Overlapping guaranteed cost control for uncertain continuous-time delayed systems

Overlapping guaranteed cost control design problem is solved for a class of linear continuous-time uncertain systems with state as well as control delays. Unknown arbitrarily time-varying uncertainties with known bounds are considered. A point delay is supposed. Conditions preserving closed-loop systems expansion-contraction relations including the identical bounds of performance indices are proved. A linear matrix inequality (LMI) delay independent procedure is used for control design in the expanded space. The results are specialized on the overlapping decentralized control design. A numerical illustrative example is supplied.Peer ReviewedPostprint (published version

Controllability-observability of expanded composite systems

The relation between original and expanded systems within the Inclusion Principle from the point of view of controllability–observability of both subsystems and composite systems is studied. It is proved that complementary matrices always exist ensuring that the subsystems and the overall expanded system are simultaneously controllable–observable. Two practically important large classes of complementary matrices are identified to offer results computationally attractive. First, the existence of complementary matrices ensuring controllability–observability of decoupled subsystems is proved. Then, using this result, the same property is proved for the composite expanded system.Peer ReviewedPostprint (published version

Control activo de estructuras con aislamiento de base

En este artículo se propone un sistema de control activo como protección antisismica suplementaria para edificios con aislamiento de base y se analiza su viabilidad de forma numérica. Se considera una única fuerza de control actuando al nivel de la planta inferior. El algoritmo de control se basa en la estrategia de control predictivo, formulada para tener en cuenta el problema del tiempo de retardo en los actuadores. Los resultados obtenidos muestran que es posible lograr una reducción de las aceleraciones absolutas notablemente superior a la que se alcanza con el efecto pasivo del sistema de aislamiento de base. Ello puede ser útil en edificios que alberguen equipos especialmente sensibles.Peer Reviewe

Sistemas de control de estructuras de edificación por cables activos

En este artículo se propone un sistema de control activo de estructuras de edificación sometidas a excitaciones dinámicas (sísinicas o del viento) en el que los mecanismos actuadores son cables activos. La originalidad de la propuesta radica en la forma de instalar los cables activos en la estructura de los edificios objeto de control. La efectividad del sistema de control para reducir las oscilaciones horizontales de edificios con un coste razonable de energía es analizada mediante ensayos numéricos sobre dos edificios de 23 plantas cuyas estructuras son representativas de las tipologías estructurales más comúnmente utilizadas en edificios de esa altura. Se analiza exhaustivamente la robustez del sistema de control simulando numéricamente experiencias de control en situaciones límite. El análisis de los resultados obtenidos permite concluir que los cables activos son útiles para constituir sistemas de coiitrol de edificios de altura inedia, especialmente si su comportamiento dinámico horizontal es más similar al de una viga que al de un pórtico por existir pantallas verticales de rigidización.In tliis paper a control systein by active tendons is proposed and its effectiveness to reduce tlie dynaiiiic response of building structures with a reasonable cost of &ergy is tested by means of numerical experiments considering two 23-story buildings (called Bl and B2) subjected to seisinic and wind excitations. Bl is a franie building while Ba is a shear wall building. The dynamic behaviours of buildings Bl and Bg are representative of those of the different types of structures inost coimmonly used in buildings of about this nuinber of floors. The results of the numerical experiments allow to conclude that active cables are useful to constitute a feasible. reliable and iobust control system of mediun-high buildings and that tbey are more effectivé in buildiiigs with a dynainic beliaviour similar to tlie one of building B2.Peer Reviewe

New offset-free method for model predictive control of open channels

Irrigation or drainage canals can be controlled by model predictive control (MPC). Applying MPC with an internal model in the presence of unknown disturbances in some cases can lead to steady state offset. Therefore an additional component should be implemented along with the MPC. A new method eliminating the offset has been developed in this paper for MPC. It is based on combining two basic approaches of MPC. It has been implemented to control water levels in the three-pool UPC laboratory canal and further numerically tested using a test case benchmark proposed by the American Society of Civil Engineers (ASCE). It has been found that the developed offset-free method is able to eliminate the steady-state offset, while taking into account known and unknown disturbances.Peer ReviewedPostprint (author's final draft

Sistemas de control de estructuras de edificación por cables activos

En este artículo se propone un sistema de control activo de estructuras de edificación sometidas a excitaciones dinámicas (sísinicas o del viento) en el que los mecanismos actuadores son cables activos. La originalidad de la propuesta radica en la forma de instalar los cables activos en la estructura de los edificios objeto de control. La efectividad del sistema de control para reducir las oscilaciones horizontales de edificios con un coste razonable de energía es analizada mediante ensayos numéricos sobre dos edificios de 23 plantas cuyas estructuras son representativas de las tipologías estructurales más comúnmente utilizadas en edificios de esa altura. Se analiza exhaustivamente la robustez del sistema de control simulando numéricamente experiencias de control en situaciones límite. El análisis de los resultados obtenidos permite concluir que los cables activos son útiles para constituir sistemas de coiitrol de edificios de altura inedia, especialmente si su comportamiento dinámico horizontal es más similar al de una viga que al de un pórtico por existir pantallas verticales de rigidización.In tliis paper a control systein by active tendons is proposed and its effectiveness to reduce tlie dynaiiiic response of building structures with a reasonable cost of &ergy is tested by means of numerical experiments considering two 23-story buildings (called Bl and B2) subjected to seisinic and wind excitations. Bl is a franie building while Ba is a shear wall building. The dynamic behaviours of buildings Bl and Bg are representative of those of the different types of structures inost coimmonly used in buildings of about this nuinber of floors. The results of the numerical experiments allow to conclude that active cables are useful to constitute a feasible. reliable and iobust control system of mediun-high buildings and that tbey are more effectivé in buildiiigs with a dynainic beliaviour similar to tlie one of building B2.Peer Reviewe

A design procedure for overlapped guaranteed cost controllers

© 2008 the authors. This work has been accepted to IFAC for publication under a Creative Commons Licence CC-BY-NC-NDIn this paper a quadratic guaranteed cost control problem for a class of linear continuous-time state-delay systems with norm-bounded uncertainties is considered. We will suppose that the systems are composed by two overlapped subsystems but the results can be easily extended to any number of subsystems. The main objective is to design overlapping guaranteed cost controllers with tridiagonal gain matrices for these kind of systems by using a linear matrix inequality (LMI) approach. With this idea in mind, we present a design strategy to reduce the computational burden and to increase the feasibility in the LMI problem. In this context, the use of so-called complementary matrices play an important role. A simple example to illustrate the advantages achieved by using the proposed method is supplied.Peer ReviewedPostprint (published version

Control digital predictivo de la respuesta sísmica de estructuras

En este artículo se desarrolla un controlador digital predictivo con aplicación en la reducción de la respuesta sísmica de estructuras. Su eficacia se comprueba controlando la respuesta de un modelo de reactor nuclear.Peer Reviewe

Hysteresis-based design of dynamic reference trajectories to avoid saturation in controlled wind turbines

The main objective of this paper is to design a dynamic reference trajectory based on hysteresis to avoid saturation in controlled wind turbines. Basically, the torque controller and pitch controller set-points are hysteretically manipulated to avoid saturation and drive the system with smooth dynamic changes. Simulation results obtained from a 5MW wind turbine benchmark model show that our proposed strategy has a clear added value with respect to the baseline controller (a well-known and accepted industrial wind turbine controller). Moreover, the proposed strategy has been tested in healthy conditions but also in the presence of a realistic fault where the baseline controller caused saturation to nally conduct to instability.Peer ReviewedPostprint (author's final draft

Damage detection using robust PCA

Postprint (published version