314 research outputs found
Timed trajectory generation combined with an Extended Kalman Filter for a vision-based autonomous mobile robot
Series : Advances in intelligent systems and computing, vol. 193, ISSN 2194-5357Planning collision-free trajectories requires the combination of generation and modulation techniques. This is especially important if temporal stabilization of the generated trajectories is considered. Temporal stabilization means to conform to the planned movement time, in spite of environmental conditions or perturbations. This timing problem has not been addressed in most current robotic systems, and it is critical in several robotic tasks such as sequentially structured actions or human-robot interaction. This work focuses on generating trajectories for a mobile robot, whose goal is to reach a target within a constant time, independently of the world complexity. Trajectories are generated by nonlinear dynamical systems. Herein, we extend our previous work by including an Extended Kalman Filter (EKF) to estimate the target location relative to the robot. A simulated hospital environment and a Pioneer 3-AT robot are used to demonstrate the robustness and reliability of the proposed approach in cluttered, dynamic and uncontrolled scenarios. Multiple experiments confirm that the inclusion of the EKF preserves the timing properties of the overall architecture.Work supported by the Portuguese Science Foundation (grant PTDC/EEA-CRO/100655/2008), and by project FCT PEst-OE/EEI/LA0009/2011. Jorge B. Silva is supported by PhD Grant SFRH/BD/68805/2010, granted by the Portuguese Science Foundation
Generating timed trajectories foran autonomous robot
Tese de Doutoramento Programa Doutoral em Engenharia ElectrĂłnica e ComputadoresThe inclusion of timed movements in control architectures for mobile navigation has
received an increasing attention over the last years. Timed movements allow modulat-
ing the behavior of the mobile robot according to the elapsed time, such that the robot
reaches a goal location within a specified time constraint. If the robot takes longer
than expected to reach the goal location, its linear velocity is increased for compen-
sating the delay. Timed movements are also relevant when sequences of missions are
considered. The robot should follow the predefined time schedule, so that the next
mission is initiated without delay. The performance of the architecture that controls
the robot can be validated through simulations and field experiments. However, ex-
perimental tests do not cover all the possible solutions. These should be guided by a
stability analysis, which might provide directions to improve the architecture design
in cases of inadequate performance of the architecture.
This thesis aims at developing a navigation architecture and its stability analysis
based on the Contraction Theory. The architecture is based on nonlinear dynamical
systems and must guide a mobile robot, such that it reaches a goal location within a
time constraint while avoiding unexpected obstacles in a cluttered and dynamic real
environment. The stability analysis based on the Contraction Theory might provide
conditions to the dynamical systems parameters, such that the dynamical systems are
designed as contracting, ensuring the global exponential stability of the architecture.
Furthermore, Contraction Theory provides solutions to analyze the success of the mis-
sion as a stability problem. This provides formal results that evaluate the performance
of the architecture, allowing the comparison to other navigation architectures.
To verify the ability of the architecture to guide the mobile robot, several experi-
mental tests were conducted. The obtained results show that the proposed architecture
is able to drive mobile robots with timed movements in indoor environments for large
distances without human intervention. Furthermore, the results show that the Con-
traction Theory is an important tool to design stable control architectures and to
analyze the success of the robotic missions as a stability problem.A inclusão de movimentos temporizados em arquitecturas de controlo para navegação
mĂłvel tem aumentado ao longo dos Ăşltimos anos. Movimentos temporizados permitem
modular o comportamento do robĂ´ de tal forma que ele chegue ao seu destino dentro de
um tempo especificado. Se o robĂ´ se atrasar, a sua velocidade linear deve ser aumen-
tada para compensar o atraso. Estes movimentos são também importantes quando se
consideram sequências de missões. O robô deve seguir o escalonamento da sequência,
de tal forma que a prĂłxima missĂŁo seja iniciada sem atraso. O desempenho da arqui-
tectura pode ser validado através de simulações e experiências reais. Contudo, testes
experimentais nĂŁo cobrem todas as possĂveis soluções. Estes devem ser conduzidos por
uma análise de estabilidade, que pode fornecer direcções para melhorar o desempenho
da arquitectura.
O objectivo desta tese é desenvolver uma arquitectura de navegação e analisar a sua
estabilidade através da teoria da Contracção. A arquitectura é baseada em sistemas
dinâmicos não lineares e deve controlar o robô móvel num ambiente real, desordenado
e dinâmico, de tal modo que ele chegue à posição alvo dentro de uma restrição de
tempo especificada. A análise de estabilidade baseada na teoria da Contracção pode
fornecer condições aos parâmetros dos sistemas dinâmicos de modo a desenha-los como
contracções, e assim garantir a estabilidade exponencial global da arquitectura. Esta
teoria fornece ainda soluções interessantes para analisar o sucesso da missão como um
problema de estabilidade. Isto providencia resultados formais que avaliam o desem-
penho da arquitectura e permitem a comparação com outras arquitecturas.
Para verificar a habilidade da arquitectura em controlar o robĂ´ mĂłvel, foram con-
duzidos vários testes experimentais. Os resultados obtidos mostram que a arquitectura
proposta Ă© capaz de controlar robĂ´s mĂłveis com movimentos temporizados em ambi-
entes interiores durante grandes distâncias e sem intervenção humana. Além disso,
os resultados mostram que a teoria da Contracção é uma ferramenta importante para
desenhar arquitecturas de controlo estáveis e para analisar o sucesso das missões efec-
tuadas pelo robĂ´ como um problema de estabilidade.Portuguese Science and Technology Foundation (FCT) SFRH/BD/68805/2010
A Real Application of an Autonomous Industrial Mobile Manipulator within Industrial Context
In modern industry there are still a large number of low added-value processes that can be automated or semi-automated with safe cooperation between robot and human operators. The European SHERLOCK project aims to integrate an autonomous industrial mobile manipulator (AIMM) to perform cooperative tasks between a robot and a human. To be able to do this, AIMMs need to have a variety of advanced cognitive skills like autonomous navigation, smart perception and task management. In this paper, we report the project’s tackle in a paradigmatic industrial application combining accurate autonomous navigation with deep learning-based 3D perception for pose estimation to locate and manipulate different industrial objects in an unstructured environment. The proposed method presents a combination of different technologies fused in an AIMM that achieve the proposed objective with a success rate of 83.33% in tests carried out in a real environment.This research was funded by EC research project “SHERLOCK—Seamless and safe human-centered robotic applications for novel collaborative workplace”. Grant number: 820683 (https://www.sherlock-project.eu accessed on 12 March 2021)
10081 Abstracts Collection -- Cognitive Robotics
From 21.02. to 26.02.2010, the Dagstuhl Seminar 10081 ``Cognitive Robotics \u27\u27 was held in Schloss Dagstuhl~--~Leibniz Center for Informatics.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
ViT-A*: Legged Robot Path Planning using Vision Transformer A*
Legged robots, particularly quadrupeds, offer
promising navigation capabilities, especially in scenarios requiring traversal over diverse terrains and obstacle avoidance.
This paper addresses the challenge of enabling legged robots
to navigate complex environments effectively through the integration of data-driven path-planning methods. We propose
an approach that utilizes differentiable planners, allowing the
learning of end-to-end global plans via a neural network for
commanding quadruped robots. The approach leverages 2D
maps and obstacle specifications as inputs to generate a global
path. To enhance the functionality of the developed neural
network-based path planner, we use Vision Transformers (ViT)
for map pre-processing, to enable the effective handling of
larger maps. Experimental evaluations on two real robotic
quadrupeds (Boston Dynamics Spot and Unitree Go1) demonstrate the effectiveness and versatility of the proposed approach
in generating reliable path plans
- …