Vacuum coating chamber laser cleaning method and device based on movable robot

Abstract

The invention relates to a vacuum coating chamber laser cleaning method and device based on a movable robot. The method comprises the following steps that a structured light camera, a laser and a dust removal device are arranged at the tail end of an operation arm of the robot; establishing a first mapping relation between a vacuum chamber coordinate system and a robot base coordinate system by taking a dry crucible in a vacuum coating chamber as a calibration object; fitting the inner wall of the vacuum chamber into a plurality of cylindrical surface models with different radiuses, and planning an acquisition line of the structured light camera; controlling the structured light camera to shoot along the acquisition line, identifying a to-be-cleaned surface of the inner wall of the vacuum chamber and updating the to-be-cleaned surface to the cylindrical surface model; planning the cleaning path and pose of the laser, and keeping the unit energy of the laser reaching the to-be-cleaned surface unchanged; and enabling the robot to move along the converted cleaning path, and driving the operation arm to control the laser to carry out operation according to the converted pose. Remote automatic operation of vacuum coating chamber laser cleaning can be achieved, and the vacuum coating chamber laser cleaning device can be rapidly matched with different coating machines.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vacuum coating equipment maintenance, in particular to a laser cleaning method and device for a vacuum coating chamber based on a movable robot. BACKGROUND

[0002] After long-term operation of a vacuum coating machine, metal oxides, deposition layers and rust are easily generated on the inner wall, baffle and crucible surface of the vacuum chamber, which affects the vacuum degree and the quality of the film layer. Due to these contaminants, gas and vapor sources are generated when the machine is started later, which makes the vacuum system unable to reach the required vacuum degree, affects the strength and sealing performance of the connection of the vacuum components, and also affects the bonding of the target material and the substrate, thereby affecting the quality of the product and leading to substandard film layers of the coating. Therefore, the vacuum chamber needs to be cleaned before the equipment is started.

[0003] Generally speaking, the vacuum coating equipment should be cleaned once after completing a certain number of coating procedures. The existing method is to repeatedly scrub the inner wall of the vacuum chamber with a saturated solution of caustic soda (NaOH), the purpose of which is to make the aluminum (AL) film react with NaOH, the film layer falls off after the reaction, and hydrogen gas is released, and then the vacuum chamber is cleaned with water and the dirt in the precision extraction valve is cleaned with a cloth soaked in gasoline. This cleaning method may corrode the substrate, the waste liquid needs to be treated in an environmentally friendly manner, and it is difficult to clean complex structures or small parts. In addition, personnel entering the cavity may cause secondary pollution, and the operator needs to operate in a small space, which exists metal dust and poor engineering conditions.

[0004] Document CN221854736U discloses a coating device with laser cleaning, wherein the laser cleaning mechanism is arranged on the rack and used for cleaning the cooling roller. The laser cleaning mechanism can only clean specific areas in a set manner, has poor versatility, low automation degree, and cannot observe the working condition in real time. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a laser cleaning method and device for a vacuum coating chamber based on a movable robot, which can realize remote automatic operation of laser cleaning of the vacuum coating chamber and quickly adapt to different coating machines.

[0006] The technical solution adopted by the present application to solve the technical problem is to provide a laser cleaning method for a vacuum coating chamber based on a movable robot, comprising the following steps:

[0007] A tool system is arranged at the end of the operating arm of the robot, and the tool system comprises a structured light camera and a laser;

[0008] A vacuum chamber coordinate system is established with the rotation center of the dry crucible in the vacuum coating chamber as the origin;

[0009] select a plurality of dry pot upper surface corner points as feature points, obtain the coordinates of the feature points in the vacuum chamber coordinate system to obtain the first feature pose of the dry pot;

[0010] The robot is moved to the vicinity of the vacuum coating chamber, and the second feature pose of the dry pot in the camera coordinate system is obtained by using the structured light camera;

[0011] Based on the first feature pose and the second feature pose, a first mapping relationship between the vacuum chamber coordinate system and the robot base coordinate system is determined;

[0012] The inner wall of the vacuum chamber is fitted as a plurality of cylindrical surface models with different radii in the vacuum chamber coordinate system, and the acquisition route of the structured light camera is planned for each cylindrical surface model and converted to the robot base coordinate system based on the first mapping relationship;

[0013] The structured light camera is controlled to shoot along the converted acquisition route, and the to-be-cleaned surface of the inner wall of the vacuum chamber is identified according to the collected data and updated to the cylindrical surface model;

[0014] Based on the updated cylindrical surface model, the cleaning path and pose of the laser are planned, so that the unit energy of the laser emitted by the laser reaches the to-be-cleaned surface unchanged;

[0015] Based on the first mapping relationship, the planned cleaning path and pose are converted to the robot base coordinate system, the robot is moved along the converted cleaning path, and the operating arm is driven to control the laser to carry out work in the converted pose.

[0016] Further, the first mapping relationship between the vacuum chamber coordinate system and the robot base coordinate system is determined based on the first feature pose and the second feature pose, comprising:

[0017] A second mapping relationship between the camera coordinate system and the tool system coordinate system, and a third mapping relationship between the tool system coordinate system and the robot base coordinate system when the structured light camera shoots the dry pot are established;

[0018] Based on the second mapping relationship and the third mapping relationship, the second feature pose is converted to the robot base coordinate system;

[0019] According to the second feature pose in the robot base coordinate system and the first feature pose in the vacuum chamber coordinate system, the first mapping relationship between the vacuum chamber coordinate system and the robot base coordinate system is established.

[0020] Further, the acquisition route of the structured light camera comprises:

[0021] Each cylindrical surface model is unfolded into a rectangular unfolded graph;

[0022] According to the positional relationship of each cylindrical surface model in the three-dimensional space, the two-dimensional space distribution of the corresponding rectangular unfolded graph is drawn;

[0023] The collection line of the structured light camera is planned according to the two-dimensional spatial distribution sequence based on the rectangular development diagram.

[0024] Further, the to-be-cleaned surface of the inner wall of the vacuum chamber is identified according to the collected data and updated to the cylindrical surface model, comprising:

[0025] The to-be-cleaned surface of the inner wall of the vacuum chamber is identified based on the collected data, and a rectangular cleaning frame in the corresponding camera coordinate system is obtained;

[0026] The cleaning frame in the camera coordinate system is converted to the robot base coordinate system based on the second mapping relationship;

[0027] The cleaning frame in the robot base coordinate system is converted to the vacuum chamber coordinate system based on the first mapping relationship, and then the rectangular cleaning frame is identified on the rectangular development diagram of the corresponding cylindrical surface model.

[0028] Further, the cleaning path and pose of the laser are planned based on the updated cylindrical surface model, so that the unit energy of the laser emitted by the laser reaches the to-be-cleaned surface unchanged, comprising:

[0029] The distance between the laser and the to-be-cleaned surface is set;

[0030] When the length of the short side of the to-be-cleaned surface is less than the length of the laser light, the laser is planned to clean along the central axis of the short side of the to-be-cleaned surface once, and the distance to the to-be-cleaned surface is kept unchanged during cleaning;

[0031] When the length of the short side of the to-be-cleaned surface is greater than the length of the laser light, the laser is planned to clean along a serpentine route covering the entire to-be-cleaned surface, and the distance to the to-be-cleaned surface is kept unchanged during cleaning.

[0032] Further, before the laser cleaning path and pose are planned based on the updated cylindrical surface model, the step of respectively inflating the four sides of the rectangular cleaning frame by a set length is further included.

[0033] Further, the to-be-cleaned surface of the inner wall of the vacuum chamber is identified based on the collected data, and a rectangular cleaning frame in the corresponding camera coordinate system is obtained, comprising:

[0034] The to-be-cleaned surface of the inner wall of the vacuum chamber is selected based on the collected data frame;

[0035] After the to-be-cleaned surface selected by the frame is binarized and segmented, the outline is extracted to form a rectangular cleaning frame in the camera coordinate system.

[0036] Further, it further comprises:

[0037] The degree of pollution is determined based on the data collected by the structured light camera.

[0038] According to the pollution degree, the moving speed of the laser is adjusted, so that the laser emitted by the laser irradiates the surface to be cleaned with high pollution degree for a long time and irradiates the surface to be cleaned with low pollution degree for a short time.

[0039] Further, the second feature pose of the dry pan in the camera coordinate system is obtained by using the structured light camera to shoot the dry pan and identifying the coordinates of the feature points in the camera coordinate system.

[0040] Further, the tool system further comprises a dust removal device, and the robot opens the dust removal device while the laser is controlled to carry out the cleaning operation, so that the smoke and dust in the cleaning process are sucked into the dust removal device.

[0041] The application also provides a movable robot-based laser cleaning device for a vacuum coating chamber, comprising:

[0042] A movable robot, the end of the operating arm of which is provided with a tool system, the tool system comprising a structured light camera and a laser;

[0043] A vision calibration module, configured to establish a vacuum chamber coordinate system with the rotation center of the dry pan in the vacuum coating chamber as the origin, select a plurality of corner points on the upper surface of the dry pan as feature points, obtain the coordinates of the feature points in the vacuum chamber coordinate system to obtain the first feature pose of the dry pan, move the robot to the vicinity of the vacuum coating chamber, and use the structured light camera to obtain the second feature pose of the dry pan in the camera coordinate system, and determine the first mapping relationship between the vacuum chamber coordinate system and the robot base coordinate system based on the first feature pose and the second feature pose.

[0044] A model processing module, configured to fit the inner wall of the vacuum chamber as a plurality of cylindrical surface models with different radii in the vacuum chamber coordinate system;

[0045] A photographing path planning module, configured to plan the collection route of the structured light camera for each cylindrical surface model and convert to the robot base coordinate system based on the first mapping relationship;

[0046] A cleaning path planning module, configured to identify the surface to be cleaned of the inner wall of the vacuum chamber based on the data collected by the structured light camera along the collection route and update to the cylindrical surface model, plan the cleaning path and pose of the laser based on the updated cylindrical surface model, so that the unit energy of the laser emitted by the laser remains unchanged when reaching the surface to be cleaned, and convert the planned cleaning path and pose to the robot base coordinate system based on the first mapping relationship;

[0047] A control system, configured to control the structured light camera to shoot along the converted collection route, control the robot to move along the converted cleaning path, and drive the operating arm to control the laser to carry out the operation in the converted pose.

[0048] Further, a human-computer interface system deployed on the terminal device is further included; the visual calibration module, the model processing module, the photographing path planning module, the cleaning path planning module and the control system are deployed on the edge computer, and the vacuum chamber model, the cleaning progress and the alarm information are sent to the human-computer interface system through a wireless network.

[0049] Advantages

[0050] Compared with the prior art, the present application has the following advantages and positive effects: the present application uses a dry pot in a vacuum chamber as a calibration object, and the mapping relationship between the vacuum chamber coordinate system and the robot base coordinate system is calibrated by operating a movable robot to take a picture of the dry pot, thereby omitting a complex calibration process and quickly and simply determining the coordinate transformation between the robot and the vacuum chamber; the present application plans a corresponding route based on a cylindrical surface model of the vacuum chamber, converts the route to the robot base coordinate system, controls the robot to move along the planned route to collect data and perform laser cleaning, and realizes high-precision spatial coordinate mapping and dynamic path planning, thereby quickly adapting to different coating machines and supporting remote control; the present application keeps the unit energy of the laser emitted by the laser unchanged when the laser reaches the surface to be cleaned through laser pose planning and real-time control, thereby ensuring balanced energy distribution and improving cleaning consistency; in addition, since the unit energy is constant during laser cleaning, the laser moving speed can be adjusted according to the pollution degree, so as to adjust the laser irradiation time to ensure the cleaning effect. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 is a flowchart of the first embodiment of the present application;

[0052] Figure 2 is a structure diagram of a vacuum coating chamber in the first embodiment of the present application;

[0053] Figure 3 is a structure diagram of a movable robot in the first and second embodiments of the present application;

[0054] Figure 4 is a photographing path planning schematic diagram of the first embodiment of the present application;

[0055] Figure 5 is a cleaning path planning schematic diagram of the first embodiment of the present application;

[0056] Figure 6 is a system control architecture schematic diagram of the second embodiment of the present application. DETAILED DESCRIPTION

[0057] The application will be further described in connection with the following specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not used to limit the scope of the application. Furthermore, it should be understood that after reading the content of the application, those skilled in the art can make various modifications or changes to the application, and these equivalent forms also fall within the scope of the appended claims.

[0058] The first embodiment of the application relates to a laser cleaning method for a vacuum coating chamber based on a movable robot, as shown in the accompanying drawings, comprising the following steps: Figure 1

[0059] A tool system is deployed at the end of the operating arm of the robot, wherein the tool system comprises a structured light camera and a laser;

[0060] A vacuum chamber coordinate system is established with the rotation center of the dry pan in the vacuum coating chamber as the origin;

[0061] A plurality of corner points on the upper surface of the dry pan are selected as feature points, and the coordinates of these feature points in the vacuum chamber coordinate system are obtained to obtain the first feature pose of the dry pan;

[0062] The robot is moved to the vicinity of the vacuum coating chamber, and the second feature pose of the dry pan in the camera coordinate system is obtained by using the structured light camera;

[0063] Based on the first feature pose and the second feature pose, a first mapping relationship between the vacuum chamber coordinate system and the robot base coordinate system is determined;

[0064] The inner wall of the vacuum chamber is fitted as a plurality of cylindrical surface models with different radii in the vacuum chamber coordinate system, and the collection route of the structured light camera is planned for each cylindrical surface model and converted to the robot base coordinate system based on the first mapping relationship;

[0065] The structured light camera is controlled to take pictures along the converted collection route, and the to-be-cleaned surface of the inner wall of the vacuum chamber is identified according to the collected data and updated to the cylindrical surface model;

[0066] Based on the updated cylindrical surface model, the cleaning path and pose of the laser are planned, so that the unit energy of the laser emitted by the laser remains unchanged when it reaches the to-be-cleaned surface;

[0067] Based on the first mapping relationship, the planned cleaning path and pose are converted to the robot base coordinate system, the robot is moved along the converted cleaning path, and the operating arm is driven to control the laser to carry out work in the converted pose.

[0068] The first mapping relationship is calibrated by using the corner points on the upper surface of the dry pan in the vacuum coating chamber as feature points, and specifically includes:

[0069] ​establishing a second mapping relationship between the camera coordinate system and the tool system coordinate system, and a third mapping relationship between the tool system coordinate system and the robot base coordinate system when the structured light camera captures the dry pan;

[0070] Based on the second mapping relationship and the third mapping relationship, the second feature pose is converted to the robot base coordinate system;

[0071] According to the second feature pose in the robot base coordinate system and the first feature pose in the vacuum chamber coordinate system, a first mapping relationship between the vacuum chamber coordinate system and the robot base coordinate system is established.

[0072] Because the constructed vacuum chamber digital model is in the vacuum chamber coordinate system, the path planned based on the model is also in the vacuum chamber coordinate system, and by using the mapping relationship of each coordinate system, the planned path in the vacuum chamber coordinate system can be converted to the robot base coordinate system.

[0073] As shown in Figure 2 The upper surface of the dry pan 102 in the vacuum coating chamber 101 is distributed with a plurality of corner points 103, and four corner points at different positions are preferably used as feature points for calibration, such as two pairs of corner points symmetrically distributed relative to the center of rotation of the dry pan.

[0074] The inner wall of the vacuum coating chamber is a cylindrical surface mechanism, and the internal devices are mainly various pipelines and cylindrical shells, so it can be abstracted as a three-dimensional digital model composed of multiple cylindrical surfaces. When planning the route, the three-dimensional digital space can be converted into a two-dimensional planar distribution, which specifically includes:

[0075] Each cylindrical surface model is unfolded into a rectangular unfolded diagram;

[0076] According to the positional relationship of each cylindrical surface model in the three-dimensional space, the two-dimensional spatial distribution of the corresponding rectangular unfolded diagram is drawn;

[0077] Based on the two-dimensional spatial distribution of the rectangular unfolded diagram, the collection route of the structured light camera is planned.

[0078] The data collected by the structured light camera can be mapped to the three-dimensional digital model, so as to combine its two-dimensional planar distribution for route planning of cleaning operation. In addition, in order to keep the unit energy of the laser emitted by the laser unchanged when it reaches the surface to be cleaned, the laser pose can be adjusted so that it is equal to the distance from the surface to be cleaned, so that the energy attenuation of the emitted light in the air remains consistent, and the unit energy reaching the cleaning surface is constant.

[0079] In some preferred embodiments, the degree of pollution can be determined according to the data collected by the structured light camera, and the laser moving speed can be adjusted according to the degree of pollution, so that the laser emitted by the laser emits for a long time on the surface to be cleaned with high degree of pollution, and emits for a short time on the surface to be cleaned with low degree of pollution, so as to achieve better cleaning effect.

[0080] A preferred embodiment 1 of the present application is a movable laser cleaning system and path planning method suitable for multiple different types and positions of coating machines, involving visual recognition, equipment maintenance, laser application and automation field, including the identification of the calibration object and parameter of the vacuum chamber of the coating machine involved by using a structured light camera, the selection of cleaning area and laser intensity, cleaning process and dust removal, and remote control of human-machine collaborative robot execution.

[0081] The composition of the movable robot is shown in Figure 3 , including a moving platform 201, a laser 202, a 3D camera 203, a dust collector 204, a robot operating arm 205, and a mechanical arm base 206.

[0082] Before the cleaning operation, the space coordinate of the coating machine vacuum chamber needs to be calibrated. During work, the pose of the laser in the space of the vacuum chamber is obtained through the calibration data, the vacuum chamber is scanned according to the planned path, the area to be cleaned is identified according to the obtained point cloud data, the cleaning path is generated by planning the slices, the instructions are transmitted to the robot controller, and the vacuum chamber wall surface graph and the cleaning path are displayed on the operation interface, and the cleaning work is executed by manual or remote control. This method improves the intelligence, flexibility and automation degree of operation, improves the operation efficiency and the health and safety of the operator, and provides an efficient and intuitive solution for remote control of human-machine collaborative arms. Specifically, the following steps are included:

[0083] (a) Install the tool system composed of a structured light camera, a laser and a dust collector on the end flange of the collaborative robot, obtain the coordinate transformation matrix T 相机 , T 激光 of the camera coordinate system, the laser coordinate system and the robot tool coordinate; transform the robot tool coordinate system to the robot base coordinate system T 基 (T 基 needs to be calculated in real time according to the forward kinematics of the robot);

[0084] (b) Select a dry pan at the evaporation position as the calibration object, and establish the vacuum chamber coordinate system O 真空 with its rotation center, and establish a three-dimensional model of the vacuum chamber with this coordinate system, to obtain the digital model of the wall surface and other surfaces to be cleaned and rusted. Take the four corner points of the dry pan as the identification feature points to obtain the feature pose of the dry pan:

[0085] P 干锅-真空= (P1, P2, P3, P4);

[0086] (c) Establishing the transformation matrix between the robot base coordinate and the vacuum chamber coordinate system: moving the mobile platform to the vicinity of the coating machine, acquiring the pose of the pan in the camera coordinate system P 干锅-相机 , through the structured light camera, so as to determine the transformation matrix T 变 between the robot base coordinate and the vacuum chamber coordinate system;

[0087] (d) According to the three-dimensional model of the vacuum chamber wall surface, a cylindrical surface is used for approximate fitting to obtain the digital model in the vacuum chamber coordinate system O 真空 , so as to plan the moving path and the shooting point of the 3D camera. If the shooting point W on the planned shooting path in the coordinate system O 真空 is W 真空 , the motion of the collaborative robot needs to be controlled (in the robot base coordinate system): W 基 = T 变 W 真空 , and the camera coordinate is converted to the robot base coordinate: S 相机 = T 基 T 基 S 相机 , and the base coordinate is converted to the vacuum chamber coordinate: S 相机 = T 真空 -1 变 S 基 , and the cleaning area M 真空 and the required laser intensity are identified by using the visual recognition method;

[0088] (e) According to the optimal distance d of the laser from the cleaning surface M 真空 , the pose P 真空 of the laser is obtained, the system plans the cleaning path of the laser, and the generated task path information is transmitted to the robot controller. The path P 真空 planned in the vacuum coordinate system is converted to the robot base coordinate system: P 基 = T 变 P 真空 , the mechanical arm drives the laser to this position, and the light of the laser is controlled to be parallel to the generatrix of the cylindrical surface. In this way, the laser and the cleaned surface are at equal distances, achieving a better cleaning effect. Along the planned cleaning path, the dust removal device is opened while working, and the smoke and dust are sucked into the dust removal device;

[0089] (f) After all the cleaning is completed, manual confirmation is performed. If manual cleaning is still required, the operator can remotely operate the PAD to perform manual operation. After the completion of the whole process, the robot automatically retracts and leaves the vacuum chamber of the coating machine, and the operator moves the mobile platform to the next coating machine.​

[0090] The origin of the vacuum chamber coordinate system can be selected at the center of rotation of the dry pot to establish the vacuum chamber coordinate system O 真空 According to the vacuum chamber CAD drawing, and approximate fitting through the cylindrical surface, if the cylinder axis is parallel to the vector d=(a,b,c) and passes through the point p0=(x0,y0,z0), the distance from the point on the cylindrical surface to the axis is r, and the height is h, the mathematical equation is:

[0091]

[0092]

[0093] According to the imaging principle, the transformation formula from the camera coordinate system to the robot base coordinate system is:

[0094] P 基 =T 基 T 相机 P 相机 (1)

[0095] Since the camera and laser are installed on the same tool, the transformation of the camera and laser coordinates is a fixed transformation:

[0096] P 激光 = T 激光 相机 P 相机 (2)

[0097] Select the four corner points on the upper surface of the dry pot as the identification coordinate system O 真空 The characteristic points of these four points are in the coordinate system O 真空 is fixed, P 干锅-真空 =(P1,P2,P3,P4). Use the 3D camera on the robot to shoot the dry pot at the evaporation point, identify the coordinates of the four corner points, and obtain their coordinates in the robot base coordinate system according to formula (1):

[0098] P 干锅-基 = T 基 T 相机 P 干锅-相机 ;

[0099] Since the dry pot is in the vacuum chamber coordinate system O 真空 The median coordinate is determined as P 干锅-真空 =(P1,P2,P3,P4), so we can get:

[0100] P 干锅-真空 = T 变 P 干锅-基 ; (3)

[0101] From this, the transformation matrix T between the robot base coordinate system and the vacuum chamber coordinate system can be determined变 .

[0102] Step (d) is fitted by cylindrical surface fitting the vacuum chamber wall surface as a cylindrical surface with different radii, so that the camera shooting path can be unfolded as a rectangle to plan the wall surface, and the overlap of each picture is set to 10mm, and the n times of shooting are planned in sequence. Figure 4 As shown in the figure: the robot arm controls the camera to move along the path, take a picture at the shooting point i, and then continue to move along the path to the next shooting point.

[0103] Step (e) is to control the position and pose of the laser according to the identified cleaning area, the generatrix and the normal direction of the surface, so that the light is parallel to the generatrix, and the energy of the laser reaching the wall surface is the same, so as to realize green (energy-saving) manufacturing and achieve optimized cleaning effect.

[0104] The robot moves along the path at a speed of 30mm / s, and the pose of the laser and the distance from the cleaning surface are controlled in real time to ensure the best cleaning effect. Assuming that the area to be cleaned is a rectangle with side length a*b, the length of the laser line is c, and the initial position of the laser line is d away from the cleaning area: (it can also be first inflated, each side is inflated by a distance d, and then the trajectory is planned in the rectangular area):

[0105] (1) When the length of the laser light c is greater than the width a+2d, the midpoint of the light directly cleans once, as shown in Figure 5 (1);

[0106] (2) Walk along the edge of the line, and the edge of the light line exceeds the cleaning edge d, and cover the entire cleaning area through the line, as shown in Figure 5 (2).

[0107] The second embodiment of the application relates to a vacuum coating chamber laser device based on a movable robot, which is used to realize the method as described above. Specifically, it comprises:

[0108] A movable robot, the end of the operating arm of which is provided with a tool system, the tool system comprising a structured light camera and a laser;

[0109] A vision calibration module is used to establish a vacuum chamber coordinate system with the rotation center of the dry pan in the vacuum coating chamber as the origin, select a plurality of corner points on the upper surface of the dry pan as feature points, obtain the coordinates of the feature points in the vacuum chamber coordinate system to obtain the first feature pose of the dry pan, move the robot to the vicinity of the vacuum coating chamber, use the structured light camera to obtain the second feature pose of the dry pan in the camera coordinate system, and determine the first mapping relationship between the vacuum chamber coordinate system and the robot base coordinate system based on the first feature pose and the second feature pose.

[0110] A model processing module is used to fit the inner wall of the vacuum chamber as a plurality of cylindrical surface models with different radii in the vacuum chamber coordinate system.

[0111] a photographing path planning module configured to plan a collection route of the structured light camera for each cylindrical surface model and convert to a robot base coordinate system based on the first mapping relationship;

[0112] a cleaning path planning module configured to identify a surface to be cleaned on the inner wall of the vacuum chamber based on data collected by the structured light camera along the collection route and update to the cylindrical surface model, plan a cleaning path and a pose of the laser based on the updated cylindrical surface model, so that the unit energy of the laser emitted by the laser remains unchanged when reaching the surface to be cleaned, and convert the planned cleaning path and pose to the robot base coordinate system based on the first mapping relationship;

[0113] a control system configured to control the structured light camera to take photos along the converted collection route, control the robot to move along the converted cleaning path, and drive the operating arm to control the laser to work at the converted pose.

[0114] In some preferred embodiments, the device further comprises a human-computer interface system deployed on the terminal equipment. The visual calibration module, the model processing module, the photographing path planning module, the cleaning path planning module and the control system are deployed on the edge computer, and the vacuum chamber model, the cleaning progress and the alarm information are sent to the human-computer interface system through a wireless network.

[0115] As shown in FIG. 2, this embodiment is a preferred embodiment 1. Figure 6 As shown in FIG. 3, this embodiment is a preferred embodiment 2.

[0116] As shown in FIG. 4, this embodiment is a preferred embodiment 3. Figure 1 As shown in FIG. 5, the movable robot comprises:

[0117] a moving platform 201 configured to transport the robot from a standby position to a door of a vacuum chamber of a coating machine;

[0118] a laser 202 configured to be a pulse fiber laser with a power of 500-1000 W and a wavelength of 1064 nm, and provided with a coaxial red light indicator;

[0119] a 3D camera 203 configured to be a structured light high-definition camera with a resolution of 2448 × 2048;

[0120] a dust remover 204 configured to be a dust suction / smoke exhaust integrated head with a negative pressure of 20 kPa and a built-in HEPA+activated carbon filter;

[0121] a robot operating arm 205 configured to be a six-axis force control collaborative robot arm with a load of 10 kg and a repeat positioning accuracy of ±0.05 mm, and provided with a quick-change disc integrated at a flange at an end thereof;

[0122] a robot arm base 206 configured to fix the robot operating arm 205 on the moving platform 201;

[0123] Communication and interaction: PAD terminal APP supports multi-touch, gesture box selection, real-time video;

[0124] Control system: deployed in edge computer, including the following modules:

[0125] Model processing module: in the vacuum chamber coordinate system, a fitting model based on the cylindrical model of the vacuum chamber will be established;

[0126] Visual calibration module: obtain 3D point cloud data of the vacuum chamber dry pan through a structured light camera, identify four corner points to establish the transformation relationship between the robot base coordinate and the vacuum chamber coordinate system;

[0127] Photographing path and point planning module: according to different coating machines, their digital models are established in advance, and the photographing points and moving paths are planned;

[0128] Cleaning path planning module: based on point cloud segmentation and feature recognition, a segmented cleaning path is generated;

[0129] Control and interaction system: the edge computer generates the path and process parameters according to the cleaning path planning module, which are transmitted to the robot controller as the robot control program, and the robot is started to execute the task;

[0130] Robot controller execution: execute the control program, the mechanical arm drives the laser to move, and adjusts the laser pose and power (or turns on and off) in real time according to the cleaning path;

[0131] Human-machine interface (HMI): PAD connects to the edge computer through Wifi, and displays the vacuum chamber model, cleaning progress and alarm information on the PAD, supporting manual / automatic mode switching.

[0132] The cleaning operation is carried out according to the following steps:

[0133] Step 1: pre-model processing and photographing point path planning: according to the CAD model of the vacuum chamber of each coating machine, a fitting digital model based on the cylindrical model of the vacuum chamber is established in the vacuum chamber coordinate system, and the photographing points and paths are planned; the distance from the point on the cylindrical surface to the axis is r, and the height is h, and the mathematical equation is:

[0134]

[0135]

[0136] The model of the wall surface in different areas is established respectively, so that the generatrix and normal vector can be obtained, the generatrix vector is the axis vector, and the normal vector is perpendicular to the generatrix and points to the axis.

[0137] Step 2: Movable calibration and space mapping: Move the robot to the vicinity of the target coating machine vacuum chamber, scan the vacuum chamber pan with the structured light camera, and obtain high-precision point cloud data. Identify four points using the calibration algorithm, identify the evaporation position of the pan with the 3D camera, and obtain the coordinates of the four corner points on the upper surface of the pan in the robot coordinate system P R : The coordinates of the four points P1, P2, P3, and P4 in the coordinate system of the vacuum chamber are P K : K1, K2, K3, and K4. In this way, the position of the robot in the vacuum chamber coordinate system can be determined P K = R K P R Since the camera is fixed at the end of the robot, the transformation relationship T 变 between the robot base coordinate system and the vacuum chamber coordinate system can be determined by PK. This is equivalent to establishing the mapping relationship between the robot base coordinate system and the vacuum chamber coordinate system through the registration of the pan. The registration error is ≤0.5 mm.

[0138] Step 3: Identify the cleaning area and plan the path: The camera transmits real-time images to the PAD, and the operator selects the rust ROI on the touch screen; the system performs binaryzation + contour extraction on the ROI to form a rectangular cleaning area, the controller determines the pose of the laser based on the surface generatrix and normal information, maintains the parallelism of the laser light and the generatrix and the distance from the surface, automatically generates the cleaning path, and displays the preview on the PAD; after the operator confirms, the task is issued with one key, and the robot enters the automatic cleaning mode. According to the pollution level, change the speed to make the laser irradiation surface time different, divide into four levels, normal speed V, heavy pollution 0.5V, medium pollution 0.75V, ordinary V, and light pollution 1.2V.

[0139] Step 4: Transfer the processing program to the robot controller: The main task of the system is completed in the edge processor, which transmits the generated robot control program to the robot controller through TCP / IP or OPC UA, starts the robot to execute the program through control commands, ensures the constant distance between the laser head and the wall surface, and controls the light formed by the laser head to be parallel to the cleaning surface generatrix, ensuring uniform energy distribution.

[0140] Step 5: Multi-mode cleaning execution:

[0141] Automatic mode: the robot completes the cleaning according to the planned path;

[0142] Manual remote collaboration mode: the operator monitors and intervenes in the cleaning parameters (such as laser power and moving speed) in real time through the HMI.

[0143] Manual mode: manual control robot to move in the vacuum coordinate system, video stream browsing, laser control and other functions. According to the image transmitted by the 3D camera to the PAD, the area to be cleaned and the cleaning intensity (laser intensity) are judged manually. According to the three-dimensional coordinates recognized by the camera and the optimal distance of the laser from the cleaning surface, the red light of the laser machine is started to identify the position of the laser light, the laser is positioned at the starting position of the cleaning area, the motion range of the laser is set, and the robot controller is started to execute.

[0144] Step 6: Dust removal and quality verification: integrated negative pressure dust removal device, real-time collection of particles generated during cleaning. The cleaning effect is verified by secondary visual scanning analysis, and unqualified areas can be marked for automatic rework. After completion, a cleaning completion PDF report is automatically generated. After cleaning, the camera takes a second shot of the ROI, calculates the rust pixel ratio p; if p > 5%, it automatically re-scans; otherwise, a cleaning report (including before and after comparison chart, time consumption, energy consumption) is generated, and manual finishing is performed.

[0145] Step 7: Retract the robot for the next device cleaning: after all is completed, set a one-key back on the HMI, the robot automatically retracts the arm, exits the vacuum chamber, and then moves (or AGV chassis automatically) to the next coating machine.

Claims

1. A laser cleaning method for a vacuum coating chamber based on a mobile robot, characterized in that: The following steps are involved: deploying a tool system at the end of the robot's manipulator arm, the tool system comprising a structured light camera and a laser; The vacuum chamber coordinate system is established with the rotation center of the crucible in the vacuum coating chamber as the origin; Select multiple corner points on the upper surface of the dry pot as feature points, obtain the coordinates of these feature points in the vacuum chamber coordinate system to obtain the first feature pose of the dry pot; Move the robot to the vicinity of the vacuum coating chamber and use a structured light camera to obtain the second characteristic pose of the dry pot in the camera coordinate system; Determining a first mapping relationship between the vacuum chamber coordinate system and the robot base coordinate system based on the first characteristic pose and the second characteristic pose; Fitting the inner wall of the vacuum chamber into multiple cylindrical surface models with different radii in the vacuum chamber coordinate system, planning an acquisition route of the structured light camera for each cylindrical surface model and converting it into the robot base coordinate system based on the first mapping relationship; Control the structured light camera to shoot along the converted acquisition route, identify the surface to be cleaned on the wall of the vacuum chamber based on the acquired data, and update it on the cylindrical surface model; The cleaning path and position of the laser are planned based on the updated cylindrical surface model, so that the unit energy of the laser emitted by the laser remains unchanged when it reaches the surface to be cleaned; Based on the first mapping relationship, the planned cleaning path and posture are converted to the robot base coordinate system, the robot is moved along the converted cleaning path, and the operating arm is driven to control the laser to perform operations in the converted posture.

2. The method according to claim 1, characterized in that Determining a first mapping relationship between the vacuum chamber coordinate system and the robot base coordinate system based on the first characteristic pose and the second characteristic pose includes: Establishing a second mapping relationship between the camera coordinate system and the tool system coordinate system, and a third mapping relationship between the tool system coordinate system and the robot base coordinate system when the structured light camera photographs the dry pot; Based on the second mapping relationship and the third mapping relationship, the second feature pose is transformed into the robot base coordinate system; A first mapping relationship between the vacuum chamber coordinate system and the robot base coordinate system is established according to the second characteristic pose in the robot base coordinate system and the first characteristic pose in the vacuum chamber coordinate system.

3. The method according to claim 2, characterized in that The acquisition circuit of the planned structured light camera includes: Expand each cylindrical surface model into a rectangular expansion diagram; According to the positional relationship of each cylindrical surface model in the three-dimensional space, draw the two-dimensional spatial distribution of the corresponding rectangular expansion diagram; Sequentially plan the acquisition route of a structured light camera based on the two-dimensional spatial distribution of a rectangular expansion diagram.

4. The method according to claim 3, characterized in that The method of identifying the surface to be cleaned on the inner wall of the vacuum chamber according to the collected data and updating the surface to the cylindrical surface model includes: Based on the collected data, the surface to be cleaned on the inner wall of the vacuum chamber is identified, and a corresponding rectangular cleaning frame in the camera coordinate system is obtained; The cleaning frame in the camera coordinate system is converted to the robot base coordinate system based on the second mapping relationship; The cleaning frame in the robot base coordinate system is converted to the vacuum chamber coordinate system based on the first mapping relationship, and then the rectangular cleaning frame is marked on the rectangular unfolded view of the corresponding cylindrical surface model.

5. The method according to claim 4, characterized in that The cleaning path and position of the laser are planned based on the updated cylindrical surface model, so that the unit energy of the laser emitted by the laser remains unchanged when it reaches the surface to be cleaned, including: Set the distance between the laser and the surface to be cleaned; When the length of the short side of the surface to be cleaned is less than the length of the laser beam, the laser is planned to perform a one-time cleaning along the central axis of the short side of the surface to be cleaned, and the distance from the surface to be cleaned remains unchanged during cleaning; When the length of the short side of the surface to be cleaned is greater than the length of the laser light, the laser is planned to clean along a serpentine route covering the entire surface to be cleaned, and the distance from the surface to be cleaned remains unchanged during cleaning.

6. The method according to claim 5, characterized in that Before planning the cleaning path and posture of the laser based on the updated cylindrical surface model, the method further includes the step of expanding the four sides of the rectangular cleaning frame outward by a set length.

7. The method according to claim 4, characterized in that The method of identifying the surface to be cleaned on the inner wall of the vacuum chamber based on the collected data and obtaining the corresponding rectangular cleaning frame in the camera coordinate system includes: Selecting the surface to be cleaned on the inner wall of the vacuum chamber based on the collected data frame; The selected surface to be cleaned is binarized and segmented, and then contours are extracted to form a rectangular cleaning frame in the camera coordinate system.

8. The method according to claim 1, characterized in that Also includes: Determine the degree of contamination based on data collected by a structured light camera; The moving speed of the laser is adjusted according to the degree of pollution so that the laser it emits irradiates the surface to be cleaned with a high degree of pollution for a long time and the surface to be cleaned with a low degree of pollution for a short time.

9. A laser cleaning device for a vacuum coating chamber based on a mobile robot, characterized in that: include: A mobile robot having a tool system deployed at the end of its operating arm, the tool system including a structured light camera and a laser; The visual calibration module is used to establish a vacuum chamber coordinate system with the rotation center of the dry crucible in the vacuum coating chamber as the origin, select multiple corner points on the upper surface of the dry crucible as feature points, obtain the coordinates of these feature points in the vacuum chamber coordinate system to obtain the first feature pose of the dry crucible, move the robot to the vicinity of the vacuum coating chamber, use a structured light camera to obtain the second feature pose of the dry crucible in the camera coordinate system, and determine the first mapping relationship between the vacuum chamber coordinate system and the robot base coordinate system based on the first feature pose and the second feature pose; A model processing module, used for fitting the inner wall of the vacuum chamber into multiple cylindrical surface models with different radii in the vacuum chamber coordinate system; A photographing path planning module is used to plan the acquisition path of the structured light camera for each cylindrical surface model and convert it into the robot base coordinate system based on the first mapping relationship; a cleaning path planning module for identifying the surface to be cleaned on the inner wall of the vacuum chamber based on data collected by the structured light camera along the acquisition route and updating the data onto a cylindrical surface model; planning the cleaning path and posture of the laser based on the updated cylindrical surface model so that the unit energy of the laser light emitted by the laser remains unchanged when it reaches the surface to be cleaned; and converting the planned cleaning path and posture into the robot base coordinate system based on the first mapping relationship; The control system is used to control the structured light camera to shoot along the converted acquisition route, move the robot along the converted cleaning path, and drive the operating arm to control the laser to perform operations in the converted posture.

10. The device according to claim 9, characterized in that It also includes a human-machine interface system deployed on the terminal device; the visual calibration module, model processing module, photo path planning module, cleaning path planning module and control system are deployed on the edge computer, and the vacuum chamber model, cleaning progress and alarm information are sent to the human-machine interface system via a wireless network.

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