Position-Based Visual Servoing of a Micro-Aerial Vehicle Operating Indoor

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Hanoch Efraim ◽  
Amir Shapiro ◽  
Moshe Zohar ◽  
Gera Weiss
Keyword(s):  
Visual Servoing ◽  
3D Model ◽  
Closed Loop ◽  
Specific Problem ◽  
Three Dimensional ◽  
Adaptive Controller ◽  
Single Image ◽  
Micro Aerial Vehicle ◽  
Aerial Vehicle ◽  
Gain Scheduled

In this work, we suggest a novel solution to a very specific problem—calculating the pose (position and attitude) of a micro-aerial vehicle (MAV) operating inside corridors and in front of windows. The proposed method makes use of a single image captured by a front facing camera, of specific features whose three-dimensional (3D) model is partially known. No prior knowledge regarding the size of the corridor or the window is needed, nor is the ratio between their width and height. The position is calculated up to an unknown scale using a gain scheduled iterative algorithm. In order to compensate for the unknown scale, an adaptive controller that ensures consistent closed loop behavior is suggested. The attitude calculation can be used as is, or the results can be fused with angular velocity sensors to achieve better estimation. In this paper, the algorithm is presented and the approach is demonstrated with simulations and experiments.

Assessment of Structure from Motion for reconnaissance augmentation and bandwidth usage reduction

2019 ◽  
Vol 17 (2) ◽  
pp. 213-225
Author(s):  
Jonathan Roeber ◽  
Scott Nykl ◽  
Scott Graham
Keyword(s):  
Structure From Motion ◽  
Virtual World ◽  
3D Model ◽  
Three Dimensional ◽  
Video Stream ◽  
Image Sensors ◽  
Processing Unit ◽  
Aerial Vehicle ◽  
3D Virtual World ◽  
Remote System

Modern militaries rely upon remote image sensors for real-time intelligence. A typical remote system consists of an unmanned aerial vehicle, or UAV, with an attached camera. A video stream is sent from the UAV, through a bandwidth-constrained satellite connection, to an intelligence processing unit. In this research, an upgrade to this remote-video-stream method of collection is proposed. A set of synthetic images of a scene captured by an UAV in a virtual environment is sent to a pipeline of computer vision algorithms, collectively known as Structure from Motion. The output of Structure from Motion, a three-dimensional (3D) model, is then assessed in a 3D virtual world as a possible replacement for the images from which it was created. This study shows Structure from Motion results from a modifiable spiral flight path and compares the geoaccuracy of each result. A flattening of height is observed, and an automated compensation for this flattening is proposed and performed. Each reconstruction is also compressed, and the size of the compression is compared with the compressed size of the images from which it was created. A reduction of 49–60% of required space, or bandwidth, is shown. A corresponding video demonstrating this technique is available online.

Dynamic Visual Servoing for a Quadrotor Using a Virtual Camera

2017 ◽  
Vol 05 (01) ◽  
pp. 1-17 ◽  
Author(s):  
Geoff Fink ◽  
Hui Xie ◽  
Alan F. Lynch ◽  
Martin Jagersand
Keyword(s):  
Visual Servoing ◽  
Closed Loop ◽  
Field Of View ◽  
Visual Features ◽  
Control Law ◽  
Asymptotically Stable ◽  
Globally Asymptotically Stable ◽  
Virtual Camera ◽  
Aerial Vehicle ◽  
Planar Target

This paper presents a dynamic image-based visual servoing (IBVS) control law for a quadrotor unmanned aerial vehicle (UAV) equipped with a single fixed on-board camera. The motion control problem is to regulate the relative position and yaw of the vehicle to a moving planar target located within the camera’s field of view. The control law is termed dynamic as it’s based on the dynamics of the vehicle. To simplify the kinematics and dynamics, the control law relies on the notion of a virtual camera and image moments as visual features. The convergence of the closed-loop is proven to be globally asymptotically stable for a horizontal target. In the case of nonhorizontal targets, we modify the control using a homography decomposition. Experimental and simulation results demonstrate the control law’s performance.

scholarly journals Digital Documentation and a 3-D Model of Beaufort Castle via RTK GNSS, Terrestrial Laser Scanner and UAS-based Photogrammetry

2021 ◽  
Vol 310 ◽  
pp. 05002
Author(s):  
Yousef Naanouh ◽  
Vasyutinskaya Stanislava
Keyword(s):  
Laser Scanning ◽  
3D Model ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Terrestrial Laser Scanning ◽  
Three Dimensional Model ◽  
South Lebanon ◽  
Aerial Vehicle ◽  
Digital Documentation ◽  
D Model

Three-dimensional digital technology is important in the maintenance and monitoring of archeological sites. This paper focuses on using a combination of terrestrial laser scanning and unmanned aerial vehicle (Phantom 4 pro) photogrammetry to establish a three-dimensional model and associated digital documentation of Beaufort castle (Arnoun, South Lebanon). The overall discrepancy between the two technologies was sufficient for the generation of convergent data. Thus, the terrestrial laser scanning and phantom 4 photogrammetry data were aligned and merged post-conversion into compatible extensions. A three-D dimensional (3D) model, with planar and perpendicular geometries, based on the hybrid datapoint cloud was developed. This study demonstrates the potential of using the integration of terrestrial laser scanning and photogrammetry in 3D digital documentation and spatial analysis of the Lebanese archeological sites.

scholarly journals Towards locust-inspired gliding wing prototypes for micro aerial vehicle applications

2021 ◽  
Vol 8 (6) ◽  
pp. 202253
Author(s):  
Hamid Isakhani ◽  
Caihua Xiong ◽  
Wenbin Chen ◽  
Shigang Yue
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
Element Analysis ◽  
Micro Aerial Vehicle ◽  
Maximum Deformation ◽  
Insect Wings ◽  
Wing Structures ◽  
Aerial Vehicle ◽  
Manufacturing Methods ◽  
Locust Wing

In aviation, gliding is the most economical mode of flight explicitly appreciated by natural fliers. They achieve it by high-performance wing structures evolved over millions of years in nature. Among other prehistoric beings, locust is a perfect example of such natural glider capable of endured transatlantic flights that could inspire a practical solution to achieve similar capabilities on micro aerial vehicles. An investigation in this study demonstrates the effects of haemolymph on the flexibility of several flying insect wings proving that many species exist with further simplistic yet well-designed wing structures. However, biomimicry of such aerodynamic and structural properties is hindered by the limitations of modern as well as conventional fabrication technologies in terms of availability and precision, respectively. Therefore, here we adopt finite-element analysis to investigate the manufacturing-worthiness of a three-dimensional digitally reconstructed locust wing, and propose novel combinations of economical and readily available manufacturing methods to develop the model into prototypes that are structurally similar to their counterparts in nature while maintaining the optimum gliding ratio previously obtained in the aerodynamic simulations. The former is assessed here via an experimental analysis of the flexural stiffness and maximum deformation rate as EI s = 1.34 × 10 −4 Nm 2 , EI c = 5.67 × 10 −6 Nm 2 and greater than 148.2%, respectively. Ultimately, a comparative study of the mechanical properties reveals the feasibility of each prototype for gliding micro aerial vehicle applications.

Robust attitude control of the three-dimensional unknown chaotic satellite system

2021 ◽  
pp. 014233122110561
Author(s):  
Muhammad Shafiq ◽  
Israr Ahmad ◽  
O Abdullah Almatroud ◽  
M Mossa Al-Sawalha
Keyword(s):  
Attitude Control ◽  
Closed Loop ◽  
Three Dimensional ◽  
Adaptive Controller ◽  
The State ◽  
Feedback Gain ◽  
State Variables ◽  
Nonlinear Controller ◽  
Model Uncertainties ◽  
Control Effort

This paper proposes a novel continuous-time robust direct adaptive controller for the attitude control of the three-dimensional unknown chaotic spacecraft system. It considers that the plant’s nonlinear terms, exogenous disturbances, and model uncertainties are unknown and bounded; the controller design is independent of the system’s nonlinear terms. These controller attributes flourish the robust performance of the closed-loop and establish smooth state vector convergence to zero. The proposed controller consists of three parts: (1) a linear controller establishes the stability of the closed-loop at the origin, (2) a nonlinear controller component that autonomously adjusts the feedback gain, and (3) a nonlinear adaptive controller compensates for the model uncertainties and external disturbances using the online estimates of bounds and model uncertainties. The output of this part remains within a given upper and lower bound. The feedback controller gain is large when the state variables are away from the origin and become small in the origin’s vicinity. This feature is novel and contributes to the synthesis of smooth control effort that establishes robust fast and oscillation-free convergence of the state variables to zero. The Lyapunov direct stability analysis assures the global asymptotic robust stability of the closed-loop. Computer simulations and comparative analysis are included to verify the theoretical findings.

scholarly journals The Zurich urban micro aerial vehicle dataset

2017 ◽  
Vol 36 (3) ◽  
pp. 269-273 ◽  
Author(s):  
András L Majdik ◽  
Charles Till ◽  
Davide Scaramuzza
Keyword(s):  
Three Dimensional ◽  
Ground Truth ◽  
Ground Level ◽  
Urban Environments ◽  
Sensor Data ◽  
Measurement Unit ◽  
Reconstruction Algorithms ◽  
Ground Truth Data ◽  
Micro Aerial Vehicle ◽  
Aerial Vehicle

This paper presents a dataset recorded on-board a camera-equipped micro aerial vehicle flying within the urban streets of Zurich, Switzerland, at low altitudes (i.e. 5–15 m above the ground). The 2 km dataset consists of time synchronized aerial high-resolution images, global position system and inertial measurement unit sensor data, ground-level street view images, and ground truth data. The dataset is ideal to evaluate and benchmark appearance-based localization, monocular visual odometry, simultaneous localization and mapping, and online three-dimensional reconstruction algorithms for micro aerial vehicles in urban environments.

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