Active Force Control of Electro-Hydraulic Hybrid Load Simulator using Quantitative Feedback Theory

QFT를 이용한 전기유압 하이브리드 부하 시뮬레이터의 능동 힘제어

  • Yoon, Joo-Hyeon (Department of Mechanical and Automotive Engineering, Univ. of Ulsan) ;
  • Ahn, Kyoung-Kwan (School of Mechanical and Automotive Engineering, Univ. of Ulsan) ;
  • Truong, Dinh Quang (Department of Mechanical and Automotive Engineering, Univ. of Ulsan) ;
  • Jo, Woo-Geun (Department of Mechanical and Automotive Engineering, Univ. of Ulsan)
  • 윤주현 (울산대학교 기계자동차공학과) ;
  • 안경관 (울산대학교 기계자동차공학부) ;
  • 딩쾅청 (울산대학교 기계자동차공학과) ;
  • 조우근 (울산대학교 기계자동차공학과)
  • Published : 2009.02.25


Today, reduction of $CO_2$ exhaustion gas for global-warming prevention becomes important issues in all industrial fields. Hydraulic systems have been widely used in industrial applications due to high power density and so on. However hydraulic pump is always being operated by engine or electric motor in the conventional hydraulic system. Therefore most of the conventional hydraulic system is not efficient system. Recently, an electro-hydraulic hybrid system, which combines electric and hydraulic technology in a compact unit, can be adapted to a wide variety of force, speed and torque requirements. In the electro-hydraulic hybrid system, hydraulic pump is operated by electric motor only when hydraulic power is needed. Therefore the electro-hydraulic system can reduce the energy consumption drastically when compared to the conventional hydraulic systems. This paper presents a new kind of hydraulic load simulator which is composed of electro-hydraulic hybrid system. Disturbances in the real working condition make the control performance decrease or go bad. QFT controller is designed to eliminate or reduce the disturbance and improve the control performance of the electro-hydraulic load simulator. Experimental results show that the proposed controller is verified to apply for electro-hydraulic hybrid system with varied external disturbances.



  1. Rahmfeld, R. and Ivantysynova, M., 'Displacement Controlled Linear Actuator with Differential Cylinder-A Way to Save Primary Energy in Mobile Machines,' Proc. of the 5th Int. Conf. on Fluid Power Transmission and Control, pp. 316-322, 2001
  2. Yao, B., Bu, F., Reedy, J. and Chiu, G., 'Adaptive Robust Motion Control of Single-Rod Hydraulic Actuators: Theory and Experiments,' IEEE/ASME Trans. on Mechatronics, pp. 79-91, 2000
  3. Grabbel, J., 'On the control of joint integrated servo actuators for mobile handling and robotic applications,' Proc. of the 1st FPNI- PhD Symp., pp. 449-465, 2000
  4. Niksefat, N. and Sepehri, N., 'Robust force controller design for a hydraulic actuator based on experimental input-output data,' Proc. of the American Control Conf., pp. 3718-3722, 1999
  5. Thompson, D. F. and Kremer, G. G., 'Quantitative feedback design for a variable displacement hydraulic vane pump,' Proc. of the American Control Conf., pp. 1061-1065, 1997
  6. D'Azzo, J. and Houpis, C. H., 'Linear Control System Analysis and Design,' McGraw-Hill, 1998
  7. Horowitz, I. M., 'Survey of Quantitative Feedback Theory (QFT),' International Journal of Control, Vol. 53, No. 2, pp. 255-291, 1991
  8. Ahn, K. K. and Chau, N. H. T., 'Design of a robust force controller for the new mini motion package using quantitative feedback theory,' Mechatronics, Vol. 17, No. 10, pp. 542-550, 2007
  9. Wu, S. F., Grimble, M. and Breslin, S. G., 'Introduction to Quantitative Feedback Theory for Lateral Robust Flight Control Systems Design,' Control Engineering Practice, Vol. 6, No. 7, pp. 805- 828, 1998