Ship vulnerability assessment method based on complex network damage tree

Abstract

The invention discloses a ship vulnerability assessment method based on a complex network damage tree. The ship vulnerability assessment method comprises the following steps of 1) dividing damage degree grades of a whole ship according to task execution remaining capability after the ship is damaged; 2) after the damage degree grade of the whole ship is determined, the damage degree of the whole ship is decomposed to each subsystem according to the vitality composition of the whole ship; 3) determining the response value of the equipment according to the task execution capability of the equipment, and calculating the damage probability of the equipment; 4) calculating the system damage probability according to the equipment damage probability; after the equipment damage probability is obtained, the damage states from equipment to the system and from the system to the whole ship are calculated according to the damage tree; and 5) analyzing and quantifying the damage relationship among the equipment, the system and the whole ship by using grey correlation analysis. The complex network damage tree serves as a main body, the method for evaluating the vulnerability of the ship is provided, and the equipment damage probability, the system damage probability, the whole ship damage probability and the correlation degree can be comprehensively evaluated.

Description

Technical Field

[0001] The invention relates to a ship overall design technology, and in particular to a ship vulnerability assessment method based on a complex network damage tree. Background Art

[0002] In the late 1980s, the United Kingdom developed the ship vulnerability assessment program SSVUL, in which the judgment of the degree and consequences of hull and equipment damage adopted an expert system with a database, reaching a high level. In addition, countries such as Australia, Germany, India, Canada, South Korea, Italy and the Netherlands have established specialized ship survivability and vulnerability research institutions.

[0003] The current ship vulnerability assessment technology can only cope with specific situations and is not universal. To address this problem, it is necessary to establish a universal ship vulnerability assessment model. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a ship vulnerability assessment method based on a complex network damage tree in view of the defects in the prior art.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a ship vulnerability assessment method based on a complex network damage tree, comprising the following steps:

[0006] 1) Classify the damage level of the entire ship according to the remaining ability of the ship to perform tasks after damage;

[0007] 2) After determining the damage level of the entire ship, decompose the damage level of the entire ship into each subsystem according to the vitality composition of the entire ship;

[0008] According to the three levels of whole ship, system and equipment, according to the definition and judgment of damage degree of whole ship, system and equipment, the damage degree inference rules between each level are established step by step and the damage tree is drawn;

[0009] The connection logic of each level of damage events in the damage tree includes "AND" gates and "OR" gates;

[0010] 3) Determine the response value of the device based on its ability to perform tasks res , calculate the probability of equipment damage;

[0011] 4) Calculate the system damage probability based on the equipment damage probability;

[0012] After obtaining the equipment damage probability, the damage status from equipment to system and from system to the entire ship is calculated according to the damage tree;

[0013] 5) Use grey relational analysis to analyze and quantify the damage relationship between equipment, systems and the entire ship;

[0014] The system of the whole ship is denoted as E 0 , there are n related devices E under the system 1 ,E 2 ,L,E n , R i Indicates device E i The weight of the damage level, μ i Indicates device E i The degree of membership at a certain level of impairment;

[0015] Then device E i The damage number is d i =R i μ i , so the number of damages to the whole ship is d 0 =R 0 μ 0 ;

[0016] The grey relational space from system to equipment damage is constructed as:

[0017]

[0018] The data is normalized to obtain:

[0019]

[0020] Compute the sequence factor difference:

[0021] Δ i (f)=|e 0 (f)-e i (f)

[0022] Find the maximum and minimum differences:

[0023]

[0024] Calculate the gray correlation coefficient:

[0025]

[0026] In the formula, E 0 is the reference sequence of the whole ship system, E i is a device comparison sequence; ζ∈[0,1] is the identification coefficient; γ(e 0 (f),e i (f)) is e i For 0 The grey correlation coefficient at point f represents the grey correlation factor space under certain conditions. 0 (f) and e i (f) Comparative measure, i.e., the damage of equipment Ei causes the whole ship system E 0 The extent of the injury;

[0027] Gray correlation value calculation:

[0028]

[0029] Grey relational degree γ 0i The value of is in the range of (0,1], which can reflect the device E i Damage to the entire ship system E 0 The inherent correlation characteristics of the damage degree, equal to 1 means that the damage of the device can independently determine the damage of the system, and less than 1 means that the damage of the device can only cause partial loss of system function;

[0030] The grey correlation between damage between equipment and equipment, equipment and each system, and each system and the entire ship is calculated, so as to evaluate the vulnerability of the entire ship through a complex network damage tree.

[0031] According to the above scheme, in step 1), the damage level of the whole ship is divided into the following levels:

[0032] If a ship is abandoned and loses all life force, it is classified as Level 1 damage, i.e. total damage;

[0033] The vessel has lost its maneuverability and mission-performing capability, is floating on the water, is basically unsinkable, and has basically lost its vitality, and is classified as Level 2 damage, i.e., severe damage;

[0034] Damage to ship equipment or components causes the system to lose vitality, but after repair, it still has the ability to maneuver and perform tasks under manual operation and has basic vitality, which is classified as level 3 damage, that is, moderate damage;

[0035] The hull or equipment is partially damaged, but after repair it still has the ability to maneuver and perform tasks under automatic function operation and has relatively complete vitality. It is classified as Level 4 damage, which is light damage.

[0036] According to the above scheme, in step 2),

[0037] When the connection logic is an "AND" gate, the damage probability calculation of the event selects the continuous multiplication or continuous summation of the weight and probability product of the sub-event. The calculation formula used for the damage probability of the event is:

[0038]

[0039] When the connection logic is an "OR" gate, the damage probability of the event is calculated using the following formula:

[0040]

[0041] Where P i is the single event damage probability; δ i is the weight of a single event; Pk is the damage probability of multiple events.

[0042] According to the above scheme, in step 3), the damage probability of the equipment is calculated as follows:

[0043] For the same type of equipment, the response value is ξ res , the damage threshold is ξ 0 ;

[0044] The probability of equipment damage is:

[0045]

[0046] Where a is the mean, σ is the standard deviation; Z = ξ res -ξ 0 .

[0047] According to the above scheme, in step 4), the system damage probability is calculated as follows:

[0048] By weight factor w i To reflect the percentage of the loss of the upper-level event execution function caused by the damage of the lower-level event in the damage tree;

[0049] The damage probability of the series and parallel systems are expressed as:

[0050]

[0051] By calculating the probability transfer between upper and lower level events connected by series-parallel logical relationships in the damage tree, the evaluation of the damage probability from equipment to system and then to the whole ship can be obtained.

[0052] The beneficial effects produced by the present invention are:

[0053] The present invention takes the complex network damage tree as the main body and designs a method for evaluating the vulnerability of ships by combining the grey correlation analysis method with damage tree modeling. It can comprehensively evaluate the equipment damage probability, system damage probability and whole ship damage probability and their correlation, and provide technical means for vitality optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0055] Figure 1 is a method flow chart of an embodiment of the present invention;

[0056] Figure 2 is a schematic diagram of a Class A1 damage tree for a ship according to an embodiment of the present invention;

[0057] Figure 3 4 is a schematic diagram of calculating the equipment damage probability according to an embodiment of the present invention. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0059] like Figure 1 As shown, a ship vulnerability assessment method based on a complex network damage tree includes the following steps:

[0060] 1) Classify the damage level of the entire ship according to the remaining ability of the ship to perform tasks after damage;

[0061] Divided into:

[0062] Level 1 damage means total damage, where the ship is forced to abandon the ship due to sinking or other reasons and completely loses its vitality;

[0063] Level 2 damage means severe damage, where the vessel has lost its maneuverability and mission-performing capability, and is floating on the water surface with basic unsinkability, and has basically lost its vitality;

[0064] Level 3 damage refers to moderate damage, where the equipment or components are damaged, resulting in the system losing vitality, but after repair, it still has the mobility and main defensive combat capabilities under manual operation, which means it has basic vitality;

[0065] Level 4 damage refers to minor damage, where the hull or equipment is partially damaged, but after a short period of repair, it still has the ability to maneuver under automatic function operation and has relatively complete vitality;

[0066] Generally speaking, from the perspective of function and mission, the damage of the whole ship is a combination of the damage of the hull and its systems. Therefore, it is necessary to clearly divide and determine the damage degree and criteria of each level of system or equipment;

[0067] 2) After determining the damage degree of the entire ship, decompose the damage degree of the entire ship into each subsystem according to the vitality composition of the entire ship;

[0068] According to the three levels of the whole ship, system and equipment, according to the damage degree definition and damage event judgment criteria of the whole ship, system and equipment, the damage degree inference rules between each level are established step by step and the damage tree is drawn; the connection logic of the damage events at each level in the damage tree includes "AND" gates and "OR" gates; Figure 2 This is a schematic diagram of the A1 damage tree for ships;

[0069] The connection logic is an "AND" gate. The event probability calculation selects the continuous multiplication or continuous summation of the weight and probability product of the sub-event. The event probability calculation formula is:

[0070]

[0071] The connection logic is an "OR" gate, and the event probability calculation formula is:

[0072]

[0073] Where P i is the single event damage probability; δ i is the weight of a single event; P k is the probability of damage for multiple events;

[0074] 3) Calculate the probability of equipment damage based on the equipment's ability to perform tasks;

[0075] For the same type of equipment, the response value ξ res and the damage threshold ξ 0 All obey normal distribution, so the state equation of the equipment at the critical damage level is defined as:

[0076] Z=ξ res -ξ 0 =0

[0077] In the formula, Z>0 means the equipment is damaged, and Z≤0 means the equipment is intact.

[0078] The probability of equipment damage is Figure 3 As shown, the probability of equipment damage is:

[0079] P d =P(Z>0)=P((ξ res -ξ 0 )>0)

[0080] Since the linear combination of a finite number of normal distribution random variables still has normal distribution characteristics, the damage probability of the equipment can be obtained as:

[0081]

[0082] 4) Calculate the system damage probability;

[0083] After obtaining the equipment damage probability, the damage state from equipment to system and from system to the whole ship is calculated according to the damage tree; the probability of the top event of the damage tree is derived from a series of bottom events through the combined logical relationship of AND gates and OR gates. Since the damage of each equipment has different influences on the damage of the upper system, the weight factor w is used to calculate the probability of the top event of the damage tree. i To reflect the percentage of loss of mission execution function of upper-level events caused by damage to lower-level events in the damage tree.

[0084] The damage probability of series and parallel systems can be expressed as:

[0085]

[0086] By calculating the probability transfer between upper and lower level events connected by series-parallel logical relationships in the damage tree, the evaluation of the damage probability from equipment to system and then to the whole ship can be obtained.

[0087] 5) Use grey relational analysis to analyze and quantify the damage relationship between equipment, systems and the entire ship;

[0088] The system of the whole ship is denoted as E 0 , there are n related devices E under the system 1 ,E 2 ,L,E n , R i Indicates device E i The weight of the damage level, μ i Indicates device E i The degree of membership at a certain level of impairment;

[0089] Then device E i The damage number is d i =R i μ i , so the number of damages to the whole ship is d 0 =R 0 μ 0 ;

[0090] The grey relational space from system to equipment damage is constructed as:

[0091]

[0092] The data is normalized to obtain:

[0093]

[0094] Compute the sequence factor difference:

[0095] Δ i (f)=|e 0 (f)-e i (f)

[0096] Find the maximum and minimum differences:

[0097]

[0098] Calculate the gray correlation coefficient:

[0099]

[0100] In the formula, E 0 is the reference sequence of the whole ship system, E i is a device comparison sequence; ζ∈[0,1] is the identification coefficient; γ(e 0 (f),e i(f)) is e i For 0 The grey correlation coefficient at point f represents the grey correlation factor space under certain conditions. 0 (f) and e i (f) Comparative measure, i.e., the damage of equipment Ei causes the whole ship system E 0 The extent of the damage.

[0101] Gray correlation value calculation:

[0102]

[0103] Grey relational degree γ 0i The value of is in the range of (0,1], which can reflect the device E i Damage to the entire ship system E 0 The inherent correlation characteristics of the damage degree, equal to 1 means that the damage of the device can independently determine the damage of the system, less than 1 means that the damage of the device can only cause partial loss of system function.

[0104] Similarly, the gray correlation degree of damage between equipment and equipment, equipment and each system, and each system and the entire ship can be calculated, so as to evaluate the vulnerability of the entire ship through a complex network damage tree.

[0105] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A ship vulnerability assessment method based on complex network damage tree, characterized in that: The following steps are involved: 1) Classify the damage level of the entire ship according to the remaining ability of the ship to perform tasks after damage; 2) After determining the damage level of the entire ship, decompose the damage level of the entire ship into each subsystem according to the vitality composition of the entire ship; According to the three levels of whole ship, system and equipment, according to the definition and judgment of damage degree of whole ship, system and equipment, the damage degree inference rules between each level are established step by step and the damage tree is drawn; The connection logic of each level of damage events in the damage tree includes "AND" gate and "OR" gate; 3) Determine the response value of the device based on its ability to perform tasks res , calculate the probability of equipment damage; 4) Calculate the system damage probability based on the equipment damage probability; After obtaining the equipment damage probability, the damage status from equipment to system and from system to the entire ship is calculated according to the damage tree; 5) Use grey relational analysis to analyze and quantify the damage relationship between equipment, systems and the entire ship; The whole ship system is recorded as E0, and there are n related equipment E1, E2, L, E n , R i Indicates device E i The weight of the damage level, μ i Indicates device E i The degree of membership at a certain level of impairment; Then device E i The damage number is d i =R i μ i , so the damage number of the whole ship is d0=R0μ0; The grey relational space from system to equipment damage is constructed as: The data is normalized to obtain: Compute the sequence factor difference: Δ i (f)=|e0(f)-e i (f) Find the maximum difference Δ max and the minimum difference Δ min : Calculate the gray correlation coefficient: Where, E0 is the reference sequence of the whole ship system, E i is a comparison sequence of a certain device; ζ∈[0,1] is the identification coefficient; γ(e0(f),e i (f)) is e i The grey correlation coefficient of e0 at point f represents the relationship between e0(f) and e in the grey correlation factor space under certain conditions. i (f) Comparative measure, i.e. the extent to which damage to the equipment Ei causes damage to the entire ship system E0; Gray correlation value calculation: Grey relational degree γ 0i The value of is in the range of (0,1], which can reflect the device E i The inherent correlation characteristics of the damage degree of the whole ship system E0 caused by the damage, equal to 1 means that the damage of the equipment can independently determine the damage of the system, and less than 1 means that the damage of the equipment can only cause partial loss of function of the system; The grey correlation between damage between equipment and equipment, equipment and each system, and each system and the entire ship is calculated, so as to evaluate the vulnerability of the entire ship through a complex network damage tree.

2. The ship vulnerability assessment method based on complex network damage tree according to claim 1 is characterized in that: In step 1), the damage level of the whole ship is divided into the following levels: If a ship is abandoned and loses all life force, it is classified as Level 1 damage, i.e. total damage; The vessel has lost its maneuverability and mission-performing capability, is floating on the water, is basically unsinkable, and has basically lost its vitality, and is classified as Level 2 damage, i.e., severe damage; Damage to ship equipment or components causes the system to lose vitality, but after repair, it still has the ability to maneuver and perform tasks under manual operation and has basic vitality, which is classified as level 3 damage, that is, moderate damage; The hull or equipment is partially damaged, but after repair it still has the ability to maneuver and perform tasks under automatic function operation and has relatively complete vitality. It is classified as Level 4 damage, which is light damage.

3. The ship vulnerability assessment method based on complex network damage tree according to claim 1 is characterized in that: In the step 2), When the connection logic is an "AND" gate, the damage probability calculation of the event selects the continuous multiplication or continuous summation of the weight and probability product of the sub-event. The calculation formula used for the damage probability of the event is: When the connection logic is an "OR" gate, the damage probability of the event is calculated using the following formula: Where P i is the single event damage probability; δ i is the weight of a single event; P k is the damage probability of multiple events.

4. The ship vulnerability assessment method based on complex network damage tree according to claim 1 is characterized in that: In step 3), the damage probability of the equipment is calculated as follows: For the same type of equipment, the response value is ξ res , the destruction threshold is ξ0; The probability of equipment damage is: Where a is the mean, σ is the standard deviation; Z = ξ res -ξ0.

5. The ship vulnerability assessment method based on complex network damage tree according to claim 1 is characterized in that: In step 4), the system damage probability is calculated as follows: By weight factor w i To reflect the percentage of the loss of the upper-level event execution function caused by the damage of the lower-level event in the damage tree; The damage probability of the series and parallel systems are expressed as: By calculating the probability transfer between upper and lower level events connected by series-parallel logical relationships in the damage tree, the evaluation of the damage probability from equipment to system and then to the whole ship can be obtained.

6. An electronic device, characterized in that: include: one or more processors; as well as a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors are caused to execute the method according to any one of claims 1 to 5.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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