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1

Vision based persistent localization of a humanoid robot for locomotion tasks

Martínez P. A., Castelán M., Arechavaleta G.

International Journal of Applied Mathematics and Computer Science

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2016

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Vol. 26, no. 3

669--682

EN

Typical monocular localization schemes involve a search for matches between reprojected 3D world points and 2D image features in order to estimate the absolute scale transformation between the camera and the world. Successfully calculating such transformation implies the existence of a good number of 3D points uniformly distributed as reprojected pixels around the image plane. This paper presents a method to control the march of a humanoid robot towards directions that are favorable for visual based localization. To this end, orthogonal diagonalization is performed on the covariance matrices of both sets of 3D world points and their 2D image reprojections. Experiments with the NAO humanoid platform show that our method provides persistence of localization, as the robot tends to walk towards directions that are desirable for successful localization. Additional tests demonstrate how the proposed approach can be incorporated into a control scheme that considers reaching a target position.

2

Semantyczna lokalizacja robota mobilnego

Siemiątkowska B., Harasymowicz-Boggio B.

Prace Naukowe Politechniki Warszawskiej. Elektronika

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2014

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z. 194, t. 1

317--326

PL

Celem pracy jest przedstawienie algorytmu lokalizacji sematycznej na podstawie danych pochodzących z dalmierza laserowego i sensora Kinect. Opisywane są następujące etapy algorytmu: pobranie informacji z układu sensorycznego (dalmerza laserowego i kamery Kinect), analiza kształtu obserowanego otoczenia przy wykorzystaniu danych z dalmierza laserowego, segmentacja chmury punktów, określenie zbioru obserowwanych obiektów, określenie zbioru hipotez i agregacja informacji za pomocą teorii Dempstera-Shafera oraz klasyfikacja rodzaju pomieszczenia, w którym znajduje się robot. Opisywana metoda została przetestowana w rzeczywistym otoczeniu budynku Wydziału Mechatroniki Politechniki Warszawskiej.

EN

The paper presents the method of semantic localization of a mobile robot. The robot is equipped with the Sick laser finder and Kinect sesnor. The simplest source of information about an environment is a scan obtained by range sensor. The polygonal approximation of an observed area is performed. The shape of the polygon allow us to distinguish corridors from other places using simple rule based system. During the next step rooms are classified based on objects which have been recognized. Each object votes for a set of classes of rooms. In a real environment we deal with uncertainty. Usually probabilistic theory is used to solve the problem but it is not capable of capturing subjective uncertainty. In our approach instead of classical bayesian method we propose to performed classification using Dempster-Shafer theory (DST), which can be regarded as a generalization of the Bayesian theory and is able to deal with subjective uncertainty. The experiment performed in real office environment prooved the efficiency of our approach.

3

An Encoded Infrared Sheet of Light Navigational Beacon System for Precise Localization of Indoor Mobile Robot Vehicles

Kurian J., Saseendran Pillai P. R.

Journal of Automation Mobile Robotics and Intelligent Systems

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2009

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Vol. 3, No. 2

34-41

EN

A new localization approach to increase the navigational capabilities and object manipulation of autonomous mobile robots, based on an encoded infrared sheet of light beacon system, which provides position errors smaller than 0.02m is presented in this paper. To achieve this minimal position error, a resolution enhancement technique has been developed by utilising an inbuilt odometric/optical flow sensor information. This system respects strong low cost constraints by using an innovative assembly for the digitally encoded infrared transmitter. For better guidance of mobile robot vehicles, an online traffic signalling capability is also incorporated. Other added features are its less computational complexity and online localization capability all these without any estimation uncertainty. The constructional details, experimental results and computational methodologies of the system are also described.

4

A realization of an FPGA sub system for reducing odometric localization errors in wheeled mobile robots

Kurian J., Saseendran P.

Journal of Automation Mobile Robotics and Intelligent Systems

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2009

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Vol. 3, No. 3

26-33

EN

This paper introduces a simple and efficient method and its implementation in an FPGA for reducing the odometric localization errors caused by over count readings of an optical encoder based odometric system in a mobile robot due to wheel-slippage and terrain irregularities. The detection and correction is based on redundant encoder measurements. The method suggested relies on the fact that the wheel slippage or terrain irregularities cause more count readings from the encoder than what corresponds to the actual distance travelled by the vehicle. The standard quadrature technique is used to obtain four counts in each encoder period. In this work a three-wheeled mobile robot vehicle with one driving-steering wheel and two-fixed rear wheels in-axis, fitted with incremental optical encoders is considered. The CORDIC algorithm has been used for the computation of sine and cosine terms in the update equations. The results presented demonstrate the effectiveness of the technique.

5

Scan matching based SLAM - dealing with dynamic obstacles

Krejsa J., Vechet S.

Modelling and Optimization of Physical Systems

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2008

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z. 7

59--62

EN

Localization and mapping is essential task in autonomous mobile robotics. There is a number of methods dealing with the task. The method called Potential-Based Scan Matching uses proximity sensor data and does not require the odometry readings for successful localization. The method is resistant towards the noise in proximity sensors. This paper is focused on testing the method in dynamically changing environment. Tests were performed for variable size of obstacles and speed of its motion.

6

Wizyjny system lokalizacji robota mobilnego wykorzystujący znaczniki LED

Kiełczewski M., Pazderski D.

Elektronika : konstrukcje, technologie, zastosowania

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2008

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Vol. 49, nr 6

259-262

PL

W pracy przedstawiono wizyjny układ lokalizacji robota mobilnego, pozwalający na określenie jego pozycji i orientacji w ruchu płaskim. Przedstawiono strukturę sytemu pomiarowego, metodę pomiaru i przeprowadzano analizę jej dokładności. Zaprezentowano wyniki badań eksperymentalnych ilustrujących efektywność systemu pomiarowego.

EN

This paper presents a measurement system for a mobile robot localization which calculates its position and orientation on the plane based on vision system and active markers. The structure of the system is illustrated, the method of measurement is given and its accuracy is discussed. In order to show effectiveness of the system localization and to verify measurement errors experimental results are presented.