Weight optimization in H∞ loop-shaping control
University of Manchester , UK
DEI - Seminar Room
September 6th, 2011
from 15.00 to 16.00
The H∞ loop-shaping design procedure is an efficient controller synthesis technique that combines classical loop-shaping concepts with H∞ synthesis. This procedure establishes a good tradeoff between robust stability and robust performance of a closed-loop system in a systematic manner. However, the selection of pre- and/or post-compensators, a crucial step in the design procedure, is nontrivial as factors such as RHP poles/zeros of the nominal plant, roll-off rate around crossover frequency, strength of cross-coupling in MIMO systems, expected bandwidth, etc. must be duly considered. In this talk, efficient weight optimization algorithms, formulated in the LMI framework, will be presented. Firstly, a weight optimization framework that incorporates smoothness constraints in order to prevent the cancelation of important modes of the system, for example, lightly-damped poles/zeros of flexible structures, will be discussed. Thereafter, an optimization framework that maximizes the robust performance of a closed-loop system will be presented. The philosophy in the latter approach is in line with practical design objectives, and it gives the best achievable robust performance on a particular problem once a level of robust stability margin is demanded.
Control, automation and measurement