Ship damage assessment method based on state space geometric analysis

Abstract

The present invention relates to a ship damage assessment method based on state space geometric analysis. The method is based on the principle of system engineering and on the functional relationship components of the ship. The deductive method of the damage state tree is used to analyze the functional association relationship between the ship components. The hesitant fuzzy set theory and Choquet integral are used as a powerful aggregation function for fuzzy elements to analyze the components and the functional relationship, thereby solving the information fusion problem of the component damage state, achieving the development of an information fusion algorithm that is closer to the actual damage state transfer process, and can be used for quantitative analysis and assessment of the damage state of the ship, thereby providing auxiliary reference for decision makers of combat command. The present invention provides a method for evaluating the damage state of the ship for ship designers and combat command decision makers, and guides the damage assessment of the ship.

Description

Technical Field

[0001] The present invention relates to a ship damage assessment method based on state space geometric analysis, which can be applied to the field of ship damage assessment, providing a method for evaluating the damage status of ships for ship designers and combat command decision makers, and also providing auxiliary reference for combat command decision makers on ship damage assessment. Background Art

[0002] The damage of missiles to ship targets is an extremely complex process, which involves the performance and structural characteristic parameters of the attacked target. How to accurately describe the damage state of ship targets is an important issue facing scientific researchers. With the increasingly severe situation at sea, the assessment of the damage state of ship targets has received more and more attention. However, since the ship is a comprehensive system, the vitality of the ship (the state after damage) must be coordinated with the attack capability of the ship. Therefore, the assessment of vitality has received more and more attention.

[0003] In order to evaluate the vitality of the ship, Liu Jinxiang et al. conducted "Ship vitality assessment based on improved fuzzy hierarchical analysis method" and adopted an improved fuzzy hierarchical analysis method to establish a triangular fuzzy judgment matrix, determine the weights of relevant factors between levels, and calculate the weight ranking of each subsystem. The evaluation results can reflect the working conditions of the ship systems, but the analysis process cannot reflect the relationship between components, and the calculation process also fails to reflect the dependency between component functions, and cannot quantitatively analyze and evaluate the damage status of the ship. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings and defects of the prior art and provide a method for quantitatively analyzing and evaluating the damage status of a ship. The present invention is a ship damage assessment method based on state space geometric analysis. The method is based on the principle of system engineering and is based on the relationship between the functional relationship components of the ship. The deductive method of the damage status tree is used to analyze the functional association relationship between the components of the ship. The hesitant fuzzy set theory and Choquet integral are used as powerful aggregation functions of fuzzy elements to analyze the components and functional relationships, thereby solving the information fusion problem of the component damage status and obtaining a quantitative assessment of the ship damage status.

[0005] In order to achieve the above tasks, the present invention proposes a ship damage assessment method based on state space geometric analysis, which includes the following steps:

[0006] Based on the practical experience of ship damage assessment status, for the damage of conventional ships, the number of components defined is generally not more than 50, and the weight value of each component is 0.1-0.8; for the damage of ships, the number of components fused each time is not more than 7, and the value of the fusion component algorithm coefficient α is 0.3-0.8, which can obtain damage results that meet the actual situation. At the same time, commonly used anti-ship missiles use 1-8 rounds to cover the damage status of ships from light, severe to destruction.

[0007] 1. A ship damage assessment method based on state space geometric analysis includes the following steps:

[0008] Step 1: Determine the representation method of damage assessment information and define related sets and variables: Assume that the damage of the ship involved in the assessment is A = {a i |i=1,2,…,m},,a i The damage of a ship, m is 1 to 8, considering the number of times the ship strikes and the different states after each strike; the component set is E = {e j |i=1,…,n},e j is a component in the component set, j is a value not greater than 50; the component weight set is w = {w j |i=1,…,n},w j It is component e j The weight value is between 0.1 and 0.8, which is divided according to the functional importance of the ship components. If the value is too small or too large, it has no evaluation significance. The damage state set of the evaluation object is u = {u j |j=1,2,…,n}, its value is between 0 and 1, and u j With e j One to one correspondence;

[0009] Step 2, let μ(E i ) is the relative importance of each subset of component sets, 2 E is the power set of the set of components E, then there exists a measure function, μ:2 E →[0,1], using Choquet integration method:

[0010]

[0011] In the formula, F(u σ(j) ) is the numerical calculation result related to the damage state of the component itself, σ(·) is the order of the damage state results; in a certain evaluation process, σ(·) satisfies the relationship 0≤f(u σ(1) )≤f(u σ(2) )≤…≤f(u σ(n) ), and U j = {u σ(j) ,u σ(j+1) ,…,uσ(n)} is the n-j+1th largest subset of the damage state set U and U n+1 ≠φ;

[0012] Step 3: The relationship between the damage state of the evaluated component and the damage state of its subordinate components is expressed as

[0013] U=f(u1,u2,…,u j ,…,u n ) (2)

[0014] And the remaining state quantity of the component and its subordinate components satisfies:

[0015]

[0016] Take u1,u2,…,u j ,…,u n Construct an n-dimensional coordinate system for the coordinates, where n is the number of component state fusions, not greater than 7. All possible damage states of the component correspond to points in the n-dimensional coordinate system. These points constitute the state space [0,1] that describes the component damage state. n ; Let any state of the component be U(a i ), then in the state space, it corresponds to U(a i ) is the point (u i1 ,u i2 ,…,u ij ,…,u in ), where 0≤u ij ≤1; when U(a i ) is the remaining state of the component after being damaged, U max With U(a i ) The distance d(a) between the corresponding points i ) can be used to indicate the similarity between any damaged state of a component and its normal state; d(a i ) can be used to measure the degree of damage to a component, that is, the amount of residual state U that is reduced by the component due to damage max ﹣U(a i );

[0017] Step 4: The distance d(a) between any damaged state of the component and the corresponding point in the normal state i ), in the form of Euclidean distance

[0018]

[0019] In the formula, w j is the weight of the jth component, s k is the weight given by the kth expert, I={1,1,…,1}, and the number of 1s is d(I,h ij) is the distance between any hesitant fuzzy element and the entire set I. Substituting (1) into (4) yields:

[0020]

[0021] Step 5: The function of the remaining state quantity of any damage state of the fusion component is:

[0022]

[0023] The fusion component algorithm coefficient α is set to 0.3-0.8 based on practical experience. The evaluated ship damage status is more in line with reality. The information fusion algorithm (6) can be used to quantitatively analyze and evaluate the ship damage status.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The ship damage assessment method based on state space geometric analysis provided by the present invention solves the information fusion problem of the damage status of ship components, thereby achieving quantitative analysis and assessment of the damage status of the ship. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The embodiment of the present invention shows the transfer relationship of the damage state of a three-component system in the state space;

[0027] Figure 2 is the functional dependency relationship between the three modules of the ship in the embodiment of the present invention;

[0028] Figure 3 is a component damage state transition path under various damage modes in the embodiment of the present invention, wherein 1-4-2 is a path of a certain correlation function;

[0029] Figure 4 It is the damage tree structure in the embodiment of the present invention.

[0030] Figure 5 These are the four striking positions in the embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the present invention is further described in detail below with reference to embodiments and drawings.

[0032] The purpose of the present invention is to provide a ship damage assessment method based on state space geometric analysis. The method takes the damage of a certain type of ship as an example. After the ship is hit in a certain mission, a total of three experts jointly assess the damage status of the ship to reduce the assessment error of a single expert.

[0033] In order to achieve the above tasks, the present invention proposes a ship damage assessment method based on state space geometric analysis, which includes the following steps:

[0034] Step 1: Determine the representation method of damage assessment information and define related sets and variables: Assume that the damage of the ship involved in the assessment is A = {a i |i=1,2,…,m}; therefore the component set is E={e j |j=1,…,n}, the component weight set is w={w j |j=1,…,n}; the damage state set of the evaluation object is u={u j |j=1,2,…,n}, and u j With e j One to one correspondence;

[0035] Among them, m = 4 (for four damage conditions), when the first damage state is merged, n = 26 (for example Figure 4 As shown, X1~X 26 It is the lowest level component in the ship component system);

[0036] Step 2, let μ(E i ) is the relative importance of each subset of component sets, 2 E is the power set of the set of components E, then there exists a measure function μ:2 E →[0,1], using Choquet integration method:

[0037]

[0038] In the formula, F(u σ(j) ) is the numerical calculation result related to the damage state of the component itself, σ(·) is the order of the damage state results; in a certain evaluation process, σ(·) satisfies the relationship 0≤f(u σ(1) )≤f(u σ(2) )≤…≤f(u σ(n) ), and U j = {u σ(j) ,u σ(j+1) ,…,u σ(n)} is the n-j+1th largest subset of the damage state set U and U n+1 ≠φ;

[0039] Step 3: The relationship between the damage state of the evaluated component and the damage state of its subordinate components is expressed as

[0040] U=f(u1,u2,…,u j ,…,u n ) (2)

[0041] And the remaining state quantity of the component and its subordinate components satisfies:

[0042]

[0043] Take u1,u2,…,u j ,…,u n Construct an n-dimensional coordinate system for the coordinates, then all possible damage states of the component correspond to points in the n-dimensional coordinate system, and these points constitute the state space [0,1] that describes the damage state of the component. n ; Let any state of the component be U(a i ), then in the state space, it corresponds to U(a i ) is the point (u i1 ,u i2 ,…,u ij ,…,u in ), where 0≤u ij ≤1; when U(a i ) is the remaining state of the component after being damaged, U max With U(a i ) The distance d(a) between the corresponding points i ) can be used to indicate the similarity between any damaged state of a component and its normal state; d(a i ) can be used to measure the degree of damage to a component, that is, the amount of residual state U that is reduced by the component due to damage max ﹣U(a i ).

[0044] Step 4: Express d(a) in the form of Euclidean distance i ), then the distance d(a) between the corresponding point of any damaged state and normal state of the component i ) can be expressed as

[0045]

[0046] In the formula, w j is the weight of the jth component, s k is the weight given by the kth expert. The number of experts k is 3. I={1,1,…,1}, and the number of 1s is d(I,h ij ) is the distance between any hesitant fuzzy element and the entire set I. Substituting (1) into (4) yields:

[0047]

[0048] Step 5: The function of the remaining state quantity of any damage state of the fusion component is:

[0049]

[0050] The fusion component algorithm coefficient α is set to 0.7.

[0051] Figure 5 The red circles in the middle are the hit points of the four strikes on the ship. These four strikes are used as four typical cases for damage assessment.

[0052] For the four damage assessment situations, the experts evaluate the status of each damaged component in each damage situation and the prior probability of damage. After obtaining the hesitant fuzzy elements of the experts on the damage situation, the hesitant fuzzy element scores of the damage situation of each component are substituted into equations (4) and (5), and the residual state quantity u for the damage state of each component of the ship can be obtained. i As shown in Table 1.

[0053] Table 1 Remaining state quantity of each component damage state

[0054]

[0055] Combination Figure 4 , substituting the evaluation data in Table 1 into formula (6), α is taken as 0.7 according to the historical experience of this embodiment, and finally the damage evaluation result U of the ship as a whole and each system can be obtained, and the residual state quantity of the damage state of each functional system is obtained as shown in Table 2.

[0056] Table 2 Remaining state quantity of each functional system damage state

[0057]

[0058] By analyzing the residual state of each functional damage state of the above-mentioned ships, we can know that:

[0059] a. In Case 1, the ship is in a destroyed state. The remaining state of the damaged state is 0, but it is not sunk and can be repaired;

[0060] b. In Case 2, the ship is in a damaged state. The remaining state of the damaged state is 0.8932, which means it is in a lightly damaged state and can continue to perform all combat missions;

[0061] c. In Case 3, the ship is in a damaged state. The remaining state of the damaged state is 0.8431, which means it is in a lightly damaged state. It can continue to perform most combat missions, but the anti-ship combat mission is seriously affected;

[0062] d. In Case 4, the ship is in a destroyed state. The remaining state of the damaged state is 0, and it may be sunk and cannot be repaired.

[0063] The causes of the above damage assessment conclusions are analyzed. Case 2 and Case 3 are in a state of slight damage, and the residual state quantities of the damage state are 0.8932 and 0.8431 respectively. It can be seen from the damage state values ​​of the ship systems in Tables 1 and 2 that the reasons for the four damage assessment results are very different. Although the ships in Case 1 and Case 4 are in a destroyed state, the damage to the functional systems in Case 4 is not serious. The command and control system and weapon system of the ship in Case 4 are only in a state of slight damage, and the power system and navigation system are almost not damaged. However, since the ship's supporting platform has been destroyed, the ship can no longer support the functions of all other functional systems, which means that the ship has suffered a fatal damage incident and is likely to be sunk. Therefore, the ship is in a destroyed state. The support platform and power system of the ship in Case 1 are intact, which means that the ship has not suffered a fatal damage incident. However, since the ship's navigation system and command and control system have been severely damaged, the ship cannot perform any combat functions before being repaired. In Table 2, the failure of the command and control system in Case 1 limits the function of the weapon system. Therefore, although the ship is in a destroyed state, it is possible to repair it because it has not been sunk.

[0064] The ships in Case 2 and Case 3 were both slightly damaged, which means that they could still perform most combat missions. The basic support modules of the ships in Case 2 and Case 3 were intact, which means that no fatal damage occurred to the ships. The command and control system, weapon system and navigation system of the ship in Case 2 were slightly damaged, but as shown in Table 1, all the functional skills of the ship continued to function, so the ship could continue to perform its combat functions and complete combat missions. In Case 3, only the weapon system and navigation system of the ship were slightly damaged, and the state of the navigation system was better than that of the navigation system of the ship in Case 2, but the residual state of the ship's damaged state in Case 3 was lower than that of the ship's damaged state in Case 2. As shown in Table 1, the anti-ship system of the ship in Case 3 was severely damaged, and one of the anti-ship missile systems could hardly function anymore, which seriously affected the anti-ship function of the ship. As an important function for ships to perform combat missions, the anti-ship function has a high weight, which affects the overall residual state of the ship's weapon system. This is the fundamental reason why the residual state of the ship's damage state in Case 3 is lower than that in Case 2.

Claims

1. A ship damage assessment method based on state space geometric analysis includes the following steps: Step 1: Determine the representation method of damage assessment information and define related sets and variables: Assume that the damage of the ship involved in the assessment is , is a certain damage to the ship; the component set is , is a component in the component set; the component weight set is , It is a component The weight value of the evaluation object is ,and u j and e j One to one correspondence; Step 2: Set is the relative importance of each subset of component sets, Is the complete set of components E power set, then there exists a measure function , using Choquet integration method: （1） In the formula, is the numerical calculation result related to the component damage state itself, is the order of the damage status results; in a certain evaluation process, Satisfaction relationship ,and Damage state set U No. n - j +1 largest subset and ; Step 3: The relationship between the damage status of the evaluated component and the damage status of its subordinate components is expressed as: （2） And the remaining state quantity of the component and its subordinate components satisfies: （3） by Build for coordinates n dimensional coordinate system, n is the component state fusion number, not greater than 7, then all possible damage states of the component correspond to n The points in the dimensional coordinate system constitute the state space [0,1] that describes the damage state of the component n ; Let any state of the component be , then in the state space it corresponds to The point is ,in ;when is the remaining state of the component after it is damaged, and Distance between corresponding points It can be used to indicate the similarity between any damaged state of a component and its normal state; It can be used to measure the degree of damage to a component, that is, the amount of residual state reduced by the component due to damage is ; Step 4: The distance between any damaged state of the component and the corresponding point in the normal state , in the form of Euclidean distance: （4） In the formula, w j For the j The weight of the components, s k For the k The weight given by experts, , and the number of 1s is , For arbitrary hesitant fuzzy elements and the whole set I The distance between them, substituting (1) into (4) yields: （5） Step 5: The function of the remaining state quantity of any damage state of the fusion component is: （6） in α is the fusion component algorithm coefficient. The information fusion algorithm (6) can be used to quantitatively analyze and evaluate the damage status of the ship.

2. The ship damage assessment method based on state space geometric analysis according to claim 1 is characterized in that: The damage to the ships involved in the assessment is , m is a natural number from 1 to 8; 0.1~0.8, j is a natural number between 4 and 50, It is 0~1.

3. The ship damage assessment method based on state space geometric analysis according to claim 1 is characterized in that: The fusion component algorithm coefficients α The value is 0.3~0.8.

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