An optimization measurement method of laser sensor based on perspective projection model

2021 ◽  
pp. 127582
Author(s):  
Zhen Zhang ◽  
Jiehu Kang ◽  
Zefeng Sun ◽  
Bin Wu
Keyword(s):  
Measurement Method ◽  
Perspective Projection ◽  
Laser Sensor ◽  
Projection Model

Research on Online Measurement Method of Hole Diameter and Position

2013 ◽  
Vol 347-350 ◽  
pp. 197-200
Author(s):  
Yu Gong ◽  
Jing Cai Zhang ◽  
Hong Qi Liu
Keyword(s):  
Comparative Analysis ◽  
Measurement System ◽  
Measurement Method ◽  
Measurement Methods ◽  
Hole Diameter ◽  
Laser Sensor ◽  
Online Measurement ◽  
Online Detection ◽  
Ccd Imaging ◽  
Inductive Sensor

In this paper, research on measurement methods of hole during the parts online detection has been made. Both diameter and position of the hole are going to be detected in the same measurement system. In order to obtain higher accuracy and efficiency, a comparative analysis test of using the contact probes, the inductive sensor, the laser sensor, the forward and back lighting CCD imaging have been achieved. Results show that the contact measurement using inductive sensor is more suitable for the system, for the reason that it has higher reliability and efficiency.

Principle and Method for Oxidation Layer Measurement in Electrolytic In-Process Dressing (ELID) Grinding

2011 ◽  
Vol 301-303 ◽  
pp. 515-519
Author(s):  
Bao Ji Ma ◽  
Yin Xia Wang
Keyword(s):  
Oxide Layer ◽  
Measurement Method ◽  
Current Sensor ◽  
Laser Sensor ◽  
Calculation Methods ◽  
Method Evaluation ◽  
Elid Grinding ◽  
Inner Surface ◽  
Variation Characteristics ◽  
Measurement Principle

Based on the analysis of formation and variation characteristics of oxide layers in ELID grinding, a new measurement principle and method for oxide layer measurement in ELID grinding was proposed. The thickness of the oxide layer was obtained based on measurement both outside surface and inner surface of the oxide layer by laser sensor and eddy current sensor. Calculation methods for measurement of the oxide layer in different ELID grinding periods were presented. In order to verify the correctness of the measurement principle and measurement method, evaluation experiments were down. Results show that the precision of the measurement is sufficient to be applied in ELID grinding.

scholarly journals Spacecraft Pose Estimation Based on Different Camera Model

2020 ◽  
Author(s):  
Li-Dong Mo ◽  
Guan-Xin Chi ◽  
Zhen-Qing Zhao
Keyword(s):  
Pose Estimation ◽  
Optimal Solution ◽  
Estimation Algorithm ◽  
Measurement Model ◽  
Depth Information ◽  
Perspective Projection ◽  
Camera Model ◽  
Projection Model ◽  
Simulation Results ◽  
Symmetrical Points

Abstract Spacecraft pose estimation is an important technology for spacecraft to maintain or change its orientation in space. For spacecraft pose estimation, when two spacecraft are relatively far away, the depth information of the space point is less than that of measuring distance, so that the camera model can be seen as a weak perspective projection model. In this paper, a spacecraft pose estimation algorithm based on four symmetrical points of the spacecraft outline is proposed. Analytical solution of spacecraft pose is obtained by solving the weak perspective projection model, which can meet the requirements of the measurement model when there is a long measurement distance. Optimal solution is obtained from the weak perspective projection model to the perspective projection model, which can meet the measurement requirement when the measuring distance is close. The simulation results show that the proposed algorithm can get better results even though the noise is large.

An Approach to Automatic Great-Scene 3D Reconstruction Based on UAV Sequence Images

2012 ◽  
Vol 229-231 ◽  
pp. 2294-2297
Author(s):  
Zi Ming Xiong ◽  
Gang Wan
Keyword(s):  
3D Reconstruction ◽  
Feature Vector ◽  
Image Sequences ◽  
Bundle Adjustment ◽  
Image Feature ◽  
Perspective Projection ◽  
Projection Model ◽  
New Thinking ◽  
Optimal Triangulation ◽  
3D Scene

In this paper, we propose an approach to automatic great-scene 3D reconstruction based on UAV sequence images. In this method, Harris feature point and SIFT feature vector is used to distill image feature, achieving images match; quasi-perspective projection model and factorization is employed to calibrate the uncalibrated image sequences automatically; Efficient suboptimal solutions to the optimal triangulation is plied to obtain the coordinate of 3D points; quasi-dense diffusing algorithm is bestowed to make 3D point denseness; the algorithm of bundle adjustment is taken to improve the precision of 3D points; the approach of Possion surface reconstruction is used to make 3D points gridded. This paper introduces the theory and technology of computer vision into great-scene 3D reconstruction, provides a new way for the construction of 3D scene, and provides a new thinking for the appliance of UAV sequence images.

scholarly journals A Planar-Dimensions Machine Vision Measurement Method Based on Lens Distortion Correction

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Qiucheng Sun ◽  
Yueqian Hou ◽  
Qingchang Tan ◽  
Guannan Li
Keyword(s):  
Measurement Method ◽  
Imaging System ◽  
Distortion Correction ◽  
Geometric Distortion ◽  
Lens Distortion ◽  
Feature Points ◽  
Projection Model ◽  
Vision Measurement ◽  
Uniform Model ◽  
Optical Imaging System

Lens distortion practically presents in a real optical imaging system causing nonuniform geometric distortion in the images and gives rise to additional errors in the vision measurement. In this paper, a planar-dimensions vision measurement method is proposed by improving camera calibration, in which the lens distortion is corrected on the pixel plane of image. The method can be divided into three steps: firstly, the feature points, only in the small central region of the image, are used to get a more accurate perspective projection model; secondly, rather than defining a uniform model, the smoothing spline function is used to describe the lens distortion in the measurement region of image, and two correction functions can be obtained by fitting two deviation surfaces; finally, a measurement method for planar dimensions is proposed, in which accurate magnification factor of imaging system can be obtained by using the correction functions. The effectiveness of the method is demonstrated by applying the proposed method to the test of measuring shaft diameter. Experimental data prove that the accurate planar-dimensions measurements can be performed using the proposed method even if images are deformed by lens distortion.

scholarly journals Perspective projection model for prism-based stereovision

2015 ◽  
Vol 23 (21) ◽  
pp. 27542 ◽  
Author(s):  
Xiaoyu Cui ◽  
Yue Zhao ◽  
Kahbin Lim ◽  
Teresa Wu
Keyword(s):  
Perspective Projection ◽  
Projection Model

A Method of Features Extraction Based on Fisheye Image

2014 ◽  
Vol 668-669 ◽  
pp. 1029-1032
Author(s):  
Bao Feng Zhang ◽  
Ying Kui Jiao ◽  
Zhi Jun Ma ◽  
Yong Chen Li ◽  
Jun Chao Zhu
Keyword(s):  
Feature Extraction ◽  
Correlation Function ◽  
Gaussian Function ◽  
Image Plane ◽  
Perspective Projection ◽  
Feature Points ◽  
Projection Model ◽  
Speeded Up Robust Features ◽  
Extraction Algorithm ◽  
Spherical Gaussian Function

In this paper, feature extraction algorithm based on spherical perspective projection model for the matching fisheye image is proposed. The fisheye image is mapped to the image plane through spherical mapping. Then the diffusion equation is formed by convolution of the image projection and spherical Gaussian function. The feature points of image are extracted based on the SIFT at the scale of spherical correlation function. Compared with SURF(Speeded Up Robust Features), more feature points in a shorter time are obtained.

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