东北电力大学理学硕士学位论文
Abstract
The research boom of chaos theory was launched in the middle of the 20th century, and the
chaos control research also appeared in the researchers' view after the application of OGY
method research. Chaos control theory has a wide range of application fields, mainly playing an
important role in physics, chemistry, economics, medicine, biology and other fields. As the
research progresses and the field of study opens up, chaotic control methods also present
diversity: feedback control method, adaptive control method, impulse control method, etc.
In this paper, based on two types of discrete population systems with time lag, two types of
predator-prey systems, and two types of host-parasite systems, respectively, adaptive control
methods based on Backstepping, the trajectory tracking control methods, and chaotic control
methods based on BP neural networks are applied to study the chaotic control of the systems.
The details of the research are as follows.
(1) Chaos control study for two types of discrete population systems with time delay is
studied. First, the dynamical properties of the time-delayed ecosystem and the Moran-Ricker
model with time-delayed density-dependent birth rate regulation are analyzed separately, and the
existence of chaotic attractors is verified by plotting the Lyapunov exponential map and
bifurcation diagrams of the two types of systems. Then, the controllers of the two types of
chaotic systems are designed separately by using the adaptive control method based on
Backstepping. Finally, The effectiveness of the designed controller was verified by numerical
simulation with Matlab.
(2) Chaos control study for two types of predator-prey systems is studied. First, the
dynamical properties of a discrete predator-prey system with prey refuge and food chain systems
with Holling-II type and B-D type functional responses are analyzed separately, and the
existence of chaotic attractors is verified by plotting the Lyapunov exponential map and
bifurcation diagrams of the two types of systems. Then, the controllers of the two types of
chaotic systems are designed separately by using the trajectory tracking control method. Finally,
The effectiveness of the designed controller was verified by numerical simulation with Matlab.
(3) Chaos control study for two types of host-parasite systems is studied. First, the
host-parasite system with Hassell growth function and the host-parasitoid model with prolonged
diapause for the host are analyzed dynamically and the existence of chaotic attractors is verified
by plotting the Lyapunov exponential map and bifurcation diagrams of the two types of systems,
respectively. Then, the control method based on BP neural network is used to design a controller.