Aviation casing three-dimensional process model construction method and system based on feature recognition

Abstract

The invention discloses an aviation casing three-dimensional process model construction method and system based on feature recognition, and the method comprises the steps: S1, recognizing manufacturing features in an aviation casing part three-dimensional model, and extracting the feature parameters of the manufacturing features; s2, based on the characteristic parameters, a processing method of the manufacturing characteristics is obtained through intelligent reasoning of a knowledge base; wherein the knowledge base stores a mapping relationship between typical features and processing methods; s3, according to the manufacturing characteristics and the machining method, a process route of the aviation casing part is planned; wherein the process route comprises a plurality of procedures and a sequence thereof; s4, adding the processing method into a corresponding process of the process route to form a process content; and S5, based on the process route and the process content, automatically creating a three-dimensional process model of the aviation casing part. The method has the advantages of high construction efficiency and the like.

Description

Technical Field

[0001] This invention mainly relates to the field of three-dimensional process technology, specifically to a method and system for constructing a three-dimensional process model of an aircraft casing based on feature recognition. Background Technology

[0002] Traditional two-dimensional process design involves creating process cards and describing the process using text and diagrams. However, as manufacturing capabilities improve, product complexity and precision also increase. Two-dimensional processes, lacking three-dimensional models, cannot provide data support for downstream operations (such as CNC programming, inspection programming, and simulation analysis). Therefore, traditional two-dimensional process cards are essentially static graphical and textual process cards, unable to intuitively express dynamic processing, unable to effectively guide the production site, and unable to meet the development requirements of enterprises.

[0003] Currently, CAD software can be used to create 3D process models using its built-in functions, but the operation is difficult and the modeling efficiency is low, resulting in low feasibility of 3D process design. Summary of the Invention

[0004] To address the technical problems existing in the prior art, this invention provides a method and system for constructing a highly efficient 3D process model of an aircraft casing based on feature recognition.

[0005] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows: A method for constructing a 3D process model of an aircraft casing based on feature recognition, comprising the following steps: S1. Identify manufacturing features in the 3D model of the aircraft casing part and extract the feature parameters of the manufacturing features; wherein, the manufacturing features include hole features and casing-specific features, and the feature parameters include geometric dimensions, position and orientation information; S2. Based on the feature parameters extracted in S1, the processing method of the manufacturing feature is obtained through intelligent reasoning using a knowledge base; wherein, the knowledge base stores the mapping relationship between typical features and processing methods; S3. Based on the manufacturing features identified in S1 and the processing method deduced in S2, plan the process route for the aircraft casing part; wherein, the process route includes multiple processes and their sequence; S4. Add the processing method obtained from S2 to the corresponding process of the process route planned in S3 to form process content; S5. Based on the process route planned in S3 and the process content formed in S4, automatically create a three-dimensional process model of the aircraft casing part.

[0006] Preferably, in step S1, the hole type features include at least one of simple hole, through hole, blind hole, countersunk hole, countersunk through hole, and threaded hole; wherein, the feature parameters of the simple hole include the hole diameter, length, bottom cone half angle, and opening chamfer; the feature parameters of the through hole include the hole diameter, length, and bottom / top chamfer; the feature parameters of the blind hole include the hole diameter, length, and opening chamfer; the feature parameters of the countersunk hole include the hole diameter, depth, countersunk diameter, and countersunk depth; the feature parameters of the countersunk through hole include the hole diameter, depth, and countersunk diameter; and the feature parameters of the threaded hole include the hole diameter, depth, relief groove diameter, and thread specification.

[0007] Preferably, in step S1, the casing-specific features include at least one of a reference hole, a contour plane, an inner circular plane, a deep hole, a rotating inner circle, a U-shaped straight groove, and a waist-shaped arc groove; wherein, the feature parameters of the contour plane include the plane's normal and inner contour setting; the feature parameters of the inner circular plane include the inner circle radius and length; the feature parameters of the deep hole include the diameter and depth of the multi-layered hole; the feature parameters of the rotating inner circle include the feature orientation and thread specification; the feature parameters of the U-shaped straight groove include the groove depth, groove length, and groove bottom fillet; and the feature parameters of the waist-shaped arc groove include the large arc diameter, the small arc diameter, and the groove depth.

[0008] Preferably, the specific process for identifying manufacturing features in the 3D model of the aircraft casing part in step S1 is as follows: Set the product model as the currently displayed component. First, obtain the solid object in the product model. Then, obtain all the planes on the solid object. Query all the inner hole edges on the planes and filter out the inner holes that consist of only one circular edge. After obtaining all objects, starting with the inner hole edge, find the cylindrical surface that is adjacent to the plane and has only two edges. Then find the adjacent surface with the other edge of the cylindrical surface, and so on, until a surface that does not meet the characteristics of a hole is found and the process ends. The found combinations of faces are matched and classified with the combinations of hole feature faces, and then hole feature parameters are extracted based on the definition of the hole category.

[0009] Preferably, the specific process of identifying manufacturing features in the 3D model of the aircraft casing part in step S1 is as follows: receiving feature surfaces manually picked up by the user; and extracting corresponding feature parameters based on the geometric information of the feature surfaces.

[0010] Preferably, in step S2, the intelligent reasoning includes: Based on the dimensional requirements in the characteristic parameters, the design intent is converted into process attributes; Based on the typical feature processing methods stored in the knowledge base, the processing method of the manufacturing feature is deduced.

[0011] Preferably, in step S3, planning the process route includes: Based on the manufacturing characteristics, process attributes, and processing methods, the initial process route of a typical part is inferred from the knowledge base. Based on the principles of process planning and process resources, the processing methods are recombined and rearranged to form an optimized process route.

[0012] The present invention also discloses a computer program product, comprising a computer program that, when executed by a processor, performs the steps of the method described above.

[0013] The present invention further discloses a computer-readable storage medium having a computer program stored thereon, the computer program executing the steps of the method described above when run by a processor.

[0014] The present invention also discloses a feature recognition-based system for constructing a three-dimensional process model of an aircraft casing, comprising an interconnected memory and a processor, wherein the memory stores a computer program, and the computer program executes the steps of the method described above when run by the processor.

[0015] Compared with the prior art, the advantages of the present invention are as follows: This invention enables the rapid construction of 3D process models for aircraft casings based on feature recognition through extensive analysis and research of casing feature models. Centered on the designed product, the system identifies manufacturing features in the 3D model of the designed part and employs a knowledge-based design approach to intelligently derive the processing methods for each feature. Then, through human-computer interaction, it generates machining processes for the part. Based on the part model and the process flow, the system automatically creates 3D models for each process step. This method significantly improves the design efficiency of 3D process models for aircraft casings, laying the foundation for 3D process design, CNC programming, inspection programming, and simulation analysis of aircraft casings.

[0016] The method for constructing a three-dimensional process model of an aircraft casing based on feature recognition, as described in this invention, has been applied in a factory and has improved efficiency by approximately 34% compared to creating a three-dimensional process model using the built-in functions of CAD design software. Through its application, process data is extended from process design to downstream programming, processing, and inspection stages using the process model as a carrier, forming the flow and application of process data throughout the entire product lifecycle. This has solidified the foundation for digital and automated manufacturing, shortened the product manufacturing cycle, and saved more management costs. Attached Figure Description

[0017] Figure 1 This is a three-dimensional model of the aircraft casing of the present invention.

[0018] Figure 2The flowchart is a representation of the method for constructing a three-dimensional process model of an aircraft casing according to an embodiment of the present invention.

[0019] Figure 3 The following is a structural diagram of the hole features in the present invention in an embodiment; (a) is a simple hole; (b) is a through hole; (c) is a hole; (d) is a countersunk hole; (e) is a countersunk through hole; (f) is a threaded hole.

[0020] Figure 4 The diagram shows the structure of the casing-specific features in the present invention in an embodiment; (a) is a reference hole; (b) is a contour plane; (c) is an inner circular plane; (d) is a deep hole; (e) is a rotating inner circle; (f) is a U-shaped straight groove; and (g) is a waist-shaped arc groove.

[0021] Figure 5 This is a diagram of the operation interface for constructing the three-dimensional process model of the aircraft casing of the present invention.

[0022] Figure 6 The diagram shows typical features of the present invention; (a) is a hole feature; (b) is a casing-specific feature.

[0023] Figure 7 This is an interface diagram for identifying features in this invention.

[0024] Figure 8 This is an interface diagram showing the addition of a processing method in this invention.

[0025] Figure 9 This is a diagram of the process route planning interface in this invention.

[0026] Figure 10 This is an interface diagram showing the process of adding processing content to the steps in this invention.

[0027] Figure 11 This is a schematic diagram of the process model created in this invention. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0029] like Figure 1 As shown, the serialized parts of the casing are generally composed of various relatively fixed structural combinations. The part in this example is composed of features such as an outer cylindrical body, axial hole, annular groove, radial circular hole, radial elongated hole, eccentric oblique hole, and chamfer / fillet. These features correspond to a typical and mature processing method, so these features can be regarded as typical features.

[0030] Parts composed of typical features can be identified during the process design stage using feature recognition technology. This allows for the definition of processing methods for these typical features and the design of the part's process route. As a result, a part can be quickly decomposed into multiple processes, enabling the rapid creation of process models.

[0031] The rapid design technology for 3D process models of aircraft casings based on feature recognition is developed using Windows 10 64-bit, .NET Framework 4, Visual Studio 2017, and NX11 environment.

[0032] like Figure 5 As shown, the user interface for the rapid design technology of 3D process model of aircraft casing based on feature recognition includes function tabs, function commands, processing feature display area, detailed information and parameter setting area, and process route planning area.

[0033] like Figure 2 As shown, the method for constructing a three-dimensional process model of an aircraft casing based on feature recognition provided in this embodiment of the invention includes the following steps: S1. Identify manufacturing features in the 3D model of the aircraft casing part and extract the feature parameters of the manufacturing features; like Figure 6 As shown, by analyzing typical parts, typical manufacturing features are summarized and defined, including hole features and casing-specific features; feature parameters include at least geometric dimensions, position, and orientation information, such as... Figure 7 As shown; S2. Based on the feature parameters extracted in S1, the processing method of manufacturing features is obtained through intelligent reasoning using a knowledge base; wherein, the knowledge base stores the mapping relationship between typical features and processing methods; This step translates design intent into process requirements. For the dimensional requirements of the identified features (design requirements), the design requirements are analyzed to transform them into the process attributes of the features, such as... Figure 8 As shown.

[0034] S3. Based on the manufacturing features identified in S1 and the processing methods inferred in S2, plan the process route for the aircraft casing parts; wherein, the process route includes multiple processes and their sequence; Specifically, based on processing characteristics and characteristic attributes (process requirements), the process route for typical parts is inferred from the knowledge base. According to the basic principles of process planning and process resources, the processing methods for the characteristics are recombined and arranged to form the processing route for the part, such as... Figure 9 As shown.

[0035] S4. Add the processing method obtained from the reasoning in S2 to the corresponding process in the process route planned in S3 to form the process content; Specifically, the machining methods from the feature tree are added to the corresponding processes. The order in which the machining methods for each process are added is reflected in the modeling history in the process model part navigator, which can be used as a reference for the machining sequence in subsequent CAM programming. For example... Figure 10 As shown.

[0036] S5. Based on the process route planned in S3 and the process content formed in S4, automatically create a three-dimensional process model of the aircraft casing part.

[0037] like Figure 11 As shown, intermediate process diagrams (process drawings or 3D process models) make the description of processes more intuitive and accurate, serving as an important auxiliary representation in the process. In 3D processes, the process model is not only a form of representation but also a crucial component of process data. Process models can also be used for dynamic simulation of machining processes, performance analysis of machining processes, virtual machining scenarios, digital inspection, and other reference-based simulation designs.

[0038] Specifically, the hole-type feature supports both automatic recognition and human-computer interaction recognition, as follows: 1. Simple hole Feature structure: It includes a cylindrical surface and a conical base surface; the opening of the hole may also have a conical surface indicating a chamfer, such as... Figure 3 As shown in (a); For simple hole types, the bottom of the cylindrical surface is adjacent to a conical surface, coaxial and the large end diameter is the same as the cylindrical surface diameter. The opening may also have an adjacent conical surface, coaxial and the small end diameter is the same as the cylindrical surface.

[0039] Its data structure is as follows: public class SimpleHoleParam { public List <face>FaceAll = new List <face>(); public Point3d Origin; / / Origin (center point of the hole bottom) public Vector3d Direction; / / Hole direction public double Diameter; / / Diameter of the hole public double Length; / / Length of the hole public double HalfAngle; / / Half angle of the cone at the bottom of the hole public double HoleChamfer; / / Hole chamfer public double ChamferfAngle; / / Chamfer angle of the orifice public string ThreadSize; / / Thread size public double ThreadDepth; / / Thread depth } 2. Through hole Feature structure: Contains only a cylindrical surface; the opening and bottom of the hole may also have a conical surface representing a chamfer, such as... Figure 3 As shown in (b); For through-hole types, the cylindrical opening and bottom may be adjacent to a conical surface, coaxial, and the diameter of the smaller end is the same as the diameter of the cylindrical surface.

[0040] Its data structure is as follows: public class RoundHoleParam { public List <face>FaceAll = new List <face>(); public double Diameter; / / Diameter of the hole public Vector3d Direction; / / Hole direction public double Length; / / Length of the hole public Point3d Origin; / / Origin (center point of the hole bottom) public double BotChamfer; / / Botchamfer public double BotChamferfAngle; / / Bottom chamfer public double TopChamfer; / / Top chamfer public double TopChamferfAngle; / / Top chamfer public string ThreadSize; / / Thread size public double ThreadDepth; / / Thread depth } 3. Hole Feature structure: It includes a cylindrical surface and a flat bottom surface; the opening of the hole may also have a conical surface indicating a chamfer, such as... Figure 3 As shown in (c); For blind hole type, the bottom of the cylindrical surface is adjacent to a plane with only one circular edge, and the diameter of the circular edge is the same as the diameter of the cylindrical surface. The opening may also have an adjacent conical surface, which is coaxial and the diameter of the small end is the same as the cylindrical surface.

[0041] Its data structure is as follows: public class SimpleHoleParam { public List <face>FaceAll = new List <face>(); public Point3d Origin; / / Origin (center point of the hole bottom) public Vector3d Direction; / / Hole direction public double Diameter; / / Diameter of the hole public double Length; / / Length of the hole public double HalfAngle; / / Half angle of the cone at the bottom of the hole public double HoleChamfer; / / Hole chamfer public double ChamferfAngle; / / Chamfer angle of the orifice public string ThreadSize; / / Thread size public double ThreadDepth; / / Thread depth } 4. Countersunk hole Characteristic structure: The hole portion, like a simple hole, includes a cylindrical surface and a conical bottom surface. The countersunk head consists of a cylindrical surface and a flat bottom surface. The opening of the countersunk head may also have a conical surface indicating a chamfer, such as... Figure 3 As shown in (d); For countersunk hole types, the bottom of the cylindrical surface of the hole is adjacent to a conical surface, coaxial, and the diameter of the larger end is the same as the diameter of the cylindrical surface. The bottom of the cylindrical surface of the countersunk part is adjacent to a plane, which has only two circular edges. The diameter of the smaller circle is the same as the hole, and the diameter of the larger circle is the same as the countersunk diameter. There may also be an adjacent conical surface at the opening, coaxial, and the diameter of the smaller end is the same as the diameter of the countersunk cylindrical surface.

[0042] Its data structure is as follows: public class CounterBoredHoleParam { public List <face>FaceAll = new List <face>(); public Point3d Origin; / / Origin (center point of the hole bottom) public Vector3d Direction; / / Hole direction public double Diameter; / / Diameter of the hole public double Depth; / / Depth of the hole public double HalfAngle; / / Half angle of the cone at the bottom of the hole public double HoleChamfer; / / Hole chamfer public double HoleChamferAngle; / / Hole chamfer angle public double BigDiam; / / Countersunk diameter public double CounterBoredDepth; / / Counterbored depth public double CounterBoredBlendRadius; / / Counterbored Blend Radius; / / Counterbored Blend Radius public double CounterBoredChamfer; / / Counterbored Chamfer public double CounterBoredChamferAngle; / / Counterbored Chamfer Angle public string ThreadSize; / / Thread size public double ThreadDepth; / / Thread depth } 5. Countersunk through hole Characteristic structure: The hole portion, like a through hole, consists of only a cylindrical surface. The countersunk head is divided into a cylindrical surface and a flat bottom surface. The opening of the countersunk head and the bottom of the hole may also have a conical surface indicating a chamfer, such as... Figure 3 As shown in (e); For countersunk through holes, the bottom of the cylindrical surface of the hole may be adjacent to a conical surface, coaxial and with the small end diameter the same as the cylindrical surface diameter. The bottom of the cylindrical surface of the countersunk part is adjacent to a plane with only two circular edges. The small circle diameter is the same as the hole diameter, and the large circle diameter is the same as the countersunk diameter. There may also be an adjacent conical surface at the opening, coaxial and with the small end diameter the same as the countersunk cylindrical surface.

[0043] Its data structure is as follows: public class CounterBoredThroughHoleParam { public List <face>FaceAll = new List <face>(); public Point3d Origin; / / Origin (center point of the hole bottom) public Vector3d Direction; / / Hole direction public double Diameter; / / Diameter of the hole public double Depth; / / Depth of the hole public double HoleChamfer; / / Hole chamfer public double HoleChamferAngle; / / Hole chamfer angle public double BigDiam; / / Countersunk diameter public double CounterBoredDepth; / / Counterbored depth public double CounterBoredBlendRadius; / / Counterbored Blend Radius; / / Counterbored Blend Radius public double CounterBoredChamfer; / / Counterbored Chamfer public double CounterBoredChamferAngle; / / Counterbored Chamfer Angle public string ThreadSize; / / Thread size public double ThreadDepth; / / Thread depth } 6. Threaded hole Characteristic structure: The hole portion, like a simple hole, includes a cylindrical surface and a conical bottom surface. The relief groove portion consists of a cylindrical surface and a conical bottom surface, and the opening of the relief groove may also have a conical surface indicating a chamfer. For example... Figure 3 As shown in (f); For threaded hole types, the bottom of the cylindrical surface of the hole may be adjacent to a conical surface, coaxial and with the small end diameter the same as the diameter of the cylindrical surface. The bottom of the cylindrical surface of the relief groove is adjacent to a conical surface, which has two sides, a small end diameter the same as the hole diameter and a large end diameter the same as the relief groove diameter. There may also be an adjacent conical surface at the opening, coaxial and with the small end diameter the same as the cylindrical surface of the relief groove.

[0044] Its data structure is as follows: public class ThreadedHoleParam { public List <face>FaceAll = new List <face>(); public Point3d Origin; / / Origin (center point of the hole bottom) public Vector3d Direction; / / Hole direction public double Diameter; / / Diameter of the hole public double Depth; / / Depth of the hole public double HalfAngle; / / Half angle of the cone at the bottom of the hole public double ReliefDiam; / / Diameter of the relief groove public double ReliefDepth; / / Depth of the relief groove public double ReliefHalfAngle; / / Half angle of the cone at the bottom of the relief groove public double Chamfer; / / Chamfering at the mouth public double ChamferAngle; / / Chamfer angle of the mouth public string ThreadSize; / / Thread size public double ThreadDepth; / / Thread depth } Specifically, the chassis-specific features only support human-machine interaction recognition, including: 1. Reference hole Same as through hole, such as Figure 4 As shown in (a).

[0045] 2. Contour Plane Composed of only a single plane, using the outer contour on the plane as the boundary of features, supporting the exclusion of holes, and preserving the maximum inner contour, such as... Figure 4 As shown in (b).

[0046] Its data structure is as follows: public class OutlineExtrudePlaneParam { public List <face>FaceAll = new List <face>(); public Vector3d ExtrudeDirection; / / Normal to the plane public int InnerEnum = 0; / / Inner contour setting } 3. Inner circular plane The structure is similar to a flat-bottomed hole, but the difference is that the bottom surface can have holes, such as... Figure 4 As shown in (c).

[0047] Its data structure is as follows: public class InnerCircleWithHoleParam { public List <face>FaceAll = new List <face>(); public Point3d Origin; / / Origin (center point of the hole bottom) public Vector3d Direction; / / Direction public double Radius; / / Inner circle radius public double Length; / / Length public double BlendRadius; / / Hole bottom rounding radius } 4.Deep hole Composed of one or more simple holes, supporting up to three layers, such as Figure 4 As shown in (d).

[0048] Its data structure is as follows: public class DeepHoleParam { public List <face>FaceAll = new List <face>(); public Point3d _origin; public Vector3d _direction; / / Hole direction public double _hole1Diam; / / Diameter of the hole public double _hole1Depth; / / Depth of the hole public double _hole2Diam; / / Diameter of the hole public double _hole2Depth; / / Depth of the hole public double _hole3Diam; / / Diameter of the hole public double _hole3Depth; / / Depth of the hole } 5. Rotation of the inner circle An inner circle feature composed of multiple cylindrical surfaces, conical surfaces, and planes, such as Figure 4 As shown in (e).

[0049] Its data structure is as follows: public class InnerCircleRotationParam { public List <face>FaceAll = new List <face>(); public UGCSYSData sectionCsys; / / Feature orientation public double _threadHoleDim; / / Diameter of threaded hole public string _threadSize; / / Thread specification public double _threadDepth; / / Thread depth } 6. U-shaped straight groove The groove-shaped feature, composed of three planes, supports rounded bottom corners, such as... Figure 4 As shown in (f).

[0050] Its data structure is as follows: public class U_LineGrooveParam { public List <face>FaceAll = new List <face>(); public Vector3d DirDepth; / / Length direction public Vector3d DirWidth; / / Width direction public double GrooveDepth; / / Groove depth public double GrooveLength; / / Groove length public double GrooveRadius; / / Groove bottom rounded corners public double GrooveWidth; / / Groove width public double LengthOffset; / / Length offset public Point3d Origin; / / Starting position of the slot } 7. Waist-shaped arc groove A waist-shaped feature composed of four consecutive tangent arc surfaces, two of which are concentric (parallel), and the other two are tangent to the first two surfaces simultaneously, such as... Figure 4 As shown in (g).

[0051] Its data structure is as follows: public class Waist_ArcGrooveParam { public List <face>FaceAll = new List <face>(); public double BotOffset; / / Bot offset public Vector3d Direction; / / Direction of the slot public Point3d End; / / The endpoint (center) of the groove's length direction. public double GrooveDepth; / / Groove depth public double LargeArcDiam; / / Large arc diameter public double MinorArcDiam; / / Minor arc diameter public Point3d Origin; / / Start point (center) of the groove depth direction public Point3d Start; / / Starting point (center) of the groove's length direction } Specifically, in step S1, the process of identifying manufacturing features in the 3D model of the aircraft casing part is as follows: Set the product model as the currently displayed component. First, obtain the solid object in the product model. Then, obtain all the planes on the solid object. Query all the inner hole edges on the planes and filter out the inner holes that consist of only one circular edge. After obtaining all objects, starting with the inner hole edge, find the cylindrical surface that is adjacent to the plane and has only two edges. Then find the adjacent surface with the other edge of the cylindrical surface, and so on, until a surface that does not meet the characteristics of a hole is found and the process ends. The found combinations of faces are matched and classified with the combinations of hole feature faces, and then hole feature parameters are extracted based on the definition of the hole category.

[0052] In other embodiments, the user directly and manually picks the face defined by the corresponding feature, and the program extracts the corresponding feature parameters based on the geometric information of the face.

[0053] This invention enables the rapid construction of 3D process models for aircraft casings based on feature recognition through extensive analysis and research of casing feature models. Centered on the designed product, the system identifies manufacturing features in the 3D model of the designed part and employs a knowledge-based design approach to intelligently derive the processing methods for each feature. Then, through human-computer interaction, it generates machining processes for the part. Based on the part model and the process flow, the system automatically creates 3D models for each process step. This method significantly improves the design efficiency of 3D process models for aircraft casings, laying the foundation for 3D process design, CNC programming, inspection programming, and simulation analysis of aircraft casings.

[0054] The method for constructing a three-dimensional process model of an aircraft casing based on feature recognition, as described in this invention, has been applied in a factory and has improved efficiency by approximately 34% compared to creating a three-dimensional process model using the built-in functions of CAD design software. Through its application, process data is extended from process design to downstream programming, processing, and inspection stages using the process model as a carrier, forming the flow and application of process data throughout the entire product lifecycle. This has solidified the foundation for digital and automated manufacturing, shortened the product manufacturing cycle, and saved more management costs.

[0055] The present invention also discloses a computer program product, comprising a computer program that, when executed by a processor, performs the steps of the method described above.

[0056] The present invention further discloses a computer-readable storage medium having a computer program stored thereon, the computer program executing the steps of the method described above when run by a processor.

[0057] The present invention also discloses a feature recognition-based system for constructing a three-dimensional process model of an aircraft casing, comprising an interconnected memory and a processor, wherein the memory stores a computer program, and the computer program executes the steps of the method described above when run by the processor.

[0058] The products, media, and systems of the present invention, corresponding to the methods described above, also possess the advantages described above.

[0059] The present invention can implement all or part of the processes in the methods of the above embodiments, or it can be implemented by hardware related to computer program instructions. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, it can implement the steps of the above method embodiments. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer-readable storage medium includes: any entity or device capable of carrying computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. The memory is used to store computer programs and / or modules. The processor implements various functions by running or executing the computer programs and / or modules stored in the memory, and by calling data stored in the memory. The memory may include high-speed random access memory, as well as non-volatile memory, such as hard disks, RAM, plug-in hard disks, smart media cards (SMC), secure digital (SD) cards, flash cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0060] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.< / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face> < / face>

Claims

1. A method for constructing a three-dimensional process model of an aircraft casing based on feature recognition, characterized in that, Including the following steps: S1. Identify manufacturing features in the 3D model of the aircraft casing part and extract the feature parameters of the manufacturing features; wherein, the manufacturing features include hole features and casing-specific features, and the feature parameters include geometric dimensions, position and orientation information; S2. Based on the feature parameters extracted in S1, the processing method of the manufacturing feature is obtained through intelligent reasoning using a knowledge base; wherein, the knowledge base stores the mapping relationship between typical features and processing methods; S3. Based on the manufacturing features identified in S1 and the processing method deduced in S2, plan the process route for the aircraft casing part; wherein, the process route includes multiple processes and their sequence; S4. Add the processing method obtained from S2 to the corresponding process of the process route planned in S3 to form process content; S5. Based on the process route planned in S3 and the process content formed in S4, automatically create a three-dimensional process model of the aircraft casing part.

2. The method for constructing a three-dimensional process model of an aircraft casing based on feature recognition according to claim 1, characterized in that, In step S1, the hole type features include at least one of simple hole, through hole, blind hole, countersunk hole, countersunk through hole, and threaded hole; wherein, the feature parameters of the simple hole include the hole diameter, length, bottom cone half angle, and opening chamfer; the feature parameters of the through hole include the hole diameter, length, and bottom / top chamfer; the feature parameters of the blind hole include the hole diameter, length, and opening chamfer; the feature parameters of the countersunk hole include the hole diameter, depth, countersunk diameter, and countersunk depth; the feature parameters of the countersunk through hole include the hole diameter, depth, and countersunk diameter; and the feature parameters of the threaded hole include the hole diameter, depth, relief groove diameter, and thread specification.

3. The method for constructing a three-dimensional process model of an aircraft casing based on feature recognition according to claim 1, characterized in that, In step S1, the casing-specific features include at least one of the following: a reference hole, a contour plane, an inner circular plane, a deep hole, a rotating inner circle, a U-shaped straight groove, and a waist-shaped arc groove; wherein, the feature parameters of the contour plane include the plane's normal direction and inner contour setting; the feature parameters of the inner circular plane include the inner circle radius and length; the feature parameters of the deep hole include the diameter and depth of the multi-layered hole; the feature parameters of the rotating inner circle include the feature orientation and thread specification; the feature parameters of the U-shaped straight groove include the groove depth, groove length, and groove bottom fillet radius; and the feature parameters of the waist-shaped arc groove include the large arc diameter, small arc diameter, and groove depth.

4. The method for constructing a three-dimensional process model of an aircraft casing based on feature recognition according to claim 1, 2, or 3, characterized in that, The specific process for identifying manufacturing features in the 3D model of the aircraft casing part in step S1 is as follows: Set the product model as the currently displayed component. First, obtain the solid object in the product model. Then, obtain all the planes on the solid object. Query all the inner hole edges on the planes and filter out the inner holes that consist of only one circular edge. After obtaining all objects, starting with the inner hole edge, find the cylindrical surface that is adjacent to the plane and has only two edges. Then find the adjacent surface with the other edge of the cylindrical surface, and so on, until a surface that does not meet the characteristics of a hole is found and the process ends. The found combinations of faces are matched and classified with the combinations of hole feature faces, and then hole feature parameters are extracted based on the definition of the hole category.

5. The method for constructing a three-dimensional process model of an aircraft casing based on feature recognition according to claim 1, 2, or 3, characterized in that, The specific process of identifying manufacturing features in the 3D model of the aircraft casing part in step S1 is as follows: receiving the feature surfaces manually picked by the user; extracting the corresponding feature parameters based on the geometric information of the feature surfaces.

6. The method for constructing a three-dimensional process model of an aircraft casing based on feature recognition according to claim 1, 2, or 3, characterized in that, In step S2, the intelligent reasoning includes: Based on the dimensional requirements in the characteristic parameters, the design intent is converted into process attributes; Based on the typical feature processing methods stored in the knowledge base, the processing method of the manufacturing feature is deduced.

7. The method for constructing a three-dimensional process model of an aircraft casing based on feature recognition according to claim 1, 2, or 3, characterized in that, In step S3, planning the process route includes: Based on the manufacturing characteristics, process attributes, and processing methods, the initial process route of a typical part is inferred from the knowledge base. Based on the principles of process planning and process resources, the processing methods are recombined and rearranged to form an optimized process route.

8. A computer program product, comprising a computer program, characterized in that, The computer program is executed by the processor to perform the steps of the method as described in any one of claims 1-7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program, when run by a processor, performs the steps of the method as described in any one of claims 1-7.

10. A system for constructing a three-dimensional process model of an aircraft casing based on feature recognition, comprising an interconnected memory and a processor, wherein the memory stores a computer program, characterized in that, The computer program, when run by a processor, performs the steps of the method as described in any one of claims 1-7.

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