CN113806218B - Fault comprehensive logic judgment optimization method - Google Patents

Abstract

The invention discloses a fault comprehensive logic judgment optimization method, which comprises the steps of setting different weighting coefficients for each fault information according to different alarm types caused by faults, and summing the fault weighting processes; and then determining a final fault alarm according to the fault weighted sum. The method converts the logic judgment into the numerical judgment, and is simple and efficient; the condition of logic judgment is greatly reduced, branch sentences are reduced, and the code reliability is improved; the code is simplified, and the safety is improved.

Description

Fault comprehensive logic judgment optimization method

Technical Field

The invention belongs to the technical field of aircraft brake, and particularly relates to a fault judgment optimization method.

Background

To improve the reliability of electronic devices, more and more detection techniques are applied in the design, thereby generating more and more fault information. The basic fault information is comprehensively judged to form higher-level comprehensive fault information, the higher-level comprehensive fault information is uploaded to an electromechanical management computer, and finally, a pilot is prompted to make corresponding processing in an alarm mode.

Taking an airplane brake control unit as an example, the system detects accessories such as an instruction sensor, a servo valve, a cut-off valve and the like, a pressure loop and a power supply, and generates fault information which is to be synthesized into a fault alarm mode such as a brake channel fault, a positive/negative driving failure, half brake loss, brake failure and the like. For multi-wheel systems, the number of accessories and channels is numerous, the number of fault information is tens, and the number of basic fault combination logics corresponding to the same alarm is thousands. The traditional fault comprehensive logic adopts condition judgment sentences, the judgment conditions in each judgment sentence are up to dozens, and the judgment branches are also up to dozens. Such a code structure is too cumbersome and complex, which is detrimental to efficient execution and security of the code, and also increases the workload of software testing.

The patent CN104699067A 'a comprehensive system fault declaration processing method' proposes to use a state matrix mode to process the faults of the fly-by-wire control system. The method only declares the fault information of each subsystem according to a unified format for processing, and does not relate to a judging method for synthesizing basic fault information into higher-level fault information according to certain logic.

Disclosure of Invention

In order to overcome the defects of the prior art and inconvenient software implementation, the invention provides a fault comprehensive logic judgment optimization method, which sets different weighting coefficients for each fault information according to different alarm types caused by faults, and sums the fault weighted processing; and then determining a final fault alarm according to the fault weighted sum. The method converts the logic judgment into the numerical judgment, and is simple and efficient; the condition of logic judgment is greatly reduced, branch sentences are reduced, and the code reliability is improved; the code is simplified, and the safety is improved.

The technical scheme adopted by the invention for solving the technical problems comprises the following steps:

step 1: designing a fault comprehensive logic table;

listing logic combinations of all basic faults according to an alarm mode to complete a fault comprehensive logic table; assuming that there are 1 a fault, 1 b fault and n c faults in the aircraft control system, and these faults are integrated into three alarm modes, namely alarm mode 1, alarm mode 2 and alarm mode 3, the fault integrated logic table is shown in table 1:

table 1 fault synthesis logic table

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In the table- -representing any significant value;

step 2: determining a weighting coefficient;

determining a weighting coefficient according to the relation between the number of basic faults and the comprehensive faults; as shown in table 1, one fault a or one fault b and n faults c are integrated into an alarm mode 2, so that the fault level of the fault a and the fault b is higher than that of the fault c, the weighting coefficient of the fault a and the fault b is set to be 2n, and the weighting coefficient of the fault c is set to be 1;

step 3: the weighted summation synthesizes faults;

judging a fault comprehensive result according to the weighted sum of the faults in the table 1 to obtain a table 2:

table 2 fault weighted summation

From table 2, the final fault comprehensive result can be obtained by judging the numerical relation of the final weighted result; when the fault weighted sum is smaller than n, the alarm mode 1 is the alarm mode 2 when the fault weighted sum is larger than or equal to n and smaller than 4n, and the alarm mode 3 when the fault weighted sum is larger than or equal to 4 n.

The beneficial effects of the invention are as follows:

the invention carries out weighting treatment according to the influence caused by the fault; the logic judgment is converted into the numerical judgment, so that the method is simpler and more efficient; the logic judgment conditions are greatly reduced, branch sentences are reduced, the circle complexity of software design is remarkably reduced, and the testability and the safety of the software are greatly improved.

Drawings

FIG. 1 is a diagram showing steps for implementing the weighted sum determination method of the present invention.

FIG. 2 is a software flow chart comparing a conventional judging method with the weighted sum judging method of the present invention. Wherein (a) is a flow chart of a traditional judging method and (b) is a flow chart of a method of the invention.

FIG. 3 is a comparison of software code testing for a conventional judgment method and a weighted sum judgment method of the present invention. Wherein (1) the traditional judging method software code test result and (b) the method software code test result.

Detailed Description

The invention will be further described with reference to the drawings and examples.

In order to overcome the defects of the traditional fault comprehensive treatment, the invention provides a comprehensive mode of fault weighted summation. According to the method, different weighting coefficients are set for each piece of fault information according to different alarm types caused by faults, and then the fault weighting processing is carried out and then the sum is carried out. And judging a final fault alarm mode according to the fault weighted sum.

As shown in fig. 1, a fault comprehensive logic judgment optimization method includes the following steps:

step 1: designing a fault comprehensive logic table;

listing logic combinations of all basic faults according to an alarm mode to complete a fault comprehensive logic table; assuming that there are 1 a fault, 1 b fault and n c faults in the aircraft control system, and these faults are integrated into three alarm modes, namely alarm mode 1, alarm mode 2 and alarm mode 3, the fault integrated logic table is shown in table 1:

table 1 fault synthesis logic table

In the table- -representing any significant value;

step 2: determining a weighting coefficient;

determining a weighting coefficient according to the relation between the number of basic faults and the comprehensive faults; as shown in table 1, one fault a or one fault b and n faults c are integrated into an alarm mode 2, so that the fault level of the fault a and the fault b is higher than that of the fault c, the weighting coefficient of the fault a and the fault b is set to be 2n, and the weighting coefficient of the fault c is set to be 1;

step 3: the weighted summation synthesizes faults;

judging a fault comprehensive result according to the weighted sum of the faults in the table 1 to obtain a table 2:

table 2 fault weighted summation

From table 2, the final fault comprehensive result can be obtained by judging the numerical relation of the final weighted result; when the fault weighted sum is smaller than n, the alarm mode 1 is the alarm mode 2 when the fault weighted sum is larger than or equal to n and smaller than 4n, and the alarm mode 3 when the fault weighted sum is larger than or equal to 4 n.

Specific examples:

the following describes in detail the implementation of the steps in connection with the integrated logic of half brake loss and complete brake failure of a 12-wheel aircraft brake system.

1. Designing a fault comprehensive logic table;

the number of the wheels in the 12-wheel aircraft braking system is one, and the number of the wheels is three. The two inner side wheels of each row of 4 wheels are one braking channel, and the two outer side wheels are one braking channel, so that the inner side and the outer side are respectively provided with 3 braking channels. The brake control system is used for independently controlling the inner machine wheel and the outer machine wheel and is divided into an inner plate and an outer plate. The failure synthesis logic for losing half of the brake and complete failure of the brake is shown in Table 3

Table 3 fault information and comprehensive logic for brake control system of 12-wheel aircraft

2. Determining weighting coefficients

Because the inner plate and the outer plate can respectively cause half brake failure, the total of the failure can cause brake failure, the failure of the inner plate and the outer plate is calculated separately to determine half brake failure, and then the total of the inner plate and the outer plate failure is calculated to judge whether the brake failure is formed or not. The failure of the single board power supply and the failure of the controller of the single board can cause half of the brake alarm to be lost, and the failure of three channels can also cause half of the brake alarm to be lost. Therefore, the weighting coefficients of the power failures of the inner and outer plates and the failures of the inner and outer plate controllers are set to 3, and the weighting coefficients of the other failures are set to 1.

3. Weighted summation and fault synthesis;

and respectively calculating the fault weighted sum of the inner plate and the outer plate. Since the biggest impact that a single side plate can cause is the loss of half the brakes, the respective failure weights of the inner and outer plates should be set to upper clipping of 3. Then the weighted failure sum of the inner plate and the outer plate is summed, if the failure combination is more than 3, the brake fails; if the sum of the faults is equal to 3, half of the brake is lost. Therefore, the number of the judging sentences which are needed to be approximately 10 is reduced to 3, the complicated judging conditions in each judging sentence are reduced to single numerical value judgment, and the software is simple and clear to realize.

Table 4 fault weighted summation for a 12 wheel aircraft brake control system

The invention provides a comprehensive judgment mode of fault weighted summation. According to the method, different weighting coefficients are set for each piece of fault information according to different alarm types caused by faults, and then the fault weighting processing is carried out and then the sum is carried out. And judging the final fault alarm according to the fault weighted sum. Converting complex logic judgment into simple numerical judgment; the condition of logic judgment is greatly reduced, branch sentences are reduced, and code testability is improved; the code is simplified, and the safety is improved.

As shown in fig. 2 and 3, the above examples were designed into a software flow chart and a software code according to the conventional condition judgment and the weighted sum judgment method of the present invention, respectively. From the flow chart, it can be seen that the weighted sum judging method is significantly simpler than the conventional method. The software code is tested using an LDRA specialized software testing tool. The complexity of the software loop required by the general military software is less than 10, the complexity of the software loop designed by adopting the traditional condition judgment method is 12, the requirement is not met, and the test is failed. The complexity of the software loop designed by the judging method is reduced from original 12 to 4, and the software loop passes the test. Meanwhile, maintainability and testability of the software are respectively improved from 75% and 88% to 100%, so that the quality of the software is remarkably improved.

Claims (1)

1. The fault comprehensive logic judgment optimization method is characterized by comprising the following steps of:

step 1: designing a fault comprehensive logic table;

listing logic combinations of all basic faults according to an alarm mode to complete a fault comprehensive logic table; assuming that there are 1 a fault, 1 b fault and n c faults in the aircraft control system, and these faults are integrated into three alarm modes, namely alarm mode 1, alarm mode 2 and alarm mode 3, the fault integrated logic table is shown in table 1:

table 1 fault synthesis logic table

In the table- -representing any significant value;

step 2: determining a weighting coefficient;

determining a weighting coefficient according to the relation between the number of basic faults and the comprehensive faults; as shown in table 1, one fault a or one fault b and n faults c are integrated into an alarm mode 2, so that the fault level of the fault a and the fault b is higher than that of the fault c, the weighting coefficient of the fault a and the fault b is set to be 2n, and the weighting coefficient of the fault c is set to be 1;

step 3: the weighted summation synthesizes faults;

judging a fault comprehensive result according to the weighted sum of the faults in the table 1 to obtain a table 2:

table 2 fault weighted summation

From table 2, the final fault comprehensive result can be obtained by judging the numerical relation of the final weighted result; when the fault weighted sum is smaller than n, the alarm mode 1 is the alarm mode 2 when the fault weighted sum is larger than or equal to n and smaller than 4n, and the alarm mode 3 when the fault weighted sum is larger than or equal to 4 n.

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