In this paper, stochastic dynamics of a single degree-of-freedom quasi-linear system with multitime delays and Poisson white noises are investigated using an approximate procedure based on the stochastic averaging method. The simplified equations, including the averaged stochastic differential equation and the averaged generalized Fokker-Planck-Kolmogorov equation, are obtained to calculate the probability density functions (PDFs) to explore stationary responses.The expression of the Lyapunov exponent is presented to examine the asymptotic stochastic Lyapunov stability. An illustrative example of a quasi-linear oscillator with two Poisson white noises controlled by two time-delayed feedback forces is worked out to demonstrate the validity of the proposed method. The approximate stationary PDFs of stochastic responses and asymptotic stochastic stability are demonstrated numerically and theoretically. The results show that the Gaussian white noise has a stronger influence on the dynamics than the Poisson white noise with a small mean arrival rate. Moreover, the influence of the time delay and noise parameters on stochastic dynamics is investigated. It is found that the PDFs under the Poisson white noise approach those under Gaussian white noise as the mean arrival rate increases. The time delay can induce stochastic P-bifurcation of the system. It is also found that the increase of time delay and the mean arrival rates of the Poisson white noises will broaden the unstable parameter region. The comparison between numerical and theoretical results shows the effectiveness of the proposed method.time delay, stochastic response and stability, Poisson white noise
| INTRODUCTIONTime delay can be experienced in many applications and fields, such as power, electronic technology, network, and transportation systems. The existence of time delay significantly affects the system behavior, especially for enormous nonlinear engineering structures. 1-3 For example, time delay in feedback control systems cannot be avoided because it takes time to detect the system state, calculate the control force, and transfer the control signal from the computer to the actuator. Time delay does not only affect the control effect but can cause