Robust Controller Design For A Constrained Flexible Structure Via Mixed ℓ∞/H∞ Optimization

A successful controller design paradigm must take into account both model uncertainty and performance specifications. Model uncertainty can be addressed using the H∞ robust control framework. However, this framework cannot accommodate the realistic case where in addition to robustness considerations, the system is subject to time domain specifications. We recently proposed a design procedure to explicitly incorporate time-domain specifications into the H∞ framework [1]. In this paper we apply this design procedure to the simple flexible structure used as a benchmark in the 1990-1992 ACC, with the goal of minimizing the peak control effort due to disturbances while satisfying settling time and robustness specifications. The results show that there exist a severe trade-off between peak control action and robustness to unstructured model uncertainty