor 31, the mass of the rotating body that rotates with the pneumatic motor 31 is relatively small. When the pneumatic motor 31 starts, the time it takes for the speed of the pneumatic motor 31 to reach the target speed varies depending on the mass of the rotating body, therefore the monitoring device 10 can accurately detect the installation status of the bell-shaped cup 33.

[0072] With the bell-shaped cup 33 mounted on the shaft 313, the control device 100 of the robot system 1 disables the paint spraying command issued via the operation panel 23 when the pneumatic motor 31 is stopped. The robot controller 21 has an interlock function, thus preventing paint backflow in advance.

[0073] When the bell cup 33 is not mounted on the shaft 313, the control device 100 of the robot system 1 invalidates the painting action commands of the robot 2 issued via the operation panel 23. The robot controller 21 has an interlocking function, thus preventing paint splattering in advance.

[0074] When the bell cup 33 is not mounted on the shaft 313, the control device 100 of the robot system 1 allows paint spraying commands to be issued via the operation panel 23 while the pneumatic motor 31 is stopped. The operator can perform confirmation operations related to the sprayed paint, that is, can perform operations to confirm that the amount of paint corresponding to the paint spraying instruction has been sprayed through the feed pipe 34.

[0075] Because the control panel 23 has "Check Bell Cup" buttons 231-5, the operator can manually operate it to begin checking the installation status of the bell cup 33.

[0076] When the operator performs pre-operation preparation operations on the control panel 23, the control device 100 of the robot system 1 detects the installation status of the bell cup 33. Since the installation status of the bell cup 33 can be automatically confirmed during the pre-operation preparation operation, operator errors can be suppressed.

[0077] (Modified example) The detection unit 211 can detect the installation status of the bell cup 33 by means of a method based on the time it takes for the rotational speed of the pneumatic motor 31 to exceed the target rotational speed, and can also use various other detection methods.

[0078] like Figure 4 As shown, the detection unit 211 can, for example, detect whether the bell cup 33 has been installed after the pneumatic motor 31 is started, based on a comparison between the overshoot R1 and R2 (R1 > R2) of the pneumatic motor 31 exceeding the target speed and a preset threshold Rth. That is, if the overshoot is less than the threshold Rth, the detection unit 211 detects that the bell cup 33 has been installed on the pneumatic motor 31. If the overshoot is greater than the threshold Rth, the detection unit 211 detects that the bell cup 33 has not been installed on the pneumatic motor 31.

[0079] The detection unit 211 can also detect that the bell cup 33 has been installed based on the fact that the rotational speed of the pneumatic motor 31 is stable at the target rotational speed. For example, after a predetermined time has elapsed since the pneumatic motor 31 started, the difference between the rotational speed of the pneumatic motor 31 and the target rotational speed (e.g., referring to...) can be used to detect the installation of the bell cup 33. Figure 4 If d) is below a specified value, the detection unit 211 detects that the bell cup 33 is installed on the pneumatic motor 31. If the difference between the rotational speed of the pneumatic motor 31 and the target rotational speed exceeds a specified value, the detection unit 211 detects that the bell cup 33 is not installed on the pneumatic motor 31. It should be noted that the specified time from the start of startup can also be set based on the convergence time of the rotational speed in the feedback control.

[0080] Whether the rotational speed of the pneumatic motor 31 is stable at the target rotational speed can also be determined based on the integral of the absolute value of the difference between the rotational speed of the pneumatic motor 31 and the target rotational speed. It should be noted that the integral is equivalent to... Figure 4 The sum of the areas of the mesh portion is added. If the integral value is below a predetermined threshold, the detection unit 211 detects that the bell-shaped cup 33 is mounted on the pneumatic motor 31. If the integral value exceeds the predetermined threshold, the detection unit 211 detects that the bell-shaped cup 33 is not mounted on the pneumatic motor 31.

[0081] The detection unit 211 can also detect the installation status of the bell cup 33 based on changes in the pressure command output by the robot controller 21 to the electro-proportional valve 41. The pressure command output by the robot controller 21 changes accordingly with the rotational speed of the pneumatic motor 31. The unit detects changes in the pressure command to determine whether the bell cup 33 is installed. Figure 4 The speed change of the pneumatic motor 31 measured by the encoder shown is used as a reference. The detection unit 211 can detect the installation status of the bell cup 33 using the various detection methods based on the pressure command output by the robot controller 21.

[0082] All of the detection methods are effective under the feedback control of the rotational speed of the pneumatic motor 31 executed by the robot controller 21.

[0083] The detection unit 211 can also detect the installation status of the bell cup 33 even when the robot controller 21 is not performing feedback control. For example, the electro-proportional valve 41 can also supply air to the pneumatic motor 31 at a predetermined constant pressure when the pneumatic motor 31 is started. The detection unit 211 can detect whether the bell cup 33 is installed on the shaft 313 based on the rotational speed of the pneumatic motor 31 after a predetermined time from the start of the pneumatic motor 31. When the bell cup 33 is installed, the rotational speed of the pneumatic motor 31 after a predetermined time from the start of the pneumatic motor 31 is relatively low due to the large mass of the rotating body. When the bell cup 33 is not installed, the rotational speed of the pneumatic motor 31 after a predetermined time from the start of the pneumatic motor 31 is relatively high due to the small mass of the rotating body. The detection unit 211 can accurately detect the installation status of the bell cup 33.

[0084] The functionality of the elements disclosed in this specification can be implemented using one or more circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays), and / or conventional circuits. The functionality of the elements disclosed in this specification can also be implemented using one or more circuits or processing circuits, including combinations of general-purpose processors, special-purpose processors, integrated circuits, ASICs, FPGAs, and conventional circuits. One or more circuits or processing circuits can be programmed using one or more programs stored together or separately in one or more memories, or otherwise configured to perform the disclosed functions. Because a processor includes transistors and other circuitry, it is considered a processing circuit or circuit. A processor can also be a programmed processor that executes a program stored in memory. In this disclosure, a circuit, unit, or device is hardware that performs the listed functions individually or in combination with each other, or hardware programmed to perform the listed functions individually or in combination with each other. The hardware can be any hardware, as long as it is the hardware disclosed in this specification and programmed or configured to perform the listed functions.

[0085] A computer program, including computer instructions, is stored in memory. The computer instructions provide logic and routines that enable hardware to perform the methods disclosed in this specification. The hardware may include, for example, processing circuitry or circuitry. The computer program may be stored in a known format in a computer-readable storage medium, a computer program product, a memory device, a recording medium such as a CD-ROM or DVD, and / or the memory of FPGAs or ASICs.

[0086] (aspect) The above implementation methods are specific examples of the following aspects.

[0087] (First aspect) The first aspect relates to a monitoring device 10 for a coating machine 3, comprising a rotary atomizing coating machine 3, an electro-proportional valve 41, and a controller 21. The rotary atomizing coating machine 3 coats a workpiece 9 by rotating a bell-shaped cup 33, which is detachably mounted on the top of a shaft 313 of the pneumatic motor 31, using a pneumatic motor 31 to rotate the bell-shaped cup 33, while supplying paint to the bell-shaped cup 33 via a feed pipe 34. The electro-proportional valve 41 supplies air to the pneumatic motor 31. The controller 21 outputs a start command to the electro-proportional valve 41 to start the pneumatic motor 31 and detects whether the bell-shaped cup 33 is mounted on the shaft 313 based on specific parameters related to the operation of the pneumatic motor 31 at start-up.

[0088] The controller 21 detects whether the bell cup 33 has been installed on the shaft 313.

[0089] Specifically, controller 21 outputs a start command for pneumatic motor 31 to electro-proportional valve 41. Air is supplied to pneumatic motor 31, and pneumatic motor 31 starts.

[0090] The controller 21 detects whether the bell cup 33 has been mounted on the shaft 313 based on specific parameters related to the operation of the pneumatic motor 31 at startup. The monitoring device 10 of the coating machine 3 can accurately detect whether the bell cup 33 has been mounted on the shaft 313.

[0091] (Second aspect) The second aspect is based on the monitoring device 10 of the coating machine 3 described in the first aspect, which includes sensors 51, 52, and 53 for measuring the rotational speed of the pneumatic motor 31. The electro-proportional valve 41 adjusts the air supply to the pneumatic motor 31 based on the rotational speed of the pneumatic motor 31 measured by the sensors 51, 52, and 53, so that the rotational speed of the pneumatic motor 31 becomes the target rotational speed. The controller 21 detects whether the bell cup 33 has been installed on the shaft 313 based on the rotational speed of the pneumatic motor 31 measured by the sensors 51, 52, and 53.

[0092] Since the mass of the rotating body, including the pneumatic motor 31, changes depending on whether the bell cup 33 is installed, the rotational speed of the pneumatic motor 31 will vary over time when the pneumatic motor 31 is started, depending on whether the bell cup 33 is installed.

[0093] The monitoring device 10 of the painting machine 3 can accurately detect whether the bell cup 33 has been installed on the shaft 313 based on the rotational speed of the pneumatic motor 31.

[0094] (Third aspect) Thirdly, based on the monitoring device 10 of the coating machine 3 described in the second aspect, the controller 21 detects whether the bell cup 33 has been installed on the shaft 313 based on the time it takes for the rotational speed of the pneumatic motor 31 to reach the target rotational speed when the pneumatic motor 31 is started.

[0095] When a bell-shaped cup 33 is mounted on the shaft 313 of the pneumatic motor 31, the mass of the rotating body that rotates with the pneumatic motor 31 is relatively large. When the pneumatic motor 31 starts, the time it takes for the pneumatic motor 31 to reach the target speed is relatively long.

[0096] Without the bell cup 33 mounted on shaft 313, the mass of the rotating body that rotates together with the pneumatic motor 31 is relatively small. When the pneumatic motor 31 starts, the time it takes for the pneumatic motor 31 to reach the target speed is relatively short.

[0097] The controller 21 can accurately detect whether the bell cup 33 has been installed on the shaft 313 based on the time it takes for the pneumatic motor 31 to reach the target speed.

[0098] (Fourth aspect) Fourthly, based on the monitoring device 10 of the coating machine 3 described in the second aspect, the controller 21 detects whether the bell cup 33 has been installed on the shaft 313 when the pneumatic motor 31 is started, based on the overshoot of the rotational speed of the pneumatic motor 31 exceeding the target rotational speed.

[0099] When a bell-shaped cup 33 is mounted on the shaft 313, the overshoot of the pneumatic motor 31 is small because the mass of the rotating body that rotates together with the pneumatic motor 31 is large.

[0100] When the bell cup 33 is not installed on the shaft 313, the overshoot of the pneumatic motor 31 is large when it starts because the mass of the rotating body that rotates with the pneumatic motor 31 is small.

[0101] The controller 21 can accurately detect whether the bell cup 33 has been installed on the shaft 313 based on the overshoot when the pneumatic motor 31 starts.

[0102] (Fifth aspect) Fifthly, based on the monitoring device 10 of the coating machine 3 described in the second aspect, the controller 21 performs feedback control of the rotational speed of the pneumatic motor 31 based on the rotational speed of the pneumatic motor 31 measured by the sensors 51, 52, and 53. Based on the fact that the rotational speed of the pneumatic motor 31 is stable at the target rotational speed, the controller 21 detects that the bell cup 33 has been installed on the shaft 313.

[0103] In the speed feedback control of the pneumatic motor 31, the feedback gain is set based on the premise that a bell cup 33 is installed on the shaft 313.

[0104] With the bell-shaped cup 33 mounted on the shaft 313, the rotational speed of the pneumatic motor 31 quickly converges to the target speed and stabilizes after the pneumatic motor 31 is started, thanks to feedback control from the controller 21. It should be noted that the stabilization of the pneumatic motor 31's rotational speed at the target speed can also mean that, at a predetermined time point after the pneumatic motor 31 has started, the difference between the pneumatic motor 31's rotational speed and the target rotational speed is below a predetermined value.

[0105] Without the bell cup 33 installed on shaft 313, the mass of the rotating body that rotates with the pneumatic motor 31 is relatively small. Therefore, even if a specified time has elapsed since the pneumatic motor 31 started, the rotational speed of the pneumatic motor 31 will not stabilize at the target rotational speed. In other words, even at the point in time when the specified time has elapsed since the pneumatic motor 31 started, the difference between the rotational speed of the pneumatic motor 31 and the target rotational speed will exceed the specified value.

[0106] The controller 21 can accurately detect that the bell cup 33 has been installed on the shaft 313 based on the fact that the rotational speed of the pneumatic motor 31 is stable at the target rotational speed.

[0107] (Sixth aspect) In the sixth aspect, based on the monitoring device 10 of the coating machine 3 described in the fifth aspect, the controller 21 detects whether the bell cup 33 has been installed on the shaft 313 based on the integral of the absolute value of the difference between the rotational speed of the pneumatic motor 31 and the target rotational speed when the pneumatic motor 31 is started.

[0108] When the rotational speed of the pneumatic motor 31 converges to the target rotational speed, the integral value of the absolute value of the difference between the rotational speed of the pneumatic motor 31 and the target rotational speed is small. When the integral value is below a specified value, the controller 21 can detect that the bell cup 33 has been installed on the shaft 313.

[0109] If the speed of the pneumatic motor 31 does not converge to the target speed, the integral value of the absolute value of the difference between the speed of the pneumatic motor 31 and the target speed is large. If the integral value exceeds the specified value, the controller 21 can detect that the bell cup 33 is not installed on the shaft 313.

[0110] (Seventh aspect) In the seventh aspect, based on the monitoring device 10 of the coating machine 3 described in the second aspect, the electro-proportional valve 41 supplies air to the pneumatic motor 31 at a predetermined constant pressure when the pneumatic motor 31 is started, and the controller 21 detects whether the bell cup 33 has been installed on the shaft 313 based on the rotational speed of the pneumatic motor 31 after a predetermined time has elapsed since the start of the pneumatic motor 31.

[0111] When the bell cup 33 is mounted on the shaft 313, the rate of increase in the rotational speed of the pneumatic motor 31 is low because the mass of the rotating body that rotates together with the pneumatic motor 31 is relatively large. When the controller 21 supplies air to the pneumatic motor 31 at a specified constant pressure without feedback control, the rotational speed of the pneumatic motor 31 is low after a specified time has elapsed since the start of the pneumatic motor 31.

[0112] When the bell cup 33 is not installed on the shaft 313, the rate of increase in the rotational speed of the pneumatic motor 31 is higher because the mass of the rotating body that rotates with the pneumatic motor 31 is relatively small. In other words, when the controller 21 supplies air to the pneumatic motor 31 at a specified constant pressure, the rotational speed of the pneumatic motor 31 is higher after a specified time has elapsed since the start of the pneumatic motor 31.

[0113] The controller 21 can accurately detect whether the bell cup 33 has been installed on the shaft 313 based on the rotational speed of the pneumatic motor 31 after a specified time since the pneumatic motor 31 was started.

[0114] (Eighth aspect) The eighth aspect is based on the monitoring device 10 of the coating machine 3 described in any one of the first to seventh aspects, wherein the coating machine 3 is supported by the arm of the robot 2.

[0115] Robot 2 is sometimes located in an explosion-proof area. The monitoring device 10 of the coating machine 3 allows the operator to confirm from outside the explosion-proof area whether the bell cup 33 has been installed on the coating machine 3 supported by robot 2.

[0116] (Ninth aspect) The ninth aspect relates to a control device 100 for a robot system 1, comprising a robot 2, a rotary atomizing coating machine 3, an electro-proportional valve 41, a controller 21, and an operation panel 23. The rotary atomizing coating machine 3 is supported by the arm of the robot 2 and coats a workpiece 9 by supplying paint to a bell-shaped cup 33 (detachably mounted on the top of a shaft 313 of the pneumatic motor 31) via a feed pipe 34 while rotating the bell-shaped cup 33. The electro-proportional valve 41 supplies air to the pneumatic motor 31. The controller 21... The start command for starting the pneumatic motor 31 is output to the electro-proportional valve 41, and the bell cup 33 is detected as being mounted on the shaft 313 based on specific parameters related to the operation of the pneumatic motor 31 at start-up. The operation panel 23 outputs the operation commands for the robot 2 and the painting machine 3 corresponding to the operator's operation to the controller 21. If the bell cup 33 is mounted on the shaft 313, the controller 21 invalidates the paint spraying command issued via the operation panel 23 when the pneumatic motor 31 is stopped.

[0117] As described above, the controller 21 detects whether the bell cup 33 has been mounted on the shaft 313 based on specific parameters related to the operation of the pneumatic motor 31 when it is started.

[0118] If the bell cup 33 is installed on the shaft 313 and the paint is fed to the bell cup 33 through the feed pipe 34 while the pneumatic motor 31 is stopped, the paint may be bounced off the bell cup 33 and flow back towards the pneumatic motor 31.

[0119] The controller 21 disables paint spraying commands issued via the control panel 23 when the pneumatic motor 31 has stopped. The controller 21 has an interlock function, thus preventing paint backflow in advance.

[0120] (Tenth aspect) In the tenth aspect, based on the control device 100 of the robot system 1 described in the ninth aspect, when the bell cup 33 is not mounted on the shaft 313, the controller 21 invalidates the painting action command of the robot 2 issued via the operation disk 23.

[0121] If the bell cup 33 is not installed on the shaft 313, and the paint is fed through the feed pipe 34 while the pneumatic motor 31 is rotating, the paint will scatter and the painting machine 3 will be unable to paint the workpiece 9.

[0122] The controller 21 disables the painting action commands of the robot 2 issued via the control panel 23. The controller 21 has an interlock function, thus preventing paint from scattering in advance.

[0123] It should be noted that, when the bell cup 33 is not mounted on the shaft 313, the controller 21 allows paint spraying commands to be issued via the operation panel 23 even when the pneumatic motor 31 has stopped. Because the pneumatic motor 31 is stopped, the paint will not scatter. Because the bell cup 33 is not mounted on the shaft 313, the paint will not flow backwards. Based on the amount of paint sprayed from the feed pipe 34, the operator can confirm whether the coating machine 3 has sprayed the amount of paint corresponding to the paint spraying instruction.

[0124] (Eleventh aspect) In the eleventh aspect, based on the control device 100 of the robot system 1 described in the ninth or tenth aspect, when the installation check of the bell cup 33 is performed on the operation panel 23, the controller 21 detects the installation status of the bell cup 33.

[0125] In other words, the operator can also manually instruct the installation check of the bell cup 33.

[0126] (Twelfth aspect) In the twelfth aspect, based on the control device 100 of the robot system 1 described in the ninth or tenth aspect, when the robot 2 is prepared for operation on the operation panel 23, the controller 21 detects the installation status of the bell cup 33.

[0127] In other words, if the operator performs the operation preparation operation for robot 2, the controller 21 can automatically detect the installation status of the bell cup 33. This can prevent accidental operation such as the operator instructing robot 2 to perform painting actions when the bell cup 33 is not installed.

[0128] (Thirteenth aspect) The thirteenth aspect relates to a control method for a robot system 1, wherein an electro-proportional valve 41 activates a pneumatic motor 31 by supplying air to a pneumatic motor 31 of a rotary atomizing coating machine 3 supported by a robot 2, and a controller 21 detects whether a bell cup 33 is mounted on the pneumatic motor 31 based on specific parameters related to the operation of the pneumatic motor 31 when it is activated. If the bell cup 33 is not mounted on the pneumatic motor 31, the controller 21 enables paint spraying commands issued via the operation panel 23 when the pneumatic motor 31 is stopped; if the bell cup 33 is mounted on the pneumatic motor 31, the controller 21 invalidates paint spraying commands issued via the operation panel 23 when the pneumatic motor 31 is stopped.

[0129] With the bell cup 33 removed from the pneumatic motor 31 and the pneumatic motor 31 stopped, the operator issues a paint spraying command. Since the paint is sprayed from the feed pipe 34, the operator can confirm that the paint machine 3 has sprayed the amount of paint corresponding to the paint spraying command.

[0130] With the bell cup 33 mounted on the pneumatic motor 31 and the pneumatic motor 31 stopped, paint will not be sprayed out of the feed pipe 34 even if the operator issues a command to spray paint. This can prevent paint backflow in advance.

[0131] (Fourteenth aspect) In the fourteenth aspect, based on the control method of the robot system 1 described in the thirteenth aspect, when the bell cup 33 is not mounted on the pneumatic motor 31, the controller 21 invalidates the painting action command of the robot 2 issued via the operation panel 23.

[0132] If the bell-shaped cup 33 is not mounted on the shaft 313, the coating machine 3 cannot coat the workpiece 9. The controller 21 has an interlock function, thus preventing paint splattering in advance.

Claims

1. A monitoring device for a coating machine, characterized in that: The monitoring device for the coating machine includes a rotary atomizing coating machine, an electric proportional valve, and a controller. The rotary atomizing coating machine coats workpieces by simultaneously rotating a bell-shaped cup (detachably mounted on the top of the pneumatic motor's shaft) using a pneumatic motor, and supplying paint to the bell-shaped cup via a feed pipe. The electro-proportional valve supplies air to the pneumatic motor. The controller outputs a start command to the electro-proportional valve to start the pneumatic motor, and detects whether the bell cup is mounted on the shaft based on specific parameters related to the operation of the pneumatic motor at start-up.

2. The monitoring device for the coating machine according to claim 1, characterized in that: The monitoring device for the coating machine includes a sensor that measures the rotational speed of the pneumatic motor. The electro-proportional valve adjusts the air supply to the pneumatic motor based on the rotational speed of the pneumatic motor measured by the sensor, so that the rotational speed of the pneumatic motor becomes the target rotational speed. The controller detects whether the bell cup has been installed on the shaft based on the rotational speed of the pneumatic motor measured by the sensor.

3. The monitoring device for the coating machine according to claim 2, characterized in that: When the pneumatic motor starts, the controller detects whether the bell-shaped cup has been installed on the shaft based on the time it takes for the pneumatic motor to reach the target speed.

4. The monitoring device for the coating machine according to claim 2, characterized in that: When the pneumatic motor starts, the controller detects whether the bell cup has been installed on the shaft based on the overshoot amount by which the rotational speed of the pneumatic motor exceeds the target rotational speed.

5. The monitoring device for the coating machine according to claim 2, characterized in that: The controller performs feedback control of the pneumatic motor's speed based on the speed measured by the sensor. The controller detects that the bell cup has been installed on the shaft based on the fact that the rotational speed of the pneumatic motor is stable at the target rotational speed.

6. The monitoring device for a coating machine according to claim 5, characterized in that: The controller detects whether the bell cup has been installed on the shaft based on the integral of the absolute value of the difference between the rotational speed of the pneumatic motor when it starts and the target rotational speed.

7. The monitoring device for a coating machine according to claim 2, characterized in that: The electro-proportional valve supplies air to the pneumatic motor at a specified constant pressure when the pneumatic motor starts. The controller detects whether the bell cup has been installed on the shaft based on the rotational speed of the pneumatic motor after a specified time since the pneumatic motor was started.

8. The monitoring device for a coating machine according to any one of claims 1 to 7, characterized in that: The painting machine is supported by the robot's arm.

9. A control device for a robot system, characterized in that: The control device of the robot system includes a robot, a rotary atomizing coating machine, an electric proportional valve, a controller, and an operation panel. The rotary atomizing coating machine is supported by the robot's arm and coats workpieces by feeding paint into a bell-shaped cup (detachably mounted on the shaft of a pneumatic motor) via a feed pipe while the bell-shaped cup rotates using a pneumatic motor. The electro-proportional valve supplies air to the pneumatic motor. The controller outputs a start command to the electro-proportional valve to activate the pneumatic motor, and detects whether the bell cup is mounted on the shaft based on specific parameters related to the pneumatic motor's operation during startup. The control panel outputs the operation commands for the robot and the painting machine, corresponding to the operator's commands, to the controller. With the bell cup already mounted on the shaft, the controller invalidates paint spraying commands issued via the control panel when the pneumatic motor has stopped.

10. The control device for the robot system according to claim 9, characterized in that: If the bell cup is not mounted on the shaft, the controller invalidates the painting action commands issued by the robot via the control panel.

11. The control device for the robot system according to claim 9 or 10, characterized in that: When the installation check of the bell-shaped cup is performed on the control panel, the controller detects the installation status of the bell-shaped cup.

12. The control device for the robot system according to claim 9 or 10, characterized in that: When the robot's operation preparation operation is performed on the control panel, the controller detects the installation status of the bell-shaped cup.

13. A control method for a robot system, characterized in that: The electro-proportional valve activates the pneumatic motor by supplying air to it in a rotary atomizing paint machine supported by a robot. The controller detects whether the bell cup has been installed on the pneumatic motor based on specific parameters related to the operation of the pneumatic motor when it is started. When the bell-shaped cup is not mounted on the pneumatic motor, the controller enables paint spraying operations performed via the control panel while the pneumatic motor is stopped. With the bell cup already mounted on the pneumatic motor, the controller disables paint spraying operations performed via the control panel when the pneumatic motor is stopped.

14. The control method for the robot system according to claim 13, characterized in that: If the bell-shaped cup is not mounted on the pneumatic motor, the controller invalidates the painting action commands issued by the robot via the control panel.

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