阅读说明：本技术 二维流量表的反插方法 (Reverse insertion method of two-dimensional flow meter ) 是由 李志鹏 郭潇晟 邢林 李辉 于 2020-12-15 设计创作，主要内容包括：本发明公开了一种二维流量表的反插方法,具体步骤包括：步骤100：将二维流量表中的每个转速值下最大的燃油流量值对应的油针位置提取出,并将提出的油针位置与对应的转速值重新组成的一个一维的转速-油针位置表。步骤200：根据给定转速值及给定燃油流量及二维流量表计算出第一油针位置插值。步骤300：根据给定转速值及转速-油针位置表计算出第二油针位置插值,从第一油针位置插值和第二油针位置插值中选择较小的值作为输出油针位置。根据上述技术方案的二维流量表的反插方法,可以有效限制油针位置的输出,避免燃油流量进入再退出饱和区时,油针位置无法及时降低,导致燃油流量未及时降低造成发动机超温。(The invention discloses a reverse insertion method of a two-dimensional flow meter, which comprises the following specific steps: step 100: and extracting the position of the oil needle corresponding to the maximum fuel flow value under each rotating speed value in the two-dimensional flow meter, and recombining the extracted position of the oil needle and the corresponding rotating speed value to form a one-dimensional rotating speed-oil needle position meter. Step 200: and calculating the first oil needle position interpolation value according to the given rotating speed value, the given fuel flow and the two-dimensional flow meter. Step 300: and calculating a second oil needle position interpolation value according to the given rotating speed value and the rotating speed-oil needle position table, and selecting a smaller value from the first oil needle position interpolation value and the second oil needle position interpolation value as an output oil needle position. According to the reverse insertion method of the two-dimensional flow meter, the output of the position of the oil needle can be effectively limited, and the problem that the engine overtemperature is caused because the position of the oil needle cannot be timely reduced when the fuel flow enters and exits a saturation region is avoided.)

1. A reverse insertion method of a two-dimensional flow meter is characterized by comprising the following steps:

step 100: extracting the oil needle position corresponding to the maximum fuel oil flow value under each rotating speed value in the two-dimensional flow meter, and recombining the extracted oil needle position and the corresponding rotating speed value to form a one-dimensional rotating speed-oil needle position meter;

step 200: calculating a first oil needle position interpolation value according to a given rotating speed value, a given fuel flow and a two-dimensional flow meter;

step 300: and calculating a second oil needle position interpolation value according to the given rotating speed value and the rotating speed-oil needle position table, and selecting a smaller value from the first oil needle position interpolation value and the second oil needle position interpolation value as an output oil needle position.

2. The method of claim 1, wherein said step 200 comprises:

step 210: selecting a first rotating speed value and a second rotating speed value which have the closest values from a two-dimensional flow meter according to a given rotating speed value;

step 220: determining a straight line by using the first rotating speed value and the corresponding first fuel flow value and the corresponding second rotating speed value under the same oil needle position and calculating the corresponding fuel flow value of the given rotating speed value on the straight line and recording as fuel flow interpolation;

step 230: repeating the step 220 until all fuel flow interpolation values corresponding to the oil needle positions are calculated, and combining the oil needle positions and the fuel flow interpolation values corresponding to the oil needle positions into a one-dimensional fuel flow-oil needle position table;

step 240: and calculating a first oil needle position interpolation value according to the given fuel flow value and the fuel flow-oil needle position table.

3. The reverse interpolation method for the two-dimensional flow meter according to claim 1, wherein in step 100, if there are a plurality of the same maximum fuel values at a certain rotation speed, the minimum needle position corresponding to the plurality of the maximum fuel values is taken as the corresponding needle position of the rotation speed, and recorded in the rotation speed-needle position table.

4. The method of claim 2, wherein in step 220, if the given speed value is not within the threshold range with the first and second speed values as endpoints, the fuel flow value is interpolated to the fuel flow value at the endpoint closest to the given speed value.

5. The method of claim 1, wherein the rotational speed value in the two-dimensional flow meter is strictly monotonically increasing.

6. The reverse interpolation method of a two-dimensional flow meter according to claim 1, wherein the position value of the oil needle in the two-dimensional flow meter is strictly monotonically increased.

7. The method of claim 1, wherein the fuel flow values in each row and each column of the two-dimensional flow meter are monotonically increasing.

Technical Field

The invention relates to the field of control of aero-engines, in particular to a reverse insertion method of a two-dimensional flow meter.

Background

In the fuel control of an aircraft engine, Full Authority Digital Engine Control (FADEC) software usually calculates required fuel setting firstly, then calculates a required oil needle position value by combining a fuel flow two-dimensional meter and current rotating speed reverse interpolation, and then controls a motor to change the position of a metering valve oil needle according to the oil needle position value, so that the fuel flow transmitted to an engine combustion chamber is changed.

The fuel flow meter is usually a two-dimensional meter with the rotation speed and the position of the oil needle as horizontal and vertical coordinates and the fuel flow as the value in the meter. However, the fuel flow rate shows a non-strict increasing relation of increasing first and then keeping unchanged for the same rotating speed point along with the increase of the position of the oil needle.

In the existing reverse interpolation method, if the fuel flow value falls into a non-strict monotonous region (saturated region), a one-to-many condition violating the interpolation constraint occurs, at the moment, the traditional interpolation algorithm is output according to the maximum oil needle position, when the fuel flow value exits from the saturated region, the output oil needle position jumps in a step mode, the oil needle feedback needs to be followed for a certain time, and the phenomenon of engine overtemperature is caused because the oil is not reduced in time.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a method for reversely inserting the position of an oil needle of a two-dimensional flow meter, which can effectively avoid the overtemperature of an engine.

The technical scheme is as follows: the reverse insertion method of the two-dimensional flow meter specifically comprises the following steps:

step 100: extracting the oil needle position corresponding to the maximum fuel oil flow value under each rotating speed value in the two-dimensional flow meter, and recombining the extracted oil needle position and the corresponding rotating speed value to form a one-dimensional rotating speed-oil needle position meter;

step 200: calculating a first oil needle position interpolation value according to a given rotating speed value, a given fuel flow and a two-dimensional flow meter;

step 300: and calculating a second oil needle position interpolation value according to the given rotating speed value and the rotating speed-oil needle position table, and selecting a smaller value from the first oil needle position interpolation value and the second oil needle position interpolation value as an output oil needle position.

Further, the step 200 includes:

step 210: selecting a first rotating speed value and a second rotating speed value which have the closest values from a two-dimensional flow meter according to a given rotating speed value;

step 220: determining a straight line by using the first rotating speed value and the corresponding first fuel flow value and the corresponding second rotating speed value under the same oil needle position and calculating the corresponding fuel flow value of the given rotating speed value on the straight line and recording as fuel flow interpolation;

step 230: repeating the step 220 until all fuel flow interpolation values corresponding to the oil needle positions are calculated, and combining the oil needle positions and the fuel flow interpolation values corresponding to the oil needle positions into a one-dimensional fuel flow-oil needle position table;

step 240: and calculating a first oil needle position interpolation value according to the given fuel flow value and the fuel flow-oil needle position table.

Further, in step 100, if there are multiple same maximum fuel values at a certain rotation speed value, the minimum needle position corresponding to the multiple maximum fuel values is taken as the corresponding needle position of the rotation speed value, and is recorded in the rotation speed-needle position table.

Further, in step 220, if the given rotation speed value is not within the threshold range with the first rotation speed value and the second rotation speed value as the endpoints, the fuel flow value at the endpoint closest to the given rotation speed value is interpolated from the fuel flow values.

Further, the rotating speed value in the two-dimensional flow meter is monotonically increased.

Further, the position value of the oil needle in the two-dimensional flow meter is monotonically increased.

Has the advantages that: compared with the prior art, the invention has the following advantages: the oil needle position can be effectively prevented from entering a saturation area, the over-temperature and other parameter over-limit risk of the engine is reduced, and the service life of the engine is prolonged.

Drawings

FIG. 1 is a schematic flow chart of a first embodiment of the present invention;

FIG. 2 is a schematic flow chart of a second embodiment of the present invention;

FIG. 3 is an extracted schematic diagram of the speed-needle position table of the present invention.

Detailed Description

The technical scheme of the invention is further explained by combining the attached drawings.

Referring to fig. 1, the reverse insertion method of the two-dimensional flow meter according to the embodiment of the present invention specifically includes the following steps:

step 100: extracting the oil needle position corresponding to the maximum fuel oil flow value under each rotating speed value in the two-dimensional flow meter, and recombining the extracted oil needle position and the corresponding rotating speed value to form a one-dimensional rotating speed-oil needle position meter;

step 200: calculating a first oil needle position interpolation value according to a given rotating speed value, a given fuel flow and a two-dimensional flow meter;

step 300: and calculating a second oil needle position interpolation value according to the given rotating speed value and the rotating speed-oil needle position table, and selecting a smaller value from the first oil needle position interpolation value and the second oil needle position interpolation value as an output oil needle position.

According to the reverse insertion method of the two-dimensional flow meter in the technical scheme, when the fuel flow enters a saturation area, the same fuel flow corresponds to a plurality of oil needle positions, at the moment, the first oil needle position interpolation calculated through the reverse interpolation of the two-dimensional flow meter and the second oil needle position interpolation calculated through the screened one-dimensional rotating speed-oil needle position meter reverse difference are compared, and the smaller value is selected as the output oil needle position, so that the problems that the oil needle position cannot jump in time in a step jump manner when the fuel flow is ensured, the oil needle position cannot jump out of the saturation area due to overhigh oil needle position, the engine overtemperature or parameter overrun and the like due to untimely oil reduction are avoided, and the service life of the engine is prevented from being greatly prolonged.

Referring to fig. 3, in some embodiments, if there are multiple same maximum fuel flow values at a certain speed value, the corresponding minimum fuel needle position value of the fuel flow values is selected and recorded in the one-dimensional speed-fuel needle position table as the fuel needle position value corresponding to the speed value in the table in step 100. In some embodiments, in order to facilitate finding the maximum value and the minimum value, the rotation speed value and the oil needle position value in the two-dimensional flow meter can be set in a strictly monotonically increasing manner, and the fuel flow values in each row and each column can also be set in a monotonically increasing order. If only one maximum fuel flow value exists at a certain rotating speed value, the position value of the last row of oil needles is the corresponding value of the rotating speed value in a rotating speed-oil needle position table; if a plurality of maximum fuel flow values exist at a certain rotating speed value, the oil needle position value of the uppermost row in the rows with the maximum fuel flow is the corresponding value of the rotating speed value in the rotating speed-oil needle position table.

Referring to FIG. 2, in some embodiments, the process of calculating the first needle position interpolation by reverse interpolation from the two-dimensional flow meter and the given speed value and the given fuel flow value includes the steps of:

step 210: selecting a first rotating speed value and a second rotating speed value which have the closest values from a two-dimensional flow meter according to a given rotating speed value;

step 220: determining a straight line by using the first rotating speed value and the corresponding first fuel flow value and the corresponding second rotating speed value under the same oil needle position and calculating the corresponding fuel flow value of the given rotating speed value on the straight line and recording as fuel flow interpolation;

step 230: repeating the step 220 until all fuel flow interpolation values corresponding to the oil needle positions are calculated, and combining the oil needle positions and the fuel flow interpolation values corresponding to the oil needle positions into a one-dimensional fuel flow-oil needle position table;

step 240: and calculating a first oil needle position interpolation value according to the given fuel flow value and the fuel flow-oil needle position table.

A specific two-dimensional flow meter may be as shown in table 1:

TABLE 1 two-dimensional flow Meter 2dTbl

Wherein y (N) represents the position of the oil needle, X (M) represents the rotating speed, and z (M, N) represents the fuel flow values corresponding to the rotating speeds X (M) and y (N), wherein N and M are natural numbers which are respectively less than or equal to a natural number N and less than or equal to a natural number M.

And recording the given rotating speed value as x and the given fuel flow value as z. Firstly, two rotation speed values which are closest to a given rotation speed value X in a two-dimensional flow meter are found and are recorded as a first rotation speed value X (M1) and a second rotation speed value X (M2), and M1 and M2 are respectively equal to 0,1 and 2 … … M. And determining a straight line by two points determined by the fuel flow values corresponding to X (M1) and X (M2) and X (M1) and X (M2) at the same oil needle position, substituting a given rotating speed value X to calculate a fuel flow interpolation value corresponding to the rotating speed value at the oil needle position, and recording the fuel position value and the fuel flow interpolation value corresponding to the fuel position value into a one-dimensional fuel flow-oil needle position table. Taking the oil needle position y (0) as an example, namely, substituting the given rotating speed value X into a straight line determined by two points of (X (M1), z (M1,0)) and (X (M2), z (M2,0)), and obtaining a fuel flow interpolation z' (0) corresponding to the oil needle position y (0).

And repeating the process until the fuel flow interpolation values corresponding to all the oil needle position values are calculated to form a complete fuel flow-oil needle position table. And then obtaining a first oil needle position interpolation value corresponding to the fuel flow value z from a fuel flow-oil needle position table according to the given fuel flow value z.

It can be understood that the first oil needle position interpolation and the second oil needle position interpolation can be calculated by a linear interpolation method, and can also be calculated by other interpolation methods.

In some embodiments, to further limit the output needle position, in step 220, when the fuel position interpolation is calculated, if the given speed value X is not within the threshold range with X (M1) and X (M2) as endpoints, the fuel flow value corresponding to the speed value closest to the given speed value X is used as the fuel flow interpolation. Taking the needle position y (1) as an example, if the value of X (M1) is closer to the predetermined rotation speed value X, z' (1) is equal to z (M1, 1).