混合交通流时间序列的去趋势波动分析

应用去趋势波动分析法研究交通流时间序列的复杂性,探讨了混合交通流时间序列演变行为的标度指数.根据标度指数的变化特征,进而揭示交通流时间序列所具有的长程相关性和短程相关性.通过分析发现,存在一密度ρ,当ρ₁<ρ<ρ₂时,交通流时间序列具有长程相关性;而当ρ<ρ₁或ρ>ρ₂时,交通流时间序列具有短程相关性,即密度的变化影响着标度指数的变化.另外分析了在不同慢车比率条件下时间序列的标度指数,发现慢车比率的变化 关键词： 混合交通流 去趋势波动分析 时间序列 长程相关

Detrended fluctuation analysis of time series in mixed traffic flow

The detrended fluctuation analysis method is applied to analyse the complexity of traffic flow time series and the scale index is obtained, which is a parameter to depict the long term evolutionary behaviour of the mixed traffic flow time series. According to the changes of the scale index, it is shown that the traffic flow time series has long-range correlation characteristics or short-range correlation characteristics. It is found that the traffic flow series shows long-range correlation when the density ρ₁<ρ<ρ₂; and when ρ<ρ₁ or ρ>ρ₂, the time series displays short-range correlation. That is to say, the vehicle density plays an important role in the changes of the scale index. Additionally, we also found that the ratio of slow vehicles have influence on the changes of the scale index.