scholarly journals A Vision-Based Method for Autonomous Landing of a Rotor-Craft Unmanned Aerial Vehicle

2006 ◽  
Vol 3 (3) ◽  
pp. 171-177
Author(s):  
Z. Yuan ◽  
Z. Gong ◽  
J. Chen ◽  
J. Wu
Keyword(s):  
Real Time ◽  
Unmanned Aerial Vehicle ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Autonomous Landing ◽  
Linear Algorithm ◽  
Three Dimensional Structure ◽  
Intrinsic Parameters ◽  
Structure Estimation ◽  
Aerial Vehicle

This article introduces a real-time vision-based method for guided autonomous landing of a rotor-craft unmanned aerial vehicle. In the process of designing the pattern of landing target, we have fully considered how to make this easier for simplified identification and calibration. A linear algorithm was also applied using a three-dimensional structure estimation in real time. In addition, multiple-view vision technology is utilized to calibrate intrinsic parameters of camera online, so calibration prior to flight is unnecessary and the focus of camera can be changed freely in flight, thus upgrading the flexibility and practicality of the method.

Vision-based pose estimation of a multi-rotor unmanned aerial vehicle

2019 ◽  
Vol 7 (3) ◽  
pp. 120-132
Author(s):  
Kashish Gupta ◽  
Bara Jamal Emran ◽  
Homayoun Najjaran
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Three Dimensional ◽  
Processing System ◽  
Training Procedure ◽  
Autonomous Landing ◽  
Content Type ◽  
Landing Platform ◽  
Aerial Vehicle ◽  
Autopilot Systems ◽  
Practical Implications

Purpose The purpose of this paper is to facilitate autonomous landing of a multi-rotor unmanned aerial vehicle (UAV) on a moving/tilting platform using a robust vision-based approach. Design/methodology/approach Autonomous landing of a multi-rotor UAV on a moving or tilting platform of unknown orientation in a GPS-denied and vision-compromised environment presents a challenge to common autopilot systems. The paper proposes a robust visual data processing system based on targets’ Oriented FAST and Rotated BRIEF features to estimate the UAV’s three-dimensional pose in real time. Findings The system is able to visually locate and identify the unique landing platform based on a cooperative marker with an error rate of 1° or less for all roll, pitch and yaw angles. Practical implications The proposed vision-based system aims at on-board use and increased reliability without a significant change to the computational load of the UAV. Originality/value The simplicity of the training procedure gives the process the flexibility needed to use a marker of any unknown/irregular shape or dimension. The process can be easily tweaked to respond to different cooperative markers. The on-board computationally inexpensive process can be added to off-the-shelf autopilots.

An Assistant Interface to Design and Produce a Pop-Up Card

2010 ◽  
Vol 1 (2) ◽  
pp. 40-50
Author(s):  
Sosuke Okamura ◽  
Takeo Igarashi
Keyword(s):  
Real Time ◽  
Design Process ◽  
Collision Detection ◽  
User Study ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Design Activity ◽  
Three Dimensional Structure ◽  
Design And Production

This article describes an assistant interface to design and produce pop-up cards. A pop-up card is a piece of folded paper from which a three-dimensional structure pops up when opened. The authors propose an interface to assist the user in the design and production of a pop-up card. During the design process, the system examines whether the parts protrude from the card or whether the parts collide with one another when the card is closed. The user can concentrate on the design activity because the error occurrence and the error resolution are continuously fed to the user in real time. The authors demonstrate the features of their system by creating two pop-up card examples and perform an informal preliminary user study, showing that automatic protrusion and collision detection are effective in the design process.

An Assistant Interface to Design and Produce a Pop-Up Card

2012 ◽  
pp. 119-130
Author(s):  
Sosuke Okamura ◽  
Takeo Igarashi
Keyword(s):  
Real Time ◽  
Design Process ◽  
Collision Detection ◽  
User Study ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Design Activity ◽  
Three Dimensional Structure ◽  
Design And Production

This article describes an assistant interface to design and produce pop-up cards. A pop-up card is a piece of folded paper from which a three-dimensional structure pops up when opened. The authors propose an interface to assist the user in the design and production of a pop-up card. During the design process, the system examines whether the parts protrude from the card or whether the parts collide with one another when the card is closed. The user can concentrate on the design activity because the error occurrence and the error resolution are continuously fed to the user in real time. The authors demonstrate the features of their system by creating two pop-up card examples and perform an informal preliminary user study, showing that automatic protrusion and collision detection are effective in the design process.

The Three-dimensional structure of frozen-hydrated nudaurelia capensis β virus

1987 ◽  
Vol 45 ◽  
pp. 650-651
Author(s):  
N. H. Olson ◽  
T. S. Baker ◽  
Wu Bo Mu ◽  
J. E. Johnson ◽  
D. A. Hendry
Keyword(s):  
South African ◽  
Rna Virus ◽  
Carbon Film ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Electron Dose ◽  
Total Electron ◽  
Three Dimensional Structure ◽  
Negative Stain ◽  
Dimensional Reconstruction

Nudaurelia capensis β virus (NβV) is an RNA virus of the South African Pine Emperor moth, Nudaurelia cytherea capensis (Lepidoptera: Saturniidae). The NβV capsid is a T = 4 icosahedron that contains 60T = 240 subunits of the coat protein (Mr = 61,000). A three-dimensional reconstruction of the NβV capsid was previously computed from visions embedded in negative stain suspended over holes in a carbon film. We have re-examined the three-dimensional structure of NβV, using cryo-microscopy to examine the native, unstained structure of the virion and to provide a initial phasing model for high-resolution x-ray crystallographic studiesNβV was purified and prepared for cryo-microscopy as described. Micrographs were recorded ∼1 - 2 μm underfocus at a magnification of 49,000X with a total electron dose of about 1800 e-/nm2.

Three Dimensional structure and organization of diploid chromosomes by optical section microscopy

1987 ◽  
Vol 45 ◽  
pp. 633-635
Author(s):  
David A. Agard ◽  
Yasushi Hiraoka ◽  
John W. Sedat
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Developmental State ◽  
Mitotic Cell ◽  
Biological Properties ◽  
Dimensional Structure ◽  
Specific Gene ◽  
Three Dimensional Structure ◽  
Complementary Techniques ◽  
Dynamic Structures

In an effort to understand the complex relationship between structure and biological function within the nucleus, we have embarked on a program to examine the three-dimensional structure and organization of Drosophila melanogaster embryonic chromosomes. Our overall goal is to determine how DNA and proteins are organized into complex and highly dynamic structures (chromosomes) and how these chromosomes are arranged in three dimensional space within the cell nucleus. Futher, we hope to be able to correlate structual data with such fundamental biological properties as stage in the mitotic cell cycle, developmental state and transcription at specific gene loci.Towards this end, we have been developing methodologies for the three-dimensional analysis of non-crystalline biological specimens using optical and electron microscopy. We feel that the combination of these two complementary techniques allows an unprecedented look at the structural organization of cellular components ranging in size from 100A to 100 microns.

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