A method for calculating SEP symbols

Abstract

The present invention provides a method for calculating a SEP symbol, comprising: step one: calculating a first unit residual power calculation value SEP1 relative to an axial reference line FRL on a head-up display; step two: converting the calculated first unit residual power calculation value SEP1 into a second unit residual power calculation value SEP2 based on the center of a velocity vector symbol on the head-up display. The present invention calculates the first unit residual power calculation value SEP1 relative to an axial reference line FRL on a head-up display; then converts the first unit residual power calculation value SEP1 into a second unit residual power calculation value SEP2 based on the center of a velocity vector symbol on the head-up display, converts the second unit residual power calculation value SEP2 into a digital signal and transmits it to the head-up display via a bus, so that the position of the SEP symbol can be displayed on the head-up display, thereby solving the problem of unstable display of the SEP symbol, which causes misjudgment by the pilot.

Description

Technical Field

[0001] The invention belongs to aircraft avionics system design technology, and in particular relates to a calculation method of a SEP symbol. Background Art

[0002] The aircraft unit excess energy is also called the aircraft unit excess power, abbreviated as SEP in English, that is, specific excess power. It was proposed by American pilot Boyd, and the formula is SEP = (reasoning - drag) * speed / weight. However, in actual engineering applications, thrust, drag, and weight cannot be directly measured, and the pilot does not need to know the exact SEP value when operating the aircraft. What he needs to know is the change in aircraft energy caused by the aircraft unit excess energy. Therefore, even if the real SEP data is calculated, it cannot be directly applied in engineering.

[0003] At present, there is no SEP symbol display positioning algorithm that is widely used in actual engineering in China. The violent jumping of the SEP symbol on the head-up display seriously affects the pilot's judgment and interpretation of other displayed data. Therefore, it is necessary to independently develop a set of SEP symbol positioning algorithms. Summary of the invention

[0004] In view of the above situation, it is necessary to provide a method for calculating the SEP symbol to address the problems in the prior art.

[0005] A method for calculating a SEP symbol, comprising:

[0006] Step 1: Calculate a first unit residual power calculation value SEP1 relative to an axial reference line FRL on the head-up display;

[0007] Step 2: Convert the calculated first unit surplus power value SEP1 into a second unit surplus power value SEP2 based on the center of the velocity vector symbol on the head-up display.

[0008] Further, the calculation of the first unit residual power calculation value SEP1 relative to the axial reference line FRL on the head-up display includes the following steps:

[0009] S1: Real-time acquisition of inertial angle of attack AOA, pitch angle Pitch and indicated airspeed V IAS ;

[0010] S2: Take M consecutive data of the pitch angle Pitch data obtained before the current moment and average them to get the first pitch angle

[0011] S3: Based on the calculated first pitch angle And calculate the first pitch angle Calculation of inertial angle of attack (AOA) acquired synchronously Repeat the above steps N times

[0012] S4: Statistics of N consecutive calculations And take the average to get

[0013] S5: Set the first threshold a The calculated value is filtered to obtain the filtered like So otherwise

[0014] S6: averaging M consecutive data of the indicated airspeed VIAS data acquired before the current moment to obtain a first indicated airspeed V1, and repeating this step to continuously calculate the first indicated airspeed V1;

[0015] S7: reprocessing the first indicated airspeed V1 to obtain a reprocessed indicated airspeed V4;

[0016] S8: Calculate the first indicated airspeed change rate ΔV according to the reprocessed indicated airspeed V4, and repeat steps S6 to S8 to calculate ΔV N times;

[0017] S9: Count the first indicated airspeed change rate ΔV calculated for N consecutive times, and take the average to obtain the second indicated airspeed change rate

[0018] S10: Set a second threshold value b, which is used to The calculated value is filtered to obtain the filtered like So otherwise

[0019] S11: Exploitation and Calculate a unit residual power calculation value SEPX relative to the axial reference line FRL on the head-up display, and repeat the above steps to calculate SEPX N times;

[0020] S12: Count the SEPX calculated N times in succession and take the average to obtain the first unit residual power calculation value SEP1.

[0021] Further, the step S7 reprocesses the first indicated airspeed V1 to obtain the reprocessed indicated airspeed V4, including:

[0022] S71: taking two discontinuously calculated indicated airspeeds V1 from the continuously calculated first indicated airspeed V1, performing cross-average to obtain a second indicated airspeed V2, and repeating the above steps to calculate the second indicated airspeed V2;

[0023] S72: taking two discontinuously calculated second indicated airspeeds V2 from the continuously calculated second indicated airspeeds V2, and performing cross-average to obtain a third indicated airspeed V3, and repeating the above steps to continuously calculate the third indicated airspeed V3;

[0024] S73: averaging the N third indicated airspeeds V3 calculated continuously to obtain a reprocessed indicated airspeed V4.

[0025] Further, the calculation formula of the first indicated airspeed change rate ΔV calculated in step S8 according to the reprocessed indicated airspeed V4 is as follows:

[0026]

[0027] Where: t is the data transmission period, g is the gravitational acceleration, V4 Ntime+1 is the indicated airspeed after the previous reprocessing, V4 Ntime is the reprocessed indicated airspeed at the current moment.

[0028] Further, the step S11 utilizes and The formula for calculating the unit residual power SEPX relative to the axial reference line FRL on the head-up display is as follows:

[0029] Further, the step of converting the calculated first unit surplus power calculation value SEP1 into a second unit surplus power calculation value SEP2 based on the center of the velocity vector symbol on the head-up display comprises the following steps:

[0030] S13: Calculate the determination value d, d=SEP1-Pitch0-AOA0, where Pitch0 is the pitch angle at the current moment, and AOA0 is the inertial angle of attack at the current moment;

[0031] S14: setting a third threshold value c, and calculating the unit surplus power SEP2 based on the center of the velocity vector symbol on the head-up display at the current moment according to the determination value d and the criterion,

[0032] The present invention calculates a first unit residual power calculation value SEP1 relative to an axial reference line FRL on a head-up display; then converts the first unit residual power calculation value SEP1 into a second unit residual power calculation value SEP2 based on the center of a velocity vector symbol on the head-up display; converts the second unit residual power calculation value SEP2 into a digital signal and transmits it to the head-up display via a bus, so that the position of the SEP symbol can be displayed on the head-up display. The present invention uses an arithmetic mean value to eliminate errors caused by individual points according to mathematical error analysis theory, and the data obtained and the data generated in the calculation process are averaged. At the same time, the threshold is optimized and adjusted, so as to adjust the display range of the SEP symbol, so that the final result is closer to the true value, so that the SEP symbol in the pilot's field of view will not jump frequently, thereby ensuring the accuracy and readability of the SEP symbol display, and solving the problem of unstable SEP symbol display causing misjudgment by the pilot. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is the main flow chart of the present invention;

[0034] Figure 2 It is the overall flow chart of the present invention;

[0035] Figure 3 is a flow chart of step S7 of the present invention; DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0037] These and other aspects of the embodiments of the present invention will become clear with reference to the following description and drawings. In these descriptions and drawings, some specific implementations of the embodiments of the present invention are specifically disclosed to represent some ways of implementing the principles of the embodiments of the present invention, but it should be understood that the scope of the embodiments of the present invention is not limited thereto. On the contrary, the embodiments of the present invention include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0038] The relevant terms and units in the embodiments are shown in the following table:

[0039]

[0040]

[0041] Example: See Figures 1 to 3, a method for calculating a SEP symbol of the present invention includes: step 1: calculating a first unit residual power calculation value SEP1 relative to an axial reference line FRL on a head-up display; step 2: converting the calculated first unit residual power calculation value SEP1 into a second unit residual power calculation value SEP2 based on the center of a velocity vector symbol on the head-up display; converting the second unit residual power calculation value SEP2 into a digital signal and transmitting it to the head-up display via a bus, so that the position of the SEP symbol can be displayed on the head-up display, wherein calculating the first unit residual power calculation value SEP1 relative to the axial reference line FRL on the head-up display includes the following steps:

[0042] Step S1, real-time acquisition of inertial angle of attack AOA, pitch angle Pitch and indicated airspeed V IAS .

[0043] Step S2: average M consecutive data of the pitch angle Pitch data acquired before the current moment to obtain a first pitch angle

[0044] Specifically, this embodiment takes the pitch angles Pitch of the previous five cycles for averaging as an example, and the calculation is as follows:

[0045]

[0046] Among them: Pitch 1, Pitch 2, Pitch 3, Pitch 4, and Pitch 5 respectively represent the data of the pitch angles of the five cycles received previously.

[0047] Step S3, based on the calculated first pitch angle And calculate the first pitch angle Calculation of inertial angle of attack (AOA) acquired synchronously Repeat the above steps 5 times

[0048] Step S4: Count the values ​​obtained from 5 consecutive calculations. And take the average to get

[0049] Step S5, setting a first threshold a The calculated value is filtered to obtain the filtered like So otherwise

[0050] The first threshold a: In the speed-maintaining flight mode, the indicated airspeed should maintain a stable data, that is, the speed change rate of the indicated airspeed is 0. Therefore, the final SEP symbol display position is mainly determined by Decide if If the value is small, the change of SEP symbol on the display will not be obvious, which may cause the pilot to think that there is a display device failure causing the display symbol fluctuation. Therefore, it is necessary to The results eliminated small values ​​and invited pilots to The SEP symbols were evaluated and the results are shown in Table 1 below.

[0051] Table 1

[0052]

[0053]

[0054] Step S6, averaging 5 consecutive data of the indicated airspeed VIAS data acquired before the current moment to obtain a first indicated airspeed V1, and repeating this step to calculate the first indicated airspeed V1 5 times.

[0055] S7: reprocessing the first indicated airspeed V1 to obtain a reprocessed indicated airspeed V4;

[0056] Specifically, the steps include:

[0057] S71: taking two discontinuously calculated indicated airspeeds V1 from the continuously calculated first indicated airspeed V1, cross-averaging them to obtain a second indicated airspeed V2, and repeating the above steps to calculate the second indicated airspeed V2;

[0058] Specifically, the calculation is as follows:

[0059] V2=(V1 Ntime+4 + V1 Ntime+0) / twenty two)

[0060] Where V1 Ntime+4 V1 is the fourth first indicated airspeed before the current moment. Ntime+0 is the first indicated airspeed at the current moment.

[0061] S72: taking two discontinuously calculated second indicated airspeeds V2 from the continuously calculated second indicated airspeeds V2, performing cross-average to obtain a third indicated airspeed V3, and repeating the above steps to continuously calculate the third indicated airspeed V3.

[0062] Specifically, the calculation is as follows:

[0063] V3=(V2 Ntime+7 + V2 Ntime+0) / twenty three)

[0064] Where V2 Ntime+7 V2 is the seventh second indicated airspeed before the current time.Ntime+0 is the second indicated airspeed at the current moment.

[0065] S73: averaging the five consecutively calculated third indicated airspeeds V3 to obtain a reprocessed indicated airspeed V4.

[0066] Specifically, in this embodiment, the average value of five consecutive third indicated airspeeds V3 is calculated as follows:

[0067] V4=(V3 Ntime+1 +V3 Ntime+2 +V3 Ntime+3 +V3 Ntime+4 +V3 Ntime+5) / 5 (4)

[0069] Among them, V3 Ntime+1 V3 is the first third indicated airspeed before the current time. Ntime+2 + is the second third indicated airspeed before the current moment, and so on.

[0070] Step S8, calculating a first indicated airspeed change rate ΔV according to the reprocessed indicated airspeed V4, and repeating steps S6 to S8 to calculate ΔV five times;

[0071] Specifically, the calculation is as follows:

[0072]

[0073] Where: t is the data transmission period, g is the gravitational acceleration, V4 Ntime+1 is the indicated airspeed after the previous reprocessing, V4 Ntime is the reprocessed indicated airspeed at the current moment.

[0074] Step S9: Count the first indicated airspeed change rate ΔV calculated for five consecutive times and take the average to obtain the second indicated airspeed change rate

[0075] Specifically, this embodiment takes the average processing of five consecutive indicated airspeed change rates ΔV as an example, and the calculation is as follows:

[0076]

[0077] Where, ΔV Ntime+1 is the first indicated airspeed change rate before the current moment, ΔV Ntime+2 It is the second indicated airspeed change rate before the current moment, and so on.

[0078] Step S10, setting a second threshold value b, the second threshold value b is used to The calculated value is filtered to obtain the filtered like Then Otherwise

[0079] Among them, the second threshold b: in the flight mode with the angle of attack maintained, at this time the pitch angle and the inertial angle of attack are equal. Therefore, the final display position of the SEP symbol is mainly determined by If The value is small, and the change of the SEP symbol in the display is not obvious, which will cause the pilot to think that there is a display device failure resulting in the fluctuation of the display screen symbols. Therefore, it is necessary to Eliminate the tiny values in the results. Set the pitch angle and the inertial angle of attack to be equal on the simulator, and specifically invite the pilot to evaluate the SEP symbol. The results are shown in Table 2

[0080] Table 2

[0081]

[0082] S11: Use And Calculate the calculated value SEPX of the unit remaining power relative to the axial reference line (FRL) on the head-up display, and repeat the above steps to calculate SEPX N times; the specific calculation formula of SEPX is as follows

[0083]

[0084] S12: Statistically analyze the SEPX calculated continuously N times, and take the average to obtain the first calculated value SEP1 of the unit remaining power

[0085] Converting the calculated first calculated value SEP1 of the unit remaining power into the second calculated value SEP2 of the unit remaining power based on the center of the speed vector symbol on the head-up display includes the following steps

[0086] S13: Calculate the determination value d, d = SEP1 - Pitch0 - AOA0, where Pitch0 is the pitch angle at the current moment, and AOA0 is the inertial angle of attack at the current moment

[0087] S14: Set the third threshold c to determine the display range, and calculate the unit remaining power SEP2 at the current moment based on the center of the speed vector symbol on the head-up display according to the determination value d and the criterion That is, when d > 34.91 mrad (the third threshold), SEP2 is AOA0 + 34.91 mrad; when d < -34.91 mrad, SEP2 is AOA0 - 34.91 mrad; when -34.91 mrad < d < 34.91 mrad, SEP2 is AOA0

[0088] Among them, the third threshold c: Since the display positioning of the SEP symbol on the display moves up and down with the velocity vector symbol as the center, the pilot needs to observe the SEP symbol in real time when observing the velocity vector symbol. Therefore, the pilots are specially invited to evaluate the maximum positive limit of the SEP symbol to determine the display range. The results are shown in Table 3.

[0089] Table 3

[0090]

[0091]

[0092] The present invention eliminates the large error theory caused by individual points through arithmetic mean, that is, taking the arithmetic mean of multiple data to make the final result closer to the true value. Each average can eliminate the sensor output error caused by the sensor, for example: for the indicated airspeed V IAS The five average values ​​are calculated to ensure that the result is closer to the actual indicated airspeed.

[0093] It is worth noting that when the simulator performs algorithm simulation, the designers found in the process of determining the second threshold that if the indicated airspeed change rate is directly calculated using the first indicated airspeed V1, the final SEP symbol jump is still large. For this reason, a reprocessing step, namely steps S71 to S73, is added when taking the indicated airspeed calculation index. The use of cross-average can further eliminate the errors generated by the computer in the calculation process.

[0094] The above-described embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A method for calculating a SEP symbol, characterized in that: include: Step 1: Calculate a first unit residual power calculation value SEP1 relative to an axial reference line FRL on the head-up display; Step 2: converting the calculated first unit surplus power calculation value SEP1 into a second unit surplus power calculation value SEP2 based on the center of the velocity vector symbol on the head-up display; The calculation of the first unit residual power calculation value SEP1 relative to the axial reference line FRL on the head-up display comprises the following steps: S1: Real-time acquisition of inertial angle of attack AOA, pitch angle Pitch and indicated airspeed V IAS ; S2: Take M consecutive data of the pitch angle Pitch data obtained before the current moment and average them to get the first pitch angle S3: Based on the calculated first pitch angle And calculate the first pitch angle Calculation of inertial angle of attack (AOA) acquired synchronously Repeat the above steps N times S4: Statistics of N consecutive calculations And take the average to get S5: Set the first threshold a The calculated value is filtered to obtain the filtered like So otherwise S6: averaging M consecutive data of the indicated airspeed VIAS data acquired before the current moment to obtain a first indicated airspeed V1, and repeating this step to continuously calculate the first indicated airspeed V1; S7: reprocessing the first indicated airspeed V1 to obtain a reprocessed indicated airspeed V4; S8: Calculate the first indicated airspeed change rate ΔV according to the reprocessed indicated airspeed V4, and repeat steps S6 to S8 to calculate ΔV N times; S9: Count the first indicated airspeed change rate ΔV calculated for N consecutive times, and take the average to obtain the second indicated airspeed change rate S10: Set a second threshold value b, which is used to The calculated value is filtered to obtain the filtered like So otherwise S11: Exploitation and Calculate a unit residual power calculation value SEPX relative to the axial reference line FRL on the head-up display, and repeat the above steps to calculate SEPX N times; S12: Counting SEPX obtained by N consecutive calculations and taking the average to obtain a first unit residual power calculation value SEP1; The step of converting the calculated first unit surplus power calculation value SEP1 into a second unit surplus power calculation value SEP2 based on the center of the velocity vector symbol on the head-up display comprises the following steps: S13: Calculate the determination value d, d=SEP1-Pitch0-AOA0, where Pitch0 is the pitch angle at the current moment, and AOA0 is the inertial angle of attack at the current moment; S14: setting a third threshold value c, and calculating the unit surplus power SEP2 based on the center of the velocity vector symbol on the head-up display at the current moment according to the determination value d and the criterion, 2. A method for calculating a SEP symbol as claimed in claim 1, characterized in that: The step S7 reprocesses the first indicated airspeed V1 to obtain the reprocessed indicated airspeed V4, comprising: S71: taking two discontinuously calculated indicated airspeeds V1 from the continuously calculated first indicated airspeed V1, performing cross-average to obtain a second indicated airspeed V2, and repeating the above steps to calculate the second indicated airspeed V2; S72: taking two discontinuously calculated second indicated airspeeds V2 from the continuously calculated second indicated airspeeds V2, and performing cross-average to obtain a third indicated airspeed V3, and repeating the above steps to continuously calculate the third indicated airspeed V3; S73: averaging the N third indicated airspeeds V3 calculated continuously to obtain a reprocessed indicated airspeed V4.

3. A method for calculating a SEP symbol as claimed in claim 1, characterized in that: The calculation formula of the first indicated airspeed change rate ΔV in step S8 is calculated according to the reprocessed indicated airspeed V4 as follows: Where: t is the data transmission period, g is the gravitational acceleration, V4 Ntime+1 is the indicated airspeed after the previous reprocessing, V4 Ntime is the reprocessed indicated airspeed at the current moment.

4. A method for calculating a SEP symbol as claimed in claim 1, characterized in that: The step S11 utilizes and The formula for calculating the unit residual power SEPX relative to the axial reference line FRL on the head-up display is as follows:

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