Title :
Frequency-weighting filter selection, for H2 control of microgravity isolation systems: a consideration of the “implicit frequency weighting” problem
Author :
Hampton, R. David ; Whorton, Mark S.
Author_Institution :
Alabama Univ., Huntsville, AL, USA
Abstract :
Many space-science experiments need an active isolation system to provide them with the requisite microgravity environment. The isolation systems planned for use with the International Space Station have been appropriately modeled using relative position, relative velocity, and acceleration states. In theory, frequency-weighting design filters can be applied to these state-space models, in order to develop optimal H 2 or mixed-norm controllers with desired stability and performance characteristics. In practice, however, since there is a kinematic relationship among the various states, any frequency weighting applied to one state will implicitly weight other states. These implicit frequency-weighting effects must be considered for intelligent frequency-weighting filter assignment. The following paper suggests a rational approach to the assignment of frequency-weighting design filters in the presence of kinematic coupling among states, and applies the results to a microgravity vibration isolation problem
Keywords :
H∞ control; aerospace control; aerospace instrumentation; filtering theory; vibration isolation; zero gravity experiments; International Space Station; active vibration isolation; frequency-weighting filter; microgravity system; mixed-norm control; optimal H2 control; space instrumentation; Acceleration; Control systems; Filters; Frequency; Hydrogen; Isolators; Mathematical model; NASA; Payloads; Space technology;
Conference_Titel :
Instrumentation and Measurement Technology Conference, 1999. IMTC/99. Proceedings of the 16th IEEE
Conference_Location :
Venice
Print_ISBN :
0-7803-5276-9
DOI :
10.1109/IMTC.1999.776759