ROBUST ADAPTIVE CONTROL OF LARGE SPACE STRUCTURES

THE OBJECTIVE OF THE PRESENT PROPOSAL IS THE DEVELOPMENT OF EFFICIENT TECHNIQUES FOR SYSTEM IDENTIFICATION AND ADAPTIVE CONTROL OF LARGE SPACE STRUCTURES (LSS). MANY OF THE ENVISIONED FUTURE SPACE MISSIONS WILL IMPOSE STRINGENT PERFORMANCE DEMANDS ON TRACKING ACCURACY, RESPONSE TIME, ANDACTIVE SUPRESSION OF STRUCTURAL VIBRATIONS OF SUCH STRUCTURES. THESE GOALS CAN ONLY BE ACHIEVED THROUGH THE USE OF A ROBUST CONTROL DESIGN BASED UPON ON-BOARD SYSTEM IDENTIFICATION, HENCE, AN ADAPTIVE CONTROL STRATEGY. THE PROPOSED ADAPTIVE SCHEME IS QUITE DIFFERENT FROM THE CONVENTIONAL ADAPTIVE SCHEMES, IN THAT THE IDENTIFICATION PROCESS PROVIDE INFORMATION ABOUT MODELING UNCERTAINTY IN THE FORMAT THAT IS ANTICIPATED BY THE ROBUST CONTROL DESIGN RULE. WITH SUCH AN ESTIMATE IN HAND, THE CONTROLLER CAN BE REDESIGNED TO PROVIDE ROBUSTNESS WITH RESPECT TO MODEL UNCERTAINTY. IN THIS PROPOSED STUDY WE WILL ADDRESS THE FEASIBILITY OF PERFORMING ON-BOARD PLANT UNCERTAINTY ESTIMATION AND ROBUST CONTROL DESIGN BY USING ON-LINE INPUT-OUTPUT DATA. ON-BOARDUNCERTAINTY ESTIMATION WILL BE DEVELOPED FOR PARAMETER UNCERTAINTY AND UNMODELED DYNAMICS. ON-BOARD ROBUST CONTROLDESIGN METHODS, CAPABLE OF HANDLING PARAMETER UNCERTAINTY AND UNMODELED DYNAMICS, WILL ALSO BE STUDIED. THE PROPOSED ADAPTIVE SCHEME WILL BE TESTED ON A SIMULATION MODEL OF A REPRESENTATIVE LSS SYSTEM.