172 research outputs found

    Seřizování regulátorů PID pro lineární dynamické systémy metodou “Hrubé síly a od oka”

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    For PID controllers in control loops, which in practice still prevails, it is necessary to determine controller parameter values which assure sufficient quality and robustness of control. A lot of PID tuning methods is described and well established in daily use. They are often based either on behavior of closed control loop or on a mathematic model of the controlled plant (and its L-transfer function), which allow to determine controller parameters by direct calculation. With increasing computing power of HW and SW aids it could be beneficial to use a method for determining the optimal setting of PID controller by simulation of control loop behavior for various meaningful combinations of controller parameter values (state space search). Proposed method “brute force and visual” of PID controller tuning is based on repeated simulation of control process as a reaction to Heaviside step of desired value and disturbing value for varying parameters of controller’s P, I, D components. For discrete controller also impact of sampling period T was considered. For each of the individual simulation runs there is kept a diagram as an image file as well as the control optimality criterion value. After execution of all the simulation runs for parameter values from the considered searched state space the simulation outputs are sorted by value of the selected control optimality criterion. The parameters of the individual simulation which has scored best are used for setting of the real controller and evaluated in the real control loop. From the simulations available for wide combination of parameter values it is possible to estimate position of isles of stability and choose the PID controller values by an expert choice.Při návrhu parametrů PID regulátoru (které jsou v praxi dosud nejobvyklejší) pro regulační obvody je zapotřebí stanovit parametry regulátoru tak, aby zajišťovaly dostatečnou kvalitu a robustnost regulace. Je definováno a v praxi zavedeno mnoho seřizovacích metod pro nastavení PID regulátorů vycházejících z chování uzavřeného regulačního obvodu či naopak z matematického modelu regulované soustavy (a jejího L-přenosu), které umožňují stanovit parametry regulátoru přímým výpočtem. S rostoucím výkonem HW a SW nástrojů může ale být výhodné použít přístup, který nalezne optimální hodnoty nastavení regulačního procesu na základě simulací a analýzy chování regulačního obvodu pro různé kombinace možných parametrů regulátoru. Navržená metoda seřízení PID regulátoru lineárního dynamického systému „hrubou silou a od oka“ je založena na opakované simulaci regulačního pochodu při skoku řídící veličiny a poruchové veličiny pro měnící se konstanty regulátoru P, I, D, (a v případě číslicového regulátoru i vzorkovací periodu T) pro smysluplné rozpětí hodnot – odtud „hrubou silou“ v názvu metody. Z každého běhu simulace je uložen diagram průběhů zajímavých veličin (žádaná veličina, regulovaná veličina, porucha) jako obrazový soubor a jsou pro tuto simulaci vypočteny hodnoty ukazatelů kvality regulace. Po provedení simulací pro všechny hodnoty parametrů z uvažovaného stavového prostoru jsou výstupy simulací setříděny podle ukazatelů kvality regulace; simulace s parametry regulace, která skórovala podle ukazatelů kvality regulace nejlépe, je pak podkladem pro nastavení parametrů regulátoru a ověření v reálném regulačním obvodu. Protože máme k dispozici vizualizované podoby průběhů regulačního procesu pro mnoho kombinací vstupů, můžeme odhadnout i polohu a podobu „ostrovů stability“ a pro dosažení robustnější regulace volit parametry regulátoru i expertní volbou, tedy „od oka“

    Differences and similarities between the EULAR/ASAS-EULAR and national recommendations for treatment of patients with psoriatic arthritis and axial spondyloarthritis across Europe

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    This is the first report comparing EULAR and national treatment recommendations for PsA patients across Europe, and the first this decade to compare ASAS-EULAR and national treatment recommendations in axSpA patients. An electronic survey was completed from October 2021-April 2022 by rheumatologists in 15 European countries. One and four countries followed all EULAR and ASAS-EULAR recommendations, respectively. Five countries had no national treatment recommendations for PsA and/or axSpA, but followed other regulations. In several countries, national treatment recommendations predated the most recent EULAR/ASAS-EULAR recommendations. Entry criteria for starting biologic/targeted synthetic disease-modifying anti-rheumatic drugs varied considerably. In several countries, for PsA patients with significant skin involvement, interleukin-17 inhibitors were not given preference. The positioning of Janus Kinase inhibitors differed and Phosphodiesterase-4 inhibitors were not in use/reimbursed in most countries. This study may motivate European countries to update their national treatment recommendations, to align them better with the latest international recommendations

    Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

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    Peer reviewe

    Návrh RTK pro montáž a zkoušení ventilových bloků důlních spojek

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    Import 20/04/2006Prezenční výpůjčkaFakulta strojní VŠB (Ostrava). Katedra (354) robototechnik

    DataSheet1_Modes and geometry of crustal-scale detachment folding in hot orogens—Insights from physical modeling.pdf

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    Detachment folding can be defined as the displacement and buckling of a competent layer above a rheologically weak horizon during tectonic shortening, frequently addressed in the context of salt tectonics. More recent studies have focused on influence of detachments in large-scale lithospheric deformation where the detachment horizon is represented by partially molten lower crust.This study addresses the geometric, kinematic and dynamic behavior of crustal-scale detachment folds using heated paraffin wax as an analogue for partially molten lower crust. Various thermal and shortening rate scenarios were tested in order to characterize deformation patterns within hot orogens in general, and to find an appropriate range of temperature gradients and shortening rates for the detachment folding regime. Five different regimes of lower crustal deformation were identified: 1. Homogeneous thickening or bulging, 2. Short-wavelength folding, 3. Development of diapir-shape folds or ductile faults, 4. Detachment folding and 5. Formation of lower crustal finger-like protrusions.Models are compared to various natural prototypes worldwide, in particular a series of metamorphic domes in the Central Asian Orogenic Belt (CAOB). Detailed analysis of the kinematic-dynamic evolution of the detachment folding scenario revealed an asymmetrical evolution of the folds associated with rotation of the limbs, as well as flexural flow of the lower weak mushy crust around the molten core. Pressure gradients in the fold cores saturated by melt controlled the sequential injections and outflows of partially/molten material between folds’ cores and the melt source layer at the base of the system. This resulted in accumulation of melt in the foreland of the accretionary zone, with higher melt absorption potential for newly developed folds. These observations may have significant implications for the development of pseudo-symmetrical metamorphic domes in the CAOB.</p

    DataSheet4_Modes and geometry of crustal-scale detachment folding in hot orogens—Insights from physical modeling.zip

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    Detachment folding can be defined as the displacement and buckling of a competent layer above a rheologically weak horizon during tectonic shortening, frequently addressed in the context of salt tectonics. More recent studies have focused on influence of detachments in large-scale lithospheric deformation where the detachment horizon is represented by partially molten lower crust.This study addresses the geometric, kinematic and dynamic behavior of crustal-scale detachment folds using heated paraffin wax as an analogue for partially molten lower crust. Various thermal and shortening rate scenarios were tested in order to characterize deformation patterns within hot orogens in general, and to find an appropriate range of temperature gradients and shortening rates for the detachment folding regime. Five different regimes of lower crustal deformation were identified: 1. Homogeneous thickening or bulging, 2. Short-wavelength folding, 3. Development of diapir-shape folds or ductile faults, 4. Detachment folding and 5. Formation of lower crustal finger-like protrusions.Models are compared to various natural prototypes worldwide, in particular a series of metamorphic domes in the Central Asian Orogenic Belt (CAOB). Detailed analysis of the kinematic-dynamic evolution of the detachment folding scenario revealed an asymmetrical evolution of the folds associated with rotation of the limbs, as well as flexural flow of the lower weak mushy crust around the molten core. Pressure gradients in the fold cores saturated by melt controlled the sequential injections and outflows of partially/molten material between folds’ cores and the melt source layer at the base of the system. This resulted in accumulation of melt in the foreland of the accretionary zone, with higher melt absorption potential for newly developed folds. These observations may have significant implications for the development of pseudo-symmetrical metamorphic domes in the CAOB.</p

    DataSheet2_Modes and geometry of crustal-scale detachment folding in hot orogens—Insights from physical modeling.zip

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    Detachment folding can be defined as the displacement and buckling of a competent layer above a rheologically weak horizon during tectonic shortening, frequently addressed in the context of salt tectonics. More recent studies have focused on influence of detachments in large-scale lithospheric deformation where the detachment horizon is represented by partially molten lower crust.This study addresses the geometric, kinematic and dynamic behavior of crustal-scale detachment folds using heated paraffin wax as an analogue for partially molten lower crust. Various thermal and shortening rate scenarios were tested in order to characterize deformation patterns within hot orogens in general, and to find an appropriate range of temperature gradients and shortening rates for the detachment folding regime. Five different regimes of lower crustal deformation were identified: 1. Homogeneous thickening or bulging, 2. Short-wavelength folding, 3. Development of diapir-shape folds or ductile faults, 4. Detachment folding and 5. Formation of lower crustal finger-like protrusions.Models are compared to various natural prototypes worldwide, in particular a series of metamorphic domes in the Central Asian Orogenic Belt (CAOB). Detailed analysis of the kinematic-dynamic evolution of the detachment folding scenario revealed an asymmetrical evolution of the folds associated with rotation of the limbs, as well as flexural flow of the lower weak mushy crust around the molten core. Pressure gradients in the fold cores saturated by melt controlled the sequential injections and outflows of partially/molten material between folds’ cores and the melt source layer at the base of the system. This resulted in accumulation of melt in the foreland of the accretionary zone, with higher melt absorption potential for newly developed folds. These observations may have significant implications for the development of pseudo-symmetrical metamorphic domes in the CAOB.</p
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