CN111504191A - Aviation part automatic rapid measurement method based on three-dimensional laser scanning - Google Patents
Aviation part automatic rapid measurement method based on three-dimensional laser scanning Download PDFInfo
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- CN111504191A CN111504191A CN202010375968.8A CN202010375968A CN111504191A CN 111504191 A CN111504191 A CN 111504191A CN 202010375968 A CN202010375968 A CN 202010375968A CN 111504191 A CN111504191 A CN 111504191A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
- G01C21/00—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00
- G01C21/20—Instruments for performing navigational calculations
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Abstract
The invention discloses an automatic rapid measurement method of an aviation part based on three-dimensional laser scanning, which specifically comprises the following steps: s1, scanning path planning: aiming at a single part to be measured, scanning path planning is carried out, and the automatic acquisition of the measured data of the part is realized; s2, model conversion: performing model conversion on the measured data of the single part obtained in the step S1, and aligning the measured data with a theoretical digital-analog; s3, extracting and processing the feature of the part: and extracting the feature of the part, calculating the corresponding index of the part, and comparing the indexes to realize the quality analysis and key index evaluation of the part. The invention solves the problem that the quality of the part cannot be automatically, accurately and quickly analyzed in the prior art, thereby realizing the digital index evaluation.
Description
Technical Field
The invention relates to the technical field of measurement of aircraft aviation parts, in particular to an automatic rapid measurement method of an aviation part based on three-dimensional laser scanning.
Background
With the development of the aviation industry, the precision requirement of airplane products is higher and higher. Measurement technology based on three-dimensional laser scanning has been widely applied to the aviation industry and occupies an extremely important position. The existing measuring method based on three-dimensional laser scanning is mostly finished manually, the manual scanning speed is inconsistent, the time consumption is high, the scanning defect cannot be found in real time, the measuring efficiency is low, the scanned point cloud precision of parts is low, and further the measuring result is influenced. The research on the three-dimensional laser scanning-based aviation part automatic rapid measurement method has great significance in shortening the life cycle of products, improving the manufacturing precision and reducing the manufacturing cost.
Three-dimensional laser scanning technology has found widespread application in the aerospace industry: repairing the impeller by using a laser technology and reverse engineering; detecting typical characteristics of the part based on three-dimensional laser scanning and the like. Meanwhile, scan path planning is also studied by researchers at home and abroad in a large quantity. The invention provides an aviation part automatic rapid measurement method based on three-dimensional laser scanning based on a three-dimensional laser scanning technology and a scanning path planning method, and solves the problem that the quality of parts cannot be automatically, accurately and rapidly analyzed in the prior art, so that digital index evaluation is realized.
Disclosure of Invention
The invention aims to solve the technical problem of providing an automatic rapid measurement method for aviation parts based on three-dimensional laser scanning to solve the problem that the quality of the parts cannot be automatically, accurately and rapidly analyzed in the prior art.
In order to solve the technical problems, the technical scheme of the invention is as follows: the automatic rapid measurement method for the aviation parts based on three-dimensional laser scanning is provided, and has the innovation points that the method specifically comprises the following steps:
s1, scanning path planning: aiming at a single part to be measured, scanning path planning is carried out, and the automatic acquisition of the measured data of the part is realized;
s2, model conversion: performing model conversion on the measured data of the single part obtained in the step S1, and aligning the measured data with a theoretical digital-analog;
s3, extracting and processing the feature of the part: and extracting the feature of the actually measured data of the part, calculating the corresponding index of the part, and comparing the characteristic indexes of the digital model to realize the quality analysis and key index evaluation of the part.
Further, in step S1, the scan path planning for a single part to be measured specifically includes the following steps:
(1) for a single part, acquiring a part point cloud digital model;
(2) fitting various characteristics of the part based on the part digital model;
(3) and designing a scanning path optimization equation to realize scanning path planning.
Further, the step of fitting various features of the part in the step (2) specifically includes:
A. aiming at each point on the digital-analog point cloud, constructing a covariance matrix of a neighborhood point set of the point cloud, and performing SVD (singular value decomposition) so as to solve a normal vector of the point;
B. and performing various feature fitting on the digital analogy based on a Hough detection method, wherein the feature fitting comprises a principal vector and a principal axis.
Further, the process of planning the scan path in step (3) includes the following steps:
A. selecting the feature with the largest surface dimension of the part as an initial position;
B. partitioning the parts based on the characteristics, setting different scanning parameters according to different part partitions by using a line cutting method in each partition, and generating a continuous scanning path;
C. discretizing the continuous scanning path to obtain a plurality of discrete point coordinates;
D. generating 6D path points by using discrete 3D points in combination with point cloud normal vector information;
E. determining the connection sequence of the 6D path points, planning a path, performing collision detection, and completing scanning path planning;
F. and scanning based on the planned scanning path to finish the automatic acquisition of data.
Further, the method for converting the model in the step S2 includes the following steps:
(1) based on the measured data, preprocessing point cloud data, wherein the preprocessing comprises filtering, normal vector calculation and denoising;
(2) extracting key points based on the measured data, describing the characteristics of the key points, and then performing random matching with the digital analogy in the step S1 to realize coarse registration;
(3) and (3) realizing the precise registration of the measured data and the theoretical digital analogy by utilizing an ICP (inductively coupled plasma) algorithm, and finishing the registration.
Further, the step (2) specifically comprises the following steps:
A. dividing grids, sampling data based on iterative farthest distance sampling, and extracting key points;
B. performing feature description on key points based on SIFT3D feature descriptors aiming at actually measured data and digital-analog point cloud;
C. and matching the features of the actually measured data and the digital-analog point cloud at random, and selecting the matching result with the highest matching number as a coarse registration result.
Further, the method for extracting the feature and quality analysis of the part in the step S3 includes the following steps:
(1) fitting various characteristics of the measured data, such as a main normal vector of a plane or a main shaft of a cylinder;
(2) calculating corresponding indexes of the characteristics based on the fitting characteristics of the measured data;
(3) after model conversion, the mapping relation exists between the actually measured data characteristic position and the digital-analog point cloud characteristic, the digital-analog point cloud characteristic is obtained through calculation in step S1, and the digital-analog point characteristic and the actually measured data characteristic of the part are compared and analyzed, so that the quality of the aviation part is evaluated.
Compared with the prior art, the invention has the following beneficial effects:
(1) the aviation part automatic rapid measurement method based on three-dimensional laser scanning realizes automatic rapid detection of aviation parts and is high in efficiency.
(2) The invention solves the problem that the quality of the part cannot be automatically, accurately and quickly analyzed in the prior art, thereby realizing the digital index evaluation.
(3) The invention partitions the parts based on the characteristics, realizes the controllability of scanning parameters and improves the efficiency and the precision.
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The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. Embodiments of various aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a flow chart of an automatic rapid measurement method for an aviation part based on three-dimensional laser scanning.
Fig. 2 is a path diagram of a scan path planning according to the present invention.
FIG. 3 is a schematic diagram of the conversion result between the measured data and the theoretical model.
Detailed Description
In order to better understand the technical content of the present invention, specific embodiments are described below with reference to the accompanying drawings.
In the preferred embodiment of the invention, a three-dimensional laser scanning-based aviation part automatic rapid measurement method is provided, and specifically, an optional flow chart of the method is given in fig. 1. As shown in fig. 1, the measurement method includes the following operation steps:
aiming at a single part to be measured, point cloud processing is carried out on a theoretical digital model, a three-dimensional laser scanning path is planned, and scanning equipment automatically acquires measured data; based on the measured data, aligning with a theoretical digital-analog to realize application model conversion; furthermore, the part features are extracted, processed and analyzed, corresponding indexes of measured data are calculated, the indexes are compared with a digital-analog model, an index evaluation report is generated, and automatic and rapid measurement of the aviation parts is achieved.
The invention provides an automatic rapid measurement method of an aviation part based on three-dimensional laser scanning, a flow chart of which is shown in figure 1, and the method specifically comprises the following steps:
s1, scanning path planning: aiming at a single part to be measured, scanning path planning is carried out, and the automatic acquisition of the measured data of the part is realized; the method comprises the following specific steps:
(1) for a single part, acquiring a part point cloud digital model;
(2) based on a part digital model, fitting various characteristics of the part, and specifically comprising the following steps:
A. aiming at each point on the digital-analog point cloud, constructing a covariance matrix of a neighborhood point set of the point cloud, and performing SVD (singular value decomposition) so as to solve a normal vector of the point;
B. and performing various feature fitting on the digital analogy based on a Hough detection method, wherein the feature fitting comprises a principal vector and a principal axis.
(3) Designing a scanning path optimization equation to realize scanning path planning, and specifically comprising the following steps:
A. selecting the feature with the largest surface dimension of the part as an initial position;
B. partitioning the parts based on the characteristics, setting different scanning parameters according to different part partitions by using a line cutting method in each partition, and generating a continuous scanning path;
C. discretizing the continuous scanning path to obtain a plurality of discrete point coordinates;
D. generating 6D path points by using discrete 3D points in combination with point cloud normal vector information;
E. determining the connection sequence of the 6D path points, planning a path, performing collision detection, and completing scanning path planning;
F. and scanning based on the planned scanning path to complete automatic acquisition of data, wherein the path scanning result is shown in fig. 2.
S2, model conversion: performing model conversion on the measured data of the single part obtained in the step S1, and aligning the measured data with a theoretical digital-analog; the specific steps of model conversion are as follows:
(1) based on the measured data, preprocessing point cloud data, wherein the preprocessing comprises filtering, normal vector calculation and denoising;
(2) extracting key points based on the measured data, describing the characteristics of the key points, and then performing random matching with the digital analogy in the step S1 to realize coarse registration; the method comprises the following specific steps:
A. dividing grids, sampling data based on iterative farthest distance sampling, and extracting key points;
B. performing feature description on key points based on SIFT3D feature descriptors aiming at actually measured data and digital-analog point cloud;
C. and matching the features of the actually measured data and the digital-analog point cloud at random, and selecting the matching result with the highest matching number as a coarse registration result.
(3) And (3) realizing the precise registration of the measured data and the theoretical digital-analog by utilizing an ICP (inductively coupled plasma) algorithm, and finishing the registration, wherein the model conversion result is shown in figure 3.
S3, extracting and processing the feature of the part: and extracting the characteristics of the measured data of the part, calculating the corresponding indexes of the part, and comparing the characteristic indexes of the digital model to realize the quality analysis and key index evaluation of the part.
(1) Fitting various characteristics of the part, such as a main normal vector (plane) or a main axis (cylinder);
(2) calculating corresponding indexes of the characteristics based on the fitting characteristics of the measured data;
(3) after model conversion, the mapping relation exists between the actually measured data characteristic position and the digital-analog point cloud characteristic, the digital-analog point cloud characteristic is obtained through calculation in step S1, and the digital-analog point characteristic and the actually measured data characteristic of the part are compared and analyzed, so that the quality of the aviation part is evaluated.
In this disclosure, aspects of the present invention are described with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. Embodiments of the present disclosure are not necessarily defined to include all aspects of the invention. It should be appreciated that the various concepts and embodiments described above, as well as those described in greater detail below, may be implemented in any of numerous ways, as the disclosed concepts and embodiments are not limited to any one implementation. In addition, some aspects of the present disclosure may be used alone, or in any suitable combination with other aspects of the present disclosure.
Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the appended claims.
Claims (7)
1. An automatic rapid measurement method for aviation parts based on three-dimensional laser scanning is characterized by comprising the following steps:
s1, scanning path planning: aiming at a single part to be measured, scanning path planning is carried out, and the automatic acquisition of the measured data of the part is realized;
s2, model conversion: performing model conversion on the measured data of the single part obtained in the step S1, and aligning the measured data with a theoretical digital-analog;
s3, extracting and processing the feature of the part: and extracting the characteristics of the measured data of the part, calculating the corresponding characteristic indexes of the part, and comparing the digital-analog characteristics to realize the quality analysis and key index evaluation of the part.
2. The automatic rapid measurement method for the aviation parts based on the three-dimensional laser scanning as claimed in claim 1, characterized in that: in step S1, the scan path planning for a single part to be measured specifically includes the following steps:
(1) for a single part, acquiring a part point cloud digital model;
(2) fitting various characteristics of the part based on the part digital model;
(3) and designing a scanning path optimization equation to realize scanning path planning.
3. The automatic rapid measurement method for the aviation parts based on the three-dimensional laser scanning as claimed in claim 2, characterized in that: the step of fitting various characteristics of the part in the step (2) specifically comprises the following steps:
A. aiming at each point on the digital-analog point cloud, constructing a covariance matrix of a neighborhood point set of the point cloud, and performing SVD (singular value decomposition) so as to solve a normal vector of the point;
B. and performing various feature fitting on the digital analogy based on a Hough detection method, wherein the feature fitting comprises a principal vector and a principal axis.
4. The automatic rapid measurement method for the aviation parts based on the three-dimensional laser scanning as claimed in claim 2, characterized in that: the process of planning the scanning path in the step (3) comprises the following steps:
A. selecting the feature with the largest surface dimension of the part as an initial position;
B. partitioning the parts based on the characteristics, setting different scanning parameters according to different part partitions by using a line cutting method in each partition, and generating a continuous scanning path;
C. discretizing the continuous scanning path to obtain a plurality of discrete point coordinates;
D. generating 6D path points by using discrete 3D points in combination with point cloud normal vector information;
E. determining the connection sequence of the 6D path points, planning a path, performing collision detection, and completing scanning path planning;
F. and scanning based on the planned scanning path to finish the automatic acquisition of data.
5. The automatic rapid measurement method for the aviation parts based on the three-dimensional laser scanning as claimed in claim 1, characterized in that: the method for converting the model in the step S2 includes the steps of:
(1) based on the measured data, preprocessing point cloud data, wherein the preprocessing comprises filtering, normal vector calculation and denoising;
(2) extracting key points based on the measured data, describing the characteristics of the key points, and then performing random matching with the digital analogy in the step S1 to realize coarse registration;
(3) and (3) realizing the precise registration of the measured data and the theoretical digital analogy by utilizing an ICP (inductively coupled plasma) algorithm, and finishing the registration.
6. The method for automatically and rapidly measuring the aviation parts based on the three-dimensional laser scanning as claimed in claim 5, wherein the step (2) specifically comprises the following steps:
A. dividing grids, sampling data based on iterative farthest distance sampling, and extracting key points;
B. performing feature description on key points based on SIFT3D feature descriptors aiming at actually measured data and digital-analog point cloud;
C. and matching the features of the actually measured data and the digital-analog point cloud at random, and selecting the matching result with the highest matching number as a coarse registration result.
7. The automatic rapid measurement method for the aviation parts based on the three-dimensional laser scanning as claimed in claim 1, characterized in that: the method for extracting the part features and analyzing the quality in the step S3 comprises the following steps:
(1) fitting various characteristics of the measured data, such as a main normal vector of a plane or a main shaft of a cylinder;
(2) calculating corresponding indexes of the characteristics based on the fitting characteristics of the measured data;
(3) after model conversion, the mapping relation exists between the actually measured data characteristic position and the digital-analog point cloud characteristic, the digital-analog point cloud characteristic is obtained through calculation in step S1, and the digital-analog point characteristic and the actually measured data characteristic of the part are compared and analyzed, so that the quality of the aviation part is evaluated.
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| CN112161566A (en) * | 2020-09-27 | 2021-01-01 | 西安电子科技大学 | Intelligent part manufacturing quality detection method based on model |
| CN112229356A (en) * | 2020-08-28 | 2021-01-15 | 成都飞机工业（集团）有限责任公司 | Part quality detection method based on point measurement data |
| CN112817308A (en) * | 2020-12-30 | 2021-05-18 | 北京航空航天大学 | On-line measurement collision-free global path planning method and system |
| CN114295048A (en) * | 2021-12-21 | 2022-04-08 | 北京紫微宇通科技有限公司 | Spacecraft structure digital detection method based on laser scanner |
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