Studies of hydraulic drive efficiency with discrete valve and switched inertia tube
Dynamics, strength of machines, instruments and equipment
Аuthors*, **, ***
Samara National Research University named after Academician S.P. Korolev, 34, Moskovskoye shosse, Samara, 443086, Russia
For the last years, energy efficiency is one of the main and important issues in developing fluid power technology. The discrete method of regulation is of particular interest while the development of such systems, in which the fluid stream is alternately supplied to the hydraulic drive actuator. For this purpose, discrete action valves are used. They are relatively simple, reliable, insensitive to contamination, and possess low cost.
The paper presents the mathematical model of the hydraulic drive for loads lifting, containing discrete valve and switched inertia tube. Employing a switched inertia device (inertia tube and discrete valve) in the hydraulic drive system allows increase efficiency of such system by 20-30% due to the inflow of additional liquid from the low-pressure line (so-called flow amplifier mode).
As a result of dynamic processes simulation in MATLAB/Simulink package, transients occurring while hydraulic drive operation were calculated. The article analyzes the effect of the following parameters on the hydraulic drive efficiency: the discrete valve operation frequency in the pressure line, the pulse duty cycle, the diameter and length of the inertia tube. Regulation quality estimation is given in the movement of the output link of the hydraulic drive with a cargo on the set trajectory.
It was established that for the hydraulic drive with the pressure in the pressure line of 15 MPa and a weight of the cargo up to 1000 kg, the use of a hydraulic drive scheme with discrete valve and switched inertia tube allows increase its efficiency by 17% compared to the throttle control. The recommended parameters for such system configuration are as follows: the discrete valve operating frequency is 40 Hz, the pulse duty cycle is 30 to 50%, the inertial tube diameter is 10 mm, its length is no more than 10 m. The diameter of the discrete valve hole in the pressure line should be sel ected fr om conditions for ensuring the required speed of the output link.
The disadvantage is acoustic noise while using a switched inertia device. It is necessary to use a pulsation damper to eliminate it.
The obtained results can be useful for selecting hydraulic drive schemes with a higher coefficient of energy efficiency.
Keywords:discrete hydraulic drive, electrohydraulic valve, pulse ratio, duty cycle, inertia tube, mathematical model, efficiency
Brown F.T. Switched reactance hydraulics, a new way to control fluid power, National Conference on Fluid Power, Chicago, USA, 1987, pp. 25-34.
Brown F.T., Tentarelli S.C., Ramachandran S.A. Hydraulic Rotary Switched-Inertance Servo-Transformer, Journal of Dynamic Systems Measurement and Control-Transactions of the AMSE, 1988, vol. 110, pp. 144-150.
Gall H., Senn K. Ansteuerungskonzept zur Energieeinsparung bei hydraulischen Linearantrieben, Freilauf Ventile. Olhydraulik und Pneumatik, 1994, no. 38, pp. 38-43.
Scheidl R., Schindler D., Riha G. et al. Basics for the Energy-Efficient Control of Hydraulics Drives by Switching Techniques, Proc. 3rd Conference on Mechatronics and Robotics, Stuttgart, 1995, pp.118-131.
Linjama M. Energy Saving Digital Hydraulics, The Second Workshop on Digital Fluid Power, 12-13 November 2009, Linz, Austria, pp. 5–20.
Johnston D.N. A Switched Inertance Device for Efficient Control of Pressure and Flow, Dynamic Systems and Control Conference, Hollywood, California, USA, 2009, pp.1-8
Pan M., Johnston D.N., Hillis A. Active Control of Pressure Pulsation in a Switched Inertance Hydraulic Systems Using a Rectangular-Wave Reference Signal, Proc. Fluid Power and Motion Control Symposium (FPMC 2012), Bath, UK, 2012, pp. 165-177.
Kogler H., Manhartsgruber B. Simulation tools and control design for fast switching hydraulic systems, The Second Workshop on Digital Fluid Power, 12-13 November 2009, Linz, Austria, pp. 85-93.
Kogler H., Scheidl R., Ehrentraut M., Guglielmino E., Semini C., Caldwell D.G. A Compact Hydraulic Switching Converter for Robotic Applications, Proc. Fluid Power and Motion Control Symposium (FPMC 2010), Bath, UK, 2010, pp. 56-68.
Shakhmatov E.V., Gimadiev A.G., Sverbilov V.Ya., Sinyakov A.F. Vestnik Samarskogo universiteta. Aerokosmicheskaya tekhnika, tekhnologii i mashinostroenie, 2013, no. 1 (39), pp. 157-167.
Shorin V.P., Sverbilov V.Ya., Gimadiev A.G., Greshnyakov P.I., Ilyukhin V.N., Stadnik D.M. Vestnik Samarskogo universiteta. Aerokosmicheskaya tekhnika, tekhnologii i mashinostroenie, 2013, no. 1 (39), pp. 168-177.
Shakhmatov E.V., Sverbilov V.Ya., Gimadiev A.G., Sinyakov A.F. Patent RF na poleznuyu model’ № 152072, 04.12.2012.
D’yakonov V.P. Simulink 5/6/7 (Simulink 5/6/7), Moscow, DMK-Press, 2008, 784 p.
- Kuznetsov E.A., Sysoev O.E., Kolykhalov D.G. Trudy MAI, 2016, no. 88, available at: http://trudymai.ru/eng/published.php?ID=70409