Maintenance test sample distribution method simultaneously considering mechanical fault and electronic fault

Abstract

The invention discloses a maintainability test sample distribution method considering mechanical faults and electronic faults at the same time. The method comprises the steps that firstly, the expected life and the total sample size of a test product are determined; then determining a fault rate function of each electronic device and each mechanical structural member in the test product along with time, and integrating the fault rates according to a distribution time axis to obtain sample weight factors of each electronic device and each mechanical structural member; summing the sample weight factors of the electronic devices and the mechanical structural parts to obtain a total sample weight factor; and finally, calculating the proportion of each sample factor in the total weight factor of the sample to obtain the distribution coefficient of each sample, and multiplying the distribution coefficient of each sample by the total sample size to obtain the distribution quantity of each sample. The method solves the problem of maintainability test sample size distribution of the electromechanical equipment comprising a mechanical structural part and an electronic device, can provide data reference conforming to the actual use condition for the maintainability test, and is beneficial to improving the maintainability design of electromechanical products.

Description

Technical Field

[0001] The present invention relates to the field of electronic information technology, and in particular to a method for allocating maintainability test samples taking both mechanical failures and electronic failures into consideration. Background Art

[0002] With the rapid development of electromechanical systems, more and more electromechanical products are put into industrial production and daily life. The losses caused by equipment downtime caused by electromechanical equipment maintenance have a great impact on industrial production and daily life. Therefore, electromechanical equipment with good maintainability is very important for corporate activities and social operations.

[0003] In the maintainability design of electromechanical products, maintainability tests are the main means of feedback on product maintainability design defects. Good maintainability test design can early discover the direction of improving product maintainability. Before conducting maintainability tests, test sample allocation is required, and sample allocation should be as consistent as possible with the distribution of product failures in actual maintenance. Since electronic failures and mechanical failures have different mechanisms, their statistical manifestations are quite different, and the failures of electromechanical equipment are mainly electronic failures. Therefore, the current distribution of maintainability test samples for electromechanical equipment only considers the impact of electronic device failures, and does not include the impact of mechanical structural failures.

[0004] However, mechanical structural parts may suffer from obvious wear, fatigue, corrosion and other failure phenomena during use. Therefore, when allocating maintainability samples, the impact of mechanical structural parts failure needs to be considered to be more in line with actual usage conditions.

[0005] A large amount of experimental data shows that the life distribution of mechanical structural parts and electronic devices is completely different. Therefore, it is difficult to allocate samples while considering both mechanical failure samples and electronic failure samples. Summary of the invention

[0006] The purpose of the present invention is to propose a maintainability test sample allocation method that conforms to the fault distribution of products in actual maintenance and can provide data references that conform to actual usage conditions for maintainability tests.

[0007] The technical solution to achieve the purpose of the present invention is: 1. A method for allocating maintainability test samples taking into account both mechanical failures and electronic failures, characterized in that it comprises the following steps:

[0008] Step 1: Confirm the expected life of the test product;

[0009] Step 2: Determine the total sample size of the test product;

[0010] Step 3, determine the failure rate function of each electronic device in the test product over time;

[0011] Step 4, determine the failure rate function of each mechanical structural component in the test product over time;

[0012] Step 5, calculating the time axis integral of the failure rate distribution of each electronic component with the expected life of the test equipment as the cut-off time, and obtaining the sample weight factor of each electronic component;

[0013] Step 6, calculating the time axis integral of the failure rate distribution of each mechanical structural component with the expected life of the test equipment as the cut-off time, and obtaining the sample weight factor of each mechanical structural component;

[0014] Step 7: Sum the sample weight factors of each electronic device and the sample weight factors of each mechanical structure to obtain a total sample weight factor;

[0015] Step 8, calculate the proportion of the sample factors of each electronic device and each mechanical structure part to the total sample weight factor, and obtain the distribution coefficient of each sample;

[0016] Step 9: Calculate the product of each sample allocation coefficient and the total sample size, round the result to the nearest integer, and obtain the sample allocation amount of each electronic component and each mechanical structural part.

[0017] Furthermore, the expected life of the confirmation test product described in step 1 is as follows:

[0018] Confirm the expected life of the product based on the product contract or product life estimate.

[0019] Furthermore, the total sample size of the test product determined in step 2 is as follows:

[0020] According to the actual situation of the test product itself and Table A1 in GJB 2072-1994 "Maintainability Test and Evaluation Standard", obtain the total sample size information of the test product.

[0021] Furthermore, the failure rate function of each electronic device in the test product over time as described in step 3 is specifically as follows:

[0022] The life of electronic devices follows an exponential distribution. The failure rate of each electronic device in the test product is a constant and does not change with the use time. Therefore, the failure rate function λ of the i-th electronic device is i ′(t) is:

[0023] λ i ′(t)=D i

[0024] Where, t represents working time; D i is a constant, representing the failure rate of the ith electronic component; the failure rate of each electronic component is determined according to GJB / Z 299C-2006 “Handbook of Reliability Prediction of Electronic Equipment”.

[0025] Furthermore, the failure rate function of each mechanical structural component in the test product over time as described in step 4 is specifically as follows:

[0026] The life of mechanical components follows the Weibull distribution. The failure rate of each mechanical component in the test product changes with the use time. Therefore, the failure rate function λ of the i-th mechanical component is i ″(t) is:

[0027]

[0028] Wherein, t represents the working time; m is the shape parameter of the Weibull distribution; η is the location parameter of the Weibull distribution; the Weibull distribution parameters are determined and estimated through a large number of experiments, observation data or component failure database information.

[0029] Furthermore, the calculation described in step 5 is to integrate the failure rate distribution time axis of each electronic device with the expected life of the test equipment as the cut-off time to obtain the sample weight factor of each electronic device, which is as follows:

[0030]

[0031] Among them, a i ′ represents the sample weight factor of the i-th electronic device; T represents the product life; λ i ′(t) represents the failure rate function of the i-th electronic device; t represents the working time.

[0032] Furthermore, the calculation described in step 6 integrates the failure rate distribution time axis of each mechanical structural component with the expected life of the test equipment as the end time to obtain the sample weight factor of each mechanical structural component, which is as follows:

[0033]

[0034] Among them, a i ″ represents the sample weight factor of the i-th mechanical structure; T represents the product life; λ i ″(t) represents the failure rate function of the i-th mechanical structure component; t represents the working time.

[0035] Furthermore, the sample weight factors of each electronic device and the sample weight factors of each mechanical structure part described in step 7 are summed to obtain a total sample weight factor, which is as follows:

[0036]

[0037] Where c represents the total sample weight factor; p′ represents the number of electronic devices; a i′ represents the sample weight factor of the i-th electronic device; p″ represents the number of mechanical structural parts; a i ″ represents the sample weight factor of the i-th mechanical structure component.

[0038] Furthermore, the proportion of the sample factors of each electronic device and each mechanical structure part to the total sample weight factor is calculated in step 8 to obtain the distribution coefficient of each sample, which is as follows:

[0039]

[0040] Among them, e i ′ represents the sample distribution coefficient of the i-th electronic device; e i ″ represents the sample distribution coefficient of the i-th mechanical structure component.

[0041] Furthermore, the product of the calculated sample allocation coefficient and the total sample size in step 9 is rounded off to obtain the sample allocation amount of each electronic device and each mechanical structure part, as follows:

[0042] g i ′=e i ′×N

[0043] g i ″=e i ″×N

[0044] Among them, g i ′ represents the sample allocation of the i-th electronic device; e i ′ represents the sample distribution coefficient of the i-th electronic device; N represents the total sample size; g i ″ represents the sample distribution amount of the i-th mechanical structure component; e i ″ represents the sample distribution coefficient of the i-th mechanical structure component.

[0045] Compared with the prior art, the present invention has the following significant advantages: (1) It simultaneously considers the influence of mechanical failure and electronic failure on the maintainability test to allocate maintainability test samples, which can solve the problem of sample allocation of maintainability tests for electromechanical equipment containing mechanical structural parts and electronic devices, conform to the fault distribution of products in actual maintenance, and provide data references that conform to actual usage conditions for maintainability tests; (2) It can improve the maintainability test plan of electromechanical equipment containing mechanical structural parts and electronic devices, which helps to improve the maintainability design of electromechanical products. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a flow chart of the method for allocating maintainability test samples taking both mechanical failure and electronic failure into consideration according to the present invention.

[0047] Figure 24 is a graph showing the change of the failure rate of electronic devices over time in an embodiment of the present invention.

[0048] Figure 3 4 is a graph showing the change of the failure rate of a mechanical structural component over time in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0050] Combination Figure 1 The present invention provides a method for allocating maintainability test samples that considers both mechanical failures and electronic failures, comprising the following steps:

[0051] Step 1: Confirm the expected life of the test product as follows:

[0052] Confirm the expected life of the product based on the product contract or product life estimate.

[0053] Step 2: Determine the total sample size of the test product as follows:

[0054] According to the actual situation of the test product itself and Table A1 in GJB 2072-1994 "Maintainability Test and Evaluation Standard", obtain the total sample size information of the test product.

[0055] Step 3: Determine the failure rate function of each electronic device in the test product over time, as follows:

[0056] The life of electronic devices follows an exponential distribution. The failure rate of each electronic device in the test product is a constant and does not change with the use time. Therefore, the failure rate function λ of the i-th electronic device is i ′(t) is:

[0057] λ i ′(t)=D i

[0058] Where, t represents working time, in h; D i is a constant, which indicates the failure rate of the ith electronic device, and its unit is h. The failure rate of each electronic device is determined according to GJB / Z 299C-2006 “Handbook of Reliability Prediction of Electronic Equipment”.

[0059] Step 4: Determine the failure rate function of each mechanical structural component in the test product over time, as follows:

[0060] The life of mechanical components follows the Weibull distribution. The failure rate of each mechanical component in the test product changes with the use time. Therefore, the failure rate function λ of the i-th mechanical component is i ″(t) is:

[0061]

[0062] Wherein, t represents the working time, the unit is h; m is the shape parameter of the Weibull distribution; η is the location parameter of the Weibull distribution; the Weibull distribution parameters can be determined and estimated through a large number of experiments, observation data or component failure database information.

[0063] Step 5: Calculate the time axis integral of the failure rate distribution of each electronic component with the expected life of the test equipment as the cutoff time, and obtain the sample weight factor of each electronic component, as follows:

[0064]

[0065] Among them, a i ′ represents the sample weight factor of the i-th electronic device; T represents the product life, in h; λ i ′(t) represents the failure rate function of the ith electronic device; t represents the working time in h.

[0066] Step 6: Calculate the time axis integral of the failure rate distribution of each mechanical structural component with the expected life of the test equipment as the cutoff time, and obtain the sample weight factor of each mechanical structural component, as follows:

[0067]

[0068] Among them, a i ″ represents the sample weight factor of the i-th mechanical structure; T represents the product life, in units of h; λ i ″(t) represents the failure rate function of the i-th mechanical structure component; t represents the working time, the unit is h.

[0069] Step 7: Sum the sample weight factors of each electronic device and the sample weight factors of each mechanical structure to obtain the total sample weight factor, as follows:

[0070]

[0071] Where c represents the total sample weight factor; p′ represents the number of electronic devices; a i ′ represents the sample weight factor of the i-th electronic device; p″ represents the number of mechanical structural parts; a i ″ represents the sample weight factor of the i-th mechanical structure component.

[0072] Step 8: Calculate the proportion of sample factors of each electronic device and each mechanical structure part to the total sample weight factor, and obtain the distribution coefficient of each sample, as follows:

[0073]

[0074] Among them, ei ′ represents the sample distribution coefficient of the i-th electronic device; e i ″The sample distribution coefficient of the i-th mechanical structure component.

[0075] Step 9: Calculate the product of each sample allocation coefficient and the total sample size, round the result to the nearest integer, and obtain the sample allocation amount of each electronic device and each mechanical structure part, as follows:

[0076] g i ′=e i ′×N

[0077] g i ″=e i ″×N

[0078] Among them, g i ′ represents the sample allocation of the i-th electronic device; e i ′ represents the sample distribution coefficient of the i-th electronic device; N represents the total sample size; g i ″ represents the sample distribution amount of the i-th mechanical structure component; e i ″ represents the sample distribution coefficient of the i-th mechanical structure component.

[0079] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0080] Example

[0081] This embodiment takes a certain type of power module as an example to explain in detail a method for allocating maintainability test samples that takes both mechanical failures and electronic failures into consideration.

[0082] The power module consists of five parts: filter circuit board, surge suppression circuit board, power supply board, power supply shell, and power supply internal support structure. The filter circuit board, surge suppression circuit board, and power supply board are electronic components; the power supply shell and power supply internal support structure are mechanical components. Therefore:

[0083] p′=3

[0084] p″=2

[0085] Step 1: Confirm the expected life of the test product as follows:

[0086] According to the development contract, the expected life of the power module is T=20000h.

[0087] Step 2: Determine the total sample size of the test product as follows:

[0088] According to the actual situation of the power module itself and Table A1 in GJB 2072-1994 "Maintainability Test and Evaluation Standard", the total sample size of this product test is determined to be 30;

[0089] Step 3: Determine the failure rate function of each electronic device in the test product over time, as follows:

[0090] The life of the filter circuit board, surge suppression circuit board and power supply board conforms to the exponential distribution. According to GJB / Z 299C-2006 "Electronic Equipment Reliability Prediction Manual", the failure rate of the filter circuit board, surge suppression circuit board and power supply board is confirmed, and the failure rate function of each electronic component over time is obtained, such as Figure 2 shown.

[0091] The failure rate function formula of the filter circuit board is:

[0092] λ1′(t)=14.5×10 -6 / h

[0093] The failure rate function formula of the surge suppression circuit board is:

[0094] λ2′(t)=10.5×10 -6 / h

[0095] The failure rate function formula of the power supply board is:

[0096] λ3′(t)=8.25×10 -6 / h

[0097] Step 4: Determine the failure rate function of each mechanical structural component in the test product over time, as follows:

[0098] The life of the power supply shell and the internal supporting structure of the power supply conforms to the Weibull distribution. The Weibull distribution parameters of the power supply shell and the internal supporting structure of the power supply are obtained according to the information of the component failure database, and the failure rate function of the power supply shell and the internal supporting structure of the power supply over time is obtained, such as Figure 3 shown.

[0099] The failure rate function formula of the power supply shell is:

[0100]

[0101] The failure rate function formula of the internal supporting structure of the power supply is:

[0102]

[0103] Step 5: Calculate the time axis integral of the failure rate distribution of each electronic component with the expected life of the test equipment as the cutoff time, and obtain the sample weight factor of each electronic component, as follows:

[0104] Sample weight factors for the filter board are:

[0105]

[0106] Sample weighting factors for a surge suppression board are:

[0107]

[0108] Sample weight factors for the power board are:

[0109]

[0110] Step 6: Calculate the time axis integral of the failure rate distribution of each mechanical structural component with the expected life of the test equipment as the cutoff time, and obtain the sample weight factor of each mechanical structural component, as follows:

[0111] Sample weight factors for Powershell are:

[0112]

[0113] The sample weight factors for the internal supporting structure of the power supply are:

[0114]

[0115] Step 7: Sum the sample weight factors of each electronic device and the sample weight factors of each mechanical structure to obtain the total sample weight factor, as follows:

[0116]

[0117] Step 8: Calculate the proportion of sample factors of each electronic device and each mechanical structure part to the total sample weight factor, and obtain the distribution coefficient of each sample, as follows:

[0118] Sample distribution coefficients for filter boards are:

[0119]

[0120] Sample distribution factors for surge suppression boards are:

[0121]

[0122] Sample distribution factors for a power supply board are:

[0123]

[0124] Sample distribution coefficients for Power Shell are:

[0125]

[0126] The sample distribution coefficient of the internal supporting structure of the power supply is:

[0127]

[0128] Step 9: Calculate the product of each sample allocation coefficient and the total sample size, round the result to the nearest integer, and obtain the sample allocation amount of each electronic device and each mechanical structure part, as follows:

[0129] The sample allotment for the filter board is:

[0130]

[0131] After rounding, the sample allocation amount of the filter circuit board is 11;

[0132] Sample allotments for surge suppression circuit boards are:

[0133]

[0134] After rounding, the sample allocation for the surge suppression circuit board is 8;

[0135] The distribution of the power supply board sample is:

[0136]

[0137] After rounding, the sample allocation of the power supply board sample is 6;

[0138] Sample allocations for powershell are:

[0139]

[0140] After rounding, the sample allocation of the power shell is 3;

[0141] The sample allocation for the internal support structure of the power supply is:

[0142]

[0143] After rounding, the sample allocation for the internal supporting structure of the power supply is 2.

[0144] It can be seen from this embodiment that the present invention simultaneously considers the impact of mechanical failures and electronic failures on maintainability tests to distribute maintainability test samples, can solve the problem of sample size distribution for maintainability tests of electromechanical equipment containing mechanical structural parts and electronic components, conforms to the distribution of product failures in actual maintenance, can provide data references that conform to actual usage conditions for maintainability tests, can improve the maintainability test scheme of electromechanical equipment containing mechanical structural parts and electronic components, and helps to improve the maintainability design of electromechanical products.

[0145] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for allocating maintainability test samples that considers both mechanical failures and electronic failures, characterized in that: The following steps are involved: Step 1: Confirm the expected life of the test product; Step 2: Determine the total sample size of the test product; Step 3, determine the failure rate function of each electronic device in the test product over time; Step 4, determine the failure rate function of each mechanical structural component in the test product over time; Step 5, calculating the time axis integral of the failure rate distribution of each electronic component with the expected life of the test equipment as the cut-off time, and obtaining the sample weight factor of each electronic component; Step 6, calculating the time axis integral of the failure rate distribution of each mechanical structural component with the expected life of the test equipment as the cut-off time, and obtaining the sample weight factor of each mechanical structural component; Step 7: Sum the sample weight factors of each electronic device and the sample weight factors of each mechanical structure to obtain a total sample weight factor; Step 8, calculate the proportion of the sample factors of each electronic device and each mechanical structure part to the total sample weight factor, and obtain the distribution coefficient of each sample; Step 9: Calculate the product of each sample allocation coefficient and the total sample size, round the result to the nearest integer, and obtain the sample allocation amount of each electronic component and each mechanical structural part.

2. The method for allocating maintainability test samples considering both mechanical failure and electronic failure according to claim 1, characterized in that: The expected life of the confirmatory test product described in step 1 is as follows: Confirm the expected life of the product based on the product contract or product life estimate.

3. The method for allocating maintainability test samples considering both mechanical failure and electronic failure according to claim 1, characterized in that: Determine the total sample size of the test product as described in step 2 as follows: According to the actual situation of the test product itself and Table A1 in GJB 2072-1994 "Maintainability Test and Evaluation Standard", obtain the total sample size information of the test product.

4. The method for allocating maintainability test samples considering both mechanical failure and electronic failure according to claim 1, characterized in that: The failure rate function of each electronic component in the test product over time as described in step 3 is as follows: The life of electronic devices follows an exponential distribution. The failure rate of each electronic device in the test product is a constant and does not change with the use time. Therefore, the failure rate function λ of the i-th electronic device is i ′(t) is: λ i ′(t)=D i Where, t represents working time; D i is a constant, representing the failure rate of the ith electronic component; the failure rate of each electronic component is determined according to GJB / Z 299C-2006 “Handbook of Reliability Prediction of Electronic Equipment”.

5. The method for allocating maintainability test samples taking into account both mechanical failures and electronic failures according to any one of claims 1 to 4, characterized in that: The failure rate function of each mechanical structural component in the test product over time as described in step 4 is as follows: The life of mechanical components follows the Weibull distribution. The failure rate of each mechanical component in the test product changes with the use time. Therefore, the failure rate function λ of the i-th mechanical component is i ″(t) is: Wherein, t represents the working time; m is the shape parameter of the Weibull distribution; η is the location parameter of the Weibull distribution; the Weibull distribution parameters are determined and estimated through a large number of experiments, observation data or component failure database information.

6. The method for allocating maintainability test samples considering both mechanical failure and electronic failure according to claim 5, characterized in that: The calculation described in step 5 integrates the failure rate distribution time axis of each electronic component with the expected life of the test equipment as the cut-off time to obtain the sample weight factor of each electronic component, which is as follows: Among them, a i ′ represents the sample weight factor of the i-th electronic device; T represents the product life; λ i ′(t) represents the failure rate function of the i-th electronic device; t represents the working time.

7. The method for allocating maintainability test samples considering both mechanical failure and electronic failure according to claim 6, characterized in that: The calculation described in step 6 integrates the failure rate distribution time axis of each mechanical structural component with the expected life of the test equipment as the end time to obtain the sample weight factor of each mechanical structural component, which is as follows: Among them, a i ″ represents the sample weight factor of the i-th mechanical structure; T represents the product life; λ i ″(t) represents the failure rate function of the i-th mechanical structure component; t represents the working time.

8. The method for allocating maintainability test samples considering both mechanical failure and electronic failure according to claim 7, characterized in that: The sample weight factors of each electronic device and the sample weight factors of each mechanical structure are summed up in step 7 to obtain the total sample weight factor, which is as follows: Where c represents the total sample weight factor; p′ represents the number of electronic devices; a i ′ represents the sample weight factor of the i-th electronic device; p″ represents the number of mechanical structural parts; a i ″ represents the sample weight factor of the i-th mechanical structure component.

9. The method for allocating maintainability test samples considering both mechanical failure and electronic failure according to claim 8, characterized in that: Step 8 calculates the ratio of sample factors of each electronic device and each mechanical structure part to the total sample weight factor, and obtains the distribution coefficient of each sample, which is as follows: Among them, e i ′ represents the sample distribution coefficient of the i-th electronic device; e i ″ represents the sample distribution coefficient of the i-th mechanical structure component.

10. The method for allocating maintainability test samples considering both mechanical failure and electronic failure according to claim 9, characterized in that: The product of the sample allocation coefficient and the total sample size is calculated in step 9, and the result is rounded off to the nearest integer to obtain the sample allocation amount of each electronic device and each mechanical structure part, as follows: g i ′=e i ′×N g i ″=e i ″×N Among them, g i ′ represents the sample allocation of the i-th electronic device; e i ′ represents the sample distribution coefficient of the i-th electronic device; N represents the total sample size; g i ″ represents the sample distribution amount of the i-th mechanical structure component; e i ″ represents the sample distribution coefficient of the i-th mechanical structure component.

Images