“…Control of oscillatory systems requires achieving nonclassical control goals (swinging, synchronization) as well as describing and analyzing complex motions of the closed loop system. A new approach to stabilization of a desired level of oscillations for Hamiltonian systems based on the speed}gradient method (Fradkov, 1979) and energy objective functions was proposed in Fradkov, (1994Fradkov, ( , 1996, Fradkov, Guzenko, Hill and Pogromsky, (1995) and Fradkov, Makarov, Shiriaev and Tomchina, (1997). Recently, it was extended to a class of nonlinear systems, see Shiriaev, (2000a,b).…”