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Prediction-observer Scheme for Linear Systems with Input-output Time-delay
Varinia Fragoso-Rubio,Martín Velasco-Villa,Miguel A. Hernández-Pérez,Basilio del Muro-Cuéllar,Juan Francisco Márquez-Rubio 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.8
This work deals with the prediction and control problems associated with a class of linear systems with time-delay at the input-output path. A general prediction observer scheme that estimates the future value of the delayed system from the output is proposed. Later, a full-information predictor-observer is introduced and the convergence of the estimated future values is formally proven for a time-delay τ of any size by increasing the dimension of the proposed predictor-observer. The estimated future state is used to design a feedback law that compensates the delay effects on the original system. The performance of the prediction-observation control strategy is shown by means of numerical simulations. Thus, it is illustrated that the performance of the proposed full-information predictor-observer is improved with respect to the sequential sub-predictors previously presented in the literature.
Feedback Control Based on a Sequential Observer-predictor for Systems with Unknown Actuator Delay
David Fernando Novella-Rodríguez,Juan Carlos Tudon-Martínez,Rocio Jasmin Vazquez-Guerra,Juan Francisco Márquez-Rubio 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.9
The present work is devoted to the stabilization of linear systems with input delay, where the delay value can be arbitrarily long with respect to the system response. The time-delay is considered unknown or incorrectly modeled. A sequential observer with variable time-delays is designed in order to predict the system states before the delay occurs. The delays in the sequential observer-predictor are updated by means of a delay estimation in order to obtain an accurate state prediction. The stability of the closed-loop system and the convergence of the observers are analyzed by considering the separation principle. Numerical simulations are performed to evaluate the proposed sequential observer-controller under different scenarios.
High-performance circular sawing of AISI 1045 steel with cermet and tungsten carbide inserts
A. M. Abrão,M. C. Moreira,P. E. Faria,J. C. Campos Rubio 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.10
This work investigated the influence of cutting speed and feed rate on cutting forces, surface roughness, and slot width circular sawingof AISI 1045 steel. The effects of tool material (cermet and tungsten carbide) and geometry (chip breaker flute and pre-cutting/postcuttingteeth) were also investigated. Thrust and radial forces generally tended to decrease as the cutting speed increased and tended toincrease with the feed rate. The lowest values of thrust and radial forces were obtained using a tungsten carbide saw ground with precuttingand post-cutting teeth. With regard to the quality of the machined wall, the lowest surface roughness was obtained by applying thehighest cutting speed and lowest feed rate and employing a cermet brazed saw. Under this condition, roughness values comparable toface turning and parting off operations were obtained. The cermet brazed saw was responsible for producing the narrowest slot widths.
Higuera-Rubio Jesús M.,Ibarra-Laclette Enrique,Reyes-López Miguel A.,Sandoval-Castro Eduardo,Cruz-Mendívil Abraham,Vega-García Misael O.,Calderón-Vázquez Carlos L. 한국식물생명공학회 2022 Plant biotechnology reports Vol.16 No.4
This study aims to disentangle avocado enzymatic browning by identifying and analyzing the PPO coding genes. Two avocado accessions (AVO48 and San Miguel) and the Hass cultivar with contrasting browning kinetics and enzyme activity levels were selected for gene characterization. Upon 90 min of light exposure, Hass and San Miguel showed a greater decrease in luminosity retention (closer to 40% of initial luminosity) compared to AVO48 (85% of luminosity). PPO activity in crude extracts was significantly higher (P < 0.05) in San Miguel (696 U μg-1 protein) than Hass (174 U μg-1 protein) and AVO48 (46–56 U μg-1 protein). San Miguel showed a higher Vmax Km-1 ratio (20.88 min-1), followed by Hass (14.29 min-1) and AVO48 (1.64 min-1), suggesting that San Miguel and Hass have higher substrate affinity. Four PPO coding genes: PamPPO1, PamPPO2, PamPPO3 and PamPPO4 were identified in the Hass genome, all of them containing the main features of plant PPOs, but with specific amino acid combinations in the catalytic pocket of the tyrosinase domain; suggesting that PPO1, PPO2 and PPO4 have monophenolase activity, whereas PPO3, has o-diphenolase activity. The evidence of transcription of PPO3 in fruit of the three genotypes suggests an important role for this gene in avocado pulp browning. PPO2 expression was only found in AVO48. This research provides gene candidates for selective silencing to reduce enzymatic browning.
COCCIDIOSIS CONTROL IN THE EUROPEAN UNION. CURRENT SITUATION AND FUTURE CHALLENGES
Marc Pagès,M. Dardi,M. de Gussem,J. Rubio,R. March,M. Shirley,D. Blake,E. del Cacho 한국가금학회 2012 한국가금학회 심포지움 Vol.2012 No.5
Avian coccidiosis is one of the most important diseases affecting the intensive poultry industry worldwide. Despite its outstanding importance and well-known relation with other factors that may influence the health status of the birds and its commercial performance, few studies are available on the distribution of Eimeria species in the field. In Europe the studies available until the present date are, Czech Republic(Kučera, 1990), France(Williams, 1996), UK(Chapman, 1982, Shirley 1995, Shirley 1997, Williams 2006, Eckert 1995), Norway(Haug, 2008)and Sweden(Thebo, 1998). Most of the published studies have been focused on identifying the seven species of Eimeria which affect Gallus gallus in a European country. However, the only survey that has been done exclusively with samples from broiler farms of Norway is Haug, 2008. In the present study, litter samples obtained in broiler farms from Spain, Belgium, Italy and France were evaluated for the presence of Eimeria species. The evaluation was done using a polymerase chain reaction(PCR) developed at IAH to specifically detect E.acervulina, E.maxima, E.mitis, E.praecox and E.tenella. Together with this molecular tool, oocyst counts and a morphometric evaluation test were also used to analyse the samples. Results obtained provide interesting data on the prevalence of species which affect the broiler birds in Europe as well as the percentage of farms with presence of each species. Together with prevalence data, rotation programs(anticoccidials-vaccines) appear to be of paramount importance to upgrade the flock performances. Data obtained in farms from the Netherlands confirms the advantage of using rotation programs with vaccines composed of Eimeria strains sensitive to anticoccidials.
Romulo Maziero,Washington M. Cavalcanti,Bruno D. Castro,Claudia V. Campo, Rubio,Luciano M.G. Vieira,Tulio H. Panzera,Juan C. Campos Rubio Techno-Press 2023 Advances in materials research Vol.12 No.2
The development of sustainable composites materials, from recycled polymeric materials and waste from the wood industry and stone processing, allows reducing the volume of these by-products, minimizing impacts on health and the environment. Nowadays, Polypropylene (PP) is the most recycled polymer in industry, while the furniture industry has increasingly used timber felled from sustainable forest plantations as a eucalypt. The powder tailing from the ornamental stone extraction and processing industry is commonly disposed of in the environment without previous treatment. Thus, the technological option for the development of composite materials presents itself as a sustainable alternative for processing and manufacturing industries, enabling the development of new materials with special technical features. The results showed that powder granite particles may be incorporated into the polypropylene matrix associated with short eucalyptus fibres forming green hybrid composites with potential application in structural engineering, such as transport and civil construction industries.
Effect of laser shock peening and cold expansion on fatigue performance of open hole samples
Rubio-Gonzalez, Carlos,Gomez-Rosas, G.,Ruiz, R.,Nait, M.,Amrouche, A. Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.5
Mechanical fastening is still one of the main methods used for joining components. Different techniques have been applied to reduce the effect of stress concentration of notches like fastener holes. In this work we evaluate the feasibility of combining laser shock peening (LSP) and cold expansion to improve fatigue crack initiation and propagation of open hole specimens made of 6061-T6 aluminum alloy. LSP is a new and competitive technique for strengthening metals, and like cold expansion, induces a compressive residual stress field that improves fatigue, wear and corrosion resistance. For LSP treatment, a Q-switched Nd:YAG laser with infrared radiation was used. Residual stress distribution as a function of depth was determined by the contour method. Compact tension specimens with a hole at the notch tip were subjected to LSP process and cold expansion and then tested under cyclic loading with R=0.1 generating fatigue cracks on the hole surface. Fatigue crack initiation and growth is analyzed and associated with the residual stress distribution generated by both treatments. It is observed that both methods are complementary; cold expansion increases fatigue crack initiation life, while LSP reduces fatigue crack growth rate.