Robust adaptive regulation without persistent excitation

A globally convergent adaptive regulator for minimum or nonminimum phase systems subject to bounded distrubances and unmodeled dynamics is presented. The control strategy is designed for a particular input-output representation obtained from the state space representation of the system. The leading coefficient of the new representation is the product of the observability and controllability matrices of the system. The controller scheme uses a Least Squares identification algorithm with a dead zone. The dead zone is chosen to obtain convergence properties on the estimates and on the covariance matrix as well. This allows the definition of modified estimates which secure well-conditioned matrices in the adaptive control law. Explicit bounds on the plant output are given

Reverse pumping: theory and experimental validation on a multi-kites system

International audienceMost kite wind power systems have a great drawback that wind turbines do not have: they cannot stay in the air if the wind is not strong enough, [7-16]. As a consequence, most of the kite systems need to land when there is no wind, and to take-off once the wind is strong enough. These maneuvers are quite risky because generally the wind gets weak and turbulent close to the ground's surface. Moreover, as the wind can be strong enough at high altitude and weak close to the ground, it might lead to losses in energy production. From a material point of view, "classic" landings and takeoffs need a landing zone, ground handling or infrastructure (such as pylons) that reduces the advantages of kite systems. Some ideas, such as embedded motors or helium balloons, might solve this problem, but they have their own drawbacks such as the weight of the motor and its battery, the necessity of a conductive cable or the need to refill the balloons. The following paper studies a solution called "reverse pumping". It basically consists of providing kinetic energy to the kite by pulling the kite with a rope. This kinetic energy is then transformed into potential energy by gaining altitude. This technique allows to keep the kite airborne in total absence of wind. This paper will study the reverse pumping principle, the constrains on the aerodynamical model, flight simulations and will present the experimental setup used to validate the theoretical study

Energy production control of an experimental kite system in presence of wind gusts

International audienceThe growing need of energy, global warming and recent nuclear power plant accidents have shown that renewable energies need to be developed for tomorrow's world. Wind energy is generally harvested using wind turbines. Unfortunately, these systems have some drawbacks such as their cost, and the amount of steel and concrete used for construction. As their size grows, their complexity increases exponentially. This paper studies an alternative solution for the production of wind energy, using a kite's traction force. The aim of this paper is to control the amount of energy produced by the kite, and to be able to fly it safely in the presence of strong wind gusts. Our theoretical work has been implemented in a scale model flying autonomously in a wind tunnel. The proposed control strategy has led to control the system output power with an accuracy greater than 95%, with unknown wind speeds varying from 7.5 to 9 m/s

perspectives from Mexico and South Korea

Thesis(Master) --KDI School:Master of Public Policy,2019The main finding of this study is that developmental states still hold opportunities and capacity for the promotion of economic development, even if current circumstances present a more reduced or different policy space than what their dirigisme or authoritarian counterparts in the late 19th and 20th centuries faced. This study presents the compared cases of Mexico and Korea (South Korea or Republic of Korea) as two newly industrialized countries that have developed their automotive sector with very similar, developmental state-led, industrial policies. In both countries, outcomes had different degrees of success depending on the circumstances and constraints for policymaking and implementation existing in each society. The main argument is that although these political and institutional circumstances, unique to each state and society, can constrain policy options and shape their outcomes, they can also create new policy opportunities, which are frequently overlooked. Understanding and leveraging these lessons towards developmental efforts of today’s developing nation-states is more relevant than ever. With the new trends and directions that are already visible in the automotive industry, it is very important that governments and societies have clarity of what elements made past successes possible, to learn from them and iterate through their own constraints towards the construction of their own unique experiences of economic success.Introduction Developmental states and their role in industrialization and economic growth The Mexican auto industry The Korean Auto Industry Trends and disruptive innovation in the automotive industry ReferencesmasterpublishedCarlos Rogelio LOZANO MARTINEZ

Fault Estimation and Control for a Quad-Rotor MAV Using a Polynomial Observer. Part I: Fault Detection

International audienceThis work addresses the problem of fault detection and diagnosis (FDD) for a quad-rotor mini aerial vehicle (MAV). Actuator faults are considered on this paper. The basic idea behind the proposed method is to estimate the faults signals using the extended state observers theory. To estimate the faults, a polynomial observer is presented by using the available measurements and know inputs of the system. In order to investigate the observability and diagnosability properties of the system, a differential algebra approach is proposed. Furthermore, an evaluation function depending on the system states is developed, in order to be used in a controller, which will compensate the failures. The effectiveness of the methodology is illustrated by means of numerical simulations and some experimental tests

Modeling and Control of mini UAV

International audienc

Fault Estimation for a Quad-Rotor MAV Using a Polynomial Observer

International audienceThis work addresses the problem of fault detection and diagnosis (FDD) for a quad-rotor mini air vehicle (MAV). Actuator faults are considered on this paper. The basic idea behind the proposed method is to estimate the faults signals using the extended state observers theory. To estimate the faults, a polynomial observer (Aguilar et al. 2011; Mata-Machuca et al., Commun Nonlinear Sci Numer Simul 15(12):4114-4130, 2010, BioSystems 100(1):65-69, 2010) is presented by using the available measurements and know inputs of the system. In order to investigate the diagnosability properties of the system, a differential algebra approach is proposed (Cruz-Victoria et al., J Frankl Inst 345(2):102-118, 2008; and Martinez-Guerra and Diop, IEE P-Contr Theor Ap 151(1):130-135, 2004). The effectiveness of the methodology is illustrated by means of numerical simulations

Four Tilting Rotor Convertible MAV: Modeling and Real-Time Hover Flight Control

International audienceThis paper describes the modeling, control and hardware implementation of an experimental tilt-rotor aircraft. This vehicle combines the high-speed cruise capabilities of a conventional airplane with the hovering capabilities of a helicopter by tilting their four rotors. Changing between cruise and hover flight modes in mid-air is referred to transition. Dynamic model of the vehicle is derived both for vertical and horizontal flight modes using Newtonian approach. Two nonlinear control strategies are presented and evaluated at simulation level to control, the vertical and horizontal flight dynamics of the vehicle in the longitudinal plane. An experimental prototype named Quad-plane was developed to perform the vertical flight. A low-cost DSP-based Embedded Flight Control System (EFCS) was designed and built to achieve autonomous attitude-stabilized flight

Global stabilisation of the PVTOL aircraft with lateral force coupling and bounded inputs

"This work is devoted to prove that the nonlinear control scheme previously proposed by Zavala-Río, Fantoni and Lozano for the global stabilisation of the planar vertical take-off and landing (PVTOL) aircraft with bounded inputs neglecting the lateral force coupling is robust with respect to the parameter characterising such a lateral force coupling, ϵ, as long as such a parameter takes small enough values. In other words, global stabilisation is achieved even if ϵ > 0, provided that such a parameter be sufficiently small. As far as the authors are aware, such a property has not been proved in other existing control schemes when the value of ϵ is not known. The presented methodology is based on the use of embedded saturation functions. Furthermore, experimental results of the control algorithm implemented on a real prototype are presented.

Investigación de las causas que llevan a la liquidación de las empresas en la localidad de chapinero, de la ciudad de Bogotá D.C., con el fin de desarrollar una herramienta que permita contrarrestar este fenómeno

Estudio llevado a cabo en la localidad de Chapinero de la cuidad de Bogotá D.C.. En el cual se determinaron algunas de las causas más frecuentes que llevan a la toma de decisiones de cierre y liquidación de las pequeñas y medianas empresas Esta investigación de trabajo de grado ha hecho un análisis a partir de la información obtenida de evaluaciones adelantadas por la Cámara de Comercio de Bogotá a Superintendencia de Sociedades y trabajo de campo realizado en la localidad.Administrador (a) de EmpresasPregrad