References of "Journal of Intelligent & Robotic Systems"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailMonocular Visual-Inertial SLAM-Based Collision Avoidance Strategy for Fail-Safe UAV Using Fuzzy Logic Controllers
Fu, Changhong; Olivares Mendez, Miguel Angel UL; Suarez-Fernandez, Ramon et al

in Journal of Intelligent & Robotic Systems (2014), 73(1-4), 513-533

Detailed reference viewed: 240 (17 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: 164 (9 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: 210 (9 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: 173 (1 UL)
Full Text
Peer Reviewed
See detailVisual 3-D SLAM from UAVs
Artieda, Jorge; Sebastian, Jose M.; Campoy, Pascual et al

in JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS (2009), 55(4-5), 299-321

The aim of the paper is to present, test and discuss the implementation of Visual SLAM techniques to images taken from Unmanned Aerial Vehicles (UAVs) outdoors, in partially structured environments. Every ... [more ▼]

The aim of the paper is to present, test and discuss the implementation of Visual SLAM techniques to images taken from Unmanned Aerial Vehicles (UAVs) outdoors, in partially structured environments. Every issue of the whole process is discussed in order to obtain more accurate localization and mapping from UAVs flights. Firstly, the issues related to the visual features of objects in the scene, their distance to the UAV, and the related image acquisition system and their calibration are evaluated for improving the whole process. Other important, considered issues are related to the image processing techniques, such as interest point detection, the matching procedure and the scaling factor. The whole system has been tested using the COLIBRI mini UAV in partially structured environments. The results that have been obtained for localization, tested against the GPS information of the flights, show that Visual SLAM delivers reliable localization and mapping that makes it suitable for some outdoors applications when flying UAVs. [less ▲]

Detailed reference viewed: 74 (7 UL)
Full Text
Peer Reviewed
See detailComputer Vision Onboard UAVs for Civilian Tasks
Campoy, Pascual; Correa, Juan F.; Mondragon, Ivan et al

in JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS (2009), 54(1-3), 105-135

Computer vision is much more than a technique to sense and recover environmental information from an UAV. It should play a main role regarding UAVs' functionality because of the big amount of information ... [more ▼]

Computer vision is much more than a technique to sense and recover environmental information from an UAV. It should play a main role regarding UAVs' functionality because of the big amount of information that can be extracted, its possible uses and applications, and its natural connection to human driven tasks, taking into account that vision is our main interface to world understanding. Our current research's focus lays on the development of techniques that allow UAVs to maneuver in spaces using visual information as their main input source. This task involves the creation of techniques that allow an UAV to maneuver towards features of interest whenever a GPS signal is not reliable or sufficient, e. g. when signal dropouts occur (which usually happens in urban areas, when flying through terrestrial urban canyons or when operating on remote planetary bodies), or when tracking or inspecting visual targets-including moving ones-without knowing their exact UMT coordinates. This paper also investigates visual servoing control techniques that use velocity and position of suitable image features to compute the references for flight control. This paper aims to give a global view of the main aspects related to the research field of computer vision for UAVs, clustered in four main active research lines: visual servoing and control, stereo-based visual navigation, image processing algorithms for detection and tracking, and visual SLAM. Finally, the results of applying these techniques in several applications are presented and discussed: this study will encompass power line inspection, mobile target tracking, stereo distance estimation, mapping and positioning. [less ▲]

Detailed reference viewed: 133 (2 UL)
Peer Reviewed
See detailAn Experiment for Truly Parallel Logic Programming
Efthivoulidis, G.; Vlassis, Nikos UL; Tsanakas, P. et al

in Journal of Intelligent & Robotic Systems (1996), 16(2), 169-184

Detailed reference viewed: 90 (0 UL)