Engineering topics
Publications and source records attributed to Chiang, R..
This paper presents a vital design concept commonly used in the robust H infinity control synthesis technique - the mixed sensitivity H infinity optimization.
A generalized Popov multiplier theory enables one to analyze system robustness with mixed real/complex parameters, repeated uncertainties, and multidimensional block uncertainties. Using the Cassini spacecraft thrust vector control (TVC) system as a design case study, modern robust control theory has been applied to the real flight project.
The new NASA paradigm calls for more frequent, low-cost, small spacecraft missions capable of returning high-value planetary science. This challenge also extends to the rapid insertion of advanced technologies across all spacecraft subsystems as an enabling tool for building these highly capable miniaturized science platforms in the spirit of.
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This paper summarizes a few years attitude control design work on Cassini spacecraft with emphasis on the mission of Titan flyby. The study consists of modeling of the spacecraft dynamics, fuel sloshing, aerodynamic disturbance, controller design, nonlinear simulation, and establishing geometric command profiles. Both classical bang-bang control and modern robust H-infinity control have been designed and evaluated in nonlinear simulation to access the system tracking performance. Design procedures as well as their critical design issues are discussed in detail. Full model nonlinear simulations indicate that a simple 12-state H-infinity controller achieves better radar tracking performance than the classical bang-bang controller with less fuel throughout the flyby mission. Detailed robustness analysis of both designs will be published elsewhere.