Open-loop Independent Metering Control of a Multi-DOF Forwarder Boom
Keywords:independent metering, forwarder, energy saving
This study applies independent metering control in a forestry forwarder in order to improve its energy efficiency. The paper describes the control method, which enables smooth control mode switches and relatively accurate velocity tracking without position, velocity or acceleration feedback. The energy saving capability is analysed through measured, realistic, working cycle, which is repeated for the baseline system and independent metering system. The input energy taken by the control valves is compared. Furthermore, the power losses of the supply pump and diesel engine are modelled to achieve semi-empirical estimate for the diesel fuel consumption. The results show an average reduction of 25% in the fuel consumption when compared to the baseline.
Ding, R.; Xu, B.; Zhang, J.; Cheng, M. Bumpless mode switch of independent metering fluid power system for mobile machinery. Automation in Construction 68. 2016, Volume 68, pp. 52–64.
Elfving, M.; Palmberg, J-O.; Jansson, A. Distributed Control of Fluid Power Actuators – A Load Sensing Application of a Cylinder With Decoupled Chamber Pressure Control. Proceedings of the Fifth Scandinavian International Conference on Fluid Power. Linköping, Sweden, 1997.
Eriksson B.; Rösth, M.; Palmberg, J-O. A High Energy Efficient Mobile Fluid Power System – Novel System Layout and Measurements. Proceedings of the 6th International Fluid Power Conference. Dresden, Germany, April 1–2, 2008.
Eriksson B.; Rösth, M.; Palmberg, J-O. Energy saving system utilizing LQ-technique design. Proceedings of the Seventh International Conference on Fluid Power Transmission and Control. Hangzhou, China, 7th–10th April, 2009.
Eriksson, B. Mobile Fluid Power Systems Design with a Focus on Energy Efficiency. Doctoral dissertation, Linköping University, Linköping, Sweden, 2010.
Ge, L.; Dong, Z.; Huang, W.; Quan, L.; Yang, J.; Li, W. Research on the Performance of Hydraulic Excavator with Pump and Valve Combined Separate Meter In and Meter Out Circuits. Proceedings of the IEEE International Conference on Fluid Power Mechatronics, 2015.
Hansen, A.; Pedersen, H.; Andersen, T.; Wachmann, L. Investigation of Energy Saving Separate Meter-in Separate Meter-out Control Strategies. Proceedings of the Twelfth Scandinavian International Conference on Fluid Power. Tampere, Finland, May 18–20, 2011.
Hu, H.; Zhang, Q.; Realization of Programmable Control Using a Set of Individually Controlled Electrohydraulic Valves. Int. J. of Fluid Power. 2002, Volume 3, Issue 2. pp. 29–34.
Huova, M.; Tammisto, J.; Linjama, M.; Tervonen, J. Fuel Efficiency Analysis of Selected Hydraulic Hybrids in a Wheel Loader Application. Proceedings of the 2018 Bath/ASME Symposium on Fluid Power and Motion Control. Bath, UK, September, 12–14.
Jansson, A.; Palmberg, J-O. Separate Controls of Meter-in and Meter-out Orifices in Mobile Hyraulic Systems. SAE Technical Paper 901583. 1990, https://doi.org/10.4271/901583.
Koivumäki, J.; Mattila, J. An energy-efficient high performance motion control of a hydraulic crane applying virtual decomposition control. Proceedings of IEEE/RSJ International Conference on Intelligent Robots and Systems, 2013, pp. 4426–4433.
Mattila, J; Virvalo, T. Energy-efficient Motion Control of a Hydraulic Manipulator. Proceedings of the IEEE International Conference on Robotics & Automation. San Francisco, USA, April 2000.
Nurmi, J; Mattila, J. Global Energy-Optimal Redundancy Resolution of Hydraulic Manipulators: Experimental Results for a Forestry Manipulator. Energies 2017, 10, 647; doi:10.3390/en10050647.
Shenouda, A. Quasi-Static Hydraulic Control Systems and Energy Savings Potential Using Independent Metering Four-Valve Assembly Configuration. Ph.D. Thesis, Woodruff School of Mechanical Engineering, Georgia Institute of Technology. July 5, 2006.
Yao, B.; Liu, S. Energy-Saving Control of Hydraulic Systems With Novel Programmable Valves. Proceedings of the 4th World Congress on Intelligent Control and Automation. Shanghai, China, June 10–14, 2002.
Yuan, Q.; Lew, J. Modelling and Control of Two Stage Twin Spool Servo-Valve for Energy-Saving. Proceedings of the American Control Conference. Portland, OR, USA, June 8–10, 2005.