Multi-plc cooperative control based on the wheat kiln unattended system and method

Abstract

This invention discloses an unattended system and method for wheat kiln based on multi-PLC collaborative control, belonging to the field of automatic control technology. It aims to solve the technical problems of low efficiency, large errors, and high safety hazards associated with traditional manual operation of wheat kilns, and the difficulty of single-PLC control meeting the complex process requirements. The system includes: a central control layer, comprising a central control system PLC and a host computer system, for global monitoring, command issuance, and data aggregation; a process execution layer, for controlling the operation of equipment throughout the entire wheat kiln production process, realizing automated operation of each stage of feeding, batching, processing, unloading, and packaging, and real-time monitoring and feedback of key parameters; and an auxiliary control layer, for collaborative communication between the PLCs of each subsystem. In this invention, the system constructs a three-level PLC collaborative architecture, significantly shortening the command response time between stages, accurately matching parameters of each stage, completely eliminating problems such as command lag and imbalance caused by information silos, improving production efficiency, and achieving unattended operation.

Description

Technical Field

[0001] This invention relates to the field of automatic control technology, and more specifically, to an unattended system and method for wheat kiln based on multi-PLC collaborative control. Background Technology

[0002] The production of wheat kilns involves several closely related stages, including feeding, batching, baking, unloading, packaging, and storage. The coordinated operation of equipment in each stage is crucial to production efficiency and finished product quality. Especially in the humid and rainy production season in the south, the damp environment can easily lead to fluctuations in the moisture content of raw materials, moisture damage to equipment circuits, and corrosion of mechanical parts, posing additional challenges to production stability.

[0003] Currently, there is a significant technical problem in the production of wheat kilns: the control of each link relies on independent control systems, and the equipment in links such as feeding, batching, and baking lacks efficient data interaction and coordination mechanisms, resulting in delayed command response and low parameter matching accuracy between links.

[0004] When the feed rate drops sharply due to raw materials clumping from moisture, the independent batching system cannot obtain data in real time to adjust the proportions, easily leading to material imbalance. In the baking process, the temperature curve needs dynamic adjustment due to humidity changes, but this cannot be linked to the feeding device, potentially causing high-temperature material accumulation and equipment overload shutdown, severely restricting production efficiency and stability, and making full unattended operation impossible. Therefore, we propose an unattended wheat kiln system and method based on multi-PLC collaborative control. Summary of the Invention

[0005] The purpose of this invention is to provide an unattended system and method for wheat kiln based on multi-PLC collaborative control, so as to solve the technical problems of low efficiency, large error, high safety hazards, and difficulty in meeting the complex process requirements of traditional manual operation of wheat kiln.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an unattended wheat kiln system based on multi-PLC collaborative control, comprising:

[0007] The central control layer, including the central control system PLC and the host computer system, is used for global monitoring, command issuance, and data aggregation.

[0008] The process execution layer is used to control the operation of equipment throughout the entire production process of the wheat kiln, realize the automated operation of each link of feeding, batching, processing, unloading and packaging, and monitor key parameters in real time and provide feedback.

[0009] The auxiliary control layer is used to realize the functions of controlling the wheat silo equipment, executing the dust removal process, lifting and weighing materials, and managing finished product storage through the coordinated communication of PLCs in various subsystems.

[0010] The central control layer communicates with the process execution layer and the auxiliary control layer at high speed via the ProfinetIRT protocol.

[0011] In this invention, the system employs a three-tiered PLC collaborative architecture comprising a central control layer, a process execution layer, and an auxiliary control layer. At the process execution layer, the feeding system PLC communicates in real-time with the automatic batching system PLC, dynamically feeding back silo weight data. The kiln control PLC acts as the data hub, aggregating parameters from the entire process, including feeding, batching, and baking, and interacting bidirectionally with the central control system PLC. Leveraging the high-speed transmission capabilities of industrial Ethernet, the system establishes a cross-layered information highway, significantly reducing command response time between stages, accurately matching parameters at each stage, and completely eliminating problems such as command lag and proportion imbalance caused by information silos, thereby improving production efficiency and achieving unmanned operation.

[0012] Preferably, the central control system PLC communicates bidirectionally with the host computer system, supports remote client data interaction, and the central control system PLC has a built-in instruction arbitration function module for handling multi-PLC instruction conflicts.

[0013] Preferably, the process execution layer includes:

[0014] The feeding system PLC controls the operation of the feeding equipment, communicates with the automatic batching system PLC, and provides feedback on the weight of the hopper.

[0015] The automatic batching system PLC sets the batching ratio according to remote instructions, controls the seeding mechanism and records the track weight, and feeds back to the main control PLC of the wheat kiln.

[0016] The robot PLC controls the robot to feed wheat into the wheat kiln tube, monitors the furnace temperature, pressure and finished product weight, and feeds back to the wheat kiln's main control PLC.

[0017] The main control PLC of the maiya kiln summarizes the parameters of each link, communicates with the central control system PLC, and executes global instructions.

[0018] The PLC feeding system controls the tipping of the roasted wheat and its conveying to the baling machine, records the baling weight, and performs weight compensation.

[0019] The packaging system is linked to a PLC to monitor the packaging weight and is coordinated with the unloading system PLC to automatically stop the machine in case of abnormal weight.

[0020] The feeding system PLC communicates with the automatic batching system PLC via control signals, and the robot PLC, the unloading system PLC, and the kiln master control PLC are connected via EtherCAT bus.

[0021] Preferably, the auxiliary control layer includes a lower wheat silo PLC, a dust removal PLC, an elevator PLC, and a finished product warehouse PLC;

[0022] The PLC for the lower wheat silo communicates with the PLC for the feeding system in the process execution layer, the PLC for the dust removal system in the auxiliary control layer, the PLC for the elevator, and the PLC for the finished product warehouse to control the operation of the lower wheat silo equipment.

[0023] The dust removal PLC communicates with the lower wheat silo PLC and the finished product warehouse PLC to execute the dust removal process;

[0024] The elevator PLC communicates with the lower wheat silo PLC and the finished product warehouse PLC to realize material lifting and weighing data feedback.

[0025] The finished product warehouse PLC includes a finished product warehouse process PLC, a finished product warehouse communication PLC, and a finished product warehouse host computer station, which communicates with the lower warehouse PLC and the elevator PLC to control the finished product storage.

[0026] Preferably, the wheat silo PLC includes a wheat silo process PLC, a wheat silo communication PLC, and a host computer wheat silo station;

[0027] The PLC for the wheat silo process is used to control the operation of the wheat silo equipment and coordinate the orderly operation of each piece of equipment.

[0028] The Xiamaicang Communication PLC is used to realize data interaction and signal transmission between the Xiamaicang PLC and other PLC systems.

[0029] The host computer station for the wheat silo is used to provide a human-machine interface to monitor the operating status of the wheat silo equipment, set parameters, and set fault alarms.

[0030] Preferably, the dust removal PLC includes a dust collector communication PLC, a dust removal control PLC, and a dust removal host computer communication station;

[0031] The dust collector communication PLC is used to communicate with other PLC systems to obtain operating parameters and instructions;

[0032] The dust removal control PLC is used to control the operation of the dust collector and adjust the working status of the dust removal equipment.

[0033] The dust removal host computer communication station is used to realize data interaction between the dust removal system and the host computer, which facilitates operators to monitor and manage the dust removal equipment.

[0034] Preferably, the hoist PLC includes a weighing communication PLC, a weighing calculation PLC, and a host computer hoist station;

[0035] The weighing communication PLC is used for data communication with other PLCs and weighing equipment to transmit weighing-related information;

[0036] The weighing calculation PLC is used to process the weighing sensor data, calculate the material weight, and perform data verification and correction.

[0037] The host computer hoisting station is used to monitor the hoisting machine's operating status and weighing data in real time, enabling remote operation and fault diagnosis.

[0038] A method for unattended operation of a wheat kiln based on multi-PLC collaborative control includes the following steps:

[0039] S1. System initialization: Configure the parameters of each PLC communication board, set the communication protocol, create function blocks and data areas, and build the foundation for bidirectional communication between the upper and lower computers.

[0040] S2. Full-process collaborative control: Implement automated management and control of the entire production process of the wheat kiln, including feeding and batching, baking and robot operation, unloading, packaging and storage stages, to ensure accurate execution and parameter compliance in each link;

[0041] S3. Monitoring and Anomaly Handling: Real-time integration and display of production data, enabling multi-PLC linkage control and automatic response to abnormal situations.

[0042] Preferably, step S2 further includes the following steps:

[0043] S201: Feeding and batching stage: The feeding system PLC calculates the total material intake and feeds it back to the automatic batching system PLC. The automatic batching system PLC adjusts the batching weight of each track according to the preset ratio to ensure that the total weight converges to the target value.

[0044] S202: Baking and Robot Operation Stage: The robot PLC feeds wheat into the wheat kiln tube, calibrates the feeding deviation, monitors the furnace temperature sequence and pressure curve, and adjusts parameters or triggers an alarm when abnormalities occur.

[0045] S203: Material feeding, packaging and storage stage: The material feeding system PLC controls the finished product to be conveyed to the packaging machine and performs weight compensation. The PLC of the unloading silo, the elevator PLC and the finished product warehouse PLC work together to complete the warehousing, dust removal and storage management.

[0046] Preferably, the exception handling in step S3 includes:

[0047] Minor anomaly: If a single parameter deviates from the set range, a local alarm will be triggered and continuous monitoring will be performed;

[0048] Serious anomaly: Multiple parameters exceed limits; shut down and save current parameters.

[0049] Emergency malfunction: When the safety threshold is reached, the power supply is cut off and the fire alarm system is activated.

[0050] Shutdown sequence: First stop the material feeding and furnace tubes in the process execution layer, then stop the elevator and dust removal equipment in the auxiliary control layer.

[0051] Compared with the prior art, the beneficial effects of the present invention are:

[0052] 1. In this invention, the system constructs a three-tiered PLC collaborative architecture comprising a central control layer, a process execution layer, and an auxiliary control layer. At the process execution layer, the feeding system PLC communicates in real-time with the automatic batching system PLC, dynamically feeding back silo weight data. The kiln control PLC acts as the data hub, aggregating parameters from the entire process, including feeding, batching, and baking, and interacting bidirectionally with the central control system PLC. Leveraging the high-speed transmission capabilities of industrial Ethernet, the system establishes a cross-layered information highway, significantly shortening the command response time between stages, accurately matching parameters at each stage, and completely eliminating problems such as command lag and proportion imbalance caused by information silos, thereby improving production efficiency and achieving unmanned operation.

[0053] 2. This invention also utilizes the intelligent instruction arbitration module built into the central control system PLC, employing a three-tiered priority mechanism: safety instructions, global instructions, and local instructions. When the system is running, if a conflict arises between the central instructions and the local instruction parameters of the Maiyao main control PLC, the arbitration module will immediately activate the conflict detection algorithm, locking the priority difference within milliseconds, retaining the higher-priority instruction, and sending an "instruction invalidation" signal to the lower-priority instruction. Simultaneously, the system records a conflict log, facilitating traceability and analysis by maintenance personnel, fundamentally preventing control disruptions caused by instruction conflicts, and significantly improving the stability and reliability of multi-stage collaborative operations.

[0054] 3. This invention also enhances adaptability to humid environments. Under high humidity conditions, the auxiliary control layer constructs an intelligent dust removal closed-loop system. The dust removal PLC, the lower wheat silo PLC, and the finished product warehouse PLC are linked in real time. By dynamically adjusting the pulse jet frequency and interval, the amount of dust accumulation is controlled within a safe threshold, effectively preventing humid dust from adhering to and clogging key equipment components. The high-precision weighing module on the elevator and the weighing calculation PLC form a dual verification mechanism. The Kalman filter algorithm is used to reduce noise and correct sensor data in real time, which can reduce the weighing error rate caused by humid environments. Through the upgrade of the moisture-proof coating process and the optimization of the sealing structure, the mean time between failures (MTBF) of the equipment is improved, ensuring the stable unattended operation of the multi-PLC collaborative system in humid environments. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0056] Example 1: As Figure 1 As shown, the present invention relates to an unattended wheat kiln system based on multi-PLC collaborative control, comprising a central control layer, a process execution layer and an auxiliary control layer, wherein each layer communicates through a multi-bus protocol;

[0057] The central control layer, including the central control system PLC and the host computer system, is used for global monitoring, command issuance, and data aggregation.

[0058] In an embodiment of the present invention, the central control system PLC communicates bidirectionally with the host computer system, supporting remote client data interaction:

[0059] The central control system PLC is used for equipment logic control, data acquisition and local processing. It achieves precise control of field equipment through preset programs, and transmits real-time data to the host computer.

[0060] The central control system PLC has a built-in instruction arbitration module for handling instruction conflicts between multiple PLCs.

[0061] Define three levels of instruction priority:

[0062] Level 1 (Safety Instructions): Pressure over-limit shutdown and temperature surge protection, directly triggered by any PLC, with a mandatory response from the central control layer;

[0063] Level 2 (Global Instructions): Production plan adjustment instructions issued by the central control system PLC, covering local instructions at the process execution layer and auxiliary control layer;

[0064] Level 3 (Local Instructions): Local optimization instructions for each PLC (such as fine-tuning the feeding speed), executed only when there are no conflicts with higher-level instructions.

[0065] When an instruction conflict is detected (such as a contradiction between the central instruction and the local instruction parameters of the Maiyao main control PLC), the high-priority instruction is retained and a "instruction invalid" signal is sent to the low-priority PLC. At the same time, the conflict log is recorded to the host computer system.

[0066] The host computer system is used for visual data display, human-computer interaction, system parameter configuration, and data analysis and decision-making. It provides operators with an intuitive monitoring interface and supports remote access and command issuance.

[0067] The process execution layer is used to control the operation of equipment throughout the entire production process of the wheat kiln, realizing automated operation of each link of feeding, batching, processing, unloading and packaging, monitoring key parameters in real time and providing feedback, ensuring the orderly progress of the production process and the quality of finished products meeting standards.

[0068] In an embodiment of the present invention, the process execution layer includes a feeding system PLC, an automatic batching system PLC, a robot PLC, a kiln control PLC, a discharging system PLC, and a packaging association PLC;

[0069] The feeding system PLC controls the operation of the feeding equipment, communicates with the automatic batching system PLC, and provides feedback on the weight of the hopper.

[0070] The automatic batching system PLC sets the batching ratio according to remote instructions, controls the seeding mechanism and records the track weight, and feeds back to the main control PLC of the wheat kiln.

[0071] The robot's PLC controls the robot to feed wheat into the wheat kiln tubes and monitors the furnace temperature. ),pressure( The weight of the finished product and the data are fed back to the main control PLC of the wheat kiln.

[0072] The main control PLC of the maiya kiln summarizes the parameters of each link, communicates with the central control system PLC, and executes global instructions.

[0073] The PLC feeding system controls the tipping of the roasted wheat and its conveying to the baling machine, records the baling weight, and performs weight compensation.

[0074] The packaging system is linked to a PLC to monitor the packaging weight and works in conjunction with the material unloading system PLC to automatically stop the machine in case of abnormal weight.

[0075] The auxiliary control layer is used to realize functions such as controlling the wheat silo equipment, executing dust removal processes, lifting and weighing materials, and managing finished product storage through collaborative communication between the PLCs of various subsystems.

[0076] In an embodiment of the present invention, the auxiliary control layer includes a lower wheat silo PLC, a dust removal PLC, an elevator PLC, and a finished product warehouse PLC;

[0077] The PLC for the lower wheat silo communicates with the PLC for the material feeding system in the process execution layer, the PLC for the dust removal system in the auxiliary control layer, the PLC for the elevator, and the PLC for the finished product warehouse to control the operation of the lower wheat silo equipment.

[0078] The wheat warehouse PLC includes a wheat warehouse process PLC, a wheat warehouse communication PLC, and a host computer wheat warehouse station;

[0079] The wheat silo process PLC is used to control the operation of the wheat silo equipment and coordinate the orderly operation of each piece of equipment.

[0080] The Xiamaicang Communication PLC is used to realize data interaction and signal transmission between the Xiamaicang PLC and other PLC systems.

[0081] The host computer for the wheat silo station provides a human-machine interface to monitor the operating status of the wheat silo equipment, set parameters, and trigger fault alarms.

[0082] The dust removal PLC communicates with the PLCs in the wheat silo and finished product warehouse to execute the dust removal process.

[0083] The dust removal PLC includes a dust collector communication PLC, a dust removal control PLC, and a dust removal host computer communication station;

[0084] The dust collector communication PLC is used to communicate with other PLC systems to obtain operating parameters and instructions;

[0085] The dust removal control PLC is used to control the operation of the dust collector, adjust the working status of the dust removal equipment, and ensure the dust removal effect.

[0086] The dust removal host computer communication station is used to realize data interaction between the dust removal system and the host computer, so as to facilitate operators to monitor and manage the dust removal equipment.

[0087] The elevator PLC communicates with the PLCs of the lower wheat silo and the finished product warehouse to realize material lifting and weighing data feedback;

[0088] The hoist PLC includes a weighing communication PLC, a weighing calculation PLC, and a host computer hoist station;

[0089] The weighing communication PLC is used to communicate data with other PLCs and weighing equipment to transmit weighing-related information.

[0090] The weighing calculation PLC is used to process weighing sensor data, calculate the weight of materials, and perform data verification and correction.

[0091] The host computer hoisting station is used to monitor the hoisting machine's operating status and weighing data in real time, enabling remote operation and fault diagnosis.

[0092] The finished product warehouse PLC communicates with the wheat silo PLC and the elevator PLC to control the finished product storage.

[0093] The finished goods warehouse PLC includes a finished goods warehouse process PLC, a finished goods warehouse communication PLC, and a finished goods warehouse host computer station;

[0094] Finished goods warehouse process PLC is used to manage the processes of finished goods warehouse receiving, issuing, and storage, ensuring that warehousing operations are carried out in an orderly manner;

[0095] The finished goods warehouse communication PLC is used to enable data exchange between the finished goods warehouse PLC and other PLC systems, and to collaboratively complete warehouse management tasks.

[0096] The finished goods warehouse supervisory control station provides a finished goods warehouse management interface, enabling inventory data monitoring, inbound and outbound record querying, and warehouse equipment control.

[0097] The instruction priority of each communication PLC in the auxiliary control layer is divided into four levels (from high to low):

[0098] Safety commands: Dust removal system overload shutdown, hoist overload protection (directly triggered by dust removal PLC and hoist PLC, forcibly overriding other commands);

[0099] Production process instructions: feeding / discharging control of the lower wheat silo (lower wheat silo communication PLC), and finished product warehouse inbound scheduling (finished product warehouse communication PLC).

[0100] Auxiliary process instructions: Dust removal intensity adjustment (dust removal communication PLC), elevator speed fine adjustment (elevator communication PLC);

[0101] Status query command: Acquire equipment operating parameters (applicable to all communication PLCs).

[0102] When an instruction conflict is detected, the low-priority PLC immediately terminates the current instruction, sends an 'instruction acceptance confirmation' signal to the high-priority PLC, and records the conflict in the log.

[0103] In an embodiment of the present invention, the communication architecture is as follows:

[0104] The central control layer communicates with the process execution layer and the auxiliary control layer using the ProfinetIRT protocol for high-speed bidirectional communication.

[0105] Within the process execution layer: the feeding system PLC and the automatic batching system PLC communicate via control signals, while the robot PLC, the unloading system PLC, and the main control PLC of the wheat kiln are connected via EtherCAT bus;

[0106] Within the auxiliary control layer: the PLC for the lower wheat silo communicates with the PLC for dust removal and the PLC for finished product storage via Msub / CANlink; the PLC for the lower wheat silo communicates with the PLC for the elevator via Profinet dual-channel communication (uplink RT, downlink IRT); the PLC for dust removal communicates with the PLC for finished product storage via EtherCAT bus; and the PLC for elevator communicates with the PLC for finished product storage via Profinet bus.

[0107] Between the process execution layer and the auxiliary control layer: the feeding system PLC and the unloading silo PLC communicate via the ProfinetRT protocol, and the feeding system PLC is linked with the elevator PLC and the finished product warehouse PLC;

[0108] In particular, a protocol conversion gateway is added to the communication nodes between the auxiliary control layer and the process execution layer (such as the wheat warehouse PLC and the material feeding system PLC) to clarify the mapping rules:

[0109] The 8-bit status code of Msub / CANlink corresponds to the 16-bit status register of ProfinetRT (e.g., "0x01" indicates that the device is running, which is mapped to "0x0001").

[0110] Timing compensation for different protocols: The 10ms delay of Msub / CANlink is offset by the early triggering mechanism of ProfinetIRT (attaching a -10ms timestamp when sending commands).

[0111] Cross-layer communication (such as between the process execution layer and the auxiliary control layer) adopts "dual-link + heartbeat detection":

[0112] The main link (ProfinetRT) transmits real-time data, while the backup link (EtherCAT) transmits verification frames.

[0113] Each PLC sends a heartbeat packet every 50ms. If it fails to receive the heartbeat packet three times in a row, it will trigger a link switch. An alarm will be automatically triggered when the packet loss rate exceeds 5%.

[0114] Enable 'double buffering + timestamp alignment' mechanism during link switching:

[0115] When the main link is normal, real-time data is synchronously written to the main buffer (capacity 100ms), and the verification frames of the backup link synchronously record the data timestamp (accurate to 1ms).

[0116] After the link switch is triggered, the backup link immediately reads the last 50ms of data in the main cache and fills in the missing data based on the timestamp of the verification frame (if the timestamp of the verification frame and the main cache data deviates by more than 5ms, the data of the backup link shall prevail).

[0117] After the switch is completed, the central control system PLC performs consistency verification on three consecutive sets of data before and after the switch (deviation ≤1% is considered valid). If the verification fails, data reconstruction is triggered (based on the trend fitting and completion of the previous 10 seconds).

[0118] Example 2: A method for unattended operation of a wheat kiln based on multi-PLC collaborative control, specifically including the following steps:

[0119] S1: System initialization: Configure the parameters of each PLC communication board, set the communication protocol, create function blocks and data areas, and build the foundation for bidirectional communication between the upper and lower computers;

[0120] In another embodiment of the present invention, step S1 further includes the following steps:

[0121] S101: Configure the communication board parameters of each PLC: The PLC for the wheat bin process and the communication PLC adopt EtherCAT bus and Msub / CANlink mode; the PLC for dust removal control and the PLC for dust collector communication adopt EtherCAT bus; the PLC for the hoist weighing communication and the PLC for calculation adopt ProfinetRT protocol.

[0122] S102: Set the communication protocol: The central control system PLC and each execution layer PLC use ProfinetIRT, and the auxiliary control layer internally uses a hybrid protocol of Msub / CANlink and Profinet.

[0123] S103: Create PLC function blocks, communication protocols, and variable data areas to achieve bidirectional communication between the upper and lower level computers (dual PLC configuration).

[0124] S2: Full-process collaborative control: Automated management and control of the entire wheat kiln production process to ensure precise execution and parameter compliance at each stage.

[0125] In another embodiment of the present invention, step S2 further includes the following steps:

[0126] S201: Feeding and Batching Stage: Controlling the total amount of wheat fed and the batching of ingredients on each track to ensure that the material ratio meets production requirements; the trigger threshold for the feeding system PLC to send a "feeding complete" signal to the automatic batching system PLC: total material handling volume. achieve 98% and stable for 2 seconds (avoiding misjudgment of material residue);

[0127] Step S201 further includes the following steps:

[0128] S201a: The PLC of the feeding system transports wheat to the hopper of the automatic batching system through the material handling subsystem and the metering subsystem, and calculates the total material handling volume. (In the formula, This represents the material intake quantity for each track, collected in real time by the metering subsystem. This data is used to monitor the total material intake and ensure that production needs are met. The formula is based on the fundamental mathematical principle that "the total material intake equals the sum of the material intake quantities of each track," and is applicable to total quantity statistics in multi-track material intake scenarios. Referring to the summation model commonly used in industrial metering, let the material intake quantities for the 10 tracks be... Unit: kg, total material taken (This is the cumulative value of the material taken from each track), and it is fed back to the PLC of the automatic batching system in sequence.

[0129] S201b: The automatic batching system PLC controls the sowing mechanism to place the wheat onto the track according to the ratio set by the remote client, and records the track weight. ( These correspond to the real-time weight of wheat on different tracks, used to precisely control the amount of material fed onto each track.

[0130] Through formula Adjust the weights, where, Given the preset total batching target weight, the algorithm compares the difference between the actual weight and the target weight of each track, finds the track with the smallest difference, and dynamically adjusts the batching weight of each track in combination with other relevant parameters to ensure that the final batching total matches the target value, and feeds the adjusted result back to the main control PLC of the mai kiln.

[0131] This formula is based on the principle of "prioritizing the adjustment of minimum deviation" and references the deviation compensation algorithm in adaptive control. It is used to dynamically balance the difference between the material quantity of each track and the target value, so that the actual weight of each track is... As close as possible to the target total weight The assigned value, defining the deviation. ( ), and select the minimum deviation The corresponding track should be the priority for adjustment, and its adjustment weight should be based on historical data. The average value of the tracks produced in the last three production runs, and the real-time deployment volume. ) and material characteristic parameters ( The humidity correlation coefficient, (where the density correlation coefficient is used), and the total weight convergence is ultimately achieved through minimum deviation matching, i.e. ;

[0132] S202: Baking and Robot Operation Stage: Controlling the wheat baking process to ensure that the amount of materials fed, temperature and pressure meet the process safety standards;

[0133] Step S202 further includes the following steps:

[0134] S202a: The robot PLC feeds wheat onto the track into the wheat kiln tube and calibrates the actual value. With calibration value deviation ( This refers to the actual weight of wheat fed into the kiln tube. (The ideal weight is set according to the production process). Then adjust the control parameters to ensure that the amount of material fed in meets the process requirements;

[0135] This formula is based on the definition of "absolute deviation between actual and target values," referencing the fundamental deviation model in error analysis, and is used to evaluate the accuracy of delivery volume and calibration values. Compared with the actual calibration value The difference is the deviation. The unit is kg. When the delivery volume is deemed to be out of tolerance, parameter adjustments are triggered.

[0136] S202b: Monitoring furnace temperature: Judgment and temperature sequence Ascending and descending order rules;

[0137] in, These represent temperature values ​​at different locations within the furnace or at different monitoring times. Used to determine the initial trend of temperature change;

[0138] The ascending and descending order rules are used to monitor whether the temperature changes according to the preset process curve during the baking process, and to remotely suspend production in case of abnormalities.

[0139] warming period: (Temperature difference per level ≤ 2℃), an alarm will be triggered if the deviation continues for 10 seconds;

[0140] Insulation period: (and and , This refers to the furnace outlet temperature, with the upper limit preset based on the wheat variety (default 50℃). If the temperature is abnormal, the robot PLC immediately reduces the furnace tube feeding speed by 20% and triggers... Special alarm (feedback to Maiyao's main control PLC);

[0141] Disorder is defined as meeting any of the following conditions:

[0142] The heating period did not meet the requirements for two consecutive sampling cycles (1 second each). The ascending order;

[0143] The insulation period does not meet the requirements for two consecutive sampling cycles. The descending order relation;

[0144] Any adjacent temperature points (e.g.) and , and The absolute value of the temperature difference And it lasts for 3 seconds.

[0145] S202c: Monitoring furnace pressure: Generating pressure growth curves through linear fitting ( , (Pressure values ​​at different monitoring points or at different times within the furnace, in kPa, used to construct pressure change models).

[0146] Pressure exceeds limit: If or ( The preset pressure increase threshold, (the maximum safe pressure value), and the furnace temperature conditions during the heating period meet ( When this occurs, immediately initiate the pressure relief logic;

[0147] If the pressure exceeds the limit but the furnace temperature conditions are met during the cooling phase ( When the temperature is abnormal, first trigger the temperature alarm, then delay for 5 seconds before releasing the pressure.

[0148] After depressurization, the pressure returned to At the same time, the robot's PLC adjusts the furnace tube feeding speed (reducing it by 10%) to maintain stable pressure and ensure that the furnace pressure is within a safe range.

[0149] S203: Feeding, Packaging and Storage Stage: Accurate feeding, packaging and storage management of finished wheat products to ensure closed-loop operation of the production process;

[0150] Step S203 further includes the following steps:

[0151] S203a: The PLC feeding system conveys the finished wheat through a tipping bucket to the baler, records the weight, compares it with the preset ratio, and compensates for any discrepancies; baling weight. The machine will automatically stop after reaching 95% of the set value and stabilizing for 3 seconds. (The actual weight of the packaged wheat is compared with a set value to ensure the accuracy of the finished product packaging weight).

[0152] S203b: After receiving the signal, the lower wheat bin PLC controls the lower wheat bin equipment and completes the entry into the bin by communicating with the hoist PLC and dust removal PLC through the host computer system; the hoist PLC feeds back a success signal to the host computer, triggering the dust removal PLC to perform dust removal.

[0153] The elevator PLC must start within 10 seconds. If this timeout occurs, the material feeding system PLC will pause material feeding and report a "linkage timeout" to the central control layer. Two retries are allowed (5-second interval). If the retries still fail, a manual intervention process is triggered. After the material feeding system PLC pauses material feeding, it immediately initiates the reverse emptying procedure of the conveyor chain: the bucket reverses 10° (to avoid material accumulation), and the conveyor belt runs in reverse at 50% of its rated speed for 3 seconds to send the remaining material back to the temporary storage bin. At the same time, the lower storage bin PLC records the current material position parameters (such as the conveyor belt running distance and the bucket angle) and reports them to the central control layer for archiving. When retrying to start the elevator, the conveying state is restored based on the above parameters to ensure that there is no accumulation of material during connection.

[0154] S203c: After receiving the signal, the finished goods warehouse PLC controls the storage equipment, completes the outbound process through the hoist PLC, and sends the feedback signal to the host computer system.

[0155] S3: Monitoring and Anomaly Handling: Real-time integration and display of production data, enabling multi-PLC linkage control and automatic response to abnormal situations;

[0156] In another embodiment of the present invention, step S3 further includes the following steps:

[0157] S301: The central control system PLC integrates feedback data from various PLCs and displays production parameters through a remote client.

[0158] S302: The operation panels of each PLC are displayed together via a host computer touch screen, supporting multi-PLC linkage control;

[0159] S303: Verification and correction of weighing data from the PLC of the hoist;

[0160] Verification standard: A deviation of >2% in three consecutive weighings (compared with the historical average) is considered abnormal and triggers the sensor self-test;

[0161] Corrected algorithm: In the formula, This indicates the material intake for the 5 tracks. , , , , Perform a summation operation. The temperature effect coefficient was determined experimentally. The system is currently measuring the temperature in °C. This value will change in real time depending on the environment and system operating status. The standard temperature serves as a temperature reference, used to compare the current temperature with the standard temperature in order to assess the impact of temperature changes on target parameters.

[0162] This formula combines the principles of "moving average filtering" and "temperature compensation," and references the environmental error correction model in the weighing system. The derivation process is as follows:

[0163] Step 1: Eliminate random errors by using a moving average and take the average of the first 5 track material collection amounts. ;

[0164] Step 2: Compensate for temperature effects, standard temperature Actual temperature For every 1°C deviation, the weighing value deviation is approximately (Measured experimentally) Based on the thermal expansion and contraction characteristics of wheat in the 20~30℃ range).

[0165] Final revised value: ;

[0166] Anomaly classification and handling:

[0167] Minor abnormalities: The criterion is a deviation from a single parameter (such as...). fluctuation The handling measures are local alarm and continuous monitoring, with the responsible PLC being the process execution layer PLC;

[0168] Serious abnormality: The judgment criterion is that multiple parameters exceed the limit (e.g. Disorder and The corrective action is to shut down the machine, save the current parameters, and the responsible PLC is the central control layer PLC.

[0169] Emergency anomaly: The judgment criterion is the safety threshold (e.g.) and The handling measures are to cut off the energy supply and activate the fire alarm system. The responsible PLCs are the main control PLC of the maiyao kiln and the central control layer.

[0170] Shutdown sequence: Process execution layer (stop feeding first, then stop furnace tubes) → Auxiliary control layer (stop elevator, dust collector) to avoid material accumulation.

[0171] The embodiments disclosed in this invention are preferred embodiments, but are not limited thereto. Those skilled in the art can easily understand the spirit of this invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of this invention, they are all within the protection scope of this invention.

Claims

1. A multi-PLC cooperative control based unattended system for a malting kiln, characterized by, The system comprises: a central control layer comprising a central control system PLC and an upper computer system, for global monitoring, instruction issuing and data summarizing; a process execution layer, for controlling the operation of the equipment in the whole process of the kiln, realizing automatic operation of each link of loading, batching, processing, unloading and packaging, and monitoring key parameters in real time and feeding back; an auxiliary control layer, for realizing the control of the unloading bin equipment, the dust removal process execution, the material lifting and weighing and the finished product storage management function through the cooperative communication of each subsystem PLC; the central control system PLC and the upper computer system communicate bidirectionally, support remote client data interaction, and the central control system PLC is internally provided with an instruction arbitration function module for processing multi-PLC instruction conflicts; the process execution layer comprises: a loading system PLC, for controlling the operation of the loading equipment, communicating with the automatic batching system PLC and feeding back the weight of the bin; an automatic batching system PLC, for setting the ratio according to a remote instruction, controlling the distribution mechanism and recording the weight of the track, and feeding back to the kiln master control PLC; a robot PLC, for controlling the robot to send the wheat into the kiln furnace tube, monitoring the temperature, pressure and weight of the finished product, and feeding back to the kiln master control PLC; a kiln master control PLC, for summarizing the parameters of each link, communicating with the central control system PLC and executing global instructions; an unloading system PLC, for controlling the tipping and conveying of the baked wheat to the packaging machine, recording the packaging weight and realizing weight compensation; a packaging associated PLC, for monitoring the packaging weight, cooperating with the unloading system PLC and realizing automatic shutdown in case of weight abnormality; the auxiliary control layer comprises a unloading bin PLC, a dust removal PLC, an elevator PLC and a finished product warehouse PLC; the unloading bin PLC communicates with the loading system PLC of the process execution layer, the dust removal PLC, the elevator PLC and the finished product warehouse PLC of the auxiliary control layer, and controls the action of the unloading bin equipment; the dust removal PLC communicates with the unloading bin PLC and the finished product warehouse PLC, and executes the dust removal process; the elevator PLC communicates with the unloading bin PLC and the finished product warehouse PLC, and realizes material lifting and weighing data feedback; the finished product warehouse PLC comprises a finished product warehouse process PLC, a finished product warehouse communication PLC and a finished product warehouse upper computer station, communicates with the unloading bin PLC and the elevator PLC, and controls the finished product storage; the unloading bin PLC comprises a unloading bin process PLC, a unloading bin communication PLC and a unloading bin upper computer station; the unloading bin process PLC is used for controlling the operation process of the unloading bin equipment and coordinating the orderly work of each device; the unloading bin communication PLC is used for realizing data interaction and signal transmission between the unloading bin PLC and other PLC systems; the unloading bin upper computer station is used for providing a man-machine interactive interface, realizing unloading bin equipment operation state monitoring, parameter setting and fault alarm; the dust removal PLC comprises a dust remover communication PLC, a dust removal control PLC and a dust removal upper computer communication station; the dust remover communication PLC is used for data communication with other PLC systems, obtaining operation parameters and instructions; the dust removal control PLC is used for controlling the operation of the dust remover and adjusting the working state of the dust removal equipment; The dust removal host computer communication station is used for realizing data interaction of the dust removal system and the host computer, facilitating an operator to monitor and manage the dust removal equipment; The elevator PLC includes a weighing communication PLC, a weighing calculation PLC and an upper computer elevator station; The weighing communication PLC is used for data communication with other PLCs and weighing equipment, and transmission of weighing related information; The weighing calculation PLC is used for processing weighing sensor data, calculating material weight, and data verification and correction; The upper computer elevator station is used for real-time monitoring of the running state of the elevator and the weighing data, and realizes remote operation and fault diagnosis; The use method of the system includes the following steps: S1, system initialization: configure the parameters of each PLC communication board, set the communication protocol, create function blocks and data areas, and build the basis of two-way communication between the upper and lower computers; S2, whole-process collaborative control: whole-process automation control of the wheat kiln production is performed, including the stages of feeding and batching, baking and robot operation, discharging, packaging and warehousing, to ensure accurate execution and parameter compliance of each link; S201: feeding and batching stage: control the total amount of wheat feeding and the batching of each track to ensure that the material ratio meets the production requirements; the triggering threshold of the feeding system PLC sending the "feeding complete" signal to the automatic batching system PLC; S201a: The feeding system PLC transports the wheat to the automatic batching system silo through the material taking subsystem and the metering subsystem, and calculates the total material taking amount , and sequentially feeds back to the automatic batching system PLC; in the formula, represents the material taking amount of each track, which is collected in real time by the metering subsystem, and the total material taking amount is calculated The data is used to monitor the total amount of feeding to ensure that the production requirements are met, and the formula is Based on the basic mathematical principle that "the total amount of material is equal to the sum of each partial material amount", it is applicable to total amount statistics in the scene of multi-track material taking. Referring to the general summation model in the field of industrial measurement, the material taking amounts of 10 tracks are respectively , unit: kg, total material taking amount is the cumulative value of the material taking amount of each track; S201b: The automatic batching system PLC controls the discharging mechanism to discharge the wheat to the track according to the batching ratio set by the remote client, and records the track weight ; Corresponding to the real-time weight of the wheat on different tracks respectively, for accurately controlling the material feeding amount of each track; Adjust the weight by formula , where, is the target weight, i.e. the total batch weight target of the batching stage, by comparing the difference between the actual weight of each track and the target weight, finding the track corresponding to the smallest difference, and combining the humidity correlation coefficient , the density correlation coefficient and the material quantity of each track, dynamically adjusting the batching weight of each track to ensure that the final batching total matches the target value, and feeding back the adjusted result to the silo master control PLC; Formula Based on the principle of "minimum deviation priority adjustment", reference to the deviation compensation algorithm in adaptive control, for dynamic balance of each track batching quantity and target value difference, make each track actual weight As close as possible to the target weight The distribution value defines the deviation ( ), and selects the track with the minimum deviation As the priority adjustment object, adjust the weight reference The average of the last 3 production tracks, the real-time feeding amount of the batching stage , humidity correlation coefficient And density correlation coefficient , finally through the minimum deviation matching to realize the total weight convergence, that is ; S202: baking and robot operation stage: control the baking process of wheat to ensure that the material feeding amount, temperature and pressure meet the process safety standards; S202a: The robot PLC sends the track wheat into the kiln pipe, and the real-time feeding amount deviation from the target weight , , is the real-time feeding amount of the feeding stage, is the target weight, i.e. the single feeding target of the feeding stage, if adjust the control parameters to ensure that the amount of material sent meets the process requirements; Formula Based on the definition of "absolute deviation of real-time delivery weight and target weight", reference the basic deviation model in error analysis, used to evaluate the accuracy of delivery weight, target weight The difference between the real-time delivery weight is the deviation , unit: kg, when , it is determined that the delivery weight is out of tolerance, triggering parameter adjustment; S202b: monitor the hearth temperature: determine and the ascending order, descending order rule of temperature sequence ; temperature values representing different positions in the furnace or different monitoring times, for determining the initial change trend of the temperature ascending, descending rules, for monitoring if the temperature during the roasting process varies according to the preset process curve, remote suspension of production in case of anomaly: Ramp-up period: Each temperature difference is less than or equal to 2℃, and the deviation lasts for 10s to trigger an alarm. Incubation period: , and and , is the furnace outlet temperature, the upper limit value is preset according to the wheat variety, and the default is 50℃. If , it is determined that the temperature is abnormal, the robot PLC immediately reduces the furnace tube feeding speed by 20%, and at the same time triggers special alarm; Disorder refers to any one of the following conditions: The ascending order relationship is not met for two consecutive sampling periods in the warming period . The continuous 2 sampling periods in the holding period do not satisfy the descending order relationship ; The absolute value of the temperature difference between any adjacent temperature points and for 3 s; S202c: Monitor the furnace pressure: generate pressure growth curve by linear fitting, , P is the pressure value of different monitoring points or different time in the furnace, unit: kPa, used to build pressure change model; Pressure overrun: if or , is a preset pressure growth threshold, is the maximum safe pressure value, and the furnace temperature condition in the warming-up period meets , the pressure relief logic is immediately started. If the pressure is over limit but the temperature condition of the furnace in the cooling stage meets the temperature abnormality alarm is triggered first, and the pressure is released after 5s delay. After pressure relief, the pressure is restored to less than When the pressure is less than 0.5 MPa, the PLC linkage of the robot adjusts the feeding speed of the furnace tube to maintain stable pressure and ensure that the furnace pressure is within a safe range. S203: discharging, packaging and warehousing stage: accurate discharging, packaging and warehousing management of finished wheat are performed to ensure closed-loop operation of the production process; S3, monitoring and abnormality processing: real-time integration and display of production data are realized, multi-PLC linkage control is realized, and abnormal situations are automatically handled; S301: the central control system PLC integrates the feedback data of each PLC, and displays the production parameters through a remote client; S302: each PLC operation panel is combined and displayed through the upper computer touch screen, supporting multi-PLC linkage control; S303: weighing data verification and correction of the elevator PLC; Verification standard: if the weighing deviation is greater than 2% for three times in succession, it is considered abnormal, triggering sensor self-checking; Corrected algorithm: , wherein, represents the amount of material taken from 5 tracks , , , , line sum operation, is the temperature influence coefficient calibrated by experiment, is the current actual measured temperature value of the system, in ℃, the value will change in real time with the environment or system running state, is the standard temperature, as a temperature reference benchmark, used to compare the difference between the current temperature and the standard temperature to evaluate the influence of temperature change on the target parameter; Formula Combining the principle of "sliding average filter" and "temperature compensation", and referring to the environmental error correction model in the weighing system, the derivation process is as follows: Step 1: Eliminate random error by taking the average of the last 5 track dispense amounts ; Step 2: Compensate for temperature effects, standard temperature , actual temperature For each deviation of 1 °C, the weight value deviates by ; Final correction value: .

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