In order to analyze the stability impact of cooperative adaptive cruise control （CACC） platoon, an adaptive control model designed for the lead vehicle in a CACC platoon （LCACC model） in heterogeneous traffic flow...In order to analyze the stability impact of cooperative adaptive cruise control （CACC） platoon, an adaptive control model designed for the lead vehicle in a CACC platoon （LCACC model） in heterogeneous traffic flow with both CACC and manual vehicles is proposed. Considering the communication delay of a CACC platoon, a frequency-domain approach is taken to analyze the stability conditions of the novel lead-vehicle CACC model. Field trajectory data from the next-generation simulation （NGSIM） data is used as the initial condition. To account for car- following behaviors in reality, an intelligent driver model （IDM） is calibrated with the same NGSIM dataset from a previous study to model manual vehicles. The stability conditions of the proposed model are validated by the ring- road stability analysis. The ring-road test results indicate the potential of the LCACC model for improving the traffic flow stability impact of CACC platoons. Sensitivity analysis shows that the CACC fleet size has impact on the parameters of the LCACC model.展开更多
Complex dynamics are studied in the T system, a three-dimensional autonomous nonlinear system. In particular, we perform an extended Hopf bifurcation analysis of the system. The periodic orbit immediately following th...Complex dynamics are studied in the T system, a three-dimensional autonomous nonlinear system. In particular, we perform an extended Hopf bifurcation analysis of the system. The periodic orbit immediately following the Hopf bifurcation is constructed analytically for the T system using the method of multiple scales, and the stability of such orbits is analyzed. Such analytical results complement the numerical results present in the literature. The analytical results in the post-bifurcation regime are verified and extended via numerical simulations, as well as by the use of standard power spectra, autocorrelation functions, and fractal dimensions diagnostics. We find that the T system exhibits interesting behaviors in many parameter regimes.展开更多
In this paper,the authors analyze the stability of a class of interconnected systems withsubsystem unmodeled dynamics and dynamic interactions employing decentralized adaptive controllersdesigned by Wen,Zhou,and Wang ...In this paper,the authors analyze the stability of a class of interconnected systems withsubsystem unmodeled dynamics and dynamic interactions employing decentralized adaptive controllersdesigned by Wen,Zhou,and Wang (2008) in the presence of actuator failures.It will be shown that theglobal stability of the remaining closed-loop system is still ensured and the outputs are also regulatedto zero when some subsystems break down.展开更多
Complex large scale systems possess the characteristics of high dimensionality, large number of variables, strong nonlinearity, and parametric uncertainty. One of the effective approaches for the complex system modeli...Complex large scale systems possess the characteristics of high dimensionality, large number of variables, strong nonlinearity, and parametric uncertainty. One of the effective approaches for the complex system modeling is using a hybrid interconnected model to describe the dynamics of each subsystem. Usually, some subsystems could be represented by analytic mathematical models due to their explicit mechanisms; others could only be modeled by intelligent methods because of their complicated behaviors. This paper focuses on a kind of large-scale uncertain systems with hybrid interconnected models, a part of which described by linear differential-equations and another part represented by Takagi-Sugeno fuzzy models. Through constructing a set of independent lower-dimensional linear matrix inequalities, and solving them in parallel, a novel robust stability analysis method is proposed. Thus the computational complexity is greatly reduced. Computer simulation is conducted to validate the effectiveness and efficiency of the proposed method.展开更多
基金The National High Technology Research and Development Program of China(863 Program)(No.2011AA110405)
文摘In order to analyze the stability impact of cooperative adaptive cruise control （CACC） platoon, an adaptive control model designed for the lead vehicle in a CACC platoon （LCACC model） in heterogeneous traffic flow with both CACC and manual vehicles is proposed. Considering the communication delay of a CACC platoon, a frequency-domain approach is taken to analyze the stability conditions of the novel lead-vehicle CACC model. Field trajectory data from the next-generation simulation （NGSIM） data is used as the initial condition. To account for car- following behaviors in reality, an intelligent driver model （IDM） is calibrated with the same NGSIM dataset from a previous study to model manual vehicles. The stability conditions of the proposed model are validated by the ring- road stability analysis. The ring-road test results indicate the potential of the LCACC model for improving the traffic flow stability impact of CACC platoons. Sensitivity analysis shows that the CACC fleet size has impact on the parameters of the LCACC model.
文摘Complex dynamics are studied in the T system, a three-dimensional autonomous nonlinear system. In particular, we perform an extended Hopf bifurcation analysis of the system. The periodic orbit immediately following the Hopf bifurcation is constructed analytically for the T system using the method of multiple scales, and the stability of such orbits is analyzed. Such analytical results complement the numerical results present in the literature. The analytical results in the post-bifurcation regime are verified and extended via numerical simulations, as well as by the use of standard power spectra, autocorrelation functions, and fractal dimensions diagnostics. We find that the T system exhibits interesting behaviors in many parameter regimes.
文摘In this paper,the authors analyze the stability of a class of interconnected systems withsubsystem unmodeled dynamics and dynamic interactions employing decentralized adaptive controllersdesigned by Wen,Zhou,and Wang (2008) in the presence of actuator failures.It will be shown that theglobal stability of the remaining closed-loop system is still ensured and the outputs are also regulatedto zero when some subsystems break down.
文摘Complex large scale systems possess the characteristics of high dimensionality, large number of variables, strong nonlinearity, and parametric uncertainty. One of the effective approaches for the complex system modeling is using a hybrid interconnected model to describe the dynamics of each subsystem. Usually, some subsystems could be represented by analytic mathematical models due to their explicit mechanisms; others could only be modeled by intelligent methods because of their complicated behaviors. This paper focuses on a kind of large-scale uncertain systems with hybrid interconnected models, a part of which described by linear differential-equations and another part represented by Takagi-Sugeno fuzzy models. Through constructing a set of independent lower-dimensional linear matrix inequalities, and solving them in parallel, a novel robust stability analysis method is proposed. Thus the computational complexity is greatly reduced. Computer simulation is conducted to validate the effectiveness and efficiency of the proposed method.
