CN115018304A

CN115018304A - Method and device for calculating ship-computer collision risk and storage medium

Info

Publication number: CN115018304A
Application number: CN202210605509.3A
Authority: CN
Inventors: 余庆; 陈国权; 杨神化; 林婷婷; 纪惠婷
Original assignee: Jimei University
Current assignee: Jimei University
Priority date: 2022-05-31
Filing date: 2022-05-31
Publication date: 2022-09-06

Abstract

The invention relates to the technical field of ship navigation. The invention discloses a method for calculating the collision risk of a ship and a computer, which comprises the following steps: determining a safety region of a wind power plant; determining a motion reachable set of the ship according to the speed, the limit rudder angle and the reachable set prediction time of the ship, wherein the motion reachable set comprises all positions of the ship reached within the prediction time; calculating an overlapping area of the safe area and the motion reachable set, and determining that the ship has no collision conflict with the wind power plant at the current moment when the overlapping area is zero; and when the overlapping area is not zero, determining that the collision conflict of the ship and the wind power plant exists at the current moment, wherein the degree of the collision conflict is represented by the area ratio of the overlapping area and the motion reachable set. The method and the device for calculating the ship-computer collision risk can consider the influence of multiple factors on the ship-computer collision risk under the wind power water area environment, have better applicability to the wind power plant, and show better risk calculation real-time performance and sensitivity in the practical process.

Description

Method and device for calculating ship-computer collision risk and storage medium

Technical Field

The invention relates to the technical field of ship navigation, in particular to a method and a device for calculating ship-computer collision risk and a storage medium.

Background

A collision accident of a ship generally refers to an accident in which the ship is damaged by contact in a water area. According to the definitions of the convention of collision avoidance at sea, the convention of collision damage and compensation international convention of ships and the like, the collision accidents of ships can be divided into two aspects of broad sense and narrow sense: a narrow defined collision of vessels usually refers to an accident in which two or more vessels actually contact each other for various reasons, thereby causing damage. And the broad ship collision includes the collision accident between ships, and also includes the collision accident between the ship and other non-navigable ships, machines, derricks, platforms and equipment. The definition includes the actual physical contact, and also includes the collision accidents of the ships caused by wave damage and indirect collision. According to the statistics of marine accident cases in recent years, it can be found that the ship collision accidents account for more than 60% of all water accidents, which can cause serious consequences such as ship structure and cargo damage, casualties, oil contamination leakage, ship sinking and the like, and are key risks affecting the ship navigation safety.

Newly-built offshore wind power plants may invade nearby navigable water areas, change ship navigation behaviors and water area traffic flow distribution, increase collision risks among ships and cause collision risks between ships and fans. In offshore wind power water areas, ship/machine collision accidents seriously threaten the safety of ships and fan equipment, and can cause serious consequences such as ship overturning, fan collapse, personal injury and death and the like. According to researches of English coast guard (Maritime and coast guard Agency), the offshore wind farm can cause various influences including vision, radar observation, radio communication interference and the like on nearby sailing ships, and the sailing risk of the ships is increased. The real-time evaluation of the collision risk of the ship-plane in the wind power water area can be carried out, the sailing risk condition of the ship in the wind power water area can be objectively and accurately reflected, the early warning of the ship risk in the water area can be effectively supported, the accident risk in the water area is reduced, and the sailing safety level of the ship in the wind power water area is further improved.

The reasonable evaluation of the collision risk of the single ship and the fan in the wind power water area can help to reflect the navigation risk condition of the wind power water area from the microcosmic single ship layer, and further improve the navigation safety management level of the ship in the wind power water area.

Disclosure of Invention

In order to overcome the technical problems, the invention provides a method for calculating the ship-computer collision risk, which is used for calculating the ship-computer collision risk of a ship and a fan in the water of an offshore wind farm, and the technical scheme of the method is as follows:

s1, determining a safety region of the wind power plant;

s2, determining a motion reachable set of the ship according to the speed, the limit rudder angle and reachable set prediction time t of the ship, wherein the motion reachable set comprises all positions of the ship reached within the prediction time t, and t is a positive number;

s3, calculating an overlapping area of the safe area and the motion reachable set, and determining that the ship has no collision conflict with the wind power plant at the current moment when the overlapping area is zero; when the overlap region is not zero, determining that the ship has collision conflict with the wind power plant at the current moment, wherein the degree of the collision conflict is represented by the area ratio of the overlap region to the motion reachable set.

Further, the step S1 includes:

under the condition of known route distribution, according to a preset receiving threshold value of the ship-machine collision risk of the route, calculating a minimum safe distance corresponding to the risk receiving threshold value through a Monte Carlo simulation theory to obtain a safe area of the wind power plant, wherein a calculation formula of the ship-machine collision risk of the route is as follows:

P＝P ₁ +P ₂ ；

wherein P is the annual average probability of the risk of a collision of the ship with the aircraft on the route, P ₁ Annual probability of dynamic collision of ship, P ₂ Annual probability of ship drift collision, N _i Is the total number of ships in the route i, P _ib Probability of an out-of-control event, P, of a vessel in the way i _F Is the failure probability of the ship, P _cw Is the wind and flow deflection probability, P _w Is the wind-induced partial probability, P _c For flow deflection probability, ρ _a Is the density of air, V _a Is the wind speed, A _L The projected area of the wind area on the ship waterline in the ship length direction, L _oA Is the length of the ship, C _a Is the wind pressure resultant coefficient, rho _c Is the density of ocean currents, V _c Is the velocity of the ocean current, A _sl Is the underwater side projection area of the ship, C _c Is the ship flow pressure coefficient, N is the number of sub-distribution functions contained in the Gaussian mixture distribution function, w _j For weight, σ, of sub-distribution function _j For the jth sub-distribution function f (x) _j ) Variance of inner vessel distribution, μ _j Is the jth subDistribution function f (x) _j ) Mean, x, of the distribution of the internal vessels _j For the jth distribution function f (x) _j ) Theta is the course of the ship, N is more than or equal to 3, j belongs to N, and i is a positive integer.

Further, the method also comprises the following steps: and when the distance is smaller than a preset monitoring distance and larger than the minimum safety distance, calculating the collision risk of the ship and the aircraft in real time according to steps S1-S3.

Further, the motion reachable set is calculated by combining a ManeuveringModel Group (MMG) model, where the MMG model uses the following formula:

wherein G represents the position of the gravity center point of the ship, m represents the mass of the ship,

and

acceleration of the ship along an x axis and an y axis respectively,

for the steering angular acceleration of the vessel, u _G And v _G Speed of the vessel along the x-axis and y-axis, r, respectively _G For the steering angular velocity of the vessel, I _Z Is moment of inertia, X _G 、Y _G Transverse and longitudinal forces, N, respectively, acting on the centre of gravity of the vessel _G The primary moment acting on the center of gravity point for the vessel.

Further, the degree of collision conflict is calculated using the following formula:

wherein P is the degree of collision conflict, x is the ship position, f (x) _overlapped For overlapping areas of the ship's reachable set with the safety area of the wind farm, M ^t (r) is an achievable set function of the ship over a period of time t, r _{port side} And r _{starboard side} The maximum rudder angle of the ship towards the left and right sides is respectively.

Further, when the overlapping region is irregular, the area ratio is calculated using Otsu gray scale processing algorithm, and the area ratio is represented by the inter-class variance ICV, and the formula is as follows:

ICV＝P _A ^ε ×(g _A -g) ² +P _B ^ε ×(g _B -g) ² ；

a, B respectively represents the region with gray value T less than the preset gray threshold T and the region with gray value T greater than the preset gray threshold T in the gray value image, P _A And P _B The number of pixels included in the region A, B, g, is a ratio of the total number of pixels of the entire image _A And g _B The gray value mean of the region A, B, g is the mean of all gray values in the whole image, epsilon is the weight of the regions a and B, and epsilon is 0.8.

Further, the method also comprises the following steps:

s4, distributing the weight of risk factors of the water area of the wind power plant based on an expert evaluation system and a mutual information method in an information entropy theory, and calculating the collision risk of the ship-plane by using an evidence reasoning method in combination with the weight of the risk factors and the collision conflict degree, wherein the risk factors comprise observation negligence, high wind waves, poor visibility, navigation aid facility arrangement conditions and small ship interference;

the formula for calculating the weight of the risk factor is as follows:

w is the weight of the risk factor, X and X are the sample information and the total information quantity of the risk factor respectively, and p (X) is a probability function of the risk factor;

the calculation formula of the evidence reasoning method is as follows:

wherein L is the number of the risk factors,

expert evaluation value of the kth risk factor, j ∈ (Yes, No), w _k Is the weight of the kth risk factor,

in order to be the basis of the probability weights,

in order to not determine the probability weight,

for the result of fusing the impact of the kth risk factor and the (k + 1) th risk factor on the collision risk of the ship-plane, P _j K is a positive integer for the normalized state distribution of the risk of ship-to-aircraft collision.

The invention also provides a device for calculating the collision risk of the ship computer, wherein the device for calculating the collision risk of the ship computer stores computer instructions; the computer instructions perform the method of calculating a risk of a ship-to-computer collision as described in any one of the above at a device for calculating a risk of a ship-to-computer collision.

The invention also proposes a computer-readable storage medium storing computer instructions for causing the computer to carry out a method of calculating a risk of collision for a ship with a computer as defined in any one of the preceding claims.

The technical scheme provided by the invention has the beneficial effects that:

according to the method and the device for calculating the ship-computer collision risk, influence on the ship-computer collision risk caused by multiple factors in the wind power water area environment can be considered, the applicability to the wind power plant is better, and the real-time performance and the sensitivity of risk calculation are better expressed in the practical process.

Drawings

FIG. 1 is a flow chart of a method of calculating a risk of a collision of a ship with a computer according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a typical ship-to-aircraft collision geometry scenario of a wind power water area according to an embodiment of the invention;

FIG. 3 is a geometric representation of a wind power water area ship-to-aircraft collision according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a reachable set of motions of a vessel according to an embodiment of the invention;

FIG. 5 is a schematic diagram of a vessel conflict calculation according to an embodiment of the present invention;

FIG. 6 is a pseudo code of a model for evaluating collision and collision degrees of ships and airplanes according to an embodiment of the present invention;

FIG. 7 is a graph of a calculation result of a safe boundary distance between an airway and a wind farm according to an embodiment of the present invention;

FIG. 8 is a schematic illustration of the range of motion achievable by the vessel at different times in accordance with an embodiment of the present invention;

FIG. 9 is a diagram illustrating a simulation result of ship motion according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of an exemplary embodiment of a ship's reachable set of parameters;

FIG. 11 is a graphical illustration of a risk of collision for a ship engine according to an embodiment of the present invention;

FIG. 12 illustrates a variation in the risk of a collision of the ship with the aircraft at different times in accordance with an embodiment of the present invention;

FIG. 13 is a line graph of comparative results of a model according to an embodiment of the present invention;

fig. 14 is a schematic structural diagram of an apparatus for calculating a collision risk of a ship according to an embodiment of the present invention.

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.

The first embodiment is as follows:

fig. 1 is a flowchart of a method for calculating a collision risk of a ship and a computer according to an embodiment of the present invention, which illustrates specific implementation steps of the method, and includes:

s1, determining a safety area of the wind power plant;

s2, determining a motion reachable set of the ship according to the speed, the limit rudder angle and reachable set prediction time t of the ship, wherein the motion reachable set comprises all positions reached by the ship within the prediction time t, and t is a positive number;

Specifically, the step S1 includes:

under the condition of known route distribution, according to a preset receiving threshold value of the ship-aircraft collision risk of the route, calculating a minimum safe distance corresponding to the risk receiving threshold value through a Monte Carlo simulation theory, and obtaining a safe area of the wind power plant.

Specifically, still include: and when the distance is smaller than a preset monitoring distance and larger than the minimum safety distance, calculating the collision risk of the ship and the aircraft in real time according to steps S1-S3.

Specifically, the motion reachable set is calculated by combining a Manual Model Group (MMG) Model, where a formula used by the MMG Model is as follows:

and

acceleration of the ship along an x axis and an y axis respectively,

for the steering angular acceleration of the vessel, u _G And v _G Speed of the vessel along the x-axis, y-axis, r _G For the steering angular velocity of the vessel, I _Z Is moment of inertia, X _G 、Y _G Transverse and longitudinal forces, N, respectively, acting on the centre of gravity of the vessel _G The primary moment acting on the center of gravity point for the vessel.

Specifically, the degree of collision conflict is calculated using the following formula:

wherein P is the degree of collision conflict and x is the shipPosition of the vessel, f (x) _overlapped For overlapping areas of the ship's reachable set with the safety area of the wind farm, M ^t (r) is an achievable set function of the ship over a period of time t, r _{port side} And r _{starboard side} The maximum rudder angle of the ship towards the left and right sides is respectively.

Specifically, when the overlapping region is an irregular shape, the area ratio is calculated using an Otsu gray scale processing algorithm, and the area ratio is represented by an inter-class variance ICV, and the formula is as follows:

ICV＝P _A ^ε ×(g _A -g) ² +P _B ^ε ×(g _B -g) ² ；

a, B respectively represents the region with gray value T less than the preset gray threshold T and the region with gray value T greater than the preset gray threshold T in the gray value image, P _A And P _B The number of pixels included in the region A, B, g, is a ratio of the total number of pixels of the entire image _A And g _B The gray value mean of the region A, B, g is the mean of all the gray values in the whole image, epsilon is the weight of the regions a and B, and epsilon is 0.8.

Specifically, the method further comprises the following steps:

and S4, distributing the weight of the risk factors of the water area of the wind power plant based on an expert evaluation system and a mutual information method in an information entropy theory, and calculating the collision risk of the ship and the aircraft by using an evidence reasoning method by combining the weight of the risk factors and the collision conflict degree, wherein the risk factors comprise observation negligence, high wind waves, poor visibility, navigation aid facility arrangement condition and small ship interference.

The second embodiment:

aiming at the problems of limited sailing behavior of ships in the offshore wind power water area, obvious sailing risk multi-factor coupling influence, difficult dynamic real-time quantification of ship/machine collision risk and the like, the invention comprehensively considers the difference between the ship/machine safety distance and the single ship motion performance of the wind power water area, uses Monte Carlo simulation to calculate parameters in the safety field of the wind power plant, and provides a ship/machine collision conflict quantification method based on ship reachable sets; on the basis, corresponding risk correction factors are selected according to the risk element sequencing result, and ship/machine collision risk evaluation under the influence of multiple factors is carried out by adopting methods such as mutual information and evidence reasoning, so that dynamic evaluation modeling of ship/machine collision risk in the wind power water area is realized, and case verification is carried out.

Fig. 2 is a schematic diagram of a typical ship-to-aircraft collision geometric scene of a wind power water area according to an embodiment of the present invention, which is different from ship-to-ship collision risk calculation, and when a ship approaches an offshore wind farm water area without considering influence of wind current and other external factors, the following three typical scenes may exist:

FIG. 2(a) shows a ship in the bow direction θ ₁ Approaching a wind power water area, and at the moment, the relative position of the wind power field and the ship is sigma ^- (far point) to. sigma ⁺ (near point), and θ ₁ ≤σ ^- ≤σ ⁺ The ship will pass from the end of the wind farm. In fig. 2(b), the ship has a bow direction θ ₂ Driving into a wind power water area; relative ship orientation of wind power plant is sigma ^- ≤θ ₂ ≤σ ⁺ I.e. the fore-aft direction theta of the vessel ₂ Between σ ^- And σ ⁺ If the ship continues to keep the course of the ship, the ship directly drives into a wind power plant area, and the risk of ship/machine collision exists; in fig. 2(c), the ship has a bow direction θ ₃ Driving to wind power water area, at the moment, sigma ^- ≤σ ⁺ ≤θ ₃ And the ship and the fan have no collision conflict, and the ship passes through the water area below the wind power plant.

The invention mainly analyzes the collision risk between the ship and the fan equipment in fig. 2(b), and as shown in fig. 3, the invention is a geometrical diagram of the collision between the ship and the fan in the wind power water area according to the embodiment of the invention:

in fig. 3 the vessel approaches the wind farm at sea at a speed V and heading θ, which is located within the total length of the airway side. The position of the ship is taken as the origin of a coordinate system, and the X axis and the Y axis in the coordinate system are respectively in the east and north directions. At the moment, the closest distance of the ship from the water area of the wind power plant is D, and the closest distance can be decomposed into a corresponding horizontal distance D _h And a vertical distance D _v . Therefore, the collision probability of the ship and the wind power plant is respectively obtained according to the ship speed V, the course theta, the length l of the wind power plant close to the airway boundary and the transverse interval distance D of the ship wind power plant _h And longitudinal direction of ship wind power plantSpaced apart by a distance D _v It is related.

After the geometric parameters are obtained, the geometric collision equation of the ship can be generally used for calculating the geometric parameters such as the relative spacing position between ships and the aircraft, the distance, the ship course, the ship speed and the like, but the size of the collision risk parameters such as the minimum meeting distance, the minimum meeting time and the like cannot be obtained, and the influence of the ship collision probability caused by different types, the tonnage ship mobility difference and the water area environment difference cannot be considered only on the basis of a ship collision set model, so that the method is not suitable for calculating the collision risk of the ship and the aircraft in the wind power water area. Therefore, the invention provides a new ship/machine collision risk model on the basis of using the collision geometric parameters, and realizes the real-time quantification of the ship/machine collision risk in the wind power water area.

In order to comprehensively consider the influence of different ship and environment changes on the ship/machine collision risk, the method is based on the real airway traffic flow distribution data of the wind power water area, a Pedersen traffic flow conflict Model (Pedersen Model) is improved by using a traffic flow Gaussian mixture distribution method, and the wind power plant safety boundary distance is calculated by means of Monte Carlo Simulation (Monte Carlo Simulation); the method provided by the invention improves the three-degree-of-freedom motion model of the ship on the basis of further considering the influence of wind flow on the ship, obtains the ship reachable boundary of the target ship at any moment through a simulation experiment method and constructs a reachable set. On the basis, the invention provides a ship-aircraft collision conflict evaluation method based on ship motion space conflict, and the real-time calculation of ship collision conflict indexes is realized.

When the ship passes through a water area of a wind power plant, a proper safe distance can be selected according to various factors such as the type of the ship, the hydrological environment and the like, so that the navigation risk of the ship is reduced. According to the definition of vessel collisions within a traffic flow in the Pedersen model (Pedersen model), the risk of a vessel colliding with a wind farm within a particular traffic flow may be represented by the following equations 1-3:

P＝P ₁ +P ₂ (1)

assuming that the annual average probability of the collision between the ship and the fan in a specific route is P, the annual probability of the dynamic collision of the ship is P ₁ Annual probability of drift collision with ship ₂ And (4) forming. N is a radical of _i The total number of ships in a specific route i; p _ib Probability of an out-of-control event occurring for a particular vessel; the probability of the ship maneuvering collision is related to the course distribution density function f (theta) and the space-time position distribution f (x) of the ship. P _F 、P _cw Respectively the ship failure probability and the wind and flow deviation probability. Wherein i is a positive integer.

Wind and flow deflection probability P _cw Deviation probability P caused by wind _w Deviation from flow probability P _c And (5) obtaining the results together. The drift generated by the wind action of the ship is mainly related to parameters such as wind area, wind side angle and the like on the water surface of the ship, and can be represented by the following formula:

in equation 4 ρ _a Is the density of air, V _a Is the wind speed, A _L For the wind area on the ship waterline projected in the ship length direction, L _oA Is the captain of the ship, C _a For the wind pressure resultant coefficient, regression formulas obtained by developing statistics for general cargo ships, passenger (rolling) ships and oil tankers can be respectively set as:

the convection current ship-turning force can assume that the current acting force borne by the ship in the time of passing through the wind power water area is constant, and then the deflection probability of the ship after being influenced by the current can be calculated by the following formula:

a in equation 6 _sl Respectively, the underwater orthographic projection and the side projection area, V, of the ship _c As the velocity of the sea current, ρ _c And C _c The sea current density and the ship current pressure coefficient are respectively, and are generally obtained through statistics.

For the parameter f (x), the conventional Pittson model adopts a normal distribution model to represent the space-time position distribution of the ship. However, in most cases, the vessels in the airways do not completely follow the normal function distribution characteristics, and the normal distribution function is used for traffic flow distribution modeling, so that errors exist in the calculation results. The invention improves the calculation of the ship distribution probability density function f (theta) by using a Gaussian mixture distribution model. The distribution of the ships in any route can be represented by the following formula:

assuming that the Gaussian mixture distribution function includes N sub-distribution functions (N ≧ 3) where μ _j And σ _j For the jth distribution function f (x) _j ) Mean and variance of the inner vessel distribution (j ∈ N), w _j Weights are assigned to the sub-distribution functions. After the characteristic parameters of all the distribution functions are obtained, the ship passing probability in any interval in the air route can be obtained by calculation through the constructed traffic flow Gaussian mixture distribution model. The interval occupied by the wind power plant on the section of the airway is assumed to be (x) ₁ ,x ₂ ) Substituting the above parameters into equation 7, one can obtain:

based on the calculation steps, under the condition of known route distribution, only a specific route risk acceptance threshold value needs to be set, namely the minimum safe distance of the corresponding route can be reversely deduced through the Monte Carlo simulation theory, and the safe boundary distance corresponding to the wind power threshold value is calculated.

Under the condition that specific single-ship parameters are known, the motion state of the ship in a period of time can be predicted by using a constructed ship motion state model, all position forming regions which can be reached by the ship in a specified time are motion reachable sets of the ship in the time t, and the ship cannot exceed reachable set boundaries in any state. Fig. 4 is a schematic diagram of a reachable set of ship motions according to an embodiment of the present invention, for example, a reachable set of motions of a certain ship at time t can be represented by fig. 4 (a). It can be found that under the premise of keeping the constant-speed operation of the ship, the ship position of the ship after time t falls on the inner arc boundary of the figure when the ship adopts any steering operation; if the ship takes corresponding speed reduction measures besides the steering action in the period of time, the ship position is in the reachable shadow region at the time t.

To simplify the calculation, we abstract this vessel motion reachable set to the graph shown in fig. 4 (b). In the figure, point O is the position of the bow, point C is the farthest distance that can be reached in time t when the ship keeps moving at a constant speed v (| OC | ═ vt), and points a and B are the limit positions that the ship can reach in time t under the condition that the ship adopts a limit rudder angle (generally not exceeding 30 ° left and right), and can be calculated by a ship motion equation. Then the reachable set M of a ship at time t can be expressed as: m- (| OA |, alpha, v, t) respectively forms an included angle alpha with OC and OA, the ship speed v and the reachable set prediction time t.

The ship reachable set calculation is carried out by using the ship maneuvering motion performance model, and common models comprise a linear motion equation and a nonlinear motion equation. Among them, the linear motion model is mainly represented by a Nomoto model (also referred to as KT model). The model has simple calculation steps and can simply predict the ship maneuvering motion. However, the linear model has certain difficulty in describing the motion difference caused by the rotation deceleration of the ship, and a nonlinear mathematical model is generally adopted to model the ship three-degree-of-freedom motion in order to describe the ship motion more accurately. Common non-linear ship motion models include an Abkowitz Model and a Maneuvering Model Group Model (MMG Model), and the MMG Model is used for ship motion modeling in the invention.

The MMG model describes the motion of a ship in three degrees of freedom using the following basic equations, respectively:

in the formula 10, G represents a value of a certain parameter at the center of gravity of the ship, and usually, for simplified calculation, it is assumed that the center point of the ship is set as the position of the center of gravity of the ship. m is the ship mass, V is the ship speed,

and

acceleration of the ship along an x axis and an y axis respectively,

for the steering angular acceleration, X, of the vessel _G 、Y _G Transverse, longitudinal forces acting on the centre of gravity for the vessel, N _G The yawing moment acting on the centre of gravity point for the vessel. The MMG model in the invention mainly considers the influence of the following forces on the ship:

1) the inertial force of the fluid. The force is mainly the force and moment generated by the inertia fluid acting on the hull when the speed and direction of the ship are changed, and can be simplified and processed into additional mass (transverse and longitudinal) and additional inertia moment of the hull. This force is generally calculated by empirical formulas.

2) Fluid viscosity-like forces. Due to the viscous character of water, a ship is subjected to the resistance that the water generates to the ship when sailing in the water. In the invention, the force and the moment are generally decomposed into a linear part and a nonlinear part, and the force and the moment can be calculated by using a fluid mechanics model proposed on the well.

3) Propeller longitudinal force. Mainly the force and moment generated by the propeller acting on water, and is the main power source for ship running. The force can be calculated and obtained according to propeller parameters by referring to a hydrodynamic performance map, and the method only considers that the propeller provides thrust for ship navigation and does not consider the deflection effect of the propeller.

4) And (4) rudder force. The force is the acting force and moment of the water on the rudder blade under a certain rudder angle. The force can cause the transverse movement (horizontal force) and the deceleration (longitudinal force) of the ship besides generating the steering moment of the ship, and the magnitude of the two forces can be calculated by a vector decomposition method according to the steering angle.

After the ship is stressed and calculated at any moment, parameters such as angular speed, speed and the like of the ship at a future time t are analyzed by using an MMG model, the arrival position of the ship after any steering or deceleration behavior in a future specific time can be obtained, a specific ship reachable set can be obtained by using Monte Carlo simulation to generate random parameters of the steering angle and speed and calculating, and a characteristic parameter alpha of the reachable set required by the method is calculated.

According to the set simulation of the distance of the wind power plant safety protection area and the calculation result of the maximum reachable set of the ship, the collision conflict between the ship and the machine is defined as follows: if at any moment, an overlapping area exists between an reachable set of a sailing ship and a safety area of a wind power plant within t time, the ship is considered to have collision conflict with the wind power plant at the moment, and the conflict size is the overlapping area ratio of the reachable set to the safety protection area, and fig. 5 is a schematic diagram of ship conflict calculation according to the embodiment of the invention.

The ratio of the overlapping area to the reachable set of the ship in fig. 5 is the collision and collision degree of the ship, and can be obtained by equation 11:

in equation 11, P is the collision degree of ship/machine collision, f (x) _overlapped For the area where the ship reachable set overlaps with the wind farm safety zone, M ^t (r) is an achievable set function of the vessel over a period of time t, where r _{port side} ，r _{starboard side} The maximum rudder angle of the ship towards the left and right sides can be respectively used. Based on the above thought, fig. 6 shows pseudo codes of a ship-aircraft collision degree evaluation model according to an embodiment of the present invention.

In FIG. 6, except for the defined parameters P, f (x) _overlapped Outside M, D represents the minimum distance between the current ship and the wind farm area, D ₁ For the set wind power water area ship monitoring distance, generally taking 4 seas, D ₂ Representing the safety protection distance of the wind power plant, the safety protection distance can be 0.5 nautical miles, theta is the current course of the ship, and sigma is ^- 、σ ⁺ The method comprises the steps of respectively representing the relative positions of a far point, a near point and a ship of a wind power plant, J representing a safety protection area of the wind power plant, K representing a ship monitoring area, alpha representing an included angle in an reachable set of the ship, V representing the speed of the ship, and t representing the set reachable set prediction time.

It is to be noted that, since the overlapping region is usually an irregular figure, in order to calculate the overlapping area between the reachable set of the ship and the fan protection region, we use an image binarization processing method to perform the overlapping region calculation by means of an Otsu gray scale processing algorithm in MATLAB software, where the algorithm defines the following formula:

ICV＝P _A ^ε ×(g _A -g) ² +P _B ^ε ×(g _B -g) ² (12)

wherein A, B represents the number of gray values T smaller than the threshold value T and the number of gray values T larger than the threshold value T in the gray value image, respectively, and the ratio of the gray values T in the gray value image to the threshold value T is obtained _A And P _B Mean value of gray scale is g _A And g _B The mean g of all gray values in the whole image. To enhance the image-based effect, a weight ∈ may be given to the two divided regions, and is usually equal to 0.8. After the parameters are obtained, the ratio of the accessible set of the ship to the image in the overlapping area can be obtained through the gray difference in the image, and the value of the ICV in the specific image is maximized through binarization processing. When the ICV takes the maximum value, the space where the gray level T of the pixel point is larger than T is the size of the overlapping area in the scene.

When a ship sails in an offshore wind farm water area, besides the potential collision conflict caused by ship motion, the influence of various factors such as surrounding traffic flow environment, navigation facility layout conditions, natural conditions and the like on the ship sailing needs to be considered. According to the method, the potential risk of ship navigation is considered, the expert evaluation opinions are further combined based on the geometric collision conflict quantification result, and an evidence reasoning method is used for constructing a ship/machine collision risk quantification model under the influence of multiple factors, so that the dynamic calculation of the single-ship collision risk in the wind power water area is realized.

According to the research of domestic and foreign documents, the sailing safety of ships in offshore wind power water areas is influenced by various environments such as nature, navigation routes and the like, and on the basis of calculating and obtaining the collision conflict degree of the ships, the influence of the following factors on the collision risk of the ships/machines is further considered:

watchful oversight: the ship lookout negligence is a key element causing the occurrence of ship accidents in water areas, and can further cause the occurrence of problems of ship runaway, ship lookout difficulty, ship control difficulty and the like, so that the ship navigation safety is threatened.

And (3) large wind waves: when a ship sails in a water area and meets extreme weather, such as strong wind, billow or heavy rain, the ship can be difficult to maneuver and look out. The invention thus defines a higher risk of collision for a vessel during its travel in the water, such as when encountering similar extreme weather.

Poor visibility: visibility in the water area will directly influence the vision of boats and ships to watch, and extreme weather's visibility environment, like in heavy fog, heavy rain or the heavy snow environment, can directly increase boats and ships and fan collision risk.

And (3) arranging navigation facilities: the good wind power warning navigation aid facilities are arranged to effectively warn the ship and reduce the navigation risk of the ship in the water area.

Small vessel interference: a large amount of small ship interference exists in the wind power water area, and the collision conflict degree of ships in the water area is increased. Furthermore, due to the nature of fishing vessel operations, navigation regulations may be violated during navigation operations, increasing the complexity of the flow of traffic in the water.

In order to measure the risk degree, all the factor states are designed to obey Bernoulli distribution, and each factor is divided into a yes state and a no state according to the impact degree, namely:

X～B(p,s) (13)

where p is the degree of membership of a particular factor containing state s, as shown in Table 1:

TABLE 1 model factor states

Considering that different factors have different influences on ship navigation risks, the invention adopts a factor weight distribution method. Based on a Mutual Information method (Mutual Information approach) in an Information Entropy theory (Information Entropy theory), the influence degree of different risk factors on the final risk is researched, and then the weight distribution can be carried out on the selected index based on the factor importance degree. The metric function of the information entropy MI is as follows:

in equation 14, C is a constant, and X are the sample information and the total information amount, respectively. Based on three properties (namely monotonicity, nonnegativity and cumulativity) summarized by the information entropy theory, the probability of occurrence of abnormal events (such as extreme weather and poor visibility) is considered to be higher in collected expert data, and the influence on the accident risk is more obvious, so that the factor is endowed with higher weight.

Since the present invention assumes that the parameters all satisfy the bernoulli distribution characteristics, i.e., X to B (p, s), and the normalization constant C is set to 1, the weight w of each factor can be expressed as:

in order to comprehensively calculate the collision probability of a ship and a fan under the influence of multiple factors and solve the heterogeneous problem existing in the fusion of different types of factors, the invention uses an evidence Reasoning method (ER) proposed by Yang equal to 1994 to perform the fusion of heterogeneous data. The method is a multi-standard decision making Method (MCDA), and the method solves the fusion and quantitative calculation problems of various heterogeneous data by using a distributed evaluation criterion generated by an evidence theory algorithm to obtain distribution confidence coefficients and rationality functions of different factors. In the calculation process, the method correlates the collected different 'evidence' states through a utility function, uses a confidence set to describe the membership degree, and uses an inference formula to obtain a final result. The method has the following advantages: the method has the capability of processing heterogeneous data, and allows information in different data formats to be used as model input; reasoning calculation can be carried out under the condition that data are missing, and the missing data are used as uncertainty results for further discussion; qualitative analysis and quantitative evaluation are supported, and the information provided by data sources and evaluation results is more comprehensive.

Let L risk factors of the model, the kth risk factor contains 2 states (yes/no), and the evaluation of the kth factor is recorded as

Weighting w corresponding to the factor _k Satisfy the following requirements

Basic probability weight of the evidence after confidence weight calculation

(basic probability massages) and uncertain probability weights

(uncertainties probability maps) can be found using equations 16 and 17:

the fusion result of the impact of the kth factor and the kth plus 1 factor on the navigation risk of the ship is

Then:

after the fusion result is obtained, normalization processing needs to be performed on the fusion result, as follows:

so far, the distribution P of the collision risk state of the specific single ship with the fan at a certain moment under the influence of multiple factors after normalization can be obtained _j ，P _j E (0, 1). Wherein P is _{Is that} When 1, P indicates that the risk value is at a maximum at that moment _{Whether or not} 1 indicates that there is no risk of collision.

The method for calculating the ship-aircraft collision risk of the offshore wind power water area is used for carrying out case analysis, cases select a certain offshore wind power field on the coastal region of China, and ships pass through a typical scene of the offshore wind power water area to calculate real-time risk change of the ships sailing in the wind power water area. Specific information is described below.

Selecting a wind power plant in a second-stage B area of a horizontal bay of a Putian coast as an object, acquiring data by taking the center of the wind power plant as a ship monitoring area with the diameter of 4 seas, and selecting a typical scene as follows: in the morning of a certain day of September in 2019, the ship runs from the southwest to the northeast through the water area along a south-sun water channel, the time of passing through a wind power water area is about 32 minutes, and one thousand pieces of AIS ship position information are collected in total; the total length of one side, facing a channel, of the wind power plant is about 1.3 nautical miles, the arrangement trend of fans on the north side of the wind power plant is 47.6 degrees, the distance between the fans and the channel is about 0.55 nautical miles, the coordinate of the wind power plant to the fans on the west side of the channel is 25 degrees 09.30N and 119 degrees 22.4E, and the coordinate of the fans on the north side is 25 degrees 10.14N and 119 degrees 23.42E.

According to AIS information, the ship is a common cargo ship, the position of the primary capture ship is 25 degrees 09.15N, 119 degrees 20.44E, the ship speed is 8.6 knots, and the heading is 52.5 degrees. The wind flow conditions in the water area of the day are respectively the true east and the southeast east, the wind speed is Pushi 3 grade, the flow velocity is Dow 4 grade, the visibility at sea exceeds 10 seas at the day, and the visibility is good. The specific information of the ship is obtained by inquiring the registration information of the ship as follows: the ship is 166.5 meters long and 27.4 meters wide, the draught of the ship is 8.8 meters when the ship passes through the ship, the total tonnage of the ship is 20490 tons, the diameter of a propeller is 5.15 meters, the rotating speed is 81 revolutions per minute, the total area of rudder blades is 25.18 square meters, the square coefficient of the ship is 0.846, and the diamond coefficient is 0.808.

In order to calculate the size of the safe interval of the wind power plant, the safe interval of the wind power plant in the scene is subjected to simulation calculation by using the wind power safe interval calculation method provided above. For the distribution density function f (x) of the water area traffic flow, according to the analysis result of the traffic flow in the water area, the spatial distribution of the north ship of the south-sun water channel can be represented by a Gaussian mixture function shown in the table 2, and the distribution function I is f ¹ (x) - (μ ═ 2612.36, σ ═ 180.50, and ω ═ 0.60); distribution function two is f ² (x) - (μ — 1829.95, σ 359.69, ω — 0.36); distribution function three is f ³ (x)～(μ＝3428.26,σ＝194.56,ω＝0.04)。

TABLE 2 south-sun waterway (northbound) ship distribution mixed Gaussian fitting results

According to the statistical result of IALA on past ship accidents all over the world, the annual probability P of mechanical failure of a single ship _F E (0.1,2), the probability of mechanical failure for different types of vessels is shown in table 3. Since the ship to which the present invention is applied is a general cargo ship, P is taken here _F ＝0.75。

TABLE 3 probability of marine main engine failure

Wind and flow deflection parameter P _cw The calculation is carried out according to the actual wind current situation of the water area, according to the existing research on the water area, the annual average flow velocity of the Pu field is 0.5m/s, the included angle between the current direction and the ship course is large, the ship navigation is obviously influenced, and therefore, P is taken _cw ≈3×10 ^-4 。

Based on the above parameter settings, the relationship between the size of the safe area of the wind farm and the risk of the airway can be calculated, and fig. 7 is a graph of the calculation result of the safe boundary distance between the airway and the wind farm in the embodiment of the present invention.

According to the requirement that the annual probability of accidents of foreign offshore wind power water areas does not exceed 0.004, the safe distance between the wind power plant and the navigation path is required to be kept above 0.53 nautical miles, and is about 979 meters.

And calculating the ship reachable set parameters by using the collected ship information and the wind and flow information parameters as input and performing simulation on the ship motion performance by using a ship motion model. The ship motion of the ship is predicted after 150 seconds, 300 seconds and 450 seconds by means of MATLAB software, and as shown in FIG. 8, a schematic diagram of the reach of the ship motion at different moments according to an embodiment of the present invention is shown.

According to the method, the reachable range of the ship within 2.5 minutes is selected as a reachable set of the ship, the farthest distance which the ship can reach under the conditions of straight sailing (the rudder angle is 0), left full rudder (the rudder angle is +25 degrees) and right full rudder (the rudder angle is +25 degrees) is obtained, and as shown in fig. 9, a schematic diagram of a ship motion simulation result of the embodiment of the invention is shown.

Since the AIS data reflects that the fluctuation of the ship speed of the ship in the stage of passing through the wind power water area does not exceed (+ -0.2 section), the ship is assumed to be in a constant speed state in the whole course, namely the reachable set of the ship in the whole course of passing through the water area does not change. Based on the simulation result, the reachable set of the ship in the future 2.5 minutes can be constructed to be M (513.18,69.1 degrees, 8.6 and 2.5), and fig. 10 is a schematic diagram of reachable set parameters of the ship according to the embodiment of the invention.

In order to calculate the dynamic risk of ship navigation, experts need to be invited to evaluate other influencing factors, and the evaluation result of the three experts on the current environment according to the current water area condition is shown in table 4:

TABLE 4 expert evaluation results

In table 4, three experts are provided to evaluate five factors, namely the observation negligence probability, visibility, the condition of the navigation facilities of the wind power plant, the condition of heavy waves and the observation negligence probability in the water area when the ship passes through. Assuming that three experts provide information with the same degree of confidence (i.e., w) ₁ ＝w ₂ ＝w ₃ 0.33), the results of the fusion of the three expert-given evaluations using the evidential reasoning method are given on the right side of the table.

Because the influence degrees of different factors on the ship collision conflict are different, the invention respectively calculates and obtains the relative weights of different factors by using an Information entropy method (Information entropy approach), and when the ship collision degree is taken as a target factor, the weights of the relative target factors of other factors are shown in a table 5:

TABLE 5 entropy and weight distribution results of the factors

According to the above results, the weight distribution results of the factors after the normalization process are as follows: the conflict degree is 0.69, the observation negligence is 0.12, the interference of the small-sized ship is 0.07, the visibility is 0.05, the arrangement condition of navigation aid facilities is 0.03, and the heavy wave is 0.03. And then calculating the dynamic collision probability of the ship at different positions by using an evidence reasoning method. Taking a certain point of the ship in the route as an example, calculating the ratio of the reachable set of the ship to the overlapping area of the wind power safety protection water area to be 0.46, and then expressing the collision degree of the ship at the moment as [ collision degree to (46%, yes), (54%, no) ]. According to table 4, the other parameter distributions are: [ great waves- (3.53%, yes), (96.47%, no) ], [ visibility- (0.00%, yes), (100%, no) ], [ navigation aid layout situation- (20.87%, yes), (79.13%, no) ], [ small vessel interference- (58.18%, yes), (41.82%, no) ], [ lookout neglect- (1.07%, yes), (98.93%, no) ].

By substituting the above results into equations 14 to 18, the collision risk of the ship at a certain time can be calculated. For convenient calculation, the invention carries out probability calculation by means of IDS MulticriteriaAssessor software, and the evidence reasoning steps carried out by using the software are as follows:

the method comprises the following steps: and (3) building a model structure, inputting all influence factors related to the model into software, and defining the model hierarchy. In the invention, the ship collision probability is a target node, and the corresponding influence factors are respectively as follows: [ degree of conflict- (46%, yes), (54%, no) ], [ great storm- (3.53%, yes), (96.47%, no) ], [ visibility- (0.00%, yes), (100%, no) ], [ navigation facility deployment situation- (20.87%, yes), (79.13%, no) ], [ small ship disturbance- (58.18%, yes), (41.82%, no) ], [ lookout negligence- (1.07%, yes), (98.93%, no) ].

Step two: according to the table 5, the weight parameters of different influence factors are set, the weight assignment is performed on each influence factor, and the assignment weight range is set to be 0-1 in the software, which is respectively: the conflict degree is 0.69, the observation negligence is 0.12, the interference of the small ship is 0.07, the visibility is 0.05, the arrangement condition of navigation facilities is 0.03, and the heavy wave is 0.03.

Step three: and inputting the case parameters of different scenes into the constructed model, and calculating the collision risk of the ship under different scenes. If the ship state [ degree of collision (46%), yes), (54%, no) ], [ great storm (3.53%, yes), (96.47%, no) ], [ visibility (0.00%, yes), (100%, no) ], [ navigation aid layout condition (20.87%, yes), (79.13%, no) ], [ small ship interference (58.18%, yes), (41.82%, no) ], [ overlooking negligence (1.07%, yes), (98.93%, no) ] is input into the model at a certain time, the collision risk probability of the scene is 40.45% through evidence reasoning calculation. The ship has higher collision risk under the current environment, and the ship should immediately take measures of turning left to reduce the collision risk.

Repeating the above steps to calculate the risk of the ship position where the ship is located at each moment, respectively, to obtain the risk condition of the ship in the stage of passing through the wind farm, as shown in fig. 11, a graph of the ship-to-aircraft collision risk in the embodiment of the present invention is obtained.

After calculating the risks of the ship at all times, in the case, the dynamic collision and collision heat map conditions of the ship at different times in the whole stage passing through the wind power water area are shown in fig. 12, which is a collision risk change condition of the ship and the aircraft at different times according to the embodiment of the invention.

In fig. 12, the ship approaches the wind farm area at time 0, and the risk of collision between the ship and the fan is 0; the potential collision risk between the ship and the wind power plant gradually rises to about 0.5 along the continuous approach of the ship to the wind power plant along the south water channel and drives past the west-most fan of the wind power plant after 640 s; at the stage of 640 s-1214 s, the ship keeps a heading of 52.5 degrees, sails in the north at the speed of 8.6 knots, and drives in parallel to pass through the wind power plant area, and the collision risk of the ship in the stage reaches 0.64 and is at a higher level; the ship then departs from the wind farm area at time 1214s, the risk of ship collision drops rapidly and departs from the wind farm monitoring water area at time 1883 s.

It can be found that the monitoring ship and the fan have the maximum collision risk after entering a monitoring water area of a wind power plant for about 10 minutes, at the moment, the distance between the ship and the fan on the west side of the wind power plant is only about 800 meters, and no redirection and speed change measures are taken in the subsequent sailing process to reduce the collision risk of the ship and the fan, so that the ship has a higher collision risk when passing through the wind power plant. In combination with the water area environment at that time, the traffic control department can send out early warning to the ship within 10 minutes after the ship drives into the monitored water area, and requires the ship to turn left or increase the passing distance and the like to reduce the potential collision risk between the ship and the wind power plant.

The case analysis can prove that the method for quantifying the ship/machine collision risk in the offshore wind power water area can accurately and effectively quantify the collision risk of the ship in the water area in real time, so that support is provided for controlling the sailing risk of the ship in the water area.

In order to verify the reliability of the model, the method selects a Closest Point of Arrival (CPA) method commonly used for the traditional water area ship collision risk to calculate the ship collision parameters, and uses a fuzzy reasoning method to perform parameter fitting to calculate the collision risk between the ship and the wind power water area.

In the traditional collision risk calculation research, the CPA method is widely used for calculating the collision risk change situation between two ships, and the method also uses various geometric characteristic parameters such as Distance to close Point of Approach (DCPA) and minimum passing Distance to reach Time (TCPA) relative positions to calculate the collision risk besides considering the nearest arrival Point of the ship, so that the CPA method is a very mature risk calculation method in the current ship collision risk research field. However, it should be noted that this method is not suitable for calculating the collision risk between a ship and a range object, because it usually considers two colliding ships as motion particles when calculating the collision risk. To develop comparative experimental analysis, the present invention makes the following assumptions: when the CPA method is used for calculating the collision risk, when a ship approaches a wind power plant area, only the collision risk between the ship and the nearest fan is considered; when the ship drives through a water area near a wind power plant area, only the collision risk condition of the ship and a fan at the nearest point in front of the ship is considered.

The ship collision early warning model provided by Goerlandt and the like is used for comparison, and after the ship collision geometric parameters are obtained, the collision early warning model carries out ship collision risk calculation by using a fuzzy reasoning method. In addition to the geometric collision parameters DCPA and TCPA, the model also takes into account the distance RNG between the vessels and the relative orientation α and β between the two vessels. In addition, corresponding matching rules need to be defined according to state combinations of different geometric collision parameters, and if a certain scene is defined, the relative distance RNG between ships is far, and the ship is risk-free at this time.

The construction of the collision early warning model can be carried out by using a MATLAB Fuzzy Logic Designer-contained tool kit. After the case scenario is input into the model, the risk calculation result can be obtained, as shown in fig. 13, which is a line diagram of a model comparison result according to an embodiment of the present invention.

The ship-aircraft collision geometric model provided by the invention can be found to be capable of better solving the real-time collision risk of the ship in a selected case scene, not only can the influence of multiple factors on the ship-aircraft collision risk under the wind power water area environment be considered, but also the sensitivity is more excellent than that of the traditional fuzzy collision geometric collision model. The main reasons for the analysis include the following: firstly, in the process of calculating the collision risk factor by using the traditional collision geometric model, because the collision risk of a ship and a regional object cannot be considered, the model cannot calculate the risk of the ship in the stage of driving through a wind power plant (sampling points 3-7 in fig. 13), so that the reliability of the risk quantification result of the model in the stage is insufficient; secondly, the influence of a plurality of collision geometrical parameters on the ship collision risk is only considered in the traditional collision geometrical model, and the interference of other environmental influence factors on the ship navigation safety is not considered, so that the risk fluctuation range of the output result of the model is not obvious (lowest 0.42 and highest 0.48), and the comparison result proves that the novel ship-airplane collision risk model provided by the invention has better applicability to a wind power plant; finally, due to the limitation of the number of the matching rules, people are difficult to traverse all ship navigation scenes possibly existing in the wind power plant, so that the traditional collision geometric model has poor dynamic property when used in a wind power water area; on the contrary, the ship-airplane collision risk model provided by the invention overcomes the limitation of the traditional fuzzy matching rule by using the evidence reasoning rule to carry out risk fusion calculation, thereby showing better risk calculation real-time property and sensitivity in the practical process.

The invention provides a ship-machine collision risk calculation method comprehensively considering water area environment and ship motion characteristics, aiming at the problem of quantification of collision risk of a single ship and a fan. Calculating the safe distance between a specific route and a wind power plant and the ship reachable set by using a simulation means by considering the historical traffic flow navigation characteristics of ships in a water area and the specific ship motion characteristics, and calculating the collision conflict parameter by calculating the conflict degree between the ship motion reachable area and the safe area of the wind power plant; on the basis, the influence of various risk factors on the ship navigation safety under the water area environment is considered, the ship navigation risk is calculated by using an evidence reasoning theory, and a practical case is selected to carry out model verification analysis. The result proves that the risk calculation method can dynamically calculate the collision risk of a single ship in the offshore wind power water area in real time; compared with the traditional risk analysis method, the newly proposed risk model has higher sensitivity and reliability, can be suitable for different offshore wind power water area scenes, and has good universality and application prospect, thereby providing theoretical and model support for dynamic real-time risk quantification and collision risk early warning of the ships in the wind power water area.

Example three:

the present invention also provides a device for calculating the risk of a ship-computer collision, as shown in fig. 14, the device comprises a processor 1401, a memory 1402, a bus 1403, and a computer program stored in the memory 1402 and executable on the processor 1401, wherein the processor 1401 comprises one or more processing cores, the memory 1402 is connected to the processor 1401 via the bus 1403, the memory 1402 is used for storing program instructions, and the steps in the above-mentioned method embodiments of the present invention are realized when the processor executes the computer program.

Further, as an executable scheme, the device for calculating the collision risk of the ship computer may be a desktop computer, a notebook, a palm computer, a cloud server and other computing devices. The system/electronic device may include, but is not limited to, a processor, a memory. It will be understood by those skilled in the art that the above-described constituent structures of the system/electronic device are only examples of the system/electronic device, and do not constitute a limitation on the system/electronic device, and may include more or less components than those described above, or some components in combination, or different components. For example, the system/electronic device may further include an input/output device, a network access device, a bus, and the like, which is not limited in this embodiment of the present invention.

Further, as an executable solution, the Processor may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, a discrete Gate or transistor logic device, a discrete hardware component, and the like. The general purpose processor may be a microprocessor or the processor may be any conventional processor or the like, the processor being the control center for the system/electronic device and various interfaces and lines connecting the various parts of the overall system/electronic device.

The memory may be used to store computer programs and/or modules that the processor implements by running or executing the computer programs and/or modules stored in the memory and invoking data stored in the memory, various functions of the system/electronic device. The memory can mainly comprise a program storage area and a data storage area, wherein the program storage area can store an operating system and an application program required by at least one function; the storage data area may store data created according to the use of the mobile phone, and the like. In addition, the memory may include high speed random access memory, and may also include non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), at least one magnetic disk storage device, a Flash memory device, or other volatile solid state storage device.

Example four:

the present invention also provides a computer-readable storage medium, in which a computer program is stored, and the computer program, when executed by a processor, implements the steps of the above-mentioned method according to the embodiment of the present invention.

The system/electronic device integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow in the method according to the embodiments of the present invention may also be implemented by a computer program, which may be stored in a computer-readable storage medium and used by a processor to implement the steps of the above-described embodiments of the method. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer readable medium may include: any entity or device capable of carrying computer program code, recording medium, U-disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), software distribution medium, and the like. It should be noted that the computer readable medium may contain content that is subject to appropriate increase or decrease as required by legislation and patent practice in the jurisdiction.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method of calculating a risk of a ship-to-computer collision for a ship and a wind turbine in an offshore wind farm waters, comprising:

s1, determining a safety region of the wind power plant;

2. The method according to claim 1, wherein the step S1 includes:

P＝P ₁ +P ₂ ；

wherein P is the annual average probability of the risk of a collision of the ship with the aircraft on the route, P ₁ Annual probability of dynamic collision of ship, P ₂ Annual probability of a drifting collision of a ship, N _i Is the total number of ships in the route i, P _ib Probability of an out-of-control event, P, of a vessel in the way i _F Is the failure probability of the ship, P _cw Is the wind and flow deflection probability, P _w Is the wind-induced partial probability, P _c For flow deflection probability, ρ _a Is the density of air, V _a Is the wind speed, A _L The projected area of the wind area on the ship waterline in the ship length direction, L _oA Is the length of the ship, C _a Is the wind pressure resultant coefficient, rho _c Is the density of ocean currents, V _c Is the velocity of the ocean current, A _sl Is the underwater side projection area of the ship, C _c Is the ship flow pressure coefficient, N is the number of sub-distribution functions contained in the Gaussian mixture distribution function, w _j For weight, σ, of sub-distribution function _j For the jth sub-distribution function f (x) _j ) Variance of inner vessel distribution, μ _j For the jth sub-distribution function f (x) _j ) Mean, x, of the distribution of the internal vessels _j For the jth distribution function f (x) _j ) Theta is the course of the ship, N is more than or equal to 3, j belongs to N, and i is a positive integer.

3. The method of claim 2, further comprising: and when the distance is smaller than a preset monitoring distance and larger than the minimum safety distance, calculating the collision risk of the ship and the aircraft in real time according to steps S1-S3.

4. The method of claim 1, wherein the motion reachable set is computed in conjunction with a Manual Model Group (MMG) Model that uses the following formula:

and

acceleration of the ship along an x axis and an y axis respectively,

5. The method of claim 1, wherein the degree of collision conflict is calculated using the formula:

wherein P is the degree of collision conflict, x is the ship position, f (x) _overlapped For overlapping areas of the ship's reachable set with the safety area of the wind farm, M ^t (r) is an achievable set function of the ship over a period of time t, r _portside And r _{starboardside} Respectively a shipThe maximum rudder angle can be used towards the left and right sides.

6. The method of claim 1, wherein when the overlapping region is irregular in shape, the area ratio is calculated using an Otsu gray scale processing algorithm, the area ratio being represented by an inter-class variance ICV, as follows:

ICV＝P _A ^ε ×(g _A -g) ² +P _B ^ε ×(g _B -g) ² ；

7. The method of claim 1, further comprising:

the formula for calculating the weight of the risk factor is as follows:

the calculation formula of the evidence reasoning method is as follows:

wherein L is the number of the risk factors,

in order to be the basis of the probability weights,

in order to not determine the probability weight,

for the result of fusing the impact of the kth risk factor and the (k + 1) th risk factor on the collision risk of the ship and the aircraft, P _j K is a positive integer for the normalized state distribution of the risk of ship-to-aircraft collision.

8. An apparatus for calculating the risk of a collision of a ship's computer, comprising a memory and a processor, the memory storing at least one program, the at least one program being executable by the processor to perform the method of calculating the risk of a collision of a ship's computer according to any one of claims 1 to 7.

9. A computer-readable storage medium, in which at least one program is stored, which at least one program is executable by a processor to carry out a method of calculating a risk of collision of a ship with a computer according to any one of claims 1 to 7.