Experimental Estimation of Slipping in the Supporting Point of a Biped Robot

When developing a gait cycle on a low-friction surface, a biped robot eventually tends to slip. In general, it is commonto overcome this problem by means of either slow movements or physical adaptations of the robot at the contact pointwith the walking surface in order to increase the frictional characteristics. In the case of slipping, several types ofsensors have been used to identify the relative displacement at the contact point of the supporting leg with the walkingsurface for control purposes. This work is focused on the experimental implementation of a low-cost force sensor as ameasurement system of the slipping phenomenon. It is shown how, supported on a suitable change of coordinates,the force measurement at the contact point is used to obtain the total displacement at the supporting point due to thelow-friction conditions. This is an important issue when an accurate Cartesian task is required

Prediction-Based Control for Nonlinear Systems with Input Delay

This work has two primary objectives. First, it presents a state prediction strategy for a class of nonlinear Lipschitz systems subject to constant time delay in the input signal. As a result of a suitable change of variable, the state predictor asymptotically provides the value of the state τ units of time ahead. Second, it proposes a solution to the stabilization and trajectory tracking problems for the considered class of systems using predicted states. The predictor-controller convergence is proved by considering a complete Lyapunov functional. The proposed predictor-based controller strategy is evaluated using numerical simulations

Discretización exacta de un robot móvil con retardo de transporte

An exact discrete time model of a mobile robot of the type (2,0) that includes the time-delay induced by a communication network between the sensors and actuators on the mobile robot and the remote control system is presented. Simulations results are provided to show the performance of the proposed exact discrete time model. The performance of obtained model is better compared to the approximate model because it does not need a sampling period sufficiently small.En este trabajo se presenta la obtención del modelo exacto en tiempo discreto de un robot móvil tipo (2,0), bajo la consideración de la existencia de retardos de transporte en la señal de control, producidos por la propagación de las señales entre los sensores y actuadores del robot y el control remoto. El modelo obtenido es evaluado mediante simulación, comparando su desempeño con un modelo discreto aproximado que incluye también retardos de transporte y con el modelo en tiempo continuo del mismo sistema

Phylodynamics of vampire bat-transmitted rabies in Argentina

Common vampire bat populations distributed from Mexico to Argentina are important rabies reservoir hosts in Latin America. The aim of this work was to analyse the population structure of the rabies virus (RABV) variants associated with vampire bats in the Americas and to study their phylodynamic pattern within Argentina. The phylogenetic analysis based on all available vampire bat-related N gene sequences showed both a geographical and a temporal structure. The two largest groups of RABV variants from Argentina were isolated from northwestern Argentina and from the central western zone of northeastern Argentina, corresponding to livestock areas with different climatic, topographic and biogeographical conditions, which determined their dissemination and evolutionary patterns. In addition, multiple introductions of the infection into Argentina, possibly from Brazil, were detected. The phylodynamic analysis suggests that RABV transmission dynamics is characterized by initial epizootic waves followed by local enzootic cycles with variable persistence. Anthropogenic interventions in the ecosystem should be assessed taking into account not only the environmental impact but also the potential risk of disease spreading through dissemination of current RABV lineages or the emergence of novel ones associated with vampire bats.Fil: Torres, Carolina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lema, C.. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud; ArgentinaFil: Gury Dohmen, F.. Instituto de Zoonosis “Dr. Luis Pasteur”; ArgentinaFil: Beltran, F.. Instituto de Zoonosis “Dr. Luis Pasteur”; ArgentinaFil: Novaro, L.. Ministerio de Agricultura, Ganadería, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria; ArgentinaFil: Russo, S.. Ministerio de Agricultura, Ganadería, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria; ArgentinaFil: Freire, M. C.. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud; ArgentinaFil: Velasco Villa, A.. Centers for Disease Control and Prevention; Estados UnidosFil: Mbayed, Viviana Andrea. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología. Cátedra de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cisterna , D. M.. Ministerio de Agricultura, Ganadería, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria; Argentin

Design of a hands-on course in networked control systems

This report presents a hands-on course in networked control systems (NCS) to be integrated in the education of embedded control systems engineers. The course activities have a strong practical component and most of them are ap- plied exercises to be implemented in a NCS setup. The report containts four parts: a) a report that describes the experimental setup, proposing several activities that can be shaped into a course program according to the needs and diverse background of the targeted audience, b) a tentative program ex- ample for master students, c) a user manual to help setting up the hardware and software from a Live CD, and d) a quick guide to start working with the programming environment.Preprin

The feasibility of canine rabies elimination in Africa: dispelling doubts with data

<p><b>Background:</b> Canine rabies causes many thousands of human deaths every year in Africa, and continues to increase throughout much of the continent.</p> <p><b>Methodology/Principal Findings:</b> This paper identifies four common reasons given for the lack of effective canine rabies control in Africa: (a) a low priority given for disease control as a result of lack of awareness of the rabies burden; (b) epidemiological constraints such as uncertainties about the required levels of vaccination coverage and the possibility of sustained cycles of infection in wildlife; (c) operational constraints including accessibility of dogs for vaccination and insufficient knowledge of dog population sizes for planning of vaccination campaigns; and (d) limited resources for implementation of rabies surveillance and control. We address each of these issues in turn, presenting data from field studies and modelling approaches used in Tanzania, including burden of disease evaluations, detailed epidemiological studies, operational data from vaccination campaigns in different demographic and ecological settings, and economic analyses of the cost-effectiveness of dog vaccination for human rabies prevention.</p> <p><b>Conclusions/Significance:</b> We conclude that there are no insurmountable problems to canine rabies control in most of Africa; that elimination of canine rabies is epidemiologically and practically feasible through mass vaccination of domestic dogs; and that domestic dog vaccination provides a cost-effective approach to the prevention and elimination of human rabies deaths.</p&gt