A Velocity Algorithm for the Implementation of Gain-scheduled Controllers

A new method is proposed to implement gain-scheduled controllers for nonlinear plants. Given a family of linear feedback controllers designed for linearizations of a nonlinear plant about constant operating points, a nonlinear gain-scheduled controller is derived that preserves the input-output properties of the linear closed loop systems locally, about each equilibrium point. The key procedures in the proposed method are to provide integral action at the inputs to the plant and differentiate some of the measured outputs before they are fed back to the scheduled controller. For a fairly general class of systems, the nonlinear gain-scheduled controllers are easy to obtain, and their structure is similar to that of the original linear controllers.Research Initiation Grant of the Naval Postgraduate SchoolNSF under Grant ECS-9096109AFOSR under Grant F49620-93-1-0246AR under Grant DAAH01-93-G-001

Environmental Monitoring using Autonomous Vehicles: A Survey of Recent Searching Techniques

Autonomous vehicles are becoming an essential tool in a wide range of environmental applications that include ambient data acquisition, remote sensing, and mapping of the spatial extent of pollutant spills. Among these applications, pollution source localization has drawn increasing interest due to its scientific and commercial interest and the emergence of a new breed of robotic vehicles capable of performing demanding tasks in harsh environments without human supervision. In this task, the aim is to find the location of a region that is the source of a given substance of interest (e.g. a chemical pollutant at sea or a gas leakage in air) using a group of cooperative autonomous vehicles. Motivated by fast paced advances in this challenging area, this paper surveys recent advances in searching techniques that are at the core of environmental monitoring strategies using autonomous vehicles

A design method for distributed luenberger observers

The paper addresses the problem of designing distributed observers for discrete linear time-invariant (LTI) systems with distributed sensor nodes subjected to bounded measurement noise. A solution is proposed in terms of a distributed LTI Luenberger observer, thus departing from common linear time-varying solutions rooted in consensus-based distributed estimation techniques, and dispensing with the need for the exchange of covariance matrices. It is shown, under the conditions of collective observability, strong connectivity of the sensor communication network, and invertibility of the state transition matrix, that the resulting observer yields ultimate boundedness of the estimation error. A design example is given where the asymptotic performance of the proposed observer is shown to be similar to that obtained using a time-varying distributed Kalman filtering approach

The Widely scalable Mobile Underwater Sonar Technology (WiMUST) H2020 project: first year status

The Widely scalable Mobile Underwater Sonar Technology (WiMUST) project aims at developing a system of cooperative Autonomous Underwater Vehicles (AUVs) for geotechnical surveying and geophysical exploration. The paper reports about the first year activities and it gives an overview of the main objectives and methods. Results relative to distributed sensor array, cooperative control, mission planning, communications and preliminary experiments are summarized

Widely scalable mobile underwater sonar technology: an overview of the H2020 WiMUST project

The Widely scalable Mobile Underwater Sonar Technology (WIMUST) project is an H2020 Research and Innovation Action funded by European Commission. The project aims at developing a system of cooperative autonomous underwater vehicles (AUVs) for geotechnical surveying and geophysical exploration. The paper describes the main objectives of the project, given an overview of the methodologies adopted to achieve them, and summarizes the work done in the first year of R&D work

Erica: Prevalence Of Metabolic Syndrome In Brazilian Adolescents

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)To determine the prevalence of metabolic syndrome and its components in Brazilian adolescents. METHODS: We evaluated 37,504 adolescents who were participants in the Study of Cardiovascular Risks in Adolescents (ERICA), a cross-sectional, school-based, national study. The adolescents, aged from 12 to 17 years, lived in cities with populations greater than 100,000 inhabitants. The sample was stratified and clustered into schools and classes. The criteria set out by the International Diabetes Federation were used to define metabolic syndrome. Prevalences of metabolic syndrome were estimated according to sex, age group, school type and nutritional status. RESULTS: Of the 37,504 adolescents who were evaluated: 50.2% were female; 54.3% were aged from 15 to 17 years, and 73.3% were from public schools. The prevalence of metabolic syndrome was 2.6% (95% CI 2.3-2.9), slightly higher in males and in those aged from 15 to 17 years in most macro-regions. The prevalence was the highest in residents from the South macro-region, in the younger female adolescents and in the older male adolescents. The prevalence was higher in public schools (2.8% [95% CI 2.4-3.2]), when compared with private schools (1.9% [95% CI 1.4-2.4]) and higher in obese adolescents when compared with nonobese ones. The most common combinations of components, referring to 3/4 of combinations, were: enlarged waist circumference (WC), low HDL-cholesterol (HDL-c) and high blood pressure; followed by enlarged WC, low HDL-c and high triglycerides; and enlarged WC, low HDL-c, high triglycerides and blood pressure. Low HDL was the second most frequent component, but the highest prevalence of metabolic syndrome (26.8%) was observed in the presence of high triglycerides. CONCLUSIONS: ERICA is the first Brazilian nation-wide study to present the prevalence of metabolic syndrome and describe the role of its components. Despite the prevalence of Metabolic Syndrome being low, the high prevalences of some components and participation of others in the syndrome composition shows the importance of early diagnosis of this changes, even if not grouped within the metabolic syndrome.501Department of Science and Technology of the Secretariat of Science, Technology and Strategic Inputs of the Ministry of Health (Decit/SCTIE/MS)Health Sectorial Fund (Fundo Setorial de Saude - CT-Saude) of the Ministry of Science, Technology and Innovation (MCTI)FINEP [01090421]CNPq [2010/565037-2]Research Incentive Fund of the Hospital de Clinicas de Porto Alegre - (Fundo de Incentivo a Pesquisa do Hospital de Clinicas de Porto Alegre - FIPE-HCPA) [405.009/2012-7]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

On the design of gain-scheduled trajectory tracking controllers

International Journal of Robust and Nonlinear Control, special issue on Gain-Scheduling, 2002, 12:797-839.The article of record as published may be found at http://dx.doi.org/10.1002/rnc.705A new methodology is proposed for the design of trajectory tracking controllers for autonomous vehicles. The design technique builds on gain scheduling control theory. An application is made to the design of a trajectory tracking controller for a prototype autonomous underwater vehicle (AUV). The effectiveness and advantages of the new control laws derived are illustrated in simulation using a full set of non-linear equations of motion of the vehicle. Copyright # 2002 John Wiley & Sons, Ltd