“A Novel Control Design for Realizing Passive Load-Holding Function on a Two-Motor-Two-Pump Motor-Controlled Hydraulic Cylinder”

Authors: Wei Zhao, Mohit Bhola, Morten K. Ebbesen and Torben Ole Andersen,
Affiliation: University of Agder and Aalborg University
Reference: 2023, Vol 44, No 3, pp. 125-139.

Keywords: Motor-controlled hydraulic cylinder, pressure control, load-holding

Abstract: When a hydraulic cylinder connects two chambers directly to one or two hydraulic pumps driven by electric servo motors without any control valve in between, it can be called a motor-controlled hydraulic cylinder (MCC). Unlike valve-controlled cylinders, MCCs have no valve throttling, which significantly increases the energy efficiency. Among different MCC topologies, the two-motor-two-pump (2M2P) MCC has several advantages, such as cylinder pressure control and no mode switch oscillations. However, due to state coupling when controlling both piston position and minimum cylinder chamber pressure, the 2M2P MCC is a multi-input-multi-output (MIMO) system that usually requires advanced MIMO controller analysis and design. This paper presents a control algorithm for a 2M2P MCC with the minimum cylinder pressure control and passive load-holding function. This control algorithm is tested on a single-boom crane characterized by overrunning loads. It is designed based on the analysis of the system characteristics, requiring no MIMO controller analysis and design. A non-linear model of a single-boom crane driven by the proposed 2M2P MCC is created in MATLAB/Simulink and experimentally validated. Feedback controllers are designed and verified via simulations to realize position control, minimum cylinder pressure control, and load-holding under standstill command. For a given load and speed profile, the hydraulic system efficiency during pumping and motoring mode is 55-60% and 20-25%, respectively. The system's overall efficiency can be enhanced with electrical regenerative drives, which feeds the generated power from potential energy to the grid or battery and reused in the next working cycle. The experimental results presented in this paper verifies the efficacy of the proposed control algorithm and demonstrates its superior performance in achieving the desired system response under various operating conditions.

PDF PDF (2568 Kb)        DOI: 10.4173/mic.2023.3.3

DOI forward links to this article:
[1] Wei Zhao, Morten Kjeld Ebbesen and Torben Ole Andersen (2023), doi:10.1109/ICCMA59762.2023.10374706
[2] Wei Zhao, Morten Kjeld Ebbesen, Michael Rygaard Hansen and Torben Ole Andersen (2024), doi:10.3390/en17112484
[1] Agostini, T., DeNegri, V., Minav, T., and Pietola, M. (2020). Effect of energy recovery on efficiency in electro-hydrostatic closed system for differential actuator, In Actuators, 1. MDPI, page12.
[2] Fresia, P., Rundo, M., Padovani, D., and Altare, G. (2022). Combined speed control and centralized power supply for hybrid energy-efficient mobile hydraulics, Automation in Construction. 140:104337.
[3] Hagen, D. and Padovani, D. (2020). A method for smoothly disengaging the load-holding valves of energy-efficient electro-hydraulic systems, In Proceedings of the First International Electronic Conference on Actuator Technology: Materials, Devices and Applications. Online.
[4] Hagen, D., Padovani, D., and Choux, M. (2019). A comparison study of a novel self-contained electro-hydraulic cylinder versus a conventional valve-controlled actuator-part 2: Energy efficiency, Actuators. 8. doi:10.3390/ACT8040078
[5] Hagen, D., Padovani, D., and Choux, M. (2020). Guidelines to select between self-contained electro-hydraulic and electro-mechanical cylinders, In 2020 15th IEEE Conference on Industrial Electronics and Applications (ICIEA). IEEE, pages 547--554.
[6] Hagen, D., Padovani, D., and Ebbesen, M.K. (2018). Study of a self-contained electro-hydraulic cylinder drive, In 2018 Global Fluid Power Society PhD Symposium (GFPS). IEEE, pages 1--7.
[7] Hansen, A.H. (2023). Fluid Power Systems -- A Lecture Note in Modelling, Analysis and Control, Springer Nature Switzerland AG.
[8] Imam, A., Rafiq, M., Jalayeri, E., and Sepehri, N. (2017). Design, implementation and evaluation of a pump-controlled circuit for single rod actuators, Actuators. 6:10--16. doi:10.3390/act6010010
[9] Jalayeri, E., Imam, A., Tomas, Z., and Sepehri, N. (2015). A throttle-less single-rod hydraulic cylinder positioning system: Design and experimental evaluation, Advances in Mechanical Engineering. 7(5):1687814015583249.
[10] Jensen, K.J., Ebbesen, M.K., and Hansen, M.R. (2021). Novel concept for electro-hydrostatic actuators for motion control of hydraulic manipulators, Energies. 14. doi:10.3390/en14206566
[11] Ketelsen, S., Andersen, T.O., Ebbesen, M.K., and Schmidt, L. (2020). A self-contained cylinder drive with indirectly controlled hydraulic lock, Modeling, Identification and Control: A Norwegian Research Bulletin. 41:185--205. doi:10.4173/mic.2020.3.4
[12] Ketelsen, S., Schmidt, L., Donkov, V.H., and Andersen, T.O. (2018). Energy saving potential in knuckle boom cranes using a novel pump controlled cylinder drive, Modeling, Identification and Control (Online). 39(2):73--89.
[13] Kjelland, M. and Hansen, M. (2015). Offshore wind payload transfer using flexible mobile crane, Modeling, Identification and Control. 36:1--9. doi:10.4173/mic.2015.1.1
[14] Padovani, D., Ketelsen, S., Hagen, D., and Schmidt, L. (2019). A self-contained electro-hydraulic cylinder with passive load-holding capability, Energies. 12. doi:10.3390/en12020292
[15] Parker, H. (0). Electro-hydraulic actuators for high power density applications, [EB.
[16] Qu, S., Fassbender, D., Vacca, A., and Busquets, E. (2020). A high-efficient solution for electro-hydraulic actuators with energy regeneration capability, Energy. page 119291. https://doi.org/10.1016/j.energy.2020.119291, doi:10.1016/j.energy.2020.119291
[17] Quan, Z., Quan, L., and Zhang, J. (2014). Review of energy efficient direct pump controlled cylinder electro-hydraulic technology, Renewable and Sustainable Energy Reviews. 35:336--346.
[18] Schmidt, L., Ketelsen, S., Brask, M.H., and Mortensen, K.A. (2019). A class of energy efficient self-contained electro-hydraulic drives with self-locking capability, Energies. 12(10):1866.
[19] SweeneyT., A.D., KubinskiP.T. (2012). Electro-hydraulic actuator mounting, U.S. Patent 8161742 B2.
[20] Sørensen, J.K., Hansen, M.R., and Ebbesen, M.K. (2016). Numerical and experimental study of a novel concept for hydraulically controlled negative loads, Modeling, Identification and Control. 37:195--211. doi:10.4173/mic.2016.4.1
[21] Zhang, S., Minav, T., and Pietola, M. (2017). Decentralized hydraulics for micro excavator, In Proceedings of 15th Scandinavian International Conference on Fluid Power. Linkoping, Sweden, pages 187--195.
[22] Zhao, W. and Bhola, M. (2023). Comparing compact and remote deployments of a speed-controlled cylinder drive unit on an offshore knuckle boom crane, In Proceedings of the 18th Scandinavian International Conference on Fluid Power (accepted). Tampere, Finland.
[23] Zhao, W., Ebbesen, M.K., and Andersen, T.O. (2022). Identifying the future research trend for using speed-controlled hydraulic cylinders in offshore applications through literature survey, In Proceedings of 2022 IEEE Global Fluid Power Society PhD Symposium (presented). Naples, Italy.
[24] Zimmerman, J.D., Pelosi, M., Williamson, C.A., and Ivantysynova, M. (2007). Energy consumption of an ls excavator hydraulic system, In Proceedings of ASME 2007 International Mechanical Engineering Congress and Exposition. Seattle, Washington, USA, pages 117--126.

  title={{A Novel Control Design for Realizing Passive Load-Holding Function on a Two-Motor-Two-Pump Motor-Controlled Hydraulic Cylinder}},
  author={Zhao, Wei and Bhola, Mohit and Ebbesen, Morten K. and Andersen, Torben Ole},
  journal={Modeling, Identification and Control},
  publisher={Norwegian Society of Automatic Control}