43 research outputs found

    Advanced PID Control Optimisation and System Identification for Multivariable Glass Furnace Processes by Genetic Algorithms

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    This thesis focuses on the development and analysis of general methods for the design of optimal discrete PID control strategies for multivariable glass furnace processes, where standard genetic algorithms (SGAs) are applied to optimise specially formulated objective functions. Furthermore, a strong emphasis is given on the realistic model parameters identi cation method, which is illustrated to be applicable to a wide range of higher order model parameters identi cation problems. A complete, realistic and continuous excess oxygen model with nonlinearity effect was developed and the model parameters were identified. The developed excess oxygen model consisted of three sub-models to characterise the real plant response. The developed excess oxygen model was evaluated and compared with real plant dynamic response data, which illustrated the high degree of accuracy of the developed model. A new technique named predetermined time constant approximation was proposed to make an assumption on the initial value of a predetermined time constant, whose motive is to facilitate the SGAs to explore and exploit an optimal value for higher order of continuous model's parameters identi cation. Also, the proposed predetermined time constant approximation technique demonstrated that the population diversity is well sustained while exploring the feasible search region and exploiting to an optimal value. In general, the proposed method improves the SGAs convergence rate towards the global optimum and illustrated the effectiveness. An automatic tuning of decentralised discrete PID controllers for multivariable processes, based on SGAs, was proposed. The main improvement of the proposed technique is the ability to enhance the control robustness and to optimise discrete PID parameters by compensating the loop interaction of a multivariable process. This is attained by adding the individually optimised objective function of glass temperature and excess oxygen processes as one objective function, to include the total effect of the loop interaction by applying step inputs on both set points, temperature and excess oxygen, at two different time periods in one simulation. The effectiveness of the proposed tuning technique was supported by a number of simulation results using two other SGAs conventional tuning techniques with 1st and 2nd order control oriented models. It was illustrated that, in all cases, the resulting discrete PID control parameters completely satisfied all performance specifications. A new technique to minimise the fuel consumption for glass furnace processes while sustaining the glass temperature is proposed. This proposed technique is achieved by reducing the excess oxygen within the optimum thermal efficiency region within 1.7% to 3.2%, which is approximately equal to about 10% to 20% of excess air. Therefore, by reducing the excess oxygen set point within the optimum region, 2.45% to 2%, the fuel consumption is minimised from 0:002942kg/sec to 0:002868kg/sec while the thermal efficiency of the glass temperature is sustained at the desired set point (1550K). In addition, a reduction in excess oxygen within methane combustion guidelines will assure that undesirable emissions are in control throughout the combustion process. The efficiencies of the proposed technique were supported by a number of simulation results applying the three SGAs controller tuning techniques. It was illustrated that, in all cases, the fraction of excess oxygen reduction results in a great minimisation of fuel consumption over long plant operating periods

    An improved search space resizing method for model identification by standard genetic algorithm

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    In this paper, a new improved search space boundary resizing method for an optimal model’s parameter identification for continuous real time transfer function by standard genetic algorithms (SGAs) is proposed and demonstrated. Premature convergence to local minima, as a result of search space boundary constraints, is a key consideration in the application of SGAs. The new method improves the convergence to global optima by resizing or extending the upper and lower search boundaries. The resizing of the search space boundaries involves two processes, first, an identification of initial value by approximating the dynamic response period and desired settling time. Second, a boundary resizing method derived from the initial search space value. These processes brought the elite groups within feasible boundary regions by consecutive execution and enhanced the SGAs in locating the optimal model’s parameters for the identified transfer function. This new method is applied and examined on two processes, a third-order transfer function model with and without random disturbance and raw data of excess oxygen. The simulation results assured the new improved search space resizing method’s efficiency and flexibility in assisting SGAs to locate optimal transfer function model parameters in their explorations

    PID controller tuning for a multivariable glass furnace process by genetic algorithm

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    Standard genetic algorithms (SGAs) are investigated to optimise discrete-time proportional-integral-derivative (PID) controller parameters, by three tuning approaches, for a multivariable glass furnace process with loop interaction. Initially, standard genetic algorithms (SGAs) are used to identify control oriented models of the plant which are subsequently used for controller optimisation. An individual tuning approach without loop interaction is considered first to categorise the genetic operators, cost functions and improve searching boundaries to attain the desired performance criteria. The second tuning approach considers controller parameters optimisation with loop interaction and individual cost functions. While, the third tuning approach utilises a modified cost function which includes the total effect of both controlled variables, glass temperature and excess oxygen. This modified cost function is shown to exhibit improved control robustness and disturbance rejection under loop interaction. © 2015 Institute of Automation, Chinese Academy of Sciences and Springer-Verlag Berlin Heidelber

    Agrárpiaci Jelentések, Baromfi

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    A Rabobank jelentése szerint világszinten a baromfiipar erősödésére lehet számítani 2014 utolsó negyedévében. A világ legtöbb régiójában kedvezőek a piaci árrések és a gabonapiaci kilátások alapján a termelési költségek további mérséklődése várható. Az Európai Unió baromfiágazatára az élénk kereslet és a korlátozott kínálat a jellemző. Az EU baromfihúsexportja 2,5 százalékkal bővült, baromfihúsimportja 0,5 százalékkal 484 ezer tonnára csökkent 2014 első félévében az előző év hasonló időszakához képest. Az Európai Bizottság adatai alapján 2014 első harmincnyolc hetében 194,04 euró/100 kg volt az egész csirke uniós átlagára, ami 1,5 százalékkal maradt el az előző év azonos időszakának átlagárától. Magyarországon a vágócsirke élősúlyos termelői ára (276 forint/kg) 7 százalékkal volt alacsonyabb 2014 első harmincnyolc hetében az egy évvel korábbinál

    An improved search space resizing method for model identification by Standard Genetic Algorithm

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    .In this paper, a new improved search space boundary resizing method for an optimal model's parameter identification by Standard Genetic Algorithms (SGAs) is proposed and demonstrated. The premature convergence to local minima, as a result of search space boundary constraints, is a key consideration in the application of SGAs. The new method improves the convergence to global optima by resizing or extending the upper and lower search boundaries. The resizing of search space boundaries involves two processes, first, an identification of initial value by approximating the dynamic response period and desired settling time. Second, a boundary resizing method derived from the initial search space value. These processes brought the elite groups within feasible boundary regions by consecutive execution and enhanced the SGAs in locating the optimal model's parameters for the identified transfer function. This new method is applied and examined on two processes, a third order transfer function model with and without random disturbance and raw data of excess oxygen. The simulation results assured the new improved search space resizing method's efficiency and flexibility in assisting SGAs to locate optimal transfer function model parameters in their explorations. © 2015 Chinese Automation and Computing Society in the UK - CAC

    Decentralised Control Optimisation for a Glass Furnace by SGA’s

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    In this paper, the potential of standard genetic algorithms (SGAs) are presented to optimise the discrete PID parameters for multivariable glass furnace. Control oriented models of each multivariable glass furnace; glass temperature and excess oxygen are used to optimise the discrete controller with personalised cost function and adjusted boundaries by SGAs, individually. Well optimised discrete PID parameters by control oriented model are applied to realistic multivariable model by decentralised method

    Impact of the orientation of seed placement and depth of its sowing on germination: A review

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    Seed orientation and its impacts on germination and seedling establishment mainly depend on the type of germination (hypogeal (or) epigeal), seed size and shape. Higher germination per cent is noticed when seeds are sown in the horizontal position. Planting seeds in a downward position can lead to a variety of physiological, chemical and morphological changes in seedlings. Consequences are usually manifested as noticeable modifications in their development. Vigorous seeds have strong, resilient seedlings due to their well-balanced metabolism and coordinated subcellular activity, making them well-suited for tough environments. Proper plumule and radicle growth require additional hormones and energy to ensure seedling survival. Four necessary factors must be considered while deciding the sowing depth viz., soil moisture, optimum soil temperature, soil aeration and atmospheric humidity required for seed germination, emergence and seedling growth. Variations are observed in germination behaviour and seedling growth for different sowing depths. The necessary factors are very much important for efficient nursery seedlings production. This review looks at the effects of seed depth and orientation on the germination and growth of important agricultural, horticultural and silvicultural crops

    Sapper: A Language for Hardware- Level Security Policy Enforcement

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    Privacy and integrity are important security concerns. These concerns are addressed by controlling information flow, i.e., restricting how information can flow through a system. Most proposed systems that restrict information flow make the implicit assumption that the hardware used by the system is fully “correct ” and that the hardware’s instruction set accurately describes its behavior in all circumstances. The truth is more complicated: modern hardware designs defy complete verification; many aspects of the timing and ordering of events are left totally unspecified; and implementation bugs present themselves with surprising frequency. In this work we describe Sapper, a novel hardware description language for designing security-critical hardware components. Sapper seeks to address these problems by using static analysis a

    Optimization and characterization of green synthesized silver nanoparticles and its inhibitory activity against biofilm forming bacterial pathogens

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    In the present study, antibacterial activity of silver nanoparticles synthesized from entophytic fungi extracts were analysed against biofilm forming bacteria include the Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa isolated from clinical specimens. Therefore, we tried to establish a combination of medicinal and nanotechnology possibly with the field of medicine for the development of antibacterial agents against these strains. The nanoparticles were characterized by UV–visible spectroscopy, the presented and capped molecules of proteins with nanoparticles was confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD). UV–visible studies display an absorption band at 420 nm due to surface Plasmon resonance (SPR) of the silver nanoparticles. The intra cellular synthesized silver nanoparticles (Ag NPs) size 15-35 nm was determination of X-ray diffraction (XRD) crystal calculation, antimicrobial activity higher than the standard antibiotic. The nanoparticle treated with isolated bacteria as result macromolecule of proteins denatures and oozing out the cells and measure the Bradford method. The nanoparticle treated bacterial cells were compared to negative control more amount of protein released. The nano size establishing the silver nanoparticles directly bind with DNA of the pathogenic bacterial strains most important to higher antimicrobial activity

    Metroglyph analysis of morphological variations in Sorghum germplasm collections

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    An experiment was conducted during kharif 2008, to assess the pattern of morphological variations through metroglyphtechnique in local land races of Sorghum collected from different parts of Tamil Nadu. Based on this technique, geneticvariability was evaluated for five characters viz., grain yield / plant (g), fodder yield / plant (g), grain size (g), 1000 grainweight and ear head compactness among 63 accessions. The mean values were used for plotting the accessions in agraph. All accessions were grouped into eight distinct groups, which differed amongst themselves. Group II was thelargest comprising 25 accessions followed by Group V having 13 accessions with moderate grain yield and fodder yield.Group VI consisted of 3 accessions with high yield and medium fodder yield besides moderate 1000 grain weight andear head compactness. Group VIII had 3 accessions classified into medium grain yield with high fodder yield consistingof compact ear head and bold grains. Land races are the primitive cultivars which are selected and cultivated by farmersfor many generations. Land races have more genetic diversity, wider adaptability and high degree of resistance to bioticand abiotic stresses and even respond to selection for high yield. In the present world of research, great strides in sorghumimprovement have been made by transforming the local land races into more productive forms through hybridization toevolve highly adapted hybrids. Since, sorghum is the dual purpose crop, the germplasm lines of Group III, VI, VII andV could be helpful in future breeding programme for achieving higher grain yield, yield components and fodder yield.The study, therefore, indicated the possibility of producing dual purpose sorghum hybrids by combining desirablegermplasm accessions
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