Fig. 7
From: FPGA based implementation of a perturbed Chen oscillator for secure embedded cryptosystems
Sample phase portraits (y–z) of the long-term running of the system illustrating period doubling dynamics when varying the d parameter and experimentally with the Nexys 4 board (a) \(d=-60\); (b) \(d=-45\); (c) \(d=-35\); (d) \(d=-28\); (e) \(d=-22\) and (f) \(d=-5\). The initial conditions are: \(\left({x}_{0};{y}_{0};{z}_{0}\right)=(1;1;1)\) (blue) and \(\left({x}_{0};{y}_{0};{z}_{0}\right)=(-1;-1;-1)\) (red) presenting the asymmetry of the modified Chen system on its route to chaos. Corresponding oscilloscope photos in green confirming the numerical results.
