Active Control of the Parametric Resonance in the Modified Rayleigh-Duffing Oscillator

The present paper examines the active control of parametric resonance in modified Rayleigh-Duffing oscillator. We used the method of averaging to obtain steady-state solutions. We have found the critical value of the parametrical amplitude which indicates the boundary layer where the control is efficient in reducing the amplitude vibration. We have also found the effects of excitation parameters and time-delay on dynamical of this system with the principal parametric resonance. We have obtained for this oscillator the Hopf bifurcation and saddle-node bifurcation for certains values of parametric parameters and time-delay. We have studied the influence of parameter $k_2$ which is one of the parameters which modify the ordinary Rayleigh-Duffing oscillator. We have discussed the appropriate choice of the time-delay and control gain. We finally studied the stability of fixed point and it is found that the appropriate choice of the time-delay can broaden the stable region of the non-trivial steady-state solutions which will enhance the control efficiency. Numerical simulations are performed in order to confirm analytical results. 15 pages, 7 figures; Submitted to The African Review of Physics