Design and experimental evaluation of a robust force controller for a 6-link electro-hydraulic manipulator via H∞ control theory

被引:11
作者
KyoungKwan Ahn [1 ]
ByungRyong Lee [1 ]
SoonYong Yang [1 ]
机构
[1] Sch. of Mech. and Automot. Eng., University of Ulsan, Nam-gu, Ulsan 680-764, San 29
来源
KSME International Journal | 2003年 / 17卷 / 7期
关键词
Disturbance Observer; Fluid Power System; H Infinity Control; Hydraulic Manipulators; Impedance Control; Robust Force Control;
D O I
10.1007/BF02982984
中图分类号
学科分类号
摘要
Uninterrupted power supply has become indispensable during the maintenance task of active electric power lines as a result of today's highly information-oriented society and increasing demand of electric utilities. This maintenance task has the risk of electric shock and the danger of falling from high place. Therefore it is necessary to realize an autonomous robot system using electro-hydraulic manipulators because hydraulic manipulators have the advantage of electric insulation and power/mass density. Meanwhile an electro-hydraulic manipulator using hydraulic actuators has many nonlinear elements, and its parameter fluctuations are greater than those of an electrically driven manipulator. So it is relatively difficult to realize not only stable contact work but also accurate force control for the autonomous assembly tasks using hydraulic manipulators. In this paper, the robust force control of a 6-link electro-hydraulic manipulator system used in the real maintenance task of active electric lines is examined in detail. A nominal model for the system is obtained from experimental frequency responses of the system, and the deviation of the manipulator system from the nominal model is derived by a multiplicative uncertainty. Robust disturbance observers for force control are designed using this information in an H∞ framework, and implemented on the two different setups. Experimental results show that highly robust force tracking by a 6-link electro-hydraulic manipulator could be achieved even if the stiffness of environment and the shape of wall change.
引用
收藏
页码:999 / 1010
页数:11
相关论文
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