Leandro Fernandes

CaRINA Intelligent Robotic Car: Architectural design and applications

Abstract This paper presents the development of two outdoor intelligent vehicles platforms named CaRINA I and CaRINA II, their system architecture, simulation tools, and control modules. It also describes the development of the intelligent control system modules allowing the mobile robots and vehicles to navigate autonomously in controlled urban environments. Research work has been carried out on tele-operation, driver assistance systems, and autonomous navigation using the vehicles as platforms to experiments and validation. Our robotic platforms include mechanical adaptations and the development of an embedded software architecture. This paper addresses the design, sensing, decision making, and acting infrastructure and several experimental tests that have been carried out to evaluate both platforms and proposed algorithms. The main contributions of this work is the proposed architecture, that is modular and flexible, allowing it to be instantiated into different robotic platforms and applications. The communication and security aspects are also investigated.

Adaptive finite state machine based visual autonomous navigation system

In this paper we present an original approach applied to autonomous mobile robots navigation integrating localization and navigation using a topological map based on the proposed AFSM (adaptive finite state machine) technique. In this approach, the environment is mapped as a graph, and each possible path is represented by a sequence of states controlled by a FSM-finite state machine. An ANN (artificial neural network) is trained to recognize patterns on input data, where each pattern is associated to specific environment features or properties, consequently representing the present context/state of the FSM. When a new input pattern is recognized by the ANN (changing the current context), this allows the FSM to change to the next state and its associated action/behavior. The input features are related to specific local properties of the environment (obtained from sensors data), as for example, straight path, right and left turns, and intersections. This way, the FSM is integrated to a previously trained ANN, which acts as a key component recognizing and indicating the present state and the state changes, allowing the AFSM to select the current/correct action (local reactive behaviors) for each situation. The AFSM allows the mobile robot to autonomously follow a sequence of states/behaviors in order to reach a destination, first choosing an adequate local reactive behavior for each current state, and second detecting the changes in the current context/state, following a sequence of states/actions that codes the topological (global) path into the FSM (sequence of states/actions). The ANN is also a very important component of this system, since it can be trained/adapted to recognize a complex set of situations and state changes. In order to demonstrate the robustness of the proposed approach to different situations and sensors configurations, we evaluated the proposed approach for both indoor and outdoor environments, using a Pioneer P3-AT robot equipped with Kinect sensor for indoor environments, and an automated vehicle equipped with a standard RGB camera for urban roads environments. The proposed method was tested in different situations with success and demonstrated to be a promising approach to autonomous mobile robots control and navigation.

Path recognition for outdoor navigation using artificial neural networks: Case study

Navigation is a broad topic that has been receiving considerable attention from the mobile robotic community. In order to execute a safe navigation on outdoors it is necessary to identify parts of the terrain that can be traversed by the robot and parts that should be avoided. This paper describes an analyses of an image-based terrain identification based on different visual information using a multi-layer perceptron neural network. Experimental tests using an outdoor robot and a video camera have been conducted in real scenarios to evaluate the proposed methods.

Intelligent Robotic Car for Autonomous Navigation: Platform and System Architecture

This paper presents the platform and system architecture of an intelligent vehicle, presenting the control system modules allowing the vehicle to navigate autonomously. Our research group has been developed works on autonomous navigation and driver assistance systems, using CaRINA I platform to experiments and validation. Our platform includes mechanical vehicle adaptations and the development of an embedded software architecture, and its practical implementation. This paper addresses in details the sensing and acting infrastructure. Several experimental tests have been carried out to evaluate both platform and proposed algorithms.

A driving assistance system for navigation in urban environments

Mobile robot navigation in urban environments is a very complex task. As no single sensor is capable to deal with these situations by itself, sensor fusion techniques are required to allow safe navigation in this type of environment. This paper proposes an approach to combine different sensors in order to assist a driver in a cooperative manner. An adaptive attention zone in front of the vehicle is defined and the driver is notified about obstacles presence, identifying dangerous situations. Experiments using a commercial vehicle loaded with GPS and a LIDAR sensor have been performed in real environments in order to evaluate proposed approach.

Synthetisches amorphes SiO2 (SAS) für die keramische Industrie

KurzfassungSiliziumdoxid (SiO2) zählt zu den wichtigsten Eingangsmaterialien für die Lebensmittel- und Pharmaindustrie, Polymer-Verbundwerkstoffe sowie für die Tintenherstellung. In keramischen Werkstoffen werden feinkörnige Siliziumdioxidpartikel häufig als Pack- und Sinterhilfsmittel sowie zur Herstellung anderer Rohstoffe wie Mullit (3Al2O3·2SiO2) und Siliziumcarbid (SiC) eingesetzt. Da natürliches Siliziumdioxid einen relativ geringen Reinheitsgrad und inhomogene Eigenschaften aufweist, ist der Einsatz von synthetischem Siliziumdioxid in Feuerfestanwendungen und in der technischen Keramik notwendig. Diese Anwendungen erfordern eine verbesserte Kontrolle der Zusammensetzung und Mikrostruktur. Die Arbeit beschreibt einen systematischen Vergleich von synthetischem amorphem Siliziumdioxid (SAS) in vier verschiedenen Materialqualitäten. Die untersuchten SAS-Materialien wurden anhand verschiedener Verfahren formuliert (Natriumsilikat-Ausscheidungsprozess, SiCl4-Pyrolyse, Gewinnung aus Reishülsen und physikalische Abscheidung von gasförmigem Silizium). Unterschiede in der physikalisch-chemischen, thermischen und mikrostrukturellen Analyse jedes Stoffes stehen in Zusammenhang mit den jeweiligen Verfahrensweisen und Techniken des Herstellungsverfahrens. Die Arbeit bestätigte, dass die Synthesebedingungen einen bedeutenden Einfluss auf die Zusammensetzung und physikalischen Eigenschaften der getesteten SAS-Proben haben.AbstractSilica (SiO2) is one of the most important inputs for the food, pharmaceutics, polymer composite, and ink manufacturing industries. In ceramic materials, fine silica particles are widely used as a packing and sintering aid and to produce other raw materials like mullite (3Al2O3·2SiO2) and silicon carbide (SiC). As most of the silica sources found in nature have relatively low purity and nonhomogeneous properties, use of synthetic grades of silica is necessary in applications such as refractories and technical ceramics that require better control of product composition and microstructure. This paper describes a systematic comparison of four grades of synthetic amorphous silica (SAS) used in technical ceramics. The evaluated SAS materials were formulated by different methods (sodium silicate precipitation, SiCl4 pyrolysis, extraction from rice husks, and physical deposition of silicon vapour). Differences in the physico-chemical and thermal and microstructural characterization of each material are related to the principles and techniques involved in their manufacture. The study verified that synthesis conditions strongly influenced the composition and physical properties of the tested SAS samples.

Characterization of Synthetic Amorphous Silica (SAS) Used in the Ceramics Industry

Silica (SiO2) is one of the most important inputs for the food, pharmaceutics, polymer composite, and ink manufacturing industries. In ceramic materials, fine silica particles are widely used as a packing and sintering aid and to produce other raw materials like mullite (3Al2O3·2SiO2) and silicon carbide (SiC). As most of the silica sources found in nature have relatively low purity and nonhomogeneous properties, use of synthetic grades of silica is necessary in applications such as refractories and technical ceramics that require better control of product composition and microstructure. This paper describes a systematic comparison of four grades of synthetic amorphous silica (SAS) used in technical ceramics. The evaluated SAS materials were formulated by different methods (sodium silicate precipitation, SiCl4 pyrolysis, extraction from rice husks, and physical deposition of silicon vapour). Differences in the physicochemical and thermal and microstructural characterization of each material are related to the principles and techniques involved in their manufacture. The study verified that synthesis conditions strongly influenced the composition and physical properties of the tested SAS samples.