Lower bounds in multi-objective H/sub 2//H/sub /spl infin// problems

In this paper we discuss a multiobjective control problem that involves several H/sub 2/-norm and H/sub /spl infin//-norm constraints. In an accompanying paper we show how to efficiently compute a sequence of upper bounds that converges monotonically from above to the optimal value of such problems. If more than one H/sub /spl infin// constraint is involved, it is shown how to compute as well a sequence of lower bounds that converges to the optimum. This complements the tools available for multiobjective LMI based control by a stopping criterion.