A ship vulnerability assessment method based on complex network damage tree

Abstract

The application discloses a kind of ship vulnerability evaluation methods based on complex network damage tree, comprising the following steps: 1) according to the remaining ability of ship after damage to perform task, the damage degree grade of whole ship is divided;2) after determining the damage degree grade of whole ship, according to the vitality of whole ship, the damage degree of whole ship is decomposed to each subsystem;3) according to the ability of equipment to perform task, the response value of equipment is determined, and the damage probability of equipment is calculated;4) according to the damage probability of equipment, the system damage probability is calculated;after obtaining the damage probability of equipment, the damage state from equipment to system, from system to whole ship is calculated according to damage tree;5) the damage relationship between equipment, system and whole ship is analyzed and quantified by using grey correlation analysis.The present application takes complex network damage tree as the main body, provides a kind of method for evaluating ship vulnerability, can comprehensively evaluate equipment damage probability, system damage probability and whole ship damage probability and its correlation degree.

Description

Technical Field

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

[0002] The UK developed the Ship Vulnerability Assessment (SSVUL) program in the late 1980s. This program utilizes an expert system with a database to assess the extent and consequences of hull and equipment damage, achieving a high level of sophistication. Furthermore, countries such as Australia, Germany, India, Canada, South Korea, Italy, and the Netherlands have established specialized research institutions on ship survivability and vulnerability.

[0003] The current ship vulnerability assessment technology can only deal 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 response to the defects in the existing technology.

[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 to perform tasks after the ship is damaged;

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

[0008] According to the three levels of ship, system and equipment, and based on the definition and judgment of damage degree of 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 damage events at all levels 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 the equipment to the system and from the system to the entire ship is calculated according to the damage tree;

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

[0014] 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;

[0015] Then device E i The number of damages is d i =R i μ i , so the damage number of the whole ship is d0=R0μ0;

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

[0017]

[0018] Normalizing the data yields:

[0019]

[0020] Compute the serial factor difference:

[0021] Δ i (f)=|e0(f)-e i (f)

[0022] Find the maximum and minimum differences:

[0023]

[0024] Calculate the gray relational coefficient:

[0025]

[0026] Where, E0 is the reference sequence of the whole ship system, E i is a device comparison sequence; 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 entire ship system E0 is caused by damage to the equipment Ei;

[0027] Gray relational value calculation:

[0028]

[0029] Gray relational degree γ 0i The value of is in the range of (0,1], which can reflect the device E iThe inherent correlation characteristic of the damage level of the entire ship system E0 caused by the damage is equal to 1, which means that the damage of the equipment can independently determine the damage of the system. If it is less than 1, it means that the damage of the equipment can only cause partial loss of system function.

[0030] The gray correlation degree of damage between equipment, equipment and various systems, and various systems 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 entire ship is divided into the following levels:

[0032] If a vessel 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 capabilities, is floating on the water, is essentially unsinkable, and has essentially lost its life force. This is classified as Level 2 damage, or severe damage.

[0034] Damage to ship equipment or components results in the loss of system vitality, but after repair, the ship still has the ability to maneuver and perform tasks under manual operation and has basic vitality, which is classified as Level 3 damage, i.e. moderate damage;

[0035] If 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 probability of damage of a single event; δ i is the weight of a single event; P k 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 destruction threshold is ξ0;

[0044] The probability of equipment damage is:

[0045]

[0046] Where a is the mean, σ is the standard deviation; Z = ξ res -ξ0.

[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 upper-level event execution function loss caused by the damage of the lower-level event in the damage tree;

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

[0050]

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

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

[0053] Based on the complex network damage tree, this paper designs a method for assessing ship vulnerability by combining grey correlation analysis with damage tree modeling. This method can comprehensively evaluate the equipment damage probability, system damage probability, and whole ship damage probability and their correlation, providing a technical means for optimizing vitality. 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 flow chart of a method according to an embodiment of the present invention;

[0056] Figure 2 This 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 solutions 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 intended to limit the present invention.

[0059] like Figure 1As 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 to perform tasks after the ship is damaged;

[0061] Divided into:

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

[0063] Level 2 damage is severe damage, where the vessel has lost its maneuverability and mission-performing capabilities, is floating on the water, and is essentially unsinkable, with essentially no life force.

[0064] Level 3 damage refers to moderate damage. The damage to the equipment or components causes the system to lose 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, with the hull or equipment partially damaged. After a short period of repair, the ship 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 entire ship is a combination of the damage to the hull and its various systems. Therefore, it is necessary to clearly divide and determine the damage degree and judgment criteria of each level of system or equipment;

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

[0068] According to the three levels of ship, system and equipment, and based on the damage degree definitions and damage event judgment criteria of the ship, system and equipment, the damage degree inference rules between each level are established step by step and a damage tree is drawn; the connection logic of 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 probability of damage of a single event; δ i is the weight of a single event; Pk 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 ξ0 obey the normal distribution, so the state equation of the equipment at the critical damage level is defined as:

[0076] Z=ξ res -ξ0=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 as follows Figure 3 As shown, the probability of equipment damage is:

[0079] P d =P(Z>0)=P((ξ res -ξ0)>0)

[0080] Since the linear combination of a finite number of normally distributed 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 status 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 combination logic relationship of AND gate and OR gate. Since the degree of influence of each equipment damage on the upper system damage is different, 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 task 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 and parallel logical relationships in the damage tree, an assessment of the damage probability from equipment to system and then to the entire ship can be obtained.

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

[0088] The whole ship system is recorded as E0, and there are n related equipment E1, E2, L, E n , Ri 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 number of damages is d i =R i μ i , so the damage number of the whole ship is d0=R0μ0;

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

[0091]

[0092] Normalizing the data yields:

[0093]

[0094] Compute the serial factor difference:

[0095] Δ i (f)=|e0(f)-e i (f)

[0096] Find the maximum and minimum differences:

[0097]

[0098] Calculate the gray relational coefficient:

[0099]

[0100] Where, E0 is the reference sequence of the whole ship system, E i is a device comparison sequence; 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, that is, the extent to which damage to the entire ship system E0 is caused by damage to the equipment Ei.

[0101] Gray relational value calculation:

[0102]

[0103] Gray relational degree γ 0i The value of is in the range of (0,1], which can reflect the device E iThe inherent correlation characteristics of the damage degree of the entire ship system E0 caused by damage. If it is equal to 1, it means that the damage of the equipment can independently determine the damage of the system. If it is less than 1, it means that the damage of the equipment can only cause partial loss of function of the system.

[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 the 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 such 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 to perform tasks after the ship is damaged; 2) After determining the damage level of the entire ship, the damage level of the entire ship is decomposed into each subsystem according to the vitality composition of the entire ship; According to the three levels of ship, system and equipment, and based on the definition and judgment of damage degree of 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 damage events at all levels in the damage tree includes "AND" gates and "OR" gates; 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 the equipment to the system and from the system to the entire ship is calculated according to the damage tree; 5) Use grey relational analysis to analyze and quantify the damage relationships among 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 number of damages 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: Normalizing the data yields: Compute the serial factor difference: Find the maximum difference Δ max and the minimum difference Δ min : Calculate the gray relational coefficient: Where, E0 is the reference sequence of the whole ship system, E i is a device comparison sequence; 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 entire ship system E0 is caused by damage to the equipment Ei; Gray relational value calculation: Gray relational degree γ 0i The value of is in the range of (0,1], which can reflect the device E i The inherent correlation characteristic of the damage level of the entire ship system E0 caused by the damage is equal to 1, which means that the damage of the equipment can independently determine the damage of the system. If it is less than 1, it means that the damage of the equipment can only cause partial loss of system function. The gray correlation degree of damage between equipment, equipment and various systems, and various systems 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 entire ship is divided into the following levels: If a vessel 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 capabilities, is floating on the water, is essentially unsinkable, and has essentially lost its life force. This is classified as Level 2 damage, or severe damage. Damage to ship equipment or components results in the loss of system vitality, but after repair, the ship 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; If 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 probability of damage of a single event; 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 upper-level event execution function loss caused by the damage of the lower-level event in the damage tree; The damage probability of series and parallel systems are expressed as: By calculating the probability transfer between upper and lower level events connected by series and parallel logical relationships in the damage tree, an assessment of the damage probability from equipment to system and then to the entire 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 enabled to perform 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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