Download or read book Tracking of Ground Mobile Targets by Quandrotor Unmanned Aerial Vehicles written by Ruoyu Tan and published by . This book was released on 2013 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: An Unmanned Air Vehicle (UAV) is an aircraft without a human pilot on board. It can be controlled either autonomously by computers onboard, or using a remote control by a pilot on the ground, or in another vehicle. In both military and civilian sectors, UAVs are quickly obtaining popularity and expected to expand dramatically in the years to come. As UAVs gain more attention, one of the immediate requirements would be to have UAVs work as much autonomously as possible. One of the common tasks that UAVs would be engaged in is target tracking which has various potential applications in military field, law-enforcement, wildlife protection effort, and so on. This thesis focuses on development of a controller for UAVs to track ground target. In particular, this thesis focuses on quadrotor UAV, which is a multicopter that is lifted and propelled using four motors. Admittedly, several target tracking control methods have been developed in recent years. However, only a few of them have been applied on a quadrotor. Most of these tracking methods, particularly those based on Proportional Derivative (PD) control laws, which have been applied on quadrotors, are not time efficient due to practical acceleration constraint and a number of parameters that need to be tuned. The UAV control problem can be divided into 4 sub-problems: Position Control, Motor Control, Trajectory Tracking and Trajectory Generation. In this thesis, the dynamic equations of motion for quadrotors and a Proportional Derivative control law is derived to solve the problems of Position Control, Motor Control and Trajectory Tracking. A Proportional Navigation (PN) based switching strategy is proposed to address the problem of Trajectory Generation. The experiments and numerical simulations are performed using non-maneuvering and maneuvering targets. The simulation results show that the proposed PN based switching strategy not only carries out effective tracking but also results into smaller oscillations and errors when compared to the widely used PD tracking method. The switching strategy, as proposed as a solution to target tracking problem, leaves an important question with regard to when should the switching happen. It is intuitive that the time of switching will play a role in how fast the UAV converges to the target. The second problem considered in this thesis relates to the optimal time of switching that would minimize the positional error between the UAV and the target. An optimal switching strategy is proposed to obtain the optimal switching time for both non-maneuvering and maneuvering targets. Analytical solutions that generate trajectories based on PN and PD methods are used in this strategy. The numerical simulations validate the optimality, reliability, and accuracy of the proposed method for both non-maneuvering and maneuvering targets.
Download or read book On Autonomous Target Tracking for UAVs written by Panagiotis Theodorakopoulos and published by . This book was released on 2009 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most applications of Unmanned Aerial Vehicles are related to events that occur on the ground. In particular, ground target tracking, be the target static, slowly moving or maneuvering at high speeds, is an essential task for UAVs. The overall objective of this thesis is to provide methods to endow a drone to autonomously track a moving ground target, under the following conditions: - A fixed wing UAV equipped with a monocular camera. - Presence of obstacles that hinder ground visibility. - No Fly Zones that limit the airspace. - Restrictions on the field of view of the observing sensor (a camera) - Various target dynamics and behavior: the target may be either moving on an open field or on a road network, and also has dynamic constraints (e.g. if it is a car). It can be neutral or evasive: in the latter case, it can exploit the presence of obstacles, denoted as "shadows" to avoid being tracked by the UAV, making the problem akin to a "hide and seek" game. The thesis proposes three approaches to tackle this problem: - A control based navigation method, - An adversarial predictive method, - And a discrete game theoretic approach. Results obtained in realistic simulations and with an actual UAV are presented to evaluate and compare the pros and cons of each approach. Extensions to the multi-drone case are also considered.
Download or read book Study on the Tracking of a Ground Mobile Object by a Quadrotor written by Laura López Jiménez and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The study done in this paper consists in developing a trajectory control algorithm for a quadcopter in order to follow the movement of a ground mobile object. To achieve the goal, control systems for Pitch and Roll linear speed have been de-signed in a way that allow the drone to a stable flying. The conceptual technical requirements to do this are embodied in the course of control placed in the 6th semester of the Electronic and Automatic Engineering degree. The main part of the current study is devoted to the implementation of the neces-sary algorithms related to the good control of an object in motion. Imaging pro-cessing techniques have been revealed as fundamental in pursuing the former task. The quadcopter used for the experiments was a Parrot AR Drone 2.0. The Drone communicates with the computer using WI-FI network. To establish connection between the computer and the Drone, it was necessary to use two operating sys-tems: Linux and Robot Operating System (ROS). The functions that control the Drone have been implemented by using MATLAB and Simulink Tool. The study is structured in three main parts: the first gathers all the system identi-fication process in order to design the speed linear controllers. The second part refers to the calibration parameters identification and image processing and the final one, is devoted to implement the persecution algorithm and the final results.
Download or read book Unmanned Aerial Vehicle Path Planning for Detection of Mobile Targets written by Douglas Brown and published by . This book was released on 2018 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents work on mobile target detection using Unmanned Aerial Vehicles. A novel dynamic progressively-spiral-out (PSO) path is used for a team of unmanned aerial vehicles (UAVs) to perform an exhaustive search of mobile ground targets. Two novel procedures are designed for a UAV to be inserted into and removed from an established PSO formation without discontinuing the confidence area. A comparison study in simulation was conducted using both randomly moving and smart avoidance targets. The results show the effectiveness of the proposed approaches. The results compare the PSO path to a baseline raster path. The PSO path outperforms the raster path on time to detection of mobile targets, detection rate of smart avoidance targets, and detection rate of intrusive attacking targets. Future work with path planning and machine learning is also presented.
Download or read book Proceedings of the 5th International Conference on Electrical Engineering and Control Applications Volume 1 written by Salim Ziani and published by Springer Nature. This book was released on with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precision Landing of a Quadrotor UAV on a Moving Target Using Low cost Sensors written by Kevin Ling and published by . This book was released on 2014 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the use of unmanned aerial vehicles (UAVs) becoming more widespread, a need for precise autonomous landings has arisen. In the maritime setting, precise autonomous landings will help to provide a safe way to recover UAVs deployed from a ship. On land, numerous applications have been proposed for UAV and unmanned ground vehicle (UGV) teams where autonomous docking is required so that the UGVs can either recover or service a UAV in the field. Current state of the art approaches to solving the problem rely on expensive inertial measurement sensors and RTK or differential GPS systems. However, such a solution is not practical for many UAV systems. A framework to perform precision landings on a moving target using low-cost sensors is proposed in this thesis. Vision from a downward facing camera is used to track a target on the landing platform and generate high quality relative pose estimates. The landing procedure consists of three stages. First, a rendezvous stage commands the quadrotor on a path to intercept the target. A target acquisition stage then ensures that the quadrotor is tracking the landing target. Finally, visual measurements of the relative pose to the landing target are used in the target tracking stage where control and estimation are performed in a body-planar frame, without the use of GPS or magnetometer measurements. A comprehensive overview of the control and estimation required to realize the three stage landing approach is presented. Critical parts of the landing framework were implemented on an AscTec Pelican testbed. The AprilTag visual fiducial system is chosen for use as the landing target. Implementation details to improve the AprilTag detection pipeline are presented. Simulated and experimen- tal results validate key portions of the landing framework. The novel relative estimation scheme is evaluated in an indoor positioning system. Tracking and landing on a moving target is demonstrated in an indoor environment. Outdoor tests also validate the target tracking performance in the presence of wind.
Download or read book Colour based Object Detection and Tracking for an Autonomous Quadrotor written by Hani Hunud Abia Kadouf and published by . This book was released on 2014 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Useful applications of Unmanned Air Vehicles (UAVs) include aerial surveillance in hostile military zones or search and rescue operations in disaster stricken areas. The increased visual capacity of UAVs also helps support ground vehicles during scouting missions or to extend communication beyond insurmountable land or water barriers. Computer vision techniques provide a simplistic means to convey information for motion control of a UAV. Hence this work focuses on the development of a vision based image processing algorithm for autonomous navigation of a quadrotor UAV. A camera was used to capture an aerial field of view and transmit a video stream of its perspective to a base station- where OpenCV 2.3.1 vision processing software was used to implement a vision processing algorithm. The algorithm comprises of colour thresholding, the use of image moment and blob detection to detect and track an object within the camea view. Experimental readings of an object's displacement at three altitudes; 1.5m, 2.0m and 2.5m were used to derive pixel-to-cm conversion equations based on the target's pixel coordinates on the viewing window. Through a statistical analysis of variance and standard deviation conducted on 15 experimental readings of displacement ranging from 5cm to 25cm; it was shown that the vision system is best suited for tracking displacements at lower altitude flights. Hence, the best result for variance and standard were achieved when using the derived equation and were 0.64 and 0.8 respectively. The equation derived was also used to derive GPS locking coordinates. Pixel coordinates of a target on the camera display were then used to produce GPS locking coordinates for the quadrotor to track a target object.
Download or read book Real time Implementation of an Asynchronous Vision based Target Tracking System in an Unmanned Aerial Vehicle written by and published by . This book was released on 2007 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently, small unmanned aerial vehicles developed by NPS have been able to locate and track stationary and moving targets on the ground. New methods of continuous target tracking are always being developed to improve speed and accuracy, ultimately aiding the user of the system. This thesis describes one such method, utilizing an open loop filter as well as an external correction source: Perspective View Nascent Technologies (PVNT). While the PVNT correction can theoretically improve the accuracy from 20-30 meters to 1-2 meters, it does have a disadvantage in that the target position updates are delayed anywhere from 1-10 seconds. In order to account for the delay, an asynchronous filter is used to update the target position data given the external position correction from PVNT. Two cases have been tested including the general filter and one that utilizes a road model in the calculations. While an earlier thesis developed the basic simulation for the system, this thesis discusses improvements and corrections to the simulation model as well as the necessary steps for real-time implementation.
Download or read book Robust Tracking of Dynamic Targets with Aerial Vehicles Using Quaternion based Techniques written by Hernán Abaunza Gonzalez and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this thesis work is to design control and navigation algorithms for tracking of dynamic ground targets using aerial vehicles. Quaternions, which provide an alternative to the classical representations of aerial vehicle dynamics, have been chosen as a basement to develop robust controllers and agile navigation algorithm, due to their advantages such as the absence of singularities and discontinuities and their mathematical simplicity when handling rotations. The quaternion-based control approaches explored in this thesis range from state feedback, passivity, and energy-based controllers, up to sliding modes, and three-dimensional saturation approaches. Then, autonomous and semi-autonomous navigation strategies for quadrotors were explored. An algorithm has been developed for controlling a quadrotor using gestures from a user wearing an armband. To facilitate the operation of multirotors in adverse scenarios, an aggressive deployment strategy has been proposed where a quadrotor is launched by hand With its motors turned off. Finally, autonomous navigation techniques for tracking dynamic targets have been designed. A trajectory generation algorithm based on differential equations has been introduced to track a land vehicle while describing circles. Finally a distributed path planning algorithm has been developed for a fleet of drones to autonomously track ground targets by solving an online optimization problem.
Download or read book Computer Vision Systems written by Dimitrios Tzovaras and published by Springer Nature. This book was released on 2019-11-22 with total page 799 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 12th International Conference on Computer Vision Systems, ICVS 2019, held in Thessaloniki, Greece, in September 2019. The 72 papers presented were carefully reviewed and selected from 114 submissions. The papers are organized in the following topical sections; hardware accelerated and real time vision systems; robotic vision; vision systems applications; high-level and learning vision systems; cognitive vision systems; movement analytics and gesture recognition for human-machine collaboration in industry; cognitive and computer vision assisted systems for energy awareness and behavior analysis; and vision-enabled UAV and counter UAV technologies for surveillance and security of critical infrastructures.
Download or read book An Examination of Latency and Degradation Issues in Unmanned Combat Aerial Vehicle Environments written by Shane A. Dougherty and published by . This book was released on 2002 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are two basic ways to control an Unmanned Combat Aerial Vehicle (UCAV) as it searches for targets: allow the UCAV to act autonomously or employ man-in-the-loop control. There are also two target sets of interest: fixed or mobile targets. This research focuses on UCAV-based targeting of mobile targets using man-in-the-loop control. In particular, the interest is in how levels of satellite signal latency or signal degradation affect the ability to accurately track, target, and attack mobile targets. This research establishes a weapon effectiveness model assessing targeting inaccuracies as a function of signal latency and/or signal degradation. The research involved three phases. The first phase in the research was to identify the levels of signal latency associated with satellite communications. A literature review, supplemented by interviews with UAV operators, provided insight into the expected range latency values. The second phase of the research identified those factors whose value, in the presence of satellite signal latency, could influence targeting errors during UCAV employment. The final phase involved developing and testing a weapon effectiveness model explicitly modeling satellite signal latency in UCAV targeting against mobile targets. This phase included an effectiveness analysis study.
Download or read book Position Control of an Unmanned Aerial Vehicle From a Mobile Ground Vehicle written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Quadcopters have been developed with controls providing good maneuverability, simple mechanics, and the ability to hover, take-off and land vertically with precision. Due to their small size, they can get close to targets of interest and furthermore stay undetected at lower heights. The main drawbacks of a quadcopter are its high-power consumption and payload restriction, due to which, the number of onboard sensors is constrained. To overcome this limitation, vision-based localization techniques and remote control for the quadcopter are essential areas of current research. The core objective of this research is to develop a closed loop feedback system between an Unmanned Aerial Vehicle (UAV) and a mobile ground vehicle. With this closed loop system, the moving ground vehicle aims to navigate the UAV remotely. The ground vehicle uses a pure pursuit algorithm to traverse a pre-defined path. A Proportional-Integral-Derivative (PID) controller is actualized for position control and attitude stabilization of the UAV. The issue of tracking and 3D pose-estimation of the UAV in light of vision sensing is explored. An estimator to track the states of the UAV, utilizing the images obtained from a single camera mounted on the ground vehicle is developed. This estimator coupled with a Kalman filter determines the UAV's three dimensional position. The relative position of the UAV with the moving ground vehicle and the control output from a joint centralized PD controller is used to navigate the UAV and follow the motion of the ground vehicle in closed loop to avoid time delays. This closed loop system is simulated in MATLAB and Simulink to validate the proposed control and estimation approach. The results obtained validate the control architecture proposed to attain closed loop feedback between the UAV and the mobile ground vehicle.
Download or read book Tracking Ground Targets with Measurements Obtained from a Single Monocular Camera Mounted on an Unmanned Aerial Vehicle written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The core objective of this research is to develop an estimator capable of tracking the states of ground targets with observation measurements obtained from a single monocular camera mounted on a small unmanned aerial vehicle (UAV). Typical sensors on a small UAV include an inertial measurement unit (IMU) with three axes accelerometer and rate gyro sensors and a global positioning system (GPS) receiver which gives position and velocity estimates of the UAV. Camera images are combined with these measurements in state estimate filters to track ground features of opportunity and a target. The images are processed by a keypoint detection and matching algorithm that returns pixel coordinates for the features. Kinematic state equations are derived that reflect the relationships between the available input and output measurements and the states of the UAV, features, and target. These equations are used in the development of coupled state estimators for the dynamic state of the UAV, for estimation of feature positions, and for estimation of target position and velocity. The estimator developed is tested in MATLAB/SIMULINK, where GPS and IMU data are generated from the simulated states of a nonlinear model of a Navion aircraft. Images are also simulated based upon a fabricated environment consisting of features and a moving ground target. Target observability limitations are overcome by constraining the target vehicle to follow ground terrain, defined by local features, and subsequent modification of the target's observation model. An unscented Kalman filter (UKF) provides the simultaneous localization and mapping solution for the estimation of aircraft states and feature locations. Another filter, a loosely coupled Kalman filter for the target states, receives 3D measurements of target position with estimated covariance obtained by an unscented transformation (UT). The UT uses the mean and covariance from the camera measurements and from the UKF estimated aircraft states and feature locations to determine the estimated target mean and covariance. Simulation results confirm that the new loosely coupled filters are capable of estimating target states. Experimental data, collected from a research UAV, explores the effectiveness of the terrain estimation techniques required for target tracking.
Download or read book Advanced Robust Nonlinear Control Approaches for Quadrotor Unmanned Aerial Vehicle written by Moussa Labbadi and published by Springer Nature. This book was released on 2021-09-14 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book studies selected advanced flight control schemes for an uncertain quadrotor unmanned aerial vehicle (UAV) systems in the presence of constant external disturbances, parametric uncertainties, measurement noise, time-varying external disturbances, and random external disturbances. Furthermore, in all the control techniques proposed in this book, it includes the simulation results with comparison to other nonlinear control schemes recently developed for the tracking control of a quadrotor UAV. The main contributions of the present book for quadrotor UAV systems are as follows: (i) the proposed control methods are based on the high-order sliding mode controller (SMC) and hybrid control algorithm with an optimization method. (ii) the finite-time control schemes are developed by using fast terminal SMC (FTSMC), nonsingular FTSMC (NFTSMC), global time-varying SMC, and adaptive laws. (iii) the fractional-order flight control schemes are developed by using the fractional-order calculus theory, super twisting algorithm, NFTSMC, and the SMC. This book covers the research history and importance of quadrotor system subject to system uncertainties, external wind disturbances, and noise measurements, as well as the research status of advanced flight control methods, adaptive flight control methods, and flight control based on fractional-order theory. The book would be interesting to most academic undergraduate, postgraduates, researchers on flight control for drones and applications of advanced controllers in engineering field. This book presents a must-survey for advanced finite-time control for quadrotor system. Some parts of this book have the potential of becoming the courses for the modelling and control of autonomous flying machines. Readers (academic researcher, undergraduate student, postgraduate student, MBA/executive, and education practitioner) interested in nonlinear control methods find this book an investigation. This book can be used as a good reference for the academic research on the control theory, drones, terminal sliding mode control, and related to this or used in Ph.D. study of control theory and their application in field engineering.
Download or read book Proceedings of 3rd International Conference on Artificial Intelligence Robotics and Communication written by Sanjay Yadav and published by Springer Nature. This book was released on with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Mobile Robotics written by DaeEun Kim and published by MDPI. This book was released on 2020-03-06 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mobile robotics is a challenging field with great potential. It covers disciplines including electrical engineering, mechanical engineering, computer science, cognitive science, and social science. It is essential to the design of automated robots, in combination with artificial intelligence, vision, and sensor technologies. Mobile robots are widely used for surveillance, guidance, transportation and entertainment tasks, as well as medical applications. This Special Issue intends to concentrate on recent developments concerning mobile robots and the research surrounding them to enhance studies on the fundamental problems observed in the robots. Various multidisciplinary approaches and integrative contributions including navigation, learning and adaptation, networked system, biologically inspired robots and cognitive methods are welcome contributions to this Special Issue, both from a research and an application perspective.
Download or read book Autonomous Visual Tracking of Stationary Targets Using Small Unmanned Aerial Vehicles written by Robert A. Prince and published by . This book was released on 2004-06 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt:
