Automatic unloading and transfer method for polyester PET film rolls

Abstract

The present invention discloses a method for automatically unloading and transferring polyester (PET) film rolls, which relates to the technical field of polyester film roll production automation. The method comprises the following steps: S1, using a truss robot to receive unloading instructions from a production management system. After a roll of polyester (PET) film roll is produced by a laminating machine, the truss robot removes the roll from a rewinding station and places it on a dedicated tray equipped with a positioning and limiting structure; S2, when the truss robot completes the unloading action, the unloading control system generates an unloading completion signal, which is sent to the AGV scheduling system via an intermediate communication interface. The present invention achieves highly reliable synchronous control between the truss robot and the AGV system, ensuring closed-loop execution of tasks; has anomaly detection and task rollback mechanisms, improving system fault tolerance and continuous operation capabilities; introduces dynamic scheduling and prediction algorithms, optimizes AGV resource allocation and path planning, and comprehensively improves production efficiency and system stability.

Description

Technical Field

[0001] The invention relates to the technical field of polyester film roll production automation, and in particular to a method for automatically unloading and transferring polyester PET film rolls. Background Art

[0002] "Automated unloading and reordering of polyester PET film rolls" refers to a complete intelligent process during the polyester PET film production process. Heavy film rolls, after production at the laminating machine, are unloaded from the machine using automated equipment (such as gantry robots) and then transferred and distributed according to a preset sequence, stacking method, and logistics path. This method combines specialized fixtures, pallet design, and an AGV forklift system to identify film rolls of different specifications, automatically unloading the rolls from the laminating machine, stably stacking them on the pallet, and accurately transferring them to subsequent aging or storage processes. This eliminates the inefficiencies and chaotic scheduling associated with traditional manual operations, ensuring efficient and orderly transitions between processes throughout the production line while also improving production line flexibility and automation.

[0003] The existing technology has the following deficiencies: In the process of automatic unloading and sequencing of polyester PET film rolls in the existing technology, there is a key control problem, namely the failure of instruction synchronization between the truss robot unloading control system and the AGV scheduling system. This problem manifests itself at the control level as time delays or data loss in the task scheduling logic, resulting in the AGV failing to take over the pallet transfer task in time after the robot completes the unloading operation, causing pallet accumulation at the unloading station, disrupting the production rhythm, and even causing equipment operation conflicts or collision accidents. This type of problem usually stems from network transmission delays, inconsistent scheduling logic, or abnormal intermediate communication interfaces, which have a very serious impact on continuously operating automated production lines and can easily cause systemic stagnation and production capacity loss. Therefore, building a highly reliable and real-time control coordination mechanism is a core technical challenge to ensure the stable operation of the automatic unloading and sequencing system.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for automatic unloading and sequencing of polyester PET film rolls, which realizes highly reliable synchronous control between the truss robot and the AGV system to ensure closed-loop execution of tasks; it has an anomaly detection and task rollback mechanism to improve the system's fault tolerance and continuous operation capabilities; it introduces dynamic scheduling and prediction algorithms to optimize AGV resource allocation and path planning, comprehensively improve production efficiency and system stability, and solve the problems in the above-mentioned background technology.

[0006] In order to achieve the above object, the present invention provides the following technical solution: a method for automatically unloading and transferring polyester PET film rolls, comprising the following steps:

[0007] S1: A truss robot receives unloading instructions from the production management system. After the laminating machine completes the production of a roll of polyester film, the truss robot removes the film roll from the winding station and places it on a dedicated tray with a positioning and limiting structure.

[0008] S2, when the truss robot completes the unloading action, the unloading control system generates an unloading completion signal, which is sent to the AGV scheduling system through the intermediate communication interface;

[0009] S3, after receiving the unloading completion signal, the AGV scheduling system calls the preset path rules and transfer priority strategy, selects the corresponding idle AGV forklift from the AGV task pool, and assigns it to perform the current transfer task;

[0010] S4: The AGV forklift follows the designated path navigation system to the unloading station, automatically identifies the pallet barcode, confirms the load information, and then loads the pallet and film roll onto the vehicle body;

[0011] In step S5, the AGV forklift accurately transports the film roll pallet to the designated curing furnace entrance or temporary buffer area according to the task instructions in the MES system. The task execution status is uploaded to the warehouse management system in real time.

[0012] S6: After the AGV completes the transfer task, the truss robot control system resets and enters the standby state. After receiving the instruction to unload the next film roll, it repeats S1 to S5 to ensure operation under closed-loop logic control and avoid scheduling conflicts.

[0013] Preferably, the truss robot adopts a three-axis linkage structure, corresponding to axis, Axis and Axis direction, and integrated with a set of variable position handling fixtures, the fixtures have dual functions: one is to hook the core shaft of the film roll through the rotating hook structure to achieve heavy-load lifting; the other is to grab the core shaft through the parallel clamping claw structure to complete the extraction and re-insertion action;

[0014] Whenever the robot performs the action before unloading, its control system automatically adjusts the distance between the clamps according to the film roll diameter and core shaft length data issued by MES to ensure handling stability and unloading accuracy.

[0015] Preferably, the tray is provided with a bidirectional limiting groove structure and an adjustable wedge-shaped limiting block, and each tray surface is preset with three symmetrically distributed limiting tracks for stacking three film rolls in a "pin" shape;

[0016] Each wedge-shaped limit block is connected to the track through a sliding buckle device, and the sliding distance is accurately marked by the coding ruler at the bottom of the tray;

[0017] When the truss robot performs the stacking action, the limit block displacement program is automatically called according to the film roll specifications, so that both ends of each film roll are stably supported by the limit blocks;

[0018] The limiting structure also has an anti-seismic cushion layer, which effectively absorbs the micro-vibration generated during transportation and prevents the film roll from shifting or overturning, thereby ensuring stacking safety and transportation stability.

[0019] Preferably, the control system is equipped with a multi-system synchronization control logic module, the core of which is the timestamp synchronization algorithm. Each unloading event will record the exact timestamp after the truss robot completes the last action node. , the response time of the AGV dispatching system after receiving the signal is recorded as ,like , If there is a time difference, the control system will trigger the synchronization exception handling mechanism, automatically start the backup AGV or resend the instruction to avoid task accumulation.

[0020] Preferably, in order to ensure the system scheduling stability and response time accuracy, a scheduling response correction mechanism based on PID+ prediction algorithm is added to the control system. The specific steps are as follows:

[0021] Set the target value of task signal delay , the current measured system delay is , define the error term, and the calculation expression is as follows: , where is the error term;

[0022] Set the scale factor , integral coefficient , differential coefficient , calculate the adjustment parameters, the calculation expression is as follows:

[0023] , where Is the proportional coefficient, which is used to determine the direct proportional relationship of the error term in the control output. is the integral coefficient, which is used to accumulate the trend of error over time and eliminate static error. Is the differential coefficient, which is sensitive to the rate of change of the error and is used to predict trends in advance. is the PID controller at time The regulation signal given, Is an imaginary time variable, representing the time from the start time 0 to the moment A scan variable of At every point in time The systematic error on is a tiny time increment;

[0024] The time series prediction model AR(1) is used to estimate the delay of the next cycle. The delay calculation formula is as follows: , where is the next cycle prediction delay, is the delayed autocorrelation coefficient, is the model offset correction;

[0025] Adjust the thread scheduling priority of the signal relay server. The formula is as follows:

[0026] , where It is a comprehensive indicator of scheduling priority;

[0027] when hour, It is a preset tolerance threshold that triggers the main control system to switch to the backup relay server to ensure the continuity of command transmission and real-time response.

[0028] Preferably, during the execution of the unloading and reordering task, the AGV scheduling priority is optimized in real time. The specific steps are as follows:

[0029] Assume the weight of the film roll is , the pallet weight is , calculate the total load, the calculation expression is as follows: , where is the total load weight;

[0030] The estimated time for film roll to be taken out of the oven is , the current time is , calculate the waiting time, the calculation expression is as follows: , where It’s waiting time;

[0031] Set the current position of each AGV , the target unloading point position is , calculate the Euclidean distance, the calculation expression is as follows:

[0032] , where and It is The current position coordinates of the AGV forklift, and is the coordinate of the target unloading point, It is The Euclidean distance between the AGV and the target point;

[0033] According to the remaining power of each AGV , speed coefficient , load factor , the scheduling priority score is obtained, and the calculation expression is as follows:

[0034] , where It is The scheduling priority score of each AGV, load factor, ;

[0035] Select the largest one among all idle AGVs The corresponding AGV performs the current task, and the remaining vehicles enter the waiting queue.

[0036] Preferably, the AGV forklift is equipped with a dual visual recognition system, including a QR code recognition module and a laser radar scanning module, for accurately locating the pallet position and driving path;

[0037] The QR code recognition system uses the on-board camera to scan the label on the bottom of the pallet to obtain the pallet number and material roll product information; the lidar module simultaneously scans the ground and obstacles to build a real-time environmental map;

[0038] The vision system communicates with the AGV dispatching platform in real time, transmitting position data via the UDP protocol and refreshing it every 5 milliseconds to ensure optimal path selection. It automatically avoids obstacles and dynamically replans the path during driving to ensure that the pallet accurately reaches the target location.

[0039] Preferably, when the AGV forklift is transferring the film roll pallet to the curing furnace or buffer area, a path planning algorithm based on the fusion of A-path search and dynamic window method is used to pre-generate the optimal path before executing the task, and to perceive the operating status of other AGVs and environmental obstacles in real time during the transfer process to achieve collision avoidance and path replanning;

[0040] During the route planning process, each driving route is equipped with a transfer segment number and a timestamp recording mechanism. The WMS system dynamically adjusts the target curing furnace entry point based on the film roll curing time window and the waste heat utilization rate in the furnace.

[0041] If the current target furnace area is temporarily full, the AGV is instructed to enter the intermediate buffer area first, temporarily store it according to the preset FIFO rules, and regularly rearrange the transfer queue to ensure smooth logistics of the entire production line and no conflicts in tasks.

[0042] Preferably, after completing the film roll transfer task, the AGV forklift automatically drives to the empty pallet recovery area and performs the following steps:

[0043] The pallet detection sensor identifies the stacking height of empty pallets. If the height exceeds the preset safety threshold, it automatically switches to the standby empty pallet stacking point;

[0044] Empty pallets are stacked to a standard height using a built-in lifting module, with no more than 6 layers per stack;

[0045] According to the instructions of the dispatching system, transport to the entrance of the disassembly machine.

[0046] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0047] The present invention achieves high real-time and low-latency communication between the truss robot unloading control system and the AGV scheduling system by constructing a unified central control synchronization mechanism or high-frequency signal bus, breaking through the bottleneck problems such as network delay and instruction drift commonly seen in existing multi-system collaboration. The signal after each unloading action is completed can be received and responded to immediately by the AGV system at the millisecond level, avoiding a series of chain reactions such as pallet accumulation, task misordering, and transfer delays, greatly improving the stability and synchronization accuracy of the entire production line. This beneficial effect ensures the logical closed-loop execution of the automated process and is the key foundation for opening up the full-process control chain of "unloading-transfer-maturation".

[0048] The present invention introduces task status feedback, anomaly detection, and scheduling rollback mechanisms, establishing a complete closed-loop control system. This system can immediately identify the source of problems when a task is interrupted, an instruction is lost, or AGV scheduling fails, and automatically call upon backup AGV resources to restart the task, or, if necessary, roll back to the previous successful node for rescheduling. This mechanism effectively avoids system paralysis and production stagnation caused by single-point failures, improving the robustness and stability of the entire system. In a continuous, high-paced production environment, this beneficial effect ensures seamless connectivity between devices, improving the overall operational efficiency and risk resistance of the entire line.

[0049] By introducing an AGV priority scoring model and a predictive control algorithm, this invention completes data collection, real-time calculation, and path planning before task scheduling. It effectively integrates multi-dimensional information such as film roll weight, transfer distance, vehicle status, and task timing, and combines historical task data to predict system latency trends, ensuring that each AGV call is based on optimal resource allocation. This strategy not only improves the efficiency of single-task execution but also avoids AGV resource idling, congestion, and scheduling conflicts, making the entire unloading and sequencing process more intelligent and adaptive. This beneficial effect significantly improves the flexible adjustment capability of the production rhythm and the comprehensive utilization rate of system resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction to the drawings required for use in the embodiments will be given below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0051] Figure 1 The present invention is a flowchart of the method for automatically unloading and transferring polyester PET film rolls. DETAILED DESCRIPTION

[0052] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art.

[0053] The present invention provides Figure 1 The method for automatically unloading and transferring polyester film rolls shown includes the following steps:

[0054] S1: A truss robot receives unloading instructions from the production management system. After the laminating machine completes the production of a roll of polyester film, the truss robot removes the film roll from the winding station and places it on a dedicated tray with a positioning and limiting structure.

[0055] The truss robot adopts a three-axis linkage structure, corresponding to Axis (transverse movement), Axis (longitudinal movement) and Axis (lifting) direction, and integrated with a set of variable position handling fixtures, the fixtures have dual functions: one is to hook the core shaft of the film roll through the rotating hook structure to achieve heavy-load lifting; the other is to grab the core shaft through the parallel clamping structure to complete the extraction and re-insertion action;

[0056] Whenever the robot performs the action before unloading, its control system automatically adjusts the distance between the clamps according to the film roll diameter and core shaft length data issued by MES to ensure handling stability and unloading accuracy.

[0057] To improve unloading efficiency, the truss robot is equipped with a state feedback module, which calibrates each action node through a position encoder and feeds it back to the main control system in real time to ensure that the AGV scheduling system can synchronously start subsequent processes.

[0058] The pallet is equipped with a two-way limiting groove structure and an adjustable wedge-shaped limiting block. Three symmetrically distributed limiting tracks are preset on the surface of each pallet for stacking three film rolls in a "pin" shape.

[0059] Each wedge-shaped limit block is connected to the track through a sliding buckle device, and the sliding distance is accurately marked by the coding ruler at the bottom of the tray;

[0060] When the truss robot performs the stacking action, the limit block displacement program is automatically called according to the film roll specifications, so that both ends of each film roll are stably supported by the limit blocks;

[0061] The limiting structure also has an anti-seismic cushion layer, which effectively absorbs the micro-vibration generated during transportation and prevents the film roll from shifting or overturning, thereby ensuring stacking safety and transportation stability.

[0062] S2, when the truss robot completes the unloading action, the unloading control system generates an unloading completion signal, which is sent to the AGV scheduling system through the intermediate communication interface;

[0063] The control system is equipped with a multi-system synchronous control logic module, the core of which is the timestamp synchronization algorithm. Each unloading event will record the precise timestamp after the truss robot completes the last action node. , the response time of the AGV dispatching system after receiving the signal is recorded as ,like If there is a time difference, the control system will trigger the synchronization exception handling mechanism, automatically start the backup AGV or resend the instruction to avoid task accumulation.

[0064] All timestamp information is recorded in the log for subsequent tracing and system optimization, fundamentally improving the stability and response consistency of the system.

[0065] By monitoring and judging Whether it exceeds , the system can automatically detect potential communication problems or control delays, and promptly start the backup instruction resending mechanism or standby AGV scheduling mechanism to ensure the real-time and reliability of the entire automated transfer process.

[0066] In order to ensure the system scheduling stability and response time accuracy, a scheduling response correction mechanism based on PID+ prediction algorithm is added to the control system. The specific steps are as follows:

[0067] Set the target value of task signal delay , the current measured system delay is , define the error term, and the calculation expression is as follows: , where is the error term, which represents the deviation between the current actual delay and the target delay. A positive value indicates that the delay is longer than expected, and a negative value indicates that the reaction is too fast (which can be used to judge overcompensation);

[0068] Set the scale factor , integral coefficient , differential coefficient , calculate the adjustment parameters, the calculation expression is as follows:

[0069] , where Is the proportional coefficient, which is used to determine the direct proportional relationship of the error term in the control output. is the integral coefficient, which is used to accumulate the trend of error over time and eliminate static error. Is the differential coefficient, which is sensitive to the rate of change of the error and is used to predict trends in advance. is the PID controller at time Given the adjustment signal, control the signal adjustment amount, comprehensively consider the current error, historical error accumulation and error change trend, Is an imaginary time variable, representing the time from the start time 0 to the moment A scan variable of At every point in time The systematic error on time At time , the difference between the system target value and the actual value, is a small time increment, which is a time variable An infinitesimal increment of , used to describe a very short period of time The tiny "area" accumulated;

[0070] The time series prediction model AR(1) is used to estimate the delay of the next cycle. The delay calculation formula is as follows: , where It is the predicted delay of the next cycle. Based on the historical delay sequence, it estimates the possible communication delay of the next task cycle. It is the autocorrelation coefficient of delay, which reflects the influence of current delay on future delay. When it is close to 1, the system inertia is large. The value range is 0-1. It is the model offset correction used to compensate for nonlinear errors, network fluctuations, system load, etc.

[0071] Adjust the thread scheduling priority of the signal relay server. The formula is as follows:

[0072] , where It is a comprehensive indicator of scheduling priority. The larger the value, the closer the current system state is to the ideal state.

[0073] when hour, It is a preset tolerance threshold that triggers the main control system to switch to the backup relay server to ensure the continuity of command transmission and real-time response.

[0074] S3, after receiving the unloading completion signal, the AGV scheduling system calls the preset path rules and transfer priority strategy, selects the corresponding idle AGV forklift from the AGV task pool, and assigns it to perform the current transfer task;

[0075] During the execution of the unloading and reordering task, the AGV scheduling priority is optimized in real time. The specific steps are as follows:

[0076] Assume the weight of the film roll is , the pallet weight is , calculate the total load, the calculation expression is as follows: , where is the total load weight, which is the total weight that the AGV needs to carry in the actual handling task;

[0077] The estimated time for film roll to be taken out of the oven is , the current time is , calculate the waiting time, the calculation expression is as follows: , where Is the waiting time, which indicates how much time is left between the current task and its ideal release time point. If A smaller value indicates that the task is more urgent and needs to be scheduled first. The remaining time between the task and its ideal release time is how much time is left.

[0078] Set the current position of each AGV , the target unloading point position is , calculate the Euclidean distance, the calculation expression is as follows:

[0079] , where and It is The current position coordinates of each AGV forklift indicate the absolute position of each AGV in the factory map. and is the target unloading point coordinate, indicating the location coordinate of the pallet where the current film roll is located. It is The Euclidean distance between an AGV and the target point represents the linear distance between the AGV and the target unloading point. The smaller the value, the closer the AGV is to the starting point of the task.

[0080] According to the remaining power of each AGV , speed coefficient , load factor , the scheduling priority score is obtained, and the calculation expression is as follows:

[0081] , where It is The scheduling priority score of each AGV. The larger the score, the higher the priority. The scheduling system will select the maximum The AGV performs the current transfer task, load factor, , which indicates the load ratio that can be supported by the unit remaining power. The higher the value, the worse the current power support capability is, and the scheduling priority should be lowered;

[0082] Select the largest one among all idle AGVs The corresponding AGV performs the current task, and the remaining vehicles enter the waiting queue.

[0083] S4: The AGV forklift follows the designated path navigation system to the unloading station, automatically identifies the pallet barcode, confirms the load information, and then loads the pallet and film roll onto the vehicle body;

[0084] The AGV forklift is equipped with a dual visual recognition system, including a QR code recognition module and a LiDAR scanning module, to accurately locate the pallet position and driving path;

[0085] The QR code recognition system uses the on-board camera to scan the label on the bottom of the pallet to obtain the pallet number and material roll product information; the lidar module simultaneously scans the ground and obstacles to build a real-time environmental map;

[0086] The vision system communicates with the AGV dispatching platform in real time, transmitting position data via the UDP protocol and refreshing it every 5 milliseconds to ensure optimal path selection. It automatically avoids obstacles and dynamically replans the path during driving to ensure that the pallet accurately reaches the target location.

[0087] In step S5, the AGV forklift accurately transports the film roll pallet to the designated curing furnace entrance or temporary buffer area according to the task instructions in the MES system. The task execution status is uploaded to the warehouse management system in real time.

[0088] When transferring film roll pallets to the curing furnace or buffer area, the AGV forklift uses a path planning algorithm based on the fusion of A-path search and the dynamic window algorithm (DWA) to pre-generate the optimal path before executing the task. During the transfer process, the AGV forklift can sense the operating status of other AGVs and environmental obstacles in real time to achieve collision avoidance and path replanning.

[0089] During the route planning process, each driving route is equipped with a transfer segment number and a timestamp recording mechanism. The WMS system dynamically adjusts the target curing furnace entry point based on the film roll curing time window and the waste heat utilization rate in the furnace.

[0090] If the current target furnace area is temporarily full, the AGV is instructed to enter the intermediate buffer area first, temporarily store it according to the preset FIFO rules, and regularly rearrange the transfer queue to ensure smooth logistics of the entire production line and no conflicts in tasks.

[0091] This mechanism effectively solves the problems of path interference and target point competition under multi-vehicle scheduling, and improves the overall stability of the system and resource utilization efficiency.

[0092] S6: After the AGV completes the transfer task, the truss robot control system resets and enters the standby state. After receiving the next film roll unloading instruction, it repeats S1 to S5 to ensure operation under closed-loop logic control to avoid scheduling conflicts.

[0093] After completing the film roll transfer task, the AGV forklift automatically drives to the empty pallet recycling area and performs the following steps:

[0094] First, the stacking height of empty pallets is identified through the pallet detection sensor. If the height exceeds the preset safety threshold, it automatically switches to the spare empty pallet stacking point; then the empty pallets are stacked to the standard height through the built-in lifting module, with no more than 6 layers per stack; finally, according to the instructions of the scheduling system, they are transported to the entrance of the pallet dismantling machine.

[0095] This process is completely unmanned, and all pallet flow data will be uploaded synchronously to the WMS warehouse management system to form a complete pallet cycle traceability record, improving system visualization and asset management capabilities.

[0096] Implementation 1: During the polyester (PET) film roll production process, the rolls are heavy and large after exiting the laminating machine, requiring high transport stability. Therefore, during the automated unloading and transfer process, coordinated scheduling between the gantry robot and the AGV system is crucial for smooth system operation. To address potential communication delays, command loss, and scheduling disruptions between the gantry robot and AGV, this implementation proposes a control architecture based on a central control synchronous signal bus. This architecture enables real-time sharing and distribution of critical control information via a high-speed, industrial-grade bus system.

[0097] The system integrates the gantry robot unloading controller, AGV dispatching terminal, MES execution platform, and WMS warehousing system into a unified bus architecture. The selected bus is an industrial Ethernet Profinet or EtherCAT system, which offers millisecond-level data response capabilities and high interference resistance, ensuring accurate data synchronization in high-speed and complex industrial environments. The system includes a central control management unit as the master node for signal dispatching, to which all control terminals connect as slaves.

[0098] During implementation, after the gantry robot completes the final action of removing the film roll and placing it on the pallet, it automatically generates an "action completed" signal through its built-in sensor. This signal is not transmitted over the standard TCP / IP network, but directly transmitted to the bus master via a hardware interrupt. Upon receiving this signal, the master immediately triggers the AGV dispatch response process, issuing the transfer task to the highest-priority idle AGV unit.

[0099] The greatest advantage of this architecture lies in its concise command chain, fast response, and unique transmission path. In traditional hierarchical network structures, gantry robots must upload information via local controllers to a central control platform, which then parses and distributes tasks to AGVs. This long path and multiple processing steps can easily cause information delays. In this approach, all nodes are arranged in parallel within a bus structure, and signal processing has real-time interrupt priority. The system can complete the generation and response of task instructions within tens of milliseconds, greatly reducing the error rate.

[0100] During each round of task scheduling, the central control management unit records each instruction's timestamp, signal content, execution unit number, response latency, and other data, forming a complete task flow log. This log can be used for later fault tracing and performance evaluation, and can be used to adjust priority parameters and optimize control strategies based on actual response characteristics during system upgrades.

[0101] In addition, the solution also incorporates a redundancy mechanism, namely, each AGV controller is equipped with a cache register. In the event of short-term bus congestion or controller failure, instructions can be retained locally and wait for self-check recovery in the next communication cycle, effectively enhancing the stability and robustness of the system.

[0102] Through the application of this embodiment, the entire polyester PET film roll unloading and sequencing process can achieve millisecond-level linkage, completely eliminating the risk of chain break between devices where "the action is completed but no one takes over", achieving true automated seamless connection, and effectively supporting large-scale, high-beat continuous production operations.

[0103] Implementation 2: In actual industrial applications, control structures that rely solely on one-time dispatch communications are highly susceptible to incidental factors, leading to control anomalies or scheduling losses. Therefore, this implementation, focusing on system stability and robustness, constructs a closed-loop dispatch control system with task self-detection, state feedback, and anomaly correction capabilities. This system manages the collaborative execution of gantry robots and AGVs in the automated unloading and reordering process for polyester (PET) film rolls.

[0104] In this architecture, each robotic unloading action doesn't simply end with mechanical placement itself; instead, it undergoes a complete closed-loop cycle: execution confirmation, dispatch response, and task completion. Upon completing an action, the truss robot not only sends a "completed" command but also generates a unique task identification code within its local control unit and simultaneously initiates a listening mode, awaiting an AGV response. If no AGV status confirmation (e.g., start, arrival, successful pallet identification, etc.) is received within the set listening time window, the system automatically triggers the task exception handling logic.

[0105] The exception handling mechanism includes the following: First, the system marks the status of the current task as "delayed response" and resends the scheduling instruction; second, if there is still no response after the resend, the system will immediately dispatch alternative AGV resources and set the original AGV allocation instruction to "failure recovery"; third, if two consecutive transfers fail, the truss robot system will suspend subsequent stacking to prevent pallet accumulation and overflow, and notify the operation management system for manual confirmation and processing.

[0106] The system also features a task status rollback mechanism. When the AGV completes a task, it sends a "pallet out confirmation" to the control platform. This feedback is used to verify the integrity of the preceding task's closed loop. If any intermediate states are missing or task status jumps, the system restructures the task chain, logs the current process, and conducts performance evaluation.

[0107] To improve overall fault tolerance, the system also features a scheduling fuzzy state recognition module. If an AGV encounters path deviation, low battery, or sensor failure during a mission, the system can identify and interrupt the mission, re-establishing it. Furthermore, each AGV supports a task lock mechanism to ensure task uniqueness and avoid scheduling duplication and logical confusion.

[0108] The closed-loop control system constructed in this way not only ensures the precise connection between the robot unloading and the AGV transfer action, but also significantly improves the system's stable operation and fault self-healing capabilities through full-process status monitoring and abnormal management logic, meeting the extremely high reliability requirements of high-intensity industrial scenarios.

[0109] Implementation Method 3: In the automated production of polyester (PET) film rolls, particularly when multiple laminating machines, gantry robots, and automated guided vehicles (AGVs) operate collaboratively, relying solely on fixed scheduling rules and static routing is insufficient to meet the complex scheduling requirements of high speed, flexibility, and interleaved processes. To address the potential command mismatches, response delays, and resource mismatches that can arise between gantry robots and AGVs during actual task execution, this implementation method proposes a comprehensive scheduling optimization method that integrates a task priority scoring system with a predictive path control algorithm.

[0110] The core of this method is to introduce an "intelligent dynamic scheduling engine", which is integrated into the system's AGV scheduling platform. It collects multi-dimensional data in real time, including truss robot unloading instructions, pallet status, film roll product parameters, current AGV operation status, remaining power, space occupancy, and task priority set in the production management system. Based on this, it makes a comprehensive scoring judgment and dynamically allocates the most suitable AGV to perform unloading and transfer tasks.

[0111] When the truss robot completes the film roll unloading action, the system will immediately generate a transfer task information, which includes key fields such as the film roll number, pallet number, starting position, target station, and maximum response time. After receiving the task, the scheduling engine will capture information on all currently idle or semi-idle AGV resources within milliseconds, including their current location, the status of the task being executed, the estimated completion time, the battery status, the number of tasks executed, etc. The system comprehensively ranks each AGV through a set multi-dimensional scoring formula to ensure that the equipment most suitable for the current task is dispatched first, rather than being allocated by fixed number or path, thereby effectively reducing resource waste and unnecessary waiting time.

[0112] In addition to a static scoring system, the system also integrates a predictive control model. This model uses historical route records, current equipment distribution, and task backlog to predict traffic density and queue lengths in major corridors and intersections within the next 1-2 minutes. If the highest-scoring AGV is detected about to enter a predicted high-latency area, the scheduling engine immediately skips it and selects the suboptimal path with the lowest scheduling cost, thus avoiding potential system stalls or path conflicts. This highly forward-looking mechanism ensures continuous task execution and system smoothness.

[0113] Furthermore, the system introduces a "task buffer pool" mechanism. Instead of immediately dispatching unloading signals from the gantry robot, it allows multiple tasks to accumulate over a certain period of time, then centrally schedules them based on the AGV's movement trends. For example, if an AGV is near a workstation and about to complete a task, the system can determine whether its path can also carry out a newly generated task in the vicinity. If so, it automatically incorporates this task into its path planning, forming a "multi-point collection, one-line delivery" path aggregation strategy. This significantly increases the output value of each AGV task execution and reduces idle and ineffective operations.

[0114] To support these intelligent scheduling capabilities, the system employs a task status awareness mechanism. Each dispatch execution records parameters such as task response time, actual route duration, wait time, and delays. All this data is analyzed and fed back to the scheduling scoring system for parameter fine-tuning, enabling model self-learning and continuous optimization of scheduling strategies. For example, if an AGV's response time is repeatedly slow under high load, the system will automatically lower its priority in subsequent scoring, reducing the frequency of its task assignments and ensuring balanced scheduling across the entire system.

[0115] In terms of deployment, the scheduling engine supports standardized protocol communication with MES systems, WMS systems, AGV control systems, and truss robot control systems. Task exchange follows the REST API interface specification, and all instructions have execution logs and receipt mechanisms to ensure that the entire system scheduling process is controllable and traceable.

[0116] This implementation enables dynamic scheduling, efficient path selection, and adaptive resource allocation in complex task environments within the automated production of polyester (PET) film rolls. This solution not only resolves the command synchronization issue between gantry robots and AGVs, but also enables the system to maintain extremely high operational efficiency and scheduling reliability even in high-frequency operations, intensive tasks, and complex paths, providing strong support for flexible scheduling in large-scale automated factories.

[0117] The present invention achieves high real-time and low-latency communication between the truss robot unloading control system and the AGV scheduling system by constructing a unified central control synchronization mechanism or high-frequency signal bus, breaking through the bottleneck problems such as network delay and instruction drift commonly seen in existing multi-system collaboration. The signal after each unloading action is completed can be received and responded to immediately by the AGV system at the millisecond level, avoiding a series of chain reactions such as pallet accumulation, task misordering, and transfer delays, greatly improving the stability and synchronization accuracy of the entire production line. This beneficial effect ensures the logical closed-loop execution of the automated process and is the key foundation for opening up the full-process control chain of "unloading-transfer-maturation".

[0118] The present invention introduces task status feedback, anomaly detection, and scheduling rollback mechanisms, establishing a complete closed-loop control system. This system can immediately identify the source of problems when a task is interrupted, an instruction is lost, or AGV scheduling fails, and automatically call upon backup AGV resources to restart the task, or, if necessary, roll back to the previous successful node for rescheduling. This mechanism effectively avoids system paralysis and production stagnation caused by single-point failures, improving the robustness and stability of the entire system. In a continuous, high-paced production environment, this beneficial effect ensures seamless connectivity between devices, improving the overall operational efficiency and risk resistance of the entire line.

[0119] By introducing an AGV priority scoring model and a predictive control algorithm, this invention completes data collection, real-time calculation, and path planning before task scheduling. It effectively integrates multi-dimensional information such as film roll weight, transfer distance, vehicle status, and task timing, and combines historical task data to predict system latency trends, ensuring that each AGV call is based on optimal resource allocation. This strategy not only improves the efficiency of single-task execution but also avoids AGV resource idling, congestion, and scheduling conflicts, making the entire unloading and sequencing process more intelligent and adaptive. This beneficial effect significantly improves the flexible adjustment capability of the production rhythm and the comprehensive utilization rate of system resources.

[0120] The above formulas are all dimensionless and numerical calculations. The formulas are obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The preset parameters in the formulas are set by technicians in this field according to actual conditions.

[0121] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

[0122] It should be noted that, in this document, if there are relational terms such as first and second, etc., they are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0123] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0124] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0125] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0126] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0127] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0128] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

[0129] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A method for automatically unloading and transferring polyester PET film rolls, characterized in that: The following steps are involved: S1: A truss robot receives unloading instructions from the production management system. After the laminating machine completes the production of a roll of polyester film, the truss robot removes the film roll from the winding station and places it on a dedicated tray with a positioning and limiting structure. S2, when the truss robot completes the unloading action, the unloading control system generates an unloading completion signal, which is sent to the AGV scheduling system through the intermediate communication interface; S3, after receiving the unloading completion signal, the AGV scheduling system calls the preset path rules and transfer priority strategy, selects the corresponding idle AGV forklift from the AGV task pool, and assigns it to perform the current transfer task; S4: The AGV forklift follows the designated path navigation system to the unloading station, automatically identifies the pallet barcode, confirms the load information, and then loads the pallet and film roll onto the vehicle body; In step S5, the AGV forklift accurately transports the film roll pallet to the designated curing furnace entrance or temporary buffer area according to the task instructions in the MES system. The task execution status is uploaded to the warehouse management system in real time. S6: After the AGV completes the transfer task, the truss robot control system resets and enters the standby state. After receiving the next film roll unloading instruction, it repeats S1 to S5 to ensure operation under closed-loop logic control to avoid scheduling conflicts. The control system is equipped with a multi-system synchronous control logic module, the core of which is the timestamp synchronization algorithm. Each unloading event will record the precise timestamp after the truss robot completes the last action node, and record the response time of the AGV scheduling system after receiving the signal. If the response time is subtracted from the time when the robot completes the last action node, the time will be the same as the response time. , the control system will trigger the synchronous exception handling mechanism, automatically start the backup AGV or resend the instruction to avoid task accumulation; In order to ensure the system scheduling stability and response time accuracy, a scheduling response correction mechanism based on PID+ prediction algorithm is added to the control system. The specific steps are as follows: The scheduling response correction mechanism of the task signal delay target value algorithm is set. The specific steps are as follows: Set the target value of task signal delay , where is the error term; Set the scale factor , integral coefficient , differential coefficient , calculate the adjustment parameters, the calculation expression is as follows: , where Is the proportional coefficient, which is used to determine the direct proportional relationship of the error term in the control output. is the integral coefficient, which is used to accumulate the trend of error over time and eliminate static error. Is the differential coefficient, which is sensitive to the rate of change of the error and is used to predict trends in advance. is the PID controller at time The regulation signal given, Is an imaginary time variable, representing the time from the start time 0 to the moment A scan variable of At every point in time The systematic error on is a tiny time increment; The time series prediction model AR(1) is used to estimate the delay of the next cycle. The delay calculation formula is as follows: , where is the next cycle prediction delay, is the delayed autocorrelation coefficient, is the model offset correction; Adjust the thread scheduling priority of the signal relay server. The formula is as follows: , where It is a comprehensive indicator of scheduling priority; when hour, It is a preset tolerance threshold that triggers the main control system to switch to the backup relay server to ensure the continuity of command transmission and real-time response; During the execution of the unloading and transfer task, the AGV scheduling priority is optimized in real time. The specific steps are as follows: Assume that the weight of the film roll is , the pallet weight is , calculate the total load, the calculation expression is as follows: , where is the total load weight; The estimated time for film roll to be taken out of the oven is , the current time is , calculate the waiting time, the calculation expression is as follows: , where It’s waiting time; Set the current position of each AGV , the target unloading point position is , calculate the Euclidean distance, the calculation expression is as follows: , where and It is The current position coordinates of the AGV forklift, and is the coordinate of the target unloading point, It is The Euclidean distance between the AGV and the target point; According to the remaining power of each AGV , speed coefficient , load factor , the scheduling priority score is obtained, and the calculation expression is as follows: , where It is The scheduling priority score of each AGV, load factor, ; Select the largest one among all idle AGVs The corresponding AGV performs the current task, and the remaining vehicles enter the waiting queue.

2. The automatic unloading and reordering method for polyester PET film rolls according to claim 1, characterized in that: The truss robot adopts a three-axis linkage structure, corresponding to axis, Axis and Axis direction, and integrated with a set of variable position handling fixtures, the fixtures have dual functions: one is to hook the core shaft of the film roll through the rotating hook structure to achieve heavy-load lifting; the other is to grab the core shaft through the parallel clamping claw structure to complete the extraction and re-insertion action; Whenever the robot performs the action before unloading, its control system automatically adjusts the distance between the clamps according to the film roll diameter and core shaft length data issued by MES to ensure handling stability and unloading accuracy.

3. The automatic unloading and reordering method for polyester PET film rolls according to claim 1, characterized in that: The pallet is equipped with a two-way limiting groove structure and an adjustable wedge-shaped limiting block. Three symmetrically distributed limiting tracks are preset on the surface of each pallet for stacking three film rolls in a "pin" shape. Each wedge-shaped limit block is connected to the track through a sliding buckle device, and the sliding distance is accurately marked by the coding ruler at the bottom of the tray; When the truss robot performs the stacking action, the limit block displacement program is automatically called according to the film roll specifications, so that both ends of each film roll are stably supported by the limit blocks; The limiting structure also has an anti-seismic cushion layer, which effectively absorbs the micro-vibration generated during transportation and prevents the film roll from shifting or overturning, thereby ensuring stacking safety and transportation stability.

4. The method for automatically unloading and transferring polyester film rolls according to claim 1, characterized in that: The AGV forklift is equipped with a dual visual recognition system, including a QR code recognition module and a LiDAR scanning module, to accurately locate the pallet position and driving path; The QR code recognition system uses the on-board camera to scan the label on the bottom of the pallet to obtain the pallet number and material roll product information; the lidar module simultaneously scans the ground and obstacles to build a real-time environmental map; The vision system communicates with the AGV dispatching platform in real time, transmitting position data via the UDP protocol and refreshing it every 5 milliseconds to ensure optimal path selection. It automatically avoids obstacles and dynamically replans the path during driving to ensure that the pallet accurately reaches the target location.

5. The automatic unloading and reordering method for polyester PET film rolls according to claim 1, characterized in that: When transferring film roll pallets to the curing furnace or buffer area, the AGV forklift uses a path planning algorithm based on the fusion of A-path search and dynamic window method to pre-generate the optimal path before executing the task. During the transfer process, it also senses the operating status of other AGVs and environmental obstacles in real time to achieve collision avoidance and path replanning. During the route planning process, each driving route is equipped with a transfer segment number and a timestamp recording mechanism. The WMS system dynamically adjusts the target curing furnace entry point based on the film roll curing time window and the waste heat utilization rate in the furnace. If the current target furnace area is temporarily full, the AGV is instructed to enter the intermediate buffer area first, temporarily store it according to the preset FIFO rules, and regularly rearrange the transfer queue to ensure smooth logistics of the entire production line and no conflicts in tasks.

6. The method for automatically unloading and transferring polyester film rolls according to claim 1, characterized in that: After completing the film roll transfer task, the AGV forklift automatically drives to the empty pallet recycling area and performs the following steps: The pallet detection sensor identifies the stacking height of empty pallets. If the height exceeds the preset safety threshold, it automatically switches to the standby empty pallet stacking point; Empty pallets are stacked to a standard height using a built-in lifting module, with no more than 6 layers per stack; According to the instructions of the dispatching system, transport to the entrance of the disassembly machine.

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