Semi-online neural-Q_leaming for real-time robot learning

Reinforcement learning (RL) is a very suitable technique for robot learning, as it can learn in unknown environments and in real-time computation. The main difficulties in adapting classic RL algorithms to robotic systems are the generalization problem and the correct observation of the Markovian state. This paper attempts to solve the generalization problem by proposing the semi-online neural-Q_learning algorithm (SONQL). The algorithm uses the classic Q_learning technique with two modifications. First, a neural network (NN) approximates the Q_function allowing the use of continuous states and actions. Second, a database of the most representative learning samples accelerates and stabilizes the convergence. The term semi-online is referred to the fact that the algorithm uses the current but also past learning samples. However, the algorithm is able to learn in real-time while the robot is interacting with the environment. The paper shows simulated results with the "mountain-car" benchmark and, also, real results with an underwater robot in a target following behavior

A system to evaluate the accuracy of a visual mosaicking methodology

When underwater vehicles navigate close to the ocean floor, computer vision techniques can be applied to obtain motion estimates. A complete system to create visual mosaics of the seabed is described in this paper. Unfortunately, the accuracy of the constructed mosaic is difficult to evaluate. The use of a laboratory setup to obtain an accurate error measurement is proposed. The system consists on a robot arm carrying a downward looking camera. A pattern formed by a white background and a matrix of black dots uniformly distributed along the surveyed scene is used to find the exact image registration parameters. When the robot executes a trajectory (simulating the motion of a submersible), an image sequence is acquired by the camera. The estimated motion computed from the encoders of the robot is refined by detecting, to subpixel accuracy, the black dots of the image sequence, and computing the 2D projective transform which relates two consecutive images. The pattern is then substituted by a poster of the sea floor and the trajectory is executed again, acquiring the image sequence used to test the accuracy of the mosaicking system

PRIM an Open Mobile Robot Platform. Motivation, Present and Future Trends

This paper is focused on the robot mobile platform PRIM (platform robot information multimedia). This robot has been made in order to cover two main needs of our group, on one hand the need for a full open mobile robotic platform that is very useful in fulfilling the teaching and research activity of our school community, and on the other hand with the idea of introducing an ethical product which would be useful as mobile multimedia information point as a service tool. This paper introduces exactly how the system is made up and explains just what the philosophy is behind this work. The navigation strategies and sensor fusion, where machine vision system is the most important one, are oriented towards goal achievement and are the key to the behaviour of the robot

Plane-to-plane positioning from image-based visual servoing and structured light

In this paper we face the problem of positioning a camera attached to the end-effector of a robotic manipulator so that it gets parallel to a planar object. Such problem has been treated for a long time in visual servoing. Our approach is based on linking to the camera several laser pointers so that its configuration is aimed to produce a suitable set of visual features. The aim of using structured light is not only for easing the image processing and to allow low-textured objects to be treated, but also for producing a control scheme with nice properties like decoupling, stability, well conditioning and good camera trajectory

Studies about the atomic capabilities concept for linear control systems in physical multi-agent environments

This paper shows the impact of the atomic capabilities concept to include control-oriented knowledge of linear control systems in the decisions making structure of physical agents. These agents operate in a real environment managing physical objects (e.g. their physical bodies) in coordinated tasks. This approach is presented using an introspective reasoning approach and control theory based on the specific tasks of passing a ball and executing the offside manoeuvre between physical agents in the robotic soccer testbed. Experimental results and conclusions are presented, emphasising the advantages of our approach that improve the multi-agent performance in cooperative systems

Disseny i desenvolupament d'una plataforma robòtica educativa

La finalitat del projecte, com el nom indica, tracta de dissenyar i desenvolupar una plataforma robòtica educativa, que pugui ser controlada des d'un entorn amigable i accessible des del major nombre de situacions possible, evitant en la mesura del que sigui possible, dependre d'un sistema operatiu concret. Així mateix es busca desenvolupar un projecte que sigui fàcilment reproduïble amb el mínim cost econòmic.

Manipulator control board

The Mechatronics Research Centre (MRC) owns a small scale robot manipulator called aMini-Mover 5. This robot arm is a microprocessor-controlled, six-jointed mechanical armdesigned to provide an unusual combination of dexterity and low cost.The Mini-Mover-5 is operated by a number of stepper motors and is controlled by a PCparallel port via a discrete logic board. The manipulator also has an impoverished array ofsensors.This project requires that a new control board and suitable software be designed to allow themanipulator to be controlled from a PC. The control board will also provide a mechanism forthe values measured using some sensors to be returned to the PC.On this project I will consider: stepper motor control requirements, sensor technologies,power requirements, USB protocols, USB hardware and software development and controlrequirements (e.g. sample rates).In this report we will have a look at robots history and background, as well as we willconcentrate how stepper motors and parallel port work

Entorn de suport al diagnòstic d'estenosi de caròtida

L’objectiu d’aquest projecte és ampliar la plataforma Starviewer integrant els mòdulsnecessaris per donar suport al diagnòstic de l’estenosi de caròtida permetentinterpretar de forma més fàcil les imatges Angiografia per Ressonància Magnètica(ARM). La plataforma Starviewer és un entorn informàtic que integra funcionalitatsbàsiques i avançades pel processament i la visualització d’imatges mèdiques. Estàdesenvolupat pel Grup d’Informàtica Gràfica de la Universitat de Girona i l’Institut deDiagnòstic per la Imatge (IDI) de l’hospital Dr. Josep Trueta. Una de les limitacions de la plataforma és el no suportar el tractament de lesions delsistema vascular. Per això ens proposem a corregir-ho i ampliar les seves extensionsper a poder diagnosticar l’estenosi de caròtida