Intelligent Digital Controller Design and Experimental Implementation for a Digital Hydraulic Lifting System
Received: 7 January 2025 | Revised: 2 February 2025 and 9 February 2025 | Accepted: 10 February 2025 | Online: 3 April 2025
Corresponding author: Alaa Jasim Abd
Abstract
This paper examines the enhancement of hydraulic performance through the replacement of a proportional valve with a Digital Valve Unit (DVU) for flow control purposes. The study underscores the significance of proportional hydraulic valves in precise flow regulation, while concurrently acknowledging that efficiencies in flow control may adversely affect the operational efficacy of actuators, particularly in hydraulic lifting systems. The digital valve system uses simple on/off solenoid valves arranged in parallel and integrated with an intelligent controller, designed utilizing a Programmable Logic Controller (PLC) to compete with conventional valves. To this end, both theoretical and experimental evaluations were conducted to compare the performance of the digital and proportional valve systems. The intelligent digital controller operates with discrete flow rates based on geometric sequence, ensuring precise modulation, while the proportional valve uses continuous flow regulation in a closed-loop system. The results revealed that the digital valve system had a 97.8% improvement in energy efficiency, referring to its lower differential pressure. The digital system also exhibited superior linearity and reduced pressure drop at low flow rates; however, its large package size posed a challenge. The proposed configuration was tested through simulations and practical implementation with the PLC, demonstrating its flexibility in adapting to various flow control needs in hydraulic lifting systems. In conclusion, the Digital Hydraulic System (DHS) offers a promising solution for meter-in flow control, providing enhanced performance in hydraulic applications.
Keywords:
Digital Valve Unit (DVU), proportional valve, PLC, proximity sensor, meter-in controlDownloads
References
L. A. K. Kumar, V. I. Indragandhi, and U. Y. Maheswari, Software Tools for the Simulation of Electrical Systems: Theory and Practice, 1st edition. London San Diego Cambridge Oxford: Academic Press, 2020.
F. M. Linjama, A. Laamanen, and M. Vilenius, "Is it time for digital hydraulics?," in The Eighth Scandinavian International Conference on Fluid Power, Tampere, Finland, 2003.
D. N. Johnston and K. A. Edge, "The Efficiency of Hydraulic Valve-Controlled Systems: A Theoretical and Experimental Analysis," in Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering, 2012, vol. 226, pp. 1045–1056.
M. Linjama, "Digital Fluid Power – State of the Art," in The Twelfth Scandinavian International Conference on Fluid Power, Tampere, Finland, 2011.
M. Linjama, E. Lantto, and M. Vilenius, "Energy-efficient control of digital hydraulic valves," Journal of Power Sources, vol. 234, pp. 255–263, 2013.
I. H. A. Al-Hady, F. M. Mohammed, and J. A.-K. Mohammed, "A review on the employment of the hydraulic cylinder for lifting purposes," Indonesian Journal of Electrical Engineering and Computer Science, vol. 28, no. 3, pp. 1475–1485, Dec. 2022.
L. Siivonen, M. Linjama, M. Huova, and M. Vilenius, "Jammed on/off Valve Fault Compensation with Distributed Digital Valve System," International Journal of Fluid Power, vol. 10, no. 2, pp. 73–82, Jan. 2009.
P. Achten, M. Linjama, R. Scheidl, and S. Schmidt, "Discussion: Is the future of fluid power digital?," Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering, vol. 226, no. 6, pp. 724–727, Jul. 2012.
M. Linjama, K. T. Koskinen, and M. Vilenius, "Accurate Trajectory Tracking Control of Water Hydraulic Cylinder with Non-Ideal on/off Valves," International Journal of Fluid Power, vol. 4, no. 1, pp. 7–16, Jan. 2003.
M. Linjama and K. Huhtala, "Digital hydraulic power management system - towards lossless hydraulics," in Proceedings of the Third Workshop on Digital Fluid Power, Tampere, Finland, 2010, pp. 5–22.
A. Brorsen, "Feasibility study of a novel ON/OFF valve solution for velocity servo systems," M.S. thesis, Department of Energy Technology, Aalborg University, Aalborg, Denmark, 2014.
F. Sciatti, P. Tamburrano, E. Distaso, and R. Amirante, "Digital Hydraulic Technology: Applications, Challenges, and Future Direction," Journal of Physics: Conference Series, vol. 2648, no. 1, Dec. 2023, Art. no. 012053.
B. Winkler, A. Plockinger, and R. Scheidl, "State of the art in digital valve technology," in The Seventh Workshop on Digital Fluid Power, Linz, Austria, 2015.
Q. Zhang, X. Kong, B. Yu, K. Ba, Z. Jin, and Y. Kang, "Review and Development Trend of Digital Hydraulic Technology," Applied Sciences, vol. 10, no. 2, Jan. 2020, Art. no. 579.
M. Gao, Q. Wang, X. Shan, Q. Li, and L. Zhang, "Application of Hydraulic Energy-Saving Technology in the Teaching, Research, and Practice of Mechanical Engineering," Sustainability, vol. 16, no. 3, Jan. 2024, Art. no. 1315.
F. V. Hrib, A. I. Iancu, and C. C. Dosoftei, "Digital Twin and Virtual Reality: A Co-simulation Environment for an Educational Hydraulic Workstation," in 2024 International Conference on Development and Application Systems (DAS), Suceava, Romania, May 2024, pp. 42–47.
P. M. Bhagwat, A. Ingale, M. Jagtap, S. Chougule, A. Banhatti, and S. Mangave, "Enhancing Hydraulic System Performance through Intelligent Control and Energy Efficiency," Asian Review of Mechanical Engineering, vol. 13, no. 1, pp. 17–26, Apr. 2024.
I. Hyoty, "Commercial high flow on/off-valves for digital hydraulics," in The Fifth Workshop on Digital Fluid Power, Tampere, Finland, 2012.
A. Parr, Hydraulics and Pneumatics: A Technician’s and Engineer’s Guide, 3rd edition. Amsterdam Boston: Butterworth-Heinemann, 2011.
S. S. Khaleel, M. Y. Salloom, and A. Z. Mohammed, "Comparison Sequences of Pick and Place System Controlled Using PLC," Al-Nahrain Journal for Engineering Sciences, vol. 23, no. 4, pp. 397–407, Dec. 2020.
M. Y. Sallom and R. N. Khaleel, "Stabilizing Gap of Pole Electric Arc Furnace Using Smart Hydraulic System," Al-Khwarizmi Engineering Journal, vol. 11, no. 1, pp. 11–18, Feb. 2015.
M. Y. Salloom and M. Y. Almuhanna, "Analysis of the Improved Proportional Hydraulic Directional Control Valve by Adding a Solenoid Directional Valve," Journal Européen des Systèmes Automatisés, vol. 57, no. 1, pp. 105–115, Feb. 2024.
S. S. Khaleel, M. Y. Salloom, and A. M. Shammari, "Arduino-Based Controller for Sequence Development of Automated Manufacturing System," Al-Khwarizmi Engineering Journal, vol. 16, no. 3, pp. 22–33, Sep. 2020.
D. Gravitz, "HydroCom - A high quality solution for three diver communications," in OCEANS ’85 - Ocean Engineering and the Environment, San Diego, CA, USA, Nov. 1985, pp. 1306–1310.
I. L. Krivts and G. V. Krejnin, Pneumatic Actuating Systems for Automatic Equipment: Structure and Design, 1st edition. Boca Raton, Fl, USA: CRC Press, 2006.
A. Morad, "Proportional Hydraulic Control System of Overrunning Variable Load Actuator," International Research Journal of Engineering and Technology (IRJET), vol. 03, no. 05, pp. 85–94, May 2016.
H. H. Hadi and M. Y. Salloom, "Pneumatic control system of automatic production line using two methods of SCADA/HMI implement PLC," Al-Khwarizmi Engineering Journal, vol. 15, no. 3, pp. 16–28, Sep. 2019.
E. Elsaed, M. Abdelaziz, and N. Mahmoud, "Investigation of a digital valve system efficiency for metering-in speed control using MATLAB/Simulink," in Proceedings of 2017 International Conference on Hydraulics and Pneumatics - HERVEX, Baile Govora, Romania, 2017.
P. Tamburrano, P. D. Palma, A. R. Plummer, E. Distaso, F. Sciatti, and R. Amirante, "Simulation of a high frequency on/off valve actuated by a piezo-ring stack for digital hydraulics," E3S Web of Conferences, vol. 312, 2021, Art. no. 05008.
S. M. Rashid, M. Y. Salloom, N. H. B. Jemily, and A.-S. H, "Modeling and Simulation of Hydraulic Proportional Control Valves with Different Types of Controllers," Al-Khwarizmi Engineering Journal, vol. 20, no. 2, pp. 56–64, Jun. 2024.
A. Laamanen, L. Siivonen, M. Linjama, and M. Vilenius, "Digital flow control unit-an alternative for a proportional valve?," in Bath Workshop on Power Transmission and Motion Control (PTMC 2004), 2004, pp. 297–308.
A. F. Ozalp, R. Polat, C. Cetinkaya, and M. H. Cetin, "Investigation of a Digital Hydraulic Valve Operated by Servo Motors," Engineering, Technology & Applied Science Research, vol. 11, no. 6, pp. 7957–7963, Dec. 2021.
A. Laamanen, M. Linjama, and M. Vilenius, "Pressure peak phenomenon in digital hydraulic systems - a theoretical study," in Bath Workshop on Power Transmission and Motion Control (PTMC 2005), 2005, pp. 91–104.
M. Linjama and M. Vilenius, "Digital hydraulic control of a mobile machine joint actuator mockup," in Bath Workshop on Power Transmission and Motion Control (PTMC 2004), 2004, pp. 145–158.
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