CN103106812A - Method obtaining sea ship system average collision risks - Google Patents

Abstract

The invention discloses a method obtaining sea ship system average collision risks. The method includes: layering and simplifying a topological structure of the whole sea intelligent transport network at one moment through a reduction algorithm based on hierarchical clustering, eliminating ships without consideration of collision risks, basing the collision risks of collision preventation systems of two ships, and obtaining system collision risks from subsystems to the whole sea transport network through a weighted average fusion method from bottom to top.

Description

A kind of method of obtaining the average risk of collision of marine ships system

Technical field

The invention belongs to infotech and navigational field, particularly relate to a kind of method of obtaining the average risk of collision of marine ships system.

Background technology

Along with the prosperity and development of global trade, the marine ships magnitude of traffic flow increases day by day, so the also obviously increase thereupon of the internal risks of marine ships traffic system, thereby causes the complexity of marine intelligent traffic administration system and pressure also day by day to show especially.Marine intelligent transportation network is the dynamic network that comprises a large amount of boats and ships, occupies significant proportion in the traffic hazard at sea of its collision accident, annual because of its economic loss that causes and casualties very large.Therefore, to the ship collision risk in marine intelligent transportation network effectively identify, assessment and risk control management seems extremely important.

The research of the Collision Risk Index in marine intelligent transportation network has obtained numerous researchers' concern, and the Advanced Information Processing Techniques such as application fuzzy theory, information fusion and neural network have obtained some useful achievements in research.The scheme of the Ship ' Risk-Degree of Collision that is generally adopted by people at present is: each collision prevention ship is with from as standard, based on DCPA and TCPA and some other factors obtain the target boats and ships to the Risk-Degree of Collision of this ship separately.Therefore, calculating the method research of Risk-Degree of Collision mainly carries out from Ship Controling person's angle, from the measurement of microcosmic point to risk of collision, be difficult to satisfy maritime sector in the demand of carrying out on macroanalysis and global decisions, simultaneously single (two ships) Risk-Degree of Collision definition does not possess the risk ability of Direct function description system (macroscopic view) aspect.Also have some documents to provide research to whole marine site ship collision risk, but risk wherein is based on the research that the statistic of ship's navigation data is for many years carried out, and is system's risk of collision of a long period yardstick meaning.System's risk of collision that maritime sector needs in global decisions is time scale shorter ' immediately ' system risk, namely the content of our invention.

Up to the present, not yet see the report of the relevant system's risk of collision of obtaining marine intelligent transportation network that the present invention relates to.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art, a kind of method of obtaining the average risk of collision of marine ships system is provided.

The objective of the invention is to be achieved through the following technical solutions: a kind of method of obtaining the average risk of collision of marine ships system, the method comprises the steps:

(1) obtain the AIS data of a period of time: the standard A IS data of obtaining the maritime traffic of a period of time from boats and ships VTS system; Extract the data of following field: mmsi, shipname, sog, cog, heading, lon, lat and f_update_time.

The aeronautical data of a certain each boats and ships of sampling instant of marine ships AIS extracting data that (2) obtain from step 1.

(3) data that step 2 obtained are carried out hierarchical clustering and are divided classification.

(4) the some classes to obtaining in step 3, carry out the layering abbreviation.

(5) the every straton system to obtaining in step 4, calculate its system's risk of collision.

(6) judge system's risk of collision of marine intelligent transportation network: f according to result ₁During 〉=f, think that whole marine intelligent transportation network on-demand system risk of collision is larger, f ₁During＜f, think that the on-demand system risk of collision of whole marine intelligent transportation network is less; Wherein, f is risk threshold value.

The invention has the beneficial effects as follows: can carry out the collision at sea risk assessment for maritime sector according to system's risk of collision value of the marine intelligent transportation network that obtains, the whole risk of collision that reduces marine intelligent transportation network provides decision-making foundation.

Description of drawings

Fig. 1 is the hierarchical tree schematic diagram that bee-line method cluster obtains;

Fig. 2 is by threshold value layering result schematic diagram after bee-line method cluster;

Fig. 3 is marine intelligent transportation network abbreviation result schematic diagram.

Embodiment

Describe the present invention in detail below in conjunction with accompanying drawing, it is more obvious that purpose of the present invention and effect will become.

The present invention obtains the method for the average risk of collision of marine ships system, comprises the steps:

Step 1: the AIS data of obtaining a period of time.

Obtain the standard A IS data of the maritime traffic of a period of time from boats and ships VTS system.Extract the data of following field: the mmsi(Hull Number), the shipname(name of vessel), the sog(speed on the ground), the cog(course over ground), the heading(course), the lon(longitude), the lat(latitude) and f_update_time(update time).

Step 2: the aeronautical data of a certain each boats and ships of sampling instant of marine ships AIS extracting data that obtain from step 1.

Extract in the raw data that the aeronautical data of a certain each boats and ships of sampling instant is obtained from step 1, the form of preservation is identical with step 1.

Step 3: the data that step 2 obtains are carried out hierarchical clustering and divided classification.

Boats and ships data in extraction step 2, each data is two-dimensional spaces, is obtained by the conversion through actual range of the longitude of boats and ships and latitude, and its conversion is that intersection point take zero degree warp and parallel is as imaginary coordinate axis initial point, being eastwards positive x direction, is northwards positive y direction.Market demand bee-line (Euclidean distance) method cluster to a sampling instant of N the boats and ships later that convert obtains size and is the class of N, and N is ships quantity.This class is a complete hierarchical tree, its reflection be relation between the boats and ships geographic distance, gather into from the near to the remote a class by distance between boats and ships.Then we are with a distance threshold d crosscut clustering tree, this value will block tree several connect, the boats and ships node division that belongs to each connection is a class.Therefore whole marine intelligent transportation network is gathered into some classes, is designated as { C ₁, C ₂, C ₃..., C _n, wherein, C _iThe class that clustering obtains, i=1,2 ..., n, n are natural number.Between the boats and ships in each class, geographic distance is no more than d.Its physical significance is: belonging to the ultimate range between the boats and ships in class is d, and in other words, suitable selected threshold d can be divided into a class at a distance of nearer boats and ships with the geographic position.From the angle of ship collision risk identification, bump between the nearer boats and ships probability of event of distance is obviously higher, so when computing system risk of collision next, do not need to consider to belong to the risk of collision between inhomogeneous boats and ships.Fig. 1 and Fig. 2 are the schematic diagram of said method.

Step 4: to the some classes that obtain in step 3, carry out the layering abbreviation.

To the class { C that obtains in step 3 ₁, C ₂, C ₃..., C _n, further simplify.At first stipulate S _iRepresent the i straton system of marine intelligent transportation network, S _i,jBe j system in i straton system.Layering abbreviation to class is specially:

If 4.1 C _iIn only have a node, obviously the boats and ships in such do not consist of collision system, need not to consider.

If 4.2 C _iIn only have two nodes, if satisfy 0≤TCPA≤t ₂(TCPA is the shortest meeting chance time, t ₂The attention time), as second layer subsystem S _{2, j;}Otherwise, need not to consider;

If 4.3 C _iMiddle nodes travels through C more than two _iIn node in twos pair, screening stays satisfies 0≤TCPA≤t ₂Node pair; If without qualified node pair, need not so to consider such; Otherwise, these nodes to integral body as second layer subsystem S _{2, j}If the node logarithm surpasses 1, so also need carry out following simplification:

4.3.1 note consists of certain second layer subsystem S _{2, j}In respective nodes to being the 4th straton S of system ₄={ S _4,1, S _4,2S _{4, k}, i=1;

If 4.3.2

J=1, X _i=S _{4, j}(X _iIntermediate variable); Otherwise, carry out 4.3.8;

If 4.3.3 j＜k, j=j+1;

If 4.3.4 X _i=S _{4, j}∪ X _i

4.3.5, repeating step 4.3.3 and 4.3.4;

4.3.6、S ₄=S ₄-X _i,i=i+1；

4.3.7, repeat 4.3.2～4.3.6;

4.3.8, X _iIn all nodes to consisting of S _{3, i}

4.3.9, return to this second layer S of system _{2, j}The 3rd corresponding straton S of system _3,1, S _3,2

4.4, repeating step 4.1-4.3, travel through all classes, the level that finally obtains whole marine intelligent transportation network is divided.The ground floor system is marine intelligent transportation network, and it comprises several second layer subsystems, and each second layer subsystem comprises some the 3rd straton systems, and each the 3rd straton system is comprised of some the 4th straton systems again.Whole hierarchical relationship as shown in Figure 3.Attention: for the second layer subsystem that only has two ship collision avoidance systems, the 3rd layer of this system, the 4th straton system are the same with second layer subsystem.Finally, whole marine intelligent transportation network is divided into the system of four levels, and some do not need to consider that the boats and ships of risk of collision are disallowable, has reduced computational complexity.

Step 5: to the every straton system that obtains in step 4, calculate its system's risk of collision.

5.1 calculate the risk of the 4th straton system

The 4th straton system is actually two ship collision avoidance systems.Adopt Zhou Jianghua, Wu Chunjie: the structure of Collision Risk Factor Model, University Of Ningbo's journal (science and engineering version), 2004,17(1), the described method of 61-65. is calculated in the 4th straton system two ships Risk-Degree of Collision f separately _{1 → 2}(1 with respect to 2 Risk-Degree of Collision) and f _{2 → 1}(2 for 1 Risk-Degree of Collision).Note f ₁₂It is system's risk of collision of boats and ships 1 and 2 collision avoidance systems that consist of.Common f _{1 → 2}≠ f _{2 → 1}, f _{1 → 2},

If use f _{1 → 2}And f _{2 → 1}In any one weigh the entire system risk of collision of two ships, all have certain one-sidedness, must cause ignoring or weaken another Risk-Degree of Collision to the contribution of entire system risk of collision.But due to f _{1 → 2}, f _{2 → 1}And f ₁₂Be from the sign of different angles to same problem, certainly exist some contacts between the three.Here adopt f _{1 → 2}And f _{2 → 1}The mode of weighting obtains f ₁₂, namely

f ₁₂=αf _1→2+βf _2→1

Wherein, α and β are respectively the weights of two risk factors, and they satisfy alpha+beta=1.According to the ultimate principle that linear weighted function merges, weight can be determined the contribution of system's risk of collision according to each Risk-Degree of Collision in this system.The contribution boats and ships less than risk factor that are appreciated that the boats and ships that risk factor is larger are contributed large.But, for two ship collision avoidance systems, f _{1 → 2}And f _{2 → 1}Become when being, become when its weight (α, β) should be also so.Therefore, get α=f _{1 → 2}(f _{1 → 2}+ f _{2 → 1}) and β=f _{2 → 1}(f _{1 → 2}+ f _{2 → 1}),

$f_{12}=\frac{{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA00002744498900011.png"\; state="\{\{state\}\}">f</figure-callout>}}_{1\&RightArrow;2}}{{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA00002744498900011.png"\; state="\{\{state\}\}">f</figure-callout>}}_{1\&RightArrow;2}+{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002744498900011.png,HDA00002744498900012.png"\; state="\{\{state\}\}">f</figure-callout>}}_{2\&RightArrow;1}}{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA00002744498900011.png"\; state="\{\{state\}\}">f</figure-callout>}}_{1\&RightArrow;2}+\frac{{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002744498900011.png,HDA00002744498900012.png"\; state="\{\{state\}\}">f</figure-callout>}}_{2\&RightArrow;1}}{{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA00002744498900011.png"\; state="\{\{state\}\}">f</figure-callout>}}_{1\&RightArrow;2}+{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002744498900011.png,HDA00002744498900012.png"\; state="\{\{state\}\}">f</figure-callout>}}_{2\&RightArrow;1}}{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002744498900011.png,HDA00002744498900012.png"\; state="\{\{state\}\}">f</figure-callout>}}_{2\&RightArrow;1}$

Calculate the 4th straton system risk of collision with this, the 4th straton system risk that obtains is designated as f successively _{4, i}, i=1,2 ..., m ₄, wherein, m ₄It is the number of the 4th straton system.

Above-mentioned weighting scheme is simple, intuitive both, can reflect preferably the impact that two risk factors are portrayed the entire system risk of collision again.Verified, the two boat system risk of collision values that above-mentioned computation model obtains are between [0,1], namely

Its probability as system's collision possibility can be understood so, this also meets the original intention of carrying out the assessment of Vessels Traffic System risk of collision.

5.2 calculate the risk of the 3rd straton system

To the 4th straton system risk that obtains in 5.1, calculate the 3rd straton system risk that belongs to corresponding second layer subsystem.Computing formula is as follows:

J=1,2 ..., m ₃, wherein, f _{3, j}The risk of j three straton systems, m ₃The number of the 3rd straton system, N _{4, j}It is the number that belongs to the 4th straton system of j three straton systems.The 3rd straton system risk of collision that calculates with this average weighted mode can characterize this average risk of collision of straton system from average meaning preferably.

5.3 calculate the risk of second layer subsystem

To the 3rd straton system risk that obtains in 5.2, calculate the risk that belongs to corresponding second layer subsystem.Computing formula is as follows:

J=1,2 ..., m ₂, f wherein _{2, j}The risk of j two straton systems, m ₂The number of second layer subsystem, N _{3, j}It is the number that belongs to the 3rd straton system of j two straton systems.The second layer subsystem risk of collision that calculates with this average weighted mode can characterize this average risk of collision of straton system from average meaning preferably.

5.4 calculating ground floor system, i.e. system's risk of collision of marine intelligent transportation network

To the second layer subsystem risk that obtains in 5.3, calculate the risk f of ground floor system ₁Computing formula is as follows:

Wherein, m ₂It is the number of second layer subsystem.The ground floor system risk of collision that calculates with this average weighted mode can characterize the average risk of collision of whole system from average meaning preferably.

Layering through above-mentioned three sub-steps is calculated, can obtain the average risk of collision of whole marine ships system, and this algorithm can also demonstrate system's risk of collision of each subsystem effectively, reflects the situation of system's risk of collision and the risk situation of subregion from macroscopic view integral body and two aspects of subdivision.

Step 6: according to system's risk of collision of the marine intelligent transportation network of result judgement.

Choose suitable risk threshold value according to experience.Choose f=0.4 in the present invention as risk threshold value.

f ₁During 〉=f, think that whole marine intelligent transportation network on-demand system risk of collision is larger.

f ₁During＜f, think that the on-demand system risk of collision of whole marine intelligent transportation network is less.

Because each straton system of systems risk of collision all can obtain in above-mentioned computation process, maritime affairs managerial personnel can monitor by the larger subsystem of selecting system risk of collision.

System's risk of collision acquisition methods of a kind of marine intelligent transportation network of the present invention is based on information fusion and hierarchical cluster, and whole marine intelligent transportation topology of networks is simplified, and avoids calculating the complicacy of the traversal of two foul risks; At first build system's risk of collision of two ship collision avoidance systems, then based on the result of this and system's abbreviation, with bottom-up Weighted Fusion method, calculated the subsystem risk of collision of every one deck and system of systems risk of collision greatly.Final result can be the macro-management maritime traffic of maritime affairs administrative authoritys, and the evaluating system risk of collision of identification is as quantitative foundation.

Claims (1)

1. a method of obtaining the average risk of collision of marine ships system, is characterized in that, the method comprises the steps:

(1) obtain the AIS data of a period of time: the standard A IS data of obtaining the maritime traffic of a period of time from boats and ships VTS system; Extract the data of following field: mmsi, shipname, sog, cog, heading, lon, lat and f_update_time.

The aeronautical data of a certain each boats and ships of sampling instant of marine ships AIS extracting data that (2) obtain from step 1.

(3) data that step 2 obtained are carried out hierarchical clustering and are divided classification: boats and ships data in extraction step 2, these data are two-dimensional spaces, obtained by the longitude of boats and ships and the conversion of latitude process actual range, its conversion is that intersection point take zero degree warp and parallel is as imaginary coordinate axis initial point, being eastwards positive x direction, is northwards positive y direction.Market demand bee-line (Euclidean distance) method cluster to a sampling instant of N the boats and ships later that convert obtains size and is the class of N, and N is ships quantity.This class is a complete hierarchical tree, its reflection be relation between the boats and ships geographic distance, gather into from the near to the remote a class by distance between boats and ships.Then use a distance threshold d crosscut clustering tree, this value will be blocked several connections of tree, and the boats and ships node division that belongs to each connection is a class.Therefore whole marine intelligent transportation network is gathered into some classes, is designated as { C ₁, C ₂, C ₃..., C _n, wherein, C _iThe class that clustering obtains, i=1,2 ..., n, n are natural number.Between the boats and ships in each class, geographic distance is no more than d.

(4) the some classes to obtaining in step 3, carry out the layering abbreviation: to the class { C that obtains in step 3 ₁, C ₂, C ₃..., C _n, further simplify.At first stipulate S _iRepresent the i straton system of marine intelligent transportation network, S _i,jBe j system in i straton system.Layering abbreviation to class is specially:

(4.1) if C _iIn only have a node, obviously the boats and ships in such do not consist of collision system, need not to consider.

(4.2) if C _iIn only have two nodes, if satisfy 0≤TCPA≤t ₂(TCPA is the shortest meeting chance time, t ₂The attention time), as second layer subsystem S _{2, j}Otherwise, need not to consider;

(4.3) if C _iMiddle nodes travels through C more than two _iIn node in twos pair, screening stays satisfies 0≤TCPA≤t ₂Node pair; If without qualified node pair, need not so to consider such; Otherwise, these nodes to integral body as second layer subsystem S _{2, j}If the node logarithm surpasses 1, so also need carry out following simplification:

(4.3.1) note consists of certain second layer subsystem S _{2, j}In respective nodes to being the 4th straton S of system ₄={ S _4,1, S _4,2S _{4, k}, i=1;

If (4.3.2)

J=1, X _i=S _{4, j}(X _iIntermediate variable); Otherwise, carry out 4.3.8;

If (4.3.3) j＜k, j=j+1;

If (4.3.4)

X _i=S _{4, j}∪ X _i

(4.3.5) repeating step 4.3.3 and 4.3.4;

（4.3.6）S ₄=S ₄-X _i,i=i+1；

(4.3.7) repeat 4.3.2～4.3.6;

(4.3.8) X _iIn all nodes to consisting of S _{3, i}

(4.3.9) return to this second layer S of system _{2, j}The 3rd corresponding straton S of system _3,1, S _3,2

(4.4) repeating step 4.1-4.3 travels through all classes, and the level that finally obtains whole marine intelligent transportation network is divided.The ground floor system is marine intelligent transportation network, and it comprises several second layer subsystems, and each second layer subsystem comprises some the 3rd straton systems, and each the 3rd straton system is comprised of some the 4th straton systems again.

(5) the every straton system to obtaining in step 4, calculate its system's risk of collision, specifically comprise the following steps: (5.1) calculate the risk of the 4th straton system: the 4th straton system is actually two ship collision avoidance systems, calculates in the 4th straton system two ships Risk-Degree of Collision f separately _{1 → 2}(the 1st ship is with respect to the Risk-Degree of Collision of the 2nd ship) and f _{2 → 1}(the 2nd ship is for the Risk-Degree of Collision of the 1st ship).Note f ₁₂It is system's risk of collision of the collision avoidance system of the 1st ship and the 2nd ship formation; f ₁₂=α f _{1 → 2}+ β f _{2 → 1}Wherein, α and β are respectively the weights of two risk factors, and they satisfy alpha+beta=1.α=f _{1 → 2}(f _{1 → 2}+ f _{2 → 1}), β=f _{2 → 1}(f _{1 → 2}+ f _{2 → 1}):

$f_{12}=\frac{f_{1\&RightArrow;2}}{f_{1\&RightArrow;2}+f_{2\&RightArrow;1}}{f}_{1\&RightArrow;2}+\frac{f_{2\&RightArrow;1}}{f_{1\&RightArrow;2}+f_{2\&RightArrow;1}}{f}_{2\&RightArrow;1};$

Calculate the 4th straton system risk of collision with this, the 4th straton system risk that obtains is designated as f successively _{4, i}, i=1,2 ..., m ₄, wherein, m ₄It is the number of the 4th straton system.

(5.2) calculate the risk of the 3rd straton system: to the 4th straton system risk that obtains in 5.1, calculate the 3rd straton system risk that belongs to corresponding second layer subsystem.Computing formula is as follows:

J=1,2 ..., m ₃, f wherein _{3, j}The risk of j three straton systems, m ₃The number of the 3rd straton system, N _{4, j}It is the number that belongs to the 4th straton system of j three straton systems.

(5.3) calculate the risk of second layer subsystem: to the 3rd straton system risk that obtains in 5.2, calculate the risk of corresponding second layer subsystem.Computing formula is as follows:

J=1,2 ..., m ₂, f wherein _{2, j}The risk of j two straton systems, m ₂The number of second layer subsystem, N _{3, j}It is the number that belongs to the 3rd straton system of j two straton systems.

(5.4) calculate the ground floor system, i.e. system's risk of collision of marine intelligent transportation network: to the second layer subsystem risk that obtains in 5.3, calculate the risk f of ground floor system ₁Computing formula is as follows:

M wherein ₂It is the number of second layer subsystem.

(6) judge system's risk of collision of marine intelligent transportation network: f according to result ₁During 〉=f, think that whole marine intelligent transportation network on-demand system risk of collision is larger, f ₁During＜f, think that the on-demand system risk of collision of whole marine intelligent transportation network is less; Wherein, f is risk threshold value.

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