The cognitive approach to the development of autonomous vehicles takes inspiration from human reasoning, and, conversely to the computationalist approach, rejects formulating fixed mathematical models to describe each possible behavior of vehicles and objects around them. The computationalist approach indeed has a weakness: developers cannot examine and mathematically formulate all possible real-world situations that drivers may encounter. Cognitive approaches provide a solution to this problem, as they suggest that vehicles should continually learn through experience as humans do, which would allow them to progressively grasp rare and unexpected behaviors. This thesis mainly addresses the pivotal question of detecting when some unexpected behavior is occurring - referred to as anomaly detection - within a cognitive self-awareness framework. The adopted framework is characterized by several desirable characteristics, such as being Bayesian, hierarchical, multi-sensorial, data-driven, and interpretable. A set of modules for anomaly detection and localization of an agent are proposed. Dynamic Bayesian Networks are used, as they are interpretable probabilistic models allowing hierarchical representation of variables potentially coming from multiple sensors; moreover, the links between variables inside Dynamic Bayesian Networks can be learned from data. All methods in the thesis adopt a filter called the Markov Jump Particle Filter that can be described through a Dynamic Bayesian Network on a minimum of three levels. When elaborating image data, Variational Autoencoders are adopted to perform dimensionality reduction while maintaining a probabilistic representation; novel methods for joining Variational Autoencoders and Bayesian filters are proposed. This thesis focuses on the elaboration of vehicular video and odometry data. First, self-awareness anomaly detection approaches to separately handle video and odometry data are proposed; then, an approach fusing the two modalities is introduced; the capability to localize the vehicle is also added. The proposed methods are evaluated on real-world and simulated data from terrestrial and aerial vehicles.

Emergent self-awareness in multi-sensor physical agents

SLAVIC, GIULIA
2024-05-06

Abstract

The cognitive approach to the development of autonomous vehicles takes inspiration from human reasoning, and, conversely to the computationalist approach, rejects formulating fixed mathematical models to describe each possible behavior of vehicles and objects around them. The computationalist approach indeed has a weakness: developers cannot examine and mathematically formulate all possible real-world situations that drivers may encounter. Cognitive approaches provide a solution to this problem, as they suggest that vehicles should continually learn through experience as humans do, which would allow them to progressively grasp rare and unexpected behaviors. This thesis mainly addresses the pivotal question of detecting when some unexpected behavior is occurring - referred to as anomaly detection - within a cognitive self-awareness framework. The adopted framework is characterized by several desirable characteristics, such as being Bayesian, hierarchical, multi-sensorial, data-driven, and interpretable. A set of modules for anomaly detection and localization of an agent are proposed. Dynamic Bayesian Networks are used, as they are interpretable probabilistic models allowing hierarchical representation of variables potentially coming from multiple sensors; moreover, the links between variables inside Dynamic Bayesian Networks can be learned from data. All methods in the thesis adopt a filter called the Markov Jump Particle Filter that can be described through a Dynamic Bayesian Network on a minimum of three levels. When elaborating image data, Variational Autoencoders are adopted to perform dimensionality reduction while maintaining a probabilistic representation; novel methods for joining Variational Autoencoders and Bayesian filters are proposed. This thesis focuses on the elaboration of vehicular video and odometry data. First, self-awareness anomaly detection approaches to separately handle video and odometry data are proposed; then, an approach fusing the two modalities is introduced; the capability to localize the vehicle is also added. The proposed methods are evaluated on real-world and simulated data from terrestrial and aerial vehicles.
6-mag-2024
El enfoque cognitivo para el desarrollo de vehículos autónomos se inspira en el razonamiento humano y, a la inversa del enfoque computacional, rechaza la formulación de modelos matemáticos fijos para describir cada posible comportamiento de los vehículos y objetos alrededor de ellos. En efecto, el enfoque computacional tiene una debilidad: los desarrolladores no pueden examinar y formular matemáticamente todas las posibles situaciones del mundo real que los conductores podrían encontrar. Los enfoques cognitivos proporcionan una solución a este problema, ya que sugieren que los vehículos deberían aprender continuamente a través de la experiencia como hacen los humanos, lo que les permitiría reconocer progresivamente comportamientos raros e inesperados. Esta tesis trata principalmente la question fundamental de detectar cuándo está ocurriendo algún comportamiento inesperado - definida como detección de anomalías - dentro de un marco de autoconciencia cognitiva. El marco adoptado tiene características deseables, como ser bayesiano, jerárquico, multisensorial, basado en datos e interpretable. Se propone un conjunto de módulos para la detección de anomalías y localización de un agente. Se utilizan Redes Bayesianas Dinámicas, ya que son modelos probabilísticos interpretables que permiten una representación jerárquica de variables potencialmente provenientes de sensores múltiples; además, los vínculos entre variables dentro de las Redes Bayesianas Dinámicas se pueden aprender de los datos. Todos los métodos en la tesis adoptan un filtro llamado Filtro de Partículas de Salto de Markov, que puede describirse a través de una Red Bayesiana Dinámica con un mínimo de tres niveles. Los datos de imágenes se procesan usando un Autocodificadores Variacionales para realizar una reducción de dimensionalidad manteniendo una representación probabilística; se proponen métodos novedosos para unir Autocodificadores Variacionales y filtros Bayesianos. Esta tesis se enfoca en la elaboración de datos de vehículos de video y odometría. En primer lugar, se proponen enfoques de detección de anomalías para elaborar por separado datos de vídeo y odometría; luego se introduce un enfoque que fusiona las dos modalidades; también se añade la capacidad de localizar el vehículo. Los métodos propuestos se evalúan con datos del mundo real y simulados, tanto de vehículos terrestres como aéreos.
Variational Autoencoder; Dynamical Variational Autoencoder; Kalman Filter; Particle Filter; autonomous systems; anomaly detection; video anomaly detection; Dynamic Bayesian Networks; visual-based localization; explainability; interpretability; sensor fusion
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11567/1171995
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