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Investigations of applications of smart materials and methods in fluid valves and drives

Milecki Andrzej, Rybarczyk Dominik

Journal of Machine Engineering

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2019

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Vol. 19, No. 4

122--134

EN

In the paper the investigations performed at the Division of Mechtronic Devices at Poznan University of Technology in the area of application of both: smart materials in electro-hydraulic and electro-pneumatic valves, and new methods to control of hydraulic servo drives, are presented. In a first part the piezo bender actuator is shortly described and its application in servo valve is proposed. This actuator replaced the torque motor in the available on the market servo valve. The new valve simulation model is proposed. The simulation and investigations results of the servo valve with the piezo bending actuator are included. In the next part of the paper the application of piezo tube actuator in flapper-nozzle pneumatic valve is described. The test stand and investigations results are presented. Later, in the article, the Model Following Control (MFC) and Fractional order Control (FoC) methods are described. Their application in control of electrohydraulic servo drive is proposed. Some investigations results are included in the paper, showing the advantages of those control methods.

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Investigation of electrohydraulic drive control system with the haptic joystick

Bachman P., Milecki A.

Acta Mechanica et Automatica

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2018

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Vol. 12, no. 1

5--10

EN

The term haptic is used to indicate the presence of force feedback from the manipulated object to the operator. One of the most commonly used haptic devices are joysticks. Such joysticks can be successfully applied also in communication with drive system, giving the human operator a feel of the output force. In the paper one axis joystick with force feedback used to control the electrohydraulic drive is proposed. In this joystick, a controlled brake with magnetorheological fluid and a small DC motor are applied. A beam with a strain gauge is used in a joystick arm, enabling the measurement of the force. In the joystick axis also a potentiometer is assembled, which measured the current arm position. In order to develop the control algorithms an electrohydraulic drive simulation and virtual model is worked out and then a haptic joystick is connected to it. The simulation results that have been obtained, enabled to design and test impedance and admittance control strategies for the system composed of haptic joystick and a real electrohydraulic drive. Finally the whole system is built, implemented and investigated in a laboratory environment. Investigations are conducted in conditions similar to real ones, in a situation where hydraulic piston touches an obstacle and the operator cannot observe this piston very accurately. Fifteen operators have been tested this way. The outcomes indicate that haptic control can improve the human feeling of forces between electrohydraulic drive and an obstacle and, thanks to this, the manual control is more accurate and safer.

3

Modelling and investigations of electrohydraulic servo valve with piezo element

Milecki A.

Archiwum Technologii Maszyn i Automatyzacji

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2006

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Vol. 26, nr 2

177-184

EN

The paper presents the new concept of electrohydraulic servo valve with piezo bender actuator. The main properties of piezo elements are described. The theoretical and simulation model of valve with this element is proposed and discussed in the paper. The chosen simulation results are presented and discussed. These results are compared with laboratory investigations. The advantages and disadvantages of described servo valve are shortly demonstrated.

PL

W artykule zaprezentowano nową koncepcje serwozaworu elektrohydraulicznego z płytkowym przetwornikiem piezoelektrycznym. Zaproponowano model teoretyczny oraz symulacyjny tego zaworu. Pokazano i omówiono wybrane rezultaty badań symulacyjnych proponowanego serwozaworu. Porównano je z wynikami badań doświadczalnych zbudowanego serwozaworu. Krótko scharakteryzowano podstawowe wady i zalety zaproponowanego rozwiązania.

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Systemy i komponenty firmy Bosch Rexroth stosowane w górnictwie

Kołdras A.

Napędy i Sterowanie

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2005

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R. 7, nr 4

70--72

PL

Wśród wielu branż przemysłu, dla których systemy i komponenty oferuje firma Bosch Rexroth, znalazły się produkty mające zastosowanie w branży górnictwa, tj. układy hydrauliczne dostosowane do specyfiki technologii, które one realizują. Wszystkie przedstawione w tym artykule przykłady aplikacji układów hydraulicznych dla konkretnego typu maszyny zostały opracowane przez firmę Bosch Rexroth, ewentualnie powstały przy udziale zaplecza technicznego firmy.