Two-dimensional high-precision non-contact automatic measurement method based on image corner coordinates

2021 ◽  
pp. 095440622098112
Author(s):  
Maoyue Li ◽  
Yonghao Xu ◽  
Zengtao Chen ◽  
Kangsheng Ma ◽  
Lifei Liu
Keyword(s):  
High Precision ◽  
Measurement Method ◽  
Low Cost ◽  
Automatic Measurement ◽  
Detection Algorithm ◽  
Contour Detection ◽  
Two Dimensional ◽  
High Precision Measurement ◽  
Standard Size ◽  
Actual Size

Aiming at some shortcomings of the existing non-contact two-dimensional high-precision measurement methods, this paper proposes a two-dimensional high-precision non-contact automatic measurement method based on the corner coordinates of the image. Firstly, this paper designs a set of simple image acquisition device and explains the advantages of the Canny operator used in the image contour detection algorithm. Subsequently, this paper proposes a dimension calibration algorithm based on image corner coordinates, which can convert the pixel size to the actual size, and achieves the function of the algorithm by hierarchical, multi-step processing of the image. Finally, in order to realize the intelligent positioning and selection of the standard size workpiece position, an automatic measurement and positioning system is designed, which can convert the actual size signal into the pulse time control signal. The experimental results show that the measurement method proposed in this paper has the advantages of fast measurement speed, high robustness, low cost and high degree of automation. When using a black-and-white checkerboard paper with an accuracy of 0.1 mm, the measurement accuracy can reach the micron level.

Research on High Precision and Non-Contact Measuring System for Geometric Parameter of the Irregular Shape

2011 ◽  
Vol 128-129 ◽  
pp. 694-697
Author(s):  
Yu Hua Cheng ◽  
Li Bing Bai ◽  
Lin Nie
Keyword(s):  
High Precision ◽  
Geometric Parameter ◽  
Large Scale ◽  
Low Cost ◽  
Automatic Measurement ◽  
Ccd Camera ◽  
Irregular Shape ◽  
Measuring System ◽  
High Precision Measurement ◽  
Low Efficiency

Traditional measurement for geometric parameter of the irregular shape is considered as high cost and low efficiency, and large-scale automatic measurement cannot be achieved. In this paper, a low-cost, high-precision measurement system of irregular shape is presented. The system based on linear array CCD non-contact measurement method, in which a CCD camera is controlled to scan the projection of thread in the parallel optical field to acquire thread images. Meanwhile, an edge detection method based on gradient operator and linear fitting principle is proposed, the results show that the design improve the measurement precision efficiently.

scholarly journals A low-cost high-precision measurement method of string motion

2014 ◽  
Vol 333 (17) ◽  
pp. 3881-3888 ◽  
Author(s):  
J.-L. Le Carrou ◽  
D. Chadefaux ◽  
L. Seydoux ◽  
B. Fabre
Keyword(s):  
High Precision ◽  
Precision Measurement ◽  
Measurement Method ◽  
Low Cost ◽  
High Precision Measurement

Design of Automatic Measurement System of Lithium Battery Electrochemical Impedance Spectroscopy Based on Microcomputer

2012 ◽  
Vol 241-244 ◽  
pp. 259-264 ◽  
Author(s):  
Wang Li ◽  
Gen Wang Liu ◽  
Fu He Yang
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
High Precision ◽  
Measurement System ◽  
Lithium Battery ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Automatic Measurement ◽  
Response Curves ◽  
High Level

A system of miniaturized lithium battery electrochemical impedance spectroscopy (EIS) measurement is designed with high precision impedance converter chip AD5933 as its core. The measurement range of the system is from 0.010Hz to 100 KHz. Meanwhile, by using a high-level programming language of C#, an interface is developed which can real-time graphic display of EIS information. Through measurement and analysis of two types of impedance, the results show that detection precision of the system is less than 3.5%. Finally, amplitude-frequency response curves and Nyquist plots of HL-18650 M lithium battery at different state of charge (SOC) levels are measured. Compared with lithium battery EIS measurement system by traditional division, this system has the outstanding advantages of small size, high level of integration, low cost, simple operation and high precision. It is helpful to the mass production and application of lithium battery EIS measurement system.

scholarly journals Parameter Measurement of Biaxial Braided Composite Preform Based on Phase Congruency

2019 ◽  
Vol 19 (1) ◽  
pp. 8-16
Author(s):  
Zhitao Xiao ◽  
Lei Pei ◽  
Fang Zhang ◽  
Ying Sun ◽  
Lei Geng ◽  
...  
Keyword(s):  
Automatic Measurement ◽  
Detection Algorithm ◽  
High Accuracy ◽  
Block Matching ◽  
Experimental Results ◽  
Corner Detection ◽  
New Method ◽  
Two Dimensional ◽  
Phase Congruency ◽  
Braided Composite

Abstract In this paper, a new method based on phase congruency is proposed to measure pitch lengths and surface braiding angles of two-dimensional biaxial braided composite preforms. Lab space transform and BM3D (block-matching and 3D filter) are used first to preprocess the original acquired images. A corner detection algorithm based on phase congruency is then proposed to detect the corners of the preprocessed images. Pitch lengths and surface braiding angles are finally measured based on the detected corner maps. Experimental results show that our method achieves the automatic measurement of pitch lengths and the surface braiding angles of biaxial braided composite preforms with high accuracy.

Error Compensation Technology of Semi-Strapdown MEMS Inertial Measurement System

2014 ◽  
Vol 609-610 ◽  
pp. 1213-1218 ◽  
Author(s):  
Jie Li ◽  
Jing De Zhu ◽  
Li Peng Hou ◽  
Jun Liu
Keyword(s):  
High Precision ◽  
Error Compensation ◽  
High Speed ◽  
Measurement Method ◽  
Motor Speed ◽  
High Precision Measurement ◽  
Inertial Measurement ◽  
Force Equation ◽  
Speed Fluctuation ◽  
Set Up

Semi-strapdown inertial measurement method provides a new solution for the high-precision measurement on flight attitude of high-spinning ammunition, while the specific set of components in the semi-strapdown application will cause a series of errors. This paper mainly analyzes the generation mechanism of motor speed fluctuation error and the misalignment error in coupling axis. Then the instantaneous motor speed measurement method based on the high-precision gyroscope is designed and the misalign model of coupling axis is set up, MEMS inertial measurement area centripetal force equation under the condition of high speed is worked out, and accuracy error parameters affecting the measurement are obtained. Finally, the paper provides corresponding error compensation method and comparative tests are conducted. The results show that the compensated system improves the accuracy of attitude angle calculating and the error has been effectively suppressed.

scholarly journals Assistive guidance system for the visually impaired

2017 ◽  
Author(s):  
Rohit Takhar ◽  
Tushar Sharma ◽  
Udit Arora ◽  
Sohit Verma
Keyword(s):  
Credit Card ◽  
Visually Impaired ◽  
Low Cost ◽  
Histogram Equalization ◽  
Detection Algorithm ◽  
Contour Detection ◽  
Guidance System ◽  
Raspberry Pi ◽  
Pixel Intensity ◽  
Detection And Recognition

In recent years, with the improvement in imaging technology, the quality of small cameras have significantly improved. Coupled with the introduction of credit-card sized single-board computers such as Raspberry Pi, it is now possible to integrate a small camera with a wearable computer. This paper aims to develop a low cost product, using a webcam and Raspberry Pi, for visually-impaired people, which can assist them in detecting and recognising pedestrian crosswalks and staircases. There are two steps involved in detection and recognition of the obstacles i.e pedestrian crosswalks and staircases. In detection algorithm, we extract Haar features from the video frames and push these features to our Haar classifier. In recognition algorithm, we first convert the RGB image to HSV and apply histogram equalization to make the pixel intensity uniform. This is followed by image segmentation and contour detection. These detected contours are passed through a pre-processor which extracts the region of interests (ROI). We applied different statistical methods on these ROI to differentiate between staircases and pedestrian crosswalks. The detection and recognition results on our datasets demonstrate the effectiveness of our system.

scholarly journals A High Precision Time Grating Displacement Sensor Based on Temporal and Spatial Modulation of Light-Field

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 921 ◽  
Author(s):  
Min Fu ◽  
Changli Li ◽  
Ge Zhu ◽  
Hailin Shi ◽  
Fan Chen
Keyword(s):  
High Precision ◽  
Light Field ◽  
Light Transmission ◽  
Low Cost ◽  
Optimization Method ◽  
Spatial Modulation ◽  
Displacement Sensor ◽  
High Precision Measurement ◽  
Object Movement ◽  
Field Modulation

A new displacement sensor with light-field modulation, named as time grating, was proposed in this study. The purpose of this study was to reduce the reliance on high-precision measurements on high-precision manufacturing. The proposed sensor uses a light source to produce an alternative light-field simultaneously for four groups of sinusoidal light transmission surfaces. Using the four orthogonally alternative light-fields as the carrier to synthesize a traveling wave signal which makes the object movement in the spatial proportion to the signal phase shift in the time, the moving displacement of the object can be measured by counting time pulses. The influence of the light-field distribution on sensor measurement error was analyzed in detail. Aimed to reduce these influences, an optimization method that used continuous cosinusoidal light transmission surfaces with spatially symmetrical distribution was proposed, and the effectiveness of this method was verified with simulations and experiments. Experimental results demonstrated that the measurement accuracy reached 0.64 μm, within the range of 500 mm, with 0.6 mm pitch. Therefore, the light-field time grating can achieve high precision measurement with a low cost and submillimeter period sensing unit.

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