多卷波混沌吸引子

✍ dations ◷ 2024-12-23 09:25:28 #非线性常微分方程,混沌理论

多卷波混沌吸引子(N scroll chaotic attractor)也称N卷波吸引子,是实际混沌电路(一般而言,是蔡氏电路)加上一个非线性电阻(例如蔡氏二极管(英语:Chua's Diode))而产生的奇异吸引子。多卷波混沌吸引子可以用三个非线性常微分方程以及三段的片段连续线性方程来描述。这可以简化系统的数值模拟,也因为蔡氏电路的简易设计单,也很容易实作。

多卷波混沌吸引子在保密数码通讯,同步预测等方面有重要应用。

陈氏系统: d x ( t ) d t = a ( y ( t ) x ( t ) ) , {\displaystyle {\frac {\mathrm {d} x(t)}{\mathrm {d} t}}=a*(y(t)-x(t)),}

d y ( t ) d t = ( c a ) x ( t ) x ( t ) f + c y ( t ) , {\displaystyle {\frac {\mathrm {d} y(t)}{\mathrm {d} t}}=(c-a)*x(t)-x(t)*f+c*y(t),}

d z ( t ) d t = x ( t ) y ( t ) b z ( t ) {\displaystyle {\frac {\mathrm {d} z(t)}{\mathrm {d} t}}=x(t)*y(t)-b*z(t)}

其中 f {\displaystyle f} 为调控函数:

51 frame N scroll modified Chen attractor.gif

f = g z ( t ) h sin ( z ( t ) ) {\displaystyle f=g*z(t)-h*\sin(z(t))}

参数:

:= a = 35, c = 28, b = 3, g = 1, h = -25..25;

初始条件:

initv := x(0) = 1, y(0) = 1, z(0) = 14;

利用Maple中龙格-库塔-菲尔伯格法(英语:Runge–Kutta–Fehlberg method)(Runge–Kutta–Fehlberg法,简称 RKF45)可得数字解并做图。

f = d 0 z ( t ) + d 1 z ( t τ ) d 2 sin ( z ( t τ ) ) {\displaystyle f=d0*z(t)+d1*z(t-\tau )-d2*\sin(z(t-\tau ))}

参数:

params := a = 35, c = 28, b = 3, d0 = 1, d1 = 1, d2 = -20..20, tau = .2;

初始条件:

initv := x(0) = 1, y(0) = 1, z(0) = 14;

利用Maple中龙格-库塔-菲尔伯格法(Runge–Kutta–Fehlberg法,简称 RKF45)可得数字解并做图。

2001年Tang等提出改进的蔡氏吸引子系统:.


d x ( t ) d t = α ( y ( t ) h ) {\displaystyle {\frac {\mathrm {d} x(t)}{\mathrm {d} t}}=\alpha *(y(t)-h)}

d y ( t ) d t = x ( t ) y ( t ) + z ( t ) {\displaystyle {\frac {\mathrm {d} y(t)}{\mathrm {d} t}}=x(t)-y(t)+z(t)}

d z ( t ) d t = β y ( t ) {\displaystyle {\frac {\mathrm {d} z(t)}{\mathrm {d} t}}=-\beta *y(t)}

其中

h := b s i n ( π x ( t ) 2 a + d ) {\displaystyle h:=-b*sin({\frac {\pi *x(t)}{2*a}}+d)}

参数:

params := alpha = 10.82, beta = 14.286, a = 1.3, b = .11, c = 7, d = 0;

初始条件:

initv := x(0) = 1, y(0) = 1, z(0) = 0;

利用Maple中龙格-库塔-菲尔伯格法(Runge–Kutta–Fehlberg法,简称 RKF45)可得数字解并做图:

1993年 Miranda & Stone 提出下列方程组:

d x ( t ) d t = 1 / 3 ( ( a + 1 ) x ( t ) + a c + z ( t ) y ( t ) ) + ( ( 1 a ) ( x ( t ) 2 y ( t ) 2 ) + ( 2 ( a + c z ( t ) ) ) x ( t ) y ( t ) ) {\displaystyle {\frac {\mathrm {d} x(t)}{\mathrm {d} t}}=1/3*(-(a+1)*x(t)+a-c+z(t)*y(t))+((1-a)*(x(t)^{2}-y(t)^{2})+(2*(a+c-z(t)))*x(t)*y(t))} 1 3 x ( t ) 2 + y ( t ) 2 {\displaystyle *{\frac {1}{3*{\sqrt {x(t)^{2}+y(t)^{2}}}}}}

d y ( t ) d t = 1 / 3 ( ( c a z ( t ) ) x ( t ) ( a + 1 ) y ( t ) ) + ( ( 2 ( a 1 ) ) x ( t ) y ( t ) + ( a + c z ( t ) ) ( x ( t ) 2 y ( t ) 2 ) ) {\displaystyle {\frac {\mathrm {d} y(t)}{\mathrm {d} t}}=1/3*((c-a-z(t))*x(t)-(a+1)*y(t))+((2*(a-1))*x(t)*y(t)+(a+c-z(t))*(x(t)^{2}-y(t)^{2}))} 1 3 x ( t ) 2 + y ( t ) 2 {\displaystyle *{\frac {1}{3*{\sqrt {x(t)^{2}+y(t)^{2}}}}}}

d z ( t ) d t = 1 / 2 ( 3 x ( t ) 2 y ( t ) y ( t ) 3 ) b z ( t ) {\displaystyle {\frac {\mathrm {d} z(t)}{\mathrm {d} t}}=1/2*(3*x(t)^{2}*y(t)-y(t)^{3})-b*z(t)}

参数: a = 10 , b = 8 3 , c = 137 5 {\displaystyle a=10,\quad b={\frac {8}{3}},\quad c={\frac {137}{5}}}

初始条件: x ( 0 ) = 8 , y ( 0 ) = 4 , z ( 0 ) = 10 {\displaystyle x(0)=-8,\quad y(0)=4,\quad z(0)=10}

利用Maple中龙格-库塔-菲尔伯格法(Runge–Kutta–Fehlberg法,简称 RKF45)可得数字解并做图:

2000年Aziz Alaoui 提出 PWL Duffing 方程:。

PWL 杜芬方程:

d x ( t ) d t = y ( t ) {\displaystyle {\frac {\mathrm {d} x(t)}{\mathrm {d} t}}=y(t)}

d y ( t ) d t = m 1 x ( t ) ( 1 / 2 ( m 0 m 1 ) ) ( | x ( t ) + 1 | | x ( t ) 1 | ) e y ( t ) + γ c o s ( ω t ) {\displaystyle {\frac {\mathrm {d} y(t)}{\mathrm {d} t}}=-m1*x(t)-(1/2*(m0-m1))*(|x(t)+1|-|x(t)-1|)-e*y(t)+\gamma *cos(\omega *t)}

参数:

params := e = .25, gamma = .14+(1/20)*i, m0 = -0.845e-1, m1 = .66, omega = 1; c := (.14+(1/20)*i),i=-25..25;

初始条件:

initv := x(0) = 0, y(0) = 0;

利用Maple中龙格-库塔-菲尔伯格法(Runge–Kutta–Fehlberg法,简称 RKF45)可得数字解并做图:


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