H∞ control in the frequency domain for a semi-active floor isolation system
H∞ control in the frequency domain for a semi-active floor isolation system
Yundong SHI1(), Tracy C BECKER2, Masahiro KURATA2, Masayoshi NAKASHIMA2
1. Graduate School of Engineering, Kyoto University, Kyoto 611-0011, Japan; 2. Disaster Prevention Research Institute, Kyoto University, Kyoto 611-0011, Japan
A floor isolation system installed in a single floor or room in a fixed base structure is designed to protect equipment. With this configuration, the input motions to the floor isolation from the ground motions are filtered by the structure, leaving the majority of the frequency content of the input motion lower than the predominant frequency of the structure. The floor isolation system should minimize the acceleration to protect equipment; however, displacement must also be limited to save floor space, especially with long period motion. Semi-active control with an H∞ control was adopted for the floor isolation system and a new input shaping filter was developed to account for the input motion characteristics and enhance the effectiveness of the H∞ control. A series of shake table tests for a semi-active floor isolation system using rolling pendulum isolators and a magnetic-rheological damper were performed to validate the H∞ control. Passive control using an oil damper was also tested for comparison. The test results show that the H∞ control effectively reduced acceleration for short period motions with frequencies close to the predominant frequency of the structure, as well as effectively reduced displacement for long period motions with frequencies close to the natural frequency of the floor isolation system. The H∞ control algorithm proved to be more advantageous than passive control because of its capacity to adjust control strategies according to the different motion frequency characteristics.
Corresponding Author(s):
SHI Yundong,Email:shiyundong@gmail.com
引用本文:
. H∞ control in the frequency domain for a semi-active floor isolation system[J]. Frontiers of Structural and Civil Engineering, 2013, 7(3): 264-275.
Yundong SHI, Tracy C BECKER, Masahiro KURATA, Masayoshi NAKASHIMA. H∞ control in the frequency domain for a semi-active floor isolation system. Front Struc Civil Eng, 2013, 7(3): 264-275.
floor responsea) under Kobe ground motion, JMA record, EW, 1995
8.8
10.5
SAN_R
floor response under Sannomaru ground motionb)
13.2
2.7
ELC_R
floor response under ELC ground motion
11.2
8.6
ELC
imperial Valley earthquake, 117 El Centro record, EW, 1940
–
2.5
Tab.1
Fig.10
J1/(m·s-2)
J2/mm
J1/(m·s-2)
J2/mm
passive control
H∞, without filter W1
JMA_R
1.88
136
2.07
134
SAN_R
1.90
180
0.65
128
H∞, wf = wpa), c = 0.3
H∞, wf = wp, c = 0.4
JMA_R
0.87
124
1.13
122
SAN_R
0.66
143
0.66
136
ELC_R
0.71
89
0.82
88
ELC
0.55
109
0.62
82
H∞, wf = 13.2 (2.1 Hz), c = 0.3
H∞, wf = 13.2 (2.1 Hz), c = 0.4
JMA_R
1.07
130
1.50
125
Tab.2
Fig.11
Fig.12
Fig.13
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