Distributed estimation techniques forcyber-physical systems

Nowadays, with the increasing use of wireless networks, embedded devices and agents with processing and sensing capabilities, the development of distributed estimation techniques has become vital to monitor important variables of the system that are not directly available. Numerous distributed estimation techniques have been proposed in the literature according to the model of the system, noises and disturbances. One of the main objectives of this thesis is to search all those works that deal with distributed estimation techniques applied to cyber-physical systems, system of systems and heterogeneous systems, through using systematic review methodology. Even though systematic reviews are not the common way to survey a topic in the control community, they provide a rigorous, robust and objective formula that should not be ignored. The presented systematic review incorporates and adapts the guidelines recommended in other disciplines to the field of automation and control and presents a brief description of the different phases that constitute a systematic review. Undertaking the systematic review many gaps were discovered: it deserves to be remarked that some estimators are not applied to cyber-physical systems, such as sliding mode observers or set-membership observers. Subsequently, one of these particular techniques was chosen, set-membership estimator, to develop new applications for cyber-physical systems. This introduces the other objectives of the thesis, i.e. to present two novel formulations of distributed set-membership estimators. Both estimators use a multi-hop decomposition, so the dynamics of the system is rewritten to present a cascaded implementation of the distributed set-membership observer, decoupling the influence of the non-observable modes to the observable ones. So each agent must find a different set for each sub-space, instead of a unique set for all the states. Two different approaches have been used to address the same problem, that is, to design a guaranteed distributed estimation method for linear full-coupled systems affected by bounded disturbances, to be implemented in a set of distributed agents that need to communicate and collaborate to achieve this goal

Identificación de las principales tipologías de nubes utilizando HOG

[Resumen] Este artículo aborda la clasificación automática de nubes a partir de imágenes tomadas desde el suelo mediante técnicas que utilizan histogramas de vectores gradiente. La identificación de nubes tiene una importancia creciente en la industria solar como medio para producir predicciones locales de nubosidad a muy corto plazo. En este contexto se presentan los histogramas de vectores gradiente para extracción de características útiles para la clasificación. Se discuten y exponen ciertas propiedades de este tipo de características que son posteriormente puestas a prueba en la clasificación de nubes. El clasificador empleado es una máquina de vectores soporte SVM. Se consideran en la clasificación las principales tipologías de nubes: cúmulos, cirros y estratos.https://doi.org/10.17979/spudc.978849749808

High Technology Readiness Level Techniques for Brushless Direct Current Motors Failures Detection: A Systematic Review

Many papers related to this topic can be found in the bibliography; however, just a modest percentage of the introduced techniques are developed to a Technology Readiness Level (TRL) sufficiently high to be implementable in industrial applications. This paper is focused precisely on the review of this specific topic. The investigation on the state of the art has been carried out as a systematic review, a very rigorous and reliable standardised scientific methodology, and tries to collect the articles which are closer to a possible implementation. This selection has been carefully done with the definition of a series of rules, drawn to represent the adequate level of readiness of fault detection techniques which the various articles propose.Unión Europea (7PM / 2007-2013) / ERC n. 78533

A distributed set-membership estimator for linear systems considering multi-hop subspace decomposition

In this paper, a distributed set-membership estimator for linear full-coupled systems affected by bounded disturbances is presented. The estimator uses a multi-hop staircase decomposition, capturing the locally unobservable subspaces in a cascaded fashion with the information incoming from other agents involved in the network. Each agent has to find different sets for each subspace, that are mathematically described by zonotopes. The observer gains that minimize the size of those sets, i.e. the estimation uncertainty, can be designed in independent distributed steps by means of simple algebraic equations. Simulations are given to compare the proposed solution with others in the field. An important benefit of the proposed structure is the reduction of the computational requirements with respect to existing solutions. © 2021 Elsevier Lt

Diseño LQ e implementación distribuída para la estimación de estado

[Resumen] Este artículo trata el problema de la estimación distribuida del estado de una planta por dos agentes. El objetivo de cada uno de los agentes es reconstruir el estado completo a partir de sus propias medidas y la información intercambiada con el otro. Para ello, se introduce una novedosa estructura de observador en la cual se divide el espacio de estados en la parte observable por el agente en cuestión y la parte no observable por él. El diseño de las ganancias del observador se lleva a cabo mediante la resolución de un problema LQ en el que el usuario puede variar dos parámetros escalares para lograr una observación adecuada. Se introduce dicho algoritmo para una red con dos agentes siendo su generalización para un número indeterminado de agentes un posible futuro trabajo.Agencia Estatal de Investigación; DPI-75294-CS-2-RAgencia Estatal de Investigación; TEC2016-80242-PMinisterio de Ciencia y Tecnología; DPI2013-44135-