Wyniki wyszukiwania - BazTech

1

Study of losses and energy efficiency of hydrostatic drives with hydraulic cylinder

Skorek G.

Polish Maritime Research

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2018

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nr 4

114--129

EN

Energy efficiency of hydrostatic transmissions, and especially efficiencies of drives with motor speed controlled by throttle, as well as efficiency of hydraulic servomechanisms can in fact be higher than the efficiency values most frequently given by the respective literature in this field. With the progress achieved in recent years in the development of hydraulic systems it is becoming necessary to develop methods for precise energy efficiency calculation of such systems. It is difficult to imagine that more and more, better and better machines and control elements could be used without the possibility of a mathematical tool at our disposal to enable an accurate analysis and assessment of behavior of the system in which such machines and control elements have been applied. The paper discusses energy savings using mathematical model of losses in elements, the energy efficiency of the system. There are possibilities to reduce energy losses in proportional control systems (in the pump, in the throttle control unit, especially in the cylinder), and thus to improve the energy efficiency of the throttling manifold. The considerations allow for comparison of the loss power resulting from the applied hydraulic control structure of the hydraulic cylinder and the power consumed by the pump from the electric motor that drives it, the power necessary to provide pump-driven hydraulic cylinder. The article shows the impact on the output (useful) power consumed in the considered systems, and the impact on the power consumed of the loss power in the individual elements. The paper presents also formulas of loss power, formulas of energy efficiency connected with investigated hydrostatic drives, two schematic diagrams of hydraulic systems, their principle of operation and problems of studying losses in elements and energy efficiency characteristics of systems consisting of a feed assembly, control set and cylinder. It also includes a subject matter connected with an energy loss power of hydrostatic systems with hydraulic cylinder controlled by proportional directional control valve. Diagrams of loss power of two hydraulic systems worked at the same parameters of speed and load of a cylinder, which were different due to structure and ability of energy saving, were presented and compared.

2

Evaluation of dynamic parameters of the selected components within digitally controlled hydraulic system

Kamiński M., Szlagowski J., Dąbrowski D.

Journal of KONES

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2018

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Vol. 25, No. 1

205--214

EN

Dynamic parameters characterizing proportional hydraulic components are essential factors affecting the performance of the construction machinery automatic control system. Knowledge of these parameters is inevitable in modelling the automatically controlled hydraulic power systems as well as designing and analysing the control algorithms. This article presents a methodology of assessing the dynamic parameters of selected components being part of digitally controlled hydraulic power system. The analysed system comprised a typical for mobile hydraulics applications PVG32 proportional directional control valve (DCV) and a variable displacement piston pump. The control system utilised an MC088 PLC controller with specifically prepared and configured software. The measuring system was based on CANbus, which, combined with the PLC used, allowed for flexible configuration of the sensor variables and logging both analogue and digital signals. Among others, the DCV characteristics, the response to step and sinusoidal inputs and DCV hysteresis were examined. The goal was to gather the data required for system modelling and to assess the importance and influence of the investigated parameters onto the model being created.

3

Wpływ parametrów wybranych zadajników elektrohydraulicznych na jakość regulacji uzyskiwaną przy sterowaniu położeniem tłoczyska cylindra hydraulicznego w układzie zamkniętym

Kamiński K., Szlagowski J.

Przegląd Mechaniczny

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2016

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nr 11

26--31

PL

W artykule przedstawiono wyniki badań porównawczych dwóch rodzajów zadajników elektrohydraulicznych służących do pozycjonowania suwaka w rozdzielaczu stosowanym w hydraulicznych układach mobilnych. Dla każdego z tych zadajników zbadano charakterystykę rozdzielacza, podstawowe parametry dynamiczne, takie jak odpowiedź na wymuszenie skokowe i sinusoidalne oraz histerezę. Wyniki tych badań zostały porównane z wynikami uzyskanymi podczas sterowania położeniem tłoczyska cylindra hydraulicznego w zamkniętym układzie regulacji. Celem było wyeksponowanie wpływu badanych parametrów na uzyskiwaną jakość regulacji.

EN

This paper presents the results of comparative research performed over two types of electro-hydraulic pilot valves used for spool positioning in a mobile hydraulics directional control valve (DCV). The DCV characteristic, basic dynamic parameters like step and sinusoidal input response and hysteresis were evaluated for each of these pilot valves. The results of this research were compared with the results obtained during closed loop position control of a hydraulic cylinder rod. The goal was to exhibit the influence of the investigated parameters on the obtained control quality.

4

Stanowisko do wyznaczania charakterystyk statycznych i dynamicznych zaworów proporcjonalnych

Kudźma Z., Stosiak M., Herok S.

Pomiary Automatyka Robotyka

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2014

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R. 18, nr 3

112--119

PL

W artykule przedstawiono stanowisko do wyznaczania charakterystyk statycznych i dynamicznych zaworów sterowanych w technice proporcjonalnej. Opisano układ sterujący rozdzielaczem proporcjonalnym i wielokanałowy tor sterująco-pomiarowy ze specjalistycznym oprogramowaniem umożliwiającym generowanie dowolnego w czasie przebiegu sygnału sterującego oraz na akwizycję danych pomiarowych. Przedstawiono przykładowe wyniki wyznaczania charakterystyk proporcjonalnego rozdzielacza regulacyjnego najnowszej generacji. Zamieszczono przykład zastosowania uzyskanych wyników pomiarowych do uściślenia modelu matematycznego sterowania rozruchem przekładni hydrostatycznej pod kątem minimalizacji hałasu.

EN

In the paper a test stand for determination of static and dynamic proportional valves characteristic was presented. A multichannel test stand was developed and presented in the paper. Moreover control system of proportional directional control valve and multichannel slotted line with special software for generation several control signals were presented too. Moreover some experimental tests results were presented for high-response proportional directional control valve. An example of application obtained results for mathematical model refinement of control of hydrostatic transmission start with minimum noise criterion was presented.