Environmental maps generation using LIDAR - 3D perception system

Orientador: Pablo Siqueira MeirellesTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia MecânicaResumo: Este trabalho apresenta o estudo e desenvolvimento de um Sistema de Percepção baseado na utilização de sensores telemétricos tipo LIDAR. Uma plataforma de escaneamento a laser em três dimensões LMS-3D é construída a fim da navegação autônoma de robôs. A área navegável é obtida a partir de mapas telemétricos, caracterizados com algoritmos de grades de ocupação (GO) (em duas dimensões com a terceira colorida e 3D) e com o cálculo de gradientes vetoriais. Dois tipos de áreas navegáveis são caracterizadas: (i) área de navegação primária representada por uma área livre dentro da GO; e (ii) área de navegação continua representada pela soma das áreas continuas e gradientes classificados com um determinado limiar. Este limiar indica se uma área é passível de navegação considerando as características do robô. A proposta foi avaliada experimentalmente em ambiente real, contemplou a detecção de obstáculos e a identificação de descontinuidadesAbstract: This thesis was proposed to demonstrate the study and development of a Perception System based on the utilization of a LIDAR telemetric sensors. It was proposed to create a LMS-3D three dimension laser scanning platform, in an attempt to promote the Autonomous Robot Navigation. The scanned area was obtained based on telemetric maps, which was characterized with Occupancy Grid algorithms (OG) (in two dimensions with the third colored and 3D) and Vector Gradients calculation. Two different navigation areas were characterized: (i) primary area of navigation, that represents the free area inside a OG, and (ii) continuous navigation area, that represents the navigated area composed by the sum of continuous areas and the gradients classified by a determined threshold, which indicates the possible navigated area, based on the robot characteristics. The proposition of this thesis was evaluated in a real environment and was able to identify the obstacles detection and also the discontinuanceDoutoradoMecanica dos Sólidos e Projeto MecanicoDoutor em Engenharia Mecânic

Local path planning in image space for autonomous robot navigation in unstructured environments

Abstract—An approach to stereo based local path planning in unstructured environments is presented. The approach differs from previous stereo based and image based planning systems (e.g. top-down occupancy grid planners, autonomous highway driving algorithms, and view-sequenced route representation), in that it uses specialized cost functions to find paths through an occupancy grid representation of the world directly in the image plane and forgoes a projection of cost information from the image plane down onto a top-down 2D Cartesian cost map. We discuss three cost metrics for path selection in image space. We present a basic image based planning system, discuss its susceptibility to rotational and translational oscillation, and present and implement two extensions to the basic system that overcome these limitations—a cylindrical based image system and a hierarchical planning system. All three systems are implemented in an autonomous robot and are tested against a standard top-down 2D Cartesian planning system on three outdoor courses of varying difficulty. We find that the basic image based planning system fails under certain conditions; however, the cylindrical based system is well suited to the task of local path planning and for use as a high resolution local planning component of a hierarchical planning system