Adjustable multifunctional clamping and positioning method for wood-working machining

Abstract

The invention relates to the field of machining, and discloses an adjustable wood-working machining multifunctional clamping and positioning method which comprises the following steps: S1, acquiring three-dimensional space position information of a workpiece through laser scanning, and generating point cloud data containing a texture trend; s2, analyzing geometrical characteristics and mechanical characteristics of the workpiece based on the point cloud data, generating a clamping position distribution instruction and matching a clamping mode; s3, a grading pressure threshold value is set according to the wood density grade, and cooperative force application control of multiple clamping arms is dynamically adjusted based on distributed pressure feedback; and S4, fusing the vibration spectrum and the visual displacement data to monitor the position offset of the workpiece in real time. Through a dynamic pressure balancing strategy, according to wood density grading, pressure threshold values are set, gradient pressure control is conducted on hardwood, slope changes are limited, pre-pressing relaxation time is configured for cork wood, multiple clamping arms are adjusted in real time to cooperatively apply force through distributed feedback, and the structural integrity of wood of different densities is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing, in particular to an adjustable multifunctional clamping and positioning method for woodworking mechanical processing. Background Art

[0002] As a natural biomass material, wood has significant density gradient differences. The mechanical response characteristics of hardwood and softwood during processing are essentially different. Traditional clamping devices are difficult to adaptively adjust force parameters. The pressure distribution balance when multiple clamping arms work together directly affects the structural stability of the workpiece. High-precision woodworking machining places higher requirements on the dynamic response capability and material adaptability of the clamping system.

[0003] Existing clamping technology has the problem of insufficient adaptation between force parameters and the physical properties of wood. The use of a single pressure setting leads to unstable clamping of hardwood or crushing damage to softwood. There is a lack of a graded pressure control mechanism for density differences. The force application process cannot limit the slope of the pressure gradient change, causing local stress concentration. The multiple clamping arms have poor coordination and lack dynamic feedback adjustment capabilities, making it difficult to ensure the structural integrity of wood of different densities. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides an adjustable multifunctional clamping and positioning method for woodworking machinery processing, which solves the problem that the existing technology uses a single pressure parameter and is difficult to adapt to the difference in wood density, resulting in loose clamping of hardwood or crushing damage of softwood, lacks a graded pressure control mechanism, and uncontrolled force gradient changes causing local stress concentration.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] An adjustable multifunctional clamping and positioning method for woodworking machining comprises the following steps:

[0007] S1. Obtain the three-dimensional spatial position information of the workpiece through laser scanning and generate point cloud data including texture direction;

[0008] S2, analyze the workpiece geometric features and mechanical properties based on point cloud data, generate clamping position distribution instructions and match the clamping mode;

[0009] S3, setting graded pressure thresholds according to wood density levels, and dynamically adjusting the coordinated force control of multiple clamping arms based on distributed pressure feedback;

[0010] S4, integrating vibration spectrum and visual displacement data to monitor workpiece position offset in real time;

[0011] S5. Trigger a hierarchical security response mechanism based on monitoring data.

[0012] Preferably, in step S1, the point cloud data includes wood texture vector information for identifying the clamping risk position in the anisotropic region, and the positioning error generated during the scanning process is controlled within the range of 0.03 mm.

[0013] Preferably, in the step S2, the clamping position distribution instruction is generated based on the point cloud curvature analysis, and contour clamping points are allocated to high curvature areas, vacuum adsorption points are allocated to plane areas, and anti-shear positioning points are allocated to high shear risk areas.

[0014] Preferably, in step S3, the synergistic force field control adopts a dynamic pressure balance strategy:

[0015] Density>0.6g / cm 3 For hardwood, set the pressure range to 1.8-3.2MPa and the gradient slope ≤ 0.5MPa / cm;

[0016] Density ≤0.6g / cm 3 For cork, the pressure range is 0.9-1.5MPa and the pre-compression relaxation time is set to 3-5 seconds.

[0017] Preferably, in the step S4, the position offset monitoring integrates sub-pixel visual positioning and vibration energy vector analysis, and the visual positioning accuracy reaches 0.005 mm. When the displacement exceeds 0.15 mm, a compensation instruction is triggered.

[0018] Preferably, the dynamic pressure equalization strategy includes:

[0019] When the local pressure deviation exceeds 12% of the set value, a fuzzy PID compensation instruction is generated to control the adjacent clamping arms to output the compensation force field within 80ms. The compensation amount satisfies the formula:

[0020]

[0021] Among them: K p The value range is 0.80~0.90; K d The value range is 0.10~0.14;

[0022] F comp Indicates the compensation force output value, in N;

[0023] ΔP represents the local pressure deviation, the unit is MPa;

[0024] Indicates the pressure deviation change rate, in MPa / ms.

[0025] Preferably, the compensation instruction is linked to the speed reduction control of the machining spindle until the displacement returns to a safety threshold.

[0026] Preferably, the hierarchical response mechanism of step S5 includes:

[0027] Level 1 response: dust concentration exceeds 20 mg / m 3 Activate the environment purification command;

[0028] Secondary response: Generates damping control instructions and spectrum diagnostic reports when vibration energy exceeds the set threshold;

[0029] Level 3 response: When the displacement continues to exceed the safety threshold, an emergency stop command is triggered and the workpiece constraint is released.

[0030] Preferably, in the step S2, the clamping position distribution instruction is associated with a dynamic anti-collision strategy, and a 3 to 12 mm virtual safety buffer zone is constructed in the clamping arm motion path. The buffer zone boundary is updated in real time with the posture data at a frequency of ≥10 Hz to avoid conflicts in the clamping arm motion path.

[0031] Preferably, the present invention also provides an adjustable multifunctional clamping system for woodworking machinery, comprising:

[0032] Spatial positioning module, used to generate workpiece three-dimensional position information and texture vector diagram;

[0033] Intelligent decision-making module, used to generate gripping point distribution instructions and end-effector matching strategies;

[0034] Collaborative force control module, used to achieve dynamic balance of force applied by multiple clamping arms;

[0035] Displacement monitoring module, used to fuse vibration and visual data to calculate position offset;

[0036] Path planning module, used to build dynamic safety buffer zones and update the gripper arm motion path;

[0037] Security protection module, used to trigger graded response instructions.

[0038] The present invention provides an adjustable multifunctional clamping and positioning method for woodworking machinery processing. It has the following beneficial effects:

[0039] 1. The dynamic pressure equalization strategy in this invention sets the pressure threshold according to the wood density classification, implements gradient pressure control and limits the slope change for hardwood, configures pre-compression relaxation time for softwood, and adjusts the coordinated force of multiple clamping arms in real time through distributed feedback to ensure the structural integrity of wood of different densities.

[0040] 2. The present invention actively avoids clamping risk positions caused by texture through high-precision point cloud analysis, and uses a 0.03 mm positioning error tolerance to constrain the accuracy of clamping instruction generation, effectively eliminating clamping damage caused by the anisotropic properties of wood.

[0041] 3. The present invention obtains point cloud data containing texture vectors through laser scanning to generate anisotropic regional risk maps, and combines multi-mode strategies such as point cloud curvature analysis, adaptive matching, contour clamping and vacuum adsorption to achieve precise clamping planning based on the texture characteristics of wood.

[0042] 4. The safety protection mechanism of the present invention integrates displacement monitoring and three-level response, integrates sub-pixel visual positioning and vibration spectrum analysis to track micro-deflections in real time, and links dust purification, vibration damping and emergency stop release instructions to form a multi-dimensional protection network, achieving all-round protection from process intervention to emergency avoidance. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a flow chart of the adjustable multifunctional clamping and positioning method for woodworking machinery processing according to the present invention;

[0044] Figure 2 Schematic diagram of the structure of the adjustable multifunctional clamping system for woodworking machinery of the present invention. DETAILED DESCRIPTION

[0045] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0046] Please see the attached Figure 1 - Attachment Figure 2 , an embodiment of the present invention provides an adjustable multifunctional clamping and positioning method for woodworking machinery processing, comprising the following steps:

[0047] S1. Obtain the three-dimensional spatial position information of the workpiece through laser scanning and generate point cloud data including texture direction;

[0048] S2, analyze the workpiece geometric features and mechanical properties based on point cloud data, generate clamping position distribution instructions and match the clamping mode;

[0049] S3, setting graded pressure thresholds according to wood density levels, and dynamically adjusting the coordinated force control of multiple clamping arms based on distributed pressure feedback;

[0050] S4, integrating vibration spectrum and visual displacement data to monitor workpiece position offset in real time;

[0051] S5. Trigger a hierarchical security response mechanism based on monitoring data.

[0052] Specifically, in step S1, laser scanning is first used to obtain three-dimensional point cloud data containing wood texture vectors, and an anisotropic feature space model is established. In step S2, the point cloud curvature and mechanical properties are analyzed to obtain the clamping point distribution instructions, and a mixed clamping method such as dynamic adaptive contour clamping and vacuum adsorption is performed. In step S3, a graded pressure threshold is set according to the difference in wood density, and distributed feedback is performed on the resultant force field of multiple clamping arms based on the threshold for dynamic adjustment. In step S4, sub-pixel visual positioning is combined with vibration spectrum analysis to continuously monitor the microscopic displacement changes of the workpiece. At the same time, based on step S5, a three-level linkage response mechanism of dust concentration, vibration energy, and displacement threshold is constructed, thereby completing the full process closed-loop safety control from passive intervention to active protection, and achieving improved positioning accuracy and processing reliability while ensuring the integrity of the wood.

[0053] In step S1, the point cloud data contains wood texture vector information, which is used to identify the clamping risk location in the anisotropic area. The positioning error generated during the scanning process is controlled within the range of 0.03mm.

[0054] Specifically, laser scanning is used to generate point cloud data containing wood texture vector information, determine the anisotropic area of ​​the wood, and obtain the clamping risk position based on this. The clamping positioning error tolerance at this position is 0.03 mm, which ensures the generation accuracy of the clamping position distribution instructions. Under this premise, the possibility of clamping damage positions caused by texture reasons can be eliminated, the clamping safety and positioning accuracy can be improved, and the clamping safety and positioning reliability can be significantly improved.

[0055] In step S2, the clamping position distribution instructions are generated based on the point cloud curvature analysis, and contour clamping points are allocated to high curvature areas, vacuum adsorption points are allocated to plane areas, and anti-shear positioning points are allocated to high shear risk areas.

[0056] Specifically, a high-precision point cloud curvature is established for the entire profile surface, and clamping distribution instructions are intelligently generated based on the analysis results. Different differential distribution clamping strategies are adopted to greatly improve positioning reliability. By applying contoured clamping points to high-curvature surface areas, three-dimensional contour adaptive clamping is formed. Vacuum adsorption points are selected in the plane area to achieve large-scale force uniformity, and anti-shear positioning points are added to mechanically weak areas to form multi-modal collaborative clamping to avoid displacement and damage to the internal structure during processing.

[0057] In step S3, the synergistic force field control adopts a dynamic pressure balance strategy:

[0058] Density>0.6g / cm 3 For hardwood, set the pressure range to 1.8-3.2MPa and the gradient slope ≤ 0.5MPa / cm;

[0059] Density ≤0.6g / cm 3 For cork, the pressure range is 0.9-1.5MPa and the pre-compression relaxation time is set to 3-5 seconds.

[0060] Specifically, for hardwood with a density greater than 0.6g / cm3, a high-pressure area with a pressure value between 1.8 and 3.2MPa is selected, and the slope of the pressure gradient change is limited to no more than 0.5MPa / cm. A gradual pressurization method from low to high is adopted to reduce local stress concentration. Softwood with a density less than 0.6g / cm3 is placed in a low-pressure area between 0.9 and 1.5MPa, and a pre-compression relaxation time of 3 to 5s is set to prevent the soft material from collapsing. Distributed pressure feedback can be realized to adjust the collaborative force field of multiple clamping arms in real time, reducing the risk of damage to the wood structure while ensuring stable clamping of the workpiece.

[0061] In step S4, position offset monitoring integrates sub-pixel visual positioning and vibration energy vector analysis, with a visual positioning accuracy of 0.005 mm. When the displacement exceeds 0.15 mm, a compensation instruction is triggered.

[0062] Specifically, a high-precision displacement monitoring system is established by integrating sub-pixel visual positioning and vibration energy vector analysis, achieving visual positioning with an accuracy of 0.005 mm to detect tiny displacements of wood. Combined with vibration spectrum analysis, online real-time solution of the processing disturbance energy vector is realized. When the comprehensive monitoring data determines that the displacement is greater than the critical threshold of 0.15 mm, dynamic compensation instructions are quickly issued to the linked clamping mechanism and the processing spindle within 5 milliseconds to collaboratively complete the workpiece position offset correction and compensation, ensuring that the workpiece position offset is controlled within the process safety window, and avoiding the problem of increased dimensional error caused by cumulative errors in the precision machining process.

[0063] Dynamic pressure equalization strategy includes:

[0064] When the local pressure deviation exceeds 12% of the set value, a fuzzy PID compensation instruction is generated to control the adjacent clamping arms to output the compensation force field within 80ms. The compensation amount satisfies the formula:

[0065]

[0066] Among them: K p The value range is 0.80~0.90; K d The value range is 0.10~0.14;

[0067] F comp Indicates the compensation force output value, in N;

[0068] ΔP represents the local pressure deviation, the unit is MPa;

[0069] Indicates the pressure deviation change rate, in MPa / ms.

[0070] Specifically, the dynamic pressure balance strategy can detect the local pressure distribution of the clamping system in real time. When the local pressure deviation is greater than 12% of the given value, a compensation signal is generated through the fuzzy PID algorithm and sent to the adjacent clamping arm driver, so that the two adjacent clamping arm drivers output a compensation force field that offsets each other within 80ms. The compensation force is calculated in real time according to a certain formula. The proportional coefficient Kp ranges from 0.8 to 0.9 to increase the deviation correction response, and the differential coefficient Kd ranges from 0.1 to 0.14 to reduce the pressure mutation amplitude, thereby achieving the pressure deviation ΔP and change rate. The coordinated control of dual parameters can effectively avoid local stress concentration and restore the pressure balance of the clamping surface within sub-second time, which can ensure the improvement of the structural integrity and processing stability of hardwood and softwood materials under high-pressure working conditions.

[0071] The compensation instruction links the machining spindle speed reduction control until the displacement returns to the safety threshold.

[0072] Specifically, based on the dynamic pressure balance strategy and the machining system linkage mechanism, when the displacement is greater than the safety threshold of 0.15mm, compensation is achieved through a two-level collaborative control method: the fuzzy PID compensation instruction is started, and the power clamping arm on the corresponding side is controlled to output a pressure compensation signal of a specified size within 80ms, which is approximately equal to the pressure balance compensation force field. At the same time, a speed reduction instruction is issued to the machining spindle. The spindle speed continuously corrects its own speed according to the proportional relationship of the displacement deviation, and compares the actual displacement of the sub-pixel visual positioning system in the process with the specified steady-state range. Only when the actual displacement of the sub-pixel visual positioning system returns to the ±0.05mm range can the process continue to run, and the entire linkage mechanism is maintained so that the clamping compensation force field generation process and the spindle dynamic speed regulation process can complete the closed-loop response within 200ms, eliminating the cumulative displacement error while ensuring the continuity of precision machining.

[0073] The hierarchical response mechanism of step S5 includes:

[0074] Level 1 response: dust concentration exceeds 20 mg / m 3 Activate the environment purification command;

[0075] Secondary response: Generates damping control instructions and spectrum diagnostic reports when vibration energy exceeds the set threshold;

[0076] Level 3 response: When the displacement continues to exceed the safety threshold, an emergency stop command is triggered and the workpiece constraint is released.

[0077] Specifically, when the dust concentration in the processing area reaches 20mg / m 3When an error occurs, the first-level response instruction of the three-level response is immediately triggered to start the high-speed airflow environment purification instruction. After multi-stage filtration, the dust can reach the safety limit. The second-level response is based on real-time monitoring of the vibration spectrum. After the energy of the characteristic frequency band exceeds the preset threshold, the active damping control instruction and the output spectrum diagnosis report are simultaneously started, and the vibration suppression mechanism is directed to reduce the vibration amplitude. If an offside occurs and the displacement has far exceeded the safety threshold, the highest level of the third-level response is entered, and an emergency stop instruction and an automatic release instruction are immediately issued to make the workpiece leave the safe boundary range of the fixture, and the machine immediately starts self-detection. This mechanism realizes multi-dimensional risk coverage from environmental hazards to machining vibration, forming a closed-loop safety control architecture with self-healing characteristics, which effectively guarantees the reliability and operational safety of the precision machining process.

[0078] In step S2, the clamping position distribution instruction is associated with a dynamic anti-collision strategy to construct a 3-12 mm virtual safety buffer zone in the clamping arm motion path. The buffer zone boundary is updated in real time with the posture data at a frequency of ≥10 Hz to avoid conflicts in the clamping arm motion path.

[0079] Specifically, an adaptive virtual safety buffer zone of 3 to 12 mm is constructed in real time during operation based on the motion trajectory of the clamping arm through calculation, and is updated in real time at a speed of not less than 10 Hz in synchronization with the posture changes of the clamping arm, thereby realizing a buffer zone for millimeter-level spatial obstacle avoidance. At the same time, the system can continuously monitor the changes in the spatial geometric relationship between adjacent clamping arms and the equipment, and predict the possible dangerous state of movement based on the predicted motion path. Once an intrusion is determined, the clamping point distribution instructions and motion trajectory are quickly reconstructed, and then interference and collision are avoided, thereby transforming the static protection means into a real-time dynamic spatial coordination control method, further improving the safety of the coordinated movement of multiple clamping arms, and greatly reducing the number of emergency stops of the system, and making the operation faster and the trajectory more flexible.

[0080] The present invention also provides an adjustable multifunctional clamping system for woodworking machinery, comprising:

[0081] Spatial positioning module, used to generate workpiece three-dimensional position information and texture vector diagram;

[0082] Intelligent decision-making module, used to generate gripping point distribution instructions and end-effector matching strategies;

[0083] Collaborative force control module, used to achieve dynamic balance of force applied by multiple clamping arms;

[0084] Displacement monitoring module, used to fuse vibration and visual data to calculate position offset;

[0085] Path planning module, used to build dynamic safety buffer zones and update the gripper arm motion path;

[0086] Security protection module, used to trigger graded response instructions.

[0087] Specifically, the spatial positioning module generates three-dimensional point cloud data containing wood texture vectors in real time, providing a basis for the intelligent decision-making module to perform anisotropic feature analysis. The intelligent decision-making module selects the appropriate position to use the end effector such as the contoured gripper or vacuum suction cup according to the clamping point distribution instruction, and coordinates the collaborative force control module to implement a dynamic pressure balance strategy according to the density characteristics of the wood, and adaptively adjusts the force of multiple clamping arms under the gradient pressure field. The displacement monitoring module detects the offset by combining sub-pixel vision with vibration spectrum data, thereby achieving millimeter-level offset tracking. The path planning module constructs the motion trajectory of the clamping arm and establishes a millimeter-level dynamic safety buffer on the trajectory, refreshing the spatial obstacle avoidance path at a frequency of 10 Hz, and then links the three-level thresholds of dust concentration, vibration energy and displacement in the safety protection module, and passes their respective data to the module to work together in the closed-loop control chain to make the clamping of the processed special-shaped wood more stable, improve the processing accuracy and achieve workpiece non-destructiveness.

[0088] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An adjustable multifunctional clamping and positioning method for woodworking machinery, characterized in that: The following steps are involved: S1. Obtain the three-dimensional spatial position information of the workpiece through laser scanning and generate point cloud data including texture direction; S2, analyze the workpiece geometric features and mechanical properties based on point cloud data, generate clamping position distribution instructions and match the clamping mode; S3, setting graded pressure thresholds according to wood density levels, and dynamically adjusting the coordinated force control of multiple clamping arms based on distributed pressure feedback; S4, integrating vibration spectrum and visual displacement data to monitor workpiece position offset in real time; S5. Trigger a hierarchical security response mechanism based on monitoring data.

2. The adjustable multifunctional clamping and positioning method for woodworking machinery processing according to claim 1 is characterized in that: In step S1, the point cloud data includes wood texture vector information, which is used to identify the clamping risk position in the anisotropic area. The positioning error generated during the scanning process is controlled within the range of 0.03 mm.

3. The adjustable multifunctional clamping and positioning method for woodworking machinery processing according to claim 1 is characterized in that: In the step S2, the clamping position distribution instruction is generated based on the point cloud curvature analysis, and contour clamping points are allocated to high curvature areas, vacuum adsorption points are allocated to plane areas, and anti-shear positioning points are allocated to high shear risk areas.

4. The adjustable multifunctional clamping and positioning method for woodworking machinery processing according to claim 1 is characterized in that: In the step S3, the synergistic force field control adopts a dynamic pressure balance strategy: Density>0.6g / cm 3 For hardwood, set the pressure range to 1.8-3.2MPa and the gradient slope ≤ 0.5MPa / cm; Density ≤0.6g / cm 3 For cork, the pressure range is 0.9-1.5MPa and the pre-compression relaxation time is set to 3-5 seconds.

5. The adjustable multifunctional clamping and positioning method for woodworking machinery processing according to claim 1 is characterized in that: In step S4, the position offset monitoring integrates sub-pixel visual positioning and vibration energy vector analysis, and the visual positioning accuracy reaches 0.005 mm. When the displacement exceeds 0.15 mm, the compensation instruction is triggered.

6. The adjustable multifunctional clamping and positioning method for woodworking machinery processing according to claim 1 is characterized in that: The dynamic pressure equalization strategy includes: When the local pressure deviation exceeds 12% of the set value, a fuzzy PID compensation instruction is generated to control the adjacent clamping arms to output the compensation force field within 80ms. The compensation amount satisfies the formula: Among them: K p The value range is 0.80~0.90; K d The value range is 0.10~0.14; F comp Indicates the compensation force output value, in N; ΔP represents the local pressure deviation, the unit is MPa; Indicates the pressure deviation change rate, in MPa / ms.

7. The adjustable multifunctional clamping and positioning method for woodworking machinery processing according to claim 5, characterized in that: The compensation instruction is linked to the speed reduction control of the machining spindle until the displacement returns to the safety threshold.

8. The adjustable multifunctional clamping and positioning method for woodworking machinery processing according to claim 1 is characterized in that: The hierarchical response mechanism of step S5 includes: Level 1 response: dust concentration exceeds 20 mg / m 3 Activate the environment purification command; Secondary response: Generates damping control instructions and spectrum diagnostic reports when vibration energy exceeds the set threshold; Level 3 response: When the displacement continues to exceed the safety threshold, an emergency stop command is triggered and the workpiece constraint is released.

9. The adjustable multifunctional clamping and positioning method for woodworking machinery processing according to claim 1, characterized in that: In the step S2, the clamping position distribution instruction is associated with a dynamic anti-collision strategy to construct a 3 to 12 mm virtual safety buffer zone in the clamping arm motion path. The buffer zone boundary is updated in real time with the posture data at a frequency of ≥10 Hz to avoid conflicts in the clamping arm motion path.

10. Adjustable multifunctional clamping system for woodworking machinery, characterized in that: The adjustable multifunctional clamping and positioning method for woodworking machinery processing according to any one of claims 1 to 9 comprises: Spatial positioning module, used to generate workpiece three-dimensional position information and texture vector diagram; Intelligent decision-making module, used to generate gripping point distribution instructions and end-effector matching strategies; Collaborative force control module, used to achieve dynamic balance of force applied by multiple clamping arms; Displacement monitoring module, used to fuse vibration and visual data to calculate position offset; Path planning module, used to build dynamic safety buffer zones and update the gripper arm motion path; Security protection module, used to trigger graded response instructions.

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