A system governed by a set of nonautonomous differential equations with robust strange nonchaotic attractor of Hunt and Ott type

A physically realizable nonautonomous system of ring structure is considered, which manifests a robust strange nonchaotic attractor (SNA), similar to the attractor in the map on a torus proposed earlier by Hunt and Ott. Numerical simulation of the dynamics for the corresponding non-autonomous set of differential equations with quasi-periodic coefficients is provided. It is demonstrated that in terms of appropriately chosen phase variables the dynamics is consistent with the topology of the mapping of Hunt and Ott on the characteristic period. It has been shown that the occurrence of SNA agrees with the criterion of Pikovsky and Feudel. Also, the computations confirm that the Fourier spectrum in sustained SNA mode is of intermediate class between the continuous and discrete spectra (the singular continuous spectrum).