Homography-based ground plane detection using a single on-board camera

This study presents a robust method for ground plane detection in vision-based systems with a non-stationary camera. The proposed method is based on the reliable estimation of the homography between ground planes in successive images. This homography is computed using a feature matching approach, which in contrast to classical approaches to on-board motion estimation does not require explicit ego-motion calculation. As opposed to it, a novel homography calculation method based on a linear estimation framework is presented. This framework provides predictions of the ground plane transformation matrix that are dynamically updated with new measurements. The method is specially suited for challenging environments, in particular traffic scenarios, in which the information is scarce and the homography computed from the images is usually inaccurate or erroneous. The proposed estimation framework is able to remove erroneous measurements and to correct those that are inaccurate, hence producing a reliable homography estimate at each instant. It is based on the evaluation of the difference between the predicted and the observed transformations, measured according to the spectral norm of the associated matrix of differences. Moreover, an example is provided on how to use the information extracted from ground plane estimation to achieve object detection and tracking. The method has been successfully demonstrated for the detection of moving vehicles in traffic environments

Calibration of Ultra-Wide Fisheye Lens Cameras by Eigenvalue Minimization

We present a new technique for calibrating ultra-wide fisheye lens cameras by imposing the constraint that collinear points be rectified to be collinear, parallel lines to be parallel, and orthogonal lines to be orthogonal. Exploiting the fact that line fitting reduces to an eigenvalue problem, we do a rigorous perturbation analysis to obtain a Levenberg-Marquardt procedure for the optimization. Doing experiments, we point out that spurious solutions exist if collinearity and parallelism alone are imposed. Our technique has many desirable properties. For example, no metric information is required about the reference pattern or the camera position, and separate stripe patterns can be displayed on a video screen to generate a virtual grid, eliminating the grid point extraction processing

A study of the outdoor environmental design of high -rise residential area (HRFRAs), China: application and investigation of the environmental- behaviour theories and research methods for landscape design

Designers often believe that environmental design improves quality of life. Preference as an index of motivation has influences on many aspects of people. Based on a study of the relationship between actual uses and preferred outdoor environments, this research aims to deepen our understanding of place via public input and to improve the design quality of the central community garden (CCG) of high -rise flat residential areas ( HRFRAs) in China.With a total of 902 respondents from six HRFRAs, the investigation was carried out in three major Chinese cities, Beijing, Shenzhen and Hangzhou, in September 2006. Analysis at a general level reveals the preferred environmental patterns and significant predictors of the respondents' actual use. The comparisons at the city level indicate the territorial differences and characteristics of each city, respectively.Analysis of the results indicated that a quiet, green environment in an informal design style was the preferred environment which would improve residents' frequency of use. Of the environmental elements, waterscape and evergreens were particularly important to users. Although both of them are important to people's actual use, the effect of the prospect indicator (perspective of the CCG looking from a resident's window) was relatively weaker than the indicator of affordances, such as exercise facilities and children's playgrounds, etc.On the other hand, the results of the study explain the gap which often occurs between landscape architects' intentions and the manner in which the elements of the design actually work, in users' opinion. Landscape designers of the HRFRAs in China need to reorder the emphasis of the design aspects and adjust the contents of the environment to satisfy users' social, functional and psychological needs

Talk2BEV: Language-enhanced Bird's-eye View Maps for Autonomous Driving

Talk2BEV is a large vision-language model (LVLM) interface for bird's-eye view (BEV) maps in autonomous driving contexts. While existing perception systems for autonomous driving scenarios have largely focused on a pre-defined (closed) set of object categories and driving scenarios, Talk2BEV blends recent advances in general-purpose language and vision models with BEV-structured map representations, eliminating the need for task-specific models. This enables a single system to cater to a variety of autonomous driving tasks encompassing visual and spatial reasoning, predicting the intents of traffic actors, and decision-making based on visual cues. We extensively evaluate Talk2BEV on a large number of scene understanding tasks that rely on both the ability to interpret free-form natural language queries, and in grounding these queries to the visual context embedded into the language-enhanced BEV map. To enable further research in LVLMs for autonomous driving scenarios, we develop and release Talk2BEV-Bench, a benchmark encompassing 1000 human-annotated BEV scenarios, with more than 20,000 questions and ground-truth responses from the NuScenes dataset.Comment: Project page at https://llmbev.github.io/talk2bev

Artificial Intelligence and Systems Theory: Applied to Cooperative Robots

This paper describes an approach to the design of a population of cooperative robots based on concepts borrowed from Systems Theory and Artificial Intelligence. The research has been developed under the SocRob project, carried out by the Intelligent Systems Laboratory at the Institute for Systems and Robotics - Instituto Superior Tecnico (ISR/IST) in Lisbon. The acronym of the project stands both for "Society of Robots" and "Soccer Robots", the case study where we are testing our population of robots. Designing soccer robots is a very challenging problem, where the robots must act not only to shoot a ball towards the goal, but also to detect and avoid static (walls, stopped robots) and dynamic (moving robots) obstacles. Furthermore, they must cooperate to defeat an opposing team. Our past and current research in soccer robotics includes cooperative sensor fusion for world modeling, object recognition and tracking, robot navigation, multi-robot distributed task planning and coordination, including cooperative reinforcement learning in cooperative and adversarial environments, and behavior-based architectures for real time task execution of cooperating robot teams

THE TRACES OF THE PAST: INFORMATIVE TOOLS FOR THE RECONSTRUCTION OF AURELIAN WALLS IN RIONE TESTACCIO

Abstract. Rome has a great cultural heritage, formed by the stratification of styles and political influences from different eras. The different eras and architectural styles that have defined the city in the two millennia of history, make each part unique in its kind. This succession of changes has by necessity led to the denial of some archaeologies that in past ages were pivotal points in the development of the ancient city. The research presented here is intended to analyze and reconstruct the archeology of the river stretch of the Aurelian Walls on the Lungotevere Testaccio partly disappeared from the architectural landscape of the city. The research was set in two main phases, the first based on the two-dimensional study of the lost fabric, focusing on the cartographic study and the digitization of them in the GIS environment. The second one still under development foresees the digitalization of the threedimensional elements detected and the insertion of these within the dedicated platforms.</p