Fault tolerant control allocation in systems with fixed magnitude discrete controls

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dc.contributor.advisor Valasek , John en_US
dc.contributor.committeeMember Datta , A . en_US
dc.creator Marwaha , Monika en_US
dc.date.accessioned 2010 -01 -15T00 :07 :27Z
dc.date.accessioned 2014 -02 -19T19 :34 :17Z
dc.date.available 2010 -01 -15T00 :07 :27Z
dc.date.available 2014 -02 -19T19 :34 :17Z
dc.date.created 2008 -12 en_US
dc.date.issued 2009 -05 -15 en_US
dc.identifier.uri http : / /hdl .handle .net /1969 .1 /ETD -TAMU -3092
dc.description.abstract The promise and potential of controllers that can reconfigure themselves in the case of control effector failures and uncertainties , and yet guarantee stability and provide satisfactory performance , has led to fault tolerant control being an active area of research . This thesis addresses this issue with the design of two fault tolerant nonlinear Structured Adaptive Model Inversion control schemes for systems with fixed magnitude discrete controls . Both methods can be used for proportional as well as discrete controls . However , discrete controls constitute a different class of problems than proportional controls as they can take only binary values , unlike proportional controls which can take many values . Two nonlinear control laws based on Structured Adaptive Model Inversion are developed to tackle the problem of control failure in the presence of plant and operating environment uncertainties . For the case of redundant actuators , these control laws can provide a unique solution . Stability proofs for both methods are derived and are presented in this thesis . Fault Tolerant Structured Adaptive Model Inversion that has already been developed for proportional controls is extended here to discrete controls using pulse width modulation . A second approach developed in this thesis is Fault Tolerant Control Allocation . Discrete control allocation coupled with adaptive control has not been addressed in the literature to date , so Fault Tolerant Control Allocation for discrete controls is integrated with SAMI to produce a system which not only handles discrete control failures , but also accounts for uncertainties in the plant and in the operating environment . Fault tolerant performance of both controllers is evaluated with non real -time nonlinear simulation for a complete Mars entry trajectory tracking scenario , using various combinations of control effector failures . If a fault is detected in the control effectors , the fault tolerant control schemes reconfigure the controls and minimize the impact of control failures or damage on trajectory tracking . The controller tracks the desired trajectory from entry interface to parachute deployment , and has an adaptation mechanism that reduces tracking errors in the presence of uncertainties in environment properties such as atmospheric density , and in vehicle properties such as aerodynamic coefficients and inertia . Results presented in the thesis demonstrate that both control schemes are capable of tracking pre -defined trajectories in the presence of control failures , and uncertainties in system and operating environment parameters , but with different levels of control effort . en_US
dc.format.medium electronic en_US
dc.format.mimetype application /pdf en_US
dc.language.iso en _US en_US
dc.subject Control allocation en_US
dc.title Fault tolerant control allocation in systems with fixed magnitude discrete controls en_US
dc.type Book en
dc.type.genre Electronic Thesis en_US
dc.type.material text en_US
dc.format.digitalOrigin born digital en_US

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Fault tolerant control allocation in systems with fixed magnitude discrete controls. Available electronically from http : / /hdl .handle .net /1969 .1 /ETD -TAMU -3092 .

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