Flow matching with combined control of the pump and the valves for the independent metering swing system of a hydraulic excavator

Abstract

Because of the throttling loss of the control valves and the overflow loss in the frequently accelerating and decelerating motion with a large inertia, the swing system of a hydraulic excavator has a high energy consumption; also, it has a poor controllability. To solve these problems, this paper proposes flow matching with combined control of the pump and the valves and an independent metering method for the swing system of the hydraulic excavator. The inlet pressure and the outlet pressure of the hydraulic motor can be controlled independently. With combined control of the pump and the valves, the flow rate can match the rotational speed of the hydraulic motor so that the overflow loss is avoided. Furthermore, we also develop a simulation model consisting of the mechanical structure of the hydraulic excavator with multi-body dynamics and an electrohydraulic system for analysing the feasibility of this swing system, and the simulation results demonstrate that this system works smoothly. After using the presented control strategies, the results of experiments show that the energy efficiency is improved and that the system can reduce the throttling loss and can obviously suppress the swing vibrations.

Keywords

Swing system of a hydraulic excavator energy efficiency combined pump and valves flow matching separate meter-in and meter-out systems

Get full access to this article

View all access options for this article.

References

Haga

Hiroshi

Fujishima

Digging control system for hydraulic excavator. Mechatronics 2001; 11(6): 665–676.

Chacko

Cang

Vladareaunu

. State of the art in excavators. In: 2014 international conference on advanced mechatronic systems, Kumamoto, Japan, 10–12 August 2014, pp. 481–488. New York: IEEE.

Kagoshima

Komiyama

Nanjo

Tsutsui

Development of new hybrid excavator. Kobelco Technol Rev 2007; 27: 39–42.

Jiang

et al . Research on hydraulic excavator’s energy saving based on energy recovery and reuse. Fluid Power Transmission Control 2011; 6: 7–10.

Yao

Zhang

Koehler

Litherland

. High performance swing velocity tracking control of hydraulic excavators. In: 1998 American control conference, Philadelphia, Pennsylvania, USA, 26 June 1998, Vol 2, pp. 818–822. New York: IEEE.

Busquets

Ivantysynova

. A robust multi-input multi-output control strategy for the secondary controlled hydraulic hybrid swing of a compact excavator with variable accumulator pressure. In: ASME/BATH 2014 symposium on fluid power and motion control, Bath, UK, 10–12 September 2014, paper FPMC2014-7859, pp. 1–9. New York: ASME.

Jin

Park

Lee

A control method to suppress the swing vibration of a hybrid excavator using sliding mode approach. Proc IMechE Part C: J Mechanical Engineering Science 2012; 226(5): 1237–1253.

Wang

Quan

Methods of restrain the hydraulic impact with active adjusting the variable damping in system with large inertia load. J Mech Engng 2014; 50(8): 182–188.

Pettersson

Tikkanen

. Secondary control in construction machinery: design and evaluation of an excavator swing drive. In: 11th Scandinavian international conference on fluid power, Linköping, Sweden, 2–4 June 2009, pp. 56–65. Linköping: Linköping University.

10.

Yoo

Park

Kim

. Design and control of hybrid electric power system for a hydraulically actuated excavator. SAE paper 2009-01-2927, 2009.

11.

Guan

Lin

Recovering system of swing braking energy in hydraulic excavator. J Zhejiang Univ (Engng Sci) 2012; 46(1): 142–149.

12.

Wang

QF.

Research on electro-hydraulic meter-in and meter-out independent regulation system. China Mech Engng 1999; 10(8): 853–855.

13.

Nielsen

BK.

Controller development for a separate meter-in separate meter-out fluid power valve for mobile applications. PhD Thesis, Institute of Energy Technology, Aalborg University, Aalborg, Denmark, 2005.

14.

Shenouda

Quasi-static hydraulic control systems and energy savings potential using independent metering four-valve assembly configuration. PhD Thesis, Georgia Institute of Technology, Atlanta, Georgia, USA, 2006.

15.

Quan

Lian

ZS.

Improving the efficiency of pump controlled differential cylinder system with inlet and outlet separately controlled principle. J Mech Engng 2005; 41(3): 123–127.

16.

Eriksson

Mobile fluid power systems design: with a focus on energy efficiency. PhD Thesis, Linköping University, Linköping, Sweden, 2010.

17.

Meyer

Weiler

Murrenhoff

. Optimal nominal pressurization generation: a novel idea for a discrete logic control using an independent metering valve configuration. In: ASME 2011 dynamic systems and control conference and Bath/ASME symposium on fluid power and motion control, Arlington, Virginia, USA, 31 October–2 November 2011, Vol 2, paper DSCC2011-5947, pp. 351–354. New York: ASME.

18.

Choi

Seo

Nam

Kim

KU.

Energy-saving in excavators with application of independent metering valve. J Mech Sci Technol 2015; 29(1): 387–395.

19.

Quan

Feng

Chen

Independent metering control electro-hydraulic system with pump and valve combined and flow matching. China, Patent ZL200710062517.3, 23 January 2008.