“…It has been shown that, under some constraints, a chaotic system may be 'controlled': unstable periodic orbits can be stabilized by means of small, periodic perturbations of the system parameters (Ott et al, 1990) or states (Güemez and Matías, 1993;Parthasarathy and Sinha, 1995). In fact, the very nature of chaotic dynamics, with its sensitive dependence on initial conditions and an infinite number of unstable periodic orbits simultaneously embedded in phase space, makes feasible the possibility of chaos control by moving and keeping the system's trajectory close to one of the (unstable) orbits, artificially stabilizing one of them.…”