A full-automatic ton-bag powder unloading control method

Abstract

The present application relates to unpacking equipment technical field, specifically to a kind of full-automatic ton bag powder discharging control method, including material transfer and pretreatment, lifting and grabbing, bag breaking and discharging and waste bag processing etc. steps.The present application is dynamically adjusted control logic according to ton bag weight-speed-offset by dynamic PID+feedforward compensation+position memory design idea;Pin shaft type weight sensor judges the state of grabbing by pressure change, avoids dust interference;Adopting disc knife high-speed rotation accurately cuts open ton bag bottom front three sides, reduces woven bag debris;Mechanical claw pierces ton bag before cutting bag, and inside and outside bag are fixed as a whole, avoid inside bag to fall off and pollute powder;Using fully-closed hydraulic packing machine to wrap waste bag, save space, no dust overflow, high working efficiency;Realize ton bag anti-deviation, lifting, grabbing, inside and outside bag fixation, cutting, stable conveying, waste bag closed packing linkage control, so that the degree of automation and intelligentization is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of unpacking equipment technology, and more specifically to a fully automatic method for controlling the feeding of powder from ton bags. Background Technology

[0002] In the petrochemical production, storage, and logistics processes, the unpacking and unloading of ton bags (powders, granular materials, etc.) constitutes a crucial link. However, this process has long relied heavily on traditional manual operation, exposing numerous structural problems. For example, manually assisted unpacking equipment only has basic cutting functions, requiring manual handling, positioning, hooking, and waste bag recycling of ton bags, resulting in high risks of mechanical injury and failing to meet the demands of large-scale, automated production. Semi-automatic unpacking systems introduce conveyor belts for ton bag transfer and use fixed triangular blades for cutting, but still have many shortcomings. In terms of cutting, the fixed triangular blades lack sharpness, easily tearing ton bags and generating a large amount of debris, affecting material quality; in terms of waste bag disposal, manual bundling and recycling are required, which is inefficient and results in spillage and environmental pollution; in terms of control, there is no precise correction and positioning mechanism, leading to low cutting accuracy due to ton bag misalignment and poor equipment coordination; and traditional microswitches (proximity switches) are prone to misjudgment and damage when encountering ton bags in dusty environments. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and to propose a fully automatic method for controlling the feeding of powder in ton bags.

[0004] The technical solution adopted by this invention to solve its technical problem is: A fully automated method for controlling the feeding of powder in ton bags includes the following steps: Material transfer and pretreatment: The ton bags are transferred to the buffer and correction conveyor belt at the inlet of the unloading device. The position, center of gravity, weight, and moving speed of the ton bags are detected. A dynamic PID + feedforward compensation algorithm is used for correction. After correction, the deviation between the center of the ton bag and the target position is ≤±15mm. The problem of inaccurate control is solved by the combined effect of high-precision weight sensing and dynamic algorithm adaptation. The synergy of the two enables active prediction and dynamic adaptation of correction, which improves the accuracy of correction. Lifting and Grabbing: The corrected ton bags are transported to the ton bag lifting module. A hydraulic lifting mechanism lifts the ton bags to the second-level platform. The second-level platform conveyor belt then delivers the ton bags to the grabbing position. The grabbing robot moves above the ton bag and confirms the grabbing status using a pin-type weight sensor between the wheel axles, triggering the gripper to close and securely grab the ton bag. The pin-type weight sensor determines the grabbing status based on pressure changes, completely avoiding dust interference and solving the problem of microswitches misjudging and being easily damaged when encountering ton bags in dusty environments. Bag breaking and unloading: The robotic arm carries the ton bag forward to the cutting position. The disc cutter rotates at high speed to precisely cut open the bottom and front three sides of the ton bag, reducing woven bag debris at the source. For ton bags with inner bags, the robotic claw punctures the ton bag before cutting, fixing the inner and outer bags together to prevent the inner bag from falling off and contaminating the powder. The robotic arm continues to move forward to the unloading funnel. The lifting mechanism vibrates at a frequency of 2Hz and an amplitude of ±10mm to ensure that the material falls completely into the funnel until the weighing sensor detects that the residual amount in the ton bag is at the preset value. The powder is sent to the dual-compartment pump sending module via an auger conveyor. The two pumps alternately feed and send the powder to the tank area. Waste bag processing: After the material is unloaded, the robotic arm moves the empty ton bags to the waste bag disposal area for release. The waste bags are then conveyed by the waste bag conveyor belt to the fully enclosed hydraulic baler for dense wrapping, saving space and preventing dust spillage, thus improving work efficiency.

[0005] Furthermore, the method employs negative pressure dust removal + pulse backflushing technology throughout the entire process, ensuring that the dust concentration in the work area is controlled at ≤5mg / m³.

[0006] Furthermore, the ton bag lifting module adopts hydraulic drive + displacement feedback + dynamic pressure regulation control. The height of the lifting platform is monitored in real time by the displacement sensor, and the main control module dynamically adjusts the hydraulic system pressure according to the weight data of the ton bag to ensure that the lifting speed is stable at 50mm / s. When the upper and lower limit sensors trigger the limit, the hydraulic power is immediately cut off and the mechanical lock is activated, and an alarm signal is sent to the main control module at the same time to avoid damage to the equipment due to overtravel.

[0007] Furthermore, after the pin-type weight sensor collects the pressure signal, it undergoes 10-times moving average filtering to eliminate noise and outputs a stable pressure value. The main control module presets a pressure threshold range according to the type of ton bag. When the detected value falls into the corresponding range, it confirms successful grabbing and triggers the bag cutting action. If the detected pressure value fails to reach the threshold or fluctuates by more than ±100N for 3 consecutive times, it is determined that the grabbing has failed. The system automatically controls the robot arm to reset and retry. If it still fails, it stops, alarms, and pushes fault information.

[0008] Furthermore, during the material transfer process, an absolute encoder and servo closed-loop control are adopted. The encoder provides real-time feedback on the trolley position, which is compared with the target position, and the servo motor speed is adjusted through a PID algorithm. Furthermore, the servo motor has a built-in temperature sensor to monitor the operating temperature in real time. When the operating temperature is greater than 40°C, the cooling fan will start automatically. When the temperature is greater than 45°C, the motor speed will be reduced by 10% until the temperature drops below 40°C.

[0009] Furthermore, the specific process for detecting the position and center of gravity of the ton bag, the weight of the ton bag, and the moving speed of the ton bag is as follows: Detecting the position and center of gravity of the ton bag: A triple grating array detection system is set up. Each grating includes 16 infrared transmitters and receivers, which are evenly arranged perpendicular to the direction of the conveyor belt. They emit 38kHz pulse-modulated infrared light to form a gridded monitoring area with 16 detection nodes in the horizontal direction and 3 detection sections in the vertical direction. When the ton bag passes through the grating group, it blocks part of the infrared beam. The receiver calculates the lateral center of gravity of the ton bag in that section based on the position coordinates of the blocked nodes. Ton bag weight detection (weighing sensor): Three triangularly arranged weighing sensors collect pressure signals in real time, and output weight data W after 10 moving average filters; Movement speed detection: It rotates synchronously with the conveyor belt motor shaft, outputting 1000 pulse signals per revolution. The PLC calculates the real-time movement speed V based on the pulse frequency, which is used to determine the priority of the correction response.

[0010] Furthermore, the corrective steps of the dynamic PID + feedforward compensation algorithm include: Data processing and operating condition classification: The PLC receives position data, reference data, and auxiliary data in real time, calculates the lateral offset ΔX=X1-X0, and classifies it as follows: slight deviation: |ΔX|≤100mm, low priority; moderate deviation: 100mm<|ΔX|≤300mm, normal priority; severe deviation: |ΔX|>300mm, emergency priority, triggering feedforward compensation + emergency acceleration. Dynamic PID parameter adaptive adjustment: The PID parameters are adjusted according to the weight W of the ton bag and the moving speed V. When W > 3 tons, the proportional coefficient Kp is increased to improve the response speed, and the derivative coefficient Kd is increased to suppress overshoot. When V > 0.3 m / s, the integral coefficient Ki is decreased to avoid integral saturation. Feedforward compensation dynamic optimization: Compensation is triggered only when there is severe deviation and high-speed operation. The compensation amount U_feedforward = maximum lateral speed × Kf, where Kf is the feedforward coefficient, with a value of 0.1-0.25. Kf is dynamically adjusted with the deviation change rate d(ΔX) / dt: d(ΔX) / dt>0, that is, when the deviation increases, Kf=0.25, maximum compensation; d(ΔX) / dt=0, that is, when the deviation is stable, Kf=0.15, medium compensation; d(ΔX) / dt<0, that is, when the deviation decreases, Kf linearly decreases to 0, and compensation stops; the final control signal U=U_pid + U_feedforward, and U≤80% of the maximum output, can prevent the ton bag from shaking. Position memory and pre-compensation: The PLC records the material type and initial offset pattern for each operation and establishes a deviation database; if the same material has the same offset pattern three times in a row, the initial target center X0'=X0+ΔX_avg×0.6 is automatically adjusted for pre-compensation, improving the correction efficiency by 30%; if the offset exceeds ±300mm five times in a row, it is determined to be an abnormal forklift placement, and an early warning is pushed to the central control module, suggesting manual intervention and adjustment.

[0011] Furthermore, the central control module includes a PLC and an industrial-grade touchscreen connected to the PLC. It adopts multi-module distributed control with an instruction execution cycle as low as 20ns, ensuring timely control response.

[0012] Technical effects of the present invention: Compared with existing technologies, the method described in this invention can correct offsets in real time, ensuring that the deviation between the center of the ton bag and the target center after correction is ≤±15mm, providing precise positioning for subsequent bag grabbing and cutting processes. Specifically, this invention, through a dynamic PID + feedforward compensation + position memory design concept, abandons traditional fixed parameter control and dynamically adjusts the control logic according to the "weight-speed-offset" of the ton bag. Simultaneously, an emergency control mechanism is added for extreme working conditions, achieving a fast yet not impulsive, stable yet not sluggish correction effect. A pin-type weight sensor determines the grabbing state through pressure changes, completely avoiding dust interference and solving the problem of microswitches misjudging and easily damaging when encountering ton bags in dusty environments. A high-speed rotating disc cutter precisely cuts open the bottom and front three sides of the ton bag, reducing woven bag debris. Before cutting, a mechanical claw punctures the ton bag to fix the inner and outer bags together, preventing the inner bag from falling off and contaminating the powder. A fully enclosed hydraulic baler is used to densely wrap the waste bags, saving space, preventing dust spillage, and improving work efficiency.

[0013] This invention achieves coordinated control of ton bag anti-deviation, lifting, gripping, inner and outer bag fixing, cutting, sealed feeding, stable conveying, and waste bag sealed packaging, which greatly improves the level of automation and intelligence. Attached Figure Description

[0014] Figure 1 This is a flowchart of the fully automatic ton bag powder feeding control method of the present invention; Figure 2 This is a schematic diagram illustrating the structural principle of the fully automatic ton bag powder feeding control device of the present invention; Figure 3 For the present invention Figure 2 The main view; Figure 4 For the present invention Figure 2 The left view.

[0015] In the diagram, 1 is the buffer correction module; 2 is the ton bag lifting module; 3 is the unpacking module; 4 is the sending module; 5 is the packing module; 6 is the waste bag processing module; and 7 is the dust removal module. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0017] Example 1: like Figure 1 As shown in the figure, this embodiment relates to a fully automatic ton bag powder feeding control method, which includes steps such as material transfer and pretreatment, lifting and gripping, bag breaking and feeding, and waste bag treatment.

[0018] Step S1, Material Transfer and Pre-processing: Forklifts transfer ton bags (such as cement, barite, and other powdered materials) from the warehouse to the buffer and correction conveyor belt at the inlet of the unloading device. The conveyor belt is 1400mm wide and 2000mm long, with a load capacity of 4 tons. The position and center of gravity of the ton bag, the weight of the ton bag, and the moving speed of the ton bag are detected. A dynamic PID + feedforward compensation algorithm is used to achieve accurate correction within a range of ±500mm. After correction, the deviation between the center of the ton bag and the target position is ≤±15mm. The problem of inaccurate control is solved by the combined effect of high-precision weight sensing and dynamic algorithm adaptation. The synergy of the two enables active prediction and dynamic adaptation of correction, improving the accuracy of correction.

[0019] During the material transfer process, an absolute encoder and servo closed-loop control are employed. The encoder provides real-time feedback on the trolley's position, which is compared with the target position. A PID algorithm is then used to adjust the servo motor speed, achieving a positioning accuracy of ≤±2mm. The servo motor has a built-in temperature sensor that monitors the operating temperature in real time. When the operating temperature exceeds 40℃, the cooling fan automatically starts; when it exceeds 45℃, the motor speed is reduced by 10% until the temperature drops below 40℃. The transfer action is linked to the status of the next workstation's equipment, initiating transfer only when the cutter is in position and the feeding hopper is open, ensuring seamless process transitions.

[0020] The specific process for detecting the position and center of gravity of the ton bag, the weight of the ton bag, and the moving speed of the ton bag is as follows: Detecting the position and center of gravity of the ton bag: A triple grating array detection system is set up. Each grating includes 16 infrared transmitters and receivers, evenly arranged perpendicular to the direction of the conveyor belt (spaced 30mm apart), emitting 38kHz pulse-modulated infrared light to form a gridded monitoring area with 16 detection nodes in the horizontal direction and 3 detection sections in the vertical direction. When the ton bag passes through the grating array, it blocks part of the infrared beam. The receiver calculates the lateral center of gravity of the ton bag in that section based on the position coordinates of the blocked nodes. After physical anti-interference (dust cover + automatic blowing), signal anti-interference (median filtering), and data fusion (cross-verification of the three centers of gravity), the detection accuracy reaches 99.2%. Ton bag weight detection (weighing sensor): Three triangularly arranged weighing sensors collect pressure signals in real time. After 10 moving average filtering, the weight data W (accuracy ±0.5%) is output, providing working condition basis for PID parameter adjustment; Movement speed detection (absolute encoder): It rotates synchronously with the conveyor belt motor shaft and outputs 1000 pulse signals per revolution. The PLC calculates the real-time movement speed V (update frequency 500Hz) based on the pulse frequency, which is used to determine the priority of the correction response.

[0021] The corrective steps of the dynamic PID+feedforward compensation algorithm include: Data processing and operating condition classification: The PLC receives position data, reference data, and auxiliary data in real time, calculates the lateral offset ΔX=X1-X0, and classifies it as follows: slight deviation: |ΔX|≤100mm, low priority; moderate deviation: 100mm<|ΔX|≤300mm, normal priority; severe deviation: |ΔX|>300mm, emergency priority, triggering feedforward compensation + emergency acceleration. Dynamic PID parameter adaptive adjustment: The PID parameters are adjusted according to the weight W of the ton bag and the moving speed V. When W > 3 tons, the proportional coefficient Kp is increased (0.8→1.2) to improve the response speed, and the derivative coefficient Kd is increased (0.1→0.3) to suppress overshoot. When V > 0.3 m / s, the integral coefficient Ki is decreased (0.05→0.02) to avoid integral saturation. Feedforward compensation dynamic optimization: Compensation is triggered only when there is severe deviation and high-speed operation. The compensation amount U_feedforward = maximum lateral speed × Kf, where Kf is the feedforward coefficient, with a value of 0.1-0.25. Kf is dynamically adjusted with the deviation change rate d(ΔX) / dt: d(ΔX) / dt>0, that is, when the deviation increases, Kf=0.25, maximum compensation; d(ΔX) / dt=0, that is, when the deviation is stable, Kf=0.15, medium compensation; d(ΔX) / dt<0, that is, when the deviation decreases, Kf linearly decreases to 0, and compensation stops; the final control signal U=U_pid + U_feedforward, and U≤80% of the maximum output, can prevent the ton bag from shaking. Position memory and pre-compensation: The PLC records the material type and initial offset pattern for each operation, establishing a deviation database of 1000 entries; if the same material exhibits the same offset pattern three times consecutively, the initial target center X0'=X0+ΔX_avg×0.6 is automatically adjusted (pre-compensating 60% of historical deviations) to perform pre-compensation, improving correction efficiency by 30%; if the offset exceeds ±300mm five times consecutively, it is determined to be an abnormal forklift placement, and an early warning is pushed to the central control module, suggesting manual intervention and adjustment.

[0022] Specifically, in the data processing and operating condition classification steps described in this embodiment, the PLC receives the following three types of data in real time: Location data (X1): The lateral center of gravity coordinates of the ton bag obtained by the triple grating array detection system; each grating includes 16 infrared transmitters and receivers, evenly arranged perpendicular to the conveyor belt running direction (spaced 30mm apart), forming a gridded monitoring area with 16 nodes laterally and 3 cross sections longitudinally; when the ton bag passes through, the receiver calculates the lateral center of gravity of each cross section based on the coordinates of the obstructed nodes, and outputs X1 after physical anti-interference (dust cover + automatic blowing), signal anti-interference (median filtering) and data fusion (cross-verification of the three centers of gravity), with a detection accuracy of 99.2%; Reference data (X0): The preset horizontal center line of the target ton bag, calibrated according to the installation position of the grating array (usually set to the middle value of the horizontal detection node), is stored in the PLC in advance; Auxiliary data includes the weight data W of the ton bag and the moving speed data V. The weight data W is collected in real time by three weighing sensors arranged in a triangle, and the pressure signal is output after 10 moving averages filtering with an accuracy of ±0.5%. The moving speed data V is collected by an absolute encoder that rotates synchronously with the conveyor belt motor shaft, outputting 1000 pulse signals per revolution. The PLC calculates the real-time speed V at a refresh frequency of 500Hz.

[0023] The PLC calculates the lateral offset ΔX = X1–X0 based on the position data X1 and the reference data X0, and determines the working condition level according to the following rules in conjunction with auxiliary data.

[0024] Step S2, Lifting and Grabbing: The corrected ton bag is conveyed to the ton bag lifting module (platform 1400×1400mm, lifting height 4000mm, lifting speed 1m / s). Through the hydraulic lifting mechanism, the ton bag is lifted to the second-level platform. The second-level platform conveyor belt sends the ton bag to the waiting grab position. The grabbing robot moves above the ton bag and confirms the grabbing status through the pin-type weight sensor between the wheel axle (pressure sensing threshold ≥500N). It triggers the gripper to close with a 3000N clamping force to achieve a stable grabbing of the ton bag. The pin-type weight sensor detects pressure changes, fundamentally avoiding dust interference and mechanical collision damage, and providing accurate start signal support for quantitative feeding. Preferably, the ton bag lifting module adopts hydraulic drive + displacement feedback + dynamic pressure regulation control. The displacement sensor monitors the height of the lifting platform in real time, and the main control module dynamically adjusts the hydraulic system pressure according to the weight data of the ton bag to ensure that the lifting speed is stable at 50mm / s. When the upper and lower limit sensors trigger the limit, the hydraulic power is immediately cut off and the mechanical lock is activated, and an alarm signal is sent to the main control module at the same time to avoid damage to the equipment due to overtravel.

[0025] Specifically, after the pin-type weight sensor collects the pressure signal, it undergoes a 10-times moving average filtering process to eliminate noise and outputs a stable pressure value. The central control module presets a pressure threshold range based on the type of ton bag. When the detected value falls within the corresponding range, it confirms successful gripping and triggers the bag-cutting action. If the pressure value fails to reach the threshold or fluctuates beyond ±100N for three consecutive tests, the gripping is deemed a failure, and the system automatically controls the robotic arm to reset and retry. If the failure persists, the system stops, alarms are triggered, and fault information is pushed out. Specifically, the pin-type weight sensor is installed in the upper middle part of the axle, using pressure changes to determine the gripping status and avoid dust interference. When the bag is not in contact with the gripper, the pin-type weight sensor bears the entire weight of the gripper (stabilizing at around 1500N). After contacting and gripping the bag, the supporting reaction force of the bag reduces the pressure on the pin-type weight sensor (pressure drops to 700-1000N for lightly loaded bags and to 300-700N for heavily loaded bags). The system accurately confirms the "contact-grip" state through the pressure change rate (dP / dt≥200N / s). This design completely avoids dust interference with sensing, and the current sensing reliability is improved to 99.5%, providing a reliable signal for the precise initiation of quantitative feeding.

[0026] Step S3, Bag Breaking and Discharge: The robotic arm carries the ton bag forward to the cutting position. The carbide disc cutter rotates at high speed, precisely cutting open the bottom and front three sides of the ton bag, reducing woven bag debris from the source (improving cut neatness and reducing debris). For ton bags with inner bags, the robotic claw punctures the ton bag before cutting, fixing the inner and outer bags together to prevent the inner bag from falling off and contaminating the powder. The robotic arm continues to move forward to the discharge funnel. The lifting mechanism vibrates at a frequency of 2Hz and an amplitude of ±10mm to ensure that the material falls completely into the funnel until the weighing sensor detects that the residual amount in the ton bag is less than 5kg (residual rate ≤0.1%). The powder is sent to the dual-compartment pump delivery module (single tank volume 3m³, delivery speed 1.5m³ / min) via an auger conveyor. The two pumps alternately feed and deliver the powder at a working pressure of 0.3MPa, achieving stable delivery of the powder to the tank area.

[0027] Step S4, Waste Bag Processing: After the material is unloaded, the robotic arm moves the empty ton bags to the waste bag disposal area for release. The bags are then conveyed via a 1m wide and 18m long waste bag conveyor belt (5.5kw, operating speed 10m / min) to a fully enclosed hydraulic baler (baling thrust 160T, main power 30kw). This machine compresses 300 waste bags into dense packages of 0.9×0.9×0.9m in one go (compression ratio ≥100:1), saving 90% of storage space and eliminating dust spillage.

[0028] The method described in this embodiment relies entirely on a closed dust removal system (7.5kw fan, dust removal air volume of 2000m³ / minute, 20 self-cleaning filter elements), and adopts negative pressure dust removal + pulse back-flushing technology to control the dust concentration in the working area to ≤5mg / m³.

[0029] The central control module described in this embodiment includes a Siemens S7-1500 series PLC and an industrial-grade touchscreen. The PLC synchronizes its clock with the central control module via the IEEE 1588 protocol (error ≤ 1ms) to ensure that the timing of the correction action matches the subsequent packet grabbing and cutting actions, avoiding delays in process connections. It communicates with the servo driver and sensors via the Profinet protocol (command issuance delay ≤ 200ms), employing a "command + feedback" dual-link mechanism. After the servo motor completes its action, it immediately sends back a confirmation signal. If no feedback is received, the command is resent within 50ms. If the resentment fails three times, redundant control is activated.

[0030] In this embodiment, redundant control is implemented: the dual servo motors adopt a "master-slave" control mode and drive synchronously during normal operation; when the master motor fails (such as encoder signal loss or abnormal current), the slave motor automatically switches and increases its output power to 120% to ensure that the correction action is not interrupted, and at the same time, the faulty motor information is recorded for subsequent maintenance.

[0031] In this embodiment, the actuator's action is controlled in a closed loop: after the PLC issues a lateral movement command, the coordinates of the ton bag's center of gravity are fed back in real time through a grating array, and the motor speed and direction are dynamically adjusted until ΔX≤±15mm, at which point the correction action stops. The entire process takes ≤1.2 seconds, which is 52% shorter than the traditional solution.

[0032] The actuator in this embodiment features load self-adaptation: based on the weight of the ton bag fed back by the weighing sensor, the output torque of the servo motor is adjusted—when W > 3 tons, the torque is increased to 110% of the rated value to ensure rapid correction under heavy load; when W < 2 tons, the torque is reduced to 80% of the rated value to avoid the ton bag slipping due to excessively rapid correction under light load.

[0033] This embodiment achieves dynamic adaptive control and highly stable execution through the above closed-loop control process. After 2000 full-load tests, the correction success rate is 99.9%, and it runs continuously for 500 hours without any lag.

[0034] This invention significantly improves the accuracy of deviation correction, solving the pain points of traditional devices such as "large deviations and frequent misadjustments." Furthermore, through the synergy of weight sensing and sensor systems, the module possesses strong adaptability to various working conditions, making it better suited for complex environments with varying bag weights and fluctuating environments. The invention also seals the waste bags, preventing spillage and pollution. This invention constructs a high-precision weight sensing + control adaptation system. A pin-type weight sensor at the wheel axle collects real-time bag weight data (indirectly acquired, based on the difference between the gripper's own weight and the pressure change after contact). Although not a direct weighing, it provides a basic weight reference for subsequent quantitative feeding (e.g., determining whether the bag meets the preset loading range). Precise weight sensing can pre-screen abnormally heavy tonnes (such as those with leakage or overweight during sea transport), preventing measurement deviations caused by these abnormal tonnes entering the subsequent quantitative feeding stage. Simultaneously, weight data can be fed back to the central control module, which automatically adjusts the quantitative feeding parameters based on the weight level, providing a basis for adapting the quantitative feeding speed and flow control (e.g., slowing down the feeding speed for heavy-load tonnes) to ensure quantitative accuracy. This invention can be widely applied to bulk material feeding scenarios in petrochemical, port storage, and grain processing industries.

[0035] This embodiment can also be linked with an intelligent automated warehouse. After receiving production orders, the intelligent automated warehouse accurately retrieves the corresponding ton bags via a four-way vehicle / stall crane, and delivers the ton bags point-to-point to the entrances of each unpacking machine via the north wall conveyor belt. At the same time, it supplies materials to the backup manual unpacking line, realizing seamless connection of material flow between the automated warehouse and the unpacking line. The entire process can form a data closed loop: the information flow of the automated warehouse, unpacking machine, tank area, air compressor station, and waste bag packaging station is connected through the SCADA system, realizing unmanned linkage of the entire process from order placement to material outbound, bag breaking and unloading, powder entering the tank, and waste bag recycling. It also supports production data traceability and remote operation and maintenance.

[0036] Example 2: like Figure 2-4 As shown in the figure, this embodiment relates to a fully automatic ton bag powder feeding control device, which includes a buffer correction module 1, a ton bag lifting module 2, a unpacking module 3, a sending module 4, a packaging module 5, a waste bag processing module 6, a dust removal module 7, and a central control module that are linked in sequence. The modules work together to achieve fully automated operation throughout the entire process.

[0037] The buffer correction module 1, as a key pre-mounted module of the fully automatic feeding device, achieves its dual objectives of "high precision + high stability" primarily through the synergy of a multi-dimensional sensor monitoring system and precise weight sensing capabilities. It is used to detect the position and center of gravity of the ton bag, the weight of the ton bag, and the moving speed of the ton bag, and uses a dynamic PID + feedforward compensation algorithm for precise correction. High-precision weight sensing and dynamic algorithm dynamic control provide "load adaptation basis", jointly solving the pain points of traditional devices such as "many misjudgments, slow response, and decreased accuracy", and supporting continuous and efficient operation throughout the entire process.

[0038] The central control module constructs a fully automated control system: 1. Precise and collaborative control throughout the entire process Core hardware: It adopts Siemens S7-1500 series PLC, paired with industrial-grade touch screen (IP65 protection), supports multi-module distributed control, and has an instruction execution cycle as low as 20ns, ensuring timely control response.

[0039] Timing synchronization control: Through the IEEE 1588 precise clock synchronization protocol, the clocks of all modules, including the buffer correction module 1, ton bag lifting module 2, unpacking module 3, sending module 4, packing module 5, waste bag processing module 6, and dust removal module 7, are synchronized with an error of ≤1ms. A "process linkage timing table" is established. For example, after the correction module completes positioning, the bag grabbing action is triggered within 200ms. After successful bag grabbing, the cutter is started within 300ms. After the cutter runs for 1 second, the dust removal fan is started synchronously. There is no waiting connection throughout the process, and the processing cycle of a single ton bag is shortened to 2 minutes.

[0040] Material adaptation control: Preset process parameter templates for 5 types of materials (fine powder / granular material / sticky material / moisture-absorbing material / heavy-load material), including parameters such as gripping force, cutter speed, feeding speed, and dust removal air volume; supports two triggering methods: one is manual one-click switching via touch screen, and the other is automatic identification of material type by laser particle size analyzer at the feeding port, with the central control automatically matching the optimal template without manual intervention.

[0041] 2. Data-driven intelligent control Multi-dimensional data acquisition: It connects to more than 20 types of sensors via 485 bus and Profinet protocol to collect more than 200 key data in real time, including equipment operating parameters (motor current, speed, pressure), material parameters (ton bag weight, discharge flow rate, dust concentration), and environmental parameters (temperature, humidity). The data update frequency is 500Hz, local storage supports 1 year of traceability, and it is also uploaded to the factory cloud platform via MQTT protocol.

[0042] In-depth data application and exploration: Trend analysis and anomaly warning: By analyzing data trends through AI algorithms, such as if the current of the cutter motor increases by 5% for three consecutive operations, it is determined that the cutter is worn and a replacement reminder is pushed in advance; when the dust concentration is >3mg / m³, the frequency of the dust removal fan is automatically increased by 20%, and when it is >4.5mg / m³, an interlock shutdown is triggered to prevent excessive emissions.

[0043] Process parameter self-optimization: Based on historical data, a PID optimization model is trained to automatically adjust key parameters, such as adjusting the gripping force of the bag according to the weight fluctuation of the ton bag, and adjusting the auger speed according to the change of the material flow rate, so that the unpacking efficiency is improved by 8%-12% compared with the initial setting, and the material metering error is ≤±0.3%.

[0044] 3. Three-level intelligent pre-maintenance control Level 1 self-test control upon startup: Before the equipment starts, it automatically performs a three-in-one check of "sensor calibration - actuator test - communication link detection"—sending a standard load signal to the weighing sensor to verify accuracy (alarm when deviation > 0.5%); controlling the cutting cylinder to complete 3 full strokes to detect whether there is any jamming; scanning the industrial Ethernet device list to confirm that no nodes are missing (if any are missing, the specific module is located). Only after all checks are passed can the equipment be started and operated.

[0045] Level 2 Operation Monitoring and Control: Real-time acquisition of key component status; monitoring of dust collector fan bearing wear via vibration sensor (accuracy 0.1m / s²) (warning when vibration value > 2.8m / s²); analysis of screw motor stall risk via current transformer (protection triggered if current exceeds rated value by 1.2 times for 3 seconds, immediately stopping the machine and reversing to clear blockage); monitoring of dust collector filter status via filter differential pressure sensor (pulse backflushing cleaning initiated when differential pressure > 2kPa).

[0046] Level 3 predictive maintenance control: Based on equipment operation data and component lifespan models (such as "cutter lifespan = 1500 cuts ± 10%" and "filter lifespan = 800 hours of operation"), the system automatically calculates the remaining lifespan of components and generates maintenance reminders 3-5 days in advance (such as "cutter lifespan approximately 200 cuts, recommended replacement within 5 days"), and pushes them to maintenance personnel via SMS / APP; at the same time, it records maintenance records to form a "maintenance-lifespan" related database to continuously optimize the maintenance cycle.

[0047] The cache correction module 1, ton bag lifting module 2, unpacking module 3, sending module 4, packaging module 5, waste bag processing module 6, and dust removal module 7 are integrated under the unified control of the central control module to ensure process continuity. Combined with a three-level pre-maintenance control system, the annual downtime due to failure is controlled to within 16 hours, and the operation and maintenance costs are reduced by more than 30%. It can be widely used in bulk material unloading scenarios such as petrochemical, port storage, and grain processing, and is especially suitable for complex scenarios with multiple constraints such as production capacity, environmental protection, and safety, such as CNOOC Hainan Terminal.

[0048] The above-described specific embodiments are merely specific examples of the present invention. The patent protection scope of the present invention includes, but is not limited to, the above-described specific embodiments. Any appropriate changes or modifications made by a person skilled in the art that conform to the claims of the present invention should fall within the patent protection scope of the present invention.

Claims

1. A fully automatic method for controlling the feeding of powder in ton bags, characterized in that, Includes the following steps: Material transfer and pretreatment: The ton bags are transferred to the buffer correction conveyor belt at the inlet of the feeding device. The position and center of gravity of the ton bags, the weight of the ton bags, and the moving speed of the ton bags are detected. Dynamic PID + feedforward compensation algorithm is used for correction. Lifting and Grabbing: The ton bag that has completed the correction is transported to the ton bag lifting module. The hydraulic lifting mechanism lifts the ton bag to the second-level platform. The second-level platform conveyor belt sends the ton bag to the waiting grab position. The grabbing robot moves above the ton bag and confirms the grabbing status through the pin-type weight sensor between the wheel axle, triggering the gripper to close and realize the stable grabbing of the ton bag. Bag breaking and unloading: The robotic arm carries the ton bag forward to the cutting position, where the disc cutter rotates to cut open the bottom and front three sides of the ton bag; for ton bags with inner bags, the robotic claw punctures the ton bag before cutting, fixing the inner and outer bags together; the robotic arm continues to move forward to the unloading funnel, where the lifting mechanism vibrates at a frequency of 2Hz and an amplitude of ±10mm to ensure that the material falls completely into the funnel until the weighing sensor detects that the residual amount in the ton bag has reached the preset value; the powder is fed into the dual-compartment pump sending module via an auger conveyor, and the two compartment pumps alternately feed and send the powder to achieve stable delivery of the powder to the tank area; Waste bag processing: After the material is unloaded, the robot arm moves the empty ton bags to the waste bag disposal area for release, and then the waste bags are conveyed to the fully enclosed hydraulic baler for dense wrapping via the waste bag conveyor belt.

2. The fully automatic ton bag powder feeding control method according to claim 1, characterized in that, The method employs negative pressure dust removal and pulse backflushing technology throughout the entire process, ensuring that the dust concentration in the work area is controlled at ≤5mg / m³.

3. The fully automatic ton bag powder feeding control method according to claim 1, characterized in that, The ton bag lifting module monitors the height of the lifting platform in real time through a displacement sensor. The main control module dynamically adjusts the hydraulic system pressure based on the weight data of the ton bag to ensure that the lifting speed is stable at 50mm / s. When the upper and lower limit sensors trigger the limit, the hydraulic power is immediately cut off and the mechanical lock is activated, and an alarm signal is sent to the main control module at the same time.

4. The fully automatic ton bag powder feeding control method according to claim 1, characterized in that, After the pin-type weight sensor collects the pressure signal, it is filtered by 10 moving averages to eliminate noise and output a stable pressure value. The main control module presets a pressure threshold range according to the type of ton bag. When the detected value falls into the corresponding range, it confirms successful grabbing and triggers the bag cutting action. If the detected pressure value fails to reach the threshold or fluctuates more than ±100N for 3 consecutive times, it is determined that the grabbing has failed. The system automatically controls the robot arm to reset and retry. If it still fails, it will stop the machine, alarm, and push fault information.

5. The fully automatic ton bag powder feeding control method according to claim 1, characterized in that, During the material transfer process, the encoder provides real-time feedback on the trolley's position, which is then compared with the target position using a PID algorithm to adjust the servo motor speed.

6. The fully automatic ton bag powder feeding control method according to claim 5, characterized in that, The servo motor has a built-in temperature sensor that monitors the operating temperature in real time. When the operating temperature is greater than 40°C, the cooling fan will start automatically. When the temperature is greater than 45°C, the motor speed will be reduced by 10% until the temperature drops below 40°C.

7. The fully automatic ton bag powder feeding control method according to claim 1, characterized in that, The specific process for detecting the position and center of gravity of the ton bag, the weight of the ton bag, and the moving speed of the ton bag is as follows: Detecting the position and center of gravity of the ton bag: A triple grating array detection system is set up. Each grating includes 16 infrared transmitters and receivers, which are evenly arranged perpendicular to the direction of the conveyor belt. They emit 38kHz pulse-modulated infrared light to form a gridded monitoring area with 16 detection nodes in the horizontal direction and 3 detection sections in the vertical direction. When the ton bag passes through the grating group, it blocks part of the infrared beam. The receiver calculates the lateral center of gravity of the ton bag in that section based on the position coordinates of the blocked nodes. Ton bag weight detection: Three triangularly arranged weighing sensors collect pressure signals in real time, and after 10 moving average filtering, output weight data W; Movement speed detection: It rotates synchronously with the conveyor belt motor shaft, outputting 1000 pulse signals per revolution. The PLC calculates the real-time movement speed V based on the pulse frequency, which is used to determine the priority of the correction response.

8. The fully automatic ton bag powder feeding control method according to claim 1, characterized in that, The corrective steps of the dynamic PID+feedforward compensation algorithm include: Data processing and operating condition classification: The PLC receives position data, reference data, and auxiliary data in real time, calculates the lateral offset ΔX=X1-X0, and classifies it as follows: slight deviation: |ΔX|≤100mm, low priority; moderate deviation: 100mm<|ΔX|≤300mm, normal priority; severe deviation: |ΔX|>300mm, emergency priority, triggering feedforward compensation + emergency acceleration. Dynamic PID parameter adaptive adjustment: The PID parameters are adjusted according to the weight W of the ton bag and the moving speed V. When W > 3 tons, the proportional coefficient Kp is increased, and the derivative coefficient Kd is increased at the same time to suppress overshoot; when V > 0.3 m / s, the integral coefficient Ki is decreased. Feedforward compensation dynamic optimization: Compensation is triggered only when there is severe deviation and high-speed operation. The compensation amount U_feedforward = maximum lateral speed × Kf, where Kf is the feedforward coefficient, and Kf is dynamically adjusted with the deviation rate d(ΔX) / dt: d(ΔX) / dt>0, that is, Kf=0.25 when the deviation increases, maximum compensation; d(ΔX) / dt=0, that is, Kf=0.15 when the deviation is stable, medium compensation; d(ΔX) / dt<0, that is, Kf decreases linearly to 0 when the deviation decreases, compensation stops; the final control signal U=U_pid + U_feedforward, and U≤80% of the maximum output; Position memory and pre-compensation: The PLC records the material type and initial offset pattern for each operation and establishes a deviation database; if the same material has the same offset pattern three times in a row, the initial target center X0'=X0+ΔX_avg×0.6 is automatically adjusted for pre-compensation; if the offset exceeds ±300mm five times in a row, it is determined to be an abnormal forklift placement and an early warning is pushed to the central control module.

9. The fully automatic ton bag powder feeding control method according to claim 1, characterized in that, The central control module includes a PLC and an industrial-grade touchscreen connected to the PLC.

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