State Observer Synchronization Used in the Three-Dimensional Duffing System

Figure 9

The error curves driven by the outside periodic force 0.7cos𝑡 and the damping ratio fixed to 0.5. The parameter 𝑏 can be modified. There is no interference.

(a) The curve 𝑒₁ for 𝑥₁−𝑥₁

(b) The curve 𝑒₂ for 𝑥₂−𝑥₂

(c) The curve 𝑒₃ for 𝑥₃−𝑥₃