Discrete-time mixed-normH2/H∞ controller synthesis

Abstract

H2/H∞ optimal control synthesis enables the design of controllers for simultaneous rejection of both narrow-band and wide-band disturbances and also has applications in robust control. Synthesis equations in the form of coupled Riccati and Lyapunov equations are available for both full-order and reduced-order, continuous-time H2/H∞ control design and it is possible to base numerical algorithms on these synthesis equations. However, currently it has not been found feasible to develop such synthesis equations for the equivalent discrete-time problems. This highlights the necessity of parameter optimization approaches to the design of discrete-time H2/H∞ controllers. This paper considers H2/H∞ discrete-time controller design and develops a solution approach that relies on continuation algorithms. The results are illustrated using a benchmark non-collocated flexible structure example.