Simulation of the assembly dynamics and control of Space Station Freedom

Robust control design framework for substructure models

“…For the purpose of this study, we dene the process of stiness coupling between the Space Shuttle and station as docking. It should be noted that the coupling process is much more complicated than is assumed in this study, see for example reference [1,2,3]. During docking or joining of structures in space, a signicant problem to be considered is the stabilization of the coupled system before, during, and after the docking of the two systems.…”

“…. ., while the system uncertainty, , consists of individual substructure uncertainties, 1 Figure 7: General Coupled SRCP.…”

“…Figure 8 shows the rst two steps of the design sequence to incorporate both robustness and decentralization of the overall system for a system with two substructures. The rst step involves the design of substructure controller, k 1 , while assuming open loop for substructure 2. At this step, the nominal dynamics of the substructure 2 is included while the component uncertainty and performance for the remaining substructure 2 are ignored.…”

“…gives a smaller region of robustness than controller 4 but is still signicantly larger than controllers 2 and 3. Figure 18 shows the variation in the magnitude of the unweighted frequency response from input r 1 to output e 1 due to a change in interface stiness for = 1, and = ( :4; 0; :4). The open loop frequency response variation of the evaluation model is shown in gure 18(a) for reference.…”