|
There are two typical issues in the smooth transition algorithm, which is commonly used for coordinated control of urban road traffic signals. Firstly, when selecting the transition adjustment strategy, the inherent relationship between the two transition adjustment strategies, extension and shortening, can be easily ignored. Only a single transition adjustment strategy can be chosen directly, and the strategy tends to be unsatisfying. Secondly, deficiencies exist when understanding coordinated and non-coordinated phase requirements, and the distribution can be uneven when the green signal ratio is allocated in the transition adjustment scheme. To address these issues, this study explores the internal relationship between the two transition adjustment strategies, namely, extension and shortening, and defines the periodic correlation adjustment amount. Comparing and analyzing the impact of the amount of adjustment in the two strategies on the total transition period and duration, they account for 5%, 15%, and 25% of the cycle, respectively. It reveals that the adjustment strategy produced under a single rule cannot meet the basic needs of the shorter total transition adjustment time and lacks the general rule of response mechanism to the background cycle change trend. Targeting embedded traffic signal control devices, we further propose to optimize the speed of adjustment and small fluctuation of the scheme as the goal. This model includes two levels of decision indicators, TS and Dev, which characterize the adjustment speed and the deviation of median value in the representation cycle. After adjusting the strategy and parameters following the model output, we fully consider the difference in demand for access to the experience and release efficiency between the coordinated and uncoordinated phases. Overall, the complete construction of a coordinated transition adjustment process consists of three parts: identification of transition adjustment, the establishment of a decision model and implementation of transition adjustment.
|
