Optimization For Train Operation Plan Of Combination Of Express-Local Train And Multi-Group In Urban Rail Transit Considering The Equilibrium Of Capacity Rate

With the continuous expansion of China's cities,a large number of people have flooded into the surrounding areas of the city,which has led to an increasing proportion of long-distance passenger flows.In order to adapt to the change,urban rail transit lines have mostly adopted operational organization mode of express-local train.However,when the proportion of long-distance passenger flow is further increased,the operation of a single-group express-local train plan will aggravate the disequilibrium of the capacity rate between the express trains and local trains,that is,the capacity rate of express trains is too high,which reduces the travel experience of the express passengers.The capacity rate of local train is too low,which causes a waste of capacity of slow trains.Therefore,in order to optimize the equilibrium of capacity rate of express train and local train,and improve the travel experience of express passengers,and allocate transportation capacity rationally,the combination of the operation mode of express-local train and multi-group is considered.The main research work and conclusions of the thesis are as follows:(1)Based on the analysis of the typical case of combination of express-local train and multi-group of KEISEI line in Japan and line 16 of urban rail transit in Shanghai,combined with the existing research,the preconditions,combination modes,influencing factors and evaluation index of scheme optimization of the combination of the operation mode of express-local train and multi-group are proposed.(2)A generalized cost function considering passengers' comfort is established.And the time parameters and comfort coefficients in the function are calibrated according to the passengers' characteristics of travel behavior and the survey data of passengers' comfort score under different capacity rates.A method for calculating the probability of passengers' travel path selection is proposed.(3)A bi-level programming model is established to optimize the operation plan of the combination of express-local train and multi-group considering the equilibrium of capacity rate.The upper model is the optimization model for the operation plan of express-local train,aiming at determining the optimal stop plan of express trains,so as to minimize the generalized travel cost of all passengers and the operation cost of enterprises.The lower model is the capacity rate equilibrium optimization model,which aims at determining the optimal marshalling scheme of express-local train,and optimizing the capacity rate equilibrium of express trains and local trains.Finally,a heuristic algorithm of "genetic&exhaustive iteration" is designed to obtain the optimal solution of combinatorial optimization.(4)Taking a certain line of a city as a case,the model is applied.The obtained optimal plan is compared with the plan of stopping stations by stations and the plan of single-group express-local train to verify the rationality and effectiveness of the model and algorithm.Compared with the plan of stopping stations by stations,the optimization rate of the generalized travel cost of all passengers is 1.4%,the optimization rate of the operation cost of enterprises is 2.7%.Compared with the plan of single-group express-local train,the optimization rate of generalized travel cost of all passengers is 1.0%,and the optimization rate of passengers' comfort cost is 24.5%,and the operation cost of enterprises optimization rate is 0.47%,and the optimization rate of capacity rate equalization coefficient 12.1%,which shows that the combination of express-local train and multi-group scheme is better than the plan of stopping stations by stations and the plan of single-group express-local train.(5)Through sensitivity analysis of the proportion of long-distance passenger flow,the conclusion is drawn that when the proportion of long-distance passengers is between 70%and 90%,the plan of combination of express-local train and multi-group is optimal.Sensitivity analysis of the upper limit of the capacity rate shows that the increase of the upper limit of the capacity rate is beneficial to diversify the marshalling scheme and reduces the operating cost,but it will bring to the result of declining of passenger travel experience.Sensitivity analysis of the train stopping time shows that the longer the train stopping time is,the higher the optimization rate of travel time of all passengers of the combined optimization scheme is.