A method for locating the wire hole of aviation electrical connector based on template matching

Abstract

The present invention relates to the technical field of automatic control, and discloses a method for locating the line position hole of an aviation electrical connector based on template matching, wherein a database containing template images of various types of aviation electrical connectors, line position hole position information P corresponding to the template images, and feature identification information T is established; a template image matching the aviation electrical connector to be inspected and the line position hole position information P and feature identification information T corresponding thereto are found from the database by a feature matching method, and the feature identification information T' in the current state of the aviation electrical connector to be inspected is calculated; based on the corresponding relationship between the feature identification information T and T', and the line position hole position information P corresponding to the template image matching the aviation electrical connector to be inspected, the position coordinate information P' of the line position hole in the current state of the aviation electrical connector to be inspected is calculated. The method of the present invention is simple and reliable, easy to operate, easy to implement, and easy to promote and apply.

Description

Technical Field

[0001] The invention relates to the technical field of automatic control, and in particular to a positioning method for a line hole of an aviation electrical connector based on template matching. Background Art

[0002] Electrical connectors are electromechanical components that connect electrical circuits. They are in great demand in various military aircraft and weapons, especially in aircraft. Due to the particularity of the use of electrical connectors, the stability of the performance of electrical connectors is extremely high, so the assembly of electrical connectors must be sufficiently precise.

[0003] During the production process, the electrical connector needs to be assembled with the wires, and different types of wires need to be inserted into the wire holes of the corresponding types. At present, most of the assembly work of electrical connectors in China is done manually, which is inefficient. In addition, during the manual operation, it is easy to be affected by various accidental factors, resulting in a decrease in the assembly quality of the electrical connector. Summary of the invention

[0004] In view of the current situation that electrical connector assembly is still at a low level of manual operation, with low efficiency and high waste of resources, the present invention provides a positioning method for wire holes of aviation electrical connectors based on template matching. The positioning method of the present invention can provide accurate wire hole coordinates for intelligent electrical connection assembly, so that the robotic arm can accurately insert the wires into the corresponding wire holes, thereby promoting the realization of automated assembly of the entire product.

[0005] The present invention can be achieved through the following technical solutions:

[0006] A method for locating a line hole of an aviation electrical connector based on template matching comprises the following steps:

[0007] Step 1: Establish a database including template images of various types of aviation electrical connectors, wire hole position information P corresponding to the template images, and feature identification information T;

[0008] Step 2: using a feature matching method, find out from the database a template image matching the aviation electrical connector to be inspected and the corresponding line hole position information P and feature identification information T, and calculate the feature identification information T' in the current state of the aviation electrical connector to be inspected;

[0009] Step 3: Calculate the position coordinate information P' of the line hole in the current state of the aviation electrical connector to be inspected based on the correspondence between the feature identification information T and T' and the line hole position information P corresponding to the template image matching the aviation electrical connector to be inspected.

[0010] Through the previously established database, the template images, line position hole information, and feature identification information of various models of aviation electrical connectors are saved in advance. In this way, when the line position hole of the aviation electrical connector to be inspected is identified, it is only necessary to identify the model and feature identification information of the aviation electrical connector to be inspected, and then the line position hole position identification of the aviation electrical connector to be inspected can be completed by using the matching information in the database. There is no need to identify the position of each line position hole one by one during the detection process, which saves calculation speed, improves detection effect, and is more in line with the needs of automated production.

[0011] Furthermore, a rectangular coordinate system is established with the center of the aviation electrical connector in the template image as the origin, the line hole position information P is set to a matrix composed of the position coordinates of all line holes contained in the template image in the order of corresponding numbers, and the feature identification information T is set to the angle information of the common identification of various types of aviation electrical connectors relative to the original center.

[0012] Further, the common identifier is set to the data identifier "1" or the letter identifier "a" of the line position hole.

[0013] Using the common identification as the characteristic identification can adapt to the positioning detection of more types of aviation electrical connectors, which helps to expand the scope of application. When a new type of aviation electrical connector appears, it is only necessary to save its template image, line hole position information P, and characteristic identification information T to the database. The recognition program is more compatible and easier to expand.

[0014] Furthermore, sample images of various types of aviation electrical connectors with the common identification set at a unified position are collected, the aviation electrical connectors in the sample images are cut out, and processed into template images with the same size requirements, and then the labels and contours corresponding to the various line holes in the template image are identified, and then the center coordinates of each line hole are obtained, and the coordinates and the corresponding labels are saved as a whole to form position information P. Finally, the angle information between the common identification and the original center is calculated as the feature identification information T to complete the establishment of the database.

[0015] Template images with the same size requirements, unified position settings for common logos, etc. can minimize the difficulty of data collection and subsequent detection and identification, and reduce the complexity of the entire calculation.

[0016] Furthermore, a SIFT feature matching method is used to find a template image matching the aviation electrical connector to be inspected from the database, and a rectangular coordinate system is established with the center of the aviation electrical connector in the corresponding image of the aviation electrical connector to be inspected as the origin. The angle information of the common features in the current state relative to the origin is calculated, and this is used as the feature identification T' in the current state. According to the corresponding relationship between the feature identification information T and T', and the line position hole position information P corresponding to the template image matching the aviation electrical connector to be inspected, the line position hole position information P' of the aviation electrical connector to be inspected in the current state is calculated.

[0017] Further, according to the angle difference between the angle information T and T', the rotation angle between the line position hole position information P' of the aviation electrical connector to be inspected in the current state and the line position hole position information P in the corresponding template image is calculated, thereby obtaining the line position hole position information P' of the aviation electrical connector to be inspected in the current state.

[0018] The beneficial technical effects of the present invention are:

[0019] By establishing a database, the template image, the line hole position information, and the feature identification information are matched one by one, and then the template image corresponding to the aviation electrical connector to be inspected is identified by using a matching method, and then the corresponding line hole position information and feature identification information are found. Finally, only the feature identification information in the image of the aviation electrical connector to be inspected needs to be calculated to obtain the position information of each line hole in the image of the aviation electrical connector to be inspected, thereby saving calculation time, improving recognition efficiency, avoiding the workstation from becoming the bottleneck of the entire production line, and contributing to the realization of production automation. In addition, the method of the present invention is simple and reliable, easy to operate, easy to implement, and easy to promote and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the overall flow chart of the present invention;

[0021] Figure 2 It is a schematic diagram of the process of acquiring the template image of the present invention;

[0022] Figure 3 is a schematic diagram of the common identification of the present invention;

[0023] Figure 4 It is a schematic diagram of different positions of the common identification of the present invention in the rectangular coordinate system where the template image is located;

[0024] Figure 5 It is a schematic diagram of the line hole position information P of the present invention. DETAILED DESCRIPTION

[0025] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings and preferred embodiments.

[0026] Aiming at solving the problem of electrical connector assembly which is still under manual operation, the present invention provides a method for positioning the wire position hole of an aviation electrical connector based on template matching, and uses an intelligent and automated method to assemble the electrical connector, such as Figure 1 As shown, the implementation details of the scheme are elaborated below. The steps are as follows:

[0027] Step 1: Create a database

[0028] First, it is necessary to collect samples of various types of aviation electrical connectors, extract the main image information containing the aviation electrical connectors according to the corresponding image information, and modify it to a unified image size to serve as a template image. Figure 2 As shown, the left picture is the collected electrical connector image data picture, and the right picture is the template image of the aerial point connector after the interception of the region of interest;

[0029] Secondly, through the study of the structures of various types of aviation electrical connectors, we found that the wire hole numbers of aviation electrical connectors are mostly numbers or letters. Although the number is different, they always start with the number "1" or the letter "a", such as Figure 3 As shown, we choose the number "1" or the letter "a" as a common identifier to facilitate the subsequent identification of the line holes of various types of aviation electrical connectors. In order to calculate the position coordinates of each line hole, we choose the center of the base where the line hole is located as the origin, establish a rectangular coordinate system, and when collecting the template image, as shown in the attached figure. Figure 4 As shown, the number "1" or the letter "a" is placed as close to the coordinate axis as possible, such as the positive direction of the X-axis. Then, the character recognition method is used to identify the labels corresponding to the wire holes on the aviation electrical connector. The edge of the corresponding wire hole is calculated using the feature extraction method of RANSAC clustering segmentation, and the center coordinate information of the corresponding wire hole is obtained. The coordinate information is saved together with the label as a whole position information such as 1: (x1, y1). Figure 5 As shown, and arranged in numerical or alphabetical order to form line hole position information P, finally, calculate the angle information of the shared mark relative to the original center, such as the shared mark uniformly sets the positive direction of the X-axis, calculate the angle between the positive direction of the X-axis as the starting edge and the line connecting the original center and the shared mark, and use this angle as the feature mark information T;

[0030] Next, each template image, line hole position information P and feature identification information T are saved one by one to complete the database establishment. In this way, when a new type of aviation electrical connector appears, just repeat the above process and save its corresponding template image, line hole position information P and feature identification information T to the database, making the software more extensible and more convenient to use.

[0031] Step 2: Match the image of the aviation electrical connector to be inspected with the database

[0032] First, the image of the aviation electrical connector to be inspected is processed according to the above method to make it have the same size as the template image in the database, and then the SIFT feature matching method is used to find the template image matching the aviation electrical connector to be inspected, as well as the corresponding line hole position information P and feature identification information T from the database. Then, a rectangular coordinate system is established with the center of the line hole base in the processed image of the aviation electrical connector to be inspected as the origin, and the common mark is identified and the angle information formed by the common mark and the origin line is calculated as the feature identification information T' in the current state.

[0033] Step 3: Calculate the line hole position information P' of the current state of the image of the aviation electrical connector to be inspected

[0034] Calculate the deviation angle between the feature identification information T' in the current state obtained in step 2 and the feature identification information T corresponding to the template image, so as to obtain the rotation angle of the aviation electrical connector to be inspected relative to the template image, and then obtain the rotation of the position coordinates of each line hole of the aviation electrical connector to be inspected relative to the line hole position of the template image, so as to obtain the line hole position information P' in the current state of the aviation electrical connector image to be inspected, and then send the obtained coordinate information of the line hole to the robot arm, and the system controls the robot arm to accurately insert the wire into the corresponding line hole of the electrical connector, thereby providing a basis for completing the automated wire plugging operation.

[0035] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples and that various changes or modifications may be made to these embodiments without departing from the principles and essence of the present invention. Therefore, the scope of protection of the present invention is limited by the appended claims.

Claims

1. A method for locating the line hole of an aviation electrical connector based on template matching, characterized in that The following steps are involved: Step 1: Establish a database including template images of various types of aviation electrical connectors, wire hole position information P corresponding to the template images, and feature identification information T; Step 2: using a feature matching method, find out from the database a template image matching the aviation electrical connector to be inspected and the corresponding line hole position information P and feature identification information T, and calculate the feature identification information T' in the current state of the aviation electrical connector to be inspected; Step 3: Calculate the position coordinate information P' of the line hole in the current state of the aviation electrical connector to be inspected according to the corresponding relationship between the feature identification information T and T' and the line hole position information P corresponding to the template image matching the aviation electrical connector to be inspected; A rectangular coordinate system is established with the center of the aviation electrical connector in the template image as the origin. The line hole position information P is set as a matrix composed of the position coordinates of all line holes contained in the template image in the order of corresponding numbers. The feature identification information T is set as the angle information of the common identification of various types of aviation electrical connectors relative to the origin; the common identification is set as the data identification "1" or the letter identification "a" of the line hole; The image of the aviation electrical connector to be inspected is processed so that it has the same size as the template image in the database. A rectangular coordinate system is established with the center of the midline hole base of the processed image of the aviation electrical connector to be inspected as the origin. The common mark is identified and the angle information formed by the common mark and the origin line is calculated to be used as the feature mark information T' in the current state.

2. The method for locating the wire hole of an aviation electrical connector based on template matching according to claim 1, characterized in that: Collect sample images of various types of aviation electrical connectors with the common identification set at a unified position, cut out the aviation electrical connectors in the sample images, process them into template images with the same size requirements, and then identify the labels and contours corresponding to each line hole in the template image, and then obtain the center coordinates of each line hole, save them and the corresponding labels as a whole, and form the line hole position information P. Finally, calculate the angle information between the common identification and the original center as the feature identification information T, and complete the database establishment.

3. The method for locating the wire hole of an aviation electrical connector based on template matching according to claim 1, characterized in that: The SIFT feature matching method is adopted to find a template image matching the aviation electrical connector to be inspected from the database, and a rectangular coordinate system is established with the center of the aviation electrical connector in the corresponding image of the aviation electrical connector to be inspected as the origin. The angle information of the common features in the current state relative to the origin is calculated, and this is used as the feature identification T' in the current state. According to the corresponding relationship between the feature identification information T and T', and the line position hole position information P in the template image matching the aviation electrical connector to be inspected, the line position hole position information P' of the aviation electrical connector to be inspected in the current state is calculated.

4. The method for locating the wire hole of an aviation electrical connector based on template matching according to claim 3, characterized in that: According to the angle difference between the angle information T and T', the rotation angle between the line position hole position information P' of the aviation electrical connector to be inspected in the current state and the line position hole position information P corresponding to the corresponding template image is calculated, so as to obtain the line position hole position information P' of the aviation electrical connector to be inspected in the current state.

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