Subway Train Operation Adjustment Optimization Considering Based On Combined Strategy Under Delay

With the acceleration of China’s urbanization process,the subway lines in most cities in China are currently facing a situation of large passenger flows and high loads.In order to ease the pressure of passenger flow,the operating density of trains on subway lines has been increasing,which makes the subway at this stage have the characteristics of high traffic density and short tracking intervals.Once a train is delayed,it can easily cause its own and the aftereffects of the following trains,resulting in disorder in the operation of the subway,and even a large area delay and serious passenger detention.When dealing with more serious delays,the conventional method of time-exceeding operation ignores the distribution characteristics of line passenger flow,only mechanically shortens the stop time and interval operation time,resulting in its inability to fully and reasonably adjust the overall train capacity on the distribution line,and has limited effect in resuming planned train operations and alleviating passenger detention.Therefore,it is of great practical significance to carry out research on train operation adjustment methods that can alleviate passenger detention while speeding up the delay recovery.In view of the above problems,the following contents are researched.First,the reasons for the delay of subway trains,the types of train delays,and the propagation characteristics of delays are summarized.Based on the actual operation of the subway and the needs of passengers,the goals and principles that should be adjusted after train delays are discussed,and the working principles,advantages and disadvantages,and applicable conditions of various conventional and non-conventional operation adjustment strategies are specifically analyzed.Based on this,a combination adjustment strategy including a time-exceeding strategy,a deduction strategy,and a skip-stop strategy is established.Secondly,the impact of delay on the adjustment of dwell time,the relationship between dwell time and actual number of passengers on board,and the factors affecting dwell time are analyzed in detail.Based on this,a dynamic dwell time based on the passengers boarding and alighting at each station are implemented for the initial delayed trains and the subsequent trains,and a corresponding train stop time model is established in conjunction with the deduction strategy.At the same time,the interaction between passenger flow and train capacity is analyzed,and the passenger flow parameters are described mathematically based on this.Furthermore,the positive and negative impacts of the detained train strategy and the skip-stop strategy on the travel time of passengers are analyzed in detail.Based on the actual train operation conditions,train operation constraints and adjustment constraints are established,a model was developed with the target of minimizing the total travel time of passengers.According to the characteristics of the model,a corresponding nested genetic algorithm is designed.Finally,an actual subway route is used as a sample design example,and the validity of the method,model and algorithm is verified under four different delay situations,and the applicable conditions of the comprehensive adjustment method proposed in this paper are summarized.The results show that compared with the conventional adjustment method,the comprehensive adjustment method proposed in this paper can make the trains directly affected by the delay complete the late recovery in advance under various circumstances,and can significantly reduce the total additional travel time and passenger waiting time caused by the delay,and the optimization effect are respectively above 40% and 20%,and can effectively alleviate the situation of passengers waiting too long due to delays or the detention of passengers on the platform.