scholarly journals A fully automatic calibration framework for navigated ultrasound imaging

2010 ◽  
Author(s):  
M Peterhans ◽  
S Anderegg ◽  
P Gaillard ◽  
T Oliveira-Santos ◽  
S Weber
Keyword(s):  
Ultrasound Imaging ◽  
Automatic Calibration ◽  
Fully Automatic ◽  
Navigated Ultrasound

scholarly journals A Fully Automatic Calibration System for Hydrometers in NIM

MAPAN ◽  
2021 ◽  
Author(s):  
Jintao Wang ◽  
Xiang Liu ◽  
Wencai Shi ◽  
Changhong Xu
Keyword(s):  
Full Range ◽  
Density Measurement ◽  
Fused Silica ◽  
Automatic Calibration ◽  
Liquid Density ◽  
Calibration Data ◽  
Calibration System ◽  
Solid Density ◽  
Fully Automatic ◽  
Better Than

AbstractHydrometers are widely used in industry for liquid density measurement. It is important to achieve rapid and high accuracy calibration for hydrometers. Based on the Archimedes principle, a fully automatic hydrometer calibration system in NIM was designed using Cuckow’s method. The liquid density of n-tridecane (C13H28)is calibrated with 441 g high-purity fused silica ring as the solid density standard. The buoyancy of hydrometer is measured by static weighing system with resolution 0.01 mg. The alignment between liquid surface and hydrometer scale was achieved by the lifting platform with the positioning accuracy of 10 μm. According to the weighing value of hydrometer in air and liquid, the density correction value at different scales is calculated. Hydrometer covering a full range (650–1500) kg/m3can be calibrated without changing the liquid. Taking the calibration data of PTB as reference, the experimental data show that the measurement uncertainty of this system is better than 0.3 division (k = 2).

3D visualization of strain in abdominal aortic aneurysms based on navigated ultrasound imaging

2007 ◽  
Author(s):  
Reidar Brekken ◽  
Jon Harald Kaspersen ◽  
Geir Arne Tangen ◽  
Torbjørn Dahl ◽  
Toril A. N. Hernes ◽  
...  
Keyword(s):  
Ultrasound Imaging ◽  
3D Visualization ◽  
Abdominal Aortic Aneurysms ◽  
Aortic Aneurysms ◽  
Abdominal Aortic ◽  
Navigated Ultrasound

scholarly journals Fully Automatic Calibration of Tumor-Growth Models Using a Single mpMRI Scan

2021 ◽  
Vol 40 (1) ◽  
pp. 193-204
Author(s):  
Klaudius Scheufele ◽  
Shashank Subramanian ◽  
George Biros
Keyword(s):  
Tumor Growth ◽  
Growth Models ◽  
Automatic Calibration ◽  
Tumor Growth Models ◽  
Fully Automatic

scholarly journals Holographic Micromirror Array with Diffuse Areas for Accurate Calibration of 3D Light-Field Display

2020 ◽  
Vol 10 (20) ◽  
pp. 7188
Author(s):  
Lode Jorissen ◽  
Ryutaro Oi ◽  
Koki Wakunami ◽  
Yasuyuki Ichihashi ◽  
Gauthier Lafruit ◽  
...  
Keyword(s):  
Light Field ◽  
3D Visualization ◽  
Calibration Method ◽  
Automatic Calibration ◽  
Display System ◽  
Extrinsic Parameters ◽  
Calibration Algorithm ◽  
Fully Automatic ◽  
Intrinsic And Extrinsic Parameters ◽  
Micromirror Array

Light field 3D displays require a precise alignment between the display source and the micromirror-array screen for error free 3D visualization. Hence, calibrating the system using an external camera becomes necessary, before displaying any 3D contents. The inter-dependency of the intrinsic and extrinsic parameters of display-source, calibration-camera, and micromirror-array screen, makes the calibration process very complex and error-prone. Thus, several assumptions are made with regard to the display setup, in order to simplify the calibration. A fully automatic calibration method based on several such assumptions was reported by us earlier. Here, in this paper, we report a method that uses no such assumptions, but yields a better calibration. The proposed method adapts an optical solution where the micromirror-array screen is fabricated as a computer generated hologram with a tiny diffuser engraved at one corner of each elemental micromirror in the array. The calibration algorithm uses these diffusing areas as markers to determine the relation between the pixels of display source and the mirrors in the micromirror-array screen. Calibration results show that virtually reconstructed 3D scenes align well with the real world contents, and are free from any distortion. This method also eliminates the position dependency of display source, calibration-camera, and mirror-array screen during calibration, which enables easy setup of the display system.

A vision-based fully-automatic calibration method for hand-eye serial robot

2015 ◽  
Vol 42 (1) ◽  
pp. 64-73 ◽  
Author(s):  
Haixia Wang ◽  
Xiao Lu ◽  
Zhanyi Hu ◽  
Yuxia Li
Keyword(s):  
Design Methodology ◽  
Calibration Method ◽  
Automatic Calibration ◽  
Screw Axis ◽  
Robot System ◽  
Camera System ◽  
Content Type ◽  
Serial Robot ◽  
Fully Automatic ◽  
Robot Body

Purpose – The purpose of this paper is to present a fully automatic calibration method for hand-eye serial robot system is presented in this paper. The so-called “fully automatic” is meant to calibrate the robot body, the hand-eye relation, and the used measuring binocular system at the same time. Design/methodology/approach – The calibration is done by controlling the joints to rotate several times one by one in the reverse order (i.e. from the last one to the first one), and simultaneously take pictures of the checkerboard patterns by the stereo camera system attached on the end-effector, then the whole robot system can be calibrated automatically from these captured images. In addition, a nonlinear optimization step is used to further refine the calibration results. Findings – The proposed method is essentially based on an improved screw axis identification method, and it needs only a mirror and some paper checkerboard patterns without resorting to any additional costly measuring instrument. Originality/value – Simulations and real experiments on MOTOMAN-UP6 robot system demonstrate the feasibility and effectiveness of the proposed method.

scholarly journals Automatic Wheels and Camera Calibration for Monocular and Differential Mobile Robots

2021 ◽  
Vol 11 (13) ◽  
pp. 5806
Author(s):  
Konstantin Chaika ◽  
Anton Filatov ◽  
Artyom Filatov ◽  
Kirill Krinkin
Keyword(s):  
Camera Calibration ◽  
Normal Operation ◽  
Automatic Calibration ◽  
Test Results ◽  
Suggested Approach ◽  
Relevant Today ◽  
Fully Automatic ◽  
Using Data ◽  
Two Stages ◽  
Marked Area

Mobile robotic systems are highly relevant today in various fields, both in an industrial environment and in terms of their applications in medicine. After assembling the robot, components such as the camera and wheels need to be calibrated. This requires human participation and depends on human factors. The article describes the approach to fully automatic calibration of a robot’s camera and wheels with a subsequent calibration refinement during the operation. It consists of placing the robot in an inaccurate position, but in a pre-marked area, and using data from the camera, information about the environment configuration, as well as the ability to move, in order to perform calibration without external observers or human participation. There are two stages in this process: the camera and the wheel calibrations. The camera calibration collects the necessary set of images by automatically moving the robot in front of the fiducial markers template, and then moving it on the marked floor, assessing its trajectory curvature. Upon calibration completion, the robot automatically moves to the area of its normal operation and it is proposed to refine the calibration during its operation without blocking its work. The suggested approach was experimentally tested on the Duckietown project base. Based on test results, the approach proved to be comparable to manual calibrations and is capable of replacing a human for this task.

scholarly journals ToF/RGB Sensor Fusion for Augmented 3D Endoscopy using a Fully Automatic Calibration Scheme

2012 ◽  
pp. 111-116
Author(s):  
Sven Haase ◽  
Christoph Forman ◽  
Thomas Kilgus ◽  
Roland Bammer ◽  
Lena Maier-Hein ◽  
...  
Keyword(s):  
Sensor Fusion ◽  
Automatic Calibration ◽  
Calibration Scheme ◽  
Fully Automatic
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