Teleoperated visual inspection and surveillance with unmanned ground and aerial vehicles,” Int

Abstract—This paper introduces our robotic system named UGAV (Unmanned Ground-Air Vehicle) consisting of two semi-autonomous robot platforms, an Unmanned Ground Vehicle (UGV) and an Unmanned Aerial Vehicles (UAV). The paper focuses on three topics of the inspection with the combined UGV and UAV: (A) teleoperated control by means of cell or smart phones with a new concept of automatic configuration of the smart phone based on a RKI-XML description of the vehicles control capabilities, (B) the camera and vision system with the focus to real time feature extraction e.g. for the tracking of the UAV and (C) the architecture and hardware of the UAV

Object detection in robotics using morphological information

Mestrado em Engenharia Electrónica e TelecomunicaçõesUma das componentes mais importantes em sistemas de processamento de imagem é a detecção de objectos de interesse. Contudo, a detecção de objectos é um desafio. Dada uma imagem arbitrária e assumindo que se está interessado em localizar um determinado objecto, o grande objectivo da detecção de objectos passa por determinar se existe ou não qualquer objecto de interesse. Esta tese encontra-se inserida no domínio do RoboCup e foca o desenvolvimento de algoritmos para a detecção de bolas oficiais da FIFA, um objecto importante no futebol robótico. Para atingir o objectivo principal, foram desenvolvidos três algoritmos para detectar bolas de futebol com cores arbitrárias, usando informação morfológica obtida através do detector de cortornos Canny e da tranformada de Hough. Em primeiro lugar, foi desenvolvida uma abordagem onde se implementou um algoritmo específico usando a transformada de Hough circular. Em segundo lugar, foi implementado um algoritmo que utiliza uma função da biblioteca OpenCV dedicada à procura de círculos em imagens. Finalmente, os dois primeiros algoritmos foram agrupados para criar uma nova abordagem, na qual ambos os algoritmos são usados. São apresentados resultados experimentais que mostram que os algoritmos desenvolvidos são precisos, sendo capazes de realizar a detecção da bola de forma confiável em situações de tempo-real. ABSTRACT: One of the most important steps in image processing systems is the detection of objects of interest. However, object detection is a challenging task. Given an arbitrary image and assuming that we are interested in locating a particular object, the goal of object detection is to determine whether or not there is any object of interest. This thesis is inserted in the RoboCup domain and is focused on the development of algorithms for the detection of arbitrary FIFA balls, an important object for soccer robots. To achieve the main objective, we developed three algorithms to detect arbitrary soccer balls using morphological information given by the Canny edge detector and the Hough Transform. First, it was developed an approach where we implemented a specific algorithm using the circular Hough Transform, applied after the segmentation of the acquired image. Secondly, it was implemented an algorithm that uses a function of the OpenCV library dedicated to the search of circles in images. Finally, the two first algorithms were joined to create a new approach in which both of the algorithms are used. Experimental results are presented, showing that the developed algorithms are accurate, being capable of reliable ball detection in real-time situations

Robust Object Detection at Regions of Interest with an Application in Ball Recognition

In this paper, we present a new combination of a biologically inspired attention system (VOCUS -- Visual Object detection with a CompUtational attention System) with a robust object detection method. As an application, we built a reliable system for ball recognition in the RoboCup context. Firstly, VOCUS finds regions of interest generating a hypothesis for possible locations of the ball. Secondly, a fast classifier verifies the hypothesis by detecting balls at regions of interest. The combination of both approaches makes the system highly robust and eliminates false detections. Furthermore, the system is quickly adaptable to balls in different scenarios: The complex classifier is universally applicable to balls in every context and the attention system improves the performance by learning scenario-specific features quickly from only a few training examples

Finding Objects of Interest in Images using Saliency and Superpixels

The ability to automatically find objects of interest in images is useful in the areas of compression, indexing and retrieval, re-targeting, and so on. There are two classes of such algorithms – those that find any object of interest with no prior knowledge, independent of the task, and those that find specific objects of interest known a priori. The former class of algorithms tries to detect objects in images that stand-out, i.e. are salient, by virtue of being different from the rest of the image and consequently capture our attention. The detection is generic in this case as there is no specific object we are trying to locate. The latter class of algorithms detects specific known objects of interest and often requires training using features extracted from known examples. In this thesis we address various aspects of finding objects of interest under the topics of saliency detection and object detection. We present two saliency detection algorithms that rely on the principle of center-surround contrast. These two algorithms are shown to be superior to several state-of-the-art techniques in terms of precision and recall measures with respect to a ground truth. They output full-resolution saliency maps, are simpler to implement, and are computationally more efficient than most existing algorithms. We further establish the relevance of our saliency detection algorithms by using them for the known applications of object segmentation and image re-targeting. We first present three different techniques for salient object segmentation using our saliency maps that are based on clustering, graph-cuts, and geodesic distance based labeling. We then demonstrate the use of our saliency maps for a popular technique of content-aware image resizing and compare the result with that of existing methods. Our saliency maps prove to be a much more effective replacement for conventional gradient maps for providing automatic content-awareness. Just as it is important to find regions of interest in images, it is also important to find interesting images within a large collection of images. We therefore extend the notion of saliency detection in images to image databases. We propose an algorithm for finding salient images in a database. Apart from finding such images we also present two novel techniques for creating visually appealing summaries in the form of collages and mosaics. Finally, we address the problem of finding specific known objects of interest in images. Specifically, we deal with the feature extraction step that is a pre-requisite for any technique in this domain. In this context, we first present a superpixel segmentation algorithm that outperforms previous algorithms in terms quantitative measures of under-segmentation error and boundary recall. Our superpixel segmentation algorithm also offers several other advantages over existing algorithms like compactness, uniform size, control on the number of superpixels, and computational efficiency. We prove the effectiveness of our superpixels by deploying them in existing algorithms, specifically, an object class detection technique and a graph based algorithm, and improving their performance. We also present the result of using our superpixels in a technique for detecting mitochondria in noisy medical images

Design and Experimental Evaluation of a Context-aware Social Gaze Control System for a Humanlike Robot

Nowadays, social robots are increasingly being developed for a variety of human-centered scenarios in which they interact with people. For this reason, they should possess the ability to perceive and interpret human non-verbal/verbal communicative cues, in a humanlike way. In addition, they should be able to autonomously identify the most important interactional target at the proper time by exploring the perceptual information, and exhibit a believable behavior accordingly. Employing a social robot with such capabilities has several positive outcomes for human society. This thesis presents a multilayer context-aware gaze control system that has been implemented as a part of a humanlike social robot. Using this system the robot is able to mimic the human perception, attention, and gaze behavior in a dynamic multiparty social interaction. The system enables the robot to direct appropriately its gaze at the right time to the environmental targets and humans who are interacting with each other and with the robot. For this reason, the attention mechanism of the gaze control system is based on features that have been proven to guide human attention: the verbal and non-verbal cues, proxemics, the effective field of view, the habituation effect, and the low-level visual features. The gaze control system uses skeleton tracking and speech recognition,facial expression recognition, and salience detection to implement the same features. As part of a pilot evaluation, the gaze behavior of 11 participants was collected with a professional eye-tracking device, while they were watching a video of two-person interactions. Analyzing the average gaze behavior of participants, the importance of human-relevant features in human attention triggering were determined. Based on this finding, the parameters of the gaze control system were tuned in order to imitate the human behavior in selecting features of environment. The comparison between the human gaze behavior and the gaze behavior of the developed system running on the same videos shows that the proposed approach is promising as it replicated human gaze behavior 89% of the time