CN104899654A - Path selecting method for alleviating rail transit jam - Google Patents

Abstract

The invention discloses a path selecting method for alleviating a rail transit jam. According to the method, based on a minimal cost path algorithm and a shortest path algorithm, 'transfer station pairs' needed to provide path selecting information are positioned by sequencing going-out costs out of the total amount of all the transfer station pairs in a descending order; furthermore, a small part of passengers of the positioned 'transfer station pairs' are selected and the path selecting information is provided for the passengers to guide the passengers to select the minimal going-out cost path, so that the rail transit jam is alleviated. By virtue of changing the paths of the small part of passengers, the rail transit jam can be effectively alleviated just by slightly increasing the going-out time of a small quantity of passengers. Moreover, the required effect can be achieved just by issuing path suggestion information on a few of stations. The path selecting information obtained by using the method can be issued by virtue of information transmitting media, such as TVs, broadcasts, message signs, official websites and microblogs. The method is simple and feasible and easy to operate if being applied.

Description

A kind of for alleviating the crowded routing resource of track traffic

Technical field

The present invention relates to a kind of for alleviating the crowded routing resource of track traffic.

Background technology

Urban track traffic, as the one in public trip mode, in occupation of critical role in present Urban Traffic, carries increasing traffic task.But due to the imbalance of traffic supply and demand, traffic congestion phenomenon takes place frequently.In subway network, between each circuit there is notable difference in handling capacity of passengers, not only causes the waste of subway transport capacity resource, also reduces the trip quality of passenger.In order to improve the utilization to track traffic transport capacity resource, alleviate urban track traffic crowded, effectively guide passenger safety, convenient, take track traffic fast, many cities start to set up track traffic information issuing system.But these track traffic information issuing systems still have the following disadvantages at present:

1) the real-time passenger flow situation of track traffic is issued in current most track traffic information issuing system timing, independently select traffic path crowded to evade by passenger, exist Information issued not in time, the problem such as routing suggestion of intelligence, the limited use of crowded optimization cannot be provided;

2) in the track traffic information issuing system improved, flexible arrangement information can be changed according to the volume of the flow of passengers and issue interval, phase commuter rush hour shortens information issuing time interval, in time for passenger provides congestion information, but passenger's routing or autonomous decision, effectively could not guide the selection of passenger route, still can only carry out part optimization to crowded state;

3) current, although also occurred that track traffic information issuing system provides routing to advise for passenger, but can only according to passenger flow situation at that time for passenger provides so-called optimal path, passenger is guided to select not crowded interval in a large number, easily cause original not crowded interval to become crowded, thus the path that part passenger is selected is no longer optimal path because the impact of other passenger flow becomes;

In sum, existing urban track traffic information issuing system or just issue real-time passenger flow situation, independently selects traffic path by passenger; According to real-time passenger flow situation for passenger provides traffic path, but fail to consider influencing each other between passenger flow.In existing track traffic information issuing system, routing resource all can only carry out part optimization to track traffic congestion, also there is very large improvement space.

Summary of the invention

The invention provides a kind of for alleviating the crowded routing resource of track traffic, the method is based on water channel principium algorithm and shortest path first, orient by the crowded a few passengers had the greatest impact of track traffic, and provide path advisory information to this part passenger, and then guide passenger to select suitable path, just can alleviate track traffic preferably crowded, improve the utilization to transport capacity resource.

For alleviating the crowded routing resource of track traffic, first, to the passenger in Rail traffic network all according to shortest-path method Selecting Travel Paths, the extra Trip Costs of all passengers in Rail traffic network is calculated; Then, the outer Trip Costs of total value in Rail traffic network between any two transfer stops is calculated; Then, sort according to order from big to small to the outer Trip Costs of the total value that all transfer stops are right, location needs the transfer stop pair providing routing information; Finally, according to oriented transfer stop to information for passenger provides routing information, the passenger that the extra Trip Costs of the passenger that oriented transfer stop is right comes front P% selects water channel principium method trip route, and all the other all passengers select shortest-path method Selecting Travel Paths;

Wherein, described Rail traffic network is made up of fillet between node and node, and described node refers to the station in Rail traffic network, and the fillet between described node and node refers to the block section between stations of Rail traffic network;

The Trip Costs c of described passenger in Rail traffic network on every section of block section between stations _ij(f _ij) refer to the travel time cost that the j that i stands adjacent stands and congestion costs sum:

$c_{\mathrm{ij}}\left(f_{\mathrm{ij}}\right)=(1+\mathrm{\α}{\left(\frac{f_{\mathrm{ij}}}{M_{\mathrm{ij}}}\right)}^{\mathrm{\β}})t_{\mathrm{ij}}=t_{\mathrm{ij}}+\mathrm{\α}{\left(\frac{f_{\mathrm{ij}}}{M_{\mathrm{ij}}}\right)}^{\mathrm{\β}}{t}_{\mathrm{ij}}$

Wherein, f _ijand M _ijbe illustrated respectively in the volume of the flow of passengers from station i to adjacent station j in a hour and rated capacity, t _ijrepresent the travel time at the j station that i stands adjacent, α represents congestion costs linear dimensions, and span is that 0.15 ~ 0.45, β represents congestion costs index parameters, and span is 1 ~ 10;

The extra Trip Costs ce of described passenger in Rail traffic network on every section of track section _ij(f _ij) refer to the congestion costs sum that the j that i stands adjacent stands:

${\mathrm{ce}}_{\mathrm{ij}}\left(f_{\mathrm{ij}}\right)=\mathrm{\α}{\left(\frac{f_{\mathrm{ij}}}{M_{\mathrm{ij}}}\right)}^{\mathrm{\β}}{t}_{\mathrm{ij}}$

The extra Trip Costs of described passenger in transportation network utilizes shortest-path method to distribute to obtain the trip route of passenger, based on passenger process path in extra Trip Costs sum on every section of block section between stations comprising.

The outer Trip Costs C of total value in described Rail traffic network between any two transfer stops _erefer to the summation of the extra Trip Costs of all passengers through these two transfer stops;

The right quantity N in the transfer stop that described location needs to provide routing information is determined by average additional passengers number F:

First, when making all passengers select water channel principium to go on a journey, obtain average additional passengers number F ₀;

Then, N is increased gradually from 0, when meeting 1.00F ₀<F (N) <1.10F ₀obtain the value of N, F (N) represents that all passengers coming the transfer stop of front N right through the outer Trip Costs of total value use least cost routing Selecting Travel Paths, when remaining all passengers with critical path method (CPM) Selecting Travel Paths, and the average additional passengers number of Rail traffic network;

Described average additional passengers number refers to that the additional passengers number of track block section between stations is divided by track block section between stations sum, and described additional passengers number refers to the passengers quantity exceeding vehicle rated passenger capacity;

Described P is determined by average additional passengers number F:

First, all passengers right when the transfer stop through location select water channel principium, and when all selecting shortest path without all passengers that the transfer stop of location is right, the average additional passengers number obtained is F ₁;

Secondly, P is increased gradually from 0, when meeting 1.00F ₁<F (P) <1.10F ₁time, obtain the value of P.

The described Trip Costs sum with all track sections is formed the total Trip Costs of Rail traffic network and is reached minimum, and distribute the magnitude of traffic flow on every section of track in Rail traffic network, concrete steps are as follows:

Step 1: make iterations n=1, based on travel time t _ij, utilize dijkstra's algorithm to distribute the magnitude of traffic flow of each track section, obtain the volume of the flow of passengers f of each track section _ij;

Step 2: based on the volume of the flow of passengers of each track section, calculates the Trip Costs of every section of track section, and obtains the Trip Costs conversion value of every section of track section according to following formula ${\tilde{c}}_{\mathrm{ij}}\left(f_{\mathrm{ij}}\right)=c_{\mathrm{ij}}\left(f_{\mathrm{ij}}\right)+f_{\mathrm{ij}}\frac{{\mathrm{dc}}_{\mathrm{ij}}\left(f_{\mathrm{ij}}\right)}{{\mathrm{df}}_{\mathrm{ij}}};$

Step 3: the Trip Costs conversion value of the every section of track section obtained with step 2, adopts dijkstra's algorithm to distribute the track magnitude of traffic flow, obtains the volume of the flow of passengers intermediateness value g of every section of track section _ij;

Step 4: determine iteration step length λ, λ meets formula $\mathrm{\&Sigma;}({g_{\mathrm{ij}}}^n-{f_{\mathrm{ij}}}^n)\&times;{\tilde{c}}_{\mathrm{ij}}({f_{\mathrm{ij}}}^n+\mathrm{\&lambda;}({g_{\mathrm{ij}}}^n-{f_{\mathrm{ij}}}^n))\&times;t_{\mathrm{ij}}=0,$ G _ij ⁿand f _ij ⁿbe illustrated respectively in the volume of the flow of passengers intermediateness value and the iterative value that obtain track section in the process that changes for n-th time;

Step 5: determine new iteration starting point: f _ij ⁿ⁺¹=f _ij ⁿ+ λ (g _ij ⁿ-f _ij ⁿ);

Whether no step 6: test for convergence, judge the volume of the flow of passengers of every section of track section in the n-th sub-distribution and volume of the flow of passengers change of the (n+1)th sub-distribution, namely whether meet formula ε for judge the factor, ε <10 ^-3if meet formula, then stop iteration, with the volume of the flow of passengers iterative value dispense path on current every section track section; Otherwise, return step 2, with f _ij ⁿ⁺¹recalculate the Trip Costs of every section of track section.

Realize water channel principium, make total Trip Costs of whole track traffic minimum.

Beneficial effect

The invention provides a kind of for alleviating the crowded routing resource of track traffic, the method is based on water channel principium algorithm and shortest path first, by sorting according to order from big to small to the outer Trip Costs of total value of all " transfer stop to ", location needs to provide " transfer stop to " of routing information; And then, choose small part and provide routing information through the passenger of " transfer stop to " of location and for this part passenger, guide passenger to select minimum Trip Costs path, thus it is crowded to alleviate track traffic.To the routing resource than ever based on passenger, the routing resource that the present invention proposes is based on website, and only need issuing a small amount of routing information on a few website, just can effectively to alleviate track traffic crowded, has stronger specific aim and feasibility.Such as, in the present invention, only need to select information at 10 website issuing paths, just can effectively alleviate Beijing Metro network congestion.The routing information utilizing the method to draw can be issued by information medias such as TV, broadcast, message board, official website and microbloggings, should use simple possible, be easy to operation.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of the method for the invention;

The extra Trip Costs C of Fig. 2 _edistribution plan, wherein, the distribution plan that the extra Trip Costs that (a) is subway network " transfer stop to " sorts from big to small, (b) is the statistical Butut of the extra Trip Costs of iron network " transfer stop to ";

The effect of optimization exploded view that " transfer stop to " quantity N that Fig. 3 chooses the is corresponding and position distribution of transfer stop of routing information is provided, wherein, a () is for average additional passengers number is with the change curve of " transfer stop to " the quantity N chosen, (b) for average travel cost is with the change curve of " transfer stop to " the quantity N chosen, (c) position for the transfer stop of routing information need be provided residing in subway network;

Fig. 4 carrys out effect of optimization exploded view corresponding to the trip proportion P of selecting paths according to the routing information that infosystem provides, and wherein, (a), for average additional passengers number is with the change curve of P, (b) is for average travel cost is with the change curve of P.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail, but not as a limitation of the invention.

For alleviating the crowded routing resource of track traffic, as shown in Figure 1, first, to the passenger in Rail traffic network all according to shortest-path method Selecting Travel Paths, the extra Trip Costs of all passengers in Rail traffic network is calculated; Then, the outer Trip Costs of total value in Rail traffic network between any two transfer stops is calculated; Then, sort according to order from big to small to the outer Trip Costs of the total value that all transfer stops are right, location needs the transfer stop pair providing routing information; Finally, according to oriented transfer stop to information for passenger provides routing information, the passenger that the extra Trip Costs of the passenger that oriented transfer stop is right comes front P% selects water channel principium method trip route, and all the other all passengers select shortest-path method Selecting Travel Paths; Thus it is crowded to alleviate track traffic;

Concrete steps are as follows:

The present invention is based on track traffic brushing card data prediction peak hour OD to measure.Brushing card data have recorded the time that each passenger is entered the station and set off, and therefore can obtain volume of traffic distribution plan in time according to brushing card data, thus obtain the time interval of morning peak and evening peak, and then intercept out the OD of morning peak and evening peak.

The first step: build Beijing Metro network and predict Beijing Metro peak hour OD;

Find Beijing Metro website and annexation thereof from Beijing Metro official website, then use Google Earth (Google Maps) software to obtain each station geographic coordinate (comprising longitude and latitude); Collect each block section between stations information, comprise starting point, terminal, travel time and direction; Be shape (map graph) file by node and block section between stations convert information, thus create Beijing Metro network.

Based on Beijing Metro brushing card data, prediction Beijing Metro morning peak and the travel amount of evening peak, be respectively 2,028,440 trips/hour and 1,692,770 to go on a journey/hour.

Second step: distribute traffic flow the extra Trip Costs calculated between each transfer stop;

According to shortest-path method distribute traffic flow, calculate the extra Trip Costs of all passengers in Rail traffic network.

Calculate the outer Trip Costs of total value (passing through the cumulative of the extra Trip Costs of all passengers of these two transfer stops) in Beijing Metro network between any two transfer stops; Then, the outer Trip Costs of total value of all " transfer stop to " (two transfer websites) is sorted according to order from big to small.In Fig. 2, (a) represents distribution plan that the outer Trip Costs of the total value of " transfer stop to " sorts from big to small (first 50 " transfer stop to "); The extra Trip Costs that b () shows " transfer stop to " obeys power-law distribution, namely " transfer stop to " of small part occupies most extra Trip Costs, as, the outer Trip Costs of total value of front ten " transfer stop to " just accounts for 23.2% of the outer Trip Costs of whole subway network total value.

3rd step: location needs the transfer stop providing routing information;

Choose a small amount of transfer stop, provide routing information in these transfer stops, guide passenger to select suitable path, alleviate track traffic crowded.

Choose and provide effect of optimization that " transfer stop to " quantity N of routing information is corresponding as Fig. 3.In Fig. 3, (b) shows to choose " transfer stop to " that the outer Trip Costs of total value comes front ten, for providing water channel principium information through all passengers (accounting for 5% of total travel amount) of these ten " transfer stops to ", the average travel cost of network just can be made to drop to approximate minimum.And (a) shows, the average additional passengers number of whole network be reduced, need for more " transfer stop to " provides routing information.When choosing 50 " transfer stop to " (accounting for 15% of total travel amount), meet 1.00F ₀<F (N) <1.10F ₀.Wherein F ₀for the average additional passengers number of Rail traffic network when all passengers select water channel principium, dotted line in corresponding diagram.

After choosing " transfer stop to ", next statistics needs the transfer website providing routing information.If chosen front ten " transfer stops to ", then only need at international trade station, station, West Second Qi and Huo Yingzhan provide routing information, wherein, international trade station need provide 6 paths to select information, station, West Second Qi need provide 3 paths to select information, and Huo Yingzhan need provide 1 paths to select information.Figure (c) represents when choosing 50 " transfer stop to ", need provide the position that 10 of routing information websites (comprising the routing information quantity provided required for each website) are residing in subway network.

4th step: localization part needs the passenger providing routing information

In actual applications, it is very large that the routing information allowing all passengers through " transfer stop to " that the 3rd step is located all provide according to infosystem carrys out selecting paths difficulty, and the routing information that Fig. 3 illustrates to be provided according to infosystem carrys out effect of optimization corresponding to the trip proportion P of selecting paths.The P=0.3 passenger that namely extra Trip Costs comes front 30% in the passenger of " transfer stop to " through location uses water channel principium dispense path, remains all passenger (comprising the passenger of " transfer stop to " without location) and uses shortest path dispense path.As shown in Figure 4, the effect of optimization of similar P=1 can just be reached during P=0.3.

Claims (2)

1. for alleviating the crowded routing resource of track traffic, it is characterized in that, first, to the passenger in Rail traffic network all according to shortest-path method Selecting Travel Paths, calculating the extra Trip Costs of all passengers in Rail traffic network; Then, the outer Trip Costs of total value in Rail traffic network between any two transfer stops is calculated; Then, sort according to order from big to small to the outer Trip Costs of the total value that all transfer stops are right, location needs the transfer stop pair providing routing information; Finally, according to oriented transfer stop to information for passenger provides routing information, the passenger that the extra Trip Costs of the passenger that oriented transfer stop is right comes front P% selects water channel principium method trip route, and all the other all passengers select shortest-path method Selecting Travel Paths;

Wherein, described Rail traffic network is made up of fillet between node and node, and described node refers to the station in Rail traffic network, and the fillet between described node and node refers to the block section between stations of Rail traffic network;

The Trip Costs c of described passenger in Rail traffic network on every section of block section between stations _ij(f _ij) refer to the travel time cost that the j that i stands adjacent stands and congestion costs sum:

$c_{\mathrm{ij}}\left(f_{\mathrm{ij}}\right)=(1+\mathrm{\&alpha;}{\left(\frac{f_{\mathrm{ij}}}{M_{\mathrm{ij}}}\right)}^{\mathrm{\&beta;}})t_{\mathrm{ij}}=t_{\mathrm{ij}}+\mathrm{\&alpha;}{\left(\frac{f_{\mathrm{ij}}}{M_{\mathrm{ij}}}\right)}^{\mathrm{\&beta;}}{t}_{\mathrm{ij}}$

Wherein, f _ijand M _ijbe illustrated respectively in the volume of the flow of passengers from station i to adjacent station j in a hour and rated capacity, t _ijrepresent the travel time at the j station that i stands adjacent, α represents congestion costs linear dimensions, and span is that 0.15 ~ 0.45, β represents congestion costs index parameters, and span is 1 ~ 10;

The extra Trip Costs ce of described passenger in Rail traffic network on every section of track section _ij(f _ij) refer to the congestion costs sum that the j that i stands adjacent stands:

${\mathrm{ce}}_{\mathrm{ij}}\left(f_{\mathrm{ij}}\right)=\mathrm{\&alpha;}{\left(\frac{f_{\mathrm{ij}}}{M_{\mathrm{ij}}}\right)}^{\mathrm{\&beta;}}{t}_{\mathrm{ij}}$

The extra Trip Costs of described passenger in transportation network utilizes shortest-path method to distribute to obtain the trip route of passenger, based on passenger process path in extra Trip Costs sum on every section of block section between stations comprising.

The outer Trip Costs C of total value in described Rail traffic network between any two transfer stops _erefer to the summation of the extra Trip Costs of all passengers through these two transfer stops;

The right quantity N in the transfer stop that described location needs to provide routing information is determined by average additional passengers number F:

First, when making all passengers select water channel principium to go on a journey, obtain average additional passengers number F ₀;

Then, N is increased gradually from 0, when meeting 1.00F ₀<F (N) <1.10F ₀obtain the value of N, F (N) represents that all passengers coming the transfer stop of front N right through the outer Trip Costs of total value use least cost routing Selecting Travel Paths, when remaining all passengers with critical path method (CPM) Selecting Travel Paths, and the average additional passengers number of Rail traffic network;

Described average additional passengers number refers to that the additional passengers number of track block section between stations is divided by track block section between stations sum, and described additional passengers number refers to the passengers quantity exceeding vehicle rated passenger capacity;

Described P is determined by average additional passengers number F:

First, all passengers right when the transfer stop through location select water channel principium, and when all selecting shortest path without all passengers that the transfer stop of location is right, the average additional passengers number obtained is F ₁;

Secondly, P is increased gradually from 0, when meeting 1.00F ₁<F (P) <1.10F ₁time, obtain the value of P.

2. according to claim 1 a kind of for alleviating the crowded routing resource of track traffic, it is characterized in that, the described Trip Costs sum with all track sections is formed the total Trip Costs of Rail traffic network and is reached minimum, distribute the magnitude of traffic flow on every section of track in Rail traffic network, concrete steps are as follows:

Step 1: make iterations n=1, based on travel time t _ij, utilize dijkstra's algorithm to distribute the magnitude of traffic flow of each track section, obtain the volume of the flow of passengers f of each track section _ij;

Step 2: based on the volume of the flow of passengers of each track section, calculates the Trip Costs of every section of track section, and obtains the Trip Costs conversion value of every section of track section according to following formula

Step 3: the Trip Costs conversion value of the every section of track section obtained with step 2, adopts dijkstra's algorithm to distribute the track magnitude of traffic flow, obtains the volume of the flow of passengers intermediateness value g of every section of track section _ij;

Step 4: determine iteration step length λ, λ meets formula $\mathrm{\&Sigma;}({g_{\mathrm{ij}}}^n-{f_{\mathrm{ij}}}^n)\&times;{\tilde{c}}_{\mathrm{ij}}({f_{\mathrm{ij}}}^n+\mathrm{\&lambda;}({g_{\mathrm{ij}}}^n-{f_{\mathrm{ij}}}^n))\&times;t_{\mathrm{ij}}=0,{g_{\mathrm{ij}}}^n$ with $\mathrm{\&Sigma;}({g_{\mathrm{ij}}}^n-{f_{\mathrm{ij}}}^n)\&times;{\tilde{c}}_{\mathrm{ij}}({f_{\mathrm{ij}}}^n+\mathrm{\&lambda;}({g_{\mathrm{ij}}}^n-{f_{\mathrm{ij}}}^n))\&times;t_{\mathrm{ij}}=0,{g_{\mathrm{ij}}}^n$ Be illustrated respectively in the volume of the flow of passengers intermediateness value and the iterative value that obtain track section in the process that changes for n-th time;

Step 5: determine new iteration starting point: ${f_{\mathrm{ij}}}^{n+1}={f_{\mathrm{ij}}}^n+\mathrm{\&lambda;}({g_{\mathrm{ij}}}^n-{f_{\mathrm{ij}}}^n);$

Whether no step 6: test for convergence, judge the volume of the flow of passengers of every section of track section in the n-th sub-distribution and volume of the flow of passengers change of the (n+1)th sub-distribution, namely whether meet formula ε for judge the factor, ε <10 ^-3if meet formula, then stop iteration, with the volume of the flow of passengers iterative value dispense path on current every section track section; Otherwise, return step 2, with f _ij ⁿ⁺¹recalculate the Trip Costs of every section of track section.