95 research outputs found

    Planar PØP: feature-less pose estimation with applications in UAV localization

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    © 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.We present a featureless pose estimation method that, in contrast to current Perspective-n-Point (PnP) approaches, it does not require n point correspondences to obtain the camera pose, allowing for pose estimation from natural shapes that do not necessarily have distinguished features like corners or intersecting edges. Instead of using n correspondences (e.g. extracted with a feature detector) we will use the raw polygonal representation of the observed shape and directly estimate the pose in the pose-space of the camera. This method compared with a general PnP method, does not require n point correspondences neither a priori knowledge of the object model (except the scale), which is registered with a picture taken from a known robot pose. Moreover, we achieve higher precision because all the information of the shape contour is used to minimize the area between the projected and the observed shape contours. To emphasize the non-use of n point correspondences between the projected template and observed contour shape, we call the method Planar PØP. The method is shown both in simulation and in a real application consisting on a UAV localization where comparisons with a precise ground-truth are provided.Peer ReviewedPostprint (author's final draft

    Research with Collaborative Unmanned Aircraft Systems

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    We provide an overview of ongoing research which targets development of a principled framework for mixed-initiative interaction with unmanned aircraft systems (UAS). UASs are now becoming technologically mature enough to be integrated into civil society. Principled interaction between UASs and human resources is an essential component in their future uses in complex emergency services or bluelight scenarios. In our current research, we have targeted a triad of fundamental, interdependent conceptual issues: delegation, mixed- initiative interaction and adjustable autonomy, that is being used as a basis for developing a principled and well-defined framework for interaction. This can be used to clarify, validate and verify different types of interaction between human operators and UAS systems both theoretically and practically in UAS experimentation with our deployed platforms

    Development of Obstacle Detection System Based On the Integration of Different Based Sensor for Small-Sized UAV

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    Due to the physical size and weight limits of small unmanned aerial vehicles (UAVs), developing a reliable obstacle detection a system that can provide an effective and safe avoidance path is extremely difficult. Prior work has tended to use a vision-based sensor as the primary detecting sensor however, this has resulted in a high reliance on texture appearance and a lack of distance sensing capabilities. Furthermore, due to the inability to detect the free region, vision-based sensor detection systems have difficulty developing a trusted safe avoidance path.  However, most wide spectrum range sensors are bulky and expensive, making them unsuitable for small UAVs. This project aims to construct an obstacles detection system with the integration of various based sensors for a small UAV. The potential obstacles are identified by categorizing feature points identified in image frame. The suggested approach was tested in a real-world setting for both of the observed scenarios, which included various obstacles configurations. Two types of scenarios are experimented in this project consists of single frontal obstacles and presence of side obstacles alongside the frontal obstacles. On top of that, the position of the side obstacle is aligned to the frontal obstacle and then will be positioned in the increment of 20cm further from the frontal obstacle in order to analyse the outcome of the proposed algorithm. The proposed detection system had a possibility to be a trustworthy system even after utilising the depth perception technique, however this does not imply that the proposed system is faultless. The results show that the suggested algorithm system detects and distinguishes between the potential obstacles and free region for a single frontal obstacle perfectly. However, there were improvements that should be implemented with the proposed system's ability of detection for multiple obstacles

    Using Unmanned Aerial Vehicles for Wireless Localization in Search and Rescue

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    This thesis presents how unmanned aerial vehicles (UAVs) can successfully assist in search and rescue (SAR) operations using wireless localization. The zone-grid to partition to capture/detect WiFi probe requests follows the concepts found in Search Theory Method. The UAV has attached a sensor, e.g., WiFi sniffer, to capture/detect the WiFi probes from victims or lost people’s smartphones. Applying the Random-Forest based machine learning algorithm, an estimation of the user\u27s location is determined with a 81.8% accuracy. UAV technology has shown limitations in the navigational performance and limited flight time. Procedures to optimize these limitations are presented. Additionally, how the UAV is maneuvered during flight is analyzed, considering different SAR flight patterns and Li-Po battery consumption rates of the UAV. Results show that controlling the UAV by remote-controll detected the most probes, but it is less power efficient compared to control it autonomously

    Design a Robust RST Controller for Stabilization of a Tri-Copter UAV

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    Research on the tri-rotor aerial robot is due to extra efficiency over other UAV’s regarding stability, power and size requirements. We require a controller to achieve 6-Degree Of Freedom (DOF), for such purpose, we propose the RST controller to operate our tri-copter model. A MIMO model of a tri-copter aerial robot is challenged in the area of control engineering. Ninestates of output control dynamics are treated individually. We designed dynamic controllers to stabilize the parameters of an UAV. The resulting system control algorithm is capable of stabilizing our UAV to perform numerous operations autonomously. The estimation and simulation implemented inMATLAB, Simulink to verify the results. All real flight test results are presented to prove the success of the planned control structure

    A Fully Autonomous Search and Rescue System Using Quadrotor UAV

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    In order to deal with critical missions a growing interest has been shown to the UAVs design. Flying robots are now used fire protection, surveillance and search & rescue (SAR) operations. In this paper, a fully autonomous system for SAR operations using quadrotor UAV is designed. In order to scan the damaged area, speeds up the searching process and detect any possible survivals a new search strategy that combines the standard search strategies with the probability of detection is developed. Furthermore the autopilot is designed using an optimal backstepping controller and this enables the tracking of the reference path with high accuracy and maximizes the flying time. Finally a comparison between the applied strategies is made using a study case of survivals search operation. The obtained results confirmed the efficiency of the designed system

    Implementation of Survivor Detection Strategies Using Drones

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    Survivors stranded during floods tend to seek refuge on dry land. It is important to search for these survivors and help them reach safety as quickly as possible. The terrain in such situations however, is heavily damaged and restricts the movement of emergency personnel towards these survivors. Therefore, it is advantageous to utilize Unmanned Aerial Vehicles (UAVs) in cooperation with on-ground first responders to aid search and rescue efforts. In this article we demonstrate an implementation and improvement of the weight-based path planning algorithm using an off-the-shelf UAV. The coordinates of the survivor and their heading is reported by an on-ground observer to the UAV to generate a weighted map of the surroundings for exploration. Each coordinate in the map is assigned a weight which dictates the priority of exploration. These waypoints are then sorted on the basis of their weights to arrive at an ordered list for exploration by the UAV. We developed the model in MATLAB, followed by prototyping on Robot Operating System (ROS) using a 3DR Iris quadcopter. We tested the model on an off-the-shelf UAV by utilizing the MAVROS and MAVLINK capabilities of ROS. During the implementation of the algorithm on the UAV, several additional factors such as unreliable GPS signals and limited field of view which could effect the performance of the model were in effect, despite which the algorithm performed fairly well. We compared our model with conventional algorithms described in the literature, and showed that our implementation outperforms them.Comment: 22 pages, 42 figures, 2 table
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