CN104965939B - A kind of hoop truss formula deployable antenna analysis method for reliability - Google Patents

Abstract

The present invention relates to hoop truss formula deployable antenna analysis method for reliability field, in particular to a kind of hoop truss formula deployable antenna analysis method for reliability based on section and probability.This method considers random uncertain parameter present in hoop truss formula deployable antenna and section uncertain parameter simultaneously, avoid some unnecessary hypothesis, calculated result is set to be more in line with actual conditions, and it is predicted to provide a reasonable data reference range instead of monodrome Predicting Reliability for the safety Design of deployable antenna with interval reliability.The reliability of this method raising system.

Description

A Reliability Analysis Method for a Peripheral Truss-Type Deployable Antenna

technical field

The invention relates to the field of reliability analysis methods for peripheral truss-type deployable antennas, in particular to a reliability analysis method for peripheral-truss-type deployable antennas based on interval and probability.

Background technique

With the exploration of space by human beings, various spaceborne antennas have come out one after another. Spaceborne antennas are launched into space by a launch vehicle. Due to the limitation of the size of the launch vehicle, large spaceborne antennas are generally in an expandable form, that is, they are folded during the launch phase, and will be expanded after they are launched into space. Therefore, the success of the satellite antenna launch mission depends to a large extent on whether the deployable antenna can be successfully deployed and locked, and then maintained in a working state. Obviously, if the satellite-borne deployable antenna cannot be deployed smoothly, the huge manpower, material resources, and financial resources paid for the entire satellite launch will be destroyed. Therefore, it is necessary to analyze its reliability in the design stage to improve the satellite. The deployment reliability of the on-board deployable antenna.

There are many uncertain events in the deployment process of the spaceborne deployable antenna, such as the breakage of the power cable, the stuck gear, the stuck rotating joint, etc. At present, the reliability analysis of the spaceborne deployable antenna is to take all the influences of the deployable antenna into consideration. The parameters of each uncertain event in the system are regarded as random parameters, and the traditional probability method is used for analysis.

In fact, among the factors that affect the failure of these uncertain events, some parameters obey a certain probability distribution and are random parameters, while other parameters cannot give their accurate probability distribution, only an interval can be given. These parameters act as interval parameters. At this time, the analysis using the method of probabilistic reliability has a large assumption, which will lead to large errors or even errors in the calculated results. Therefore, it is necessary to consider the influence of random parameters and interval parameters at the same time, and adopt the mixed reliability of interval and probability. analytical methods to conduct research.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose a reliability analysis method of the surrounding truss-type deployable antenna based on interval and probability, so that the random uncertain parameters and interval uncertain parameters existing in the surrounding truss-type deployable antenna can be considered at the same time, so as to avoid the problem of Some unnecessary assumptions make the calculated results more in line with the actual situation and improve the reliability of the system.

The technical solution of the present invention is realized by the following steps: a reliability analysis method for a peripheral truss-type deployable antenna, which at least includes the following steps:

1) Taking the antenna deployment failure as the top event, the fault tree modeling of the surrounding truss-type deployable antenna is carried out, and the factors affecting the deployment failure of the surrounding truss deployable antenna are classified as follows;

2) Classify the bottom events of the established peripheral truss deployable antenna failure tree model according to the failure probability;

a. Events for which failure probability is obtained through database evaluation;

b. Events for which failure probability is obtained through experiments;

c. Events for which failure probability is obtained by computational analysis.

3) The bottom event obtained after unfolding the events a and b in step 2) obtains the corresponding failure probability interval of the bottom event by means of database evaluation or experiment;

4) Carry out a reliability analysis on the bottom event obtained after unfolding the event c in step 2), find out the uncertain factors that lead to the failure of the bottom event, and establish the limit state function g for these uncertain variables according to the failure criterion of the bottom event ;

5) Classify the uncertain factors of the bottom event in step 4), and regard the factors that can give probability distribution as random variables X, but cannot obtain the probability distribution, but can give the factors whose variation interval can be regarded as the interval variable y;

6) Convert the variables X and Y in step 5) into standardized variables u and v, and the conversion process of u and v is: u=(X-μ _X )/σ _X , v=(YY ^m )/Y ^r , the limit state function function is transformed into G(u,v), and the interval and probability mixed reliability model for this type of event is established by using the interval and probability mixed reliability method:

7) Solve the two mixed reliability models in step 6) through the optimization method, and obtain the failure probability interval of this type of event

8) Using the failure tree analysis method and the method of interval mathematics, the obtained failure probability interval of the bottom event is calculated up layer by layer, and finally the failure probability interval of the top event is obtained.

In the step 1, the factors affecting the deployment failure of the surrounding truss deployable antenna are classified as follows:

a. Unlocking fails;

b. The mesh surface unfolding fails;

c. The expansion failure of the surrounding truss;

d. Limit failure;

The above events are carried out one by one, and the failure factors are given;

Whether the event cannot or is not necessary to continue; No, continue; Yes, the obtained event is called the bottom event;

Connect all levels of events with OR gates to obtain the deployed failure tree model of the surrounding truss-type deployable antenna;

Beneficial effects of the present invention: the present invention simultaneously considers the random uncertain parameters and interval uncertain parameters existing in the surrounding truss-type deployable antenna, avoids some unnecessary assumptions, makes the calculated results more in line with the actual situation, and uses The interval reliability prediction replaces the single value reliability prediction, which provides a reasonable data reference range for the safety design of the deployable antenna.

Description of drawings

Fig. 1 is the specific implementation flow chart of the present invention;

Figure 2 is a diagram of an example of modeling.

Description of symbols involved in the formula in the present invention:

u: random variable after standardization; ν: interval variable after standardization; β : lower limit of reliability index; upper limit of reliability index; μ _X : mean value of random variable X; σ _X : mean square error of random variable X; Y ^m : mean value of interval variable Y; Y ^r : dispersion of interval variable Y; P : lower limit of failure probability; The upper limit of the probability of failure.

Detailed ways

As shown in Figure 1, the steps of a reliability analysis method for a surrounding truss-type deployable antenna are as follows: 1) Carry out a failure analysis on the surrounding truss-type deployable antenna, take the antenna deployment failure as the top event P, and analyze the surrounding truss-type deployable antenna. The antenna is modeled as a fault tree, and the factors that affect the deployment failure of the surrounding truss deployable antenna are classified:

a. Unlock failure E;

b. The mesh surface unfolds the failure F;

c. The expansion failure G of the surrounding truss;

d. Limit failure H;

The above events are carried out one by one, and the failure factors are given;

Whether the event cannot or is not necessary to continue to unfold; No, continue; Yes, the obtained event is called the bottom event, such as electronic ignition failure, synchronous gear stuck, pull rope broken, etc.;

As shown in Figure 2, the events at all levels are connected with OR gates to obtain the deployed failure tree model of the surrounding truss-type deployable antenna;

2) Classify the bottom events of the peripheral truss deployable antenna failure tree model shown in Figure 2 according to the failure probability:

a. Events E1, E2, E3, etc. to obtain failure probability through database evaluation;

b. Event G1 for obtaining failure probability through experiments;

c. Events G221, G222, G223, etc. with failure probability obtained through analysis and calculation.

3) For E1, E2, E3, G1 and other bottom events, the corresponding failure probability interval of the event can be obtained by evaluating or doing experiments.

4) Carry out reliability analysis for G221, G222, G223 and other bottom events, find out the uncertain factors that lead to the failure of such bottom events, and establish the limit state function g of these uncertain variables according to the failure criterion of the event.

5) Classify the uncertain factors of each event in step 4). Taking the G223 event as an example, the deflection angles of the gear axis θ ₁ , θ ₂ and the center distance a of the two gears are regarded as random variables X=(θ ₁ , θ ₂ , a), the tooth tip circle diameter d _a of the gear and the tooth root circle diameter d _f of the gear are regarded as interval variables Y=(d _a , d _f ).

6) Convert X and Y in step 5) into standardized variables u and v, and the conversion process of u and v is: u=(X-μ _X )/σ _X , v=(YY ^m )/Y ^r , the limit state function function is transformed into G(u,v), and the interval and probability mixed reliability model of the G223 event is established by using the interval and probability mixed reliability method:

7) The failure probability interval of the G223 event can be obtained by solving the two mixed reliability models in step 6) by the optimization method

In the same way, using step 5) to step 7), the failure probability interval of other bottom events can be obtained;

8) Using the failure tree analysis method and interval mathematics method, the obtained bottom event failure probability interval is calculated up layer by layer, and finally the failure probability interval of the top event P can be obtained. The bottom events are independent of each other, the calculation process is as follows:

where pi is the lower limit of the failure probability of the _ith bottom event, where,

The calculation process is similar to p (E);

Similarly, the upper limit of the probability of failure is:

1) Taking the deployment failure of the antenna as the top event, the fault tree modeling of the surrounding truss-type deployable antenna is carried out;

The factors affecting the deployment failure of the surrounding truss deployable antenna are classified as follows;

a. Unlocking fails;

b. The mesh surface unfolding fails;

c. The expansion failure of the surrounding truss;

d. Limit failure;

The above events are carried out one by one, and the failure factors are given;

Whether the event cannot or is not necessary to continue; No, continue; Yes, the obtained event is called the bottom event;

Connect all levels of events with OR gates to obtain the deployed failure tree model of the surrounding truss-type deployable antenna;

2) Classify the bottom events of the established peripheral truss deployable antenna failure tree model according to the failure probability;

a. Events for which failure probability is obtained through database evaluation;

b. Events for which failure probability is obtained through experiments;

c. Events for which failure probability is obtained by computational analysis.

Claims (1)

1. A reliability analysis method for a peripheral truss type deployable antenna is characterized by comprising the following steps: at least comprises the following steps:

1) taking the antenna expansion failure as a top event, and performing fault tree modeling on the peripheral truss type expandable antenna;

2) classifying bottom events of the established peripheral truss type expandable antenna failure tree model according to failure probability;

a. evaluating an event for obtaining failure probability through a database;

b. obtaining the event of failure probability through experiments;

c. obtaining the event of failure probability through analysis and calculation;

3) obtaining a failure probability interval corresponding to the bottom event by a database evaluation or experimental method for the bottom event obtained after the events a and b in the step 2) are expanded;

4) performing reliability analysis on the bottom event obtained after the event c in the step 2) is unfolded, finding out uncertain factors causing failure of the bottom event, and establishing a limit state function g related to the uncertain variables according to a failure criterion of the bottom event;

5) classifying uncertain factors in the bottom event in the step 4), regarding the factors capable of giving probability distribution as random variables X, not obtaining probability distribution, and giving the factors of a change interval as interval variables Y;

6) the transformation process of the variables X and Y in the step 5) into the standardized variables u and v, u and v is as follows: u ═ X- μ_X)/σ_X，v＝(Y-Y^m)/Y^rAnd converting the extreme state function into G (u, v), and establishing an interval and probability mixed reliability model about the bottom event by using an interval and probability mixed reliability method:

wherein, u: random variables after normalization; v: interval variables after normalization;β: lower limit of reliability index;an upper limit of a reliability index; mu.s_X: the mean of the random variable X; sigma_X: the mean square error of the random variable X; y is^m: the mean value of the interval variable Y; y is^r: dispersion of interval variable Y;

7) solving the two mixed reliability models in the step 6) by an optimization method to obtain a failure probability interval of a bottom event

Wherein,P: a lower limit of failure probability;an upper failure probability limit;

8) calculating the failure probability interval of the obtained bottom event layer by layer upwards by using a failure tree analysis method and an interval mathematic method to finally obtain the failure probability interval of the top event;

the fault tree modeling of the peripheral truss type deployable antenna in the step 1) comprises the following steps;

classifying factors influencing the unfolding failure of the deployable antenna of the peripheral truss into the following classes;

a. unlocking failure;

b. the expansion of the mesh surface is failed;

c. unfolding the peripheral truss to fail;

d. limiting is invalid;

respectively expanding the events a, b, c and d class by class to give failure factors;

whether the event cannot or is not necessary to continue deployment; if not, continuing; the obtained event is called a bottom event;

and connecting all levels of events by using an OR gate to obtain an expansion failure tree model of the peripheral truss type expandable antenna.