Results 41-60 of 76.
Bookmark and Share    
Full Text
Peer Reviewed
See detailThe NOAH Project: Giving a Chance to Threatened Species in Africa with UAVs
Olivares Mendez, Miguel Angel UL; Bissyandé, Tegawendé; Somasundar, Kannan et al

in Bissyandé, Tegawendé F.; van Stam, Gertjan (Eds.) e-Infrastructure and e-Services for Developing Countries (2014)

Organized crime now targets one of the most precious wealth in Africa, the wild life. The most affected by the poaching are the Big 5, whose survival requires attention and efforts from everyone, in ... [more ▼]

Organized crime now targets one of the most precious wealth in Africa, the wild life. The most affected by the poaching are the Big 5, whose survival requires attention and efforts from everyone, in accordance to his own expertise. Just as Noah (A patriarchal character in Abrahamic religions) was tasked to save every species from the Genesis flood, we envision the NOAH Project to (re)make natural parks as a safe haven. This endeavor requires efficient and effective surveillance which is now facilitated by the use of UAVs. We take this approach further by proposing the use of ICT algorithms to automate surveillance. The proposed intelligent system could inspect a bigger area, recognize potential threats and be manage by non-expert users, reducing the expensive resources that are needed by developing countries to address the problem. [less ▲]

Detailed reference viewed: 174 (12 UL)
Full Text
Peer Reviewed
See detailModeling and Control of Aerial Manipulation Vehicle with Visual sensor
Kannan, Somasundar UL; Olivares Mendez, Miguel Angel UL; Voos, Holger UL

in Second Workshop on Research, Development and Education on Unmanned Aerial Systems (RED-UAS 2013) (2013, November)

Modeling and control of a Quadrotor with robotic arm which uses vision sensor is discussed. A quadrotor model coupled with a two link manipulator is first developed and then the integrated control ... [more ▼]

Modeling and control of a Quadrotor with robotic arm which uses vision sensor is discussed. A quadrotor model coupled with a two link manipulator is first developed and then the integrated control mechanism is investigated. An Image Based Visual Servo system is introduced and then used with the aerial manipulator to successfully perform specific tasks of positioning and stabilization during manipulation. [less ▲]

Detailed reference viewed: 238 (22 UL)
Full Text
Peer Reviewed
See detailCross-Entropy Optimization for Scaling Factors of a Fuzzy Controller: A See-and-Avoid Approach for Unmanned Aerial Systems
Olivares Mendez, Miguel Angel UL; Mejias, Luis; Campoy, Pascual et al

in Journal of Intelligent & Robotic Systems (2013), 69(1-4), 189-205

The Cross-Entropy (CE) is an efficient method for the estimation of rare-event probabilities and combinatorial optimization. This work presents a novel approach of the CE for optimization of a Soft ... [more ▼]

The Cross-Entropy (CE) is an efficient method for the estimation of rare-event probabilities and combinatorial optimization. This work presents a novel approach of the CE for optimization of a Soft-Computing controller. A Fuzzy controller was designed to command an unmanned aerial system (UAS) for avoiding collision task. The only sensor used to accomplish this task was a forward camera. The CE is used to reach a near-optimal controller by modifying the scaling factors of the controller inputs. The optimization was realized using the ROS-Gazebo simulation system. In order to evaluate the optimization a big amount of tests were carried out with a real quadcopter. [less ▲]

Detailed reference viewed: 113 (9 UL)
Full Text
Peer Reviewed
See detailAutonomous Landing of an Unmanned Aerial Vehicle using Image-Based Fuzzy Control
Olivares Mendez, Miguel Angel UL; Mondragon, Ivan; Campoy, Pascual

in Second Workshop on Research, Development and Education on Unmanned Aerial Systems (RED-UAS 2013) (2013)

This paper presents a vision based autonomous landing control approach for unmanned aerial vehicles (UAV). The 3D position of an unmanned helicopter is estimated based on the homographies estimated of a ... [more ▼]

This paper presents a vision based autonomous landing control approach for unmanned aerial vehicles (UAV). The 3D position of an unmanned helicopter is estimated based on the homographies estimated of a known landmark. The translation and altitude estimation of the helicopter against the helipad position are the only information that is used to control the longitudinal, lateral and descend speeds of the vehicle. The control system approach consists in three Fuzzy controllers to manage the speeds of each 3D axis of the aircraft’s coordinate system. The 3D position estimation was proven first, comparing it with the GPS + IMU data with very good results. The robust of the vision algorithm against occlusions was also tested. The excellent behavior of the Fuzzy control approach using the 3D position estimation based in homographies was proved in an outdoors test using a real unmanned helicopter. [less ▲]

Detailed reference viewed: 97 (7 UL)
Full Text
Peer Reviewed
See detailUAS see-and-avoid strategy using a fuzzy logic controller optimized by Cross-Entropy in Scaling Factors and Membership Functions
Fu, Changhong; Olivares Mendez, Miguel Angel UL; Campoy, P. et al

in Unmanned Aircraft Systems (ICUAS), 2013 International Conference on (2013)

This work aims to develop a novel Cross-Entropy (CE) optimization-based fuzzy controller for Unmanned Aerial Monocular Vision-IMU System (UAMVIS) to solve the seeand-avoid problem using its accurate ... [more ▼]

This work aims to develop a novel Cross-Entropy (CE) optimization-based fuzzy controller for Unmanned Aerial Monocular Vision-IMU System (UAMVIS) to solve the seeand-avoid problem using its accurate autonomous localization information. The function of this fuzzy controller is regulating the heading of this system to avoid the obstacle, e.g. wall. In the Matlab Simulink-based training stages, the Scaling Factor (SF) is adjusted according to the specified task firstly, and then the Membership Function (MF) is tuned based on the optimized Scaling Factor to further improve the collison avoidance performance. After obtained the optimal SF and MF, 64% of rules has been reduced (from 125 rules to 45 rules), and a large number of real flight tests with a quadcopter have been done. The experimental results show that this approach precisely navigates the system to avoid the obstacle. To our best knowledge, this is the first work to present the optimized fuzzy controller for UAMVIS using Cross-Entropy method in Scaling Factors and Membership Functions optimization. [less ▲]

Detailed reference viewed: 106 (8 UL)
Full Text
Peer Reviewed
See detailMAVwork: A Framework for Unified Interfacing between Micro Aerial Vehicles and Visual Controllers
Mellado-Bataller, Ignacio; Pestana, Jesús; Olivares Mendez, Miguel Angel UL et al

in Lee, Sukhan; Yoon, Kwang-Joon; Lee, Jangmyung (Eds.) Frontiers of Intelligent Autonomous Systems (2013)

Debugging control software for Micro Aerial Vehicles (MAV) can be risky out of the simulator, especially with professional drones that might harm people around or result in a high bill after a crash. We ... [more ▼]

Debugging control software for Micro Aerial Vehicles (MAV) can be risky out of the simulator, especially with professional drones that might harm people around or result in a high bill after a crash. We have designed a framework that enables a software application to communicate with multiple MAVs from a single unified interface. In this way, visual controllers can be first tested on a low-cost harmless MAV and, after safety is guaranteed, they can be moved to the production MAV at no additional cost. The framework is based on a distributed architecture over a network. This allows multiple configurations, like drone swarms or parallel processing of drones' video streams. Live tests have been performed and the results show comparatively low additional communication delays, while adding new functionalities and flexibility. This implementation is open-source and can be downloaded from github.com/uavster/mavwork [less ▲]

Detailed reference viewed: 94 (0 UL)
Full Text
Peer Reviewed
See detailA Hierarchical Tracking Strategy for Vision-Based Applications On-Board UAVs
Martínez, Carol; Mondragón, Iván; Campoy, Pascual et al

in Journal of Intelligent & Robotic Systems (2013), 72(3-4), 517-539

In this paper, we apply a hierarchical tracking strategy of planar objects (or that can be assumed to be planar) that is based on direct methods for vision-based applications on-board UAVs. The use of ... [more ▼]

In this paper, we apply a hierarchical tracking strategy of planar objects (or that can be assumed to be planar) that is based on direct methods for vision-based applications on-board UAVs. The use of this tracking strategy allows to achieve the tasks at real-time frame rates and to overcome problems posed by the challenging conditions of the tasks: e.g. constant vibrations, fast 3D changes, or limited capacity on-board. The vast majority of approaches make use of featurebased methods to track objects. Nonetheless, in this paper we show that although some of these feature-based solutions are faster, direct methods can be more robust under fast 3D motions (fast changes in position), some changes in appearance, constant vibrations (without requiring any specific hardware or software for video stabilization), and situations in which part of the object to track is outside of the field of view of the camera. The performance of the proposed tracking strategy onboard UAVs is evaluated with images from realflight tests using manually-generated ground truthinformation, accurate position estimation using a Vicon system, and also with simulated data from a simulation environment. Results show that the hierarchical tracking strategy performs better than well-known feature-based algorithms and wellknown configurations of direct methods, and that its performance is robust enough for vision-in-theloop tasks, e.g. for vision-based landing tasks. [less ▲]

Detailed reference viewed: 156 (4 UL)
Full Text
Peer Reviewed
See detailReal-time Adaptive Multi-Classifier Multi-Resolution Visual Tracking Framework for Unmanned Aerial Vehicles
Fu, Changhong; Suarez-Fernandez, Ramon; Olivares Mendez, Miguel Angel UL et al

in Second Workshop on Research, Development and Education on Unmanned Aerial Systems (RED-UAS 2013) (2013)

This paper presents a novel robust visual tracking framework, based on discrimi- native method, for Unmanned Aerial Vehicles (UAVs) to track an arbitrary 2D/3D target at real-time frame rates, that is ... [more ▼]

This paper presents a novel robust visual tracking framework, based on discrimi- native method, for Unmanned Aerial Vehicles (UAVs) to track an arbitrary 2D/3D target at real-time frame rates, that is called the Adaptive Multi-Classifier Multi-Resolution (AMCMR) framework. In this framework, adaptive Multiple Classifiers (MC) are updated in the (k- 1)th frame-based Multiple Resolutions (MR) structure with compressed positive and negative samples, and then applied them in the kth frame-based Multiple Resolutions (MR) structure to detect the current target. The sample importance has been integrated into this framework to improve the tracking stability and accuracy. The performance of this framework was evaluated with the Ground Truth (GT) in different types of public image databases and real flight- based aerial image datasets firstly, then the framework has been applied in the UAV to inspect the Offshore Floating Platform (OFP). The evaluation and application results show that this framework is more robust, efficient and accurate against the existing state-of-art trackers, overcoming the problems generated by the challenging situations such as obvious appearance change, variant illumination, partial/full target occlusion, blur motion, rapid pose variation and onboard mechanical vibration, among others. To our best knowledge, this is the first work to present this framework for solving the online learning and tracking freewill 2D/3D target problems, and applied it in the UAVs. [less ▲]

Detailed reference viewed: 117 (15 UL)
Full Text
Peer Reviewed
See detailAutonomous Guided Car Using a Fuzzy Controller
Olivares Mendez, Miguel Angel UL; Campoy, Pascual; Mellado-Bataller, Ignacio et al

in Sen Gupta, Gourab; Bailey, Donald; Demidenko, Serge (Eds.) et al Recent Advances in Robotics and Automation (2013)

The goal of the work described in this paper is to develop a visual line guided system for being used on-board an Autonomous Guided Vehicle (AGV) commercial car, controlling the steering and using just ... [more ▼]

The goal of the work described in this paper is to develop a visual line guided system for being used on-board an Autonomous Guided Vehicle (AGV) commercial car, controlling the steering and using just the visual information of a line painted below the car. In order to implement the control of the vehicle, a Fuzzy Logic controller has been implemented, that has to be robust against curvature changes and velocity changes. The only input information for the controller is the visual distance from the image center captured by a camera pointing downwards to the guiding line on the road, at a commercial frequency of 30Hz. The good performance of the controller has successfully been demonstrated in a real environment at urban velocities. The presented results demonstrate the capability of the Fuzzy controller to follow a circuit in urban environments without previous information about the path or any other information from additional sensors. [less ▲]

Detailed reference viewed: 261 (3 UL)
Full Text
Peer Reviewed
See detailQuadcopter see and avoid using a fuzzy controller
Olivares Mendez, Miguel Angel UL; Mejias, Luis; Campoy, Pascual et al

in Uncertainty modeling in knowlege engineering and decision making : proceedings of the 10th International FLINS Conference (2012)

Unmanned Aerial Vehicles (UAVs) industry is a fast growing sector. Nowadays, the market offers numerous possibilities for off-the-shelf UAVs such as quadrotors or fixed-wings. Until UAVs demonstrate ... [more ▼]

Unmanned Aerial Vehicles (UAVs) industry is a fast growing sector. Nowadays, the market offers numerous possibilities for off-the-shelf UAVs such as quadrotors or fixed-wings. Until UAVs demonstrate advance capabilities such as autonomous collision avoidance they will be segregated and restricted to flight in controlled environments. This work presents a visual fuzzy servoing system for obstacle avoidance using UAVs. To accomplish this task we used the visual information from the front camera. Images are processed off-board and the result send to the Fuzzy Logic controller which then send commands to modify the orientation of the aircraft. Results from flight test are presented with a commercial off-the-shelf platform. [less ▲]

Detailed reference viewed: 99 (0 UL)
Full Text
Peer Reviewed
See detailA Hierarchical Strategy for Real-Time Tracking On-Board UAVs
Martinez, Carol; Campoy, Pascual; Mondragon, Ivan F. et al

in ICUAS 2012 : 2012 International Conference on Unmanned Aircraft Systems (2012, June)

In this paper, we present a real-time tracking strategy based on direct methods for tracking tasks on-board UAVs, that is able to overcome problems posed by the challenging conditions of the task: e.g ... [more ▼]

In this paper, we present a real-time tracking strategy based on direct methods for tracking tasks on-board UAVs, that is able to overcome problems posed by the challenging conditions of the task: e.g. constant vibrations, fast 3D changes, and limited capacity on-board. The vast majority of approaches make use of feature-based methods to track objects. Nonetheless, in this paper we show that although some of these feature-based solutions are faster, direct methods can be more robust under fast 3D motions (fast changes in position), some changes in appearance, constant vibrations (without requiring any specific hardware or software for video stabilization), and situations where part of the object to track is out the field of view of the camera. The performance of the proposed strategy is evaluated with images from real-flight tests using different evaluation mechanisms (e.g. accurate position estimation using a Vicon sytem). Results show that our tracking strategy performs better than well known feature-based algorithms and well known configurations of direct methods, and that the recovered data is robust enough for vision-in-the-loop tasks. [less ▲]

Detailed reference viewed: 39 (1 UL)
Full Text
Peer Reviewed
See detailSee-and-Avoid Quadcopter using Fuzzy Control Optimized by Cross-Entropy
Olivares Mendez, Miguel Angel UL; Campoy, Pascual; Mellado-Bataller, Ignacio et al

in See-and-Avoid Quadcopter using Fuzzy Control Optimized by Cross-Entropy (2012)

In this work we present an optimized fuzzy visual servoing system for obstacle avoidance using an unmanned aerial vehicle. The cross-entropy theory is used to optimise the gains of our controllers. The ... [more ▼]

In this work we present an optimized fuzzy visual servoing system for obstacle avoidance using an unmanned aerial vehicle. The cross-entropy theory is used to optimise the gains of our controllers. The optimization process was made using the ROS-Gazebo 3D simulation with purposeful extensions developed for our experiments. Visual servoing is achieved through an image processing front-end that uses the Camshift algorithm to detect and track objects in the scene. Experimental flight trials using a small quadrotor were performed to validate the parameters estimated from simulation. The integration of cross-entropy methods is a straightforward way to estimate optimal gains achieving excellent results when tested in real flights. [less ▲]

Detailed reference viewed: 81 (2 UL)
Full Text
Peer Reviewed
See detailRapid Prototyping Framework for Visual Control of Autonomous Micro Aerial Vehicles
Mellado-Bataller, Ignacio; Campoy, Pascual; Olivares Mendez, Miguel Angel UL et al

in Advances in Intelligent Systems and Computing (2012), 193

Rapid prototyping environments can speed up the research of visual control algorithms. We have designed and implemented a software framework for fast prototyping of visual control algorithms for Micro ... [more ▼]

Rapid prototyping environments can speed up the research of visual control algorithms. We have designed and implemented a software framework for fast prototyping of visual control algorithms for Micro Aerial Vehicles (MAV). We have applied a combination of a proxy-based network communication architecture and a custom Application Programming Interface. This allows multiple experimental configurations, like drone swarms or distributed processing of a drones video stream. Currently, the framework supports a low-cost MAV: the Parrot AR.Drone. Real tests have been performed on this platform and the results show comparatively low figures of the extra communication delay introduced by the framework, while adding new functionalities and flexibility to the selected drone. This implementation is open-source and can be downloaded from www.vision4uav.com/?q=VC4MAV-FW [less ▲]

Detailed reference viewed: 69 (1 UL)
Full Text
Peer Reviewed
See detailUAS See-and-Avoid using two different approaches of Fuzzy Control
Olivares Mendez, Miguel Angel UL; Mejias, Luis; Campoy, Pascual et al

in 2012 International Conference on Unmanned Aircraft Systems (ICUAS'12) (2012)

This work presents two UAS See and Avoid approaches using Fuzzy Control. We compare the performance of each controller when a Cross-Entropy method is applied to optimase the parameters for one of the ... [more ▼]

This work presents two UAS See and Avoid approaches using Fuzzy Control. We compare the performance of each controller when a Cross-Entropy method is applied to optimase the parameters for one of the controllers. Each controller receive information from an image processing frontend that detect and track targets in the environment. Visual information is then used under a visual servoing approach to perform autonomous avoidance. Experimental flight trials using a small quadrotor were performed to validate and compare the behaviour of both controllers. [less ▲]

Detailed reference viewed: 47 (1 UL)
Full Text
Peer Reviewed
See detailAdaptive Control System based on Lineal Control Theory for the Path-Following Problem of a Car-Like Mobile Robot
Sanchez-Lopez, Jose Luis; Campoy, Pascual; Olivares Mendez, Miguel Angel UL et al

in IFAC Conference on Advances in PID Control PID'12 (2012)

The objective of this paper is to design a path following control system for a car-like mobile robot using classical linear control techniques, so that it adapts on-line to varying conditions during the ... [more ▼]

The objective of this paper is to design a path following control system for a car-like mobile robot using classical linear control techniques, so that it adapts on-line to varying conditions during the trajectory following task. The main advantages of the proposed control structure is that well known linear control theory can be applied in calculating the PID controllers to ful l control requirements, while at the same time it is exible to be applied in non-linear changing conditions of the path following task. For this purpose the Frenet frame kinematic model of the robot is linearised at a varying working point that is calculated as a function of the actual velocity, the path curvature and kinematic parameters of the robot, yielding a transfer function that varies during the trajectory. The proposed controller is formed by a combination of an adaptive PID and a feed-forward controller, which varies accordingly with the working conditions and compensates the non-linearity of the system. The good features and exibility of the proposed control structure have been demonstrated through realistic simulations that include both kinematics and dynamics of the car-like robot. [less ▲]

Detailed reference viewed: 82 (1 UL)
Full Text
Peer Reviewed
See detailOn-board and Ground Visual Pose Estimation Techniques for UAV Control
Martinez, Carol; Mondragon, Ivan F.; Olivares Mendez, Miguel Angel UL et al

in JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS (2011), 61(1-4), 301-320

In this paper, two techniques to control UAVs (Unmanned Aerial Vehicles), based on visual information are presented. The first one is based on the detection and tracking of planar structures from an on ... [more ▼]

In this paper, two techniques to control UAVs (Unmanned Aerial Vehicles), based on visual information are presented. The first one is based on the detection and tracking of planar structures from an on-board camera, while the second one is based on the detection and 3D reconstruction of the position of the UAV based on an external camera system. Both strategies are tested with a VTOL (Vertical take-off and landing) UAV, and results show good behavior of the visual systems (precision in the estimation and frame rate) when estimating the helicopter's position and using the extracted information to control the UAV. [less ▲]

Detailed reference viewed: 138 (0 UL)
Full Text
Peer Reviewed
See detailA visual AGV-urban car using Fuzzy control
Olivares Mendez, Miguel Angel UL; Mellado, I.; Campoy, P. et al

in Automation, Robotics and Applications (ICARA), 2011 5th International Conference on (2011)

The goal of the work described in this paper is to develop a visual line guided system for being used on-board an Autonomous Guided Vehicle (AGV) commercial car, controlling the steering and using just ... [more ▼]

The goal of the work described in this paper is to develop a visual line guided system for being used on-board an Autonomous Guided Vehicle (AGV) commercial car, controlling the steering and using just the visual information of a line painted below the car. In order to implement the control of the vehicle, a Fuzzy Logic controller has been implemented, that has to be robust against curvature changes and velocity changes. The only input information for the controller is the visual distance from the image center captured by a camera pointing downwards to the guiding line on the road, at a commercial frequency of 30Hz. The good performance of the controller has successfully been demonstrated in a real environment at urban velocities. The presented results demonstrate the capability of the Fuzzy controller to follow a circuit in urban environments without previous information about the path or any other information from additional sensors. [less ▲]

Detailed reference viewed: 228 (1 UL)
Full Text
Peer Reviewed
See detail3D object following based on visual information for Unmanned Aerial Vehicles
Mondragón, I. F.; Campoy, P.; Olivares Mendez, Miguel Angel UL et al

in Robotics Symposium, 2011 IEEE IX Latin American and IEEE Colombian Conference on Automatic Control and Industry Applications (LARC) (2011)

Detailed reference viewed: 64 (1 UL)
Full Text
Peer Reviewed
See detailAerial object following using visual fuzzy servoing
Olivares Mendez, Miguel Angel UL; Mondragon, Ivan; Campoy, Pascual et al

in First Workshop on Research, Development and Education on Unmanned Aerial Systems (RED-UAS 2011) (2011)

This article presents a visual servoing system to follow a 3D moving object by a Micro Unmanned Aerial Vehicle (MUAV). The presented control strategy is based only on the visual information given by an ... [more ▼]

This article presents a visual servoing system to follow a 3D moving object by a Micro Unmanned Aerial Vehicle (MUAV). The presented control strategy is based only on the visual information given by an adaptive tracking method based on the color information. A visual fuzzy system has been developed for servoing the camera situated on a rotary wing MAUV, that also considers its own dynamics. This system is focused on continuously following of an aerial moving target object, maintaining it with a fixed safe distance and centered on the image plane. The algorithm is validated on real flights on outdoors scenarios, showing the robustness of the proposed systems against winds perturbations, illumination and weather changes among others. The obtained results indicate that the proposed algorithms is suitable for complex controls task, such object following and pursuit, flying in formation, as well as their use for indoor navigation [less ▲]

Detailed reference viewed: 51 (3 UL)
Full Text
Peer Reviewed
See detailNON-SYMMETRIC MEMBERSHIP FUNCTION FOR FUZZY-BASED VISUAL SERVOING ONBOARD A UAV
Olivares Mendez, Miguel Angel UL; Campoy, P.; Martinez, C. et al

in Ruan, D Li, TR Xu, Y Chen, GQ Kerre, EE (Ed.) COMPUTATIONAL INTELLIGENCE: FOUNDATIONS AND APPLICATIONS: PROCEEDINGS OF THE 9TH INTERNATIONAL FLINS CONFERENCE (2010, August)

This paper presents the definition of non-symmetric membership function for Fuzzy controllers applied to a pan & tilt vision platform onboard an Unmanned Aerial Vehicle. This improvement allows the ... [more ▼]

This paper presents the definition of non-symmetric membership function for Fuzzy controllers applied to a pan & tilt vision platform onboard an Unmanned Aerial Vehicle. This improvement allows the controllers to have a more adaptive behavior to the non-linearities presented in an UAV. This implementation allows the UAV to follow objects in the environment by using Lucas-Kanade visual tracker, in spite of the aircraft vibrations, the movements of the objects and the aircraft, update has been tested in real flights with an unmanned helicopter of the Computer Vision Group at the UPM, with very successful results, attaining a considerable reduction of the error during the tracking tests. [less ▲]

Detailed reference viewed: 56 (0 UL)