An automated transfer system for charcoal lumps based on digital twins and its control method

Abstract

This invention provides an automated transfer system and control method for a charcoal block warehouse based on digital twins, relating to the field of aluminum electrolysis technology. The system's intelligent overhead crane control system supports three operating modes. It integrates with the warehouse's digital twin management system via a wireless network to achieve automated charcoal block entry, exit, palletizing, and loading / unloading. The warehouse's digital twin management system establishes a digital twin model of the materials through dynamic 3D scanning, supporting inventory management, task scheduling, self-learning optimization, and predictive early warning. A video monitoring system provides real-time assistance, a network ensures data transmission, a security system protects the overhead crane, an access control system controls access, and a centralized control room enables monitoring. Through digital integration, the system enhances automation, improves production and management efficiency, and reduces production risks.

Description

Technical Field

[0001] This invention relates to the field of aluminum electrolysis technology, and more specifically, to an automated transfer system for a carbon block library based on digital twins and its control method. Background Technology

[0002] The aluminum electrolysis industry is an important basic material production field in modern industry, mainly involving the electrolytic smelting process of aluminum. Among them, the anode carbon block is a key consumable material, which plays the role of conducting electricity and providing carbon source in the electrolytic cell. The carbon block warehouse is the core facility for storing and transferring carbon blocks, and is responsible for the full life cycle management from production to use.

[0003] The stacking crane is mainly responsible for picking up and stacking raw blocks after they are put into storage, feeding raw blocks onto the assembly chain, unassembling cooked blocks onto the assembly chain, feeding slotted blocks onto the slotted chain, feeding slotted blocks onto the assembly chain, picking up, inspecting, and cleaning raw and cooked blocks required for production within the workshop, and transferring raw and cooked blocks to other workshops.

[0004] Currently, stacking cranes are still operated manually. The storage, transfer, and distribution of carbon blocks in the warehouse are all done manually, which is inefficient, poses certain safety risks, and cannot meet the current requirements for efficient, energy-saving, and automated storage and transfer of large-scale anode carbon blocks. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing an automated transfer system for charcoal briquette storage based on digital twins and its control method, aiming to solve the problems of low efficiency and high safety risks in manual production and management.

[0006] To achieve the above objectives, the main technical solution adopted by the present invention is an automated transfer system for a charcoal block warehouse based on digital twins, including an intelligent overhead crane control system, a warehouse digital twin management system, an industrial wired and wireless network system, a video surveillance system, a security protection system, an access control system, and a centralized control room. The intelligent crane control system is used to realize three working modes of crane: automatic operation, remote control operation, and cab operation. It is integrated with the warehouse digital twin management system through a wireless network to realize the automatic storage, retrieval, stacking, and loading / unloading of charcoal blocks. The warehouse area digital twin management system is used for inventory management, task management, crane scheduling management, query report management, and alarm management. The video surveillance system collects video signals and transmits them to the central control room to provide video surveillance assistance for crane operations. The industrial wired and wireless network system is used to transmit video data and control signals; The safety protection system is used for the safety protection of the crane body, surrounding facilities and ground workers; The access control system is used to control personnel access to the unmanned overhead crane operating area; The central control room is used to monitor the operating status of the entire system, handle faults, and switch modes.

[0007] The three operating modes are prioritized from highest to lowest as follows: cab operation, remote control operation, and automatic operation. When any operating mode is involved in control, the operating mode with the highest priority takes precedence, and other operating modes become invalid. When a safety limit is reached or a fault occurs, all operating modes become invalid until the fault is eliminated.

[0008] The intelligent overhead crane control system includes a trolley positioning device, a clamp height positioning device, a leak detection device, a laser radar scanning device, a stacking overhead crane human-machine monitoring device, a remote control device, a carbon block cleaning and clamping task control box, and an automatic loading and unloading device. The crane positioning device uses a combination of a scale and a PLC to achieve Gray line detection with a resolution of 5 mm, which is used to control the position of the crane and has a positioning accuracy of less than 20 mm. The fixture height positioning device detects and provides feedback on changes in the height of the overhead crane fixture in real time through an absolute encoder, with a resolution of 8192 per revolution and an error of ±0.25 degrees. It supports Profibus-DP or SSI interfaces. The leak detection device is used to monitor the position status of carbon blocks in each gripper of the crane, and to stop the crane and issue an alarm signal when there is an abnormality. The lidar scanning device includes no fewer than two lidars for scanning carbon blocks, identifying abnormal carbon blocks, and extracting size and location information. The human-machine monitoring device of the stacking crane is installed in the cab and is used to monitor and display the operating status of the equipment; The remote control device is used for emergency or temporary operation and supports functions consistent with those in the driver's cab. The charcoal block cleaning and clamping task control box is used to execute the charcoal block clamping command after cleaning, supports adding new signals to the central control room to realize remote control, and is equipped with a local remote switching switch. The automated loading and unloading device combines lidar with a binocular industrial camera to identify the position of the truck bed and the parallelism of the charcoal blocks, and automatically completes the loading and unloading operations.

[0009] The warehouse digital twin management system uses a combination of machine vision and lidar to perform dynamic 3D scanning, establishes a digital twin model of the warehouse materials, achieves accurate modeling of the warehouse materials, obtains the real-time status, location, height and width of the char blocks in the warehouse, and obtains the stacking status of char blocks and the total warehouse capacity through system analysis. It supports self-learning inventory allocation strategies and big data analysis for dynamic adjustment of zones, realizing real-time monitoring, problem prediction and early warning and intelligent management.

[0010] The video surveillance system includes vehicle-mounted cameras, ground cameras, video switches, hard disk recorders, and monitors; Each crane is equipped with no fewer than four onboard cameras with an IP66 or higher protection rating, supporting supplementary lighting, strong light suppression, and electronic image stabilization; the video data storage time is no less than 15 days, using hardware decoding, supporting 4K ultra-high-definition images and latency of less than 280ms.

[0011] The industrial wired and wireless network system includes an image transmission wireless network and a control signal wireless network; The onboard video signal is transmitted to the central control room via an image transmission wireless network; the onboard PLC and the control room PLC communicate via a control signal wireless network to enable operation, status display, and safety protection communication between the crane and the central control room.

[0012] The safety protection system includes a CDS independent operation monitoring device for real-time coordinate verification, which blocks control signals and disconnects the main power supply when the crane position deviates, and supports optical anti-collision technology and virtual operation area division.

[0013] The access control and protection system includes a passage door, an entrance host, and an indoor host. It supports remote intercom, video monitoring, and voice alarm. When unauthorized personnel enter, the system locks the door via a camera and issues a voice alarm, causing the overhead crane to slow down or stop until the personnel leave and then resume operation.

[0014] The centralized control room includes monitoring displays, video servers, PLC substations, system servers, switches, UPS, and industrial control computers. It is configured with primary and backup redundant servers, Windows operating system, and DB2 database, and supports UPS power supply. Each console is equipped with an emergency stop button and a PLC with PN communication mode, and a reserved network port for data reading and upgrades.

[0015] A control method for an automated charcoal block storage transfer system based on digital twins includes the following steps: S1: Dynamically scan the warehouse area using the warehouse area digital twin management system to establish a three-dimensional model of the charcoal block warehouse, and analyze inventory allocation through a self-learning strategy; S2: The digital twin management system of the reservoir area generates task instructions based on the scanning results and issues them to the intelligent overhead crane control system; S3: After receiving the task instruction, the intelligent overhead crane control system uses the automatic operation mode among the three working modes to automatically store, retrieve, stack, or load and unload charcoal blocks. During the execution process, the system monitors the position status of charcoal blocks in each gripper through a leakage detection device and stops and alarms when abnormalities occur.

[0016] The present invention has the following beneficial effects and advantages: 1. By using the scheduling information of the digital twin management system for the storage area, the system can automatically perform functions such as automatic storage, automatic retrieval, stacking, and loading and unloading of charcoal blocks, reducing manual intervention, significantly shortening the operation cycle, and improving the overall transfer efficiency.

[0017] 2. By establishing a digital twin model of materials through dynamic 3D scanning, it supports real-time inventory monitoring, intelligent task scheduling, self-learning optimization, and big data analysis, realizing unmanned management of the warehouse area. In the centralized control room, the production situation can be monitored in real time through video surveillance and 3D modeling, optimizing resource allocation and reducing management costs.

[0018] 3. Through multiple safety mechanisms such as safety protection systems, access control systems, leakage monitoring, and overload protection, the system effectively prevents crane collisions, personnel intrusions, and equipment failures, ensuring operator safety and reducing the probability of accidents. Attached Figure Description

[0019] Figure 1 This is a network configuration diagram of an automated transfer system for charcoal slab storage. Figure 2 This is a network topology diagram of an automated transfer system for charcoal blocks. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0021] like Figures 1-2 As shown, the automated transfer system for charcoal lumps based on digital twins includes an intelligent overhead crane control system, a digital twin management system for the storage area, an industrial wired and wireless network system, a video surveillance system, a security protection system, an access control system, and a centralized control room.

[0022] The intelligent overhead crane control system has undergone intelligent software and hardware upgrades and program development to achieve automatic crane operation, execute scheduling information from the warehouse digital twin management system, and realize automatic operation functions such as automatic warehousing and automatic retrieval of carbon blocks. It also adds wireless remote control operation functionality, allowing manual control of functions such as trolley movement, anode lifting, and electric hoist lifting. Meanwhile, the original cab operation functions are retained. The priority of the three operating modes, from highest to lowest, is cab operation, remote control operation, and automatic operation. When any operating mode is involved in control, the highest priority mode takes precedence, and other operating modes are disabled. When a safety limit is reached or a fault occurs, all operating modes are disabled until the fault is cleared.

[0023] The intelligent overhead crane control system and the warehouse digital twin management system communicate wirelessly, forming a wireless local area network to ensure real-time data exchange. The remote control function is identical to the manual operation function from the driver's cab. Furthermore, the system has reserved interlocking terminals for upstream and downstream equipment such as the grooving machine conveyor chain, enabling fully automated transfer of carbon blocks.

[0024] The trolley positioning device is used to control the position of the overhead crane trolley, with a positioning accuracy of less than 20 mm. The device employs scale-based positioning technology, detecting the horizontal movement signal of the crane via a scale mounted on the crane. The detected address is transmitted to the onboard PLC, which dynamically adjusts the brake based on the current position, destination address, and reference crane position to achieve precise stopping. The Gray busbar detection address resolution is 5 mm, allowing for intermittent or continuous detection, suitable for detecting the mechanical displacement of trolleys on uneven tracks, and designed for high temperature resistance and dustproofing. Each crane's trolley positioning device is independent and must not be shared.

[0025] The clamp height positioning device uses an absolute encoder to detect and provide feedback on changes in the crane clamp height in real time, positioning any stack of charcoal blocks based on changes in the running and lifting positions. During automatic operation, the crane automatically moves to the target charcoal block stack position based on the target charcoal block stack position information received from the crane scheduling system in the central control room and the real-time position signal fed back by the encoder, with a position accuracy controlled within ±20mm. Technical parameters are as follows: interface supports Profibus-DP, Ethernet / IP, PN, or SSI; compatible with shaft diameters of 6mm-15mm; resolution 8192 pixels per revolution, maximum number of revolutions 8192; maximum permissible speed 3000 rpm; error ±0.25 degrees Celsius; operating temperature -20℃~+85℃; enclosure protection rating IEC60529, IP67.

[0026] The leakage detection device is required to detect the position and status of the carbon block held by each gripper. If an abnormality is detected, the device should stop and issue an alarm signal to remind the operator to check and maintain the gripper, so as to avoid chaos in the warehouse management system.

[0027] The lidar scanning device is equipped with no less than two lidars on each stacker crane to complete the precise scanning of the charcoal blocks, identify abnormal blocks, and extract information such as size and location.

[0028] The human-machine monitoring device of the stacking crane is installed in the cab to monitor and display the operating status of the equipment, providing a basis for maintenance personnel to troubleshoot.

[0029] Each crane is equipped with a full-function remote control for emergency or temporary operation, supporting functions consistent with those in the cab.

[0030] Currently, each overhead crane is equipped with a carbon block cleaning and clamping task control box, which is used to issue commands for clamping the carbon blocks after cleaning. This application upgrades the carbon block cleaning and clamping task control box by adding a signal to the central control room to meet the requirements of remote control from the central control room. At the same time, a local remote transfer switch is installed on the surface of the carbon block cleaning and clamping task control box to retain the on-site operation and maintenance functions.

[0031] The automated loading and unloading system uses a combination of LiDAR and industrial cameras. The LiDAR and camera are both mounted in the middle of the overhead crane beam, using a binocular camera. Clear markings are painted at the loading and unloading positions for truck drivers to reference when parking. Before the truck enters the parking space, the overhead crane waits nearby. Once the truck driver parks the truck, the camera and LiDAR scan the truck and the charcoal blocks, identifying the position of the truck bed and the parallelism of the row of charcoal blocks relative to the clamps. If the system meets the requirements for full automation, the parking process ends; otherwise, the driver is prompted to move out of the parking space, adjust the truck's direction, and re-enter the parking space until the vehicle position or the parallelism of the entire row of charcoal blocks meets the requirements. The truck driver then leaves the truck and enters a safe area, pressing the "Load / Unload Available" confirmation button at the designated location. The overhead crane then automatically loads or unloads the truck.

[0032] The warehouse digital twin management system operates within a computer network and database environment. With integration technology at its core, it manages crucial information such as warehouse location, inventory, and inbound / outbound data for charcoal blocks, as well as the scheduling, management, and monitoring of transfers between the charcoal block warehouse and conveyor lines. Through a combination of machine vision and LiDAR, dynamic 3D scanning enables precise modeling of materials in the warehouse, obtaining real-time status, location, height, and width of charcoal blocks. System analysis reveals the stacking status of charcoal blocks and the total warehouse capacity, enabling real-time monitoring and intelligent management. The system possesses the following characteristics: high-fidelity 3D digital mapping of the actual scene; a visual and interactive interface for more intuitive display of inventory-related data; realization of the entire lifecycle operation process of the overhead crane and warehouse area; immersive 3D user interaction for the overhead crane and warehouse area; and real-time collection of various data during the warehousing process, predicting and issuing early warnings for potential problems.

[0033] The management system includes functions such as inventory management (block loading, palletizing, and unloading information), task management (task generation, modification, and reception), overhead crane scheduling management (overhead crane position tracking and automatic crane optimization), query and report management, alarm management, and video management. The warehouse digital twin management system is primarily used for the management, tracking, and recording of the entire lifecycle of charcoal blocks, from warehousing to palletizing and outbound. Through close integration with the overhead crane scheduling and control system and the production line control system, the system ensures the consistency and real-time nature of information flow and physical flow. It features: customizable classification and querying of inbound and outbound data; customizable inbound and outbound optimization strategies; support for self-learning inventory allocation strategies; and support for linked queries of overhead crane operation, fault logs, video, and inventory data. Each warehouse area is partitioned, and the partition name and size can be set in the software. The system has big data analysis capabilities; after running for a period of time, the system makes reasonable judgments on the partition size, resets the partition size, and records logs. The warehouse digital twin management system mainly includes task management, inbound management, outbound management, palletizing management, unloading management, plan change management, and manual intervention information management.

[0034] In terms of system maintenance, the first step is to initialize various charcoal block information and equipment information. Secondly, data backup and recovery are performed: this includes backing up and restoring recorded material information, equipment information, and data generated during task execution. Next, basic data management is implemented, including the management of various charcoal block information, automated storage and retrieval system (AS / RS) information, and equipment information. The warehouse model includes basic settings such as area division, location coding, supported charcoal block types, stacking layers, and single-row quantity. Equipment information includes equipment type, equipment code, crane span, rated lifting capacity, and chain plate position. Then, material storage period settings are implemented: storage periods for charcoal blocks are set according to their specific needs. Next, priority settings for inbound and outbound optimization rules are established: based on the storage characteristics of the charcoal block warehouse, optimization rules for inbound and outbound operations are formulated to achieve efficient storage and retrieval of the charcoal block warehouse. Finally, system user and operation permission management is implemented: role-based permission management, with different roles having different operation permissions, uniformly assigned by the administrator.

[0035] The overhead crane scheduling management system automatically assigns tasks to the overhead cranes to retrieve and store charcoal blocks from the charcoal block warehouse based on demand. It organizes the business processes involving the intelligent overhead cranes and the charcoal block warehouse into pending tasks in a workflow model, managing them uniformly according to the processing flow. The overhead crane scheduling system is the intelligent management system for the charcoal block transfer station, and should achieve intelligent and automated operation of the overhead cranes. The overhead crane scheduling system should include: signal acquisition (overhead cranes and ground equipment), information feedback, calculation methods, warehouse data retrieval, automatic / manual switching, and early warning alarms. Signal acquisition (overhead cranes, ground equipment, and manual operation): Provides the types of signals acquired. Information feedback: Provides the types of signals acquired. Calculation methods: Includes work priority, area priority, overhead crane priority, stacking principles, and handling of unknown situations. Warehouse data retrieval: The warehouse management system stores the charcoal block storage information for the entire charcoal block transfer station. The overhead crane scheduling system retrieves this data and combines it with the calculation methods to provide a reasonable scheduling plan. Automatic / Manual Switching: This function switches to manual mode for special operations that cannot be completed automatically (loading, scrap removal, etc.), allowing manual intervention to complete the task. Early Warning and Alarm: Provides pre-alarm measures and explanations to facilitate management and supervision of operators.

[0036] Warehouse management includes the management of charcoal block inbound and outbound operations, as well as handling of abnormal processes. It manages inbound and outbound task execution information, allocates storage locations, updates task status in real time, allows viewing task execution status, and performs operations such as pausing, terminating, and manually reporting completion. It also allows for the manual issuance of inbound and outbound tasks.

[0037] The inventory management function manages the inventory and related information in the charcoal block warehouse. It updates the quantity of various charcoal blocks in real time according to production requirements to avoid inventory imbalance. It displays the real-time inventory status and warehouse status, and can graphically display the storage area status. It also allows querying and modifying the storage status and operating status of the storage area.

[0038] Task management is used to decompose, schedule, and optimize tasks, monitor the status and control the actions of actuators, transmit work orders to the control system, and then to equipment such as overhead cranes, to control each actuator.

[0039] The query and report management system stores information on the receipt, issuance, and inventory of charcoal blocks. Users can query data through the query function and the system automatically generates reports for shifts, days, weeks, months, quarters, and years, which can be printed automatically.

[0040] Alarm management involves classifying and managing equipment alarms, system alarms, and other information, determining trigger priorities according to severity to ensure safety, and storing alarm logs in a categorized manner for easy retrieval.

[0041] The video surveillance system collects video signals using fixed high-definition cameras at key operational locations. These signals are then aggregated and sent to the video system cabinet in the electrical room of the control room. The video signals are transmitted via fiber optic cables and wireless access points (APs) and displayed on a monitoring screen in the central control room. The system primarily consists of front-end cameras, transmission, and control management components, including ground-based and vehicle-mounted video. Each overhead crane is equipped with at least four vehicle-mounted cameras, along with video switches and wireless video transmitters. Wireless video receivers are installed at the ends of the crane tracks, transmitting the video signals to the central control room via fiber optic cables. Several ground-based cameras are installed per span, with video signals centralized at a ground-based video control box and ultimately transmitted to the central control room via fiber optic cables. The specific number of ground-based cameras is adjusted based on actual site conditions. Network cameras should be suitable for 24-hour operation, with an IP66 or higher protection rating, and features such as supplemental lighting, strong light suppression, and electronic image stabilization. The number, specifications, and installation locations of the cameras must meet the needs of operational and on-site monitoring, providing a strong sense of three-dimensional space in the video image. The video surveillance system must ensure a sufficient monitoring angle and eliminate blind spots that could affect normal operations and safety. The cameras should be installed at a reasonable angle to prevent significant visual distortion for remote operators due to excessive tilt angles. Video surveillance should include operation monitoring, equipment monitoring, and security monitoring. A video recorder should be installed on the control panel in the central control room, with video data storage time no less than 15 days. The backend decoding equipment uses hardware decoding, with a total video system latency of less than 280ms, and possesses powerful backend management functions. It integrates image processing, network functions, screen management, and equipment maintenance. Each control panel is equipped with a 55-inch video monitor, providing excellent image quality and ultra-high-definition resolution. The entire system uses 4K technology, 2 megapixels, and ultra-high-definition image display. Screen configuration and image settings must consider the actual needs of remote operators, minimizing the number of video feeds while ensuring no blind spots, thus meeting the visual comfort of remote operators and reducing the difficulty of operation. The video switch provides 16 gigabit network access points, uploading network data to the center through an aggregation layer switch. This switch is highly reliable, easy to install and maintain, has fast switching capabilities, multiple access ports, and is suitable for small-scale LAN device access. One hard disk recorder corresponds to one video monitor. With secondary software development, when the overhead crane is operated, the monitor displays the corresponding video signal of the overhead crane.

[0042] The industrial wired and wireless network system utilizes a series of highly reliable, durable, and secure industrial wireless communication products. Designed with real-time performance, reliability, durability, and anti-interference as its core principles, it constructs a wireless network that meets the requirements for control data and video data transmission, considering equipment selection and technology choice. The operating frequency bands selected for wireless devices must not interfere with other networks within the storage area. Wireless bridges are strategically placed to ensure full signal coverage throughout the storage area. The system is divided into an image transmission wireless network and a control signal wireless network. Onboard video signals are transmitted to the control room via the image transmission wireless network. Onboard cameras converge to an onboard video switch, which connects to the onboard video wireless bridge. A ground-based video wireless bridge is installed at the end of the crane track, converging signals via fiber optic cable to the control room video switch. Signal exchange between the onboard PLC and the control room PLC is achieved through the control signal wireless network, enabling communication between the crane and the control room for operation, status display, and safety protection. Control signal wireless AP clients are installed at the crane end beams, transmitting onboard PLC signals to the onboard control signal wireless bridge via the switch. Ground-based control signal wireless AP users are installed at the end of the crane track, communicating with the control room PLC and switch via fiber optic cable. The image wireless network and the control wireless network are independent and must not interfere with each other. The control signal wireless network supports a high-power, high-bandwidth, high-performance 5.8GHz industrial-grade integrated antenna wireless bridge based on the 802.11a / n standard. The radio frequency section of this device is based on MIMO (Multiple-Input Multiple-Output) technology and adopts a 2T2R architecture, supporting a wireless bandwidth of 20 / 40MHz and a physical layer bandwidth of 300Mbps. The device has a maximum transmit power of 400mW, a receive sensitivity of up to -96dBm, a built-in 18dBi directional dual-polarized antenna, a maximum bridging distance of 1~5 kilometers, and a 100M Ethernet port design, with a maximum actual throughput of over 90Mbps. The wireless device features a CPU with a clock speed of up to 600MHz and 64MB of memory. It adopts advanced industrial-grade wireless base station design concepts, including surge and electrostatic protection (in 24V POE and DC power supply modes), voltage / temperature sensing, RF shielding, electromagnetic shielding, and a breathable housing. It has strong anti-interference capabilities and excellent protection performance, supports IP68 protection rating, and can operate in high and low temperatures of -40~75℃, meeting the requirements for uninterrupted operation in complex electromagnetic environments and harsh weather conditions.

[0043] The safety protection system is used to protect the crane itself, surrounding facilities, and ground workers. It includes a standalone CDS (Crane Defense System) monitoring device for real-time coordinate verification. This device blocks control signals and disconnects the main power supply when the crane deviates from its position. It also supports optical collision avoidance technology and virtual work area delineation. The safety protection system consists of three parts: safety protection for the crane itself; safety protection for surrounding facilities; and safety protection for ground workers.

[0044] The safety protection of the crane itself includes basic status detection, functional protection and operational safety, as well as the CDS safety protection system.

[0045] Basic condition monitoring, functional protection, and operational safety have the following functions: (1) Short circuit protection: An automatic air switch is installed in the main power circuit as short circuit protection for the main circuit of the crane, and a small-capacity automatic air switch is installed in the control circuit as short circuit protection for the control circuit. (2) Undervoltage protection: In the power distribution protection cabinet, the main contactor of the line is used as an undervoltage protection device. When the power supply is interrupted, the power supply is automatically disconnected. (3) Zero position protection: When operating in the cab, when the crane starts and when the power supply is restored after undervoltage, all controller handles must be placed in the zero position before the motors of each mechanism can be started. (4) Travel limit protection: The crane's large and small trolley running mechanisms are equipped with limit switches at both ends of the end beam and the trolley track as travel limit protection. (5) Lifting limit protection: The hoisting mechanism is equipped with double lifting limit switches, which can ensure that when the hook reaches the limit position, the power supply of the lifting circuit or the main power supply can be automatically cut off. (6) Emergency power failure protection: An emergency switch is installed in the control circuit of the crane. When an accident or emergency occurs, the power supply of the control circuit can be cut off at any time, thereby cutting off the power supply of the main circuit and ensuring the safety of the crane. (7) Safety switch setting for railing doors: Safety switches are installed on the doors leading to the crane and the inclined ladder doors of the bridge frame. When any of the doors is opened, the safety switch is disconnected, causing the main contactor to automatically disconnect and all mechanisms of the crane to stop working. (8) Overload protection: A load limiter (overload limiter) is installed on the hoisting mechanism. When the load reaches 90% of the rated lifting capacity, an audible and visual alarm is triggered; when it reaches 105%, the power supply to the ascending circuit is disconnected, and only descending operation is allowed. (9) Emergency stop function: Emergency stop buttons are installed on the door of the onboard electrical control cabinet, the ground operation button box, and the ground centralized control room. In case of a fault, an emergency stop can be performed at any location. When the emergency stop button is operated, the main power supply of the crane is cut off, the power supply of the speed regulating device is also cut off, and the working brake is immediately closed. (10) Clamp carbon block detection system monitors in real time whether there are any issues such as sliders or blocks falling during the clamping process. (11) Central control system monitors the wireless communication status in real time. Once a communication failure occurs, the system alarm is triggered.

[0046] The CDS safety protection system has the following functions: Based on past production processes where personnel could promptly take corresponding emergency measures when crane malfunctioned, the crane operation has been converted to unmanned operation, leaving operators far from the crane and facing situations where timely takeover and control are impossible. Therefore, this project requires a dedicated safety protection system for the crane. When abnormal crane operation is detected, the system can promptly implement protective measures to ensure production safety from the outset. The CDS safety protection system, as an independent operation monitoring system, is unaffected by WSPC. Control commands can only be received and executed by the crane after coordinate verification. If the crane's operating position deviates from its coordinate position due to brake pad aging, malfunction, actuator contactor abnormalities, or other factors, the CDS can quickly block control signals and disconnect the crane's main power supply based on the fault type to ensure the crane operates safely on the prescribed trajectory.

[0047] In addition to ensuring the safety of cranes operating between themselves and with other cranes, it is also necessary to consider the safety of cranes in relation to surrounding facilities during operation. Based on the measurement data of the crane's three axle positions, a virtual three-dimensional working area is delineated to ensure that the cranes do not collide with surrounding fixed facilities during operation, thereby improving crane safety. Obstacle coordinates are defined based on the actual location on site, a safe crane path is calculated, and the optimal crane trajectory is automatically calculated based on the time scheduling start point information. This enables automatic obstacle avoidance and shortest distance selection, achieving safe and efficient automated crane operation. Collision avoidance is a crucial function of unmanned cranes. The collision avoidance system must operate independently of the crane's other control systems. This ensures that even if the PLC system or positioning equipment malfunctions, the collision avoidance system can still function normally, preventing collisions between cranes. The crane employs optical (grating or laser) collision avoidance technology. A grating or laser collision avoidance system consists of a grating emitter installed on one crane and a reflector installed on an adjacent crane. The grating emitter is adjusted to a specific angle with the crane track. When the distance between two overhead cranes gets close enough, the light emitted by the grating will hit the reflector of the adjacent crane. Upon receiving the reflected signal, the system will issue an alarm signal.

[0048] The truck unloading station is equipped with a vehicle identification system. During unloading operations, the system automatically detects and determines the position of vehicles and personnel, and automatically plans a safety red zone based on the determination results. The overhead crane is prohibited from operating in this area. If it must pass through, it must be raised to the upper stop position to pass through, ensuring the safety of vehicles and personnel.

[0049] The access control system demarcates unmanned overhead crane operating areas (areas where personnel are prohibited) within the warehouse area based on production needs. This includes protective railings, access doors with electromagnetic locks, a door station (equipped with a camera and remote intercom), and an indoor station (equipped with a display screen and remote intercom). When personnel need to enter the overhead crane operating area, they submit an application to the on-duty personnel in the central control room via the door station. The on-duty personnel can see and communicate with the personnel entering through the indoor station; after approval, the electromagnetic lock is remotely opened to unlock the door. The same procedure applies when personnel leave the operating area. If unauthorized personnel enter the work area, the camera will lock and issue a voice alarm on-site, and a high-frequency alarm will sound in the central control room. The overhead crane will slow down or stop until personnel are away, and operations will resume after the on-site alarm and the central control room alarm are cleared.

[0050] The central control room is equipped with monitoring displays, video servers, clients, main control PLC substations, system servers, switches, UPS, industrial control computers, video monitoring storage devices and other necessary equipment. The main functions include monitoring the normality and corresponding strategies of the overhead crane, transport chain and vehicle logistics flow; monitoring the position of the overhead crane and whether the work order is executed normally; basic handling of overhead crane failure and emergency alarm and reset in case of major failure, with accurate and complete information; automatic or manual switching to other modes and alarm when the unmanned overhead crane work order cannot be executed and emergency handling is required; basic measures and major fault alarm and reset when other ground systems (vehicle positioning, wireless network, CCTV, etc.) are abnormal; monitoring and confirmation of the safety system. (1) Control console: One overhead crane remote control console with three workstations is configured in the central control room. An emergency stop button is provided on the control console. (2) Control console PLC: The control console is equipped with a PLC with superior CPU performance. After collecting the control signals of the control console, it is connected to the wireless transmitter installed outside the control room through PN communication. The console PLC is supplied as a set with the console. Each console PLC has a reserved network port for users to read data and upgrade the system later. (3) Central control room server: Each system host uses 2 servers with a primary and backup (cold backup) redundancy design. It is equipped with 1 server rack, Windows operating system, 1 DB2 database, and several aggregation switches and edge switches. At the same time, the system is equipped with 1 UPS power distribution cabinet to power the host system and the ground PLC system. (4) Client: Each crane is equipped with a client with two 32-inch 4K displays to monitor the operation status of the entire system.

[0051] The control method for an automated charcoal block storage transfer system based on digital twins includes the following steps: S1: The warehouse area is dynamically 3D scanned using a digital twin management system to establish a 3D model of the charcoal block warehouse, and inventory allocation is analyzed using a self-learning strategy. S2: The warehouse area digital twin management system generates task instructions based on the scan results and issues them to the intelligent overhead crane control system. S3: After receiving the task instructions, the intelligent overhead crane control system uses the automatic operation mode from the three working modes to automatically store, retrieve, stack, or load / unload charcoal blocks. During execution, a leakage detection device monitors the position and status of charcoal blocks in each gripper, and stops and alarms when abnormalities occur. In actual implementation, the control method further integrates the various modules of the system: In S1, a combination of machine vision and LiDAR is used for scanning to establish a digital twin model, supporting real-time status updates and predictive warnings; in S2, task instructions are generated based on inventory management, overhead crane scheduling, and big data analysis to ensure optimized allocation; in S3, the execution process is assisted by video monitoring and supervised by a safety protection system, and data is transmitted through an industrial network. If an abnormality occurs, the working mode is switched and an alarm is handled until normal operation is restored.

[0052] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. An automated transfer system for charcoal briquette storage based on digital twins, characterized in that, This includes an intelligent overhead crane control system, a warehouse area digital twin management system, an industrial wired and wireless network system, a video surveillance system, a security protection system, an access control system, and a centralized control room; The intelligent crane control system is used to realize three working modes of crane: automatic operation, remote control operation, and cab operation. It is integrated with the warehouse digital twin management system through a wireless network to realize the automatic storage, retrieval, stacking, and loading / unloading of charcoal blocks. The warehouse area digital twin management system is used for inventory management, task management, crane scheduling management, query report management, and alarm management. The video surveillance system collects video signals and transmits them to the central control room to provide video surveillance assistance for crane operations. The industrial wired and wireless network system is used to transmit video data and control signals; The safety protection system is used for the safety protection of the crane body, surrounding facilities and ground workers; The access control system is used to control personnel access to the unmanned overhead crane operating area; The central control room is used to monitor the operating status of the entire system, handle faults, and switch modes.

2. The automated transfer system for a charcoal block warehouse based on digital twins according to claim 1, characterized in that, The three operating modes are prioritized from highest to lowest as follows: cab operation, remote control operation, and automatic operation. When any operating mode is involved in control, the operating mode with the highest priority takes precedence, and other operating modes become invalid. When a safety limit is reached or a fault occurs, all operating modes become invalid until the fault is eliminated.

3. The automated transfer system for charcoal briquette storage based on digital twins according to claim 1, characterized in that, The intelligent overhead crane control system includes a trolley positioning device, a clamp height positioning device, a leak detection device, a laser radar scanning device, a stacking overhead crane human-machine monitoring device, a remote control device, a carbon block cleaning and clamping task control box, and an automatic loading and unloading device. The crane positioning device uses a combination of a scale and a PLC to achieve Gray line detection with a resolution of 5 mm, which is used to control the position of the crane and has a positioning accuracy of less than 20 mm. The fixture height positioning device detects and provides feedback on changes in the height of the overhead crane fixture in real time through an absolute encoder, with a resolution of 8192 per revolution and an error of ±0.25 degrees. It supports Profibus-DP or SSI interfaces. The leak detection device is used to monitor the position status of carbon blocks in each gripper of the crane, and to stop the crane and issue an alarm signal when there is an abnormality. The lidar scanning device includes no fewer than two lidars for scanning carbon blocks, identifying abnormal carbon blocks, and extracting size and location information. The human-machine monitoring device of the stacking crane is installed in the cab and is used to monitor and display the operating status of the equipment; The remote control device is used for emergency or temporary operation and supports functions consistent with those in the driver's cab. The charcoal block cleaning and clamping task control box is used to execute the charcoal block clamping command after cleaning, supports adding new signals to the central control room to realize remote control, and is equipped with a local remote switching switch. The automated loading and unloading device combines lidar with a binocular industrial camera to identify the position of the truck bed and the parallelism of the charcoal blocks, and automatically completes the loading and unloading operations.

4. The automated transfer system for a charcoal block warehouse based on digital twins according to claim 1, characterized in that, The warehouse digital twin management system uses a combination of machine vision and lidar to perform dynamic 3D scanning, establishes a digital twin model of the warehouse materials, achieves accurate modeling of the warehouse materials, obtains the real-time status, location, height and width of the char blocks in the warehouse, and obtains the stacking status of char blocks and the total warehouse capacity through system analysis. It supports self-learning inventory allocation strategies and big data analysis for dynamic adjustment of zones, realizing real-time monitoring, problem prediction and early warning and intelligent management.

5. The automated transfer system for a charcoal block warehouse based on digital twins according to claim 1, characterized in that, The video surveillance system includes vehicle-mounted cameras, ground cameras, video switches, hard disk recorders, and monitors; Each crane is equipped with no fewer than four onboard cameras with an IP66 or higher protection rating, supporting supplementary lighting, strong light suppression, and electronic image stabilization; the video data storage time is no less than 15 days, using hardware decoding, supporting 4K ultra-high-definition images and latency of less than 280ms.

6. The automated transfer system for a charcoal block warehouse based on digital twins according to claim 1, characterized in that, The industrial wired and wireless network system includes an image transmission wireless network and a control signal wireless network; The onboard video signal is transmitted to the central control room via an image transmission wireless network; the onboard PLC and the control room PLC communicate via a control signal wireless network to enable operation, status display, and safety protection communication between the crane and the central control room.

7. The automated transfer system for a charcoal block warehouse based on digital twins according to claim 1, characterized in that, The safety protection system includes a CDS independent operation monitoring device for real-time coordinate verification, which blocks control signals and disconnects the main power supply when the crane position deviates, and supports optical anti-collision technology and virtual operation area division.

8. The automated transfer system for a charcoal block warehouse based on digital twins according to claim 1, characterized in that, The access control and protection system includes a passage door, an entrance host, and an indoor host. It supports remote intercom, video monitoring, and voice alarm. When unauthorized personnel enter, the system locks the door via a camera and issues a voice alarm, causing the overhead crane to slow down or stop until the personnel leave and then resume operation.

9. The automated transfer system for a charcoal block warehouse based on digital twins according to claim 1, characterized in that, The centralized control room includes monitoring displays, video servers, PLC substations, system servers, switches, UPS, and industrial control computers. It is configured with primary and backup redundant servers, Windows operating system, and DB2 database, and supports UPS power supply. Each console is equipped with an emergency stop button and a PLC with PN communication mode, and a reserved network port for data reading and upgrades.

10. A control method for an automated transfer system of a charcoal block warehouse based on digital twins, characterized in that, Includes the following steps: S1: Dynamically scan the warehouse area using the warehouse area digital twin management system to establish a three-dimensional model of the charcoal block warehouse, and analyze inventory allocation through a self-learning strategy; S2: The digital twin management system of the reservoir area generates task instructions based on the scanning results and issues them to the intelligent overhead crane control system; S3: After receiving the task instruction, the intelligent overhead crane control system uses the automatic operation mode among the three working modes to automatically store, retrieve, stack, or load and unload charcoal blocks. During the execution process, the system monitors the position status of charcoal blocks in each gripper through a leakage detection device and stops and alarms when abnormalities occur.

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