一类新电路系统的奇怪非混沌吸引子分析

Strange Nonchaotic Attractors in a New Circuit System

研究了一类新的概周期驱动电路系统中多种类型的奇怪非混沌吸引子及不同的产生机理.发现了一种新的由T2环面分岔形成的"轮胎形"或"管道形"类奇怪非混沌吸引子,分析了奇怪非混沌吸引子形成的间歇性路线、Heagy-Hammel路线和分形化路线,应用分岔理论和Lyapunov指数方法辨别了由鞍结分岔和亚谐分岔形成的2种不同的间歇性路线,阐释了概周期环面碰撞、环面分形以及吸引子危机等不同奇怪非混沌吸引子的形成机理.

Different mechanism for the creation of strange nonchaotic attractors（SNAs） are studied in a new quasiperiodically forced circuit system. A new mechanism of SNAs-like represented by ＂tire-like＂ and ＂conduit＂ through T2 torus bifurcation is reported. Other prominent routes, namely intermittency, Heagy-Hammel, and fractalization have been identified. The SNAs in this system are created through quasiperiodic saddle-node bifurcation （type-Ⅰ intermittency） as well as through a quasiperiodic subharmonic birucation（type-Ⅲ intermittency）. These routes to strange nonchaos are characterized through the behavior of the largest Lyapunov exponent and bifurcation structure. The formation of SNAs through collision of torus,gradual gractilization of torus and a kind of sudden widening of the attractor is described.