CN104502527A - Automatic detection method for defects of airplane structural-member model - Google Patents

Abstract

The invention discloses an automatic detection method for defects of an airplane structural-member model, and the method is used to solves the technological problem that a conventional detection method is low in accuracy. The technical scheme comprises that three-dimension model defects are classified in detail according to the characteristics of the defects in practical numerical-control processing, and the generation mechanism of the three-dimension model defects and the characteristics of the three-dimension model defects in a geometrical layer and a topological layer are analyzed, and a corresponding determination rule is concluded and extracted for identifying defects. Aiming at a to-be tested structural-member model, the geometrical parameters at three levels of surface, edge and point and the topological attributes of the model are extracted, and different attribute parameters of multiple surfaces, edges or points in a local structure are mixed together for together representing the local structure defects. The attribute parameters extracted from the to-be detected three-dimension model are matched with the defect determination rule, and is matched, the fact that the model has the kind of defect is shown. The method combines the structural relation between the three-dimension model defects and the intersection characteristics, and accurately identifies the three-dimension model defect structure according to conditions.

Description

Aircraft structure model defect automatic testing method

Technical field

The present invention relates to a kind of three-dimensional model detection method, particularly relate to a kind of aircraft structure model defect automatic testing method.

Background technology

Document " Blend recognition algorithm and applications [C] .Proeeeding of the sixth ACMsymposium on Solid modeling and applications, 2001:99-108. " discloses a kind of Blend Feature Recognition algorithm produced based on roller ball technology.The method, by the B reps (B-rep) of model, derives the order that Interim creates in a model, helps user to understand the design idea of model.Simultaneously, a mixing identification module is created in feature identification storehouse, Interim and topology, geometry and correlation parameter is identified in a grid formation in the model of complex structure, with the requirement of modelling for criterion, consider the Interim identified, the local feature meeting specified conditions is considered as model defect.Method described in document by carrying out discriminance analysis to the partial structurtes that design a model, excavates corresponding defect, does not have to carry out sorting out, defining for three-dimensional CAD model defect common in actual digital control processing specially, and engineer applied is poor; Identifying is analyzed mainly for the project organization of Interim and parameter, and do not relate to the reciprocation of associated features in defect and model, accuracy rate is not high; The many subjective judgements according to people of recognition methods in addition, undefined relevant criterion, causes computer recognizing efficiency not high.

According to statistics, Interim defect accounts for more than 70% of aircraft structure model defect, and especially at complicated vallecular cavity place, Interim ratio of defects is higher.For this problem of model defect, probe into a kind of Theories and methods detecting aircraft structure model defect, and develop a set of automatic checkout system, quick numerical control journey is realized to Aviation Enterprise and is composed of important realistic meaning.

Summary of the invention

In order to overcome the low deficiency of existing detection method accuracy rate, the invention provides a kind of aircraft structure model defect automatic testing method.Three-dimensional model defect is carried out exhaustive division according to the feature in each comfortable actual number control processing by the method, to three-dimensional model defect produce mechanism and analyze in the characteristic of geometrical layers and topological layer, conclude and extract corresponding decision rule, be applied to the identification of defect.For Structural Part Model to be detected, extract its face, the geometric parameter of limit and point three levels and topological attribute, the different genera Parameter fusion of multiple in partial structurtes, limit or point is symbolized this partial structurtes defect together.The property parameters extracted in three-dimensional model to be detected is mated with determining defects rule, if coupling, then shows to there is such defect in model.The method, in conjunction with the structural relation between three-dimensional model defect and intersecting features, can identify qualified three-dimensional model defect sturcture exactly.

The technical solution adopted for the present invention to solve the technical problems is: a kind of aircraft structure model defect automatic testing method, is characterized in adopting following steps:

The mechanism that step one, logarithmic mode defect produce and its carry out analyzing, concluding and extract corresponding decision rule in the characteristic of geometrical layers and topological layer, and be applied to the identification of defect.For new digital-to-analogue defect, whether belong to existing defect type according to its feature structurally, if do not belong to, then need to formulate its corresponding decision rule.

Step 2, for Structural Part Model to be detected, extract its face, the geometric parameter of limit and point three levels and topological attribute.For face: the concavity and convexity comprising the type in face, the area in face, the directivity in face and face; For limit: the belongingness comprising the type on limit, the length on limit, concavity and convexity and limit; For point: the belongingness comprising concavity and convexity a little and point.

Step 3, the property parameters extracted in digital-to-analogue to be detected to be mated with determining defects rule, if match, then show to there is such defect in digital-to-analogue.

Definition transition planar defect type: leak rounding, end R is discontinuous, transition parameter is inconsistent, variation, broken and side R be section.The decision method of all kinds of defect is the combination of each rule above-mentioned, and even model partial structurtes meet above-mentioned one or more rule, are namely considered as defect.There are two kinds of situations in the decision rule of defect as discontinuous in end R: even partial structurtes meet the judgement of rule 3, to be then considered as end R discontinuous for this structure; If partial structurtes meet the judgement of regular 3 Sum fanction 4 simultaneously, then this structure end R of being considered as parameter inconsistent is discontinuous.

Rule 1: if the plane f calculated _irelative area be less than a certain threshold value, then plane f _ifor broken plane, namely

$s_{\mathrm{pi}}=\frac{s_i}{\underset{s_k\&Subset;\mathrm{\&Omega;}}{\mathrm{\&Sigma;}}{s}_k+s_i}<\mathrm{\&delta;}---\left(1\right)$

In formula, s _pirepresent plane f _irelative area, δ represents the threshold value of regulation, s _ifor the area of plane fi a certain in model, Ω represents the set in this plane all of its neighbor face.

Rule 2: plane f _ithe common edge being adjacent face is concave edge, then plane f _ifor concave edge face, namely

$\left\{\begin{array}{c}{f}_i\&cap;f_p=e_{\mathrm{concave}}\\ f_p\&Element;\mathrm{\&Omega;}\end{array}\right.---\left(2\right)$

In formula, f _prepresent plane f _iadjacent surface, e _concavethe intersection on expression two sides is concave edge.

Rule 3: certain transition plane f in transition face ring _ithe common edge of the transition face be adjacent is concave edge, then this transition face ring is discontinuous or end R is discontinuous, namely

In formula, represent plane f _ithe set of transition face ring, f _jrepresent plane f _ia certain transition face.

Rule 4: the transition face ring of certain basal plane association in transition face parameter inconsistent, then this transition face ring parameter is inconsistent, namely

$\left\{\begin{array}{c}{r}_{\mathrm{fi}}\&NotEqual;r_{\mathrm{fj}}\\ r_{\mathrm{fi}}\&Element;\{r_{f1},r_{f2},...r_{\mathrm{fn}}\}\\ r_{\mathrm{fj}}\&Element;\{r_{f1},r_{f2},...r_{\mathrm{fn}}\}\\ i\&NotEqual;j\end{array}\right.---\left(4\right)$

Wherein, F represents basal plane, i.e. the web surface of part, { r _f1, r _f2... r _fnfor basal plane F associate transition face ring in each transition face { f ₁, f ₂... f _ncorresponding to transition parameter.

Rule 5: basal plane F and the transition face ring associated by it middle transition face f _icommon edge should be straight line and arc-shaped edges, and the radius of arc-shaped edges is identical.When transition face generation local variations, transition face f _ifor multiple broken and arc-shaped edges is split into the different circular arc of multistage radius and curve, using arc radius value as the rule judging transition face local variations, this rule is also judge to cause transition face as the criterion of broken by local variations, namely

$\left\{\begin{array}{c}F\&cap;f_i=e_{\mathrm{Arci}}\\ r_{\mathrm{Arci}}\&NotEqual;r_{\mathrm{Arcj}}\\ r_{\mathrm{Arci}}\&Element;\{r_{\mathrm{Arc}1},r_{\mathrm{Arc}2},...r_{\mathrm{Arcn}}\}\\ r_{\mathrm{Arcj}}\&Element;\{r_{\mathrm{Arc}1},r_{\mathrm{Arc}2},...r_{\mathrm{Arcn}}\}\\ i\&NotEqual;j\end{array}\right.---\left(5\right)$

In formula, e _arcand e _curverepresent multi-section circular arc set and the collection of curves of composition common edge, r _arcrepresent end R arc radius, { r _arc1, r _arc2... r _arcnrepresent circular arc e _arcarc radius value corresponding to set.

Rule 6: as transition face f _iwhen the common edge being point cantact or transition face and basal plane with basal plane F is straight line, the transition face f calculated by formula (2) _irelative area be less than a certain threshold value, then transition face f _ifor broken, namely

In formula, V _vertexrepresent two sides common intersection, e _linerepresent that two sides intersection is straight line, s _firepresent f _irelative area, σ represent regulation broken scope threshold value.

Rule 7: side fillet is section, then have common edge between the fillet of side;

$\left\{\begin{array}{c}{f}_{\mathrm{ci}}\&cap;f_{\mathrm{cj}}=e\\ f_{\mathrm{ci}}\&Element;\{f_{c1},f_{c2},...f_{\mathrm{cn}}\}\\ f_{\mathrm{cj}}\&Element;\{f_{c1},f_{c2},...f_{\mathrm{cn}}\}\\ i\&NotEqual;j\end{array}\right.---\left(7\right)$

Wherein, { f _c1, f _c2... f _cnbe side fillet set, e is the common edge between the fillet of two sides.

Rule 8: the supporting surface f of transverse holes _iperpendicular to basal plane, and supporting surface is made up of plural ring, i.e. an outer shroud and multiple inner ring, if the limit number of certain inner ring is 2 and is chimb, then shows that this supporting surface comprises transverse holes, namely

$\left\{\begin{array}{c}{f}_i\&perp;F\\ {\mathrm{Count}}_{\mathrm{OutLoop}}=1\\ {\mathrm{Count}}_{\mathrm{InLoop}}\&GreaterEqual;1\\ \mathrm{InLoop}=e_{\mathrm{Convex}1}+e_{\mathrm{Convex}2}\end{array}\right.---\left(8\right)$

In formula, OutLoop represents supporting surface outer shroud, and InLoop represents supporting surface inner ring, e _convexthe side attribute of expression InLoop is chimb.

Rule 9: seam and Remained mass decision rule; Seam and Remained mass cross the micro-structure cutting or owe to cut generation in modeling process, so the face forming this micro-structure is broken and is concave edge face, that is:

Rule 1+ rule 2:=seam or Remained mass (9)

Based on the transition face parameter extraction of colour code.First traversal history operation tree obtains all blending operations, to each blending operation:

Step 1, extract the parameter that this blending operation comprises, recording parameters;

Step 2, by corresponding to this blending operation transition face dyeing, record dye number;

Step 3, will the data structure of blending operation name, parameter and dye number be comprised stored in chain Table A.

Then the transition face in model is obtained, for each transition face:

Step 4, obtain the color value of this transition face;

Element in step 5, ergodic chain Table A, it is right to be carried out by the dye number of element in the color value of transition face and chained list, if to upper, then the parameter in this element is the parameter of this transition face, extracts parameter value.

Rule matching algorithm:

Input: aircraft structure three-dimensional CAD model and reference vector;

Export: dissimilar model defect;

Plane in step 1, extraction model and transition face, respectively stored in plane chained list and transition face chained list;

Step 2, traversal plane chained list, each plane is analyzed, and by the decision principle judgment models of seam and Remained mass whether containing seam with or Remained mass, if have, then be deposited in the chained list of seam Remained mass data structure, and the face mark of regular 1 Sum fanction 2 will be met simultaneously in plane chained list;

Step 3, traversal plane chained list, do not having to find out basal plane in identified plane, carried out from low to high sorting by basal plane and stored in basal plane chained list, identify processed face mark in plane chained list simultaneously according to reference vector direction;

Step 4, traversal basal plane chained list, for each basal plane, transition face ring or the expansion transition face ring of associated is found out in transition face chained list, form a basal plane ring, and stored in comprising in the chained list of basal plane and transition face data structure, claim this chained list to be basal plane loop chain table, in transition face chained list, identify processed transition face simultaneously;

Step 5, traversal basal plane loop chain table, for each element in chained list, analyze the basal plane ring in this element, and judge one by one according to the decision principle of transition face defect, by defective basal plane ring stored in comprising in the chained list of basal plane, transition face and type of error data structure, this chained list is claimed to be defect basal plane loop chain table;

Whether step 6, traversal plane chained list, contain transverse holes by the decision principle judgment models of transverse holes, if having, be then deposited in the chained list of transverse holes data structure.

The invention has the beneficial effects as follows: three-dimensional model defect is carried out exhaustive division according to the feature in each comfortable actual number control processing by the method, to three-dimensional model defect produce mechanism and analyze in the characteristic of geometrical layers and topological layer, conclude and extract corresponding decision rule, be applied to the identification of defect.For Structural Part Model to be detected, extract its face, the geometric parameter of limit and point three levels and topological attribute, the different genera Parameter fusion of multiple in partial structurtes, limit or point is symbolized this partial structurtes defect together.The property parameters extracted in three-dimensional model to be detected is mated with determining defects rule, if coupling, then shows to there is such defect in model.The method, in conjunction with the structural relation between three-dimensional model defect and intersecting features, have identified qualified three-dimensional model defect sturcture exactly.

Below in conjunction with the drawings and specific embodiments, the present invention is elaborated.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of aircraft structure model defect automatic testing method of the present invention.

Fig. 2 is the inventive method transition face defect and decision rule schematic diagram.

Fig. 3 is model defect detection example schematic diagram.

Embodiment

With reference to Fig. 1-3.Aircraft structure model defect automatic testing method concrete steps of the present invention are as follows:

1. determining defects Rule Extraction.The mechanism that logarithmic mode defect produces and its carry out analyzing, concluding and extract corresponding decision rule in the characteristic of geometrical layers and topological layer, and be applied to the identification of defect.For new digital-to-analogue defect, whether belong to existing defect type according to its feature structurally, if do not belong to, then need to formulate its corresponding decision rule.

2. simulation parameters extracts with comprehensive.For Structural Part Model to be detected, extract its face, limit, the geometric parameter of point three levels and topological attribute.For face: comprise the type (basal plane, transition face and other class profile) in face, the area in face, the directivity in face and concavity and convexity; For limit: the belongingness comprising the type (straight line, arc-shaped edges and other curved side) on limit, the length on limit, concavity and convexity and limit; For point: the belongingness comprising concavity and convexity a little and point.The property parameters of single face, limit or point can not symbolize the defect of a certain partial structurtes, needs the different genera Parameter fusion of multiple in these partial structurtes, limit or point just can symbolize this partial structurtes defect together.

3. rule matching algorithm.The property parameters extracted in digital-to-analogue to be detected is mated with determining defects rule, if match, then shows to there is such defect in digital-to-analogue.

The present embodiment defines common transition face defect type: leak rounding, end R is discontinuous, transition parameter is inconsistent, variation, broken and side R be section.The decision method of all kinds of defect is the combination of each rule above-mentioned, and even model partial structurtes meet above-mentioned one or more rule, are namely considered as defect.There are two kinds of situations in the decision rule of defect as discontinuous in end R: even partial structurtes meet the judgement of rule 3, then this structure is considered as end R discontinuous (parameter is consistent); If partial structurtes meet the judgement of regular 3 Sum fanction 4 simultaneously, then this structure end R of being considered as parameter inconsistent is discontinuous.

The mechanism produced according to above-mentioned model defect and the feature extraction on geometry and topology thereof go out following rule:

Rule 1: if the plane f calculated _irelative area be less than a certain threshold value, then plane f _ifor broken plane, namely

$s_{\mathrm{pi}}=\frac{s_i}{\underset{s_k\&Subset;\mathrm{\&Omega;}}{\mathrm{\&Sigma;}}{s}_k+s_i}<\mathrm{\&delta;}---\left(1\right)$

In formula, s _pirepresent plane f _irelative area, δ represents the threshold value of regulation, s _ifor plane f a certain in model _iarea, Ω represents the set in this plane all of its neighbor face (not comprising transition face).

Rule 2: certain face f _ithe common edge that (not containing transition face) is adjacent face is concave edge, then face f _ifor concave edge face, namely

$\left\{\begin{array}{c}{f}_i\&cap;f_p=e_{\mathrm{concave}}\\ f_p\&Element;\mathrm{\&Omega;}\end{array}\right.---\left(2\right)$

In formula, f _prepresent f _iadjacent surface, e _concavethe intersection on expression two sides is concave edge.

Rule 3: certain transition face f in transition face ring _ithe common edge of the transition face be adjacent is concave edge, then this transition face ring is discontinuous or end R is discontinuous, namely

In formula, represent f _ithe set of transition face ring, f _jrepresent f _ia certain transition face.

Rule 4: the transition face ring of certain basal plane association in transition face parameter inconsistent, then this transition face ring parameter is inconsistent, namely

$\left\{\begin{array}{c}{r}_{\mathrm{fi}}\&NotEqual;r_{\mathrm{fj}}\\ r_{\mathrm{fi}}\&Element;\{r_{f1},r_{f2},...r_{\mathrm{fn}}\}\\ r_{\mathrm{fj}}\&Element;\{r_{f1},r_{f2},...r_{\mathrm{fn}}\}\\ i\&NotEqual;j\end{array}\right.---\left(4\right)$

Wherein, F represents basal plane, i.e. the web surface of part, { r _f1, r _f2... r _fnfor basal plane F associate transition face ring in each transition face { f ₁, f ₂... f _ncorresponding to transition parameter.

Rule 5: basal plane F and the transition face ring associated by it middle transition face f _icommon edge should be straight line and arc-shaped edges, and the radius of arc-shaped edges is identical.When transition face generation local variations, transition face f _ifor multiple broken and arc-shaped edges is split into the different circular arc of multistage radius and curve, using arc radius value as the rule judging transition face local variations, this rule is also judge to cause transition face as the criterion of broken by local variations, namely

$\left\{\begin{array}{c}F\&cap;f_i=e_{\mathrm{Arci}}\\ r_{\mathrm{Arci}}\&NotEqual;r_{\mathrm{Arcj}}\\ r_{\mathrm{Arci}}\&Element;\{r_{\mathrm{Arc}1},r_{\mathrm{Arc}2},...r_{\mathrm{Arcn}}\}\\ r_{\mathrm{Arcj}}\&Element;\{r_{\mathrm{Arc}1},r_{\mathrm{Arc}2},...r_{\mathrm{Arcn}}\}\\ i\&NotEqual;j\end{array}\right.---\left(5\right)$

In formula, e _arcand e _curverepresent multi-section circular arc set and the collection of curves of composition common edge, r _arcrepresent end R arc radius, { r _arc1, r _arc2... r _arcnrepresent circular arc e _arcarc radius value corresponding to set.

Rule 6: as transition face f _iwhen the common edge being point cantact or transition face and basal plane with basal plane F is straight line, the transition face f calculated by formula (2) _irelative area be less than a certain threshold value, then transition face f _ifor broken, namely

In formula, V _vertexrepresent two sides common intersection, e _linerepresent that two sides intersection is straight line, s _firepresent f _irelative area, σ represent regulation broken scope threshold value.

Rule 7: side fillet (side R) is section, then have common edge between the fillet of side;

$\left\{\begin{array}{c}{f}_{\mathrm{ci}}\&cap;f_{\mathrm{cj}}=e\\ f_{\mathrm{ci}}\&Element;\{f_{c1},f_{c2},...f_{\mathrm{cn}}\}\\ f_{\mathrm{cj}}\&Element;\{f_{c1},f_{c2},...f_{\mathrm{cn}}\}\\ i\&NotEqual;j\end{array}\right.---\left(7\right)$

Wherein, { f _c1, f _c2... f _cnbe side fillet set, e is the common edge between the fillet of two sides.

Rule 8: the supporting surface f of transverse holes _iperpendicular to basal plane, and supporting surface is made up of plural ring, i.e. an outer shroud and multiple inner ring, if the limit number of certain inner ring is 2 and is chimb, then shows that this supporting surface comprises transverse holes, namely

$\left\{\begin{array}{c}{f}_i\&perp;F\\ {\mathrm{Count}}_{\mathrm{OutLoop}}=1\\ {\mathrm{Count}}_{\mathrm{InLoop}}\&GreaterEqual;1\\ \mathrm{InLoop}=e_{\mathrm{Convex}1}+e_{\mathrm{Convex}2}\end{array}\right.---\left(8\right)$

In formula, OutLoop represents supporting surface outer shroud, and InLoop represents supporting surface inner ring, e _convexthe side attribute of expression InLoop is chimb.

Rule 9: seam and Remained mass decision rule: seam and Remained mass cross the micro-structure cutting or owe to cut generation in modeling process, so the face forming this micro-structure is broken and is concave edge face, that is:

Rule 1+ rule 2:=seam or Remained mass (9)

Based on the transition face parameter extraction of colour code.First traversal history operation tree obtains all blending operations, to each blending operation:

Step 1 extracts the parameter (radius value etc.) that this blending operation comprises, recording parameters;

Step 2, by the transition face dyeing corresponding to this blending operation, records dye number (dye number of each blending operation is all different);

Step 3 by comprise blending operation name, parameter, dye number data structure stored in chain Table A.

Then the transition face in model is obtained, for each transition face:

Step 4 obtains the color value of this transition face;

Element in step 5 ergodic chain Table A, it is right to be carried out by the dye number of element in the color value of transition face and chained list, if to upper, then the parameter in this element is the parameter of this transition face, extracts parameter value.

Rule matching algorithm:

Input: aircraft structure three-dimensional CAD model, reference vector;

Export: dissimilar model defect;

Plane in step 1 extraction model and transition face, respectively stored in plane chained list, transition face chained list;

Step 2 travels through plane chained list, each plane is analyzed, and whether press in the decision principle judgment models of seam and Remained mass containing seam and (or) Remained mass, if have, then be deposited in the chained list of seam Remained mass data structure, and the face mark of regular 1 Sum fanction 2 will be met simultaneously in plane chained list;

Step 3 travels through plane chained list, is not having to find out basal plane in identified plane, is carried out from low to high sorting by basal plane and stored in basal plane chained list, identify processed face mark in plane chained list simultaneously according to reference vector direction;

Step 4 travels through basal plane chained list, for each basal plane, transition face ring or the expansion transition face ring of associated is found out in transition face chained list, form a basal plane ring, and stored in comprising in the chained list of basal plane and transition face data structure, claim this chained list to be basal plane loop chain table, in transition face chained list, identify processed transition face simultaneously;

Step 5 travels through basal plane loop chain table, for each element in chained list, analyze the basal plane ring in this element, and judge one by one according to the decision principle of transition face defect, by defective basal plane ring stored in comprising in the chained list of the data structures such as basal plane, transition face, type of error, this chained list is claimed to be defect basal plane loop chain table;

Step 6 travels through plane chained list, whether contains transverse holes, if having, be then deposited in the chained list of transverse holes data structure by the decision principle judgment models of transverse holes.

Claims (1)

1. an aircraft structure model defect automatic testing method, is characterized in that comprising the following steps:

The mechanism that step one, logarithmic mode defect produce and its carry out analyzing, concluding and extract corresponding decision rule in the characteristic of geometrical layers and topological layer, and be applied to the identification of defect; For new digital-to-analogue defect, whether belong to existing defect type according to its feature structurally, if do not belong to, then need to formulate its corresponding decision rule;

Step 2, for Structural Part Model to be detected, extract its face, the geometric parameter of limit and point three levels and topological attribute; For face: the concavity and convexity comprising the type in face, the area in face, the directivity in face and face; For limit: the belongingness comprising the type on limit, the length on limit, concavity and convexity and limit; For point: the belongingness comprising concavity and convexity a little and point;

Step 3, the property parameters extracted in digital-to-analogue to be detected to be mated with determining defects rule, if match, then show to there is such defect in digital-to-analogue;

Definition transition planar defect type: leak rounding, end R is discontinuous, transition parameter is inconsistent, variation, broken and side R be section; The decision method of all kinds of defect is the combination of each rule above-mentioned, and even model partial structurtes meet above-mentioned one or more rule, are namely considered as defect; There are two kinds of situations in the decision rule of defect as discontinuous in end R: even partial structurtes meet the judgement of rule 3, to be then considered as end R discontinuous for this structure; If partial structurtes meet the judgement of regular 3 Sum fanction 4 simultaneously, then this structure end R of being considered as parameter inconsistent is discontinuous;

Rule 1: if the plane f calculated _irelative area be less than a certain threshold value, then plane f _ifor broken plane, namely

$s_{\mathrm{pi}}=\frac{s_i}{\underset{s_k\&Subset;\mathrm{\&Omega;}}{\mathrm{\&Sigma;}}{s}_k+s_i}<\mathrm{\&delta;}---\left(1\right)$

In formula, s _pirepresent plane f _irelative area, δ represents the threshold value of regulation, s _ifor plane f a certain in model _iarea, Ω represents the set in this plane all of its neighbor face;

Rule 2: plane f _ithe common edge being adjacent face is concave edge, then plane f _ifor concave edge face, namely

$\left\{\begin{array}{c}{f}_i\&cap;f_p=e_{\mathrm{concave}}\\ f_p\&Element;\mathrm{\&Omega;}\end{array}\right.---\left(2\right)$

In formula, f _prepresent plane f _iadjacent surface, e _concavethe intersection on expression two sides is concave edge;

Rule 3: certain transition plane f in transition face ring _ithe common edge of the transition face be adjacent is concave edge, then this transition face ring is discontinuous or end R is discontinuous, namely

In formula, represent plane f _ithe set of transition face ring, f _jrepresent plane f _ia certain transition face;

Rule 4: the transition face ring of certain basal plane association in transition face parameter inconsistent, then this transition face ring parameter is inconsistent, namely

$\left\{\begin{array}{c}{r}_{\mathrm{fi}}\&NotEqual;r_{\mathrm{fj}}\\ r_{\mathrm{fi}}\&Element;\{r_{f1},r_{f2},\&CenterDot;\&CenterDot;\&CenterDot;r_{\mathrm{fn}}\}\\ r_{\mathrm{fj}}\&Element;\{r_{f1},r_{f2},\&CenterDot;\&CenterDot;\&CenterDot;r_{\mathrm{fn}}\}\\ i\&NotEqual;j\end{array}\right.---\left(4\right)$

Wherein, F represents basal plane, i.e. the web surface of part, { r _f1, r _f2... r _fnfor basal plane F associate transition face ring in each transition face { f ₁, f ₂... f _ncorresponding to transition parameter;

Rule 5: basal plane F and the transition face ring associated by it middle transition face f _icommon edge should be straight line and arc-shaped edges, and the radius of arc-shaped edges is identical; When transition face generation local variations, transition face f _ifor multiple broken and arc-shaped edges is split into the different circular arc of multistage radius and curve, using arc radius value as the rule judging transition face local variations, this rule is also judge to cause transition face as the criterion of broken by local variations, namely

$\left\{\begin{array}{c}F\&cap;f_i=e_{\mathrm{Arci}}\\ r_{\mathrm{Arci}}\&NotEqual;r_{\mathrm{Arcj}}\\ r_{\mathrm{Arci}}\&Element;\{r_{\mathrm{Arc}1},r_{\mathrm{Arc}2},\&CenterDot;\&CenterDot;\&CenterDot;r_{\mathrm{Arcn}}\}\\ r_{\mathrm{Arcj}}\&Element;\{r_{\mathrm{Arc}1},r_{\mathrm{Arc}2},\&CenterDot;\&CenterDot;\&CenterDot;r_{\mathrm{Arcn}}\}\\ i\&NotEqual;j\end{array}\right.---\left(5\right)$

In formula, e _arcand e _curverepresent multi-section circular arc set and the collection of curves of composition common edge, r _arcrepresent end R arc radius, { r _arc1, r _arc2... r _arcnrepresent circular arc e _arcarc radius value corresponding to set;

Rule 6: as transition face f _iwhen the common edge being point cantact or transition face and basal plane with basal plane F is straight line, the transition face f calculated by formula (2) _irelative area be less than a certain threshold value, then transition face f _ifor broken, namely

In formula, V _vertexrepresent two sides common intersection, e _linerepresent that two sides intersection is straight line, s _firepresent f _irelative area, σ represent regulation broken scope threshold value;

Rule 7: side fillet is section, then have common edge between the fillet of side;

$\left\{\begin{array}{c}{f}_{\mathrm{ci}}\&cap;f_{\mathrm{cj}}=e\\ f_{\mathrm{ci}}\&Element;\{f_{c1},f_{c2},\&CenterDot;\&CenterDot;\&CenterDot;f_{\mathrm{cn}}\}\\ f_{\mathrm{cj}}\&Element;\{f_{c1},f_{c2},f_{\mathrm{cn}}\}\\ i\&NotEqual;j\end{array}\right.---\left(7\right)$

Wherein, { f _c1, f _c2... f _cnbe side fillet set, e is the common edge between the fillet of two sides;

Rule 8: the supporting surface f of transverse holes _iperpendicular to basal plane, and supporting surface is made up of plural ring, i.e. an outer shroud and multiple inner ring, if the limit number of certain inner ring is 2 and is chimb, then shows that this supporting surface comprises transverse holes, namely

$\left\{\begin{array}{c}{f}_i\&perp;F\\ {\mathrm{Count}}_{\mathrm{OutLoop}}=1\\ {\mathrm{Count}}_{\mathrm{InLoop}}\&GreaterEqual;1\\ \mathrm{InLoop}=e_{\mathrm{Convex}1}+e_{\mathrm{Convex}2}\end{array}\right.---\left(8\right)$

In formula, OutLoop represents supporting surface outer shroud, and InLoop represents supporting surface inner ring, e _convexthe side attribute of expression InLoop is chimb;

Rule 9: seam and Remained mass decision rule; Seam and Remained mass cross the micro-structure cutting or owe to cut generation in modeling process, so the face forming this micro-structure is broken and is concave edge face, that is:

Rule 1+ rule 2:=seam or Remained mass (9)

Based on the transition face parameter extraction of colour code; First traversal history operation tree obtains all blending operations, to each blending operation:

Step 1, extract the parameter that this blending operation comprises, recording parameters;

Step 2, by corresponding to this blending operation transition face dyeing, record dye number;

Step 3, will the data structure of blending operation name, parameter and dye number be comprised stored in chain Table A;

Then the transition face in model is obtained, for each transition face:

Step 4, obtain the color value of this transition face;

Element in step 5, ergodic chain Table A, it is right to be carried out by the dye number of element in the color value of transition face and chained list, if to upper, then the parameter in this element is the parameter of this transition face, extracts parameter value;

Rule matching algorithm:

Input: aircraft structure three-dimensional CAD model and reference vector;

Export: dissimilar model defect;

Plane in step 1, extraction model and transition face, respectively stored in plane chained list and transition face chained list;

Step 2, traversal plane chained list, each plane is analyzed, and by the decision principle judgment models of seam and Remained mass whether containing seam with or Remained mass, if have, then be deposited in the chained list of seam Remained mass data structure, and the face mark of regular 1 Sum fanction 2 will be met simultaneously in plane chained list;

Step 3, traversal plane chained list, do not having to find out basal plane in identified plane, carried out from low to high sorting by basal plane and stored in basal plane chained list, identify processed face mark in plane chained list simultaneously according to reference vector direction;

Step 4, traversal basal plane chained list, for each basal plane, transition face ring or the expansion transition face ring of associated is found out in transition face chained list, form a basal plane ring, and stored in comprising in the chained list of basal plane and transition face data structure, claim this chained list to be basal plane loop chain table, in transition face chained list, identify processed transition face simultaneously;

Step 5, traversal basal plane loop chain table, for each element in chained list, analyze the basal plane ring in this element, and judge one by one according to the decision principle of transition face defect, by defective basal plane ring stored in comprising in the chained list of basal plane, transition face and type of error data structure, this chained list is claimed to be defect basal plane loop chain table;

Whether step 6, traversal plane chained list, contain transverse holes by the decision principle judgment models of transverse holes, if having, be then deposited in the chained list of transverse holes data structure.