1,064 research outputs found
Computational intelligence approaches to robotics, automation, and control [Volume guest editors]
No abstract available
Correntropy: Answer to non-Gaussian noise in modern SLAM applications?
The problem of non-Gaussian noise/outliers has been intrinsic in modern Simultaneous Localization and Mapping (SLAM) applications. Despite numerous algorithms in SLAM, it has become crucial to address this problem in the realm of modern robotics applications. This work focuses on addressing the above-mentioned problem by incorporating the usage of correntropy in SLAM. Before correntropy, multiple attempts of dealing with non-Gaussian noise have been proposed with significant progress over time but the underlying assumption of Gaussianity might not be enough in real-life applications in robotics.Most of the modern SLAM algorithms propose the `best' estimates given a set of sensor measurements. Apart from addressing the non-Gaussian problems in a SLAM system, our work attempts to address the more complex part concerning SLAM: (a) If one of the sensors gives faulty measurements over time (`Faulty' measurements can be non-Gaussian in nature), how should a SLAM framework adapt to such scenarios? (b) In situations where there is a manual intervention or a 3rd party attacker tries to change the measurements and affect the overall estimate of the SLAM system, how can a SLAM system handle such situations?(addressing the Self Security aspect of SLAM). Given these serious situations how should a modern SLAM system handle the issue of the previously mentioned problems in (a) and (b)? We explore the idea of correntropy in addressing the above-mentioned problems in popular filtering-based approaches like Kalman Filters(KF) and Extended Kalman Filters(EKF), which highlights the `Localization' part in SLAM. Later on, we propose a framework of fusing the odometeries computed individually from a stereo sensor and Lidar sensor (Iterative Closest point Algorithm (ICP) based odometry). We describe the effectiveness of using correntropy in this framework, especially in situations where a 3rd party attacker attempts to corrupt the Lidar computed odometry. We extend the usage of correntropy in the `Mapping' part of the SLAM (Registration), which is the highlight of our work. Although registration is a well-established problem, earlier approaches to registration are very inefficient with large rotations and translation. In addition, when the 3D datasets used for alignment are corrupted with non-Gaussian noise (shot/impulse noise), prior state-of-the-art approaches fail. Our work has given birth to another variant of ICP, which we name as Correntropy Similarity Matrix ICP (CoSM-ICP), which is robust to large translation and rotations as well as to shot/impulse noise. We verify through results how well our variant of ICP outperforms the other variants under large rotations and translations as well as under large outliers/non-Gaussian noise. In addition, we deploy our CoSM algorithm in applications where we compute the extrinsic calibration of the Lidar-Stereo sensor as well as Lidar-Camera calibration using a planar checkerboard in a single frame. In general, through results, we verify how efficiently our approach of using correntropy can be used in tackling non-Gaussian noise/shot noise/impulse noise in robotics applications
A Robot Web for Distributed Many-Device Localisation
We show that a distributed network of robots or other devices which make
measurements of each other can collaborate to globally localise via efficient
ad-hoc peer to peer communication. Our Robot Web solution is based on Gaussian
Belief Propagation on the fundamental non-linear factor graph describing the
probabilistic structure of all of the observations robots make internally or of
each other, and is flexible for any type of robot, motion or sensor. We define
a simple and efficient communication protocol which can be implemented by the
publishing and reading of web pages or other asynchronous communication
technologies. We show in simulations with up to 1000 robots interacting in
arbitrary patterns that our solution convergently achieves global accuracy as
accurate as a centralised non-linear factor graph solver while operating with
high distributed efficiency of computation and communication. Via the use of
robust factors in GBP, our method is tolerant to a high percentage of faults in
sensor measurements or dropped communication packets.Comment: Published in IEEE Transactions on Robotics (TRO) 202
Reliable localization methods for intelligent vehicles based on environment perception
Mención Internacional en el título de doctorIn the near past, we would see autonomous vehicles and Intelligent Transport
Systems (ITS) as a potential future of transportation. Today, thanks to all the
technological advances in recent years, the feasibility of such systems is no longer a
question. Some of these autonomous driving technologies are already sharing our
roads, and even commercial vehicles are including more Advanced Driver-Assistance
Systems (ADAS) over the years. As a result, transportation is becoming more efficient
and the roads are considerably safer.
One of the fundamental pillars of an autonomous system is self-localization. An
accurate and reliable estimation of the vehicle’s pose in the world is essential to
navigation. Within the context of outdoor vehicles, the Global Navigation Satellite
System (GNSS) is the predominant localization system. However, these systems are
far from perfect, and their performance is degraded in environments with limited
satellite visibility. Additionally, their dependence on the environment can make them
unreliable if it were to change.
Accordingly, the goal of this thesis is to exploit the perception of the environment
to enhance localization systems in intelligent vehicles, with special attention to
their reliability. To this end, this thesis presents several contributions: First, a study
on exploiting 3D semantic information in LiDAR odometry is presented, providing
interesting insights regarding the contribution to the odometry output of each type
of element in the scene. The experimental results have been obtained using a public
dataset and validated on a real-world platform. Second, a method to estimate the
localization error using landmark detections is proposed, which is later on exploited
by a landmark placement optimization algorithm. This method, which has been
validated in a simulation environment, is able to determine a set of landmarks
so the localization error never exceeds a predefined limit. Finally, a cooperative
localization algorithm based on a Genetic Particle Filter is proposed to utilize vehicle
detections in order to enhance the estimation provided by GNSS systems. Multiple
experiments are carried out in different simulation environments to validate the
proposed method.En un pasado no muy lejano, los vehículos autónomos y los Sistemas Inteligentes
del Transporte (ITS) se veían como un futuro para el transporte con gran potencial.
Hoy, gracias a todos los avances tecnológicos de los últimos años, la viabilidad
de estos sistemas ha dejado de ser una incógnita. Algunas de estas tecnologías
de conducción autónoma ya están compartiendo nuestras carreteras, e incluso los
vehículos comerciales cada vez incluyen más Sistemas Avanzados de Asistencia a la
Conducción (ADAS) con el paso de los años. Como resultado, el transporte es cada
vez más eficiente y las carreteras son considerablemente más seguras.
Uno de los pilares fundamentales de un sistema autónomo es la autolocalización.
Una estimación precisa y fiable de la posición del vehículo en el mundo es esencial
para la navegación. En el contexto de los vehículos circulando en exteriores, el
Sistema Global de Navegación por Satélite (GNSS) es el sistema de localización predominante.
Sin embargo, estos sistemas están lejos de ser perfectos, y su rendimiento
se degrada en entornos donde la visibilidad de los satélites es limitada. Además, los
cambios en el entorno pueden provocar cambios en la estimación, lo que los hace
poco fiables en ciertas situaciones.
Por ello, el objetivo de esta tesis es utilizar la percepción del entorno para mejorar
los sistemas de localización en vehículos inteligentes, con una especial atención a
la fiabilidad de estos sistemas. Para ello, esta tesis presenta varias aportaciones:
En primer lugar, se presenta un estudio sobre cómo aprovechar la información
semántica 3D en la odometría LiDAR, generando una base de conocimiento sobre la
contribución de cada tipo de elemento del entorno a la salida de la odometría. Los
resultados experimentales se han obtenido utilizando una base de datos pública y se
han validado en una plataforma de conducción del mundo real. En segundo lugar,
se propone un método para estimar el error de localización utilizando detecciones
de puntos de referencia, que posteriormente es explotado por un algoritmo de
optimización de posicionamiento de puntos de referencia. Este método, que ha
sido validado en un entorno de simulación, es capaz de determinar un conjunto de
puntos de referencia para el cual el error de localización nunca supere un límite
previamente fijado. Por último, se propone un algoritmo de localización cooperativa
basado en un Filtro Genético de Partículas para utilizar las detecciones de vehículos
con el fin de mejorar la estimación proporcionada por los sistemas GNSS. El método
propuesto ha sido validado mediante múltiples experimentos en diferentes entornos
de simulación.Programa de Doctorado en Ingeniería Eléctrica, Electrónica y Automática por la Universidad Carlos III de MadridSecretario: Joshué Manuel Pérez Rastelli.- Secretario: Jorge Villagrá Serrano.- Vocal: Enrique David Martí Muño
Automated Static Camera Calibration with Intelligent Vehicles
Connected and cooperative driving requires precise calibration of the
roadside infrastructure for having a reliable perception system. To solve this
requirement in an automated manner, we present a robust extrinsic calibration
method for automated geo-referenced camera calibration. Our method requires a
calibration vehicle equipped with a combined GNSS/RTK receiver and an inertial
measurement unit (IMU) for self-localization. In order to remove any
requirements for the target's appearance and the local traffic conditions, we
propose a novel approach using hypothesis filtering. Our method does not
require any human interaction with the information recorded by both the
infrastructure and the vehicle. Furthermore, we do not limit road access for
other road users during calibration. We demonstrate the feasibility and
accuracy of our approach by evaluating our approach on synthetic datasets as
well as a real-world connected intersection, and deploying the calibration on
real infrastructure. Our source code is publicly available.Comment: 7 pages, 3 figures, accepted for presentation at the 34th IEEE
Intelligent Vehicles Symposium (IV 2023), June 4 - June 7, 2023, Anchorage,
Alaska, United States of Americ
Multi-Robot Relative Pose Estimation in SE(2) with Observability Analysis: A Comparison of Extended Kalman Filtering and Robust Pose Graph Optimization
In this study, we address multi-robot localization issues, with a specific
focus on cooperative localization and observability analysis of relative pose
estimation. Cooperative localization involves enhancing each robot's
information through a communication network and message passing. If odometry
data from a target robot can be transmitted to the ego robot, observability of
their relative pose estimation can be achieved through range-only or
bearing-only measurements, provided both robots have non-zero linear
velocities. In cases where odometry data from a target robot are not directly
transmitted but estimated by the ego robot, both range and bearing measurements
are necessary to ensure observability of relative pose estimation. For
ROS/Gazebo simulations, we explore four sensing and communication structures.
We compare extended Kalman filtering (EKF) and pose graph optimization (PGO)
estimation using different robust loss functions (filtering and smoothing with
varying batch sizes of sliding windows) in terms of estimation accuracy. In
hardware experiments, two Turtlebot3 equipped with UWB modules are used for
real-world inter-robot relative pose estimation, applying both EKF and PGO and
comparing their performance.Comment: 20 pages, 21 figure
- …