A complex double-layer tube overall bending anti-interference path planning method and related device

Abstract

The present application belongs to the technical field of numerical control bending forming of pipes, and discloses a complex double-layer pipe overall bending anti-interference path planning method and related device, comprising: obtaining the geometric parameters, multi-bending path parameters and machine tool parameters of the complex double-layer pipe to be bent, generating the overall positive bending candidate path and the overall reverse bending candidate path of the whole complex double-layer pipe respectively, and establishing the double-layer pipe equivalent space envelope model and the parameterized machine tool scene model under the fixed machine head reference system; using the double-layer pipe equivalent space envelope model and the parameterized machine tool scene model, performing full-process dynamic scanning on the overall positive bending candidate path and the overall reverse bending candidate path respectively, calculating whether there is an interference risk between the complex double-layer pipe and the obstacle, and determining the final bending direction or the priority correction object according to the scanning result to generate the anti-interference path. The present application significantly improves the safety, reliability and process planning efficiency of the numerical control bending path planning of complex spatial double-layer pipes.

Description

Technical Field

[0001] This invention belongs to the field of CNC bending forming technology for pipes, and relates to a method and related device for anti-interference path planning of complex double-layer pipe integral bending. Background Technology

[0002] Complex spatial tubing is widely used in aerospace, automotive, shipbuilding, construction machinery, energy equipment, and fluid transport systems. With increasing demands for compact equipment structures, integrated piping layouts, and lightweight designs, tubing often needs to form multiple bends, spatial turns, and bending planes within a limited space. For double-layer, sleeved, or multi-layer composite tubing, it is not only necessary to meet the target spatial shape of the outer layer, but also to consider the relative positions between the inner and outer layers, assembly gaps, equivalent outer envelope dimensions, and interlayer safety distances. Therefore, its bending path planning and forming process control are more complex than those of ordinary single-layer tubing.

[0003] Currently, complex spatial tubing is typically manufactured using CNC bending equipment. During CNC bending, the tubing is generally formed sequentially through feeding, rotation, and bending actions. Process parameters such as feeding length, rotation angle, bending angle, and bending radius control the formation of the target spatial shape. For complex spatial tubing containing multiple bending segments, the formed segments continuously change their spatial orientation during the forming process, resulting in continuous changes in their occupied space. This can easily lead to interference with bending dies, clamps, pressure dies, the machine bed, the ground, and other machine tool components. Furthermore, complex double-layered spatial tubing, due to its inner and outer layer structures, large equivalent outer envelope dimensions, and assembly deviations, may also experience spatial interference between non-adjacent bending segments, or potential interference risks between inner and outer layers due to insufficient interlayer gaps.

[0004] In practical bending process design, the same multi-bend pipe fitting may typically have two forming methods: an overall positive bending path and an overall negative bending path. An overall positive bending path refers to completing the entire forming process of the multi-bend pipe fitting in one bending direction; an overall negative bending path refers to completing the entire forming process of the same target pipe fitting using the opposite bending direction. While both may correspond to the same type of spatial tubing in their final geometric goals, their interference risks can differ significantly during actual processing due to the different motion trajectories of the formed parts of the pipe fitting relative to the machine tool, bed, ground, and fixture. Therefore, for complex spatial multi-bend pipe fittings, the key to bending path planning is not merely determining whether a particular bend segment is machinable, but rather performing a full-process scan of both the overall positive and negative bending paths of the entire pipe fitting before processing to determine whether the multi-bend pipe fitting should be formed using positive or negative bending.

[0005] However, existing bending processes for complex spatial tubing typically rely heavily on manual experience, two-dimensional unfolding calculations, final forming state verification, or single-path simulation verification. These methods often focus on whether the final shape of the tubing meets design requirements, or only perform local collision checks on a selected bending path, making it difficult to systematically compare the dynamic interference risks of overall forward and reverse bending paths during the process planning phase. Due to the lack of pre-scanning and discrimination mechanisms for the two overall bending directions, existing methods often require process engineers to rely on experience to select the forward or reverse bending direction, easily leading to problems such as numerous trial bends, long adjustment cycles, and insufficient risk assessment before processing. Especially in complex, multi-segment, double-layer spatial tubing, one overall bending direction may seem feasible in the final state, but collisions with the machine tool or already formed tubing segments may have occurred during intermediate feeding, pipe transfer, or bending processes, while another overall bending direction may have a larger safety clearance and better processing accessibility.

[0006] Furthermore, some existing collision detection methods are primarily designed for general-purpose 3D solid models, typically requiring the creation of complete 3D assembly models and interference determination through complex Boolean operations, high-precision surface contact analysis, or general-purpose collision detection engines. These methods are computationally intensive, have long model preparation cycles, and generally lack dedicated dynamic update mechanisms for the three stages of CNC bending: feeding, pipe rotation, and bending, making them difficult to quickly apply to bending path process planning. For pre-processing inspection in actual production, a path scanning method that balances computational efficiency and engineering accuracy is needed to quickly determine whether interference exists between the overall positive and negative bending paths before processing, and further compare the minimum safe clearance between the two overall paths.

[0007] For double-layer tube bending, existing methods still suffer from insufficient description of the spatial envelope of the double-layer tube. If only the centerline of a single tube or the final solid model is used for verification, it is difficult to fully consider the impact of factors such as the outer envelope radius of the double-layer tube, the relative offset between the inner and outer layers, assembly errors, and safety clearances on interference risks, which can easily lead to inconsistencies between the path planning results and the actual processing state. Summary of the Invention

[0008] The purpose of this invention is to provide a method and related device for anti-interference path planning of complex double-layer tube overall bending, which solves the problem that the existing technology lacks a mechanism for dynamic interference prediction and systematic comparison of candidate paths for overall positive bending and overall reverse bending of complex spatial double-layer tubes throughout the entire process of feeding, pipe transfer and bending. This results in bending path planning relying on manual experience trial and error, insufficient risk assessment before processing and easy interference collision.

[0009] To achieve the above objectives, the present invention employs the following technical solution: A method for preventing interference during the overall bending of complex double-layered pipes includes: Obtain the geometric parameters, multi-bend path parameters, and machine tool parameters of the complex double-layer tube to be bent; Based on the multi-bend path parameters, the overall positive bend candidate path and the overall reverse bend candidate path of the entire complex double-layer pipe are generated respectively. Based on the geometric parameters, the equivalent spatial envelope model of the double-layer pipe is established. Based on the machine tool parameters, the parametric machine tool scene model under the fixed machine head reference system is established. Using a double-layer tube equivalent spatial envelope model and a parameterized machine tool scenario model, the entire process of feeding, tube turning and bending stages of the overall positive bending candidate path and the overall reverse bending candidate path are dynamically scanned. The safety gap between the complex double-layer tube and the obstacle is calculated to determine whether there is an interference risk. Based on the scanning results, the final bending direction or priority correction object is determined to generate an anti-interference path.

[0010] Furthermore, the geometric parameters of the complex double-layer tube to be bent include target spatial geometric information, tube length, inner tube radius, outer tube radius, inner and outer layer gap, assembly deviation, and safety gap threshold; The parameters for the multi-bend path include the feeding length, turning angle, bending angle, and bending radius of each bending unit; Machine tool parameters include ground height, bed center position, bed dimensions, bending die center offset, clamping block installation deviation, pressing die installation deviation, and normal process contact exclusion area; The parametric machine tool scene model includes ground height, machine bed center position, machine bed size, bending die center offset, bending die width, clamping block size, clamping block installation deviation, pressing die size, pressing die installation deviation, and tool normal contact exclusion length.

[0011] Furthermore, the generation process of the overall positive bend candidate path and the overall negative bend candidate path for the entire complex double-layer pipe includes: The overall bending direction variable of the complex double-layer tube is:

[0012] in, Indicates the overall positive curve path. This indicates the overall reverse curve path.

[0013] The overall candidate path is then represented as:

[0014] when At that time, the overall positive curve candidate path is obtained. :

[0015] when At that time, the overall reverse bend candidate path is obtained. :

[0016] in, Indicates the overall candidate path. This indicates the total number of bending processes. Indicates the process number in the reverse sequence. This indicates the feed length of the process in the reverse sequence. This represents the rotation angle about the tube axis in the reverse sequence. Indicates the nominal bending angle in the reverse sequence. This represents the bending radius of the pipe centerline in the reverse sequence. This indicates the process number in the original sequence. This indicates the feed length of the process in the original sequence. This represents the reverse axial rotation angle in the original sequence. This represents the nominal bending angle in the original sequence. This represents the radius of curvature of the centerline in the original sequence.

[0017] Furthermore, the entire process of dynamic scanning of the overall positive bend candidate path and the overall negative bend candidate path, including the feeding stage, pipe transfer stage, and bending stage, is performed: During the feeding stage, the position of the double-layer tube along the feeding direction is updated according to the current feeding length; during the tube turning stage, the rotation posture of the double-layer tube around the machine head axis is updated according to the current tube turning angle; during the bending stage, the bending state of the double-layer tube around the bending mold is updated according to the current bending angle and bending radius, gradually forming the corresponding spatial bending segment. The candidate paths for overall positive bends and overall negative bends use the same pipe geometry parameters, the same machine parameters, the same safety clearance requirements, and the same scanning step size. The entire multi-bend pipe uses opposite overall bending directions.

[0018] Furthermore, the process of determining whether there is a risk of interference includes: In each scanning substep of the overall positive bend candidate path and the overall negative bend candidate path, the spatial distance between the double-layer tube equivalent spatial envelope model and the machine tool components, bed, ground and formed tube segment is calculated, and the presence of interference risk is determined according to the preset safety clearance requirements. When the safety gap between the double-layer tube and any object being tested is less than the preset safety gap, it is determined that there is an interference risk in the scanning state, and the corresponding bending unit, movement stage, scanning progress, interference object and minimum safety gap are recorded. For the normal contact area between the bending die, clamping block, and pressing die and the pipe fitting, a contact exclusion length is set. Within the contact exclusion length, the contact between the pipe fitting and the working die is judged as normal process contact and is not treated as abnormal interference. The state that exceeds the contact exclusion length and is less than the preset safety gap is judged as an abnormal interference risk. The safe clearance between the complex double-layered pipe and the obstacle is:

[0019] in, This represents the safe clearance between any capsule unit and an obstacle in the equivalent spatial envelope model of a double-layered tube. In the equivalent spatial envelope model of a double-layered tube, the first... The central line segment of each capsule unit Indicates the first An obstacle model, This represents the minimum distance between the center line segment and the obstacle. Indicates the equivalent outer envelope radius of the double-layer tube; Obstacles include machine tool components, machine bed, ground, pre-formed pipe sections, and non-adjacent pipe sections.

[0020] Furthermore, the method for determining the final bending direction includes: When the overall positive bend candidate path meets the safety clearance requirement, while the overall negative bend candidate path does not meet the safety clearance requirement, the overall positive bend path shall be selected. When the overall reverse bending candidate path meets the safety clearance requirement, but the overall forward bending candidate path does not meet the safety clearance requirement, the overall reverse bending path shall be selected. When both the overall positive bend candidate path and the overall negative bend candidate path meet the safety clearance requirements, the path with the larger minimum safety clearance for the entire path shall be selected first. When neither the overall positive bend candidate path nor the overall negative bend candidate path meets the safety clearance requirements, path parameter correction or machine tool parameter adjustment is triggered.

[0021] Furthermore, methods for path parameter correction or machine tool parameter adjustment include: The path parameters or machine tool parameters are corrected according to the first interference object and the interference stage. The correction includes adjusting at least one of the following: feeding length, tube angle, bending angle, bending radius, bending sequence, fixture installation deviation, machine tool avoidance posture, or safety clearance threshold. After correction, the overall positive bend candidate path and the overall negative bend candidate path are regenerated, and the entire process is scanned again until an interference-resistant bend path that meets the safety clearance requirements is obtained.

[0022] A complex double-layer pipe integral bending interference prevention path planning system includes: The parameter module is used to obtain the geometric parameters, multi-bend path parameters, and machine tool parameters of the complex double-layer tube to be bent; The modeling module is used to generate candidate paths for the overall positive bend and the overall reverse bend of the entire complex double-layer pipe based on the multi-bend path parameters, establish an equivalent spatial envelope model of the double-layer pipe based on geometric parameters, and establish a parametric machine tool scene model under a fixed machine head reference system based on machine tool parameters. The calculation module is used to perform dynamic scanning of the entire process of the overall positive bending candidate path, the tube turning stage, and the bending stage using the double-layer tube equivalent spatial envelope model and the parameterized machine tool scene model. It calculates the safety gap between the complex double-layer tube and the obstacle, determines whether there is an interference risk, and determines the final bending direction or priority correction object based on the scanning results, and generates an anti-interference path.

[0023] A terminal device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method.

[0024] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method.

[0025] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a method for interference-resistant path planning in the overall bending of complex double-layered pipes. By establishing a dynamic geometric model of the double-layered pipe, a parameterized machine tool scene model, and a dynamic interference detection model, the entire process of feeding, pipe transfer, and bending is simulated in stages and steps. The minimum safe clearance between the pipe and machine tool components, environmental obstacles, and the pipe itself is calculated in real time. This enables interference prediction, risk location, and parameter correction for the bending path of complex spatial double-layered pipes, improving the safety and reliability of bending path planning. This invention abandons the traditional approach of independently switching the direction of a single bending segment. Instead, it constructs candidate paths for both overall positive and overall negative bending for the entire multi-bend double-layered pipe. By systematically comparing and selecting the best of the two overall paths before processing, the directional consistency and process continuity of the forming process are maintained. This effectively avoids the blindness and trial-and-error costs caused by relying on manual experience to select the processing start point and bending direction. Secondly, by establishing an equivalent spatial envelope model for double-layer pipes, the outer pipe dimensions, inner and outer layer assembly gaps, relative offsets, assembly errors, and safety compensation are incorporated into a precise description of the pipe's spatial occupancy. This overcomes the shortcomings of traditional methods that rely on single-pipe centerlines or final solid models for verification, neglecting the unique structural parameters of double-layer pipes. This makes the interference detection results closer to the actual processing state. Thirdly, a centralized parametric machine tool scene model, including the ground, bed, bending die, clamping block, and pressing die, is established under a fixed machine head reference system. The theoretical assembly position and actual installation deviation are uniformly incorporated into the scanning environment. Combined with calculations of various types of safety gaps between the pipe and machine tool components, bed, ground, formed pipe segments, and non-adjacent pipe segments, a unified judgment of interference between the pipe and machine tool, the pipe and environment, the pipe and itself, and between double-layer pipes is achieved. This overcomes the shortcomings of existing general collision detection methods, such as high computational load, long model preparation cycles, and the lack of a dynamic update mechanism specifically for the bending process. Finally, by performing staged discrete scanning of the entire process of feeding, pipe turning, and bending for both positive and negative bending candidate paths, and recording the first interference object, interference stage, minimum safety clearance, and degree of interference in real time, this method can accurately locate the source of risk before processing. When neither path meets the safety requirements, priority correction and rescanning are performed based on the degree of interference and the feasibility of correction. This significantly improves the safety, reliability, and process planning efficiency of CNC bending path planning for complex spatial double-layer tubes.

[0026] Furthermore, the generation process of the overall positive bend candidate path and the overall negative bend candidate path ensures that both the overall positive bend path and the overall negative bend path are for the complete forming process of the entire complex double-layer tube rather than the independent switching of a single bending segment. This allows the two candidate paths to have comparable process parameter sequences under the same target spatial tube shape, providing two sets of input paths with clear structure and unified rules for subsequent full-process dynamic scanning.

[0027] Furthermore, clear path selection rules are given for the four different scan comparison results. The complete coverage ensures that the system can make clear decision outputs under any scan result, avoiding the dilemma of being unable to judge or requiring manual intervention, and forming a complete closed-loop logic from scanning to decision.

[0028] Furthermore, the method for path parameter correction or machine tool parameter adjustment clarifies that when neither of the two overall candidate paths meets the safety clearance requirements, the path parameters or machine tool parameters are corrected according to the first interference object and the interference stage, so that users can adjust the process parameters in a targeted manner according to the specific location and object of the first interference, rather than blindly trying. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a flowchart of the complex spatial double-layer tube bending anti-interference path planning method of Embodiment 1 of the present invention.

[0031] Figure 2 This is a scan result of the minimum safety clearance for the overall positive bend candidate path in Embodiment 1 of the present invention.

[0032] Figure 3 This is a scan result of the minimum safety clearance for the overall reverse bending candidate path in Embodiment 1 of the present invention.

[0033] Figure 4 This is a flowchart of the overall positive and negative bend candidate path selection and priority correction process in Embodiment 2 of the present invention.

[0034] Figure 5 This is a scan result diagram of the effective gap and maximum interference of the overall positive bending candidate path in Embodiment 2 of the present invention.

[0035] Figure 6 This is a scan result diagram of the effective gap and maximum interference of the overall inverted candidate path in Embodiment 2 of the present invention.

[0036] Figure 7 This is a scan result diagram of the effective gap and maximum interference of the overall inverted candidate path after modification in Embodiment 2 of the present invention.

[0037] Figure 8 This is a schematic diagram of a complex double-layer tube integral bending anti-interference path planning system, which is a preferred embodiment of the present invention.

[0038] Figure 9 This is a schematic diagram of the electronic device structure according to a preferred embodiment of the present invention. Detailed Implementation

[0039] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of this application, including various details to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0040] Obviously, the described embodiments are only some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0041] It should be noted that the terminals involved in the embodiments of this application may include, but are not limited to, mobile phones, personal digital assistants (PDAs), wireless handheld devices, tablet computers, personal computers (PCs), MP3 players, MP4 players, wearable devices (e.g., smart glasses, smartwatches, smart bracelets), smart home devices, and other smart devices.

[0042] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0043] The present invention will now be described in further detail with reference to the accompanying drawings: In this invention, the positive and negative bending paths do not refer to independently selecting a positive or negative bend for each individual bending segment. Instead, for a complex, double-layered spatial tube containing multiple bending segments, an overall positive bending candidate path and an overall negative bending candidate path are constructed. Both the overall positive bending candidate path and the overall negative bending candidate path correspond to the same target spatial tube shape, but during the actual forming process, the spatial movement trajectories of the formed tube segments relative to the machine tool bed, ground, bending die, clamping block, and pressing die differ, thus resulting in different dynamic interference risks. This invention determines the overall bending direction of the multi-bend tube by pre-scanning and comparing the two overall candidate paths.

[0044] This invention provides a method for anti-interference path planning in complex double-layer tube integral bending, specifically including the following steps: S1. Obtain the geometric parameters, multi-bend path parameters, and machine tool parameters of the complex spatial double-layer tube: Obtain the target spatial geometric information of the double-layer tube to be bent, the tube length, the inner tube radius, the outer tube radius, the gap between the inner and outer layers, the assembly deviation, and the safety gap threshold; At the same time, obtain the multi-bend path parameters, which include the feeding length Y, the tube turning angle B, the bending angle C, and the bending radius R in at least one bending process; The machine tool parameters include the ground height, the center position of the bed, the bed size, the center offset of the bending die, the clamping block installation deviation, the pressing die installation deviation, and the normal process contact exclusion area.

[0045] S2. Construct overall positive bend candidate path and overall negative bend candidate path: Based on the multi-bend path parameters, construct overall positive bend candidate path and overall negative bend candidate path for the entire complex spatial double-layer pipe respectively.

[0046] Introduce the overall bending direction variable:

[0047] in, Indicates the overall positive curve path. This indicates the overall reverse curve path.

[0048] The overall candidate path can then be represented as:

[0049] when At that time, the overall positive curve candidate path is obtained. :

[0050] when At that time, the overall reverse bend candidate path is obtained. :

[0051] in, Indicates the overall candidate path. This indicates the total number of bending processes. Indicates the process number in the reverse sequence. This indicates the feed length of the process in the reverse sequence. This represents the rotation angle about the tube axis in the reverse sequence. Indicates the nominal bending angle in the reverse sequence. This represents the bending radius of the pipe centerline in the reverse sequence. This indicates the process number in the original sequence. This indicates the feed length of the process in the original sequence. This represents the reverse axial rotation angle in the original sequence. This represents the nominal bending angle in the original sequence. This represents the radius of curvature of the centerline in the original sequence.

[0052] Therefore, both the overall positive bend candidate path and the overall negative bend candidate path correspond to the complete forming process of the entire multi-bend pipe, rather than switching between positive and negative bends independently for each bending unit.

[0053] S3. Establish an equivalent spatial envelope model for the double-layer tube: Based on the geometric parameters of the inner and outer layers of the complex spatial double-layer tube, determine the equivalent outer envelope radius of the double-layer tube. The equivalent outer envelope radius can be determined by the inner layer tube radius, outer layer tube radius, inner and outer layer gap, assembly deviation, and safety gap threshold. Discrete the centerline of the double-layer tube into several centerline segments, and construct capsule units with each centerline segment and the equivalent outer envelope radius. Multiple capsule units form a double-layer tube capsule chain model, which is used to characterize the dynamic space occupancy range of the double-layer tube during feeding, tube transfer, and bending processes. The equivalent spatial envelope model of the double-layer tube is used to calculate the spatial gap between the double-layer tube and machine tool components, bed, and ground, as well as to calculate the self-interference risk between the formed sections of the double-layer tube.

[0054] S4. Establish a centralized parametric machine tool scene model under a fixed machine head reference system: Establish a fixed machine head reference system, using the feeding direction, main bending direction, and secondary bending direction as the basic directions for machine tool scene modeling. Under this fixed machine head reference system, parametrically describe the ground, bed, bending die, clamping block, and pressing die in the machine tool scene. The parametric machine tool scene model includes ground height, bed center position, bed dimensions, bending die center offset, bending die width, clamping block dimensions, clamping block installation deviation, pressing die dimensions, pressing die installation deviation, and tool normal contact exclusion length. The positions of machine tool components are determined by both theoretical assembly positions and actual installation deviations. In this way, installation errors, fixture offsets, and machine adjustment deviations in the actual machine tool can be incorporated into the path scanning process, allowing for comparison of overall positive bending candidate paths and overall negative bending candidate paths under the same actual machine tool parameter environment.

[0055] S5. Perform full-process dynamic scanning of the overall positive bend candidate path and the overall reverse bend candidate path respectively: Following the same scanning rules, perform full-process dynamic scanning of the overall positive bend candidate path and the overall reverse bend candidate path respectively. During the scanning process, each overall candidate path is sequentially expanded according to the bending unit order in the multi-bend path parameters. For each bending unit, it is decomposed into a feeding stage, a tube rotation stage, and a bending stage, and each stage is further divided into multiple scanning sub-steps. In the feeding stage, the position of the double-layer tube along the feeding direction is updated according to the current feeding length; in the tube rotation stage, the rotation attitude of the double-layer tube around the machine head axis is updated according to the current tube rotation angle; in the bending stage, the bending state of the double-layer tube around the bending die is updated according to the current bending angle and bending radius, and the corresponding spatial bending segment is gradually formed. The overall positive bend candidate path and the overall reverse bend candidate path use the same pipe geometry parameters, the same machine tool parameters, the same safety clearance requirements, and the same scanning step size. The difference between the two is that the entire multi-bend pipe uses opposite overall bending directions, therefore, during the forming process, the spatial movement trajectory of the formed pipe segment relative to the machine tool components, bed, and ground is different. During the tube-turning stage, the machine tool components remain stationary within a fixed head reference frame and do not rotate with the tube, reflecting the relative motion relationship of the tube rotating and the machine tool remaining stationary in a real machine tool. In subsequent bending unit scanning, the previously formed bending segment continues to participate in interference judgment as part of the overall space occupied by the double-layer tube, thus reflecting the dynamic attitude changes of the entire complex spatial double-layer tube during continuous processing. Through the above scanning, the dynamic spatial states of the overall positive bend candidate path and the overall reverse bend candidate path during the complete forming process are obtained, providing a basis for subsequent safety clearance calculation and bending direction determination.

[0056] S6. Calculate the safety clearance and interference state of the two overall candidate paths: In each scanning substep of the overall positive bend candidate path and the overall reverse bend candidate path, calculate the spatial distance between the equivalent spatial envelope model of the double-layer tube and the machine tool components, bed, ground, and formed tube segment, and determine whether there is an interference risk based on the preset safety clearance requirements. When the effective safety clearance between the double-layer tube and any object being detected is less than the preset safety clearance, it is determined that there is an interference risk in this scanning state, and the corresponding bending unit, motion stage, scanning progress, interference object, and minimum safety clearance are recorded.

[0057] The safe clearance between any capsule unit and an obstacle can be expressed as:

[0058] in, This represents the safe clearance between any capsule unit and an obstacle in the equivalent spatial envelope model of a double-layered tube. Indicates the first The center line segment of each capsule unit Indicates the first An obstacle model, This represents the minimum distance between the center line segment and the obstacle. This represents the equivalent outer envelope radius of the double-layer tube.

[0059] S7. Set Normal Process Contact Exclusion Zone: For the normal contact zone between the bending die, clamping block, and pressing die and the pipe fitting, set a contact exclusion length. Within the contact exclusion length, the contact between the pipe fitting and the working die is considered normal process contact and is not treated as abnormal interference; the state beyond the contact exclusion length and less than the preset safety gap is considered as an abnormal interference risk.

[0060] S8. Compare the scanning results of the overall positive curve candidate path and the overall negative curve candidate path: After completing the full-process scanning of the overall positive curve candidate path and the overall negative curve candidate path, obtain the minimum safety clearance, first interference position, first interference stage, interference object, and path feasibility judgment results for both candidate paths. Compare the scanning results of the two candidate paths: When the overall positive bend candidate path meets the safety clearance requirement, but the overall negative bend candidate path does not, the overall positive bend path is selected; when the overall negative bend candidate path meets the safety clearance requirement, but the overall positive bend candidate path does not, the overall negative bend path is selected; when both the overall positive bend candidate path and the overall negative bend candidate path meet the safety clearance requirement, the path with the larger minimum safety clearance is selected first; when neither the overall positive bend candidate path nor the overall negative bend candidate path meets the safety clearance requirement, path parameter correction or machine tool parameter adjustment is triggered.

[0061] S9. Generate an interference-resistant bending path for complex spatial double-layer tubes: Based on the comparison results of the overall positive bending candidate path and the overall negative bending candidate path, determine the final overall bending direction of the entire complex spatial double-layer tube and generate the final interference-resistant bending path. Output includes the final bending direction, feed length of each bending unit, tube turning angle, bending angle, bending radius, minimum safety clearance of the overall path, initial interference information, minimum clearance of key components, and path visualization results. When both overall candidate paths have interference risks, the path parameters or machine parameters are corrected according to the initial interference object and interference stage. The correction includes adjusting at least one of the following: feed length, tube turning angle, bending angle, bending radius, bending sequence, fixture installation deviation, machine tool avoidance posture, or safety clearance threshold. After correction, the overall positive bending candidate path and the overall negative bending candidate path are regenerated, and a full-process scan is performed again until an interference-resistant bending path that meets the safety clearance requirements is obtained.

[0062] The present invention will be further described in detail below through specific embodiments: Example 1: A path planning method where interference occurs in the overall positive curve path and the overall negative curve path meets the safety clearance requirement, such as... Figure 1 As shown.

[0063] This embodiment uses a complex spatial double-layered pipe as an example to illustrate how the present invention determines the final overall reverse bending path of the pipe by pre-scanning the overall positive bending path and the overall reverse bending path before processing.

[0064] First, the geometric parameters of the complex spatial double-layer tube to be processed are obtained. The double-layer tube includes an inner tube and an outer tube. The outer tube is used to determine the main space occupied by the tube during processing, while the inner tube and its assembly deviations are used to correct the equivalent outer envelope size of the double-layer tube. Based on the radius of the outer tube, the assembly gap between the inner and outer layers, the relative offset between the inner and outer layers, the assembly error, and the safety compensation, the equivalent spatial envelope size of the double-layer tube during the dynamic scanning process is determined.

[0065] Then, the bending process parameters for the complex double-layered tube are obtained. In this embodiment, the tube includes three bending units. Its bending path parameters are as follows: the first bending unit has a feeding length of 90 mm, a turning angle of 0°, a bending angle of 85°, and a bending radius of 100 mm; the second bending unit has a feeding length of 120 mm, a turning angle of 90°, a bending angle of 95°, and a bending radius of 55 mm; the third bending unit has a feeding length of 90 mm, a turning angle of 30°, a bending angle of 60°, and a bending radius of 70 mm.

[0066] Based on the aforementioned multi-bend path parameters, candidate paths for overall positive bends and overall negative bends are generated for the entire double-layer pipe. An overall positive bend candidate path refers to a path where all three bending units are processed in the positive bend direction; an overall negative bend candidate path refers to a path where all three bending units are processed in the negative bend direction. It should be noted that this embodiment does not separately determine positive or negative bends for the first, second, or third bend, but rather constructs two complete candidate forming paths for the entire multi-bend double-layer pipe before processing. Therefore, the overall reverse bending candidate path parameters in this embodiment are as follows: the first reverse bending unit corresponds to the third bend of the forward bend, with a feeding length of 90 mm, a pipe angle of -30°, a bending angle of 60°, and a bending radius of 70 mm; the second reverse bending unit corresponds to the second bend of the forward bend, with a feeding length of 120 mm, a pipe angle of -90°, a bending angle of 95°, and a bending radius of 55 mm; and the third reverse bending unit corresponds to the first bend of the forward bend, with a feeding length of 90 mm, a pipe angle of 0°, a bending angle of 85°, and a bending radius of 100 mm.

[0067] Subsequently, a parametric machine tool scene model is established under a fixed machine head reference frame. This machine tool scene model includes the ground, machine bed, bending die, clamping block, and pressing die. The ground is determined by the ground height parameter; the machine bed by its center position and dimensions; the bending die by its center offset and width; the clamping block by its dimensions, retraction distance, channel clearance, and installation deviation; and the pressing die by its dimensions, retraction distance, channel clearance, and installation deviation. All these machine tool parameters are centrally defined under the fixed machine head reference frame, enabling the overall positive bending candidate path and the overall negative bending candidate path to be scanned and compared within the same real machine tool scene.

[0068] Next, the centerline of the double-layer tube is discretized into several continuous line segments, and a space occupancy model of the double-layer tube is constructed based on the equivalent spatial envelope size. This model is updated in real time with feeding, tube rotation, and bending actions, and is used to describe the dynamic spatial position of the double-layer tube during processing.

[0069] During the overall positive bending candidate path scanning process, dynamic scanning is performed sequentially according to the order of the first bending unit, the second bending unit, and the third bending unit. Each bending unit is decomposed into a feeding stage, a tube rotation stage, and a bending stage. In the feeding stage, the position of the tube along the feeding direction is updated; in the tube rotation stage, the rotational attitude of the tube around the machine head axis is updated; in the bending stage, the bending state of the tube around the bending die is updated. The bending segments that have already been formed in the previous stage continue to participate in interference judgment as part of the tube space occupancy in subsequent scanning processes.

[0070] In each scanning substep, the safety clearance between the double-layer tube equivalent spatial envelope model and the bed, ground, bending die, clamping block, pressing die, and formed tube segment is calculated. For normal clamping, guiding, or supporting contacts between the bending die, clamping block, and pressing die and the tube, a normal process contact exclusion zone is set; normal process contacts within this zone are not treated as abnormal interference, while states outside this zone and with insufficient safety clearance are judged as abnormal interference.

[0071] In this embodiment, the preset safety gap is 4 mm. When the safety gap is greater than or equal to the preset safety gap, it indicates that the current scanning state meets the safety gap requirement; when the safety gap is greater than or equal to zero but less than the preset safety gap, it indicates that no physical interference has occurred but the safety gap is insufficient; when the safety gap is less than zero, it indicates that the pipe and the object being tested have already experienced physical interference, and the absolute value of this negative value represents the amount of interference in the corresponding scanning state.

[0072] like Figure 2As shown, no physical interference occurred during the dynamic scanning of the entire positive bending candidate path. The blue, orange, and purple data points in the figure represent the changes in safety clearance during the feeding, tube transfer, and bending stages, respectively. The red dashed line represents the preset safety clearance, and the black dashed line represents the contact limit. The scanning results show that the safety clearance of the overall positive bending candidate path is greater than the contact limit throughout the feeding, tube transfer, and bending processes, and the minimum safety clearance for the entire path is approximately 12.611 mm, which is 4 mm greater than the preset safety clearance. Therefore, the overall positive bending candidate path is determined to meet the anti-interference processing requirements.

[0073] like Figure 3 As shown, the overall reverse bending candidate path experienced physical interference during the entire dynamic scanning process. The scanning results indicate that the overall reverse bending candidate path experienced its first interference in the intermediate scanning stage, with the ground as the initial object of interference; subsequently, the effective gap fell below the contact limit, indicating that physical interference had occurred between the double-layer pipe and the ground. The maximum interference amount corresponding to this path was approximately 20.942 mm. Although the overall reverse bending candidate path maintained a certain gap with machine tool components such as the bed in some stages, it did not meet the anti-interference machining requirements due to physical interference with the ground.

[0074] Based on the above scanning results, the minimum safety clearance of the overall positive bending candidate path is approximately 12.611 mm, which is greater than the preset safety clearance of 4 mm, and no physical interference occurs. The overall negative bending candidate path interferes with the ground, with a maximum interference of approximately 20.942 mm. Therefore, the overall positive bending candidate path is deemed feasible, while the overall negative bending candidate path is deemed infeasible. Ultimately, the overall positive bending path is selected as the interference-resistant bending path for this complex double-layered pipe.

[0075] Finally, the overall positive bending direction is output as the final overall bending direction of this complex spatial double-layer tube, and the corresponding positive bending process parameters, minimum safety clearance of the entire path, maximum interference of the reverse bending path, first interference object, first interference stage, and path visualization results are also output.

[0076] As demonstrated in this embodiment, the present invention can dynamically scan the entire process of candidate positive and negative bend paths for the entire complex spatial double-layer tube before actual processing, and determine the final bending direction based on the effective gap and interference of the two candidate paths. This method avoids the problem of relying on manual experience to select the processing start point and bending path direction, thereby reducing the risk of interference with the ground, machine bed, or machine tool components during the bending process of the complex spatial double-layer tube.

[0077] Example 2: An anti-interference path generation method based on priority correction when neither the overall positive nor negative curve candidate paths meet safety requirements, such as... Figure 4 As shown.

[0078] This embodiment illustrates how, when neither the overall positive bend candidate path nor the overall negative bend candidate path meets the safety clearance requirements, the priority correction object is determined based on the interference object, interference stage, interference degree, and correction feasibility of the two candidate paths. Then, by correcting and re-scanning using path parameters or machine tool parameters, a complex spatial double-layer tube anti-interference bending path that meets the safety clearance requirements is obtained.

[0079] First, the geometric parameters, multi-bend path parameters, and parameterized machine tool scene parameters of the complex spatial double-layer tube are obtained. The complex spatial double-layer tube includes an inner tube and an outer tube, and its spatial occupancy is determined by the outer tube size, the assembly gap between the inner and outer layers, the relative deviation between the inner and outer layers, assembly errors, and safety compensation. The multi-bend path parameters include the feeding length, turning angle, bending angle, and bending radius of each bending unit. The parameterized machine tool scene parameters include the ground height, bed center position, bed size, bending die center offset, clamping block installation deviation, pressure die installation deviation, and the normal process contact exclusion area.

[0080] Then, based on the multi-bend path parameters, overall positive bend candidate paths and overall negative bend candidate paths for the entire complex spatial double-layer tube are generated. In this embodiment, the complex spatial double-layer tube includes three bending units: the first bending unit has a feeding length of 90 mm, a turning angle of 0°, a bending angle of 85°, and a bending radius of 100 mm; the second bending unit has a feeding length of 120 mm, a turning angle of 90°, a bending angle of 95°, and a bending radius of 55 mm; the third bending unit has a feeding length of 90 mm, a turning angle of 40°, a bending angle of 70°, and a bending radius of 60 mm. Based on the path parameters of the above three bending units, overall positive bend candidate paths and overall negative bend candidate paths are constructed respectively. It should be noted that the overall positive bend candidate paths and overall negative bend candidate paths are for the complete forming process of the entire multi-bend double-layer tube, rather than selecting positive or negative bends independently for each bending unit.

[0081] Subsequently, based on the same double-layer pipe equivalent spatial envelope model and the same parameterized machine tool scene model, the overall positive bending candidate path and the overall reverse bending candidate path were dynamically scanned throughout the entire process. Each overall candidate path was executed sequentially according to the bending unit sequence, including the feeding stage, the pipe transfer stage, and the bending stage; the bending segments that had already been formed in the previous stage continued to participate in the interference judgment as part of the pipe space occupancy during the subsequent bending unit scanning process.

[0082] During the scanning process, the safety clearances between the double-layer tube and the ground, the bed, the bending die, the clamping block, the pressing die, and the formed tube segment are calculated. In this embodiment, the preset safety clearance is 4 mm. When the safety clearance is greater than or equal to the preset safety clearance, the current scanning state is determined to meet the safety clearance requirement; when the safety clearance is greater than or equal to zero but less than the preset safety clearance, the current scanning state is determined to have a risk of insufficient safety clearance; when the safety clearance is less than zero, the current scanning state is determined to have experienced physical interference, and the absolute value of the safety clearance is taken as the interference amount in the corresponding scanning state.

[0083] like Figure 5 As shown, the overall positive bending candidate path experienced local bed interference during the full-process dynamic scanning. Scanning results indicate that the overall positive bending candidate path experienced its first interference near the end of the scanning phase, with the bed as the initial object of interference. The maximum interference amount corresponding to this path was approximately 8.000 mm; simultaneously, the minimum safe clearance between this path and the ground was approximately 92.00 mm, far exceeding the preset safe clearance, therefore there was no interference risk in the ground direction. This suggests that the risk of the overall positive bending candidate path is mainly concentrated in a localized area of ​​the bed.

[0084] like Figure 6 As shown, ground interference occurred during the entire dynamic scanning process of the overall inverted bending candidate path. Scanning results indicate that the overall inverted bending candidate path experienced its first interference in the intermediate scanning stage, with the ground as the initial object of interference. The maximum interference amount corresponding to this path was approximately 32.051 mm; simultaneously, the minimum safe clearance between this path and the machine bed was approximately 12.74 mm, which is greater than the preset safe clearance. Therefore, the machine bed direction does not pose a major risk. Thus, the main risk of the overall inverted bending candidate path is ground-direction solid interference.

[0085] Based on the above scanning results, both the overall positive bending candidate path and the overall negative bending candidate path exhibited safety clearances less than zero, therefore neither could be directly used as the final machining path. However, there are significant differences in the interference objects and degrees of interference between the two: the overall positive bending candidate path experiences localized interference with the machine bed, with a maximum interference of approximately 8.000 mm; the overall negative bending candidate path experiences solid interference with the ground, with a maximum interference of approximately 32.051 mm. In comparison, the overall positive bending candidate path exhibits a smaller degree of interference, and the interference location is concentrated in a localized area of ​​the machine bed, making it possible to eliminate the interference through correction of local path parameters or machine tool parameters. Therefore, the overall positive bending candidate path is identified as the priority for correction. This process does not involve switching a single bending unit to positive or negative bending, but rather, while maintaining the overall positive bending machining start point and execution sequence unchanged, it corrects the parameters of the bending unit or its preceding posture that causes localized machine bed interference.

[0086] Subsequently, the initial interference information of the overall reverse bending candidate path is read. This initial interference information includes the interference object, interference stage, interference position, the corresponding bending unit, and the current interference amount. In this embodiment, the initial interference object of the overall reverse bending candidate path is the machine bed, and the interference occurs near the end-scan stage, corresponding to a maximum interference amount of approximately 8.000 mm. Therefore, local corrections are preferentially performed on the end-bending unit and its preceding attitude.

[0087] Based on the initial interference information from the overall reverse bending candidate path, the interference mainly occurs near the end bending unit. Therefore, the rotation angle, bending angle, and bending radius of the third bending unit are corrected first. Before correction, the feeding length of the third bending unit is 90 mm, the rotation angle is 40°, the bending angle is 70°, and the bending radius is 60 mm. After correction, the feeding length of the third bending unit remains at 90 mm, the rotation angle is adjusted to 60°, the bending angle is adjusted to 30°, and the bending radius is adjusted to 70 mm. The path parameters of the first and second bending units remain unchanged.

[0088] The corrected multi-bend path parameters are as follows: the first bending unit has a feeding length of 90 mm, a pipe angle of 0°, a bending angle of 85°, and a bending radius of 100 mm; the second bending unit has a feeding length of 120 mm, a pipe angle of 90°, a bending angle of 95°, and a bending radius of 55 mm; and the third bending unit has a feeding length of 90 mm, a pipe angle of 60°, a bending angle of 30°, and a bending radius of 70 mm.

[0089] After parameter correction, the corrected overall positive bending candidate path is regenerated, and a second full-process dynamic scan is performed on the corrected path. The second scan is still performed in sequence according to the feeding stage, the tube transfer stage, and the bending stage, and the safety clearance between the double-layer tube and the bed, the ground, the bending die, the clamping block, the pressing die, and the formed tube section is calculated in each scanning sub-step.

[0090] like Figure 7 As shown, the secondary scan results indicate that the corrected overall positive bending candidate path did not exhibit any physical interference with a safety clearance less than zero throughout the entire process of feeding, pipe rotation, and bending. Furthermore, it no longer exhibited abnormal interference with the machine bed, ground, machine tool components, or non-adjacent pipe sections. Therefore, the corrected overall reverse bending candidate path is determined to meet the anti-interference processing requirements and is output as the final anti-interference bending path.

[0091] Finally, the corrected anti-interference bending path is output. The output includes the final overall bending direction, the feed length, tube angle, bending angle and bending radius of each bending unit, the changes of key parameters before and after correction, the minimum safe clearance of the entire corrected path, the first interference information, the minimum clearance of key components, and the path visualization results.

[0092] As demonstrated in this embodiment, when neither the overall positive bend candidate path nor the overall negative bend candidate path meets the safety requirements, this invention does not directly determine that the path planning has failed. Instead, it further compares the interference objects, interference stages, maximum interference amounts, and correction feasibility of the two candidate paths, prioritizing the overall candidate path with a smaller degree of interference and higher correction feasibility as the correction object. By correcting local path parameters or machine tool parameters and re-executing the full-process dynamic scan, a complex spatial double-layer tube anti-interference bending path that meets the safety clearance requirements can be obtained.

[0093] Example 3: This invention also provides a complex double-layer tube integral bending anti-interference path planning system, such as... Figure 8 As shown, the system includes: a parameter module, a modeling module, and a calculation module.

[0094] The parameter module is used to obtain the geometric parameters, multi-bend path parameters, and machine tool parameters of the complex double-layer tube to be bent; The modeling module is used to generate candidate paths for the overall positive bend and the overall reverse bend of the entire complex double-layer pipe based on the multi-bend path parameters, establish an equivalent spatial envelope model of the double-layer pipe based on geometric parameters, and establish a parametric machine tool scene model under a fixed machine head reference system based on machine tool parameters. The calculation module is used to perform dynamic scanning of the entire process of the overall positive bending candidate path, the tube turning stage, and the bending stage using the double-layer tube equivalent spatial envelope model and the parameterized machine tool scene model. It calculates the safety gap between the complex double-layer tube and the obstacle, determines whether there is an interference risk, and determines the final bending direction or priority correction object based on the scanning results, and generates an anti-interference path.

[0095] It is understood that the complex double-layer tube overall bending anti-interference path planning system provided by the present invention corresponds to the complex double-layer tube overall bending anti-interference path planning method provided in the foregoing embodiments. The relevant technical features of the complex double-layer tube overall bending anti-interference path planning system can be referred to the relevant technical features of the complex double-layer tube overall bending anti-interference path planning method, and will not be repeated here.

[0096] Another object of the present invention is to provide an electronic device, such as... Figure 9 As shown, it includes a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor performing the steps of the complex double-layer tube integral bending anti-interference path planning method.

[0097] The method for preventing interference during the overall bending of complex double-layer tubes includes the following steps: Obtain the geometric parameters, multi-bend path parameters, and machine tool parameters of the complex double-layer tube to be bent; Based on the multi-bend path parameters, the overall positive bend candidate path and the overall reverse bend candidate path of the entire complex double-layer pipe are generated respectively. Based on the geometric parameters, the equivalent spatial envelope model of the double-layer pipe is established. Based on the machine tool parameters, the parametric machine tool scene model under the fixed machine head reference system is established. Using a double-layer tube equivalent spatial envelope model and a parameterized machine tool scenario model, the entire process of feeding, tube turning and bending stages of the overall positive bending candidate path and the overall reverse bending candidate path are dynamically scanned. The safety gap between the complex double-layer tube and the obstacle is calculated to determine whether there is an interference risk. Based on the scanning results, the final bending direction or priority correction object is determined to generate an anti-interference path.

[0098] The fourth objective of this invention is to provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the complex double-layer tube integral bending anti-interference path planning method.

[0099] The method for preventing interference during the overall bending of complex double-layer tubes includes the following steps: Obtain the geometric parameters, multi-bend path parameters, and machine tool parameters of the complex double-layer tube to be bent; Based on the multi-bend path parameters, the overall positive bend candidate path and the overall reverse bend candidate path of the entire complex double-layer pipe are generated respectively. Based on the geometric parameters, the equivalent spatial envelope model of the double-layer pipe is established. Based on the machine tool parameters, the parametric machine tool scene model under the fixed machine head reference system is established. Using a double-layer tube equivalent spatial envelope model and a parameterized machine tool scenario model, the entire process of feeding, tube turning and bending stages of the overall positive bending candidate path and the overall reverse bending candidate path are dynamically scanned. The safety gap between the complex double-layer tube and the obstacle is calculated to determine whether there is an interference risk. Based on the scanning results, the final bending direction or priority correction object is determined to generate an anti-interference path.

[0100] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0101] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0102] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0103] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A method for anti-interference path planning in the overall bending of complex double-layer pipes, characterized in that, include: Obtain the geometric parameters, multi-bend path parameters, and machine tool parameters of the complex double-layer tube to be bent; Based on the multi-bend path parameters, the overall positive bend candidate path and the overall reverse bend candidate path of the entire complex double-layer pipe are generated respectively. Based on the geometric parameters, the equivalent spatial envelope model of the double-layer pipe is established. Based on the machine tool parameters, the parametric machine tool scene model under the fixed machine head reference system is established. Using a double-layer tube equivalent spatial envelope model and a parameterized machine tool scenario model, the entire process of feeding, tube turning and bending stages of the overall positive bending candidate path and the overall reverse bending candidate path are dynamically scanned. The safety gap between the complex double-layer tube and the obstacle is calculated to determine whether there is an interference risk. Based on the scanning results, the final bending direction or priority correction object is determined to generate an anti-interference path.

2. The method for anti-interference path planning of complex double-layer tube integral bending according to claim 1, characterized in that, The geometric parameters of the complex double-layer tube to be bent include target spatial geometry information, tube length, inner tube radius, outer tube radius, inner and outer layer gap, assembly deviation, and safety gap threshold. The parameters for the multi-bend path include the feeding length, turning angle, bending angle, and bending radius of each bending unit; Machine tool parameters include ground height, bed center position, bed dimensions, bending die center offset, clamping block installation deviation, pressing die installation deviation, and normal process contact exclusion area; The parametric machine tool scene model includes ground height, machine bed center position, machine bed size, bending die center offset, bending die width, clamping block size, clamping block installation deviation, pressing die size, pressing die installation deviation, and tool normal contact exclusion length.

3. The method for anti-interference path planning of complex double-layer tube integral bending according to claim 1, characterized in that, The process of generating candidate paths for both the overall positive bend and the overall reverse bend of the entire complex double-layer pipe includes: The overall bending direction variable of the complex double-layer tube is: in, Indicates the overall positive curve path. Indicates the overall reverse curve path; The overall candidate path is then represented as: when At that time, the overall positive curve candidate path is obtained. : when At that time, the overall reverse bend candidate path is obtained. : in, Indicates the overall candidate path. This indicates the total number of bending processes. Indicates the process number in the reverse sequence. This indicates the feed length of the process in the reverse sequence. This represents the rotation angle about the tube axis in the reverse sequence. Indicates the nominal bending angle in the reverse sequence. This represents the bending radius of the pipe centerline in the reverse sequence. This indicates the process number in the original sequence. This indicates the feed length of the process in the original sequence. This represents the reverse axial rotation angle in the original sequence. This represents the nominal bending angle in the original sequence. This represents the radius of curvature of the centerline in the original sequence.

4. The method for anti-interference path planning of complex double-layer tube integral bending according to claim 1, characterized in that, The entire process of dynamic scanning of the overall positive bend candidate path and the overall reverse bend candidate path, including the feeding stage, pipe transfer stage, and bending stage, is performed, including: During the feeding stage, the position of the double-layer tube along the feeding direction is updated according to the current feeding length; during the tube turning stage, the rotation posture of the double-layer tube around the machine head axis is updated according to the current tube turning angle; during the bending stage, the bending state of the double-layer tube around the bending mold is updated according to the current bending angle and bending radius, gradually forming the corresponding spatial bending segment. The candidate paths for overall positive bends and overall negative bends use the same pipe geometry parameters, the same machine parameters, the same safety clearance requirements, and the same scanning step size. The entire multi-bend pipe uses opposite overall bending directions.

5. The method for anti-interference path planning of complex double-layer tube integral bending according to claim 1, characterized in that, The process of determining whether there is a risk of interference includes: In each scanning substep of the overall positive bend candidate path and the overall negative bend candidate path, the spatial distance between the double-layer tube equivalent spatial envelope model and the machine tool components, bed, ground and formed tube segment is calculated, and the presence of interference risk is determined according to the preset safety clearance requirements. When the safety gap between the double-layer tube and any object being tested is less than the preset safety gap, it is determined that there is an interference risk in the scanning state, and the corresponding bending unit, movement stage, scanning progress, interference object and minimum safety gap are recorded. For the normal contact area between the bending die, clamping block, and pressing die and the pipe fitting, a contact exclusion length is set. Within the contact exclusion length, the contact between the pipe fitting and the working die is judged as normal process contact and is not treated as abnormal interference. The state that exceeds the contact exclusion length and is less than the preset safety gap is judged as an abnormal interference risk. The safe clearance between the complex double-layered pipe and the obstacle is: in, This represents the safe clearance between any capsule unit and an obstacle in the equivalent spatial envelope model of a double-layered tube. In the equivalent spatial envelope model of a double-layered tube, the first... The central line segment of each capsule unit Indicates the first An obstacle model, This represents the minimum distance between the center line segment and the obstacle. Indicates the equivalent outer envelope radius of the double-layer tube; Obstacles include machine tool components, machine bed, ground, pre-formed pipe sections, and non-adjacent pipe sections.

6. The method for anti-interference path planning of complex double-layer tube integral bending according to claim 1, characterized in that, The methods for determining the final bending direction include: When the overall positive bend candidate path meets the safety clearance requirement, while the overall negative bend candidate path does not meet the safety clearance requirement, the overall positive bend path shall be selected. When the overall reverse bending candidate path meets the safety clearance requirement, but the overall forward bending candidate path does not meet the safety clearance requirement, the overall reverse bending path shall be selected. When both the overall positive bend candidate path and the overall negative bend candidate path meet the safety clearance requirements, the path with the larger minimum safety clearance for the entire path shall be selected first. When neither the overall positive bend candidate path nor the overall negative bend candidate path meets the safety clearance requirements, path parameter correction or machine tool parameter adjustment is triggered.

7. The method for anti-interference path planning of complex double-layer tube integral bending according to claim 6, characterized in that, Methods for correcting path parameters or adjusting machine tool parameters include: The path parameters or machine tool parameters are corrected according to the first interference object and the interference stage. The correction includes adjusting at least one of the following: feeding length, tube angle, bending angle, bending radius, bending sequence, fixture installation deviation, machine tool avoidance posture, or safety clearance threshold. After correction, the overall positive bend candidate path and the overall negative bend candidate path are regenerated, and the entire process is scanned again until an interference-resistant bend path that meets the safety clearance requirements is obtained.

8. A complex double-layer pipe integral bending anti-interference path planning system, characterized in that, include: The parameter module is used to obtain the geometric parameters, multi-bend path parameters, and machine tool parameters of the complex double-layer tube to be bent; The modeling module is used to generate candidate paths for the overall positive bend and the overall reverse bend of the entire complex double-layer pipe based on the multi-bend path parameters, establish an equivalent spatial envelope model of the double-layer pipe based on geometric parameters, and establish a parametric machine tool scene model under a fixed machine head reference system based on machine tool parameters. The calculation module is used to perform dynamic scanning of the entire process of the overall positive bending candidate path, the tube turning stage, and the bending stage using the double-layer tube equivalent spatial envelope model and the parameterized machine tool scene model. It calculates the safety gap between the complex double-layer tube and the obstacle, determines whether there is an interference risk, and determines the final bending direction or priority correction object based on the scanning results, and generates an anti-interference path.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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