CONTROL STRUCTURE INTERACTION (CSI): OPTIMIZATION BASED DESIGN TOOLS

MANY ENVISIONED MISSIONS FOR LARGE-SPACE-STRUCTURES (LSS) MUST SATISFY STRINGENT PERFORMANCE DEMANDS, AND HENCE, WILL REQUIRE SOME COMBINATION OF ACTIVE AND PASSIVE CONTROL. IT IS PROPOSED THAT THESE PERFORMANCE REQUIREMENTSMAY BE MORE AFFECTIVELY ACHIEVED BY INTEGRATING THE STRUCTURAL DESIGN WITH THE CONTROL DESIGN TO ACCRUE SIGNIFICANT PERFORMANCE BENEFITS WITH LESS COSTLY CONTROLLERHARDWARE, E.G., ACTUATORS, SENSORS, COMPUTERS, ETC. ONE APPROACH TO THIS PROBLEM INVOLVES INTEGRATING THE STRUCTURAL AND CONTROL DESIGN VIA AN OPTIMIZATION APPROACH. THIS ALLOWS A GREAT DEAL OF FLEXIBILITY IN THE TRADEOFF BETWEEN DESIGN FEATURES, SUCH AS WEIGHT AND POWER REQUIREMENTS, ENTIRELY THROUGH COST FUNCTION SELECTION. THIS APPROACH HAS BEEN USED BEFORE, BUT IN SUCH CASES IT WAS ASSUMED THAT BOTH THE CONTROLLER GAINS AND STRUCTURAL PARAMETERS COULD VARY CONTINUOUSLY OVER SOME SPECIFIED RANGE. THIS APPROACH IS UNREALISTIC SINCE IT IS NOT FEASIBLE FROM EITHER A COST OR A TECHNICAL STANDPOINT TO CONTRUCT A STRUCTURE WHERE EVERY MEMBER IS UNIQUE. IN THIS STUDY, WE PROPOSE TO LIMIT THE STRUCTURAL MEMBERS TO SOME PREDEFINED SET OF AVAILABLE ELEMENTS, AND USE A COMBINATORIAL OPTIMIZATION APPROACH FOR THEIR SELECTION. THIS WILL ALLOW FOR CONTINUOUSLY VARYING CONTROLLER PARAMETERS AND DISCRETLY VARYING STRUCTURAL PARAMETERS, WHILE STILL ACHIEVING AN OPTIMAL DESIGN.