Accurate Calibration for Large-Scale Tracking-Based Visual Measurement System

2021 ◽  
Vol 70 ◽  
pp. 1-11
Author(s):  
Tao Jiang ◽  
Haihua Cui ◽  
Xiaosheng Cheng
ROBOT ◽  
2011 ◽  
Vol 33 (3) ◽  
pp. 299-302 ◽  
Author(s):  
Yi WANG ◽  
Changjie LIU ◽  
Xueyou YANG ◽  
Shenghua YE

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1297
Author(s):  
Viktor Skrickij ◽  
Eldar Šabanovič ◽  
Dachuan Shi ◽  
Stefano Ricci ◽  
Luca Rizzetto ◽  
...  

Railway infrastructure must meet safety requirements concerning its construction and operation. Track geometry monitoring is one of the most important activities in maintaining the steady technical conditions of rail infrastructure. Commonly, it is performed using complex measurement equipment installed on track-recording coaches. Existing low-cost inertial sensor-based measurement systems provide reliable measurements of track geometry in vertical directions. However, solutions are needed for track geometry parameter measurement in the lateral direction. In this research, the authors developed a visual measurement system for track gauge evaluation. It involves the detection of measurement points and the visual measurement of the distance between them. The accuracy of the visual measurement system was evaluated in the laboratory and showed promising results. The initial field test was performed in the Vilnius railway station yard, driving at low velocity on the straight track section. The results show that the image point selection method developed for selecting the wheel and rail points to measure distance is stable enough for TG measurement. Recommendations for the further improvement of the developed system are presented.


Author(s):  
S. Gao ◽  
Z. Ye ◽  
C. Wei ◽  
X. Liu ◽  
X. Tong

<p><strong>Abstract.</strong> The high-speed videogrammetric measurement system, which provides a convenient way to capture three-dimensional (3D) dynamic response of moving objects, has been widely used in various applications due to its remarkable advantages including non-contact, flexibility and high precision. This paper presents a distributed high-speed videogrammetric measurement system suitable for monitoring of large-scale structures. The overall framework consists of hardware and software two parts, namely observation network construction and data processing. The core component of the observation network is high-speed cameras to provide multiview image sequences. The data processing part automatically obtains the 3D structural deformations of the key points from the captured image sequences. A distributed parallel processing framework is adopted to speed up the image sequence processing. An empirical experiment was conducted to measure the dynamics of a double-tube five-layer building structure on the shaking table using the presented videogrammetric measurement system. Compared with the high-accuracy total station measurement, the presented system can achieve a sub-millimeter level of coordinates discrepancy. The 3D deformation results demonstrate the potential of the non-contact high-speed videogrammetric measurement system in dynamic monitoring of large-scale shake table tests.</p>


2018 ◽  
Vol 11 (2) ◽  
pp. 166-180 ◽  
Author(s):  
Long Xin ◽  
Delin Luo ◽  
Han Li

PurposeThe purpose of this paper is to develop a monocular visual measurement system for autonomous aerial refueling (AAR) for unmanned aerial vehicle, which can process images from an infrared camera to estimate the pose of the drogue in the tanker with high accuracy and real-time performance.Design/methodology/approachMethods and techniques for marker detection, feature matching and pose estimation have been designed and implemented in the visual measurement system.FindingsThe simple blob detection (SBD) method is adopted, which outperforms the Laplacian of Gaussian method. And a novel noise-elimination algorithm is proposed for excluding the noise points. Besides, a novel feature matching algorithm based on perspective transformation is proposed. Comparative experimental results indicated the rapidity and effectiveness of the proposed methods.Practical implicationsThe visual measurement system developed in this paper can be applied to estimate the pose of the drogue with a fast speed and high accuracy and it is a feasible measurement strategy which will considerably increase the autonomy and reliability for AAR.Originality/valueThe SBD method is used to detect the features and a novel noise-elimination algorithm is proposed. Besides, a novel feature matching algorithm based on perspective transformation is proposed which is robust and accurate.


2014 ◽  
Vol 532 ◽  
pp. 165-169 ◽  
Author(s):  
Tao Liu ◽  
Lei Wan ◽  
Xing Wei Liang

A monocular vision measurement system was proposed based on the underwater robot, which used a single camera as visual sensor and used inertial navigation system to measure position and attitude. In this paper, the processing of underwater target images and the parameter calibration algorithm for visual measurement system were discussed, and then the visual measurement mathematic model of underwater robot was derived using the pose information of the inertial navigation system. Vision measuring principle validation tests for underwater robot have been carried out to detect underwater targets. The experiments verify that the monocular vision measurement algorithm proposed for underwater robot is effective with a preferably accuracy.


Sign in / Sign up

Export Citation Format

Share Document