Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a method for constructing a same-urbanization intercity passenger flow generation model based on traffic reachability, or a method for improving the efficiency of calibrating the same-urbanization intercity passenger flow data of a traffic model, or a method for improving the accuracy of the same-urbanization intercity passenger flow data of the traffic model, or a method for improving the early warning of the same-urbanization intercity passenger flow data of the traffic model, which comprises the steps of basic data acquisition, average intercity passenger flow generation rate calibration, initial intercity passenger flow generation quantity calculation, trip mode utility function calibration, reachability index construction and intercity passenger flow generation quantity correction. The method is suitable for the refined prediction of the passenger flow generation amount among cities in the same urbanization process, and the model is subjected to parameter calibration by using multi-source big data; research results show that the city-sharing intercity passenger flow generation model based on traffic accessibility has good feasibility and effectiveness, a new thought and method are provided for predicting the intercity passenger flow, the method for improving the calibration efficiency of the city-sharing intercity passenger flow data of the traffic model has high accuracy and effectiveness, the prediction efficiency and accuracy are improved for predicting the intercity passenger flow, and the method has important guiding significance on refined intercity passenger flow prediction.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a method for constructing a same-city intercity passenger flow generation model based on traffic reachability comprises the following steps:
firstly, basic data acquisition: population POP for acquiring and researching traffic cells k of city based on big data technologykAnd employment data EMPkPOP of population in different circle levels i (such as core area, main city area and peripheral area)iAnd number of employment EMPi(ii) a Current passenger flow Q of different circle layers i and j between citiesijAnd Qji;
Passenger flow Q based on current situationijAnd QjiObtaining the current intercity passenger flow generation amount G of different circle layersiThe current situation of intercity passenger flow attraction Ai;
Gi=Qij (1)
Ai=Qji (2)
Secondly, calibrating the average intercity passenger flow rate (including generation rate and attraction rate) of each circle of layers: calibrating the average intercity passenger flow trip rate of each circle by utilizing the intercity passenger flow generation amount, the attraction amount, the population and employment data of different circles among cities acquired in the first step
An intercity passenger flow generation model is constructed based on a generation rate method as follows:
in the formula (3), the reaction mixture is,
average intercity passenger flow generation rate of residential population and employment posts of circle layer i;
in the formula (4), the reaction mixture is,
the average intercity passenger flow attraction rate of the residential population and employment posts of the circle layer i;
thirdly, calculating the initial intercity passenger flow generation amount of each traffic cell: calculating the initial intercity passenger flow generation amount of the cell k belonging to different circle layers by using the average intercity passenger flow trip rate of each circle layer obtained in the second step
Initial inter-city passenger flow attraction
Fourthly, calibrating the travel utility functions of ground traffic (including cars, taxis and passenger buses) and rail traffic (including intercity railways and subways);
fifthly, constructing a reachability index: method for calculating accessibility according to opportunity accumulation and constructing accessibility index Rk;
And sixthly, correcting the initial inter-city passenger flow generation amount of the traffic cell: according to the formula (7) and the formula (8) respectivelyCalculating the corrected traffic cell intercity passenger flow generation GkIntercity passenger flow attraction Ak;
In the formulas (7) and (8),
the average reachability is the average value of all cell reachability in each circle of layers.
Further, the specific steps of acquiring the demographic employment data of each cell (or each circle of layer) in the first step are as follows: the residential population and the working population of a unit grid unit are obtained according to the Internet positioning data, and then the grid population is associated with the boundaries of the traffic cells (or all circle layers), so that the residential population and the employment post number of each traffic cell (or all circle layers) can be obtained.
Further, the specific steps of acquiring the current passenger flows of different circles among cities in the first step are as follows: the method comprises the steps of firstly establishing a matching relation between an urban circle layer and a user stop point by using internet positioning data, and then acquiring intercity travel passenger flow by identifying the population flow direction.
Further, the specific steps of calibrating the trip utility function in the fourth step are as follows:
s41, acquiring the proportion of the current situation that the local city cell k reaches the adjacent city cell g by adopting two travel modes of ground traffic (including cars, taxis and passenger buses) and rail traffic (including intercity railways and subways)
The rail transit passenger flow can be obtained by using railway ticket business or bus card swiping data, and the ground transit passenger flow can be obtained by subtracting the rail transit passenger flow from the current passenger flow.
S42: and (5) calibrating the travel utility of the travel of the local city cell k to the selection mode m of the adjacent city cell g according to the formula (9) by combining the proportions of the various modes of travel obtained in the S41
Sum trip utility function
Wherein, when m takes 1, the ground traffic is represented, and when m takes 2, the track traffic is represented:
in the formula (9), the reaction mixture is,
the time of the travel in the vehicle is,
is the travel time outside the automobile,
α
1、α
2is a calibrated parameter; the time variables in this step are current values;
s43: the parameters obtained in S42
α
1、α
2And planning the travel time of the year in the vehicle
And travel time outside the vehicle
Substituting the formula (9) to obtain the proportion of travel of the planning year from the local city cell k to the adjacent city cell g in the selection mode m;
further, in the fifth step, the reachability index RkThe specific calculation steps are as follows:
s51, calculating the chance number O of the neighbor cell g obtained from the cell k of the local city within the time threshold T according to the formula (10)k(T), which is a weighted sum of the number of acquisition opportunities in different ways;
in the formula (10), when m is 1, the ground traffic is represented, when m is 2, the track traffic is represented,
the table type local city cell k adopts the adjacent city opportunity number obtained by the mode m, and the opportunity can be referred to by population and/or employment post; the time threshold T is obtained by the quantile of the current intercity travel time; time of flight t
kgCalculated by traffic network and equal to travel time in vehicle
External travel time of car
The quantile value can be 95%;
s52, calculating the accessibility index Rk: method for calculating reachability from chance accumulation, RkDefined as the ratio of the number of available neighbor opportunities in cell k to the total number of available neighbor opportunities within time threshold T:
in formula (11), O (T)max) Indicating that the number of all opportunities that can be reached for a sufficiently long time is equal to the number of opportunities for all cells in the neighborhood.
Compared with the prior art, the invention has the advantages that:
1) the traffic reachability index is creatively introduced, a new intercity passenger flow generation model is constructed, and the influence of factors such as location, distance, traffic infrastructure and the like on intercity passenger flow generation amount can be comprehensively considered;
2) the method utilizes the modern internet big data to construct the intercity passenger flow generation model, overcomes the shortage of sample size of the traditional manual sampling inquiry survey data, and gets rid of the limitation of single city administrative division.
3) The method for generating the same-urbanization intercity passenger flow model is suitable for the traffic cell partition with small granularity, and provides a new thought and a new method for refined intercity passenger flow prediction.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Example 1:
a method for constructing a same-city intercity passenger flow generation model based on traffic reachability is shown in the attached figure 1 and comprises the following steps:
firstly, acquiring basic data: population POP for researching each traffic district k of citykAnd employment data EMPkPOP of population of different circle levels i (core area, main city area, peripheral area)iAnd number of employment EMPi(ii) a Current passenger flow Q of different circle layers i and j between citiesijAnd Qji(ii) a The data are generally obtained by traditional resident trip investigation or statistical departments of relevant cities in the urban traffic model, but the acquisition of the resident trip investigation data is difficult to break through the administrative boundary barrier and cannot provide support for the regional traffic model, and the big data technology provides possibility for acquiring data of intercity outgoing amount, population and employment posts.
The specific steps for acquiring the population employment data of each cell (or each circle layer) are as follows: the method comprises the steps of firstly obtaining residential population and working population of a unit grid unit (for example, 200 x 200 meters) according to Internet positioning data, and then associating the grid population with the boundaries of traffic cells (or all circle layers) to obtain the residential population and employment post number of each traffic cell (or all circle layers).
The specific steps for acquiring the current passenger flows of different circles among cities are as follows: firstly, establishing a matching relation between an urban circle layer and a user stop point by using internet positioning data, and then acquiring intercity travel passenger flow by identifying the flow direction of population;
intercity passenger flow Q based on current situationijAnd QjiCollecting and obtaining the current intercity passenger flow generation amount G of different circle layersiThe current situation of intercity passenger flow attraction AiWhere i, j ∈ { core region, primary metropolitan region, peripheral region };
Gi=Qij (1)
Ai=Qji (2)
secondly, calibrating the average intercity passenger flow rate (including generation rate and attraction rate) of each circle of layers: and calibrating the average intercity passenger flow trip rate of each circle layer by using the intercity passenger flow generation amount, the attraction amount, the population and employment data of different circle layers obtained in the first step. An intercity passenger flow generation model is constructed based on a generation rate method as follows:
in the formula (3), the reaction mixture is,
the average intercity passenger flow generation rate of the residential population and employment posts of the circle layer i is shown;
in the formula (4), the reaction mixture is,
the average intercity passenger flow attraction rate of the residential population and employment posts of the circle layer i;
thirdly, calculating the initial inter-city passenger flow generation amount of each traffic cell: calculating the initial intercity passenger flow generation amount of the cell k belonging to different circle layers by using the average intercity passenger flow trip rate of each circle layer obtained in the second step
Initial intercity passenger flow attraction
Fourthly, calibrating utility functions of ground traffic (including cars, taxis and passenger buses) and rail traffic (including intercity railways and subways);
s41: obtaining the proportion of the current situation that the local city cell k reaches the adjacent city cell g by adopting two travel modes of ground traffic (including cars, taxis and passenger buses) and rail traffic (including intercity railways and subways)
The rail transit passenger flow can be obtained by using railway ticket business or bus card swiping data, and the ground transit passenger flow can be obtained by subtracting the rail transit passenger flow from the current passenger flow.
S42: and (5) calibrating the utility function of the travel of the local city cell k to the selection mode m of the adjacent city cell g according to the formula (7) by combining the proportions of the travel of the modes obtained in the S41
Wherein m is 1 represents a ground intersectionOn, when m takes 2, the rail transit is represented:
in the formula (7), the reaction mixture is,
representing the traveling utility of ground traffic and rail traffic;
the time of the travel in the vehicle is,
is the travel time outside the automobile,
α
1、α
2is a calibrated parameter; the time variables in this step are current values;
s43: parameters obtained in S42
α
1、α
2And planning the travel time of the year in the vehicle
And travel time outside the vehicle
Substituting the formula (9) into the formula (9), and obtaining the proportion of travel of the planning year from the local city cell k to the adjacent city cell g in the selection mode m;
fifthly, constructing a reachability index: method for calculating accessibility according to opportunity accumulation and constructing accessibility index Rk;
Traffic accessibility reflects the inherent link between transportation systems and land use and is a primary goal of traffic planning. Reachability is often used to assess the convenience of public transportation systems, or the ease with which a group of people can reach a facility in a public place (e.g., hospital, park, school), or to investigate the vulnerability of a network with changes in reachability. At present, no research is available for introducing traffic accessibility indexes into an intercity passenger flow generation model.
The invention adopts the concept of cumulative-opportunity (cumulative-opportunity) to construct the reachability index suitable for predicting the generation amount of intercity passenger flow. The accumulated opportunity describes the number of opportunities (such as working posts) which can be developed by a traveler in contact with the traveler in a certain travel time range by using a certain transportation mode from a certain place. As shown in fig. 2, it is possible for a traveler to obtain all the opportunities for development as long as a given travel time is sufficiently long.
S51: calculating the chance number O of the neighbor cell g obtained from the cell k in the local city within the time threshold T according to the formula (8)k(T) obtaining the weighted sum of the opportunity numbers by adopting different trip modes;
in the formula (8), the reaction mixture is,
the table type local city cell k adopts the adjacent city opportunity number obtained by the mode m, and the opportunity can be referred to as population and employment post; the time threshold T is obtained by the quantile of the current intercity travel time; time of flight t
kgCalculated by traffic network and equal to travel time in vehicle
External travel time of car
The quantile value may be 95%.
S52: calculating a reachability index Rk: according to the concept of cumulative opportunity, RkDefined as the ratio of the number of available neighbor opportunities in cell k to the total number of available neighbor opportunities within time threshold T:
in formula (9), O (T)max) Indicating that the number of all opportunities that can be reached for a sufficiently long time is equal to the number of opportunities for all cells in the neighborhood.
And sixthly, correcting the initial inter-city passenger flow generation amount of the traffic cell: respectively calculating and obtaining the corrected traffic cell intercity passenger flow generation amount G according to a formula (10) and a formula (11)kInter-city passenger flow attraction amount Ak;
In the formulas (10) and (11), n is the number of traffic cells,
the average reachability is the average value of all cell reachability in each circle of layers.
The method for generating the same-urbanization intercity passenger flow model constructed in the embodiment is suitable for the traffic cell partition with small granularity, and provides a new thought and a new method for refined intercity passenger flow prediction.
Example 2:
a method for improving the efficiency of calibrating the data of the city-sharing intercity passenger flow of a traffic model is characterized in that a construction model is generated based on the city-sharing intercity passenger flow of traffic reachability, as shown in the attached figure 1, the method comprises the following steps:
firstly, acquiring basic data: population POP for researching each traffic district k of citykAnd employment data EMPkPOP of population of different circle levels i (core area, main city area, peripheral area)iAnd employment quantity EMPi(ii) a Current passenger flow Q of different circle layers i and j between citiesijAnd Qji(ii) a The above data are inThe urban traffic model is generally obtained by a traditional resident trip survey or a statistical department of a related city, but the acquisition of resident trip survey data is difficult to break through the administrative boundary barrier and cannot provide support for the regional traffic model, and the big data technology provides possibility for acquiring data of intercity travel volume, population and employment post.
The specific steps for acquiring the population employment data of each cell (or each circle layer) are as follows: the method comprises the steps of firstly obtaining residential population and working population of a unit grid unit (for example, 200 x 200 meters) according to Internet positioning data, and then associating the grid population with the boundaries of traffic cells (or all circle layers) to obtain the residential population and employment post number of each traffic cell (or all circle layers).
When the internet positioning data is acquired in real time, based on real-time statistics and prediction of historical big data, according to different passenger flow distribution base numbers of research cities, peak time periods, unit grid unit coordinates and threshold value ranges [ a, b ] of residential population and working population are preset. And when the residential population and the working population of the unit grid cell are lower than the lowest threshold value a, automatically defaulting the unit grid data as a statistical average value according to the statistical average value of the current historical same time period. The lower the population density is, the smaller the working population number is, the average value of the statistical values is automatically defaulted to the unit grid data according to the statistical values of the current history in the same period, so that the data acquisition complexity is effectively reduced, the data processing amount is reduced, the data acquisition amount is reduced, and the data real-time acquisition efficiency is improved.
The specific steps for acquiring the current passenger flows of different circles among cities are as follows: firstly, establishing a matching relation between an urban circle layer and a user stop point by using internet positioning data, and then acquiring intercity travel passenger flow by identifying the flow direction of population;
intercity passenger flow Q based on current situationijAnd QjiAnd collecting and obtaining the current intercity passenger flow generation amount G of different circlesiThe current situation of intercity passenger flow attraction AiWhere i, j ∈ { core region, primary metropolitan region, peripheral region };
Gi=Qij (1)
Ai=Qji (2)
secondly, calibrating the average intercity passenger flow trip rate (including the generation rate and the attraction rate) of each circle: and calibrating the average intercity passenger flow trip rate of each circle layer by using the intercity passenger flow generation amount, the attraction amount, the population and employment data of different circle layers obtained in the first step. An intercity passenger flow generation model is constructed based on a generation rate method as follows:
in the formula (3), the reaction mixture is,
the average intercity passenger flow generation rate of the residential population and employment posts of the circle layer i is shown;
in the formula (4), the reaction mixture is,
the average intercity passenger flow attraction rate of the residential population and employment posts in the circle layer i;
thirdly, calculating the initial inter-city passenger flow generation amount of each traffic cell: calculating the initial intercity passenger flow generation amount of the cell k belonging to different circle layers by using the average intercity passenger flow trip rate of each circle layer obtained in the second step
Initial inter-city passenger flow attraction
Fourthly, calibrating utility functions of ground traffic (including cars, taxis and passenger buses) and rail traffic (including intercity railways and subways);
s41: obtaining the proportion of the current situation that the local city cell k reaches the adjacent city cell g by adopting two travel modes of ground traffic (including cars, taxis and passenger buses) and rail traffic (including intercity railways and subways)
The rail transit passenger flow can be obtained by using railway ticket business or bus card swiping data, and the ground transit passenger flow can be obtained by subtracting the rail transit passenger flow from the current passenger flow.
S42: and (5) calibrating the utility function of the travel of the local city cell k to the selection mode m of the adjacent city cell g according to the formula (7) by combining the proportions of the travel of the modes obtained in the S41
Wherein, m represents ground traffic when taking 1, and represents rail traffic when taking 2:
in the formula (7), the reaction mixture is,
representing the traveling utility of ground traffic and rail traffic;
the time of the travel in the vehicle is,
is the travel time outside the automobile,
α
1,α
2is a calibrated parameter; this step is carried outThe time variables in the step are current values;
s43: parameters obtained in S42
α
1,α
2And planning the travel time of the year in the vehicle
And travel time outside the vehicle
Substituting the formula (9) into the formula (9), and obtaining the proportion of travel of the planning year from the local city cell k to the adjacent city cell g in the selection mode m;
fifthly, constructing a reachability index: method for calculating accessibility according to opportunity accumulation and constructing accessibility index Rk;
Traffic accessibility reflects the inherent link between transportation systems and land use and is a primary goal of traffic planning. Reachability is often used to assess the convenience of public transportation systems, or the ease with which a group of people can reach a facility in a public place (e.g., hospital, park, school), or to investigate the vulnerability of a network with changes in reachability. At present, no research is available for introducing traffic accessibility indexes into an intercity passenger flow generation model.
The method adopts the concept of cumulative-opportunity (cumulative-opportunity) to construct the reachability index suitable for the inter-city passenger flow generation amount prediction. The accumulated opportunity describes the number of opportunities (such as working posts) which can be developed by a traveler in contact with the traveler in a certain travel time range by using a certain transportation mode from a certain place. As shown in fig. 2, it is possible for a traveler to obtain all the opportunities for development as long as a given travel time is sufficiently long.
S51: calculating the chance number O of the neighbor cell g obtained from the cell k in the local city within the time threshold T according to the formula (8)k(T) obtaining the weighted sum of the opportunity numbers by adopting different trip modes;
in the formula (8), the reaction mixture is,
the table type local city cell k adopts the adjacent city opportunity number obtained by the mode m, and the opportunity can be referred to as population and employment post; the time threshold T is obtained by the quantile of the current intercity travel time; time of flight t
kgCalculated by traffic network and equal to travel time in vehicle
External travel time of car
The quantile value may be 95%.
S52: calculating a reachability index Rk: according to the concept of cumulative chance, RkDefined as the ratio of the number of available neighbor opportunities in cell k to the total number of available neighbor opportunities within time threshold T:
in formula (9), O (T)max) Indicating that the number of all opportunities that can be reached for a sufficiently long time is equal to the number of opportunities for all cells in the neighborhood.
And sixthly, correcting the initial inter-city passenger flow generation amount of the traffic cell: respectively calculating and obtaining the corrected traffic cell intercity passenger flow generation amount G according to a formula (10) and a formula (11)kInter-city passenger flow attraction amount Ak;
In the formulas (10) and (11), n is the number of traffic cells,
the average reachability is the average value of all cell reachability in each circle of layers.
The embodiment is based on the same-urbanization inter-city passenger flow generation model, can be suitable for the traffic district partitions with small granularity, can simplify a data acquisition mode by combining large historical population passenger flow data, can efficiently acquire real-time data, and provides efficiency guarantee for refined inter-city passenger flow prediction.
Example 3:
a method for improving accuracy of intercity passenger flow data of a traffic model with a city, as shown in fig. 1, comprising the following steps:
firstly, acquiring basic data: population POP for researching each traffic district k of citykAnd employment data EMPkPopulation POP of different circle layers i (core area, main city area and peripheral area)iAnd number of employment EMPi(ii) a Current passenger flow Q of different circle layers i and j between citiesijAnd Qji(ii) a The data are generally obtained by traditional resident trip survey or statistical departments of related cities in the urban traffic model, but the acquisition of the resident trip survey data is difficult to break through the administrative boundary barrier and cannot provide support for the regional traffic model, and the big data technology provides possibility for acquiring data of inter-city traffic volume, population and employment posts.
The specific steps for acquiring the population employment data of each cell (or each circle layer) are as follows: the method comprises the steps of firstly obtaining residential population and working population of a unit grid unit (for example, 200 x 200 meters) according to Internet positioning data, and then associating the grid population with the boundaries of traffic cells (or all circle layers) to obtain the residential population and employment post number of each traffic cell (or all circle layers).
When the internet positioning data is acquired in real time, based on real-time statistics and prediction of historical big data, according to different passenger flow distribution base numbers of research cities, the peak time period, unit grid unit coordinates and threshold value ranges [ a, b ] of resident population and working population are set. When the resident population and the working population in the unit grid cell coordinate are higher than the highest threshold b, the unit grid cell can be provided with sub-grid cells, and the value range of the sub-grid cells can be adjusted in real time or periodically according to the resident population density, the working population number, emergency events, peak periods and the like of each cell, for example, the value range can be dynamically adjusted from 50 meters by 50 meters to 100 meters by 100 meters. When the population density is higher, the working population number is larger, and/or in a peak period, the unit grid unit sets the sub-grid more accurately, so that the positioning data acquisition accuracy is higher.
The specific steps for acquiring the current passenger flows of different circles among cities are as follows: firstly, establishing a matching relation between an urban circle layer and a user stop point by using internet positioning data, and then acquiring intercity travel passenger flow by identifying the flow direction of population;
intercity passenger flow Q based on current situationijAnd QjiCollecting and obtaining the current intercity passenger flow generation amount G of different circle layersiThe current situation of intercity passenger flow attraction AiWhere i, j ∈ { core region, primary metropolitan region, peripheral region };
Gi=Qij (1)
Ai=Qji (2)
secondly, calibrating the average intercity passenger flow rate (including generation rate and attraction rate) of each circle of layers: and calibrating the average intercity passenger flow trip rate of each circle layer by using the intercity passenger flow generation amount, the attraction amount, the population and employment data of different circle layers obtained in the first step. The intercity passenger flow generation model is constructed based on a generation rate method as follows:
in the formula (3), the reaction mixture is,
the average intercity passenger flow generation rate of the residential population and employment posts of the circle layer i is shown;
in the formula (4), the reaction mixture is,
the average intercity passenger flow attraction rate of the residential population and employment posts of the circle layer i;
thirdly, calculating the initial inter-city passenger flow generation amount of each traffic cell: calculating the initial intercity passenger flow generation amount of the cell k belonging to different circle layers by using the average intercity passenger flow trip rate of each circle layer obtained in the second step
Initial intercity passenger flow attraction
Fourthly, calibrating utility functions of ground traffic (including cars, taxis and passenger buses) and rail traffic (including intercity railways and subways);
s41: obtaining the proportion of the current situation that the local city cell k reaches the adjacent city cell g by adopting two travel modes of ground traffic (including cars, taxis and passenger buses) and rail traffic (including intercity railways and subways)
The rail transit passenger flow can be obtained by using railway ticket business or bus card swiping data, and the ground transit passenger flow can be obtained by subtracting the rail transit passenger flow from the current passenger flow.
S42: combining the proportions of all the modes of travel obtained in S41, and marking according to the formula (7)Determining utility function of travel of g selection mode m for local city cell k to reach neighboring city cell
Wherein, when m takes 1, the ground traffic is represented, and when m takes 2, the track traffic is represented:
in the formula (7), the reaction mixture is,
representing the traveling utility of ground traffic and rail traffic;
the time of the travel in the vehicle is,
is the travel time outside the automobile,
α
1、α
2is a calibrated parameter; the time variables in this step are all current values;
s43: the parameters obtained in S42
α
1、α
2And planning the travel time of the year in the vehicle
And travel time outside the vehicle
Substituting the formula (9) into the formula (9), and obtaining the proportion of travel of the planning year from the local city cell k to the adjacent city cell g in the selection mode m;
fifthly, constructing a reachability index: method for calculating accessibility according to opportunity accumulation and constructing accessibility index Rk;
Traffic accessibility reflects the inherent link between transportation systems and land use and is a primary goal of traffic planning. Reachability is often used to assess the convenience of public transportation systems, or the ease with which a group of people can reach a facility in a public place (e.g., hospital, park, school), or to investigate the vulnerability of a network with changes in reachability. At present, no research is available for introducing traffic accessibility indexes into an intercity passenger flow generation model.
The invention adopts the concept of cumulative-opportunity (cumulative-opportunity) to construct the reachability index suitable for predicting the generation amount of intercity passenger flow. The accumulated opportunity describes the number of opportunities (such as working posts) which can be developed by a traveler in contact with the traveler in a certain travel time range by using a certain transportation mode from a certain place. As shown in fig. 2, it is possible for a traveler to obtain all the opportunities for development as long as a given travel time is sufficiently long.
S51: calculating the opportunity number O of the neighbor cell g obtained from the cell k of the local city within the time threshold T according to the formula (8)k(T) obtaining the weighted sum of the opportunity numbers by adopting different trip modes;
in the formula (8), the reaction mixture is,
the table type local city cell k adopts the adjacent city opportunity number obtained by the mode m, and the opportunity can be referred to as population and employment post; the time threshold T is obtained by the quantile of the current intercity travel time; time of flight t
kgCalculated by traffic network and equal to travel time in vehicle
External travel time of car
The quantile value may be 95%.
S52: calculating a reachability index Rk: according to the concept of cumulative opportunity, RkDefined as the ratio of the number of available neighbor opportunities in cell k to the total number of available neighbor opportunities within time threshold T:
in formula (9), O (T)max) Indicating that the number of all opportunities that can be reached for a sufficiently long time is equal to the number of opportunities for all cells in the neighborhood.
And sixthly, correcting the initial inter-city passenger flow generation amount of the traffic cell: respectively calculating and obtaining the corrected traffic cell intercity passenger flow generation amount G according to a formula (10) and a formula (11)kInter-city passenger flow attraction amount Ak;
In the formulas (10) and (11), n is the number of traffic zones,
the average reachability is the average value of all cell reachability in each circle of layers.
The method for improving the accuracy of the intercity passenger flow data of the traffic model and the city is suitable for the traffic district partition with small granularity, and can efficiently and accurately acquire real-time data by combining the large historical population passenger flow data, thereby providing accuracy guarantee for the refined intercity passenger flow prediction.
Example 4:
a method for improving the inter-city passenger flow data early warning of a traffic model with a city as shown in the attached figure 3 comprises the following steps:
firstly, acquiring basic data: study of traffic in citiesPopulation POP of cell kkAnd employment data EMPkPopulation POP of different circle layers i (core area, main city area and peripheral area)iAnd number of employment EMPi(ii) a Current passenger flow Q of different circle layers i and j between citiesijAnd Qji(ii) a The data are generally obtained by traditional resident trip investigation or statistical departments of relevant cities in the urban traffic model, but the acquisition of the resident trip investigation data is difficult to break through the administrative boundary barrier and cannot provide support for the regional traffic model, and the big data technology provides possibility for acquiring data of intercity outgoing amount, population and employment posts.
The specific steps for acquiring the population employment data of each cell (or each circle layer) are as follows: the method comprises the steps of firstly obtaining the resident population and the working population of a unit grid unit (for example, 200 x 200 meters) according to Internet positioning data, and then associating the grid population with the boundaries of traffic cells (or all circles of layers) to obtain the resident population and the employment position number of each traffic cell (or all circles of layers).
When the internet positioning data is acquired in real time, based on real-time statistics and prediction of historical big data, according to different passenger flow distribution base numbers of research cities, the peak time period, unit grid unit coordinates and threshold value ranges [ a, b ] of resident population and working population are set. When the resident population and the working population in the unit grid cell coordinate are higher than the highest threshold b, the unit grid cell can be provided with sub-grid cells, and the value range of the sub-grid cells can be adjusted in real time or periodically according to the resident population density, the working population number, the emergency events, the peak time period and the like of each cell, for example, the value range can be dynamically adjusted from 50 × 50 meters to 100 × 100 meters. When the population density is higher, the working population number is larger, and/or in a peak period, the unit grid unit sets the sub-grid more accurately, so that the positioning data acquisition accuracy is higher.
The specific steps for acquiring the current passenger flows of different circles among cities are as follows: firstly, establishing a matching relation between an urban circle layer and a user stop point by using internet positioning data, and then acquiring intercity travel passenger flow by identifying the flow direction of population;
intercity passenger flow Q based on current situationijAnd QjiCollecting and obtaining the current intercity passenger flow generation amount G of different circle layersiThe current situation of intercity passenger flow attraction AiWhere i, j ∈ { core region, primary metropolitan region, peripheral region };
Gi=Qij (1)
Ai=Qji (2)
secondly, calibrating the average intercity passenger flow rate (including generation rate and attraction rate) of each circle of layers: and calibrating the average intercity passenger flow trip rate of each circle layer by using the intercity passenger flow generation amount, the attraction amount, the population and employment data of different circle layers obtained in the first step. An intercity passenger flow generation model is constructed based on a generation rate method as follows:
in the formula (3), the reaction mixture is,
the average intercity passenger flow generation rate of the residential population and employment posts of the circle layer i is shown;
in the formula (4), the reaction mixture is,
the average intercity passenger flow attraction rate of the residential population and employment posts of the circle layer i;
thirdly, calculating the initial inter-city passenger flow generation amount of each traffic cell: calculating the initial intercity passenger flow generation amount of the cell k belonging to different circle layers by using the average intercity passenger flow trip rate of each circle layer obtained in the second step
Initial intercity passenger flow attraction
Fourthly, calibrating utility functions of ground traffic (including cars, taxis and passenger buses) and rail traffic (including intercity railways and subways);
s41: obtaining the proportion of the current situation that the local city cell k reaches the adjacent city cell g by adopting two travel modes of ground traffic (including cars, taxis and passenger buses) and rail traffic (including intercity railways and subways)
The rail transit passenger flow can be obtained by using railway ticket business or bus card swiping data, and the ground transit passenger flow can be obtained by subtracting the rail transit passenger flow from the current passenger flow.
S42: and (5) calibrating the utility function of the travel of the local city cell k to the selection mode m of the adjacent city cell g according to the formula (7) by combining the proportions of the travel of the modes obtained in the S41
Wherein, when m takes 1, the ground traffic is represented, and when m takes 2, the track traffic is represented:
in the formula (7), the reaction mixture is,
representing the traveling utility of ground traffic and rail traffic;
the time of the travel in the vehicle is,
is the travel time outside the automobile,
α
1、α
2is a calibrated parameter; the time variables in this step are current values;
s43: the parameters obtained in S42
α
1、α
2And planning the travel time of the year in the vehicle
And travel time outside vehicle
Substituting the formula (9) into the formula (9), and obtaining the proportion of travel of the planning year from the local city cell k to the adjacent city cell g in the selection mode m;
fifthly, constructing accessibility indexes: method for calculating accessibility according to opportunity accumulation and constructing accessibility index Rk;
Traffic reachability reflects the inherent link between the transportation system and land use and is a primary goal of traffic planning. Reachability is often used to assess the convenience of public transportation systems, or the ease with which a group of people can reach a common-place facility (e.g., hospital, park, school), or to study the vulnerability of a network with changes in reachability. At present, no research is available for introducing traffic accessibility indexes into an intercity passenger flow generation model.
The invention adopts the concept of cumulative-opportunity (cumulative-opportunity) to construct the reachability index suitable for predicting the generation amount of intercity passenger flow. The accumulated opportunity describes the number of opportunities (such as working posts) which can be developed by a traveler in contact with the traveler in a certain travel time range by using a certain transportation mode from a certain place. As shown in fig. 2, it is possible for a traveler to obtain all the opportunities for development as long as a given travel time is sufficiently long.
S51: calculating the chance number O of the neighbor cell g obtained from the cell k in the local city within the time threshold T according to the formula (8)k(T) obtaining the weighted sum of the opportunity numbers by adopting different trip modes;
in the formula (8), the reaction mixture is,
the table type local city cell k adopts the adjacent city opportunity number obtained by the mode m, and the opportunity can be referred to as population and employment post; the time threshold T is obtained by the quantile of the current intercity travel time; time of flight t
kgCalculated by traffic network and equal to travel time in vehicle
External travel time of car
The quantile value may be 95%.
S52: calculating a reachability index Rk: according to the concept of cumulative opportunity, RkDefined as the ratio of the number of available neighbor opportunities in cell k to the total number of available neighbor opportunities within time threshold T:
in formula (9), O (T)max) Indicating that the number of all opportunities that may be reached for a sufficiently long time is equal to the number of opportunities for all cells in the neighborhood.
And sixthly, correcting the initial inter-city passenger flow generation amount of the traffic cell: respectively calculating the corrected generation amount G of the intercity passenger flow of the traffic community according to a formula (10) and a formula (11)kInter-city passenger flow attraction amount Ak;
In the formulas (10) and (11), n is the number of traffic cells,
the average reachability is the average value of all cell reachability in each circle of layers.
And seventhly, performing short-term, medium-term and long-term early warning according to preset passenger flow generation amount and attraction amount. Generate the intercity passenger flow GkInter-city passenger flow attraction amount AkAnd comparing the average value with the historical period of the current day (for example, every week, every month and every year), correcting the value of a warning line by referring to the predicted conditions of holidays, important activities and the like, generating a passenger flow trend graph for early warning when the value exceeds the warning line, and reminding the short-term planning of public transport capacity, unreasonable traffic planning, emergency situations, long-term planning of city and population development and the like.
The embodiment is based on the same-urbanization intercity passenger flow generation model, is suitable for the traffic district partition with small granularity, can efficiently and accurately acquire real-time data by combining the large data of the historical population passenger flow, and provides accuracy guarantee for refined intercity passenger flow prediction.
The invention has been described in an illustrative manner, and it is to be understood that the invention is not limited to the specific embodiments described above, but is intended to cover various modifications, which may be made by the methods and technical solutions of the invention, or may be applied to other applications without modification.