Nothing Special   »   [go: up one dir, main page]

CN112950545B - A method for detecting bending of bar steel - Google Patents

A method for detecting bending of bar steel Download PDF

Info

Publication number
CN112950545B
CN112950545B CN202110146384.8A CN202110146384A CN112950545B CN 112950545 B CN112950545 B CN 112950545B CN 202110146384 A CN202110146384 A CN 202110146384A CN 112950545 B CN112950545 B CN 112950545B
Authority
CN
China
Prior art keywords
pixel
steel
features
image
bending
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110146384.8A
Other languages
Chinese (zh)
Other versions
CN112950545A (en
Inventor
李桂东
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nanjing Yuntong Technology Co ltd
Suzhou Yuntong Technology Co ltd
Original Assignee
Suzhou Yuntong Technology Co ltd
Nanjing Yuntong Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Suzhou Yuntong Technology Co ltd, Nanjing Yuntong Technology Co ltd filed Critical Suzhou Yuntong Technology Co ltd
Priority to CN202110146384.8A priority Critical patent/CN112950545B/en
Publication of CN112950545A publication Critical patent/CN112950545A/en
Application granted granted Critical
Publication of CN112950545B publication Critical patent/CN112950545B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00Image analysis
    • G06T7/0002Inspection of images, e.g. flaw detection
    • G06T7/0004Industrial image inspection
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06NCOMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS
    • G06N3/00Computing arrangements based on biological models
    • G06N3/02Neural networks
    • G06N3/04Architecture, e.g. interconnection topology
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06NCOMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS
    • G06N3/00Computing arrangements based on biological models
    • G06N3/02Neural networks
    • G06N3/08Learning methods
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00Image analysis
    • G06T7/10Segmentation; Edge detection
    • G06T7/11Region-based segmentation
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00Image analysis
    • G06T7/10Segmentation; Edge detection
    • G06T7/13Edge detection
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06VIMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V10/00Arrangements for image or video recognition or understanding
    • G06V10/40Extraction of image or video features
    • G06V10/44Local feature extraction by analysis of parts of the pattern, e.g. by detecting edges, contours, loops, corners, strokes or intersections; Connectivity analysis, e.g. of connected components
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00Indexing scheme for image analysis or image enhancement
    • G06T2207/20Special algorithmic details
    • G06T2207/20081Training; Learning

Landscapes

  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Biomedical Technology (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Artificial Intelligence (AREA)
  • Software Systems (AREA)
  • Biophysics (AREA)
  • Computational Linguistics (AREA)
  • Data Mining & Analysis (AREA)
  • Evolutionary Computation (AREA)
  • General Health & Medical Sciences (AREA)
  • Molecular Biology (AREA)
  • Computing Systems (AREA)
  • Mathematical Physics (AREA)
  • Quality & Reliability (AREA)
  • Multimedia (AREA)
  • Image Analysis (AREA)

Abstract

本发明公开了一种棒材钢料弯曲检测方法,该方法用耐高温摄像机实时拍摄传送带上将送入加热炉的棒材,然后用基于深度学习的分割网络实时分割出钢料的图像,然后对分割出的钢料图像通过边缘检测算法检测钢料的边界特征,从中提取出三条侧棱特征,通过侧棱特征判断钢料是否弯曲,阻止弯曲的钢料送入加热炉中,实现了棒材钢料弯曲自动化检测,避免弯曲钢料进入加热炉导致卡钢的问题。

The present invention discloses a method for detecting the bending of bar steel materials. The method uses a high-temperature resistant camera to shoot the bars to be sent into a heating furnace on a conveyor belt in real time, and then uses a segmentation network based on deep learning to segment the image of the steel materials in real time. Then, the segmented steel material image is subjected to an edge detection algorithm to detect the boundary features of the steel materials, and three side edge features are extracted therefrom. It is judged whether the steel materials are bent according to the side edge features, and the bent steel materials are prevented from being sent into the heating furnace, thereby realizing the automatic detection of the bending of bar steel materials and avoiding the problem of steel jamming caused by the bent steel materials entering the heating furnace.

Description

Bar steel bending detection method
Technical Field
The invention belongs to the technical field of computer vision and image detection, and particularly relates to a method and a device for detecting bending of bar steel.
Background
The rolled bar steel material can produce bending deformation in the processing or conveying process, the bending deformation can damage subsequent conveying equipment, when the bent steel material is conveyed into a heating furnace, steel clamping can possibly occur, because the temperature of the heating furnace is extremely high, the steel clamping is difficult to take out, time and manpower and material resources can be seriously wasted, and even equipment failure is damaged. Therefore, before the steel is conveyed to the heating furnace, bending measurement is required to be carried out on the steel, when the steel is detected to be bent beyond a certain degree, the conveyor belt is prevented from being conveyed continuously, an alarm is sent to the front end, and a monitoring person or a mechanical arm is enabled to take off the bent steel.
Disclosure of Invention
The invention aims to solve the technical problem of providing a bar steel bending detection method aiming at the defects in the prior art.
In order to achieve the technical purpose, the invention adopts the following technical scheme:
a bar steel bending detection method comprises the following steps:
Step S1, fixing a high-temperature-resistant network camera above a bar steel material obliquely, and collecting an image of the steel material on a conveyor belt in real time;
S2, inputting the acquired images into a segmentation network based on deep learning, and segmenting images of bars in the images in real time;
s3, performing edge detection on the segmented steel material image by using an edge detection algorithm to extract steel material boundary characteristics and three side edge characteristics;
s4, detecting whether the steel is bent or not based on the three side edge characteristics;
and S5, sending an alarm to the front end when the bending of the steel is detected, and preventing the bent steel from being sent into the heating furnace.
In order to optimize the technical scheme, the specific measures adopted further comprise:
further, in the step S1, the high temperature resistant network camera collects two side surfaces and three side edges of the steel material.
Further, the step S2 specifically includes:
S21, inputting image data into a segmentation network based on deep learning, and judging whether each pixel belongs to steel materials or not;
s22, selecting all pixels judged to belong to the steel material in the image to form a steel material image;
S23, calculating the distance between the two farthest pixels in the steel image, and when the distance is smaller than a certain threshold value, judging that the steel does not completely enter the shooting visual field, and detecting the next image by turning to S21.
Further, the deep learning-based segmentation network in step S21 includes the steps of:
S211, extracting each pixel characteristic of the image by using a multi-layer sensor;
s212, carrying out maximum pooling on a3 multiplied by 3 neighborhood, a5 multiplied by 5 neighborhood and a 7 multiplied by 7 neighborhood which take each pixel as a center to obtain local features of 3 scales of each pixel, and linking the three features to form a multi-scale local feature of each pixel;
s213, extracting high-dimensional features of the multi-scale local features of each pixel by using a multi-layer perceptron, and then maximally pooling the high-dimensional features of all pixels to obtain global features;
S214, extracting weight from the high-dimensional feature of each pixel, linking the multi-scale local feature and the global feature of each pixel, and multiplying the multi-scale local feature and the global feature with the weight to obtain weighted features;
S215, the weighted characteristic of each pixel is reduced to one dimension through the full connection layer, the segmentation probability of each pixel is obtained through calculation by using a sigmoid function, a cross entropy loss function is calculated for training, and whether each pixel belongs to the pixel of steel materials or not is judged.
Further, the step S3 specifically includes:
s31, extracting boundary pixels from the segmented steel material image by using an edge detection algorithm, and constructing a minimum spanning tree by using a kruskal algorithm, wherein the boundary pixels are used as nodes of the tree;
s32, calculating a pixel unit normal vector according to the nearest k neighborhood of each boundary pixel;
S33, selecting one pixel in boundary pixels, and traversing all boundary pixels to obtain all break points when the absolute value of the inner product of the unit normal vector of any pixel in the k neighborhood of the pixel and the unit normal vector of the pixel is smaller than a set threshold value;
And S34, dividing the minimum spanning tree into a plurality of subtrees by all break points, and selecting three subtrees with the most nodes as three side edge features.
Further, step S4 specifically includes:
s41, respectively carrying out straight line detection on three side edge characteristics by using a RANSAC algorithm;
step S42, calculating the distance between all pixel points in the three side edge features and corresponding straight lines, and judging that the boundary line corresponding to the pixel is bent when the pixel with the distance larger than the set threshold exists;
And S43, bending the steel material when any one of the three side edge characteristics is bent.
Further, step S5 is specifically that an alarm is sent to the front end controller when the bending of the steel is detected, the steel conveyor belt is interrupted to transmit, and after the bent steel is taken down, the conveyor belt continues to convey the steel, and the next steel is detected.
The invention has the beneficial effects that:
The invention provides a method and a device for detecting steel bar bending based on an image segmentation algorithm and an image edge detection technology of deep learning. According to the method, an image of conveying steel materials is acquired by a high-temperature-resistant camera, the steel materials are segmented by a deep learning image segmentation algorithm, and the bending degree of the steel materials is detected by extracting boundary characteristics of the steel materials by an edge detection algorithm, so that the problem of steel material bending detection before the steel materials are conveyed into a heating furnace is solved, and subsequent accidents caused by conveying the bent steel materials into the heating furnace are avoided.
Drawings
FIG. 1 is a diagram of a method and apparatus for detecting bending of steel bar stock according to the present invention;
FIG. 2 is a schematic view of a shooting position of a high-temperature-resistant camera according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a segmentation network structure based on deep learning according to an embodiment of the present invention;
FIG. 4 is a schematic view of boundary features and three side edge features of a steel material according to an embodiment of the present invention.
Detailed Description
Embodiments of the present invention are described in further detail below with reference to the accompanying drawings.
As shown in fig. 1, the invention provides a bar steel bending detection method, which comprises the following steps:
Step S1, fixing a high-temperature-resistant network camera above a bar steel material obliquely, and collecting an image of the steel material on a conveyor belt in real time;
Because the detection environment is located beside the heating furnace, the environment temperature is higher, in order not to influence the image acquisition effect, the DS-NXCN A204 CMOS star light level high-temperature-resistant air-cooled barrel type network camera is used for acquiring images, when steel materials are bent, at least one surface (two side edges) is bent, so that whether the steel materials are bent or not can be judged by detecting three steel materials from the four side edges, a camera is fixed above a conveying belt of the steel materials of the bar, the two side surfaces (three side edges) of the steel materials can be completely located in the visual field of the camera, after the images are acquired, due to limited wireless transmission speed and higher environment temperature, special high-temperature-resistant cables are required to be used for transmitting image data, and fig. 2 is a schematic diagram of the shooting position of the high-temperature-resistant camera.
S2, inputting the acquired images into a segmentation network based on deep learning, and segmenting images of bars in the images in real time;
Inputting image data into a segmentation network based on deep learning, judging whether each pixel belongs to steel materials, then selecting all pixels judged to belong to the steel materials to form a steel material image, calculating the distance between the two farthest pixels in the steel material image, judging that the steel materials do not enter a shooting visual field completely when the distance is smaller than a certain threshold value, judging that the steel material image shooting is incomplete, and continuously detecting the next image, wherein fig. 3 is a segmentation network structure schematic diagram based on the deep learning;
wherein the deep learning based segmentation network comprises the steps of:
Step (1) extracting each pixel characteristic of an image by using a multi-layer sensor;
Step (2) carrying out maximum pooling on a3×3 neighborhood, a5×5 domain and a 7×7 domain which take each pixel as a center to obtain local features of 3 scales of each pixel, and linking the three features to form a multi-scale local feature of each pixel;
extracting high-dimensional features of multi-scale local features of each pixel by using a multi-layer perceptron, and then maximally pooling the high-dimensional features of all pixels to obtain global features;
Step (4) extracting weight from the high-dimensional feature of each pixel, linking the multi-scale local feature and the global feature of each pixel, and multiplying the multi-scale local feature and the global feature with the weight to obtain weighted features;
and (5) reducing the weighted characteristic of each pixel to one dimension through a full connection layer, obtaining the segmentation probability of each pixel by using a sigmoid function, calculating a cross entropy loss function for training, and judging whether each pixel belongs to the pixel of the steel material.
S3, performing edge detection on the segmented steel material image by using an edge detection algorithm to extract steel material boundary characteristics and three side edge characteristics;
Extracting boundary pixels from the segmented steel material image by using an edge detection algorithm, constructing a minimum spanning tree by using a kruskal algorithm, taking the boundary pixels as nodes of the tree, calculating the unit normal vector of the pixel according to the nearest k neighborhood of each boundary pixel, selecting one pixel in the boundary pixels, taking the pixel as a breakpoint when the inner product absolute value of the unit normal vector of any pixel in the k neighborhood of the pixel and the unit normal vector of the pixel is smaller than a set threshold value, traversing all the boundary pixels to obtain all the breakpoints, dividing the minimum spanning tree into a plurality of subtrees by all the breakpoints, and selecting three subtrees with the most nodes as three side edge features.
S4, detecting whether the steel is bent or not based on the three side edge characteristics;
the method comprises the steps of respectively carrying out straight line detection on three side edge features by using a RANSAC algorithm, calculating the distance between all pixel points in the three side edge features and corresponding straight lines, judging that a boundary line corresponding to a pixel is bent when the pixel with the distance larger than a set threshold exists, and bending steel materials when any one of the three side edge features is bent.
And S5, sending an alarm to the front-end controller when the bending of the steel is detected, interrupting the transmission of the steel conveyor belt, and continuously conveying the steel by the conveyor belt after the bent steel is taken down, so as to detect the next steel.
The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above examples, and all technical solutions belonging to the concept of the present invention belong to the protection scope of the present invention. It should be noted that modifications and adaptations to the invention without departing from the principles thereof are intended to be within the scope of the invention as set forth in the following claims.

Claims (5)

1. The steel bar bending detection method is characterized by comprising the following steps of:
Step S1, fixing a high-temperature-resistant network camera above a bar steel material obliquely, and collecting an image of the steel material on a conveyor belt in real time;
S2, inputting the acquired images into a segmentation network based on deep learning, and segmenting images of bars in the images in real time;
s3, performing edge detection on the segmented steel material image by using an edge detection algorithm to extract steel material boundary characteristics and three side edge characteristics;
s4, detecting whether the steel is bent or not based on the three side edge characteristics;
S5, sending an alarm to the front end when the bending of the steel is detected, and preventing the bent steel from being sent into the heating furnace;
The step S3 specifically comprises the following steps:
s31, extracting boundary pixels from the segmented steel material image by using an edge detection algorithm, and constructing a minimum spanning tree by using a kruskal algorithm, wherein the boundary pixels are used as nodes of the tree;
Step S32, calculating the pixel unit normal vector according to the nearest k neighborhood of each boundary pixel;
step S33, selecting one pixel in boundary pixels, and traversing all boundary pixels to obtain all break points when the absolute value of the inner product of the unit normal vector of any pixel in the k neighborhood of the pixel and the unit normal vector of the pixel is smaller than a set threshold value;
Step S34, dividing the minimum spanning tree into a plurality of subtrees by all break points, and selecting three subtrees with the most nodes as three side edge features;
The step S4 specifically includes:
s41, respectively carrying out straight line detection on three side edge characteristics by using a RANSAC algorithm;
step S42, calculating the distance between all pixel points in the three side edge features and corresponding straight lines, and judging that the boundary line corresponding to the pixel is bent when the pixel with the distance larger than the set threshold exists;
And S43, bending the steel material when any one of the three side edge characteristics is bent.
2. The method for detecting bending of steel bar according to claim 1, wherein the high-temperature-resistant network camera in the step S1 is used for collecting two side surfaces and three side edges of the steel bar.
3. The method for detecting bending of steel bar according to claim 2, wherein the step S2 is specifically:
s21, inputting image data into a segmentation network based on deep learning, and judging whether each pixel belongs to steel materials or not;
S22, selecting all pixels judged to belong to the steel material in the image to form a steel material image;
And S23, calculating the distance between the two farthest pixels in the steel image, and when the distance is smaller than a certain threshold value, judging that the steel does not completely enter the shooting visual field, and detecting the next image by turning to S21.
4. The method for detecting bending of steel bar according to claim 3, wherein the deep learning-based segmentation network in the step S21 comprises the following steps:
Step S211, extracting each pixel characteristic of the image by using the multi-layer perceptron;
Step S212, carrying out maximum pooling on a 3 multiplied by 3 neighborhood, a 5 multiplied by 5 neighborhood and a 7 multiplied by 7 neighborhood which take each pixel as a center to obtain local features of 3 scales of each pixel, and linking the three features to form a multi-scale local feature of each pixel;
Step S213, extracting high-dimensional features from the multi-scale local features of each pixel by using a multi-layer sensor, and then maximally pooling the high-dimensional features of all pixels to obtain global features;
step S214, extracting weight from the high-dimensional feature of each pixel, linking the multi-scale local feature and the global feature of each pixel, and multiplying the multi-scale local feature and the global feature with the weight to obtain weighted features;
And S215, reducing the weighted characteristic of each pixel to one dimension through a full connection layer, calculating the segmentation probability of each pixel by using a sigmoid function, calculating a cross entropy loss function for training, and judging whether each pixel belongs to the pixel of the steel material.
5. The method for detecting bending of steel bar according to claim 4, wherein the step S5 is specifically to send an alarm to the front end controller when bending of the steel bar is detected, interrupt transmission of the steel bar conveyor belt, and continue conveying the steel bar by the conveyor belt after the bent steel bar is removed for detection of the next steel bar.
CN202110146384.8A 2021-02-03 2021-02-03 A method for detecting bending of bar steel Active CN112950545B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110146384.8A CN112950545B (en) 2021-02-03 2021-02-03 A method for detecting bending of bar steel

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110146384.8A CN112950545B (en) 2021-02-03 2021-02-03 A method for detecting bending of bar steel

Publications (2)

Publication Number Publication Date
CN112950545A CN112950545A (en) 2021-06-11
CN112950545B true CN112950545B (en) 2024-12-13

Family

ID=76241944

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110146384.8A Active CN112950545B (en) 2021-02-03 2021-02-03 A method for detecting bending of bar steel

Country Status (1)

Country Link
CN (1) CN112950545B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115496754B (en) * 2022-11-16 2023-04-11 深圳佰维存储科技股份有限公司 Curvature detection method and device of SSD, readable storage medium and electronic equipment

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102441581A (en) * 2010-09-30 2012-05-09 邓玥 Device and method for online detection of section size of profile steel based on machine vision
CN110648316A (en) * 2019-09-07 2020-01-03 创新奇智(成都)科技有限公司 Steel coil end face edge detection algorithm based on deep learning

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5233372B2 (en) * 2008-04-03 2013-07-10 新日鐵住金株式会社 Steel plate warpage detection system and method
JP5828817B2 (en) * 2012-09-03 2015-12-09 株式会社神戸製鋼所 Shape inspection method for steel bars
CN110926378A (en) * 2019-12-16 2020-03-27 太原科技大学 An improved bar straightness detection system and method based on visual inspection
CN211783345U (en) * 2020-03-16 2020-10-27 成都桐林铸造实业有限公司 Curvature detection device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102441581A (en) * 2010-09-30 2012-05-09 邓玥 Device and method for online detection of section size of profile steel based on machine vision
CN110648316A (en) * 2019-09-07 2020-01-03 创新奇智(成都)科技有限公司 Steel coil end face edge detection algorithm based on deep learning

Also Published As

Publication number Publication date
CN112950545A (en) 2021-06-11

Similar Documents

Publication Publication Date Title
CN110171691A (en) Belt conveyor belt tearing condition detection method and detection system
CN110287963B (en) OCR recognition method for comprehensive performance test
CN111369516B (en) Detection method of transformer bushing heating defects based on infrared image recognition
CN101957325A (en) Substation equipment appearance abnormality recognition method based on substation inspection robot
CN107084992A (en) A capsule detection method and system based on machine vision
CN118608504A (en) A method and system for detecting component surface quality based on machine vision
CN112950545B (en) A method for detecting bending of bar steel
CN114529839A (en) Unmanned aerial vehicle routing inspection-oriented power transmission line hardware anomaly detection method and system
CN110493574B (en) Security monitoring visualization system based on streaming media and AI technology
CN114092478A (en) Anomaly detection method
CN116309447B (en) Dam slope crack detection method based on deep learning
CN114612403A (en) A kind of intelligent detection method and system for damage defect of feeding belt
CN115049955A (en) Fire detection analysis method and device based on video analysis technology
CN118183215A (en) AI technology-based coal conveying belt abnormality detection system
CN115861210A (en) Transformer substation equipment abnormity detection method and system based on twin network
CN108615057B (en) CNN-based abnormity identification method for cable tunnel lighting equipment
CN117252840B (en) Photovoltaic array defect elimination assessment method, device and computer equipment
CN117029703B (en) Communication cable field production data real-time management monitoring system
CN109977962B (en) Method and system for automatically identifying fault hidden danger of optical cable
CN111325073A (en) Monitoring video abnormal behavior detection method based on motion information clustering
CN112907524B (en) Method for detecting fault of fire-proof plate of rail wagon based on image processing
CN116002480A (en) Automatic detection method and system for accidental fall of passengers in elevator car
CN102514771A (en) Industrial explosive roll transmission attitude identification and diagnosis system and method thereof
Wang et al. Thermal defect detection and location for power equipment based on improved VGG16
CN110930362A (en) Screw safety detection method, device and system

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
TA01 Transfer of patent application right
TA01 Transfer of patent application right

Effective date of registration: 20210903

Address after: Room 2605, no.1698, Shuanglong Avenue, Jiangning District, Nanjing City, Jiangsu Province 211106

Applicant after: Nanjing Yuntong Technology Co.,Ltd.

Applicant after: Suzhou Yuntong Technology Co.,Ltd.

Address before: Room 2605, no.1698, Shuanglong Avenue, Jiangning District, Nanjing City, Jiangsu Province 211106

Applicant before: Nanjing Yuntong Technology Co.,Ltd.

GR01 Patent grant
GR01 Patent grant