A method for evaluating reliability of a ship electric transmission control system

Abstract

The application discloses a kind of ship electric transmission control system reliability evaluation method, comprising: step 1, to ship electric transmission control system, determine system configuration and redundancy configuration;Step 2, according to system configuration and each component redundancy configuration, the reliability modeling of each component and system is carried out;Step 3, first, the minimum path disjoint of component is calculated, and the minimum path disjoint of each component is obtained;Then, the minimum path disjoint calculation of system is carried out, based on the algebraic topology method of multidimensional body description, the minimum path disjoint calculation is carried out to the minimum path obtained, and the disjoint minimum path set is obtained;Step 4, after obtaining the disjoint minimum path set, the reliability of each arc is calculated, and the multidimensional body matrix after disjoint is obtained, and after multiplying column by column, it is added row by row, and the reliability of ship electric transmission control system is solved and obtained.The application can carry out reliability evaluation to electric transmission control system of different configuration and redundancy configuration, and analyze the influence of different configuration and redundancy on system reliability.

Description

Technical Field

[0001] This invention relates to the field of marine mechanical device transmission technology, and in particular to a method for reliability assessment of marine electric control systems. Background Technology

[0002] After decades of development, my country's ship hydraulic systems have formed a relatively fixed power-hydraulic transmission mode, with a basic framework of "centralized hydraulic station - main pipe - control element - user". With the future trend of unmanned and automated operation of ships, the traditional hydraulic transmission mode based on power-hydraulic transmission is gradually being transformed into an electric transmission mode, forming an electric control system with power electric transmission, electric control and electric actuation as its core.

[0003] The core principle of power transmission is that power is transferred through cables and electrical energy. Power-to-electric control refers to the ship's power-to-electric control system, which uses electric motors as the primary driving device and extensively applies electronic and information technologies, making the speed and position control of motors simpler and more convenient, and characterized by speed, accuracy, and stability. Electro-actuators are the specific execution mechanisms at the end of the power-to-electric control system, mainly including electromechanical actuators (EMA), electro-hydraulic actuators (EHA), and electric servo pump control units (EH), etc., featuring high integration and miniaturization, and allowing for more flexible arrangement.

[0004] Because the load users of the fly-by-wire control system are distributed throughout the ship and are diverse in type, redundancy configurations are often required to ensure the safety and reliability of critical load users such as the steering gear, sea valves, and snorkel valves. The specific number and configuration of energy, information, and actuation nodes in the fly-by-wire control system vary depending on the configuration. The ship's fly-by-wire control system is not a simple series or parallel system, but a generalized network with path coupling and reserve relationships. Therefore, it is necessary to analyze the functional coupling relationships of the redundant fly-by-wire control system, construct a complex reliability logic network from underlying events to system success events, and evaluate and analyze the reliability of the fly-by-wire control system under different configurations and conditions, considering various reliability influencing factors. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a reliability assessment method for ship fly-by-wire control systems, addressing the deficiencies in the prior art.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] This invention provides a method for reliability assessment of a ship's fly-by-wire control system, the method comprising the following steps:

[0008] Step 1: For the ship's electric fly-by-wire control system, determine the system configuration and the composition of each subsystem, as well as the redundancy configuration of each actuator, power supply, oil source, and control source.

[0009] Step 2, Reliability Modeling: Based on the system configuration and redundancy configuration of each component, perform reliability modeling for each component and the system;

[0010] Step 3, Minimum Disjointness Calculation: First, perform minimum path disjointness calculation on the components to obtain the minimum paths of each component; then, perform minimum path disjointness calculation on the system. Based on the algebraic topology method of multidimensional volume description, perform disjointness calculation on the obtained minimum paths to obtain the set of disjoint minimum paths.

[0011] Step 4: After obtaining the set of disjoint minimum paths, assuming the failure rate of arc a is λ, then the reliability of this arc at time t is p. a =exp(-λt), unreliability q a =1-exp(-λt); Calculate the reliability of each arc, obtain the multidimensional volume matrix after deintersection, multiply column by column and add row by row to obtain the reliability of the ship's fly-by-wire control system.

[0012] Further, the method of step 1 of the present invention includes:

[0013] The configuration of the ship's electric control system includes: electric steering system + balance system + submersion system; the electric steering system includes: sail rudder + up rudder + down rudder + elevator; actuator type: HA, EHA, EMA; energy type: at least 3 sets of hydraulic power, at least 2 sets of electric power, and at least 3 control units.

[0014] Redundancy configuration includes: electric steering in the ship's fly-by-wire control system configuration; control signal configuration with four redundancy, using three CAN buses plus one hardwired line simultaneously, with control signal transmission guaranteed as long as one bus is working properly, serving as a hot reserve; power supply with dual redundancy, dual power supplies operating simultaneously, serving as a hot reserve; fuel supply with three redundancy, three fuel sources operating simultaneously, serving as a hot reserve; drive unit configuration with EHA, EMA, and HA redundancy, with EHA as the primary, and EMA and hydraulic control as backups, meaning that under normal circumstances only EHA is used, if EHA fails, EMA is used, and if EMA fails, HA is used; finally, the drive unit drives the steering gear to achieve steering surface deflection.

[0015] Furthermore, the component reliability modeling method in step 2 of the present invention includes:

[0016] Command: D1 and D2 are power sources; Y1, Y2, and Y3 are oil sources; E1, E3, E5, and E9 are rudder EHA drive units; E2, E4, E6, and EA are rudder EMA drive units; H1 to H3 are rudder HA drive units; C1 to C3 are control units; B1 to BB are electric ball valves; P1 to P2 are water pumps; EB, ED, EH, and EJ are sea valve and vent valve EHA drive units.

[0017] Due to the logical relationships between actuation nodes E1, E2, and H1, arc E1 must be faulty when arc E2 is usable, and both arc E1 and arc E2 must be faulty when arc H1 is usable. Therefore, the logical function for the success event "The rudder is normal" is:

[0018]

[0019] Reliability modeling is performed on all components based on the above method for establishing the rudder logic function.

[0020] Furthermore, the system reliability modeling method in step 2 of the present invention includes:

[0021] Different actuator combinations and redundancy configurations exist under different configurations. Given the logic functions of each actuator, the logic function for that configuration can be calculated. The logic functions for each configuration are as follows:

[0022]

[0023]

[0024]

[0025]

[0026] W1 = [E B (D1+D2)]C2

[0027] V1 = [E D (D1+D2)]C2

[0028] W2 = [E H (D1+D2)]C2

[0029] V3 = [E J (D1+D2)]C2

[0030] PH=B9B A B B P2(D1+D2)C3

[0031] FL=B1B2B3B4B5B6B7B8P1(D1+D2)C3

[0032] Among them, X1 and X2 are the rudders of the cruciform stern rudder, each with two rudder blades driven by an independent servo motor; X3 is the elevator of the cruciform stern rudder; SR is the sail rudder; W1 and W2 are the sea valves of the two ballast tanks; and V1 and V2 are the vent valves of the two ballast tanks. The successful system events for heading, depth, trim, submersion / surface movement, and balance functions under this configuration are as follows:

[0033] HX=X1+X2 SD=X3+SR ZQ=X1X3

[0034] QF = W1V1W2V3 JH = PH·FL

[0035] Success events for a fly-by-wire control system include:

[0036]

[0037] Furthermore, the method for calculating the minimum non-intersection of components in step 3 of the present invention includes:

[0038] The minimum path set of the electric rudder reliability network is constructed using network analysis, consisting of 7 items, namely: E1D1C1, E1D2C1;

[0039] The electric rudder exhibits a total of 9 arcs, forming the following set:

[0040]

[0041] Describing it using a 9-dimensional multidimensional volume, the minimum path of the rudder network is represented by a set of multidimensional volumes as follows:

[0042]

[0043] To deintersection the minimum paths described in the multidimensional volume, a minimum path deintersection algorithm based on acute product is used, resulting in a total of 7 deintersection minimum path items. E1D2C1.

[0044] Furthermore, the minimum path disjointness algorithm based on acute product in step 3 of the present invention specifically includes:

[0045] A multidimensional volume is an ordered n-tuple where each element corresponds one-to-one with each arc in the network. For an n-tuple describing a multidimensional volume, each element is an arc, and each element takes three states: 1 indicates that the arc is normal, 0 indicates that the arc is faulty, and x indicates that the arc does not appear in the minimum path. This arc is represented by 2, and the number of 2s in the multidimensional volume is called the dimension of the multidimensional volume. Minimum path disjointness calculation based on acute product is used on the multidimensional volume. Assuming there are two multidimensional volumes A and B, the essence of A#B is:

[0046]

[0047] Operations between A and B multidimensional volumes are bitwise operations. Assume A = [a1 a2 … a n-1 a n ], B = [b1 b2 … b n-1 b n The calculation rules for A#B are as follows:

[0048]

[0049] Furthermore, the method for calculating the minimum path non-intersection in step 3 of the present invention includes:

[0050] In this configuration, the fly-by-wire control system comprises 5 power nodes, 3 control nodes, and 16 actuation nodes, with the corresponding node set as follows:

[0051]

[0052] There are 18 non-intersection minimum paths:

[0053]

[0054] Furthermore, the method in step 4 of the present invention includes:

[0055] After obtaining the set of disjoint minimum paths, assuming the failure rate of arc a is λ, then the reliability of arc a at time t is p. a =exp(-λt), unreliability q a =1-exp(-λt); Substitute the reliability of each arc into the obtained deintersecting multidimensional matrix, multiply column by column and add row by row to calculate the reliability of the rudder network; The reliability calculation formula for the above electric rudder component is:

[0056]

[0057] The reliability of the fly-by-wire control system is:

[0058]

[0059] The beneficial effects of this invention are:

[0060] This invention provides a reliability assessment method for ship fly-by-wire control systems. Designers can use this method to assess the reliability of fly-by-wire control systems with different configurations and redundancy settings, analyze the impact of different configurations and redundancy on system reliability, and guide designers to conduct quantitative analysis of fly-by-wire control system reliability. Attached Figure Description

[0061] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0062] Figure 1 This is a schematic diagram of the configuration of a ship's fly-by-wire control system according to an embodiment of the present invention;

[0063] Figure 2 This is a schematic diagram of the electric steering wheel structure according to an embodiment of the present invention;

[0064] Figure 3 This is a schematic diagram of the electric steering node according to an embodiment of the present invention;

[0065] Figure 4 This is a flowchart of the minimum path non-intersection algorithm based on sharp product according to an embodiment of the present invention;

[0066] Figure 5 This is a reliability comparison chart of the fly-by-wire control system according to an embodiment of the present invention. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0068] Example 1

[0069] This implementation will provide a reliability assessment method for the aforementioned fly-by-wire control system, taking the sail rudder + cross rudder (upward rudder + downward rudder + elevator), balance system, and submersion / surface system in the fly-by-wire control system as examples for reliability assessment.

[0070] Step 1: Define the configuration and redundancy allocation

[0071] System configuration: Electric steering system (sail rudder + upper rudder + lower rudder + elevator) + balance system + submersible system; Actuator type: HA, EHA, EMA; Energy type: 3 sets of hydraulic power, 2 sets of electric power, 3 sets of control units.

[0072] See attached Figure 1 E, where the triangle represents i (i = 1, 3, 5...) represents the EHA actuator, with E represented by a circle. i (i = 2, 4, 6…) represents the EMA actuator, and H is represented by a square. i (i = 1, 2, 3…) are the actuators for HA. D i (i = 1, 2) represents two power sources, Y i (i = 1, 2, 3) represent three oil sources, C i (i = 1, 2, 3) are the three controllers: the electric steering system, the fly-by-wire buoyancy system, and the fly-by-wire balancing system.

[0073] Among them, D1 and D2 are power sources, Y1, Y2 and Y3 are oil sources, E1, E3, E5 and E9 are rudder EHA drive devices; E2, E4, E6 and EA are rudder EMA drive devices, H1 to H3 are rudder HA drive devices; C1 to C3 are control units; B1 to BB are electric ball valves; P1 to P2 are water pumps; EB, ED, EH and EJ are sea valve and vent valve EHA drive devices.

[0074] Step 2: Reliability Modeling

[0075] 1. Component Reliability Modeling. In this configuration, the electric servo has a quadruple redundancy in control signals (three CAN buses plus one hardwired line are used simultaneously; the normal operation of one bus is sufficient to guarantee control signal transmission, serving as a hot reserve); dual redundancy in power supply (dual power supplies are used simultaneously, with hot reserves); triple redundancy in oil supply (three oil sources are used simultaneously, with hot reserves); and a triple redundancy configuration for the drive unit (EHA, EMA, and HA are used, with EHA as the primary, and EMA and hydraulic control as backups; i.e., only EHA is used under normal circumstances, EMA is used if EHA fails, and HA is used if EMA fails). Finally, the drive unit drives the servo motor to achieve servo surface deflection. See Appendix. Figure 2 Appendix Figure 3 .

[0076] Due to the logical relationships between actuation nodes E1, E2, and H1, arc E1 must be faulty when arc E2 is usable, and both arc E1 and arc E2 must be faulty when arc H1 is usable. Therefore, the logical function for the success event "The rudder is normal" is:

[0077]

[0078] The reliability modeling of other components is similar to that of the electric steering wheel.

[0079] 2. System Reliability Modeling. Different actuator combinations and redundancy configurations exist under different configurations. Given the logic functions of each actuator, the logic function for that configuration can be calculated. The logic function for this configuration is:

[0080]

[0081]

[0082]

[0083]

[0084] W1 = [E B (D1+D2)]C2

[0085] V1 = [E D (D1+D2)]C2

[0086] W2 = [E H (D1+D2)]C2

[0087] V3 = [E J (D1+D2)]C2

[0088] PH=B9B A BB P2(D1+D2)C3

[0089] FL=B1B2B3B4B5B6B7B8P1(D1+D2)C3

[0090] X1 and X2 are the rudders of the cruciform stern rudder (the cruciform stern rudder has two rudder blades, each driven by an independent servo motor), X3 is the elevator of the cruciform stern rudder, SR is the sail rudder (with auxiliary elevator control function), W1 and W2 are the sea valves of the two ballast tanks, and V1 and V2 are the vent valves of the two ballast tanks. The system success events for heading, depth, trim, submersion / surface movement, and balance functions under this configuration are as follows:

[0091] HX=X1+X2 SD=X3+SR ZQ=X1X3

[0092] QF = W1V1W2V3 JH = PH·FL

[0093] Success events for a fly-by-wire control system include:

[0094] S=HX·SD·ZQ·QF·JH

[0095] =(X1+X2)·(X3+SR)·X3·(W1V1)·(W2V3)·FL·PH

[0096] Step 3: Minimum Path Disjointness Calculation

[0097] 1. Minimum path non-intersection calculation for components

[0098] The minimum path set of the electric rudder reliability network is constructed using network analysis, consisting of 7 items, namely: E1D1C1, E1D2C1.

[0099] The electric rudder exhibits a total of 9 arcs, forming the following set:

[0100]

[0101] Therefore, it is described using a 9-dimensional multidimensional volume, and the minimum path of the rudder network can be represented by a set of multidimensional volumes as follows:

[0102]

[0103] To disjoint the minimum paths described in the above multidimensional volume, a minimum path disjointness algorithm based on acute product is used (see Appendix). Figure 4 .

[0104] A total of 7 projects were obtained to obtain the minimum non-intersection path. E1D2C1.

[0105] 2. System minimum path non-intersection calculation

[0106] In this configuration, the fly-by-wire control system comprises 5 power nodes, 3 control nodes, and 16 actuation nodes, with the corresponding node set as follows:

[0107]

[0108] There are 18 non-intersection minimum paths.

[0109]

[0110] Step 4: Calculate the system's functional reliability

[0111] After obtaining the set of disjoint minimum paths, assuming the failure rate of arc a is λ, then the reliability of arc a at time t is p. a =exp(-λt), unreliability q a =1-exp(-λt). Substituting the reliability of each arc into the deintersected multidimensional matrix obtained above, multiplying column by column and adding row by row, the reliability of the rudder network can be calculated. The reliability calculation formula for the electric rudder component above is:

[0112]

[0113] The reliability of the fly-by-wire control system is:

[0114]

[0115] Substituting the reliability data, the calculation results are shown below. Figure 5 .

[0116] Example 2

[0117] This invention outlines the functional coupling relationships of a redundant fly-by-wire control system, constructs a complex reliability logic network from underlying events to system success events, establishes a reliability network for the fly-by-wire control system, builds a reliability model based on hierarchical redundancy management, and explores a hierarchical recursive reliability solution method. Based on actual requirements and equipment data, different reliability parameters are assigned to each level of the fly-by-wire control system, and the reliability of the fly-by-wire control system is estimated and evaluated in conjunction with its dissimilar redundancy configuration.

[0118] This invention, in conjunction with the application of ship fly-by-wire control systems, constructs a reliability model for ship fly-by-wire control systems under dissimilar redundancy configurations; it proposes a hierarchical recursive method for solving the reliability of ship fly-by-wire control systems, and evaluates and analyzes various factors affecting the reliability of fly-by-wire control systems. The specific steps are as follows:

[0119] Step 1: Define the configuration and redundancy allocation

[0120] Clearly define the configuration of the electric control system, the composition of each subsystem, and the redundancy configuration of each actuator, power supply, oil source, and control source.

[0121] Step 2: Reliability Modeling

[0122] Based on the system configuration and the redundancy configuration of each component, a reliability block diagram and a reliability network diagram of the system and each component are constructed using network analysis.

[0123] Step 3: Minimum Path Disjointness Calculation

[0124] Based on the reliability undirected network graph, we search for the arc sequence between nodes, which is the minimum path between nodes. However, for a path from node 1 to node 2 to be called a minimum path, it must satisfy two conditions: it must be a path; and removing any arc from this arc sequence will no longer result in a path from node 1 to node 2.

[0125] Since there are intersections between the minimum paths, it is necessary to deintersect all minimum paths. Based on the algebraic topology method of multidimensional volume description, the deintersection calculation of the obtained minimum paths is performed.

[0126] A multidimensional volume is an ordered n-tuple where each element corresponds one-to-one with each arc in the network. For the n-tuple describing the multidimensional volume, each element (arc) can take three states: 1 indicates that the arc is normal, 0 indicates that the arc is faulty, and x indicates that the arc does not appear in the minimum path. Therefore, the arc can be either 1 or 0. For convenience, we represent this arc with 2. The number of 2s in the multidimensional volume is called the dimension of the multidimensional volume. We use the minimum path disjointness calculation based on acute product to compute the above multidimensional volume. Assuming there are two multidimensional volumes A and B, the essence of A#B is...

[0127]

[0128] Operations between A and B multidimensional volumes are bitwise operations. Assume A = [a1 a2 … a n-1 a n ], B = [b1 b2 … b n-1 b n The calculation rules for A#B are as follows:

[0129]

[0130] Step 4: Calculate the system's functional reliability

[0131] After obtaining the set of disjoint minimum paths, assuming the failure rate of arc a is λ, then the reliability of arc a at time t is p. a =exp(-λt), unreliability q a=1-exp(-λt). Substituting the reliability of each arc into the deintersected multidimensional volume matrix obtained above, multiplying column by column and adding row by row, the reliability of the rudder network can be calculated.

[0132] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0133] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for reliability assessment of a ship's fly-by-wire control system, characterized in that, The method includes the following steps: Step 1: For the ship's electric fly-by-wire control system, determine the system configuration and the composition of each subsystem, as well as the redundancy configuration of each actuator, power supply, oil source, and control source. Step 2, Reliability Modeling: Based on the system configuration and redundancy configuration of each component, perform reliability modeling for each component and the system; Step 3, Minimum Disjointness Calculation: First, perform minimum path disjointness calculation on the components to obtain the minimum paths of each component; then, perform minimum path disjointness calculation on the system. Based on the algebraic topology method of multidimensional volume description, perform disjointness calculation on the obtained minimum paths to obtain the set of disjoint minimum paths. Step 4: After obtaining the set of disjoint minimum paths, assume that the failure rate of arc a is... Then at time The reliability of this arc is Unreliability The reliability of each arc is calculated, and the resulting multidimensional matrix after deintersection is multiplied column by column and then added row by row to obtain the reliability of the ship's fly-by-wire control system. The method in step 1 includes: The configuration of the ship's electric control system includes: electric steering system + balance system + submersion system; the electric steering system includes: sail rudder + up rudder + down rudder + elevator; actuator type: HA, EHA, EMA; energy type: at least 3 sets of hydraulic power, at least 2 sets of electric power, and at least 3 control units. Redundancy configuration includes: the electric rudder in the ship's fly-by-wire control system configuration has four redundancy control signals, with three CAN buses and one hardwired line used simultaneously. The transmission of control signals is guaranteed as long as one bus is functioning normally, serving as a hot reserve; dual redundancy power supply, with both power sources operating simultaneously, also serving as a hot reserve; triple redundancy fuel supply, with all three fuel sources operating simultaneously, also serving as a hot reserve; and a triple redundancy drive unit configuration of EHA, EMA, and HA, with EHA as the primary unit and EMA and hydraulic control as backups. Under normal circumstances, only EHA is used; if EHA fails, EMA is activated; if EMA fails, HA is activated. Finally, the drive unit drives the steering gear to achieve rudder deflection. The method for component reliability modeling in step 2 includes: Let: D1, D2 are power, Y1, Y2, Y3 are oil source, E1, E3, E5, E9 are rudder EHA drive device; E2, E4, E6, E A For the rudder EMA drive device H1~H3 are rudder HA drive device; C1~C3 are control unit; B1~B B For the electric ball valve; P1~P2 are water pump; E B , E D , E H , E J For the sea valve vent valve EHA drive device; Due to the logical relationships between actuation nodes E1, E2, and H1, arc E1 must be faulty when arc E2 is usable, and both arc E1 and arc E2 must be faulty when arc H1 is usable. Therefore, the logical function for the success event "The rudder is normal" is: Reliability modeling is performed on all components according to the above method for establishing the rudder logic function; The method for system reliability modeling in step 2 includes: Different actuator combinations and redundancy configurations exist under different configurations. Given the logic functions of each actuator, the logic function for that configuration can be calculated. The logic functions for each configuration are as follows: in, This is the rudder in a cruciform stern rudder. The cruciform stern rudder is equipped with two rudder blades, each driven by an independent servo motor. The elevator in a cross-shaped stern rudder. For the sail rudder, For the sea passage valves of the two ballast tanks, For the vent valves of the two ballast tanks; the successful system events for the heading, depth, trim, submersion, and balancing functions under this configuration are as follows: Success events for a fly-by-wire control system include: 。 2. The reliability assessment method for a ship's fly-by-wire control system according to claim 1, characterized in that, The method for calculating the minimum path non-intersection of components in step 3 includes: The minimum path set of the electric rudder reliability network is constructed using network analysis, consisting of 7 items, namely: , , , , , , ; The electric rudder exhibits a total of 9 arcs, forming the following set: Describing it using a 9-dimensional multidimensional volume, the minimum path of the rudder network is represented by a set of multidimensional volumes as follows: To deintersection the minimum paths described in the multidimensional volume, a minimum path deintersection algorithm based on acute product is used, resulting in a total of 7 deintersection minimum path items. , , , , , , .

3. The reliability assessment method for a ship's fly-by-wire control system according to claim 2, characterized in that, The minimum path disjointness algorithm based on acute product in step 3 specifically includes: A multidimensional volume is an ordered n-tuple where each element corresponds one-to-one with each arc in the network. For an n-tuple describing a multidimensional volume, each element is an arc, and each element takes three states: 1 indicates that the arc is normal, 0 indicates that the arc is faulty, and x indicates that the arc does not appear in the minimum path. This arc is represented by 2, and the number of 2s in the multidimensional volume is called the dimension of the multidimensional volume. Minimum path disjointness calculation based on acute product is used on the multidimensional volume. Assuming there are two multidimensional volumes A and B, the essence of A#B is: Operations between A and B multidimensional bodies are bitwise operations, assuming , The calculation rules for A#B are as follows: 。 4. The reliability assessment method for a ship's fly-by-wire control system according to claim 2, characterized in that, The method for calculating the minimum path non-intersection of the system in step 3 includes: In this configuration, the fly-by-wire control system comprises 5 power nodes, 3 control nodes, and 16 actuation nodes, with the corresponding node set as follows: There are 18 non-intersection minimum paths: 。 5. The reliability assessment method for a ship's fly-by-wire control system according to claim 4, characterized in that, The method in step 4 includes: After obtaining the set of disjoint minimum paths, assume the failure rate of arc a is... Then at time The reliability of this arc is Unreliability Substituting the reliability of each arc into the obtained deintersecting multidimensional matrix, multiplying column by column and adding row by row, the reliability of the rudder network is calculated. The reliability calculation formula for the above electric rudder component is as follows: The reliability of the fly-by-wire control system is: 。

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