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Multivariable control of the Space Shuttle remote manipulator system using H2 and H(infinity) optimizationThree linear controllers are desiged to regulate the end effector of the Space Shuttle Remote Manipulator System (SRMS) operating in Position Hold Mode. In this mode of operation, jet firings of the Orbiter can be treated as disturbances while the controller tries to keep the end effector stationary in an orbiter-fixed reference frame. The three design techniques used include: the Linear Quadratic Regulator (LQR), H2 optimization, and H-infinity optimization. The nonlinear SRMS is linearized by modelling the effects of the significant nonlinearities as uncertain parameters. Each regulator design is evaluated for robust stability in light of the parametric uncertanties using both the small gain theorem with an H-infinity norm and the less conservative micro-analysis test. All three regulator designs offer significant improvement over the current system on the nominal plant. Unfortunately, even after dropping performance requirements and designing exclusively for robust stability, robust stability cannot be achieved. The SRMS suffers from lightly damped poles with real parametric uncertainties. Such a system renders the micro-analysis test, which allows for complex peturbations, too conservative.
Document ID
19910018226
Acquisition Source
Legacy CDMS
Document Type
Thesis/Dissertation
Authors
Prakash, OM, II
(Draper (Charles Stark) Lab., Inc. Cambridge, MA, United States)
Date Acquired
September 6, 2013
Publication Date
May 1, 1991
Subject Category
Mechanical Engineering
Report/Patent Number
NAS 1.26:185661
CSDL-T-1083
AD-A243671
NASA-CR-185661
Accession Number
91N27540
Funding Number(s)
PROJECT: RTOP 551-15-00
CONTRACT_GRANT: NAS9-18147
Distribution Limits
Public
Copyright
Public Use Permitted.
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