97 research outputs found

    Robot localization in symmetric environment

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    The robot localization problem is a key problem in making truly autonomous robots. If a robot does not know where it is, it can be difficult to determine what to do next. Monte Carlo Localization as a well known localization algorithm represents a robot\u27s belief by a set of weighted samples. This set of samples approximates the posterior probability of where the robot is located. Our method presents an extension to the MCL algorithm when localizing in highly symmetrical environments; a situation where MCL is often unable to correctly track equally probable poses for the robot. The sample sets in MCL often become impoverished when samples are generated in several locations. Our approach incorporates the idea of clustering the samples and organizes them considering to their orientation. Experimental results show our method is able to successfully determine the position of the robot in symmetric environment, while ordinary MCL often fails

    Mobile robot localization under stochastic communication protocol

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    summary:In this paper, the mobile robot localization problem is investigated under the stochastic communication protocol (SCP). In the mobile robot localization system, the measurement data including the distance and the azimuth are received by multiple sensors equipped on the robot. In order to relieve the network burden caused by network congestion, the SCP is introduced to schedule the transmission of the measurement data received by multiple sensors. The aim of this paper is to find a solution to the robot localization problem by designing a time-varying filter for the mobile robot such that the filtering error dynamics satisfies the HH_{\infty} performance requirement over a finite horizon. First, a Markov chain is introduced to model the transmission of measurement data. Then, by utilizing the stochastic analysis technique and completing square approach, the gain matrices of the desired filter are designed in term of a solution to two coupled backward recursive Riccati equations. Finally, the effectiveness of the proposed filter design scheme is shown in an experimental platform

    Probabilistic constraint reasoning with Monte Carlo integration to robot localization

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    This work studies the combination of safe and probabilistic reasoning through the hybridization of Monte Carlo integration techniques with continuous constraint programming. In continuous constraint programming there are variables ranging over continuous domains (represented as intervals) together with constraints over them (relations between variables) and the goal is to find values for those variables that satisfy all the constraints (consistent scenarios). Constraint programming “branch-and-prune” algorithms produce safe enclosures of all consistent scenarios. Special proposed algorithms for probabilistic constraint reasoning compute the probability of sets of consistent scenarios which imply the calculation of an integral over these sets (quadrature). In this work we propose to extend the “branch-and-prune” algorithms with Monte Carlo integration techniques to compute such probabilities. This approach can be useful in robotics for localization problems. Traditional approaches are based on probabilistic techniques that search the most likely scenario, which may not satisfy the model constraints. We show how to apply our approach in order to cope with this problem and provide functionality in real time

    A flexible and dynamic mobile robot localization approach

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    [EN] The main goal of this paper is to provide an approach to solve the problem of localization in mobile robots using multi-agent systems. Usually, the robot localization problem is solved in static environments by the addition of the needed sensors in order to help the robot, but this is not useful in dynamic environments where the robot is moving through different rooms or areas. The novelty of this dynamic scenario is that each room is composed of external devices that can enter or exit the system in a dynamic way and report the position where the robot is. In this way, we propose a multi-agent system using the SPADE multi-agent technology platform to improve the location of mobile robots in dynamic scenarios. To do this, we are going to use some of the advantages offered by the SPADE platform such as presence notification and subscription protocols in order to design a friendship network between sensors/devices and the mobile robots.This work was supported by the project TIN2015-65515-C4-1-R of the Spanish government.Peñaranda-Cebrián, C.; Palanca Cámara, J.; Julian Inglada, VJ.; Botti, V. (2018). A flexible and dynamic mobile robot localization approach. Logic Journal of IGPL. https://doi.org/10.1093/jigpal/jzy045

    Planar Visibility: Testing and Counting

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    In this paper we consider query versions of visibility testing and visibility counting. Let SS be a set of nn disjoint line segments in R2\R^2 and let ss be an element of SS. Visibility testing is to preprocess SS so that we can quickly determine if ss is visible from a query point qq. Visibility counting involves preprocessing SS so that one can quickly estimate the number of segments in SS visible from a query point qq. We present several data structures for the two query problems. The structures build upon a result by O'Rourke and Suri (1984) who showed that the subset, VS(s)V_S(s), of R2\R^2 that is weakly visible from a segment ss can be represented as the union of a set, CS(s)C_S(s), of O(n2)O(n^2) triangles, even though the complexity of VS(s)V_S(s) can be Ω(n4)\Omega(n^4). We define a variant of their covering, give efficient output-sensitive algorithms for computing it, and prove additional properties needed to obtain approximation bounds. Some of our bounds rely on a new combinatorial result that relates the number of segments of SS visible from a point pp to the number of triangles in sSCS(s)\bigcup_{s\in S} C_S(s) that contain pp.Comment: 22 page

    Ultra-wideband time of flight based localization system and odometry fusion for a scanning 3 DoF magnetic field autonomous robot

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    Solving the robot localization problem is one of the most necessary requirements for autonomous robots. Several methodologies can be used to determine its location as accurately as possible. What makes this difficult is the existence of uncertainty in the sensing of the robot. The uncertain information needs to be combined in an optimal way. This paper stresses a Kalman filter to combine information from the odometry and Ultra Wide Band Time of Flight distance modules, which lacks the orientation. The proposed system validated in a real developed platform performs the fusion task which outputs position and orientation of the robot. It is used to localize the robot and make a 3 DoF scanning of magnetic field in a room. Other examples can be pointed out with the same localization techniques in service and industrial autonomous robots.Project “TEC4Growth - Pervasive Intelligence, Enhancers and Proofs of Concept with Industrial Impact/NORTE-01-0145-FEDER-000020” is financed by the North Portugal Regional Operational. Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF). This work is also financed by the ERDF European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme, and by National Funds through the FCT Funda¸cao para a Ciˆencia e a Tecnologia (Portuguese Foundation for Science and Technology) within project POCI-01-0145-FEDER-006961.info:eu-repo/semantics/publishedVersio

    Autonomous robot navigation for automotive assembly task: an industry use-case

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    Automobile industry faces one of the most flexible productivity caused by the number of customized models variants due to the buyers needs. This fact requires the production system to introduce flexible, adaptable and cooperative with humans solutions. In the present work, a panel that should be mounted inside a van is addressed. For that purpose, a mobile manipulator is suggested that could share the same space with workers helping each other. This paper presents the navigation system for the robot that enters the van from the rear door after a ramp, operates and exits. The localization system is based on 3DOF methodologies that allow the robot to operate autonomously. Real tests scenarios prove the precision and repeatability of the navigation system outside, inside and during the ramp access of the van.This work is financed by the ERDF- European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation- COMPETE 2020 Programme, and by National Funds through the Portuguese funding agency, FCT- Fundação para a Ciência ea Tecnologia, within project SAICTPAC/0034/2015 - POCI-01- 0145-FEDER-016418.info:eu-repo/semantics/publishedVersio
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