Filtros de Kalman adaptativos para sistemas não-lineares

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2019.O filtro de Kalman é amplamente utilizado para estimar estados em propostas de controle. Entretanto, ele requer correto conhecimento das estatísticas de incertezas para o bom desempenho em implementações em sistemas reais. Deste modo, este trabalho apresenta nova proposta de adaptação em covariância de incertezas de processo aplicada em filtro de Kalman estendido e filtro de Kalman unscented para sistemas não-lineares. A covariância de incertezas de processo é estimada em tempo real através de média móvel exponencial. Simulações numéricas de sistema massa-mola-amortecedor não-linear, bola e barra (instável), e quatro tanques (múltiplas entradas múltiplas saídas e fase não mínima) foram realizadas para ilustrar o bom desempenho com boas estimativas e baixos tempos de execução obtido dos algoritmos propostos.CAPESThe Kalman filter is one of the most widely used methods for state estimation and control purposes. However, it requires correct knowledge of noise statistics in order to obtain optimal performance in real-life applications. Therefore, this work presents a novel approach to adapt the process noise covariance applied in nonlinear systems by using the extended Kalman filter and unscented Kalman filter. The changes of process noise covariance are estimated in real-time based on exponential moving average. The great performance of the proposed algorithms shown by good estimations with low execution time is demonstrated with numerical simulations through examples: nonlinear mass-spring-damper system, ball beam (unstable), and four tank (multiple input multiple output and non minimal phase)

Convex Model Predictive Control for Down-regulation Strategies in Wind Turbines

Wind turbine (WT) controllers are often geared towards maximum power extraction, while suitable operating constraints should be guaranteed such that WT components are protected from failures. Control strategies can be also devised to reduce the generated power, for instance to track a power reference provided by the grid operator. They are called down-regulation strategies and allow to balance power generation and grid loads, as well as to provide ancillary grid services, such as frequency regulation. Although this balance is limited by the wind availability and grid demand, the quality of wind energy can be improved by introducing down-regulation strategies that make use of the kinetic energy of the turbine dynamics. This paper shows how the kinetic energy in the rotating components of turbines can be used as an additional degree-of-freedom by different down-regulation strategies. In particular we explore the power tracking problem based on convex model predictive control (MPC) at a single wind turbine. The use of MPC allows us to introduce a further constraint that guarantees flow stability and avoids stall conditions. Simulation results are used to illustrate the performance of the developed down-regulation strategies. Notably, by maximizing rotor speeds, and thus kinetic energy, the turbine can still temporarily guarantee tracking of a given power reference even when occasional saturation of the available wind power occurs. In the study case we proved that our approach can guarantee power tracking in saturated conditions for 10 times longer than with traditional down-regulation strategies.Comment: 6 pages, 2 figures, 61st IEEE Conference on Decision and Control 202

A FAST.Farm and MATLAB/Simulink interface for wind farm control design

Increasing the efficiency of wind farms is important for speeding up the transition from fossil fuels to renewable energy sources. Current wind farm control relies on maximization of power generation of individual turbines. However, research has demonstrated that plant-wide wind farm control could optimize the performance of a wind farm. Wind farm simulation tools are crucial in designing, testing, and validating wind farm controls. FAST.Farm is a recently developed multi-physics engineering tool for modeling wind farm performance by solving the aero-hydro-servoelastic dynamics of each individual turbine. The capabilities of FAST.Farm for control design purposes can be extended through a co-simulation with MATLAB/Simulink. Therefore, a MATLAB/Simulink interface with FAST.Farm has been developed. The creation and operation of this interface are explained in this paper. This interface supports developing and testing advanced closed-loop control at the wind turbine and wind farm levels.A FAST.Farm and MATLAB/Simulink interface for wind farm control designpublishedVersio

Genome analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea

Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared t

Fiber Optic Sensing System for Temperature and Gas Monitoring in Coal Waste Pile Combustion Environments

International audienceIt is presented an optical fiber sensing system projected to operate in the demanding conditions associated with coal waste piles in combustion. Distributed temperature measurement and spot gas sensing are requirements for such a system. A field prototype has been installed and is continuously gathering data, which will input a geological model of the coal waste piles in combustion aiming to understand their dynamics and evolution. Results are presented on distributed temperature and ammonia measurement, being noticed any significant methane emission in the short time period considered. Carbon dioxide is also a targeted gas for measurement, with validated results available soon. The assessment of this technology as an effective and reliable tool to address the problem of monitoring coal waste piles in combustion opens the possibility of its widespread application in view of the worldwide presence of coal related fires

The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected

Working group on cephalopod fisheries and life history (Wgceph; outputs from 2022 meeting)

Rapports Scientifiques du CIEM. Volume 5, nº 1WGCEPH worked on six Terms of Reference. These involved reporting on the status of stocks; reviewing advances in stock identification, assessment for fisheries management and for the Ma- rine Strategy Framework Directive (MSFD), including some exploratory stock assessments; re- viewing impacts of human activities on cephalopods; developing identification guides and rec- ommendations for fishery data collection; describing the value chain and evaluating market driv- ers; and reviewing advances in research on environmental tolerance of cephalopods. ToR A is supported by an annual data call for fishery and survey data. During 2019–2021, com- pared to 1990–2020, cuttlefish remained the most important cephalopod group in terms of weight landed along the European North Atlantic coast, while loliginid squid overtook octopus as the second most important group. Short-finned squid remained the least important group in land- ings although their relative importance was almost double in 2019–2022 compared to 1992–2020. Total cephalopod landings have been fairly stable since 1992. Cuttlefish landings are towards the low end of the recent range, part of a general downward trend since 2004. Loliginid squid landings in 2019 were close to the maximum seen during the last 20 years but totals for 2020 and 2021 were lower. Annual ommastrephid squid landings are more variable than those of the other two groups and close to the maximum seen during 1992– 2021. Octopod landings have generally declined since 2002 but the amount landed in 2021 was higher than in the previous four years. Under ToR B we illustrate that the combination of genetic analysis and statolith shape analysis is a promising method to provide some stock structure information for L. forbsii. With the sum- mary of cephalopod assessments, we could illustrate that many cephalopod species could al- ready be included into the MSFD. We further provide material from two reviews in preparation, covering stock assessment methods and challenges faced for cephalopod fisheries management. Finally, we summarise trends in abundance indices, noting evidence of recent declines in cuttle- fish and some octopuses of the genus Eledone. Under ToR C, we describe progress on the reviews of (i) anthropogenic impacts on cephalopods and (ii) life history and ecology. In relation to life history, new information on Eledone cirrhosa from Portugal is included. Under ToR D we provide an update on identification guides, discuss best practice in fishery data collection in relation to maturity determination and sampling intensity for fishery monitoring. Among others, we recommend i) to include the sampling of cephalopods in any fishery that (a) targets cephalopods, (b) targets both cephalopods and demersal fishes or (c) takes cephalopods as an important bycatch, ii) Size-distribution sampling, iii) the use of standardized sampling pro- tocols, iv) an increased sampling effort in cephalopod. Work under ToR E on value chains and market drivers, in conjunction with the Cephs & Chefs INTERREG project, has resulted in two papers being submitted. Abstracts of these are in the report. Finally, progress under ToR F on environmental tolerance limits of cephalopods and climate en- velope models is discussed, noting the need to continue this work during the next cycle.info:eu-repo/semantics/publishedVersio

Search for charginos in e+e- interactions at sqrt(s) = 189 GeV

An update of the searches for charginos and gravitinos is presented, based on a data sample corresponding to the 158 pb^{-1} recorded by the DELPHI detector in 1998, at a centre-of-mass energy of 189 GeV. No evidence for a signal was found. The lower mass limits are 4-5 GeV/c^2 higher than those obtained at a centre-of-mass energy of 183 GeV. The (\mu,M_2) MSSM domain excluded by combining the chargino searches with neutralino searches at the Z resonance implies a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 31.0 GeV/c^2 for tan(beta) \geq 1.Comment: 22 pages, 8 figure

Search for composite and exotic fermions at LEP 2

A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172 GeV and 161 GeV. The search for pair-produced new leptons establishes 95% confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio

Search for lightest neutralino and stau pair production in light gravitino scenarios with stau NLSP

Promptly decaying lightest neutralinos and long-lived staus are searched for in the context of light gravitino scenarios. It is assumed that the stau is the next to lightest supersymmetric particle (NLSP) and that the lightest neutralino is the next to NLSP (NNLSP). Data collected with the Delphi detector at centre-of-mass energies from 161 to 183 \GeV are analysed. No evidence of the production of these particles is found. Hence, lower mass limits for both kinds of particles are set at 95% C.L.. The mass of gaugino-like neutralinos is found to be greater than 71.5 GeV/c^2. In the search for long-lived stau, masses less than 70.0 to 77.5 \GeVcc are excluded for gravitino masses from 10 to 150 \eVcc . Combining this search with the searches for stable heavy leptons and Minimal Supersymmetric Standard Model staus a lower limit of 68.5 \GeVcc may be set for the stau mas