Digital twinning simulation system and simulation method based on automobile production running and stopping line

Abstract

The invention relates to the field of automobile flow line production, in particular to a digital twinning simulation system based on an automobile production running and stopping line, which comprises a production control system, an internet of things system and a digital twinning system. The production control system controls production equipment and sends sensing information to the Internet of Things system. And the Internet of Things system generates production line state information based on the integrated sensing information and sends the production line state information to the digital twin system. The production line state information comprises release information, vehicle transfer information and occupation information of each post on the production line. And the digital twinning system judges whether conflicts exist or not by using the state information of the production line, and then updates and displays the state of the virtual production line, so that the twinning effect of the virtual production line is realized. The invention also comprises a method. According to the method, the production line control signal is combined with the sensing signal and does not depend on an occupation signal any more, so that the vehicle position can be calculated in advance, it is ensured that digital simulation and the actual situation of on-site vehicle movement are kept synchronous, and meanwhile the problem that vehicles disappear in queue data is solved.

Description

Technical Field

[0001] The present invention relates to the field of automobile assembly line production, and in particular to a digital twin simulation system and a simulation method based on an automobile production start-stop line. Background Art

[0002] At present, the common stop-and-go line simulation method for automotive digital twins is to drive it through the vehicle fleet provided by the enterprise's MES system. When the vehicle fleet changes, the vehicle displayed on the digital twin screen moves to the next position. In the prior art, the occupancy sensors set at each position are used to indirectly infer the vehicle position, thereby updating the virtual production line queue.

[0003] For example, in the real environment, when a vehicle leaves the preceding position and enters the following position, the vehicle queue in the production control system changes, and the occupancy sensor at the following position detects the vehicle. At this time, the IoT system collects occupancy sensor information at a fixed frequency, detects changes in the vehicle queue, and pushes the changed data to the digital twin system. The digital twin system receives the data change, and because it finds that the signal of the vehicle at the preceding position disappears and there is a vehicle signal at the following position, it updates the virtual production line and moves the vehicle forward one station. The defects of this type of method are: 1. Because the digital twin system mainly relies on arrival occupancy queue data, the vehicle movement process animation in the digital twin system will be delayed compared to the actual production line.

[0004] 2. When the IoT system collects signals regularly, if the vehicle is between two positions, the vehicle will disappear from the queue data in the digital twin system. The vehicle needs to fully enter the subsequent position to correctly synchronize the vehicle information, causing inconsistency between the digital twin and the site. Summary of the invention

[0005] The purpose of the present invention is to provide a digital twin simulation system and simulation method based on the automobile production stop-and-go line, which solves the problems existing in the above-mentioned prior art by increasing the collection of control signals such as job motors and limiters and updating the virtual queue algorithm.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is to provide a digital twin simulation system based on the automobile production stop-and-go line, forming a virtual production line that is a twin of the real production line that applies the stop-and-go line process, and is used for remote real-time management of vehicle production on the production line, characterized in that it includes a production control system, an Internet of Things system and a digital twin system; The production control system is connected to the production line, drives the vehicle to pass through one or more positions along the production line, and controls the production equipment installed at the position to complete the production process corresponding to the position for the vehicle; the production control system also sends sensor information to the Internet of Things system; the Internet of Things system generates production line status information based on the sensor information and sends it to the digital twin system; the production line status information includes release information, vehicle transfer information and occupancy information of each position on the production line; The digital twin system combines the release information and the vehicle transfer information to calculate the virtual queue information, and further updates and displays the virtual production line status based on the virtual queue information, thereby achieving the twin effect of the virtual production line; the digital twin system determines whether there is a conflict based on the occupancy information and the virtual queue information, and issues an alarm through the virtual production line when the conflict occurs.

[0007] Further, the production control system comprises a control module and a sensor module; The control module is connected to the production line and the production equipment, and sends control information to the production line and the production equipment to control the actions of the production line and the production equipment. At the same time, the sensor information is generated based on the control information and sent to the Internet of Things system; the sensor module is connected to the production line, collects sensor signals, converts them into the sensor information, and sends them to the Internet of Things system.

[0008] Furthermore, the sensing module is connected to an occupancy sensor; the occupancy sensor corresponds to the post one by one and is installed next to the post; the sensing module generates the sensing information representing whether the vehicle exists at the post according to the signal of the occupancy sensor.

[0009] Further, the control module includes a limiter control submodule and a motor control submodule; The stopper control submodule is connected to the stopper; the stopper corresponds to the position one by one, and is used to release the vehicle corresponding to the position; the stopper control submodule controls the action of the stopper according to production needs, and generates the sensor information indicating whether to release the vehicle at the current position; The motor control submodule is connected to the motor on the production line, and controls the motor movement according to production needs, thereby driving the vehicle to enter the production line or move along the production line, and generating the sensor information representing the transfer of the vehicle.

[0010] Furthermore, the motor control submodule is connected to the elevator motor and the post motor; the elevator motor is used to lift the vehicle into the production line; when the elevator motor is activated, the sensor information representing the new vehicle on the line is generated; the post motor is used to drive the vehicle along the production line to the next post, or leave the production line; when the post motor is activated, the sensor information representing the movement of the existing vehicles is generated.

[0011] Furthermore, the Internet of Things system includes a data acquisition module, a data storage module, a data calculation module and a data communication module; The data acquisition module uses the data communication module to obtain the sensor information from the production control system and delivers it to the data calculation module; the data calculation module uses the data storage module to integrate the sensor information, generate the production line status information, and finally transmits the production line status information to the digital twin system through the data communication module.

[0012] Furthermore, the digital twin system includes a data preprocessing module, a data calculation module, a queue data module, a drive logic module and an animation module; The data preprocessing module performs format conversion on the received production line status information and sends it to the data calculation module; the data calculation module generates production line event information based on the production line status information and sends it to the queue data module; The queue data module records the changes of the vehicles on and off the line, and uses the production line event information to update the virtual queue information; when the virtual queue information changes, the drive logic module is notified and the virtual queue information is sent to the drive logic module; The driving logic module maintains the virtual production line status. When receiving the virtual queue information, it updates the virtual production line status based on the virtual queue information and sends it to the animation module. The animation module updates the animation according to the virtual production line status, generates a visualized virtual production line and displays it.

[0013] The present invention also discloses a simulation method using the digital twin simulation system based on the automobile production start-stop line, which is characterized by comprising the steps of: Step S10, initializing the production control system, the Internet of Things system and the digital twin system; in the queue data module in the digital twin system, establishing a virtual queue and initializing all cells in the virtual queue to be empty; Step S20, the production control system controls the vehicle to enter the production line; Step S30, the production control system collects and reports the sensor information to the Internet of Things system; Step S40, the IoT system converts the information into production line status information and sends it to the digital twin system; Step S50, the digital twin system determines whether there is a conflict based on the production line status information and the current virtual queue information; if a conflict occurs, the digital twin system issues an alarm to prompt the production line conflict, otherwise it goes to step S60; Step S60, the queue data module calculates new virtual queue information based on the production line status information; Step S70, when the virtual queue information changes, the digital twin system updates the virtual production line status; Step S80, the digital twin system updates the animation according to the state of the virtual production line and displays the virtual production line; Step S90, the vehicle completes the production process at the current position, and the production control system controls the vehicle to enter the next position; if there is no new vehicle entering the production line at present, jump to step S30; otherwise jump to step S20.

[0014] Furthermore, in step S50, the step of determining the production line conflict includes the following sub-steps: Step S51, reading the release information and the vehicle transfer information in the production line status information, if a new vehicle is on the line, marking the target unit as the first unit in the virtual queue; if an existing vehicle is moving, marking the target unit as the unit corresponding to the next position of the vehicle; if the vehicle is located at the last unit in the virtual queue, determining that there is no conflict, and jumping to step S53; Step S52, reading the occupancy information in the production line status information, and if there is a vehicle occupying the target unit, determining that there is a conflict; otherwise, determining that there is no conflict; Step S53, complete the conflict detection and report the determination result.

[0015] Furthermore, the step of calculating the new virtual queue information in step S60 includes the following sub-steps: Step S61, reading the release information and the vehicle transfer information in the production line status information, if it is a new vehicle on the line, proceed to step S62; if it is a stock vehicle moving, proceed to step S63; otherwise, jump to step S66; Step S62, fill the vehicle information corresponding to the new vehicle into the first unit of the virtual queue, and proceed to step S66; Step S63, if the cell at the end of the virtual queue is not empty, remove the vehicle information from the cell; Step S64, moving the vehicle information in each unit in the virtual queue to the next unit; Step S65, clearing the vehicle information in the first unit in the virtual queue; Step S66: Generate the virtual queue information based on the virtual queue.

[0016] In view of the above technical features, the present invention solves the problem that the vehicle queue of the stop-and-go line is later than the actual situation on site based on the digital twin simulation system and simulation method of the automobile production stop-and-go line. Compared with the prior art, the present invention has the following advantages: 1. The present invention utilizes production line control signals in combination with sensor signals and utilizes a queue data module to calculate vehicle positions in advance, thereby ensuring that digital simulation is synchronized with the actual conditions of on-site vehicle movement.

[0017] 2. The present invention does not completely rely on the signal of the occupancy sensor, thereby solving the problem of missing vehicles in the queue data. Because the change of the vehicle queue no longer depends on the occupancy signal, but is combined with the production line control signal, even if the vehicle is between two positions, the vehicle will not be lost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a system block diagram of a preferred embodiment of the digital twin simulation system based on the automobile production start-stop line of the present invention; Figure 2 It is a production line schematic diagram of a production control system in a preferred embodiment of the digital twin simulation system based on an automobile production start-stop line of the present invention; Figure 3 It is a method flow chart of a preferred embodiment of the simulation method of the digital twin simulation system based on the automobile production start-stop line of the present invention.

[0019] In the figure: 100-production control system, 200-Internet of Things system, 300-digital twin system; 110-control module, 120-sensor module; 111-limiter control submodule, 112-motor control submodule, 113-limiter, 114-post motor, 115-elevator motor, 121-occupancy sensor; 201-data acquisition module, 202-data calculation module, 203-data storage module, 204-data communication module; 301 - data preprocessing module, 302 - data calculation module, 303 - queue data module, 304 - driving logic module, 305 - animation module. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0021] See also Figure 1 and Figure 2 The present invention discloses a digital twin simulation system based on a stop-and-go line for automobile production. It corresponds to a real production line that applies the stop-and-go line process, and forms a twin virtual production line according to the state of the real production line. In this way, production line managers can remotely learn about the situation of the real production line in real time and remotely manage vehicle production on the real production line. A preferred embodiment of the system is composed of a production control system 100, an Internet of Things system 200, and a digital twin system 300.

[0022] In the actual production line that applies the stop-go line process, multiple positions are generally set up. Production equipment is installed at each position. After the vehicle to be processed enters from the entrance of the production line, it passes through each position in turn. When the vehicle arrives at the position, it will make a short stop. During the vehicle's stop, the workers at the position will use production equipment or automated production equipment to process the vehicle and complete the production process corresponding to the current position. When a vehicle completes all production processes at the current position, it will be driven to continue along the production line, arrive at the next position, and repeat the previous actions until the vehicle has passed through all the positions on the production line, that is, completed all the production processes corresponding to this production line, and finally left the production line.

[0023] The production control system 100 is connected to the real production line, and it includes a control module 110 and a sensor module 120. The control module 110 is used to control the production line and the production equipment. It is connected to the production line and the production equipment and sends control information to the production line and the production equipment according to the production plan. After receiving the control information, the production line will drive the vehicle to move between the positions. After receiving the control information, the production equipment that supports automated production will process the vehicle that stays at the position to complete the production process. At the same time, the control module 110 will also generate sensor information based on the control information generated, which will be collected by the Internet of Things system 200.

[0024] Specifically, the control module 110 includes a limiter control submodule 111 and a motor control submodule 112. Among them, the limiter control submodule 111 is connected to the limiter 113 installed on the production line. The limiter 113 corresponds to the position one by one, and is installed at the exit of each position. It is used to release the vehicle at the corresponding position. When the vehicle completes the production process at the current position, the limiter control submodule 111 sends a control instruction to the limiter 113, and then the limiter 113 acts, and the production line can continue to operate, thereby transferring the vehicle to the next position. If the limiter 113 does not release, the vehicle will stay at the current position. While controlling the action of the limiter 113, the limiter control submodule 111 records the event that the current limiter 113 is released, and generates sensor information based on this and transmits it to the Internet of Things system 120. The motor control submodule 112 connects and controls the motor on the production line. On the production line, there are two types of motors: elevator motors 115 and position motors 114. Among them, the elevator is located at the entrance of the production line and is driven by the elevator motor 115. The post motor 114 is used to drive the production line forward, thereby driving the vehicle to move between posts. According to production needs, when a new vehicle needs to enter the production line, the motor control submodule 112 sends a control command to the elevator motor 115, operates the elevator motor 115, and lifts the vehicle to the entrance of the production line. When a vehicle needs to be transferred between posts, including transferring the vehicle from the production line entrance to the first post, the motor control submodule 112 sends a control command to the corresponding post motor 114, operates the corresponding post motor 114, and drives the vehicle along the production line. Regardless of whether the elevator motor 115 or the post motor 114 is in action, the motor control submodule 112 records the corresponding event and generates sensor information based on it and transmits it to the Internet of Things system 120. Corresponding to the elevator action, the motor control submodule 112 generates a new car online signal as sensor information. Corresponding to the post motor 114 action, the motor control submodule 112 generates a vehicle movement signal as sensor information.

[0025] The sensor module 120 itself does not control the production line or production equipment, and cannot manipulate their actions. The sensor module 120 is generally connected to the sensors installed on the production line, collects sensor signals, and converts sensor information, which is collected by the Internet of Things system 200. In this embodiment, the sensor module 120 is connected to the occupancy sensor 121. The occupancy sensors 121 are installed at each position, and their number is consistent with the number of positions on the production line, and they have a one-to-one correspondence with the positions. The function of the occupancy sensor 121 is to sense whether there is a vehicle at the corresponding position, and it is generally implemented as a photoelectric sensor. The signal reported by the occupancy sensor 121 to the sensor module 120 is an analog signal, which is converted by the sensor module 120 into digital vehicle occupancy information and becomes sensor information that can be recognized by the Internet of Things system 200.

[0026] The production control system 100 contains a large number of control signals for controlling the production of the real production line and sensor signals reflecting various states of the real production line, but the digital twin system 300 does not actually need all of the sensor signals. At the same time, the equipment in the production control system 100 will also be updated as the production line is updated, and the format of the sensor signals reported by it will also change accordingly. Therefore, the Internet of Things system 200 is introduced and placed between the production control system 100 and the digital twin system 300. The Internet of Things system 200 only extracts the sensor signals required by the digital twin system 300 from the production control system 100, and sends them to the digital twin system 300 after regularizing their formats. In this way, when there are equipment changes in the production control system 100, the Internet of Things system 200 can be used to isolate the differences, maintain the stability of the digital twin system 300, and improve the reliability of the digital twin system 300. The Internet of Things system 200 includes a data acquisition module 201, a data calculation module 202, a data storage module 203, and a data communication module 204. The data communication module 204 is a unified interface for the Internet of Things module 200 to exchange information with the outside world. It is used for data communication with the production control system 100 and for data communication with the digital twin system 300. The data acquisition module 201 is the entrance of the Internet of Things system 200. It uses the data communication module 204 to read the sensor information from the production control system 100 and deliver it to the data calculation module 202. The data calculation module 202 is used to complete the data format conversion. The data calculation module 202 uses the data storage module 203 to complete the data conversion work: the sensor information is saved in the data storage module 203, and then the sensor information is formatted in the data storage module 203 to generate the production line status information. After completing the data conversion, the data calculation module 202 still uses the data communication module 204 to transmit the production line status information to the digital twin system 300. The production line status information includes the release information, vehicle transfer information and occupancy information of each position on the production line. Specifically, the sensor information from the limiter 113 generates the corresponding release information. The new vehicle on-line signal from the lifting motor and the vehicle movement signal from the post motor 114 generate different vehicle transfer information, corresponding to the new vehicle on-line and the movement of the stock vehicle. The sensing information from the occupancy sensor 121 generates occupancy information.

[0027] The digital twin system 300 reads the product status information sent from the Internet of Things system 200, and then generates an animation showing the status of the virtual production line based on the product status information, and displays it to the production line manager. The virtual production line can be displayed remotely, so that managers can obtain the status of the real production line remotely, especially in the scenario of multiple production lines, so that production can be managed more effectively. The digital twin system 300 includes a data preprocessing module 301, a data calculation module 302, a queue data module 303, a drive logic module 304 and an animation module 305.

[0028] The data preprocessing module 301 receives the production line status information, performs necessary format conversion according to the requirements of the internal modules of the digital twin system 300, and then sends the corrected production line status information to the data calculation module 302. The data calculation module 302 reads the release information, vehicle transfer information and occupancy information from the production line status information, generates production line event information, and sends it to the queue data module 303. Specifically, when a new car is on the line (elevator signal) and there is a vehicle movement signal at the first post, it is determined that a new car has entered the production line, and the production line event information of the new car entering the line is generated. When a release signal of a post and a vehicle movement signal of the next post are received, the production line event information of the vehicle entering the corresponding next post is generated. In the process of generating the production line event information, the data calculation module 302 will use the occupancy signal to determine whether there is a conflict. For example, if there is an occupancy signal reported at the post to be entered, it means a production line conflict. At this time, the data calculation module 302 will issue an alarm to notify the production line management personnel to handle it.

[0029] A virtual queue will be established in the queue data module 303, and each unit in the virtual queue corresponds to each position on the virtual production line. When vehicle information is filled in the unit, it means that there is a vehicle at the current position in the virtual queue. Conversely, when the unit is empty, it means that there is no vehicle at the corresponding position on the virtual production line. The queue data module 303 is driven by the production line event information from the data calculation module 302. When new production line event information is received, the queue data module 303 updates the unit information in the virtual queue, thereby completing the changes in vehicle on and off the line and vehicle movement. After processing the production line event information, the queue data module 303 will determine whether the current virtual queue information has changed, and only when the virtual queue information changes, send the virtual queue information to the drive logic module 304, thereby notifying the drive logic module 304.

[0030] The virtual production line is different from the real production line. In the real production line, the actual motor controls the operation of the production line. In the virtual production line, the virtual production line status is maintained by the drive logic module 304. The drive logic module 304 sets the drive logic according to the virtual queue information, including various flags of the virtual production line, so as to change the virtual production line status. For example, if it is found that all vehicles in the virtual queue have entered the next position, the flag blocking the operation of the virtual production line is cancelled, so that the animation module 305 starts to display the picture of the vehicle moving forward on the virtual production line. When the vehicle position 1 displayed on the animation module 305 is consistent with that in the virtual queue, the flag blocking the operation of the virtual production line is reset, so that the vehicle in the animation stops at the current position, which is consistent with the real production line, forming a twin effect. After the drive logic module 304 updates the drive logic, the animation module 305 generates a new animation to reflect the latest virtual production line status, and then displays it visually to the production line management personnel.

[0031] See also Figure 3 The present invention also discloses a simulation method using the digital twin simulation system based on the automobile production start-stop line. A preferred embodiment thereof comprises the steps of: Step S100, initializing each system.

[0032] Before production starts, the production control system, IoT system and digital twin system are initialized. In particular, the queue data module in the digital twin system establishes a virtual queue during the initialization phase. After initialization, the virtual queue contains the same number of units as the positions on the real production line, and all units are set to empty, which means that there are no vehicles on the current virtual production line.

[0033] Step S200: The vehicle enters the production line.

[0034] Under the control of the production control system, the vehicle is lifted by the elevator to the entrance of the production line, and then the motor corresponding to the first position works to push the vehicle from the entrance to the first position and then stop.

[0035] Step S300: the production control system reports sensor information.

[0036] The production control system generates sensor information based on the control information sent by the control module, such as new vehicle on-line signal, vehicle movement signal, and limiter release signal. At the same time, the production control system uses the sensor module to collect the signal of the occupancy sensor and generates occupancy information as sensor information. All sensor information is transmitted and reported to the Internet of Things system.

[0037] Step S400: The Internet of Things system reports production line status information.

[0038] After receiving the sensor information, the IoT system converts it into production line status information that can be recognized by the digital twin system and sends it to the digital twin system.

[0039] Step S500: The data calculation module in the digital twin system performs conflict determination based on the production line status information.

[0040] Step S501, marking the target unit.

[0041] Read the release information and vehicle transfer information in the production line status information. If a new vehicle is online, mark the target unit as the first unit in the virtual queue.

[0042] If it is a stock vehicle moving, the target cell is marked as the cell corresponding to the next position of the vehicle.

[0043] If the vehicle is located at the last unit in the virtual queue, it is determined that there is no conflict, and the process jumps to step S503.

[0044] Specifically, if the production line status information contains the movement of the elevator motor, then a new car is on the line. If the production line status information contains the movement of the post motor, then the stock vehicle is moving.

[0045] Step S502: determine whether there is a conflict in the target unit according to the placeholder information.

[0046] Read the occupancy information in the production line status information. If there is a vehicle occupying the target unit, it is determined that there is a conflict, otherwise it is determined that there is no conflict.

[0047] Step S503, determining whether to issue an alarm based on the conflict detection result.

[0048] If there is a conflict, the digital twin system will issue an alarm to indicate the production line conflict.

[0049] Step S600: The digital twin system updates the virtual queue information.

[0050] The queue data module calculates new virtual queue information based on the production line status information.

[0051] Step S601, distinguishing between new vehicles coming online and the movement of existing vehicles.

[0052] Read the release information and vehicle transfer information in the production line status information. If it is a new vehicle on the line, go to step S602. If it is a stock vehicle moving, go to step S603; otherwise, jump to step S606.

[0053] Specifically, if the production line status information contains the movement of the elevator motor, then a new car is on the line. If the production line status information contains the movement of the post motor, then the stock vehicle is moving.

[0054] Step S602, update new car information.

[0055] Fill the vehicle information corresponding to the new vehicle into the first cell of the virtual queue and proceed to step S606.

[0056] Step S603, updating the vehicle offline.

[0057] If the cell at the end of the virtual queue is not empty, the vehicle information is removed from the last cell, that is, the content of the last cell is empty.

[0058] Step S604, updating the movement of existing vehicles.

[0059] Move the vehicle information in each unit in the virtual queue to the next unit, that is, move the vehicle to the next position in the corresponding virtual production line.

[0060] Step S605, updating the first unit data.

[0061] Clear the vehicle information in the first unit of the virtual queue. Since all vehicles have moved back one position, the first unit is free and can receive new vehicles.

[0062] Step S606: Generate virtual queue information.

[0063] The virtual queue is only visible inside the queue data module. In the digital twin system, other modules generate virtual queue information based on the virtual queue through the queue data module and learn the details of the current virtual queue. When the unit in the virtual queue changes, the queue data module generates new virtual queue information.

[0064] Step S700, updating the virtual production line status.

[0065] When the virtual queue information changes, the drive logic module in the digital twin system will be activated. The drive logic module will update the drive logic used to control the virtual production line according to the new virtual queue information, thereby adjusting the state of the virtual production line.

[0066] Step S800: update and display the virtual production line animation.

[0067] The animation module in the digital twin system recognizes the change in the virtual production line status, generates a new animation based on the new virtual production line status, and then displays it to the production line manager. At this point, the status of the real production line is displayed to the production line manager by the virtual production line twin.

[0068] Step S900: the vehicle completes the production process.

[0069] After the vehicle completes all production processes at the current position, the production control system controls the vehicle to enter the next position. If there is no new vehicle that needs to enter the production line, jump to step S300, otherwise jump to step S200.

[0070] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A digital twin simulation system based on the automobile production stop-start line forms a virtual production line that is a twin of the real production line that applies the stop-start line process, and is used for remote real-time management of vehicle production on the production line, characterized in that: Includes production control systems, IoT systems and digital twin systems; The production control system is connected to the production line, drives the vehicle to pass through one or more positions along the production line, and controls the production equipment installed at the position to complete the production process corresponding to the position for the vehicle; the production control system also sends sensor information to the Internet of Things system; the Internet of Things system generates production line status information based on the sensor information and sends it to the digital twin system; the production line status information includes release information, vehicle transfer information and occupancy information of each position on the production line; The digital twin system combines the release information and the vehicle transfer information to calculate the virtual queue information, and further updates and displays the virtual production line status based on the virtual queue information, thereby achieving the twin effect of the virtual production line; the digital twin system determines whether there is a conflict based on the occupancy information and the virtual queue information, and issues an alarm through the virtual production line when the conflict occurs.

2. The digital twin simulation system based on the automobile production start-stop line according to claim 1 is characterized in that: The production control system comprises a control module and a sensor module; The control module is connected to the production line and the production equipment, sends control information to the production line and the production equipment, thereby controlling the actions of the production line and the production equipment, and generates the sensor information based on the control information and sends it to the Internet of Things system; The sensor module is connected to the production line, collects sensor signals, converts them into the sensor information, and sends them to the Internet of Things system.

3. The digital twin simulation system based on the automobile production start-stop line according to claim 2 is characterized in that: The sensing module is connected to an occupancy sensor; the occupancy sensor corresponds to the post one by one and is installed next to the post; the sensing module generates the sensing information representing whether the vehicle exists at the post according to the signal of the occupancy sensor.

4. The digital twin simulation system based on the automobile production start-stop line according to claim 2 is characterized in that: The control module includes a limiter control submodule and a motor control submodule; The stopper control submodule is connected to the stopper; the stopper corresponds to the post one by one and is used to release the vehicle corresponding to the post; The stopper control submodule controls the stopper action according to production needs, and generates the sensor information indicating whether to release the vehicle at the current position; The motor control submodule is connected to the motor on the production line, and controls the motor movement according to production needs, thereby driving the vehicle to enter the production line or move along the production line, and generating the sensor information representing the transfer of the vehicle.

5. The digital twin simulation system based on the automobile production start-stop line according to claim 4 is characterized in that: The motor control submodule is connected to the elevator motor and the post motor; the elevator motor is used to lift the vehicle to enter the production line; when the elevator motor is activated, the sensor information representing the new vehicle on the line is generated; the post motor is used to drive the vehicle along the production line to the next post, or leave the production line; when the post motor is activated, the sensor information representing the movement of the existing vehicles is generated.

6. The digital twin simulation system based on the automobile production start-stop line according to claim 1 is characterized in that: The Internet of Things system includes a data acquisition module, a data storage module, a data calculation module and a data communication module; The data acquisition module uses the data communication module to obtain the sensor information from the production control system and delivers it to the data calculation module; the data calculation module uses the data storage module to integrate the sensor information, generate the production line status information, and finally transmits the production line status information to the digital twin system through the data communication module.

7. The digital twin simulation system based on the automobile production start-stop line according to claim 1 is characterized in that: The digital twin system includes a data preprocessing module, a data calculation module, a queue data module, a drive logic module and an animation module; The data preprocessing module performs format conversion on the received production line status information and sends it to the data calculation module; the data calculation module generates production line event information based on the production line status information and sends it to the queue data module; The queue data module records the changes of the vehicles on and off the line, and uses the production line event information to update the virtual queue information; when the virtual queue information changes, the drive logic module is notified and the virtual queue information is sent to the drive logic module; The driving logic module maintains the virtual production line status. When receiving the virtual queue information, it updates the virtual production line status based on the virtual queue information and sends it to the animation module. The animation module updates the animation according to the virtual production line status, generates a visualized virtual production line and displays it.

8. A simulation method using the digital twin simulation system based on the automobile production start-stop line as claimed in claim 1, characterized in that: Contains steps: Step S10, initializing the production control system, the Internet of Things system and the digital twin system; in the queue data module in the digital twin system, establishing a virtual queue and initializing all cells in the virtual queue to be empty; Step S20, the production control system controls the vehicle to enter the production line; Step S30, the production control system collects and reports the sensor information to the Internet of Things system; Step S40, the IoT system converts the information into production line status information and sends it to the digital twin system; Step S50, the digital twin system determines whether there is a conflict based on the production line status information and the current virtual queue information; If a conflict occurs, the digital twin system issues an alarm to indicate a production line conflict, otherwise it goes to step S60; Step S60, the queue data module calculates new virtual queue information based on the production line status information; Step S70, when the virtual queue information changes, the digital twin system updates the virtual production line status; Step S80, the digital twin system updates the animation according to the state of the virtual production line and displays the virtual production line; Step S90, the vehicle completes the production process at the current position, and the production control system controls the vehicle to enter the next position; if no new vehicle enters the production line, jump to step S30; Otherwise, jump to step S20.

9. The simulation method based on the digital twin simulation system of the automobile production start-stop line according to claim 8 is characterized in that: In step S50, the step of determining the production line conflict includes the following sub-steps: Step S51, reading the release information and the vehicle transfer information in the production line status information, and if a new vehicle is online, marking the target unit as the first unit in the virtual queue; If it is a stock vehicle movement, marking the target cell as the cell corresponding to the next position of the vehicle; If the vehicle is located at the end unit in the virtual queue, it is determined that there is no conflict, and the process jumps to step S53; Step S52, reading the occupancy information in the production line status information, and if there is a vehicle occupying the target unit, determining that there is a conflict; Otherwise, it is determined that there is no conflict; Step S53, complete the conflict detection and report the determination result.

10. The simulation method based on the digital twin simulation system of the automobile production start-stop line according to claim 8, characterized in that: The step of calculating the new virtual queue information in step S60 includes the following sub-steps: Step S61, reading the release information and the vehicle transfer information in the production line status information, if a new vehicle is online, proceeding to step S62; If it is a stock vehicle movement, go to step S63; otherwise, jump to step S66; Step S62, fill the vehicle information corresponding to the new vehicle into the first unit of the virtual queue, and proceed to step S66; Step S63, if the cell at the end of the virtual queue is not empty, remove the vehicle information from the cell; Step S64, moving the vehicle information in each unit in the virtual queue to the next unit; Step S65, clearing the vehicle information in the first unit in the virtual queue; Step S66: Generate the virtual queue information based on the virtual queue.

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