Automatic material stacking device and method thereof

Abstract

The present application relates to the field of automated logistics equipment, in particular to a kind of material automated stacking device and method thereof;Including: the construction of the multi-field coupling end effector containing particle block layer and reverse prestressed air chamber;Flexible covering amorphous material is utilized by pneumatic artificial muscle;Rigid casting effect is generated by vacuumizing inner cavity and inflating outer cavity coupling, and the form of material is locked;High-speed trajectory conveying is executed, and release is completed based on the pulse airflow of pneumatic impedance feedback adjustment.This application effectively eliminates the internal rheology of soft packaging material, crosses uneven area through stiffness compensation mechanism, and solves the problem of sliding and stacking collapse caused by center of gravity change.

Description

Technical Field

[0001] This invention relates to the field of automated logistics equipment, specifically to an automated material stacking device and method. Background Technology

[0002] With the rapid development of logistics automation technology, automated stacking devices have been widely used in stacking operations for irregularly shaped flexible packaging materials such as powder bags and feed packages. However, due to the significant morphological rheological properties and physical uncertainties of these materials, traditional stacking methods and devices face the following problems in actual operations:

[0003] During high-speed transport, irregularly shaped flexible packaging materials are subject to displacement due to the combined effects of inertia and gravity, resulting in uncontrollable rheological changes in the overall shape of the material. This phenomenon causes a severe shift in the center of gravity, making it easy for the material to slip off the end effector or experience violent shaking when the robotic arm performs high-acceleration, variable-trajectory conveying, which seriously affects the stability and positioning accuracy of the conveying process.

[0004] During the material release and stacking stages, existing technologies often employ a uniform unloading mode, making it difficult to identify and address the complex micro-topography of the stack surface. When the bottom stack surface is uneven, loose, or has unevenly distributed support, existing technologies cannot detect the support status of the contact interface, causing the material to tilt, collapse, or be squeezed and displaced upon release due to loss of support. This negative effect, stemming from the inability to avoid contact surface defects, directly limits the density and verticality of the stack, resulting in loose interlayer bonding and difficulty in achieving high-stability stacking in unstructured environments.

[0005] Traditional gripping mechanisms often employ rigid wrapping, which struggles to achieve a complete fit when dealing with flexible packaging materials that have irregular wrinkles on their surface. This not only leads to uneven gripping force distribution, easily damaging the outer packaging, but also generates excessive centripetal force during vacuuming or pressurization, causing the material to deform under pressure and further exacerbating positioning errors. Therefore, existing technologies are insufficient to meet the reliability and operational efficiency requirements of modern high-speed automation when handling flexible packaging materials with rheological properties.

[0006] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to provide an automated material stacking device and method to solve the problems mentioned in the background art. Specifically, the technical solution of this invention is as follows:

[0008] An automated material stacking method includes:

[0009] S1. A pneumatic control system and a robotic arm system are set up. A multi-field coupled end effector is installed at the end of the robotic arm system. The multi-field coupled end effector includes, from the inside to the outside, a particle blocking layer cavity filled with non-blocking filling particles, a reverse prestressed air chamber, and a pneumatic artificial muscle skeleton.

[0010] S2. Control the robotic arm system to the gripping position, maintain the normal pressure in the inner cavity of the particle blockage layer and the outer cavity of the reverse prestressed air chamber, and use the pneumatic artificial muscle skeleton to drive the multi-field coupled end effector to cover the amorphous soft packaging material.

[0011] S3. Start the pneumatic control system to evacuate the inner cavity of the particle blockage layer to -0.08MPa~-0.04MPa, and at the same time inflate the outer cavity of the reverse prestressing gas chamber. The inflation pressure is positively correlated with the volume shrinkage of the inner cavity of the particle blockage layer.

[0012] S4. Drive the robotic arm system to transport materials to the top of the stacking point at high speed by changing the trajectory.

[0013] S5. Perform a release operation based on aerodynamic impedance feedback, introduce high-frequency pulsed airflow into the cavity of the particle blockage layer and detect the back pressure change rate, and adjust the vacuum level maintenance threshold and pressure relief strategy accordingly to complete the stacking.

[0014] Preferably, step S5 is preceded by:

[0015] The pre-built flow resistance-deformation-stiffness mapping model is invoked, and the local support stiffness of the stacked surface and the real-time impedance characteristics at release are used as the correlation objects to calculate the compensation stiffness value required to maintain the material shape.

[0016] Preferably, during the calculation process of calling the flow resistance-deformation-stiffness mapping model:

[0017] In the flow resistance-deformation-stiffness mapping model, the compensation stiffness value is a function of the pulse airflow pressure change rate and flow fluctuation, and the aerodynamic impedance characteristics include the pulse airflow pressure change rate.

[0018] Preferably, step S5 includes:

[0019] The multi-field coupled end effector is controlled to press down and contact the surface of the lower stack body;

[0020] A high-frequency pulsed airflow with a frequency of 20Hz to 50Hz is introduced into the inner cavity of the particle blockage layer; at this time, the peak pressure of the pulsed airflow needs to be set higher than the current absolute pressure of the inner cavity to ensure that the airflow can effectively enter and generate a detectable back pressure disturbance.

[0021] If the rate of change of the airflow back pressure is detected to be lower than the preset flatness threshold, the vacuum degree of the cavity of the particle blockage layer is maintained in the semi-rigid threshold range of -0.03MPa to -0.01MPa, and the vacuum degree is linearly reduced until it returns to zero during the lifting process of the robotic arm system.

[0022] If the rate of change of the airflow back pressure is detected to be higher than or equal to the smoothness threshold, the cavity of the particle blockage layer is directly restored to normal pressure.

[0023] Preferably, in step S1, the non-blocking filling particles are a mixture of silicone particles and polystyrene microspheres, and the lining material of the inner cavity of the particle blocking layer is silicone rubber with low elastic modulus and high tear strength.

[0024] Preferably, in step S3, the inflation volume expansion of the outer cavity of the reverse prestressed gas chamber is equal to the volume contraction of the inner cavity of the particle blockage layer due to vacuuming, so as to offset the radial deformation caused by the inner cavity contraction, and so that the total outer diameter of the multi-field coupled end effector remains dynamically stable on a macroscopic level.

[0025] Preferably, in step S1, the pneumatic artificial muscle skeleton is woven from several pneumatic muscle fibers, and the pneumatic muscle fibers surround the outer cavity of the reverse prestressed air chamber in a cage-like structure.

[0026] Preferably, in step S1, the volume ratio of silica gel particles to polystyrene microspheres in the non-blocking filling particles is 3:1 to 5:1, and the average diameter of the particles is 0.5 mm to 2.0 mm.

[0027] An automated material stacking device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. When executed by the processor, the computer program implements the aforementioned automated material stacking method. The device's specific structure includes:

[0028] robotic arm system;

[0029] A multi-field coupled end effector is disposed at the end of the robotic arm system; wherein, the multi-field coupled end effector includes a pneumatic artificial muscle skeleton for providing macroscopic envelope force, a reverse prestressed air chamber located inside the pneumatic artificial muscle skeleton, and a particle blocking layer cavity located inside the reverse prestressed air chamber.

[0030] The pneumatic control system is connected to the pneumatic artificial muscle skeleton, the outer cavity of the reverse prestressed air chamber, and the inner cavity of the particle blockage layer, respectively; wherein, the pneumatic control system is used to provide positive pressure airflow and negative pressure vacuum.

[0031] Preferably, the inlet bypass detection end of the particle blockage layer cavity is equipped with a high-frequency solenoid valve, a micro-flow sensor, and a micro-differential pressure sensor to accurately collect the airflow back pressure signal during pulse intervals or in a steady flow state.

[0032] Compared with the prior art, the present invention has the following improvements and advantages:

[0033] 1. This rigid molding effect eliminates the internal morphological changes of the material, ensuring the consistency of the center of gravity. This allows the robotic arm to perform variable trajectory conveying at high acceleration, significantly improving work efficiency and preventing material slippage. The system uses a flow resistance-deformation-stiffness mapping model to calculate the compensation stiffness value required to maintain the material's shape in real time. The calculation logic of the compensation stiffness value reflects the physical equilibrium relationship. This mechanism allows the device to cross uneven areas below like a bridge, providing a temporary flat base for the material. This effectively avoids the collapse of the stack caused by the looseness of the lower stack, ensuring high-density and stable stacking.

[0034] 2. By ensuring that the expansion of the air volume in the outer cavity of the reverse prestressed gas chamber equals the contraction of the air volume in the inner cavity of the particle blockage layer, an antagonistic volume change balance is achieved. This design ensures that the geometric center of the end effector always coincides with the calibration center of the robotic arm, avoiding centripetal force-induced material compression damage and maintaining extremely high trajectory accuracy;

[0035] 3. The macroscopic enveloping force provided by the pneumatic artificial muscle skeleton, combined with the fine shaping ability of the particle layer, constitutes a mechanical system that is flexible on the outside and rigid on the inside. The silicone particles and polystyrene microspheres are mixed in a certain volume ratio, which not only ensures the shear modulus after rigidification, but also ensures the flow compliance under normal pressure by utilizing the lubrication effect of the microspheres, thus achieving complete adhesion to the tiny wrinkles on the surface of the material. Attached Figure Description

[0036] The present invention will be further explained below with reference to the accompanying drawings and embodiments:

[0037] Figure 1 This is a schematic diagram of the overall external structure of the device;

[0038] Figure 2 This is a schematic diagram of a multi-field coupled end effector;

[0039] Figure 3 This is a schematic diagram of the pneumatic control system.

[0040] Figure 4 This is a schematic diagram of the process flow of the method of the present invention.

[0041] In the diagram: 100, robotic arm system; 200, multi-field coupled end effector; 210, inner cavity of particle blockage layer; 212, non-blocking filling particles; 220, outer cavity of reverse prestressed air chamber; 230, pneumatic artificial muscle skeleton; 231, pneumatic muscle fiber; 300, pneumatic control system; 310, high-frequency solenoid valve; 320, differential pressure sensor; 400, irregular flexible packaging material; 500, lower stack. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0043] Example 1:

[0044] Please see Figures 1-4 This invention provides an automated material stacking method, comprising:

[0045] S1. A pneumatic control system 300 and a robotic arm system 100 are set up. A multi-field coupled end effector 200 is installed at the end of the robotic arm system 100. The multi-field coupled end effector 200 includes, from the inside to the outside: a particle blocking layer cavity 210 filled with non-blocking filling particles 212, a reverse prestressed air chamber 220, and a pneumatic artificial muscle skeleton 230.

[0046] S2. Control the robotic arm system 100 to the gripping position, maintain the normal pressure of the inner cavity 210 of the particle blockage layer and the outer cavity 220 of the reverse prestressed air chamber, and use the pneumatic artificial muscle skeleton 230 to drive the multi-field coupled end effector 200 to cover the amorphous soft packaging material 400.

[0047] S3. Start the pneumatic control system 300 to evacuate the inner cavity 210 of the particle blockage layer to -0.08MPa~-0.04MPa, and at the same time inflate the outer cavity 220 of the reverse prestressed gas chamber. The inflation pressure is positively correlated with the volume shrinkage of the inner cavity 210 of the particle blockage layer.

[0048] S4. Drive the robotic arm system to transport materials to the top of the stacking point at high speed with variable trajectory.

[0049] S5. Perform a release operation based on aerodynamic impedance feedback, introduce high-frequency pulsed airflow into the inner cavity 210 of the particle blockage layer and detect the back pressure change rate, and adjust the vacuum level maintenance threshold and pressure relief strategy accordingly to complete the stacking.

[0050] This is achieved by adjusting the duty cycle of the high-frequency solenoid valve 310;

[0051] This embodiment aims to solve the problems of morphological rheology and center of gravity drift of irregular flexible packaging material 400 during high-speed transportation. The multi-field coupled end effector 200 constructed in step S1 is essentially a physically programmable interactive interface, in which the particle blockage layer cavity 210 serves as the direct contact medium. Utilizing the non-Newtonian fluid properties of the particles under normal pressure and combined with the macroscopic flexibility of the pneumatic artificial muscle skeleton 230, complete adhesion and coverage of the irregular folds on the surface of the material to be grasped, such as flour bags and feed bags, is achieved in step S2.

[0052] Step S3 introduces a negative pressure field through the pneumatic control system 300, causing the vacuum level of the inner cavity 210 of the particle blockage layer to rapidly reach the phase transition threshold of -0.08MPa to -0.04MPa. At this point, the internal particles instantly change from a fluid state to a near-solid state, forming a rigid shell that perfectly matches the current shape of the material. Simultaneously, the expansion pressure generated by inflating the outer cavity 220 of the reverse prestressed gas chamber is designed to counteract the volume contraction trend caused by the vacuuming of the particle layer, thereby maintaining the consistency of the gripping center while locking the material shape. This rigid molding effect enables the robotic arm system 100 in step S4 to perform variable trajectory conveying at high acceleration without worrying about shaking or slipping inside the material. When reaching step S5, the system does not simply cut off the vacuum, but instead introduces a high-frequency pulsed airflow and detects the implicit physical characteristic of the airflow back pressure change rate to reverse-engineer the support situation on the surface of the lower stack 500, and then dynamically adjusts the depressurization speed to ensure that the material flows smoothly into the stacking position, thereby achieving high-density stable stacking on unstructured surfaces.

[0053] The airflow back pressure change rate is a dynamic indicator that reflects the contact density between the end effector and the stack surface. Its physical meaning is to characterize the local stiffness of the support surface by the diffusion resistance of high-frequency airflow at the contact interface. This parameter is collected in real time by the micro differential pressure sensor 320. Its value directly determines whether the bottom is a solid plane or a loose void, and is the core basis for executing the adaptive pressure relief logic.

[0054] The steps preceding S5 include:

[0055] The pre-built flow resistance-deformation-stiffness mapping model is invoked, and the local support stiffness of the stacked surface and the real-time impedance characteristics at release are used as the correlation objects to calculate the compensation stiffness value required to maintain the material shape.

[0056] The calculation logic is as follows: The input sources are the instantaneous back pressure signal collected by the differential pressure sensor 320 and the fluctuation signal of the flow meter. Step 1: The controller calculates the flow resistance characteristics by extracting the rising edge slope of the pulse waveform; Step 2: Based on the preset material deformation coefficient, the instability trend of the current material under gravity is mapped; Step 3: The compensation stiffness value is output; this value ultimately points to the negative pressure depth that the particle blockage layer cavity 210 needs to maintain, thereby achieving the technical effect of using internal rigidity to offset insufficient external support.

[0057] During the calculation process using the flow resistance-deformation-stiffness mapping model:

[0058] In the flow resistance-deformation-stiffness mapping model, the compensation stiffness value is a function of the pulse airflow pressure change rate and flow fluctuation, and the aerodynamic impedance characteristics include the pulse airflow pressure change rate.

[0059] This embodiment is a further development of the release control logic in step S5, aiming to establish a quantitative relationship between physical perception and stiffness control. The flow resistance-deformation-stiffness mapping model constructed in step S5.1 is established to indirectly quantify the local support stiffness of the contact surface through aerodynamic feedback when the micro-morphology of the stack surface cannot be directly observed. The model consists of an aerodynamic signal feature extraction layer and a stiffness compensation decision layer in terms of logical structure. The data flow starts from the original signal input of the sensor, is transformed into aerodynamic impedance index through feature extraction, and is finally input into the decision layer to calculate the stiffness compensation value.

[0060] In terms of physical characterization, the model simulates the diffusion dynamics of high-frequency airflow in the contact interface of porous media, characterizes the physical law of positive correlation between airflow diffusion resistance, flow resistance and contact surface density, support stiffness, and the mechanical balance relationship between the deformation trend of materials under gravity and the compensation stiffness required to maintain the shape.

[0061] Specifically, the calculation logic of the above flow resistance-deformation-stiffness mapping model is as follows:

[0062] Step 1: Data Acquisition. The system uses a 320 micro differential pressure sensor to... The sampling rate acquires real-time pressure values ​​during pulsed gas injection. Simultaneously, the flow rate value of the micro-flow sensor is collected. ;

[0063] Step 2: Feature Extraction. The controller extracts the time window of the pulse airflow rise edge and calculates the slope of the pressure-time curve within this window as the pulse airflow pressure change rate. Simultaneously, it calculates the standard deviation of the flow rate during the pulse's steady-state period as the flow rate fluctuation. Specifically, the pulse airflow pressure change rate... With traffic fluctuations The calculation expression is as follows:

[0064]

[0065] In the formula, This represents the peak pressure value of the pulse wave. The pressure value at the moment of pulse initiation. This is the instantaneous flow rate value. The average flow rate within the pulse period. The sampling period;

[0066] Step 3: Stiffness Mapping Calculation. The system inputs the extracted feature values ​​into the stiffness compensation decision layer and calculates the compensation stiffness value based on the preset logical model. Among them, theoretical limit stiffness The weighted correction has been applied based on a preset material deformation coefficient. This logic simulates the following physical causal chain: When higher and A lower value indicates that the contact surface is a dense, hard surface with high flow resistance, sufficient external support, and a required compensation stiffness value. Smaller;

[0067] Conversely, when When the flow rate is low and the airflow dissipates rapidly, it indicates that the contact surface is loose or uneven, the flow resistance is low, and the external support is insufficient, requiring an increase in flow rate. The physical causal chain that utilizes the internal stress of the particle layer to maintain the material's shape is quantitatively defined by the following functional relationship:

[0068]

[0069] In the formula, This represents the theoretical ultimate stiffness of the particle blocking layer under maximum vacuum. The threshold for the rate of change of pressure is used to determine the tightness of the contact surface; This is the stiffness attenuation coefficient, in units of... , used to normalize the rate of change of pressure, and used to adjust the sensitivity to hard surfaces; This is the flow fluctuation gain coefficient, in units of or Depending on the unit of flow, it is used to normalize flow fluctuation values, ensuring that the exponent term is a dimensionless value; when flow fluctuations exist... When the contact surface leaks or becomes unstable, the compensation stiffness value is increased in a positive direction. To enhance the ability to lock onto materials;

[0070] Among them, the above-mentioned stiffness attenuation coefficient With flow fluctuation gain coefficient It was obtained through a standardized mechanical calibration experiment conducted in advance: a standard rigid plane and a standard loose porous medium were selected as reference objects, the aerodynamic response boundary values ​​of the system were measured, and then calculated through linear regression and normalization to ensure the adaptability of the model to different material surfaces.

[0071] To further improve control accuracy, vacuum control commands... The calculated compensation stiffness value Satisfying the following mapping function:

[0072]

[0073] in, The system gain coefficient. It is a nonlinear correction factor. As the fundamental vacuum bias, A possesses the physical properties of the dimensions on both sides of the equilibrium formula, and its unit depends on... The values ​​of the above parameters are calibrated based on preset mechanical test data for different types of materials;

[0074] Specifically, the compensation stiffness value The mapping relationship between the vacuum degree control command and the vacuum degree control command is obtained through a mechanical calibration experiment on the particle blockage layer in advance, and is stored in the controller in the form of a lookup matrix or a fitting function.

[0075] Step 4: Output the results, the calculated values. It is converted into a corresponding vacuum control command, such as −0.03MPa, as the basis for maintaining the semi-rigid state in step S5;

[0076] The physical significance of this calculation process is that the system determines how much residual hardness of the particle layer needs to be retained during the release process to bridge the uneven areas based on how soft or uneven the lower stack 500 is, thereby avoiding tilting or collapse caused by the instantaneous complete softening of the material, and realizing active adaptive stacking based on environmental feedback.

[0077] The steps in S5 include:

[0078] Control the multi-field coupled end effector 200 to press down and contact the surface of the lower stack 500;

[0079] A high-frequency pulsed airflow with a frequency of 20Hz to 50Hz is introduced into the inner cavity 210 of the particle blockage layer; at this time, the peak pressure of the pulsed airflow needs to be set higher than the current absolute pressure of the inner cavity to ensure that the airflow can effectively enter and generate a detectable back pressure disturbance.

[0080] If the rate of change of airflow back pressure is detected to be lower than the preset flatness threshold, the vacuum degree of the particle blockage layer cavity 210 is maintained in the semi-rigid threshold range of -0.03MPa to -0.01MPa, and the vacuum degree is linearly reduced until it returns to zero during the lifting process of the robotic arm system 100.

[0081] This threshold range simulates the intermediate phase state of matter between the fluid and solid states; its logical function is to make the particle layer retain a weak interlocking force at the moment of withdrawal, so as to provide an instantaneous truss support effect when the material's own weight presses on the uneven surface, preventing the material from sliding into the bottom gap due to instantaneous complete softening and causing tilting.

[0082] If the rate of change of airflow back pressure is detected to be higher than or equal to the smoothness threshold, the inner cavity 210 of the particle blockage layer is directly restored to the normal pressure state.

[0083] This embodiment specifically illustrates the adaptive control strategy in the release phase. In step S5, a high-frequency pulsed airflow with a frequency of 20Hz to 50Hz is selected because the airflow in this frequency band can effectively penetrate the gaps between particles and will not cause macroscopic material vibration. When the system detects that the airflow back pressure change rate is lower than the preset flatness threshold, it indicates that there is a risk of unevenness or insufficient support on the surface of the lower stack 500.

[0084] In this process, the airflow back pressure change rate is not a single instantaneous value, but refers to the average slope of the back pressure signal rising from the trough to the peak within a single pulse cycle of the high-frequency pulsed airflow introduced into the particle blockage layer cavity 210. This slope directly reflects the establishment speed of the airflow at the contact interface and is a key indicator for judging the tightness of the contact surface. The preset flatness threshold is a calibration parameter. The dimension of this threshold is consistent with the airflow back pressure change rate, and the unit is megapascals per second. Its setting range is usually dynamically adjusted according to the average density of different materials. The method for determining it is as follows: during the system initialization phase, the control end effector presses against a standard rigid horizontal platform, records the airflow back pressure change rate generated at this time, and sets 80% of this value as the flatness threshold. This threshold serves as a logical boundary line to distinguish whether the contact surface is an effective surface that can provide sufficient support or a defective surface with gaps.

[0085] At this point, the system does not immediately release the vacuum, but instead locks the vacuum level of the particle blockage layer cavity 210 within a semi-rigid threshold range of -0.03MPa to -0.01MPa. This operation keeps the particle layer in a semi-solidified plate-like shape, which can act like a bridge across the uneven areas of the lower layer, providing a temporary flat base for the upper material. As the robotic arm slowly lifts and withdraws, the linearly decreasing vacuum level allows the material to gradually regain its flexibility and fill the gaps, thus achieving tight interlocking between layers while ensuring stacking verticality. Conversely, if the back pressure change rate is high, it indicates that the contact surface is flat and solid, and the system directly restores atmospheric pressure, utilizing the rapid flowability of the particles to improve stacking efficiency.

[0086] In step S1, the non-blocking filling particles 212 are a mixture of silicone particles and polystyrene microspheres, and the inner lining material of the particle blocking layer cavity 210 is silicone rubber with low elastic modulus and high tear strength.

[0087] In step S1, in the non-blocking filling particles 212, the volume ratio of silica particles to polystyrene microspheres is 3:1 to 5:1, and the average diameter of the particles is 0.5 mm to 2.0 mm.

[0088] This embodiment focuses on the influence of the material properties of the particulate blockage medium on the phase change efficiency. The non-blocking filling particles 212 are a mixture of silica gel particles and polystyrene microspheres. The silica gel particles provide a high coefficient of friction, ensuring that strong interlocking forces can be generated between the particles under vacuum negative pressure, thereby improving the shear modulus after stiffening. The polystyrene microspheres, due to their low density and sphericity, mainly act as a lubricant, ensuring that the particle layer has excellent fluidity under normal pressure, and can quickly fill the tiny wrinkles on the surface of the material.

[0089] The volume ratio is controlled between 3:1 and 5:1 and the average diameter is set between 0.5 mm and 2.0 mm. This is to balance the contradiction between rigidity and flow compliance, and to prevent vacuum pipeline blockage caused by excessively small particles or a decrease in coating resolution caused by excessively large particles.

[0090] The inner liner, made of low-modulus silicone rubber, maintains sufficient elasticity while possessing extremely high tear resistance. It can withstand repeated vacuum compression cycles and accurately transmit the phase change force of the particle layer to the material being gripped, preventing the stiffening effect of the particle layer from being negated due to excessive deformation of the inner liner.

[0091] In step S3, the inflation volume expansion of the outer cavity 220 of the reverse prestressed gas chamber is equal to the volume contraction of the inner cavity 210 of the particle blockage layer caused by vacuuming, so as to offset the radial deformation caused by the inner cavity contraction, and make the total outer contour diameter of the multi-field coupled end effector 200 remain dynamically stable on a macroscopic level.

[0092] This embodiment addresses the volume shrinkage side effect caused by the particle blockage effect. In step S3, when the inner cavity 210 of the particle blockage layer is evacuated, the particle gaps are compressed, which inevitably reduces the inner diameter of the entire end effector. This usually generates a centripetal tightening force, which may damage fragile soft packaging materials or cause the gripping center to deviate from the axis of the robotic arm. To address this, the system uses equal volume compensation logic to control the inflation volume expansion of the outer cavity 220 of the reverse prestressed gas chamber to be strictly equal to the shrinkage of the inner cavity.

[0093] The correspondence between the inner cavity's shrinkage and vacuum level is obtained through pre-experimental calibration and stored in the pneumatic control system 300 using a lookup table method. The controller directly retrieves the corresponding volume shrinkage data based on the real-time detected vacuum level value, thereby controlling the outer cavity's inflation volume.

[0094] This antagonistic volume change mechanism ensures that the expansion pressure of the outer cavity precisely counteracts the excessive centripetal force generated by the contraction of the inner cavity, thereby maintaining the overall diameter of the outer contour of the multi-field coupled end effector 200 at a constant macroscopic level. A limiting reinforcing rib is provided between each layer of the multi-field coupled end effector 200 along the axial direction. The limiting reinforcing rib is used to constrain the axial elongation of the outer cavity 220 of the reverse prestressed gas chamber during inflation, thereby forcing the volume expansion to be converted into radial displacement, ensuring that the volume compensation amount and the diameter change amount achieve decoupling balance in the geometric linear space.

[0095] At this time, the outermost pneumatic artificial muscle skeleton 230 is in an inflated and pressurized state. Its woven mesh structure provides radial rigid constraint, which forces the expansion of the outer cavity 220 of the reverse prestressed air chamber to fill the gap left by the contraction of the inner cavity 210 of the particle blocking layer inward, rather than expanding the overall outline outward, thereby strictly ensuring the constant total diameter of the outer outline.

[0096] This design ensures that the geometric center of the end effector always coincides with the calibration center of the robotic arm, regardless of the shape or volume of the material being gripped. This eliminates positioning errors caused by media deformation and plays a decisive role in maintaining trajectory accuracy during high-speed stacking.

[0097] In step S1, the pneumatic artificial muscle skeleton 230 is woven from several pneumatic muscle fibers 231, and the pneumatic muscle fibers 231 surround the outer cavity 220 of the reverse prestressed air chamber in a cage-like structure.

[0098] This embodiment describes the macroscopic mechanical skeleton structure of the end effector. The pneumatic artificial muscle skeleton 230 does not use a traditional rigid linkage, but is a cage structure woven from several pneumatic muscle fibers 231, namely McLaren-type pneumatic artificial muscle units. This structure surrounds the outer side of the reverse prestressed air chamber 220. Utilizing the biomimetic characteristics of pneumatic muscle inflation and deflation, it provides the macroscopic envelope force required for grasping. The cage-like woven structure gives the skeleton a nonlinear elastic modulus, allowing it to flexibly adapt to the general outline of the material like a net in the initial contact phase, while providing sufficient centripetal constraint force during the grasping process. This flexible skeleton, combined with the stiffness variation of the internal particle blocking layer, constitutes a composite mechanical system that is flexible on the outside and rigid on the inside. It utilizes both the load-bearing capacity of the skeleton and the fine shaping ability of the particle layer, effectively avoiding local stress concentration damage to soft materials caused by a single rigid skeleton.

[0099] Example 2:

[0100] Please see Figures 1-3 An automated material stacking device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is executed by the processor, it implements an automated material stacking method. The specific structure of the device includes:

[0101] Robotic arm system 100;

[0102] A multi-field coupled end effector 200 is disposed at the end of the robotic arm system 100; wherein, the multi-field coupled end effector 200 includes a pneumatic artificial muscle skeleton 230 for providing macroscopic envelope force, a reverse prestressed air chamber 220 located inside the pneumatic artificial muscle skeleton 230, and a particle blocking layer chamber 210 located inside the reverse prestressed air chamber 220.

[0103] The pneumatic control system 300 is connected to the pneumatic artificial muscle skeleton 230, the outer cavity 220 of the reverse prestressed air chamber, and the inner cavity 210 of the particle blockage layer, respectively; wherein, the pneumatic control system 300 is used to provide positive pressure airflow and negative pressure vacuum.

[0104] The inlet bypass detection end of the particle blockage layer cavity 210 is equipped with a high-frequency solenoid valve 310, a micro-flow sensor and a micro-differential pressure sensor 320 to accurately collect the airflow back pressure signal during the pulse interval or in a steady flow state.

[0105] This embodiment describes the hardware architecture for implementing the above method. The multi-field coupled end effector 200 adopts a layered concentric layout, consisting of, from the outside to the inside, a pneumatic artificial muscle skeleton 230 that provides basic clamping force, an outer cavity 220 of the reverse prestressed air chamber responsible for volume balance, and an inner cavity 210 of the particle blocking layer that performs phase change locking. The pneumatic control system 300 acts as the energy distribution center, providing the required positive pressure airflow or negative pressure vacuum to these three functional layers through independent air paths, thereby achieving decoupled control and synergistic effect of the three physical fields.

[0106] Specifically, a high-frequency solenoid valve 310 and a micro differential pressure sensor 320 are integrated at the air inlet of the particle blockage layer cavity 210. The high-frequency solenoid valve 310 is responsible for generating the pulsed airflow required for the aforementioned detection, the micro flow sensor is used to monitor the instantaneous flow fluctuations in the air path in real time, and the micro differential pressure sensor 320 is configured to sensitively capture millisecond-level airflow back pressure signals. This sensor layout scheme transforms the end effector into an intelligent terminal with tactile sensing capabilities, enabling the device to collect and feedback the flow resistance information of the contact interface in real time while performing physical grasping, providing key data support for the control system to perform stiffness compensation and release strategy adjustment.

[0107] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for automatic stacking of material, characterized in that, include: S1. A pneumatic control system (300) and a robotic arm system (100) are set up. A multi-field coupled end effector (200) is installed at the end of the robotic arm system (100). The multi-field coupled end effector (200) includes, from the inside to the outside: a particle blocking layer cavity (210) filled with non-Newtonian fluid characteristic particles (212), a reverse prestressed air chamber cavity (220), and a pneumatic artificial muscle skeleton (230). S2. Control the robotic arm system (100) to the gripping position, maintain the normal pressure of the inner cavity (210) of the particle blockage layer and the outer cavity (220) of the reverse prestressed air chamber, and use the pneumatic artificial muscle skeleton (230) to provide macroscopic enveloping force to cover the amorphous soft packaging material (400). S3. Start the pneumatic control system (300) to evacuate the inner cavity (210) of the particle blockage layer to -0.08MPa~-0.04MPa, and at the same time inflate the outer cavity (220) of the reverse prestressed gas chamber. The inflation pressure is positively correlated with the volume shrinkage of the inner cavity (210) of the particle blockage layer. S4, Drive the robotic arm system (100) to transport materials to the top of the stacking point at high speed by changing the trajectory; S5. Perform a release operation based on aerodynamic impedance feedback, introduce high-frequency pulsed airflow into the inner cavity (210) of the particle blockage layer and detect the back pressure change rate, and adjust the vacuum level maintenance threshold and pressure relief strategy accordingly to complete the stacking.

2. A method of automatic material storage according to claim 1, characterized in that In step S5, before adjusting the pressure relief rate, the following is also included: The pre-built flow resistance-deformation-stiffness mapping model is invoked, and the local support stiffness of the stacked surface and the real-time impedance characteristics at release are used as the correlation objects to calculate the compensation stiffness value required to maintain the material shape.

3. A method of automatic material storage according to claim 2, characterized in that, During the calculation process using the aforementioned flow resistance-deformation-stiffness mapping model: In the flow resistance-deformation-stiffness mapping model, the compensation stiffness value is a function of the pulse airflow pressure change rate and flow fluctuation, and the aerodynamic impedance characteristics include the pulse airflow pressure change rate.

4. A method of automatic material storage according to claim 1, characterized in that, The steps in S5 include: Control the multi-field coupled end effector (200) to press down and contact the surface of the lower stack body (500); A high-frequency pulsed airflow with a frequency of 20Hz to 50Hz is introduced into the inner cavity (210) of the particle blockage layer; at this time, the peak pressure of the pulsed airflow needs to be set higher than the current absolute pressure of the inner cavity to ensure that the airflow can effectively enter and generate a detectable back pressure disturbance. If the rate of change of the airflow back pressure is detected to be lower than the preset flatness threshold, the vacuum degree of the inner cavity (210) of the particle blockage layer is maintained in the semi-rigid threshold range of -0.03MPa to -0.01MPa, and the vacuum degree is linearly reduced until it returns to zero during the lifting process of the robotic arm system (100). If the rate of change of the airflow back pressure is detected to be higher than or equal to the smoothness threshold, the inner cavity (210) of the particle blockage layer is directly restored to the normal pressure state.

5. A method of automatically stacking material according to claim 1, characterized in that, In step S1, the non-Newtonian fluid characteristic particles (212) are a mixture of silica gel particles and polystyrene microspheres, and the lining material of the particle blockage layer cavity (210) is silicone rubber with low elastic modulus and high tear strength.

6. A method of automatically stacking material according to claim 1, wherein, In step S3, the inflation volume expansion of the outer cavity (220) of the reverse prestressed gas chamber is equal to the volume contraction of the inner cavity (210) of the particle blockage layer caused by vacuuming, so as to offset the radial deformation caused by the inner cavity contraction, and make the total outer diameter of the multi-field coupled end effector (200) remain dynamically stable on a macroscopic level.

7. A method of automatically stacking material according to claim 1, wherein, In step S1, the pneumatic artificial muscle skeleton (230) is woven from a number of pneumatic muscle fibers (231), and the pneumatic muscle fibers (231) surround the outer cavity (220) of the reverse prestressed air chamber in a cage-like structure.

8. The automated material stacking method according to claim 1, characterized in that, In step S1, the volume ratio of silica gel particles to polystyrene microspheres in the non-Newtonian fluid characteristic particles (212) is 3:1 to 5:1, and the average diameter of the particles is 0.5 mm to 2.0 mm.

9. An automatic material piling device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements an automated material stacking method as described in any one of claims 1-8; The specific structure of the device includes: Robotic arm system (100); A multi-field coupled end effector (200) is disposed at the end of the robotic arm system (100); wherein the multi-field coupled end effector (200) includes a pneumatic artificial muscle skeleton (230) for providing macroscopic envelope force, a reverse prestressed gas chamber (220) located inside the pneumatic artificial muscle skeleton (230), and a particle blocking layer chamber (210) located inside the reverse prestressed gas chamber (220). The pneumatic control system (300) is connected to the pneumatic artificial muscle skeleton (230), the reverse prestressed air chamber (220), and the particle blockage layer inner cavity (210) respectively; wherein, the pneumatic control system (300) is used to provide positive pressure airflow and negative pressure vacuum.

10. An automated material storage and retrieval system according to claim 9, wherein, The inlet bypass detection end of the particle blockage layer cavity (210) is equipped with a high-frequency solenoid valve (310), a micro-flow sensor and a micro-differential pressure sensor (320) to accurately collect the airflow back pressure signal during the pulse interval or in a steady flow state.

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