This paper investigates robust and reliable H filter design for a class of nonlinear networked control systems...
ZHAO Xia~1,TIAN Engang~2,WEI Jin~1,YUAN Yuehua~2 1.Nanjing College of Information Technology,Nanjing,210046,P.R.China 2.Institute of Information and Control Engineering,Nanjing Normal University,Nanjing,210042,P.R.China
With the increase of system scale, time delays have become unavoidable in nonlinear power systems, which add the complexity of system dynamics and induce chaotic oscillation and even voltage collapse events. In this paper, coexisting phenomenon in a fourth-order time-delayed power system is investigated for the first time with different initial conditions.With the mechanical power, generator damping factor, exciter gain, and time delay varying, the specific characteristic of the time-delayed system, including a discontinuous ＂jump＂ bifurcation behavior is analyzed by bifurcation diagrams, phase portraits, Poincar′e maps, and power spectrums. Moreover, the coexistence of two different periodic orbits and chaotic attractors with periodic orbits are observed in the power system, respectively. The production condition and existent domain of the coexistence phenomenon are helpful to avoid undesirable behavior in time-delayed power systems.
The magneto-rheological damper （MRD） is a promising device used in vehicle semi-active suspension systems, for its continuous adjustable damping output. However, the innate nonlinear hysteresis characteristic of MRD may cause the nonlinear behaviors. In this work, a two-degree-of-freedom （2-DOF） MR suspension system was established first, by employing the modified Bouc-Wen force-velocity （F-v） hysteretic model. The nonlinear dynamic response of the system was investigated under the external excitation of single-frequency harmonic and bandwidth-limited stochastic road surface. The largest Lyapunov exponent （LLE） was used to detect the chaotic area of the frequency and amplitude of harmonic excitation, and the bifurcation diagrams, time histories, phase portraits, and power spectrum density （PSD） diagrams were used to reveal the dynamic evolution process in detail. Moreover, the LLE and Kolmogorov entropy （K entropy） were used to identify whether the system response was random or chaotic under stochastic road surface. The results demonstrated that the complex dynamical behaviors occur under different external excitation conditions. The oscillating mechanism of alternating periodic oscillations, quasi-periodic oscillations, and chaotic oscillations was observed in detail. The chaotic regions revealed that chaotic motions may appear in conditions of mid-low frequency and large amplitude, as well as small amplitude and all frequency. The obtained parameter regions where the chaotic motions may appear are useful for design of structural parameters of the vibration isolation, and the optimization of control strategy for MR suspension system.
This paper concerns the robust H control design for wireless networked control systems(NCSs) with probabilisti...
ZHAO Xia~1,TIAN Engang~2,GU Zhou~3,CHEN Huwei~2 1.Nanjing College of Information Technology,Nanjing 210046,P.R.China 2.Institute of Information and Control Engineering,Nanjing Normal University,Nanjing 210042,P.R.China 3.College of Power Engineering,Nanjing Normal University,Nanjing 210042,P.R.China
针对复杂电子系统产生的传导EMI噪声,该文分别利用电偶极子模型、电路分析方法和散射参数方法提出了3种传导EMI噪声理论模型及其等效电路,包括因串扰引起的传导噪声模型,因接地不良引起的传导噪声模型,以及因PCB线缆阻抗失配引起的传导噪声模型。同时,还设计了一种串扰扼流圈以有效抑制因串扰引起的传导EMI噪声。实验结果表明,采用文中方法,某型商用车载导航和刷卡器能够通过GB 9254标准测试,噪声抑制效果分别可达44.8和29.28 dB V,从而验证了方法的有效性。
YAN WeiZHAO YangWANG ErtrongZHANG YuhuanQIU XiaohuiSUN HongyanCHEN Xueli
