Method for evaluating reliability of cable

Abstract

The invention relates to a method for evaluating cable reliability, and belongs to the technical field of cable reliability evaluation. The method comprises the following steps: determining a task profile, a corresponding environment profile and profile time according to requirements; the task section is split into a series of tasks, each task is split into a series of basic task sections, and each basic task section corresponds to one environment section and section time; the total failure rate of each basic task profile is obtained based on the sum of the failure rates of the components contained in each basic task profile, and the total reliability of each task is obtained based on the total failure rate of the basic task profile corresponding to each task and the profile time; and when the total reliability of each task is greater than the corresponding threshold value, judging that the reliability of the cable reaches the standard. According to the method, the total failure rate of the cable basic task section and the total reliability of each task are obtained through the failure rate sum of the components and the section time, the cable reliability evaluation time is shortened, the error rate is reduced, and the working efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cable reliability evaluation, and in particular to a method for evaluating cable reliability. Background Art

[0002] Cable products are widely used in electricity, communications, construction and other industries, and are the foundation for my country to promote the construction of an information society. Since cables often work under harsh conditions such as high temperature and high pressure, their reliability is closely related to the quality of the project and the safety of people’s lives and property. Therefore, the reliability research of cables is of great significance.

[0003] The existing methods for evaluating cable reliability are, on the one hand, limited to the evaluation of the cable's own parameters, thus ignoring the impact of different types of environmental stress; on the other hand, they rely on manual calculations by engineers, which is not only time-consuming but also has a high error rate, reducing the efficiency of engineers' work. Summary of the invention

[0004] In view of the above analysis, the present invention aims to provide a method for evaluating cable reliability, so as to solve the problem that the existing cable reliability evaluation ignores different types of environmental stresses, and the evaluation process is cumbersome, time-consuming, and prone to errors, thus resulting in low work efficiency.

[0005] The present invention provides a method for evaluating cable reliability, the method comprising the following steps:

[0006] Determine the mission profile, its corresponding environmental profile, and profile time according to the requirements;

[0007] Split the mission profile into a series of missions, split each mission into a series of basic mission profiles, and each basic mission profile corresponds to an environment profile and profile time;

[0008] The total failure rate of each basic task profile is obtained based on the sum of the failure rates of the components included in each basic task profile. The total reliability of each task is obtained based on the total failure rate and profile time of the basic task profile corresponding to each task. When the total reliability of each task is greater than its corresponding threshold, it is determined that the reliability of the cable meets the standard.

[0009] Furthermore, the failure rate of the components is divided into a working state failure rate and a non-working state failure rate, the working state is a normal state with power on, and the non-working state is a normal state without power on.

[0010] Furthermore, the failure rate in the working state includes the basic failure rate in the working state, the environmental coefficient in the working state, the quality coefficient in the working state, and the component coefficient; the basic failure rate in the working state is the failure rate of components under the action of electrical stress and temperature stress only; the environmental coefficient in the working state is the influence coefficient of environmental stress in different environmental categories other than temperature stress on the failure rate in the working state; the quality coefficient in the working state is the influence coefficient of different quality grades on the failure rate in the working state; the component coefficient is the failure rate of different components related to component types, structures, applications, and performances in the working state.

[0011] Furthermore, the failure rate in the non - working state includes the basic failure rate in the non - working state, the environmental coefficient in the non - working state, and the quality coefficient in the non - working state; the basic failure rate in the non - working state is the failure rate of components related only to component types, structures, and processes in the non - working state; the environmental coefficient in the non - working state is the influence coefficient of environmental stress in different environmental categories on the failure rate in the non - working state; the quality coefficient in the non - working state is the influence coefficient of different quality grades on the failure rate in the non - working state.

[0012] Furthermore, the total reliability of each task is obtained through the following method:

[0013] R iT = exp[-((Σλ i1 )·T i1 +(Σλ i2 )·T i2 +......+(Σλ in )·T in )],

[0014] where R iT is the total reliability of the i - th task, λ in is the total failure rate of the n - th basic task profile in the i - th task, and T in is the profile time corresponding to the n - th basic task profile in the i - th task.

[0015] Furthermore, the total failure rate of each basic task profile is obtained through the following method:

[0016] Σλ in = λ in1 +λ in2 +......+λ inm ,

[0017] where λ inm is the failure rate of the m - th component in the n - th basic task profile of the i - th task.

[0018] Furthermore, the failure rate of components in the working state is obtained through the following method:

[0019] λ mP = λ mb · π mE · π mQ · π mH ,

[0020] where λ mP is the failure rate of the working state of the m-th component, and λ mb is the basic failure rate of the working state of the m-th component, and π mE is the environmental coefficient of the working state of the m-th component, and π mQ is the quality coefficient of the working state of the m-th component, and π mH is the component coefficient of the m-th component.

[0021] Furthermore, the failure rate of the non-working state of the component is obtained by the following method:

[0022] λ mNP = λ mNb · π mNE · π mNQ ,

[0023] where λ mNP is the failure rate of the non-working state of the m-th component, and λ mNb is the basic failure rate of the non-working state of the m-th component, and π mNE is the environmental coefficient of the non-working state of the m-th component, and π mNQ is the quality coefficient of the non-working state of the m-th component.

[0024] Furthermore, the mission profile is the events and states experienced by the cable during the time periods of completing each mission.

[0025] Furthermore, the environmental profile is the category, temperature, humidity, vibration, shock, and electromagnetic interference conditions of the environment where the cable is located during the time period of completing the basic mission.

[0026] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0027] 1. The present invention realizes the automatic calculation of the total reliability of each mission through software, greatly reducing the time of reliability assessment, reducing the error rate, and improving the work efficiency.

[0028] 2. The present invention classifies the relevant data into three categories: manual input, drop-down selection, and automatic update, facilitating parameter adjustment, quick error correction, and avoiding manual repeated calculation, thereby improving the efficiency of cable engineering design.

[0029] 3. When calculating the failure rate of components, the present invention introduces a component coefficient, taking into account the influences of the structures, applications, and performances of different types of components, thereby improving the accuracy of cable reliability assessment.

[0030] 4. The present invention splits the requirements into a series of tasks, and each task is split into a series of basic task profiles, thereby distinguishing between the working state and non-working state of the cable and improving the accuracy of cable reliability assessment.

[0031] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent specification, and some advantages will be obvious from the specification or can be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained from the content specifically pointed out in the specification and the drawings. Description of the Drawings

[0032] The drawings are only for the purpose of showing specific embodiments and are not considered as limiting the present invention. Throughout the drawings, the same reference signs denote the same components.

[0033] Figure 1 is a flowchart of the method for evaluating the reliability of a cable according to an embodiment of the present invention;

[0034] Figure 2 is a schematic diagram of data partitioning according to an embodiment of the present invention. Detailed Embodiments

[0035] The following will specifically describe the preferred embodiments of the present invention with reference to the drawings. The drawings form a part of this application and are used together with the embodiments of the present invention to explain the principles of the present invention, rather than to limit the scope of the present invention.

[0036] A specific embodiment of the present invention discloses a method for evaluating the reliability of a cable. As Figure 1 shown, the method includes the following steps:

[0037] Step S1: Determine the task profile, its corresponding environmental profile, and profile time according to the requirements;

[0038] Step S2: Split the task profile into a series of tasks, each task is split into a series of basic task profiles, and each basic task profile corresponds to an environmental profile and profile time;

[0039] Step S3: Obtain the total failure rate of each basic task profile based on the sum of the failure rates of the components included in each basic task profile, obtain the total reliability of each task based on the total failure rate and profile time of the basic task profiles corresponding to each task, and determine that the reliability of the cable meets the standard when the total reliability of each task is greater than its corresponding threshold.

[0040] Specifically, in step S1, the mission profile is the events and states experienced by the cable during the time periods of completing each mission. The environmental profile is the category, temperature, humidity, vibration, shock, and electromagnetic interference conditions of the environment where the cable is located during the time period of completing the basic mission. The profile time is the time period required for the environmental profile.

[0041] It can be understood that the reliability assessment of the cable is a process of predicting the future reliability of the cable through the design scheme, selected components, circuit and assembly process, and the environmental conditions in which the cable is used during the cable product design stage. The reliability assessment of the cable needs to determine the usage requirements of the cable according to the needs, so as to determine the mission profile, and the mission profile determines the main environmental conditions that the cable will encounter during use, that is, the environmental profile.

[0042] Specifically, in step S2, a mission profile is obtained according to the needs. The mission profile includes at least one mission, and each mission includes at least one basic mission profile. During the profile time corresponding to each basic mission profile, the events and states experienced by the cable remain unchanged. Therefore, each basic mission profile corresponds to an environmental profile.

[0043] Exemplarily, according to requirements, the mission profile is determined as follows: the cable is stored in a warehouse for 5 years after being transported 100 kilometers, and after being transported 200 kilometers and stored in a warehouse for 3 years, the cable is inspected and then operates under harsh conditions for 5 years. The mission profile is split into Mission 1 and Mission 2. Mission 1 is that the cable is stored in a warehouse for 5 years after being transported 100 kilometers, and Mission 2 is that the cable is inspected after being transported 200 kilometers and stored in a warehouse for 3 years, and then operates under harsh conditions for 5 years. Mission 1 is split into 2 basic mission profiles, namely transportation and storage in a warehouse; the environmental profile corresponding to transportation is being in a relatively stable moving state with some vibrations and shocks, and the corresponding profile time is the time corresponding to driving 100 kilometers at an average normal vehicle speed; the environmental profile corresponding to storage in a warehouse is a good ground environment that can maintain normal climatic conditions, with mechanical stress close to zero, good maintenance conditions, and a good warehouse environment with temperature and humidity control, and the corresponding profile time is 5 years. Mission 2 is split into 4 basic mission profiles, namely transportation, storage in a warehouse, inspection, and operation; the environmental profile corresponding to transportation is being in a relatively stable moving state with some vibrations and shocks, and the corresponding profile time is the time corresponding to driving 200 kilometers at an average normal vehicle speed; the environmental profile corresponding to storage in a warehouse is a good ground environment that can maintain normal climatic conditions, with mechanical stress close to zero, good maintenance conditions, and a good warehouse environment with temperature and humidity control, and the corresponding profile time is 3 years; the environmental profile corresponding to inspection is a good ground environment that can maintain normal climatic conditions, with mechanical stress close to zero, good maintenance conditions, and a good warehouse environment with temperature and humidity control, and the corresponding profile time is the average inspection time; the environmental profile corresponding to operation is a harsh ground environment with large temperature differences, high humidity, and mildew, and the corresponding profile time is 5 years.

[0044] Specifically, in step S3, the failure rate of the component is divided into the failure rate in the working state and the failure rate in the non - working state. The working state is the normal power - on state, and the non - working state is the normal non - power - on state.

[0045] It can be understood that the present invention splits the requirements into a series of tasks, and each task into a series of basic mission profiles, thereby distinguishing between the working state and the non - working state of the cable, and improving the accuracy of cable reliability assessment.

[0046] Further, the failure rate in the operating state includes the basic failure rate in the operating state, the environmental coefficient in the operating state, the quality coefficient in the operating state, and the component coefficient; the basic failure rate in the operating state is the failure rate of the component under the action of only electrical stress and temperature stress; the environmental coefficient in the operating state is the influence coefficient of environmental stresses of different environmental categories other than temperature stress on the failure rate in the operating state; the quality coefficient in the operating state is the influence coefficient of different quality grades on the failure rate in the operating state; the component coefficient is the failure rate of different components related to the component type, structure, application, and performance in the operating state.

[0047] Specifically, the environment is divided into different environmental categories according to the climatic conditions, mechanical conditions, biological conditions, chemical conditions, chemically active substance conditions, and mechanically active substance conditions encountered when the cable completes the task. The quality grade is the grade assigned to the quality of the component during the manufacturing, inspection, and screening processes according to the product execution standard or the technical agreement between the supply and demand parties before the component is installed and used. The electrical stress is the ratio of the operating electrical stress of the component to the rated electrical stress.

[0048] Further, the failure rate in the operating state of the component is obtained through the following method:

[0049] λ mP =λ mb ·π mE ·π mQ ·π mH ,

[0050] where, λ mP is the failure rate in the operating state of the m-th component, λ mb is the basic failure rate in the operating state of the m-th component, π mE is the environmental coefficient in the operating state of the m-th component, π mQ is the quality coefficient in the operating state of the m-th component, π mH is the component coefficient of the m-th component.

[0051] Specifically, the above-mentioned coefficients related to the operating state are obtained based on the GJB / Z 299C manual, λ mb can be obtained from Table 5.11.1-1, π mE can be obtained from Table 5.11.1-2, π mQIt can be obtained from Table 5.11.1-3. The components of the cable product include connectors, switches and relays; when the types of components are different, the content included in the component coefficient is different. The component coefficient of the connector includes the contact coefficient, the plugging and unplugging coefficient and the jack structure coefficient; the contact coefficient is the influence coefficient of the number of different contacts on the failure rate in the working state; the plugging and unplugging coefficient is the influence coefficient of the plugging and unplugging frequency of different contacts on the failure rate in the working state; the jack structure coefficient is the influence coefficient of different jack structures on the failure rate in the working state. The component coefficient of the switch includes the contact load coefficient and the switching rate coefficient; the contact load coefficient is the influence coefficient of different contact loads on the failure rate in the working state; the switching rate coefficient is the influence coefficient of different switching rates on the failure rate in the working state. The component coefficient of the relay includes the contact form coefficient, the operating rate coefficient, the rated load coefficient, the application coefficient and the structure coefficient; the contact form coefficient is the influence coefficient of different contact forms on the failure rate in the working state, and the contact forms include single-pole single-throw and single-pole double-throw, etc.; the operating rate coefficient is the influence coefficient of different moving rates on the failure rate in the working state; the rated load coefficient is the influence coefficient of different load currents on the failure rate in the working state; the application coefficient is the influence coefficient of different application scenarios on the failure rate in the working state, and the application scenarios include high power, thermal delay, etc.; the structure coefficient is the influence coefficient of different structures on the failure rate in the working state, and the structures include dry reed and wet reed.

[0052] It can be understood that when calculating the failure rate of the components, the present invention considers the influence of the structure, application and performance of different types of components by introducing the component coefficient, and considers the influence of different types of environmental stresses by introducing the environmental coefficient, thereby improving the accuracy of the cable reliability assessment.

[0053] Exemplarily, the failure rate of the connector in the working state is obtained by the following method:

[0054] λ mP =λ mb ·π mE ·π mQ ·π mP ·π mK ·π mC ,

[0055] wherein, π mP is the contact coefficient of the m-th connector, π mK is the plugging and unplugging coefficient of the m-th connector, and π mC is the jack structure coefficient of the m-th connector.

[0056] Specifically, λ mb (direct parameter) can be obtained from Table 5.11.1-1 of GJB / Z 299C manual. λ mbDepends on two factors: the operating temperature (derived parameter 1) and the insulating mounting plate material (derived parameter 2). The operating temperature is the sum of the ambient temperature (derived parameter 3) and the temperature rise of the insulating mounting plate material of the connector (derived parameter 4). The temperature rise values of the insulating mounting plate material corresponding to different contact specifications (derived parameter 5) and different contact currents (derived parameter 6) can be obtained from Table 5.11.1-6. The number of connector pairs (derived parameter 7) is the number of pairs of connectors. For a single connector, the number of connector pairs is 0.5.

[0057] The specific classification of the insulating mounting plate material can be obtained from Table 5.11.1-7. This parameter depends on the insulating material of the connector itself, that is, it comes from the product specification of the connector. The ambient temperature depends on the ambient temperature under the actual working condition, that is, it comes from the requirement. The contact specification comes from the product specification of the connector. The contact current depends on the actual working current, that is, it comes from the requirement. The number of connector pairs comes from the requirement or the engineer's design scheme.

[0058] π mP Can be obtained from Table 5.11.1-4, π mK Can be obtained from Table 5.11.1-5, π mC Can be obtained from Table 5.11.1-8. The number of contacts is the number of contacts actually used. This parameter comes from the requirement or the engineer's design scheme. The jack structure depends on the characteristics of the connector itself, that is, it comes from the product specification of the connector.

[0059] It can be seen that the operating state failure rate of 1 connector needs to be retrieved back and forth from different tables, involving 6 direct parameters and 7 derived parameters. And cable products often contain N connectors, which means involving 6N direct parameters and 7N derived parameters. Therefore, manual retrieval is not only time-consuming but also extremely error-prone.

[0060] Furthermore, the non-operating state failure rate includes the non-operating state basic failure rate, the non-operating state environmental coefficient, and the non-operating state quality coefficient; the non-operating state basic failure rate is the failure rate of the component in the non-operating state that is only related to the component type, structure, and process; the non-operating state environmental coefficient is the influence coefficient of the environmental stress of different environmental categories on the non-operating state failure rate; the non-operating state quality coefficient is the influence coefficient of different quality grades on the non-operating state failure rate.

[0061] Furthermore, the non-operating state failure rate of the component is obtained by the following method:

[0062] λ mNP =λ mNb ·π mNE ·π mNQ ,

[0063] Among them, λ mNP is the non-operating state failure rate of the m-th component, λ mNb is the basic non-operating state failure rate of the m-th component, π mNE is the non-operating state environmental factor of the m-th component, π mNQ is the non-operating state quality factor of the m-th component.

[0064] Specifically, the above non-operating state related coefficients are obtained based on the GJB / Z 108A manual. λ mNb can be obtained from Table 5.11.1-1, π mNE can be obtained from Table 5.11.1-2, π mNQ can be obtained from Table 5.11.1-3. The basic non-operating state failure rate depends on the shape and process of the connector, that is, it comes from the product specification of the connector. The non-operating state quality factor also comes from the product specification of the connector.

[0065] Furthermore, the total failure rate of each basic mission profile is obtained by the following method:

[0066] Σλ in = λ in1 + λ in2 +......+ λ inm ,

[0067] Among them, λ inm is the failure rate of the m-th component in the n-th basic mission profile of the i-th mission.

[0068] Exemplarily, if a cable consists of 5 connectors, then Σλ in = λ in1 + λ in2 +......+ λ in5 , where λ in1 is the failure rate of the 1st connector.

[0069] Furthermore, the total reliability of each mission is obtained by the following method:

[0070] R iT = exp[-((Σλ i1 )·T i1 +(Σλ i2 )·T i2 +......+(Σλ in )·T in )],

[0071] Among them, R iT is the total reliability of the i-th mission, λ inis the total failure rate of the nth basic mission profile in the ith mission, T in is the profile time corresponding to the nth basic mission profile in the ith mission.

[0072] Specifically, the total reliability of each mission needs to consider all the basic mission profiles included in each mission. Since each basic profile corresponds to an environmental profile and a profile time, the total failure rate of each basic mission profile also needs to be multiplied by the profile time. Since each mission is independent, each mission has a corresponding reliability threshold, which is set by the upper-level product. When the total reliability of all missions is greater than its corresponding threshold, it is determined that the reliability of the cable meets the standard. Otherwise, parameters need to be modified and redesigned until the reliability of the cable meets the standard.

[0073] It can be understood that whether it is the failure rate in the working state or the non-working state of components, most parameters need to be selected from existing manuals, and the amount of data that needs to be manually input is not much. Therefore, in order to facilitate parameter adjustment, quickly try and error, and avoid manual repeated calculations, improving the efficiency of cable engineering design, as Figure 2 shown, the present invention classifies relevant data into three categories: manual input, drop-down selection, and automatic update. Among them, the drop-down selection data are parameters provided in the manual or parameters with a clear selection range, the manual input data are parameters specified by requirements or parameters not clearly defined in the manual, and the automatic update data are data whose results can be automatically calculated through given parameters. Based on the above data classification, the present invention can set the manual input data and drop-down selection data through software, and automatically update the total reliability of each mission, thereby realizing the automatic calculation of the total reliability of each mission, greatly reducing the time of reliability assessment, reducing the error rate, and improving the work efficiency.

[0074] Compared with the prior art, the beneficial effects of the method for evaluating the reliability of a cable provided by the present invention are as follows:

[0075] 1. The present invention realizes the automatic calculation of the total reliability of each mission through software, greatly reducing the time of reliability assessment, reducing the error rate, and improving the work efficiency.

[0076] 2. The present invention classifies relevant data into three categories: manual input, drop-down selection, and automatic update, facilitating parameter adjustment, quickly trying and error, and avoiding manual repeated calculations, improving the efficiency of cable engineering design.

[0077] 3. The present invention introduces a component coefficient when calculating the failure rate of components, considering the influences of the structures, applications, and performances of different types of components, improving the accuracy of cable reliability assessment.

[0078] 4. The present invention splits the requirements into a series of tasks, and each task into a series of basic task profiles, thereby distinguishing between the working state and non-working state of the cable and improving the accuracy of cable reliability assessment.

[0079] Those skilled in the art can understand that all or part of the processes of implementing the methods of the above embodiments can be completed by instructing relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. Among them, the computer-readable storage medium is a magnetic disk, an optical disc, a read-only memory or a random access memory, etc.

[0080] As described above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for evaluating the reliability of a cable, characterized in that, The method includes the following steps: Determine the mission profile, its corresponding environment profile, and profile time according to requirements; Split the mission profile into a series of tasks, each task into a series of basic mission profiles, and each basic mission profile corresponding to an environment profile and profile time; Obtain the total failure rate of each basic mission profile based on the sum of the failure rates of the components included in each basic mission profile, obtain the total reliability of each task based on the total failure rate and profile time of the basic mission profiles corresponding to each task, and determine that the reliability of the cable meets the standard when the total reliability of each task is greater than its corresponding threshold.

2. The method for evaluating the reliability of a cable according to claim 1, characterized in that, The failure rate of the component is divided into the failure rate in the working state and the failure rate in the non-working state. The working state is the normal power-on state, and the non-working state is the normal non-power-on state.

3. The method for evaluating the reliability of a cable according to claim 2, characterized in that, The failure rate in the working state includes the basic failure rate in the working state, the environmental coefficient in the working state, the quality coefficient in the working state, and the component coefficient; the basic failure rate in the working state is the failure rate of the component under the action of only electrical stress and temperature stress; the environmental coefficient in the working state is the influence coefficient of environmental stresses of different environmental categories other than temperature stress on the failure rate in the working state; the quality coefficient in the working state is the influence coefficient of different quality grades on the failure rate in the working state; the component coefficient is the failure rate related to the component type, structure, application, and performance of different components in the working state.

4. The method for evaluating the reliability of a cable according to claim 2, characterized in that, The failure rate in the non-working state includes the basic failure rate in the non-working state, the environmental coefficient in the non-working state, and the quality coefficient in the non-working state; the basic failure rate in the non-working state is the failure rate of the component related only to the component type, structure, and process in the non-working state; the environmental coefficient in the non-working state is the influence coefficient of environmental stresses of different environmental categories on the failure rate in the non-working state; the quality coefficient in the non-working state is the influence coefficient of different quality grades on the failure rate in the non-working state.

5. The method for evaluating the reliability of a cable according to claim 1, characterized in that, The total reliability of each task is obtained by the following method: R iT = exp[-((Σλ i1 )·T i1 +(Σλ i2 )·T i2 +......+(Σλ in )·T in )], Among them, R iT is the total reliability of the i-th task, λ in is the total failure rate of the n-th basic mission profile in the i-th task, and T in is the profile time corresponding to the n-th basic mission profile in the i-th task.

6. The method for evaluating the reliability of a cable according to claim 1, characterized in that, The total failure rate of each basic mission profile is obtained by the following method: Σλ in = λ in1 + λ in2 +...... + λ inm , where, λ inm is the failure rate of the m-th component in the n-th basic mission profile of the i-th mission.

7. The method for evaluating the reliability of a cable according to claim 2, characterized in that, The failure rate of the component in the working state is obtained by the following method: λ mP = λ mb · π mE · π mQ · π mH , where, λ mP is the working state failure rate of the m-th component, λ mb is the basic failure rate of the working state of the m-th component, π mE is the environmental coefficient of the working state of the m-th component, π mQ is the quality coefficient of the working state of the m-th component, π mH is the component coefficient of the m-th component.

8. The method for evaluating the reliability of a cable according to claim 2, characterized in that, The failure rate of the component in the non-working state is obtained by the following method: λ mNP = λ mNb · π mNE · π mNQ , where λ mNP is the non-operating state failure rate of the m-th component, λ mNb is the non-operating state basic failure rate of the m-th component, π mNE is the non-operating state environmental factor of the m-th component, π mNQ is the non-operating state quality factor of the m-th component.

9. The method for evaluating the reliability of a cable according to claim 1, characterized in that, The mission profile is the events and states experienced by the cable during the time period of completing each task.

10. The method for evaluating the reliability of a cable according to claim 1, characterized in that, The environment profile is the category, temperature, humidity, vibration, shock, and electromagnetic interference situation of the environment where the cable is located during the time period of completing the basic task.

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