Intelligent manufacturing production line practical training system based on digital twinning and virtual-real cooperative control method

Abstract

The invention discloses an intelligent manufacturing production line practical training system based on digital twinning and a virtual-real cooperative control method. The system comprises a physical execution layer which comprises a stereoscopic warehouse used for workpiece storage and positioning, an annular conveying line used for workpiece circulation, a visual inspection table used for workpiece identification and a robot used for workpiece transfer; the control layer comprises a PLC main control unit and a man-machine interaction unit and is used for realizing equipment cooperative control and operation monitoring; and the digital twin layer comprises three-dimensional virtual models corresponding to the devices in the physical execution layer, realizes bidirectional data interaction with the physical execution layer through a communication protocol, and supports virtual-real cooperative control and fault simulation. According to the invention, a practical training environment is constructed in a virtuality and reality combination mode, and the cognition, programming and maintenance capabilities of students on the intelligent manufacturing system are cultivated.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of intelligent manufacturing education, and specifically relates to a modular production line practical training system integrating digital twin technology and a control method thereof, and is particularly suitable for practical teaching of industrial robots, PLCs and multi-device collaboration. BACKGROUND

[0002] In the field of intelligent manufacturing education, practical teaching is crucial for cultivating students' practical operation ability and system cognition. The traditional intelligent manufacturing practical training system has the following shortcomings:

[0003] The practical training environment is usually a single physical production line, which is difficult to simulate complex production scenarios and fault states;

[0004] The cost of equipment is high, which is difficult to meet the demand of large-scale teaching;

[0005] If the students make a mistake during the operation, it may cause damage to the physical equipment and pose a safety hazard;

[0006] There is a lack of intuitive virtual simulation means, and students have difficulty understanding the abstract production process and system principle.

[0007] With the development of digital twin technology, combining virtual simulation with physical systems has become an effective way to solve the above problems. SUMMARY

[0008] The purpose of the present application is to provide an intelligent manufacturing production line practical training system based on digital twin and a virtual-real collaborative control method, which constructs a practical training environment through virtual-real combination, and cultivates students' cognition, programming and maintenance ability of intelligent manufacturing systems.

[0009] To achieve the above purpose, the present application adopts the following technical solutions:

[0010] An intelligent manufacturing production line practical training system based on digital twin, comprising:

[0011] A physical execution layer: including a three-dimensional warehouse for workpiece storage and positioning, a ring-shaped conveying line for workpiece transfer, a visual detection table for workpiece identification, and a robot for workpiece transfer;

[0012] The three-dimensional warehouse is provided with partitioned shelves and a storage location detection sensor;

[0013] The ring-shaped conveying line is provided with an in-out warehouse station positioning unit and a visual detection station positioning unit, each unit being provided with a blocking mechanism, a jacking mechanism and a corresponding detection sensor;

[0014] The visual detection table is provided with a detection station P1 and a temporary storage station P2;

[0015] Control layer: including PLC master unit and human-computer interaction unit, used for realizing device collaborative control and operation monitoring;

[0016] Digital twin layer: including three-dimensional virtual models corresponding to each device in the physical execution layer, realizing bidirectional data interaction with the physical execution layer through communication protocols, supporting virtual-real collaborative control and fault simulation.

[0017] Further, the stereoscopic warehouse module adopts four-layer shelf configuration of 12 storage locations, including 6 raw material warehouses and 6 finished product warehouses, and each storage location is provided with a positioning tool.

[0018] Further, the robot comprises two six-degree-of-freedom industrial robots, realizing the in-out operation and visual detection cooperation operation.

[0019] Further, the visual detection station executes a four-state decision mechanism:

[0020] (1) When the detection station P1 is idle, the robot places the workpiece on the conveying line to the detection station P1;

[0021] (2) When the detection station P1 is occupied and the temporary storage station P2 is idle, the robot first moves the workpiece in the detection station P1 to the temporary storage station P2, and then places the new workpiece in the detection station P1;

[0022] (3) When the detection station P1 and the temporary storage station P2 are both occupied, the system alarm is triggered.

[0023] Further, the control layer integrates the following functional modules:

[0024] (a) System state monitoring module: real-time display of device communication state, sensor signal and emergency stop state;

[0025] (b) Process flow tracking module: visual display of the whole process of out-of-warehouse→conveying→detection→warehousing;

[0026] (c) Stereoscopic warehouse management module: realizing three-dimensional mapping of storage location state;

[0027] (d) Visual detection interface module: real-time display of visual recognition results;

[0028] (e) Production line debugging interface module: executing start / stop / reset operation and production line parameter adjustment.

[0029] Further, the stereoscopic warehouse executes a color priority warehousing strategy, assigns storage locations according to a pre-defined color-storage location mapping rule, and ignores low-order number idle storage locations.

[0030] A virtual-real collaborative control method based on the system, comprising the following steps:

[0031] (1) Virtual debugging is performed at the digital twin layer, and control instructions are generated;

[0032] (2) The physical execution layer starts the pre-execution safety check;

[0033] (3) The ring-shaped conveying line operates at a set reference frequency, and the positioning mechanism realizes accurate positioning of the tool plate through sequential action.

[0034] Further, in step (2), the safety check includes: confirming the safety of the robot pose, the idle state of at least one vision station, and the configuration check of the material in the warehouse.

[0035] Further, the configuration check of the material in the warehouse needs to meet the minimum configuration condition:

[0036] There are ≥1 warehouse positions in the warehouse position that store tool plates with materials;

[0037] There are ≥2 color corresponding warehouse positions in the warehouse position that remain empty.

[0038] Further, in step (3), the reference frequency is 40Hz.

[0039] Further, in step (3), the action timing sequence of the positioning mechanism is:

[0040] After the tool plate reaches the station, the blocking mechanism first acts;

[0041] After a delay of 2 seconds, the lifting mechanism acts.

[0042] Advantages: Compared with the prior art, the present application has the following advantages:

[0043] 1. Combination of virtual and real, improving the effect of practical training: through the digital twin technology, the combination of virtual simulation and physical operation is realized, students can repeatedly practice in the virtual environment, and then verify in the physical production line, reducing the cost and equipment damage risk of practical training.

[0044] 2. Strong scalability: the system hardware can be expanded with numerical control lathes, numerical control milling machines, AGVs and other equipment, and the software can add more practical training projects and simulation scenes to meet different teaching needs.

[0045] 3. High safety: the virtual simulation environment can simulate various faults and dangerous working conditions, students can learn to respond in a safe virtual environment, improve safety awareness and emergency handling ability.

[0046] 4. Rich teaching resources: the digital twin model can be reused, supporting multiple people to train at the same time, solving the problem of insufficient number of traditional practical training equipment, and providing rich simulation data and visual interface for teaching and evaluation. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 is a top view of the intelligent manufacturing production line practical training system based on digital twinning;

[0048] Figure 2 is a schematic diagram of a double positioning unit structure of the ring-shaped conveying line in the physical execution layer;

[0049] Figure 3 is a four-state decision logic flowchart;

[0050] Figure 4 is a color-bin mapping rule schematic diagram;

[0051] Figure 5 is a general control interface function partition diagram;

[0052] Figure 6 is a three-layer system architecture diagram;

[0053] Figure 7 is a virtual-real data interaction timing diagram. DETAILED DESCRIPTION

[0054] The application will be further explained below in conjunction with the accompanying drawings.

[0055] The intelligent manufacturing production line practical training system based on digital twinning of the application is composed of a physical production line and a digital twinning simulation system, adopts a three-layer architecture, and includes a physical execution layer, a control layer, and a digital twinning layer, as shown in the accompanying drawings. Figure 6 The application realizes virtual-real data interaction through network communication.

[0056] The physical execution layer includes hardware devices such as a stereoscopic warehouse, a ring-shaped conveying line, a visual detection table, a robot, and a general control system, and each device is collaboratively controlled through a PLC master control unit and an industrial network of the control layer. Among them:

[0057] The stereoscopic warehouse adopts an aluminum profile four-layer shelf, has a total of 12 bins, 6 raw material bins, and 6 finished product bins, and each bin is equipped with a positioning tool and a bin detection sensor.

[0058] The ring-shaped conveying line is driven by a variable frequency motor, contains double positioning units, and is respectively an in-out bin station positioning unit and a visual detection station positioning unit. Each positioning unit contains a blocking detection sensor, a jacking detection sensor, a blocking air cylinder, and a jacking air cylinder.

[0059] The visual detection table is composed of an industrial camera, a lens, a light source, a detection positioning table, and a visual algorithm platform software, and sets a detection site and a temporary storage site.

[0060] The robot adopts two six-degree-of-freedom industrial robots to realize in-out bin operation and visual detection cooperation operation.

[0061] In a preferred embodiment, asFigure 1 As shown in the figure, the physical execution layer includes the general control system 1, the visual detection station 2, the visual position industrial robot 3, the visual position tool positioning mechanism 4, the in-out warehouse position tool positioning mechanism 5, the in-out warehouse position industrial robot 6, the raw material warehouse 7 and the finished product warehouse 8.

[0062] In a preferred embodiment, as shown in the figure, the double positioning unit structure of the ring-shaped conveying line includes the workpiece detection switch 11, the tool plate detection switch 12, the jacking air cylinder 13 and the blocking air cylinder 14. Figure 2

[0063] The control layer includes the PLC master control unit and the human-computer interaction unit, and is used for realizing device collaborative control and operation monitoring. The human-computer interaction unit adopts a touch screen. The control layer integrates five function modules, as shown in Table 1, which are respectively: system state monitoring, process flow tracking, three-dimensional warehouse management, visual detection interface and production line debugging interface. The function partition diagram of the control layer interface is as shown in the figure. Figure 5

[0064] Table 1

[0065] Module name Function System state monitoring Real-time display of equipment communication state / sensor signal / emergency stop state Process flow tracking Visual display of the entire process from warehouse to transport to detection to warehouse Management of a stereoscopic warehouse Three-dimensional mapping of the state of the warehouse Visual detection interface Real-time display of visual recognition results Production line debugging interface Start / stop / reset, production line parameter adjustment

[0066] The digital twin layer is based on a development platform such as Unity, and a 1:1 three-dimensional virtual model is constructed. The geometric size and motion parameters of the model are consistent with those of each device in the physical layer. The production line layout simulation, process simulation, fault simulation and the like can be realized. Through a communication protocol such as OPCUA, sensor data (such as warehouse position detection signals, conveying line running states, robot poses and the like) of the physical system are acquired in real time to drive the virtual model to run; at the same time, operation instructions (such as start-stop instructions, process parameter adjustments and the like) of the virtual model can be sent to the physical system to realize two-way control.

[0067] In the present application, the visual detection station executes a four-state decision mechanism:

[0068] The visual station sets a detection station P1 and a temporary storage station P2, and drives the robot to act through a sensor combination state, as shown in the figure and Table 2. Compared with a single station design, the efficiency is improved by 35%. Figure 3

[0069] Table 2

[0070] P1 state P2 state Robot action sequence 0 0 Take the workpiece from the transport line → P1 0 1 Take the workpiece from the transport line → P1 1 0 Move the P1 workpiece → P2 → take the workpiece from the transport line → P1 1 1 Trigger alarm, wait for manual intervention

[0071] In the present application, the three-dimensional warehouse executes a color priority storage strategy, and allocates warehouse positions according to a pre-defined color-warehouse mapping rule, ignoring low-order idle warehouse positions. As shown in the figure. Figure 4

[0072] In the present application, the virtual-real collaborative control process is as follows:

[0073] ​​​​The line virtual debugging is performed at the digital twin layer, control instructions are generated, the control instructions are sent to the PLC, the PLC controls the physical layer equipment to perform actions, sensor data of the physical equipment is returned to the PLC, the PLC sends the data to the digital twin layer, and the digital twin layer updates the model state in real time.

[0074] A virtual-real collaborative control method based on the system comprises the following steps:

[0075] (1) Virtual debugging is performed at the digital twin layer and control instructions are generated;

[0076] (2) The physical execution layer starts to perform safety interlocking;

[0077] The safety interlocking includes confirming the safety of the robot pose, the idle state of at least one work station of the vision work station, and the configuration check of the warehouse position materials.

[0078] The configuration check of the warehouse position materials needs to meet the minimum configuration condition:

[0079] There are more than one warehouse positions with material tooling plates in the warehouse-out position;

[0080] There are more than two colors corresponding to the warehouse positions that remain empty in the warehouse-in position.

[0081] (3) The ring conveying line runs at a set reference frequency, and the tooling plate is accurately positioned through the positioning mechanism of sequential action;

[0082] The reference frequency is 40 Hz.

[0083] The action timing sequence of the positioning mechanism is:

[0084] After the tooling plate reaches the work station, the blocking mechanism first acts;

[0085] The jacking mechanism acts after a delay of 2 seconds.

[0086] Embodiment

[0087] This embodiment takes the whole workpiece sorting process as an example.

[0088] 1. Virtual rehearsal:

[0089] The yellow workpiece is set at the digital twin layer -> 4-6 warehouse position rule;

[0090] The simulation vision detection table P1 occupies the state, and the logic of the robot moving to P2 is verified.

[0091] 2. Physical execution, as shown in Figure 7 The following steps are included:

[0092] (1) The ring conveying line runs at a reference frequency of 40 Hz, driving the tooling plate to the warehouse-in and warehouse-out work station;

[0093] (2) The access and storage station blocking cylinder operates, the lifting cylinder operates after 2s, and the access and storage robot takes the workpiece in No. 1 storage station;

[0094] (3) The tooling plate is conveyed to the visual inspection station;

[0095] (4) The visual inspection station blocking cylinder operates, and the lifting cylinder operates after 2s;

[0096] (5) P1 is detected to be occupied and P2 is idle, the robot moves the P1 workpiece to P2, and a new workpiece is placed in P1;

[0097] (6) The visual inspection identifies yellow, and color coding is written;

[0098] (7) The tooling plate is conveyed to the access and storage station again;

[0099] (8) The access and storage station blocking cylinder operates, the lifting cylinder operates after 2s, the access and storage robot receives a signal, and the workpiece is placed in No. 5 storage station (skipping the idle No. 2 storage station).

[0100] The above only describes the preferred embodiments of the present application, and it should be noted that, for those skilled in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered within the protection scope of the present application.

Claims

1. A training system for intelligent manufacturing production lines based on digital twins, characterized in that: Comprise: Physical execution layer: including a stereoscopic warehouse for workpiece storage and positioning, a ring-shaped conveying line for workpiece flow, a visual detection station for workpiece identification, and a robot for workpiece transfer; The stereoscopic warehouse is provided with partitioned shelves and storage location detection sensors; The ring-shaped conveying line is provided with an in-out warehouse station positioning unit and a visual detection station positioning unit, each unit being provided with a blocking mechanism, a jacking mechanism and a corresponding detection sensor; The visual detection station is provided with a detection station P1 and a temporary storage station P2; Control layer: including a PLC main control unit and a human-computer interaction unit, for realizing equipment collaborative control and operation monitoring; Digital twin layer: including three-dimensional virtual models corresponding to each device in the physical execution layer, realizing bidirectional data interaction with the physical execution layer through a communication protocol, supporting virtual-real collaborative control and fault simulation.

2. The system of claim 1, wherein: The stereoscopic warehouse module adopts four-layer shelves to configure 12 storage locations, including 6 raw material warehouses and 6 finished product warehouses, and each storage location is provided with a positioning tool.

3. The system of claim 1, wherein: The robot comprises two six-degree-of-freedom industrial robots.

4. The system of claim 1, wherein: The visual detection station executes a four-state decision mechanism: (1) When the detection station P1 is idle, the robot places the workpiece on the conveying line to the detection station P1; (2) When the detection station P1 is occupied and the temporary storage station P2 is idle, the robot first moves the workpiece in the detection station P1 to the temporary storage station P2, and then places the new workpiece in the detection station P1; (3) When the detection station P1 and the temporary storage station P2 are both occupied, the system triggers an alarm.

5. The system of claim 1, wherein: The control layer integrates the following functional modules: (a) System state monitoring module: real-time display of device communication state, sensor signal and emergency stop state; (b) Process flow tracking module: visual display of the whole process of out-of-warehouse → conveying → detection → in-warehouse; (c) Stereoscopic warehouse management module: realizing three-dimensional mapping of storage location state; (d) Visual detection interface module: real-time display of visual recognition results; (e) Production line debugging interface module: executing start / stop / reset operations and production line parameter adjustment.

6. The system of claim 1, wherein: The stereoscopic warehouse executes a color priority in-warehouse strategy, assigns storage locations according to a pre-defined color-storage location mapping rule, and ignores low-number idle storage locations.

7. A virtual-real collaborative control method based on the system of claim 1, characterized in that: The method comprises the following steps: (1) Virtual debugging is performed in the digital twin layer to generate control instructions; (2) Before the physical execution layer is started, a safety joint inspection is performed; (3) The ring-shaped conveying line runs at a set reference frequency, and the positioning mechanism realizes precise positioning of the tool plate through sequential actions.

8. The method of claim 7, wherein: In step (2), the safety joint inspection includes: confirming the safety of the robot pose, the idle of at least one visual station, and the material configuration check of the storage location.

9. The method of claim 8, wherein: The material configuration check of the storage location needs to meet the minimum configuration condition: There are ≥1 storage locations with material tool plates in the out-of-warehouse location; The storage location corresponding to ≥2 colors is kept empty.

10. The method of claim 7, wherein: In step (3), the reference frequency is 40 Hz, and the action timing sequence of the positioning mechanism is: After the tooling plate reaches the station, the blocking mechanism first acts; The lifting mechanism acts after a 2-second delay.

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