CN102521998A - Method for optimizing emergency traffic evacuation path based on reliability under extraordinary disaster condition - Google Patents

Abstract

The invention discloses a method for optimizing an emergency traffic evacuation path based on reliability under an extraordinary disaster condition, and relates to a path optimization method. A central server receives an acquired remote sensing image, calculates an optimal evacuation path on line, and displays the optimal evacuation path on a vector electronic map of a disaster-hit area; and the optimal evacuation path is published to evacuation vehicles in real time in a communication way. The method is characterized in that: a remote-sensing-data-based road section travel time extraction module, a road network topology data updating module, and an emergency traffic evacuation path optimization module meeting requirements for safety and reliability are involved. By the method, the reliable extraction of road section travel time, the passage reliability of an evacuation path under the extraordinary disaster condition, and the safety and reliability of the evacuation path under the extraordinary disaster condition are ensured.

Description

Under the especially big hazardous condition based on the emergent traffic evacuation method for optimizing route of reliability

[technical field]

The present invention relates to a kind of method for optimizing route, more specifically relate to emergent traffic evacuation method for optimizing route under a kind of especially big hazardous condition.

[background technology]

The existing achievement in research overwhelming majority traffic evacuation path optimization problem of all will meeting an urgent need is equal to the calculating of graph theory middle distance shortest path; Think that merely implementing unidirectional green wave control scheme to each Emergency shelter apart from each crossing on the shortest route at the disaster scene just can realize emergency evacuation the most fast; This is a kind of idea wrong, has ignored the influence that the road traffic delay running status of suddenling change under the especially big hazardous condition produces the emergency evacuation vehicle fully.The core objective of emergent traffic evacuation is " safety, fast ", and what need to pay close attention to is that to evacuate the journey time of vehicle on emergent traffic evacuation path the shortest, considers factors such as current reliability that especially big disaster incident possibly cause, safe reliability simultaneously.

The patent No. is that 200710161193 " a kind of personnel evacuation method of municipal traffic under calamity outburst surroundings " at first set up the road net data structure on the basis that obtains and evacuate relevant information; Revise the road net data structure through the position of confirming disaster point then, improve algorithm design based on the max-flow of dynamic network stream at last and evacuate the path.There is following problem: 1) do not have to obtain channel with evacuating relevant dynamic information under the clear and definite disaster outburst surroundings, evacuate path journey time reliability and be difficult to guarantee; 2) do not consider of the influence of particularly serious disaster, evacuate the current reliability in path and be difficult to guarantee road network; 3) do not relate to the conflict analysis of emergency vehicles and other vehicles, evacuate the path safe reliability and be difficult to guarantee in the crossing.

[summary of the invention]

The present invention proposes under a kind of especially big hazardous condition the emergent traffic evacuation method for optimizing route based on reliability, and target is to satisfy the journey time reliability in emergent traffic evacuation path under the especially big hazardous condition, current reliability and safe reliability.

Information source is the devastated remote sensing images from unmanned plane, dirigible; Emergent traffic control center receives the remote sensing images of being gathered, and central server is installed emergent traffic evacuation path optimization software systems, on line computation and the Vector Electronic Map in the devastated, shows the optimum path of evacuating; Through communication modes such as VMS, on-vehicle navigation apparatus, frequency modulation broadcasting, Internet optimum is evacuated the path real-time release and give the evacuation vehicle.

Technological core of the present invention is emergent traffic evacuation path optimization software systems under the especially big hazardous condition, by forming based on Link Travel Time extraction module, the road network topology data update module of remotely-sensed data, the emergent traffic evacuation path optimization module that satisfies safe reliability.

Break through the application limitation of conventional traffic information acquisition mode under especially big hazardous condition based on the Link Travel Time extraction module of remotely-sensed data, guaranteed the reliable extraction of Link Travel Time; The road network topology data update module is used the dynamic topology rebuilding technology based on the road data incremental update, has guaranteed to evacuate under the especially big hazardous condition the current reliability in path; The module considering intersection traffic conflict of emergent traffic evacuation path optimization has guaranteed to evacuate under the especially big hazardous condition safe reliability in path to emergency evacuation vehicle operating Influence on security.

[description of drawings]

Fig. 1. block scheme of the present invention;

Fig. 2. Link Travel Time extraction module process flow diagram;

Fig. 3. road section length is calculated synoptic diagram;

Fig. 4. process flow diagram is estimated in the crossing queue length;

Fig. 5. road network topology Data Update process flow diagram under the especially big hazardous condition.

[embodiment]

Obtain the journey time data in each highway section in disaster origination point and the Emergency shelter overlay area road network through acquisition process to remotely-sensed data; Use the road network topology data update module and upgrade the Vector Electronic Map in the disaster overlay area; To minimize the travel time, to minimize the route complexity is optimization aim, is constraint condition satisfy to evacuate the path security, the compute optimal traffic evacuation path of meeting an urgent need.

1. based on the Link Travel Time extraction module of remotely-sensed data

Link Travel Time is a reflection road traffic flow running status traffic parameter the most intuitively, is the data basis of emergent traffic evacuation path optimization.The main flow means of current Link Travel Time collection are to be the fixed detection method of representative and the Floating Car detection method that is the basis with the inductive coil with GPS.Under especially big hazardous condition, fixed detecting device rapid wear difficulty is repaiied, and the gps data communication stability is difficult to guarantee, all can't guarantees the reliable collection of road network Link Travel Time on a large scale.This module is based on present stage ripe remote sensing images road data, information of vehicles extractive technique; Link Travel Time method for distilling based on remotely-sensed data has creatively been proposed; Guaranteed the reliability that Link Travel Time is extracted under the especially big hazardous condition; Shown in accompanying drawing 2, concrete steps are following:

Step1: extract road data based on remote sensing images;

Step2: calculate road section length based on the road data that is extracted;

The calculating of road section length is shown in accompanying drawing 3, and each grid is represented the remote sensing images pixel among the figure, and the grey grid is the road surface, gets the highway section with two points of lateral edges, and coordinate is respectively (x ₁, y ₁) and (x ₂, y ₂), unit all is pixel counts.The road section length of then representing with pixel count is converted into long measure rice again for

, and road section length is then arranged:

$l=\mathrm{zf}=f\sqrt{{(x_1-x_2)}^2+{(y_1-y_2)}^2}$

In the formula, f is the remote sensing images spatial resolution.

Step3: extract highway section vehicle number n_car based on remote sensing images;

Step4: estimate road section traffic volume density;

If the unidirectional number of track-lines in highway section is lane, then road section traffic volume density Estimation value is:

$k=\frac{n\_\mathrm{car}}{2l\×\mathrm{lane}}$

Step5: calculate the average running time

of vehicle on the highway section

The computing method of

are following:

$\stackrel{\‾}{v_s}=v_f(1-\frac{K}{K_j})$ The K value is normal

$\stackrel{\‾}{v_s}=v_m\mathrm{Ln}\left(\frac{K_j}{K}\right)$ The K value is bigger

$\stackrel{\‾}{v_s}=v_f{e}^{-\frac{k}{k_m}}$ The K value is less

In the formula, k is the estimated result of Step4; v _fBe free stream velocity, K _jBe jam density, v _mBe critical velocity, be the highway layout value.

$\stackrel{\‾}{T}=\frac{L}{\stackrel{\‾}{v_s}}$

In the formula, L is the result of calculation of Step2.

Step6: estimate the crossing queue length;

The Hough conversion is a straight line object of from the binary map that contains the vehicle object, finding out the vehicle element aggregation; The two ends of the straight line that obtains after the process Hough conversion all are that the pixel value is 1 vehicle element; The present invention proposes a kind of crossing queue length based on the Hough conversion and estimates flow process; Shown in accompanying drawing 4, concrete operations are: an end of the straight-line segment that obtains along the Hough conversion begins, and begins once to check the value of each pixel along straight line; The value of not being interrupted continuously is that 1 pixel group is a vehicle object; The value of not being interrupted continuously is that 0 pixel group then is a convoy spacing, and the continuously uninterrupted value that goes out along this straight-line detection at last is that the number of 1 object is this fleet's queue length, also can use continuously uninterrupted value be the object number of 0 pixel group add 1 be this fleet queue length.

Step7: " queue length " variable of using in delay Model Calculation crossing mean delay

model that provides among the HCM2000 is the estimated result of Step6;

Step8: with what obtain among the Step5

With obtain among the Step6

Addition is Link Travel Time T _Ij

2. road network topology data update module

Most especially big disaster incidents all can cause the sudden change of road reliability; Extraordinary serious natural calamities incident such as with the earthquake being representative may directly be destroyed road and affiliated facility thereof, causes subregion, city road network or intra-zone branch highway section to be open to traffic; Especially big meteorological disasters such as heavy rain, severe snow, typhoon can cause city part road section capacity to completely lose when serious; Hazardous chemical, toxic gas, radiomaterial leakage etc. directly injure the production incident of human body in case take place, and the regional road network in the certain hour section in the incident coverage can't use etc. fully.Ignore the often approach highway section that can't be open to traffic, the resulting emergent traffic evacuation of above-mentioned variation path, cause evacuating decrease in efficiency, the panic degree aggravation of evacuee.This module based on present stage ripe remote sensing images road damage detection technique, all kinds of meteorological disaster detecting sensor, based on the dynamic topology rebuilding technology of road data incremental update; Road network topology Data Update flow process under the especially big hazardous condition has been proposed; Guaranteed to evacuate under the especially big hazardous condition the current reliability in path, shown in accompanying drawing 5.

3. satisfy the emergent traffic evacuation path optimization module of safe reliability

The emergency evacuation vehicle is aspect trip process safe reliability path optimization must consider under the especially big hazardous condition.Reason from the accident sees that the traffic conflict that the crossing takes place accounts for space of top prominence.Under the especially big hazardous condition and since Psychological Panic cause unordered degree aggravation that the public goes on a journey and the afoul traffic flow of emergency evacuation vehicle heading be influence the emergency evacuation vehicle can be safely principal element through the crossing.

Under the especially big hazardous condition emergency evacuation vehicle optimal path confirm to receive influence of various factors, be the result under the multifactor synergy, show multiple goal property and multiattribute characteristics.Resultant reliable Link Travel Time data in the Link Travel Time extraction module of this module application based on remotely-sensed data; Based on upgrading the resultant reliable road network topology data in back in the road network topology data update module base, set up the emergency evacuation vehicle route Optimization Model that satisfies safe reliability.The objective function of path optimization is chosen as and minimizes the travel time, minimizes the route complexity, and satisfies the constraint condition of evacuating the path security.

$\left\{\begin{array}{c}G=\left\{\begin{array}{c}\mathrm{Min}{f}_1=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{T}_{\mathrm{ij}}{x}_{\mathrm{ij}}\\ \mathrm{Min}{f}_2=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{x}_{\mathrm{ij}}\end{array}\right.\\ s.t.:\left\{\begin{array}{c}{\mathrm{SI}}_k=\underset{m_k}{\mathrm{\Σ}}{\mathrm{SI}}_{m_k}=N\underset{m_k}{\mathrm{\Σ}}\underset{n}{\mathrm{\Σ}}{\mathrm{CI}}_n\\ {\mathrm{ST}}_k\≥{\mathrm{SI}}_{\min }\\ x_{\mathrm{ij}}=\mathrm{0,1}\\ i=\mathrm{1,2},...,n;j=\mathrm{1,2},...,n\end{array}\right.\end{array}\right.$

In the model: T _IjBe i in the road network topology structure, the journey time of corresponding road section between the j node; x _Ij=0 or 1, x wherein _Ij=1 expression i, between the j node corresponding road section on selected evacuation path, x _Ij=0 expression i, corresponding road section is not on selected evacuation path between the j node; SI _MinBe the minimum safe degree;

Degree of safety for the crossing of path k process; m _kCrossing quantity for path k process; CI _nBe the index conflict parallel, vertical, that Reverse Commuting is corresponding; N is the average seating capacity of emergency vehicles.

Claims (4)

1. Under the especially big hazardous condition based on the emergent traffic evacuation method for optimizing route of reliability, receive the remote sensing images of being gathered by central server, on line computation and Vector Electronic Map, show the optimum path of evacuating in the devastated; Through communication modes optimum is evacuated the path real-time release and give to evacuate vehicle, the emergent traffic evacuation path optimization module that its characteristic comprises Link Travel Time extraction module, the road network topology data update module based on remotely-sensed data and satisfies safe reliability is formed;

   The concrete job step of Link Travel Time extraction module based on remotely-sensed data is following:

   Step1: extract road data based on remote sensing images;

   Step2: calculate road section length based on the road data that is extracted;

   Step3: extract highway section vehicle number n_car based on remote sensing images;

   Step4: estimate road section traffic volume density;

   Step5: calculate the average running time of vehicle on the highway section

   Step6: estimate the crossing queue length;

   Step7: " queue length " variable of using in delay Model Calculation crossing mean delay model that provides among the HCM2000 is the estimated result of Step6;

   Step8: with what obtain among the Step5

   

   With obtain among the Step6

   

   Addition is Link Travel Time T _Ij

   The road network topology data update module based on present stage ripe remote sensing images road damage detection technique, all kinds of meteorological disaster detecting sensor, based on the dynamic topology rebuilding technology of road data incremental update, road network topology Data Update flow process under the especially big hazardous condition has been proposed;

   Satisfy resultant reliable Link Travel Time data in the Link Travel Time extraction module of emergent traffic evacuation path optimization's module application based on remotely-sensed data of safe reliability; Based on upgrading the resultant reliable road network topology data in back in the road network topology data update module base; The emergency evacuation vehicle route Optimization Model of safe reliability is satisfied in foundation; The objective function of path optimization is chosen as and minimizes the travel time, minimizes the route complexity, and satisfies the constraint condition of evacuating the path security.
2. 2. based on the emergent traffic evacuation method for optimizing route of reliability, it is characterized in that under the especially big hazardous condition according to claim 1: based on the Step4 of the Link Travel Time extraction module of remotely-sensed data: estimate road section traffic volume density;

   If the unidirectional number of track-lines in highway section is lane, then road section traffic volume density Estimation value is:

   $k=\frac{n\_\mathrm{car}}{2l\×\mathrm{lane}}$
3. According under claim 1 and the 2 described especially big hazardous condition based on the emergent traffic evacuation method for optimizing route of reliability, it is characterized in that: based on the Step5 of the Link Travel Time extraction module of remotely-sensed data: calculate the average running time

   

   of vehicle on the highway section

   The computing method of

   

   are following:

   $\stackrel{\‾}{v_s}=v_f(1-\frac{K}{K_j})$ The K value is normal

   $\stackrel{\‾}{v_s}=v_m\mathrm{Ln}\left(\frac{K_j}{K}\right)$ The K value is bigger

   $\stackrel{\‾}{v_s}=v_f{e}^{-\frac{k}{k_m}}$ The K value is less

   In the formula, k is the estimated result of Step4; v _fBe free stream velocity, K _jBe jam density, v _mBe critical velocity, be the highway layout value,

   $\stackrel{\‾}{T}=\frac{L}{\stackrel{\‾}{v_s}}$

   In the formula, L is the result of calculation of Step2.
4. According under claim 1 and the 2 described especially big hazardous condition based on the emergent traffic evacuation method for optimizing route of reliability; It is characterized in that: based on the Step6 of the Link Travel Time extraction module of remotely-sensed data: estimate that the crossing queue length is: an end of the straight-line segment that obtains along the Hough conversion begins; Begin once to check the value of each pixel along straight line; The value of not being interrupted continuously is that 1 pixel group is a vehicle object; The value of not being interrupted continuously is that 0 pixel group then is a convoy spacing, and the continuously uninterrupted value that goes out along this straight-line detection at last is that the number of 1 object is this fleet's queue length.

Images