Material box conveying system and material box carrying system

Abstract

The invention discloses a material box conveying system and a material box carrying system.The material box conveying system comprises a plurality of conveyors and a control system connected with the conveyors, and when it is determined that a material box is placed on a conveyor used for being in butt joint with a carrying crown block and a conveying line of the material box is determined, the conveying line of the material box is determined; the control system controls the multiple conveyors on the conveying line to convey the material boxes to the end point, and in the material box conveying process, the control system controls the linear speeds of the adjacent conveyors to be kept synchronous through a multi-axis cooperative control algorithm. According to the method, in the material box conveying process, the conveying speeds of the adjacent conveyors are kept synchronous through the multi-axis cooperative control algorithm, so that the shaking situation caused by the speed difference when the material boxes are connected between the adjacent conveyors can be reduced to the maximum extent, and the stability and safety of long-distance conveying are effectively guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of material box handling equipment, in particular to a material box transmission system and a material box handling system. Background Art

[0002] FOUP and other cassettes are used to hold wafers.

[0003] In an automated factory, the material boxes need to be transferred between the overhead crane (OHT) system and the stocker through a material box transfer system.

[0004] As shown in the patent document with application publication number CN119764222A, the transmission system uses multiple conveyors in a specific layout to realize the transmission of the material box.

[0005] The problems with this transmission system are: Each material box will pass through multiple conveyors when being transported on the transmission line, and the conveying speeds of adjacent conveyors often differ due to various reasons. This causes the material box to shake and deviate significantly due to the speed difference when entering from one conveyor to the next. Especially when the transmission line is relatively long, this problem will be further amplified, increasing the risk of wafer damage. Summary of the Invention

[0006] The purpose of the present invention is to solve the above problems existing in the prior art and to provide a material box transmission system and a material box handling system.

[0007] The purpose of the present invention is achieved through the following technical solutions: The material box transmission system includes multiple conveyors and a control system connected to the conveyors. When it is determined that a material box is placed on a conveyor for docking with a transport crane and the transmission route of the material box has been determined, the control system controls the multiple conveyors on the transmission route to transmit the material box to the end point. During the material box transmission process, the control system controls the linear speed of adjacent conveyors to maintain synchronization through a multi-axis collaborative control algorithm.

[0008] Preferably, when determining that the material box is placed on the conveyor for docking with the overhead crane, the control system plans a transmission route for the material box.

[0009] Preferably, the control system includes a transport controller, which communicates with a plurality of drivers via a branch, each driver controlling a transport motor of at least one conveyor, and the driver has a built-in motion control algorithm for motion control.

[0010] Preferably, the transport controller uses the virtual axis mapped from each transport motor to control the corresponding transport motor.

[0011] Preferably, the transport controller communicates with sensors on the transporter via distributed I / O modules.

[0012] Preferably, when the control system controls the transport of several consecutive conveyors on a transmission line, one conveyor is used as the master conveyor and the other conveyors are used as slave conveyors. The multi-axis coordinated control algorithm uses the following formula to determine the linear speed to be adjusted for each slave conveyor each time: V 从 =V 主 +Kp*(S 主 −S 从 ); Among them, V 从 V is the linear speed to be adjusted from the conveyor at one time; 主 is the linear speed of the main feed line; Kp is the proportional gain coefficient; S 主 S is the cumulative displacement of the main conveyor during a predetermined period of time determined based on the output signal of the encoder of the main conveyor since the start of a slave conveyor; 从 It is the cumulative displacement of the slave conveyor during a predetermined period of time after it is started, determined based on the output signal of the encoder of the slave conveyor.

[0013] The material box transmission system includes multiple conveyors and a control system connected to the conveyors. When a material box is determined to be placed on a conveyor for docking with a material storage warehouse and the transmission route of the material box has been determined, the control system controls the multiple conveyors on the transmission route to transmit the material box to the end point. During the material box transmission process, the control system controls the linear speed of adjacent conveyors to maintain synchronization through a multi-axis collaborative control algorithm.

[0014] Preferably, when the material box is transported to a conveyor for docking with a transport crane or a conveyor for docking with a material storage warehouse, the control system determines whether there is a deviation between the actual position of the material box on the conveyor and the target position based on the distance measuring sensor. When it is determined that there is a deviation, the control system controls the conveyor to start again to compensate for the deviation.

[0015] The present invention also discloses a material box transport system, comprising any of the material box transmission systems described above, and also comprising a material storage depot.

[0016] Preferably, the storage bracket of the storage depot is taught in position by a position teaching device including a camera in cooperation with a laser sensor.

[0017] The advantages of the technical solution of the present invention are mainly reflected in: During the material box transmission process, the method of the present invention synchronizes the conveying speeds of adjacent conveyors through a multi-axis collaborative control algorithm, thereby minimizing the jitter caused by the speed difference when the material box is handed over between adjacent conveyors, effectively ensuring the stability and safety of long-distance transportation.

[0018] The PLC of the entire control system of the present invention adopts a non-axis-occupying control mode, which breaks through the problem that the traditional axis-occupying control mode is limited by the number of PLC motion control modules. It can greatly improve the scalability and flexibility of the control system and meet the task requirements of complex multi-axis collaborative handling in semiconductor manufacturing.

[0019] The present invention provides a distance measuring sensor at the conveyor used to dock with the transport crane and the storage warehouse, which can effectively determine whether the position of the material box on the docking conveyor is accurate, and perform position compensation when it is inaccurate, which can effectively ensure accurate docking with the transport crane and the storage warehouse, thereby improving the safety of transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a top view of an embodiment of a cartridge transport system of the present invention; Figure 2 It is a framework diagram of the control system of the present invention; Figure 3 It is a schematic diagram of the layout of sensors on a conveyor for docking with a transport crane and a material storage warehouse according to the present invention; Figure 4 It is a partial schematic diagram of the material box handling system of the present invention; Figure 5 It is a schematic diagram of the position relationship between the position teaching device of the present invention and the storage bracket when performing position teaching; Figure 6 This is a schematic diagram of the connection between the industrial computer, storage PLC, 2D camera and laser sensor in the storage warehouse of the present invention; Figure 7 It is a partial top view schematic diagram of the storage warehouse of the present invention; Figure 8 It is a top view of the 2D camera of the present invention performing photo acquisition on the storage bracket. DETAILED DESCRIPTION

[0021] The objects, advantages, and features of the present invention are illustrated and explained through the following non-limiting description of preferred embodiments. These embodiments are merely typical examples of the application of the technical solutions of the present invention, and any technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed by the present invention.

[0022] In the description of the scheme, it should be noted that the terms "center," "upper," "lower," "left," "right," "front," "back," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplification. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] Example 1 The material box transmission system disclosed by the present invention is described below with reference to the accompanying drawings. Figure 1 As shown, it includes multiple conveyors 4 and a control system connected to the conveyors 4. The specific structure of the conveyors 4 is the same as the transmission equipment disclosed in the patent literature cited in the background technology, and will not be described in detail here. The number and specific location of the conveyors 4 can be designed as needed and are not limited here.

[0024] Like the existing material box transmission system, in a group of the conveyors 4, at least one is used to dock with the transport crane, and at least one is used to dock with the storage, that is, dock with the storage's in / out robot. Preferably, there are multiple conveyors 4 used to dock with the transport crane and the storage.

[0025] As attached Figure 2 As shown, the control system includes a transport controller and multiple drivers 2 communicating therewith. Each driver 2 is used to control the conveyor motor of a conveyor 4. The transport controller is preferably a PLC 1. The PLC 1 and the multiple drivers 2 utilize a master-slave communication architecture, with the PLC 1 serving as the master and the drivers 2 serving as slaves. High-speed data exchange between the master and slaves occurs via real-time industrial Ethernet (e.g., EtherCAT or Profinet). Preferably, the PLC 1 communicates with the multiple drivers 2 via at least one EtherCAT splitter 3. The EtherCAT splitter 3 can also be connected to another EtherCAT splitter 3, which in turn connects multiple drivers 2.

[0026] At the same time, each EtherCAT branch 3 can also be connected to the sensors of each conveyor 4 through the distributed I / O module 5, as shown in the attached Figure 3As shown, the sensors include but are not limited to an in-position sensor 401, a docking communication sensor 402, a first position sensor 403, and a second position sensor 404. The in-position sensor 401, the first position sensor 403, and the second position sensor 404 may be proximity sensors. The first position sensor 403 and the second position sensor 404 may also be a through-beam sensor or a self-reflective sensor in combination with a reflector. The docking communication sensor 402 is, for example, an E84 photoelectric communication sensor. Furthermore, the in-position sensor 401 and the docking communication sensor 402 may be installed only on the conveyor that needs to dock with the overhead crane and the material storage.

[0027] At the same time, during transmission control, the PLC1 is responsible for logic control and path planning. The logic control is, for example, the start and stop control and direction control of each conveyor 4. The path planning is to determine the transmission route of the material box from the starting point to the end point. When the starting point is the conveyor 4 docked with the transport crane, the end point is the conveyor 4 used to dock with the material storage warehouse. When the starting point is the conveyor 4 used to dock with the material storage warehouse, the end point is the conveyor 4 docked with the transport crane.

[0028] The driver 2 is an intelligent driver with built-in motion control algorithms (for example, PID regulation, speed loop control, position loop control, etc.). It only needs to receive high-level instructions from PLC1 (such as start, stop, target position, target speed, speed curve, etc.) to independently control the conveying motor of the conveyor to which it is connected, thereby breaking the barrier of traditional control methods being limited by PLC1 axis resources.

[0029] At the same time, each conveying motor is converted into a virtual axis at the software level through mapping and managed through a unified interface. PLC1 can control the corresponding conveying motor by calling each virtual axis. This is a known technology and will not be described in detail here.

[0030] When the transmission system is working, after the transport crane carries the material box and moves to the vicinity of the material box transmission system, it sends a docking request to the PLC1 via wireless means, and the docking request includes information such as the position and status of the material box.

[0031] PLC1 determines the conveyor 4 to be docked with the transport crane and notifies the transport crane. After the transport crane moves to the conveyor 4 to be docked and completes interactive docking with the conveyor 4 to be docked, the material box is placed on the conveyor 4 to be docked. Furthermore, after the conveyor 4 to be docked with the transport crane is determined, a transmission route for the material box can be immediately planned. Of course, transmission route planning can also be performed at other appropriate times, such as when the material box is placed on the conveyor 4 to be docked with the transport crane. Preferably, transmission route planning can be performed immediately after the material box is placed on the conveyor 4 to be docked with the transport crane.

[0032] When it is determined that a material box is placed on a conveyor 4 for docking with a transport crane and the transmission route of the material box has been determined, the control system controls multiple conveyors 4 on the transmission route to transmit the material box to the end point. During the material box transmission process, the control system controls the linear speed of adjacent conveyors 4 to maintain synchronization through a multi-axis collaborative control algorithm.

[0033] In detail, the PLC1 can divide the transmission process of the material box into multiple transmission stages according to whether the conveyor 4 passing through the transmission line needs to turn. For example, when a conveyor 4 on the transmission line needs to turn once, the entire transmission process can be divided into two transmission stages for control. The conveyor that needs to turn is the starting point of the first transmission stage and the end point of the second transmission stage.

[0034] Correspondingly, when the control system controls the conveying of several consecutive conveyors 4 corresponding to a transmission stage on the transmission line, one conveyor 4 is used as the master conveyor and the other conveyors 4 are used as slave conveyors. The multi-axis coordinated control algorithm uses the following formula to determine the linear speed to be adjusted for each slave conveyor each time: The multi-axis coordinated control algorithm uses the following formula to determine the linear speed to which each slave conveyor is adjusted each time: V 从 =V 主 +Kp*(S 主 −S 从 ); Among them, V 从 V is the linear speed to be adjusted from the conveyor at one time; 主 is the linear speed of the main feed line; Kp is the proportional gain coefficient; S 主 S is the cumulative displacement of the main conveyor during a predetermined period of time determined based on the output signal of the encoder of the main conveyor since the start of a slave conveyor; 从 It is the cumulative displacement of the slave conveyor during a predetermined period of time after it is started, determined based on the output signal of the encoder of the slave conveyor.

[0035] For example, when a transmission line needs to pass through 6 conveyors and needs to turn at the third conveyor, the entire transmission process can be divided into 2 transmission stages. For the convenience of explanation, the 6 conveyors are described in order from upstream to downstream as the first conveyor, the second conveyor, the third conveyor...the sixth conveyor. Therefore, the first transmission stage is from the first conveyor to the third conveyor, and the second transmission stage is from the third conveyor to the first conveyor.

[0036] In the first transmission stage, the control system controls the three conveyors 4 to start conveying in sequence. The time difference between the sequential starts can be set as needed and is not limited here. At this time, the PLC1 can determine that the first conveyor is the master conveyor and the second and third conveyors are slave conveyors. The PLC1 sends control signals to the drivers 2 of the three conveyors 4 in the order of the first conveyor, the second conveyor, and the third conveyor to start and run them at a linear speed of 1 mm / s. The PLC1 also informs the driver 2 of the first conveyor that the first conveyor is the master conveyor and informs the drivers 2 of the second and third conveyors that the second and third conveyors are slave conveyors.

[0037] After receiving the start signal, the driver 2 of the first conveyor drives the first conveyor to start and run at a linear speed of 1 mm / s, and the driver 2 of the first conveyor broadcasts the encoder data of the first conveyor it has collected to the drivers 2 of the second conveyor and the third conveyor. The drivers 2 of the second conveyor and the third conveyor dynamically adjust the linear speeds of the second conveyor and the third conveyor according to the above formula, thereby achieving linear speed synchronization of the first, second and third conveyors.

[0038] The following description will take the synchronous control process of the driver 2 of the second conveyor as an example.

[0039] When the driver 2 of the second conveyor drives the second conveyor to start and run for 1 second at a set linear speed of 1 mm / s, it is assumed that the displacement S of the first conveyor during the 1 second period after the second conveyor starts is determined based on the output signal of the encoder connected to the conveying motor of the first conveyor. 主 = 100 mm, and the displacement S of the second conveyor during 1 second after starting is determined based on the output signal of the encoder connected to the conveying motor of the second conveyor. 从 =99.5 mm (0.5 mm hysteresis), and assuming Kp=0.5.

[0040] At this time, the driver 2 of the second conveyor determines the linear speed to which the second conveyor is to be adjusted as follows: V 从 =1+0.5*(100−99.5)=1.25 mm / s; That is, the second conveyor needs to increase its speed by 0.25 mm / s to catch up with the linear speed of the first conveyor.

[0041] When the second conveyor is adjusted to a speed of 1.25 mm / s and continues to run for 0.1 seconds, the driver 2 of the second conveyor determines the displacement increment ΔS of the second conveyor according to the output signal of the encoder connected to the conveyor motor of the second conveyor. 从 If it is 10.025 mm, then the cumulative displacement S of the second conveyor during the 1.1-second running period since startup is 从 = 99.5 + 10.025 = 109.525 mm. At the same time, the driver 2 of the second conveyor determines the cumulative displacement S of the first conveyor during the 1.1-second period from the startup of the second conveyor according to the output signal of the encoder of the first conveyor. 主 = 110 mm.

[0042] Then at this time, the linear speed that the driver 2 of the second conveyor determines for the second conveyor to be adjusted to is as follows: V 从 = 1 + 0.5 * (110 - 109.525) = 1.2375 mm / s; After re-adjusting the speed, the detection and adjustment are still carried out at a cycle of 0.1 seconds, and the above process is repeated, so as to achieve the purpose of synchronizing the linear speed of the second conveyor with that of the first conveyor, that is, the linear speeds of the first conveyor and the second conveyor are the same or the difference in linear speeds meets the requirements. Of course, in actual control, the time for the first speed adjustment is not limited to 1 second, for example, it can be 0.5 seconds, etc., which is not limited here; and the time period for subsequent speed regulation is not limited to the above 0.1 second, for example, it can be 0.2 seconds, etc., which is not limited here.

[0043] The control process for the controller of the third conveyor to synchronize the speed of the third conveyor with that of the first conveyor is the same as above, which will not be elaborated here.

[0044] When the cartridge is transferred to the third conveyor, the third conveyor needs to stop conveying, turn, and then restart to convey again. Therefore, in the second transfer stage, the third conveyor can be used as the main conveyor, and the fourth - sixth conveyors can be used as slave conveyors. The specific principle of speed synchronization is the same as above, which will not be elaborated here.

[0045] Furthermore, if all conveyors in the transport route corresponding to a cassette do not require a turn, but the transport route involves a large number of conveyors 4, for example, six conveyors 4, the control system can also control the entire transport process in stages to avoid premature activation of subsequent conveyors, which would result in increased energy consumption. For example, the transport process for the first three conveyors 4 (the first, second, and third conveyors 4) is the first transport stage, while the transport process for the last three conveyors 4 (the fourth, second, and sixth conveyors 4) is the second transport stage. In this case, the linear speed synchronization process for the three conveyors 4 in the first transport stage is the same as described above and will not be further described here. However, PLC1 can control the fourth, second, and sixth conveyors 4 in the second transport stage to start sequentially when the cassette begins to be transported to the third conveyor. The fourth, second, and sixth conveyors can be designated as slave conveyors, with the third conveyor serving as the master conveyor, thereby synchronizing the linear speeds of the fourth, second, and sixth conveyors with the third conveyor. Of course, this is not required.

[0046] Of course, similarly, when it is determined that a material box is placed on a conveyor 4 for docking with a material storage warehouse and the transmission route of the material box has been determined, the control system controls multiple conveyors 4 on the transmission route to transmit the material box to the end point. During the transmission of the material box, the control system controls the linear speeds of adjacent conveyors 4 to maintain synchronization through a multi-axis collaborative control algorithm. The specific synchronization principle is the same as above and will not be repeated here.

[0047] Furthermore, in order to facilitate accurate docking with the transport crane and the in-and-out robots of the storage warehouse, distance sensors 405 are respectively provided on the conveyor 4 for docking with the transport crane and the conveyor 4 for docking with the storage warehouse. The distance sensors 405 are, for example, laser sensors. In addition, the distance sensor 405 provided on the conveyor 4 for docking with the transport crane is located at the end of the conveyor 4 for docking with the transport crane that is not docked with other conveyors 4 to avoid interfering with the output of material boxes from the conveyor 4 for docking with the transport crane or the input of material boxes from the outside to the conveyor 4 for docking with the transport crane. Correspondingly, the distance sensor 405 provided on the conveyor 4 for docking with the storage warehouse is located at the end of the conveyor 4 for docking with the storage warehouse that is docked with the storage warehouse to avoid interfering with the output of material boxes from the conveyor 4 for docking with the storage warehouse or the input of material boxes from the outside to the conveyor 4 for docking with the storage warehouse.

[0048] Therefore, when the material box is transported by the conveyor 4 to the conveyor 4 for docking with the transport crane, the PLC1 determines whether there is a deviation between the actual position of the material box on the conveyor 4 for docking with the transport crane and the target position based on the distance measuring sensor 405 on the conveyor 4 for docking with the transport crane. When it is determined that there is a deviation, the PLC1 controls the conveyor 4 for docking with the transport crane to start compensating for the deviation.

[0049] Similarly, when the material box is conveyed by the conveyor 4 to the conveyor 4 for docking with the material storage, the PLC1 determines whether there is a deviation between the actual position of the material box on the conveyor 4 docking with the material storage and the target position based on the distance measuring sensor 405 on the conveyor 4 for docking with the material storage. When it is determined that there is a deviation, the PLC1 controls the conveyor 4 for docking with the material storage to start again to compensate for the deviation.

[0050] Example 2 The present invention also discloses a material box transport system, as shown in the attached Figure 4 As shown, it includes any of the above-described material box transmission systems 500, and also includes a material storage warehouse 200, wherein the material storage warehouse 200 includes multiple rows of multi-layer storage racks, and each storage rack is used to store a material box.

[0051] As attached Figure 5 As shown, the storage bracket of the storage depot 200 is taught the position of the storage bracket through a position teaching device including a camera and a laser sensor. The position teaching device 100 includes a mounting frame 110. The shape of the mounting frame 110 can be designed as needed, for example, it is a frame that is approximately C-shaped. A 2D camera 121, a lens 122 and a light source 123 for collecting images are provided on the top plate of the mounting frame 110. The 2D camera 121 collects images downward and its optical axis extends in the vertical direction. The light source 123 is a ring light source 123 and is connected to the periphery of the lens 122. A connecting component for connecting the pick-and-place arm 211 at the end of the in / out robot 210 of the storage depot 200 is provided on the bottom plate 111 of the mounting frame 110. The connecting component can realize the connection between the mounting frame and the pick-and-place arm by screwing.

[0052] As attached Figure 6 As shown, the 2D camera 121 is connected to the industrial computer 220, and the industrial computer communicates with the storage warehouse PLC230. The 2D camera 121 is connected to the industrial computer 220 via a wireless network. The industrial computer 220 uses the QT platform and is connected to the OPENCV algorithm library for image processing.

[0053] As attached Figure 7 As shown, the storage warehouse PLC230 is connected to multiple servo drive units that realize the X-axis, Y-axis, Z-axis and T-axis movements of the outgoing / incoming robot 210, wherein the X-axis direction is defined as the arrangement direction of a row of storage brackets 240 in the storage warehouse 200, the Y-axis direction is perpendicular to the X-axis direction, the Z-axis direction is the vertical direction, and the T-axis is the vertical axis around which the picking and placing arm of the outgoing / incoming robot 210 rotates horizontally.

[0054] As attached Figure 5 , Attachment Figure 6 As shown, the storage PLC230 is also connected to the laser sensor 300, and the laser sensor 300 is arranged above the pick-and-place arm 211 and close to the inner end of the pick-and-place arm. Correspondingly, in the two fork arms of each of the storage brackets 240, at least one end plate outer surface facing the outgoing / incoming robot 210 is also provided with a reflective sheet 400 corresponding to the laser sensor 300. The material and size of the reflective sheet 400 can be designed as needed, such as a 10×10mm reflective sticker, reflective plate, reflector, etc.

[0055] By cooperating with the above-mentioned position teaching device and laser sensor, the position of each storage bracket can be accurately taught at a relatively low cost and difficulty, thereby ensuring the safety of entering and leaving the warehouse.

[0056] Before position teaching, the position teaching device 100 is fixed to the designated position of the pick-and-place arm 211. The specific setting can be made as needed and is not limited here. In order to facilitate the quick disassembly and assembly of the position teaching device 100 and the pick-and-place arm 211, as shown in the attached Figure 5 As shown, the connection assembly includes at least three polygonally distributed leveling legs 130 disposed on the base plate 111 and at least one quick-lock assembly 140. The quick-lock assembly 140 utilizes a known quick clamp 141 to lock the position teaching device 100 to the pick-and-place arm 211. During installation, the leveling legs 130 are placed against the top of the base plate 111. The clamping head of the quick clamp 141 on the quick-lock assembly 140 is then pressed against the bottom of the pick-and-place arm 211, thereby connecting the position teaching device 100 to the pick-and-place arm 211. When disassembly is required, the clamping head of the quick clamp is simply released to separate the position teaching device 100 from the pick-and-place arm 211. Furthermore, the leveling bolts of the leveling legs 130 can be used to level the mounting frame 110, thereby ensuring the camera is level. The specific structures of the leveling legs 130 and the quick clamp are known in the art and will not be described in detail here.

[0057] After the position teaching pendant 100 is fixed on the pick-and-place arm 211 , the conversion relationship between the camera coordinate system and the robot coordinate system is established using a known 9-point calibration method, and the actual physical size corresponding to each pixel point is calculated.

[0058] Then, a standard storage rack in the storage warehouse 200 can be calibrated by manually operating the in / out robot 210 to obtain a standard image of the standard storage rack. In the specific operation, the X-axis coordinate X of the position to which the pick-up and place arm 211 is to be moved when the standard image is taken can be determined in advance. 标 , Y-axis coordinate Y 标 and T axis coordinate T 标 , the pick-and-place arm 211 moves to the X-axis coordinate X标 , Y-axis coordinate Y 标 and T axis coordinate T 标 When the material box is in the corresponding position, the pick-and-place arm 211 is moved up and down to accurately remove the material box from the standard storage bracket or place the material box on the pick-and-place arm 211 on the standard storage bracket.

[0059] Furthermore, during calibration, when the pick-and-place arm 211 is at the X-axis coordinate X determined above, 标 , Y-axis coordinate Y 标 and T axis coordinate T 标 After the location, as attached Figure 5 , Attachment Figure 8 As shown, the pick-and-place arm 211 is located below the standard storage bracket, and the 2D camera 121 is located above the standard storage bracket. Then, the inbound / outbound robot 210 is controlled to slowly move the pick-and-place arm 211 upward until the distance between the lens 122 on the 2D camera 121 and the standard storage bracket is between 165-175 mm, preferably 170 mm. The movement is stopped and the Z-axis coordinate Z of the pick-and-place arm 211 at this time is recorded. 标 At this time, the field of view 124 of the 2D camera 121 is 220mm×200mm, so the image captured is more effective for teaching. In addition, the light spot of the laser sensor 300 is at the middle height of the reflective sheet 400. At the same time, the material box on the pick-and-place arm just falls onto the standard storage bracket. Of course, this is not necessary. At this time, the coordinates (X 标、 Y 标、 Z 标、 T 标 ), which is the standard coordinate.

[0060] After the standard coordinates are determined, since the position parameters (theoretical horizontal distance and theoretical height difference, etc.) between each storage bracket in the storage warehouse 200 are determined, the estimated position coordinates (X) to which the pick-and-place arm 211 is to move when the 2D camera 121 collects images at each other storage bracket can be estimated based on the standard coordinates and the position parameters between the other storage brackets and the standard storage bracket. 粗 ,Y 粗 ,T 粗 ,Z 粗 ) and stored in the industrial computer 220.

[0061] When a storage rack needs to be taught, the storage rack that needs to be taught can be manually selected on the manual interaction interface of the industrial computer 220 .

[0062] After the industrial computer 220 determines the manually selected storage bracket that needs to be taught, it sends a teaching task for teaching the storage bracket to the storage depot PLC 230. The teaching task at least includes the estimated position coordinates (X 粗 ,Y 粗 ,T 粗 ,Z 粗 ), and may also include information such as the number of the storage bracket that needs to be taught.

[0063] The storage PLC 230 obtains the estimated position coordinates (X 粗 ,Y 粗 ,T 粗 ,Z 粗 ), the inbound / outbound robot 210 is controlled to drive the pick-and-place arm 211 thereon to move to the first position corresponding to the estimated position coordinates and send a shooting request to the industrial computer 220.

[0064] After receiving the shooting request, the industrial computer 220 controls the 2D camera 121 on the pick-and-place arm 211 to capture the photo 1 of the storage bracket and determine whether the matching degree between the photo 1 and the standard image meets the requirements; during the specific image processing, the photo 1 is first pre-processed, including performing denoising, white balancing, color correction and other operations on the photo 1 to optimize the image quality; and the target and background are separated by binarization and Gaussian filtering.

[0065] Feature extraction and contour recognition are then performed on the preprocessed photo 1: specifically, OpenCV's findContours function is used to connect discrete edge points into a continuous contour curve. The corresponding techniques are known in the art and will not be described in detail here. The degree of match between the feature regions of photo 1 and the standard image can then be determined. When the degree of match reaches a predetermined value, it can be determined that the match between the currently acquired image and the standard image meets the requirements and that the two are successfully matched. The predetermined value can be set as needed, for example, to 99%, and is not limited here. In OpenCV, the method for determining the degree of match between two images is known in the art and is not innovative to the present invention and will not be described in detail here.

[0066] If so, that is, the degree of matching between the feature areas of Photo 1 and the standard image meets the requirements, the industrial computer 220 feeds back information that the two images (Photo 1 and the standard image) are successfully matched to the storage depot PLC230, and the industrial computer 220 stores the estimated position coordinates as the position teaching position of the storage bracket, and feeds back a message that the teaching is completed to the controller, and the storage depot PLC230 controls the pick-and-place arm to move at least along the Y-axis direction so as to retract from the top of the storage bracket to the outside of the storage bracket to avoid affecting subsequent actions.

[0067] If not, that is, the matching degree between the feature area of ​​the photo 1 and the standard image does not meet the requirements, the matching between the two fails, and the industrial computer 220 determines the angular deviation between the feature area of ​​the photo 1 and the standard image, and obtains the angular deviation compensation value T by inverting the angular deviation. 补 In OpenCV, the specific method for determining the angular deviation of the feature areas of two images is a known technology. For example, the deviation value from the center of mass of the feature areas of the two images to the image center can be determined, and the angular deviation can be obtained by determining the directional angle between the deviation values ​​of the two images. The corresponding method is not an innovation of the present invention and will not be described in detail here.

[0068] The industrial computer 220 calculates the angle deviation compensation value T 补 Feedback is given to the storage PLC 230.

[0069] The storage PLC 230 controls the in / out robot 210 to drive the pick-and-place arm 211 to move to the second position to compensate for the angle deviation. The coordinates of the second position are (X 粗 ,Y 粗 ,T 粗 +T 补 ,Z 粗 ), even if the pick-and-place arm 211 is in the first position mentioned above, only the T-axis is adjusted.

[0070] After the above adjustments, the storage PLC 230 controls the in / out robot 210 to drive the pick-and-place arm 211 to move up and down to determine the target Z-axis coordinate to which the pick-and-place arm 211 is to move based on the signal of the laser sensor 300 on the pick-and-place arm 211 .

[0071] Specifically, the target Z-axis coordinate to which the pick-and-place arm 211 is to move is determined according to the following process: The storage warehouse PLC230 controls the in / out robot 210 to drive the pick-and-place arm 211 to move upward. When it is determined that the signal of the laser sensor 300 has changed suddenly, that is, the light spot emitted by the laser sensor 300 has just moved above the reflective sheet 400, the first height coordinate Z1 of the pick-and-place arm 211 when the signal has changed suddenly is recorded.

[0072] The storage warehouse PLC230 controls the in / out robot 210 to drive the pick-and-place arm 211 to move downward. When it is determined that the signal of the laser sensor 300 has a sudden change, that is, the light spot emitted by the laser sensor 300 has just moved below the reflective sheet 400, the second height coordinate Z2 of the pick-and-place arm 211 when the signal suddenly changes is recorded.

[0073] The order in which the storage warehouse PLC230 controls the upward and downward movement of the pick-and-place arm 211 can be determined as needed and is not limited here.

[0074] The pick-and-place arm 211 is to move to the target Z-axis coordinate Z 目 =(Z1+Z2) / 2.

[0075] The storage PLC 230 controls the in / out robot 210 to drive the pick-and-place arm 211 to move to the third position along the Z axis according to the target Z axis coordinate to be moved to and sends a shooting request to the industrial computer 220. The coordinates of the third position are (X 粗 ,Y 粗 ,T 粗 +T 补 ,Z 目 ), that is, in this step, based on the above-mentioned second position, the pick-and-place arm 211 is adjusted only in the Z-axis direction.

[0076] The industrial computer 220 controls the 2D camera 121 to capture the second photo of the storage bracket and determines whether the matching degree between the second photo and the standard image meets the requirements.

[0077] If so, that is, it is determined that photo 2 matches the standard image successfully, the industrial computer 220 stores the coordinates of the third position as the position teaching position of the storage bracket, and feeds back a message of teaching completion to the storage depot PLC230. The storage depot PLC230 controls the picking and placing arm to retract at least from above the storage bracket to the outside of the storage bracket to avoid affecting subsequent actions, thereby completing the position teaching of the storage bracket.

[0078] If not, that is, it is determined that the second photo and the standard image are not matched successfully, the industrial computer 220 determines the X-axis deviation compensation value X between the feature area of ​​the second photo and the standard image. 补 and Y-axis deviation compensation value Y 补 .

[0079] The X-axis deviation compensation value X between the second photo and the standard image 补 and Y-axis deviation compensation value Y 补 Determine according to the following process: Determine the deviation between the centroid coordinates of the feature area of ​​the second photo and the centroid coordinates of the feature area of ​​the standard image (X 偏 , Y 偏 ); Multiply the deviation value by the physical size S corresponding to each pixel 像 Get the actual deviation size (X 偏 *S 像 , Y 偏 *S 像 ); The actual deviation size is converted into the X-axis deviation value X through the conversion relationship 差 And Y axis deviation value Y 差, specifically according to the following conversion relationship, X 差 =X 偏 *S 像 *cosT 补 +Y 偏 *S 像 sinT 补 , Y 差 =-X 偏 *S 像 *sinT 补 +Y 偏 *S 像 2cosT 补 .

[0080] The X-axis deviation value X 差 And Y axis deviation value Y 差 The X-axis deviation compensation value X can be obtained by taking the inverse 补 and Y-axis deviation compensation value Y 补 .

[0081] The industrial computer 220 converts the X-axis deviation compensation value X 补 and Y-axis deviation compensation value Y 补 Feedback to the storage PLC230.

[0082] The storage PLC 230 controls the in / out robot 210 to drive the pick-and-place arm 211 to move to the fourth position to compensate for the X-axis deviation and the Y-axis deviation. The coordinates of the fourth position are (X 粗 +X 补 ,Y 粗 +Y 补 ,T 粗 +T 补 ,Z 目 ).

[0083] The industrial computer 220 controls the 2D camera 121 to capture the third photo of the storage bracket and determine whether the matching degree between the third photo and the standard image meets the requirements; If so, the industrial computer 220 stores the coordinates of the fourth position as the position teaching position of the storage bracket, and feeds back a message of teaching completion to the storage depot PLC230. The storage depot PLC230 controls the picking and placing arm to retract at least from above the storage bracket to the outside of the storage bracket to avoid affecting subsequent actions, thereby completing the position teaching of the storage bracket.

[0084] If not, the industrial computer 220 ends the teaching and issues an alarm or performs the teaching again.

[0085] Furthermore, in order to improve the safety of teaching and avoid the camera colliding with the material box on the storage bracket when the pick-and-place arm 211 moves toward the storage bracket that needs to be taught, before controlling the out-and-in warehouse robot 210 to drive the pick-and-place arm 211 thereon to move to the first position, the out-and-in warehouse robot 210 is first controlled to drive its pick-and-place arm 211 to move to the detection position to detect whether there is a material box on the storage bracket. If so, an alarm is issued and teaching is stopped; if not, the out-and-in warehouse robot 210 is controlled to drive the pick-and-place arm 211 thereon to move to the first position.

[0086] When determining whether there is a material box on the storage bracket, it is determined by cooperating with a reflective sensor or a reflective plate set on the pick-and-place arm 211 and the storage bracket and a self-reflective sensor. Preferably, a reflective plate 241 is set on the top of each storage bracket, and the reflective plate 241 is located on the side of the storage bracket facing away from the out / in storage robot 210. The pick-and-place arm 211 is provided with a self-reflective sensor corresponding to the reflective plate. When there is a material box on the storage bracket, the light emitted by the self-reflective sensor is blocked, so that the self-reflective sensor cannot receive the reflected light, so that it can be determined that there is a material box on the storage bracket. Otherwise, it can be determined that there is no material box on the storage bracket.

[0087] The detection position satisfies that the X-coordinate and T-coordinate of the position of the pick-and-place arm 211 are the same as the X-axis coordinate and T-axis coordinate of the above-mentioned first position, and at the detection position, the Y-axis coordinate of the pick-and-place arm 211 corresponds to the position when the pick-and-place arm 211 has not yet extended toward the storage bracket, and the Z-axis coordinate of the pick-and-place arm 211 satisfies that the self-reflection sensor corresponds to the position of the reflector.

[0088] Furthermore, in order to improve the teaching efficiency, when the matching degree between the feature area of ​​the first photo captured at the first position and the feature area of ​​the standard image does not meet the requirements, it is further determined whether the matching degree between the feature areas of the two is greater than a set threshold. If the matching degree between the feature areas of the two is greater than the set threshold, the angular deviation of the feature area is further determined to obtain the angular deviation compensation value T. 补 .

[0089] If the matching degree of the feature areas of the two is less than or equal to the threshold, the 2D camera 121 is controlled to recapture the image and perform feature area matching again; If multiple images are recaptured and the matching degree obtained from each feature area matching is less than or equal to the threshold, the teaching is stopped and an alarm is issued. The number of repeated image acquisitions can be set as needed and is not limited here.

[0090] There are many implementation methods of the present invention, and all technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A material box transmission system, comprising a plurality of conveyors and a control system connected to the conveyors, characterized in that: When it is determined that a material box is placed on a conveyor for docking with a transport crane and the transmission route of the material box has been determined, the control system controls multiple conveyors on the transmission route to transmit the material box to the end point. During the material box transmission process, the control system controls the linear speed of adjacent conveyors to maintain synchronization through a multi-axis collaborative control algorithm.

2. The material box transmission system according to claim 1, characterized in that: When determining that the material box is placed on the conveyor for docking with the overhead crane, the control system plans a transmission route for the material box.

3. The material box transmission system according to claim 1, characterized in that: The control system includes a transport controller, which communicates with a plurality of drivers through a branch. Each driver controls a transport motor of at least one conveyor, and the driver has a built-in motion control algorithm for motion control.

4. The material box transmission system according to claim 1, characterized in that: The transport controller uses the virtual axis mapped from each transport motor to control the corresponding transport motor.

5. The material box transmission system according to claim 1, characterized in that: The transport controller communicates with sensors on the transport through distributed I / O modules.

6. The material box transmission system according to claim 1, characterized in that: When the control system controls several consecutive conveyors on a transmission line, one conveyor is used as the master conveyor and the other conveyors are used as slave conveyors. The multi-axis coordinated control algorithm uses the following formula to determine the linear speed to which each slave conveyor should be adjusted each time: V 从 =V 主 +Kp*(S 主 −S 从 ); Among them, V 从 V is the linear speed to be adjusted from the conveyor at one time; 主 is the linear speed of the main feed line; Kp is the proportional gain coefficient; S 主 S is the cumulative displacement of the main conveyor during a predetermined period of time determined based on the output signal of the encoder of the main conveyor since the start of a slave conveyor; 从 It is the cumulative displacement of the slave conveyor during a predetermined period of time after it is started, determined based on the output signal of the encoder of the slave conveyor.

7. A material box transmission system, comprising a plurality of conveyors and a control system connected to the conveyors, characterized in that: When it is determined that a material box is placed on a conveyor for docking with a material storage warehouse and the transmission route of the material box has been determined, the control system controls multiple conveyors on the transmission route to transmit the material box to the end point. During the transmission of the material box, the control system controls the linear speed of adjacent conveyors to maintain synchronization through a multi-axis collaborative control algorithm.

8. The material box transmission system according to any one of claims 1 to 7, characterized in that: When the material box is transported to the conveyor for docking with the transport crane or the conveyor for docking with the material storage, the control system determines whether there is a deviation between the actual position of the material box on the conveyor and the target position based on the distance measuring sensor. When it is determined that there is a deviation, the control system controls the conveyor to start again to compensate for the deviation.

9. The material box handling system is characterized by: It comprises the material box transmission system as described in any one of claims 1-8, and also includes a material storage warehouse.

10. The material box transport system according to claim 9, characterized in that: The storage bracket of the storage depot is taught in position through a position teaching device including a camera and a laser sensor.

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