Regulation of Oscillatory Systems Subjected to Viability ConstraintsK.MuellersauthorRegarding forcing terms of oscillatory systems of second-order differential equations as controls, we look for feedback (set-valued) maps governing the evolution of solutions satisfying viability of state constraints. We give a condition ensuring the existence of minimally forced solutions: the oscillation is unforced as long as viability is not at stake. Finally we compare "minimally forced oscillations" with free oscillations.1994-09WP-94-096Monograph