CN115688986A - Aircraft landing distance prediction method - Google Patents

Abstract

The invention provides a method for predicting the landing distance of an airplane, which comprises the following steps: reading landing information input by a pilot in a cockpit, flight state parameters of an airplane in each avionic device, runway information of a destination and terrain information; judging the current flight stage of the airplane; preprocessing data input by external equipment to obtain data errors; and step four, calculating the standard landing distance according to the current position coordinates and flight phases of the airplane by combining the coordinates and length information of the runway and the surface condition of the runway in the runway database.

Description

Aircraft landing distance prediction method

Technical Field

The invention relates to the technical field of avionics, in particular to a method for predicting the landing distance of an airplane.

Background

The current aircraft has mature methods and products in the aspects of navigation and landing guidance and control systems, but the aircraft still depends on pilot operation experience and skills during landing, and a corresponding method is not available for predicting the landing distance, so that runway rushing accidents caused by insufficient pilot experience may occur.

Disclosure of Invention

In view of this, embodiments of the present disclosure provide a method for predicting an aircraft landing distance, so as to achieve the purpose of providing an effective reference for aircraft landing.

The embodiment of the specification provides the following technical scheme: an aircraft landing distance prediction method comprises the following steps: reading landing information input by a pilot in a cockpit, flight state parameters of an airplane in each avionic device, runway information of a destination and terrain information; judging the current flight stage of the airplane; thirdly, preprocessing data input by external equipment to obtain data errors; and step four, calculating a standard landing distance according to the current position coordinate and the flight phase of the airplane and by combining the coordinate and the length information of the runway in the runway database and the surface condition of the runway.

Further, step three includes step 3.1, checking the accuracy and validity status of the data in the terrain database and runway database.

Further, step three also includes step 3.2, through the formula H + -delta _H ＝k ₁₁ H _G +k ₁₂ H _GPS +k ₁₃ H _baro ±Δ _H And calculating the real altitude and the error range of the airplane, wherein H is the real altitude, delta H is the error range, K11, K12 and K13 are weight coefficients, HGPS is the GPS altitude, and Hbaro is the air pressure altitude.

Further, step three also includes step 3.3, passing formula V ± Δ V = k ₂₁ V _true +k ₂₂ V _eas +±Δ _V And calculating the real speed and the error range of the airplane, wherein V is the real speed, Δ V is the error speed, K21 and K22 are weight coefficients, vtrue is the vacuum speed, and Veas indicates the airspeed.

Further, step four includes step 4.1, when the aircraft is in the approach phase, using the formula

Calculating the horizontal predicted distance of the aircraft flying in the approach stage, wherein W is the weight of the aircraft, CD is the drag coefficient of the aircraft, T is the thrust of an engine, vf is the speed of leveling and landing, and alpha is an attitude angle,

is an engine mounting angle.

Further, step four includes step 4.2, when the aircraft is in the leveling phase, using the formula

Calculating the horizontal predicted distance that the airplane flies through in the leveling stage, wherein gamma = cos ^-1 L(ρ，W，T，v，C _D ) ρ is the air density, W is the aircraft weight, CD is the drag coefficient of the aircraft, T is the engine thrust, and S is the aircraft airfoil area.

Further, step four includes step 4.3, when if the aircraft is on the ground, using the formula

And calculating the predicted distance of the aircraft flying in the deceleration and sliding stage, wherein DB is the braking force of the aircraft, rho is the air density, W is the weight of the aircraft, CD is the drag coefficient of the aircraft, T is the thrust of an engine, S is the wing surface area of the aircraft, and sigma is the runway friction coefficient.

Further, step four includes step 4.4, by formula D = D _a +D _f +D _brakes And calculating to obtain the standard landing distance.

Compared with the prior art, the beneficial effects that can be achieved by the at least one technical scheme adopted by the embodiment of the specification at least comprise: the method can eliminate the influence of system errors on the prediction of landing distances, is based on the flight parameters of the airplane, is combined with runway data to carry out real-time analysis and synthesis, predicts the flying distance of the airplane in each flight stage by using flight mechanics, can dynamically adjust information in real time according to the operation of a pilot and the flight data, considers the influence of the system errors of the pilot in the design, and has good practicability.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

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

FIG. 2 is a schematic illustration of the flight staging in an embodiment of the present invention;

FIG. 3 is a flow chart of flight phase determination in an embodiment of the present invention;

FIG. 4 is a diagram of a model of a true altitude calibration algorithm in an embodiment of the present invention;

FIG. 5 is a model diagram of a true speed calibration algorithm in an embodiment of the invention.

Detailed Description

The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

Referring to fig. 1 to 5, an embodiment of the present invention provides a method for predicting a landing distance of an aircraft, which specifically includes the following steps: reading landing information input by a pilot in a cockpit, flight state parameters of an airplane in each avionic device, runway information of a destination and terrain information; judging the current flight phase of the airplane; preprocessing data input by external equipment to obtain data errors; and step four, calculating a standard landing distance according to the current position coordinate and the flight phase of the airplane and by combining the coordinate and the length information of the runway in the runway database and the surface condition of the runway.

The embodiment of the invention aims to eliminate the influence of system errors on land distance prediction, and based on flight parameters of the airplane, the flight parameters are combined with runway data to carry out real-time analysis and synthesis, and the flying distance of the airplane in each flight stage is predicted by using flight mechanics. The invention can dynamically adjust the information in real time according to the operation of the pilot and the flight data, and considers the influence of the system error of the pilot in the design, thereby having good practicability.

Specifically, as shown in the figure, the flight computer reads the information of the landing runway and landing environment input by the pilot from the cockpit panel, the flight parameter information of the airplane, such as longitude and latitude information, altitude, speed, course angle, track angle, glide slope angle, wheel load signal, etc., from the external avionics, and runway characteristic data, such as runway position, runway altitude, runway length, runway slope, runway surface friction coefficient, etc., from the airplane database according to the runway selection and position information. The method comprises the steps of judging the flight stage according to data of external data, determining the flight stage required from the current stage of the airplane to landing stop, preprocessing all data, checking the validity of input data and correcting the flight parameters of the airplane. And finally, inputting the processed data into a landing distance prediction algorithm to predict the horizontal distance required by the aircraft to land in the current state.

As shown in fig. 2 and 3, the aircraft enters the landing phase when it is aligned with the runway and within 3 nautical miles of the landing runway. Reading a wheel-mounted signal of the airplane, detecting the current attitude angle of the airplane if the airplane is in the air, and judging that the airplane is in a final approach stage when the attitude angle of the airplane is less than 0; when the attitude angle is larger than 0, judging that the airplane is in a leveling stage; if the airplane is on the ground, the airplane is in a deceleration rollout stage.

As shown in fig. 4, the algorithm is divided into radio altitude calibration, runway altitude calibration, GPS altitude calibration, modified altitude and true altitude calculation and selection. Inputting radio altitude, roll angle, position data and terrain data, and calibrating the true radio altitude H to the ground at the current moment of the aircraft _radio (ii) a Inputting runway height, position data and terrain data to calibrate real height H of runway _Rwy Thus, the height of the runway from the ground is H _G ＝H _Radio -H _Rwy (ii) a Inputting GPS sensor state and GPS height to obtain calibrated GPS height H _GPS Inputting standard air pressure height, corrected air pressure height, atmospheric static pressure and atmospheric static temperature, and calculating to obtain current actual atmospheric pressureAnd corrected barometric altitude H of the aircraft at temperature _baro . The real altitude calculation and selection algorithm determines H according to the flight phase, whether the flight path is over, the flight state and other information of the airplane _Radio 、H _GPS 、H _baro And the weights of the three heights are dynamically adjusted according to the precision of the data, and finally the real height and the error are obtained.

H±Δ _H ＝k ₁₁ H _G +k ₁₂ H _GPS +k ₁₃ H _baro ±Δ _H

As shown in fig. 5, the algorithm consists of vacuum speed calibration, true static pressure calibration and airspeed calibration and selection. Inputting the total atmospheric temperature, the static atmospheric pressure, the static atmospheric temperature, the standard atmospheric pressure altitude and the corrected atmospheric pressure altitude to calibrate the real atmospheric static pressure P _s And atmospheric density ρ according to the formula

Calculating the calibrated vacuum velocity V _true . The true airspeed calibration and selection algorithm confirms V according to the flying height and flying stage of the airplane _true And corrected indicated airspeed V _eas And dynamically adjusting the weights of the two airspeeds according to the data precision to finally obtain the real airspeed and the error.

V±Δ _V ＝k ₂₁ V _true +k ₂₂ V _eas +±Δ _V

The aircraft flies at the final approach phase generally according to a glide angle of 3 °, so the horizontal distance traveled by the aircraft is calculated as follows:

wherein W is the aircraft weight, C _D Is the drag coefficient of the aircraft, T is the engine thrust, V _f Is the speed when leveling and falling, alpha is the attitude angle,

is an engine mounting angle.

In the leveling stage, the attitude of the airplane is slowly lifted, the airplane keeps the angular speed change rate of-1 degree/s, the airplane is still in the air at the moment, and the leveling distance of the airplane flying is calculated according to the following formula:

wherein, γ = cos ^-1 L(ρ,W,T,v,C _D ) ρ is the air density, W is the aircraft weight, C _D The drag coefficient of the aircraft, T the engine thrust and S the aircraft airfoil area.

The deceleration running stage can be regarded as variable acceleration movement of the airplane on the ground, and the running distance calculation formula is as follows:

wherein D is _B Rho is the air density, W is the aircraft weight, C is the aircraft brake force _D The drag coefficient of the aircraft, T the engine thrust, S the aircraft airfoil area, and σ the runway friction coefficient.

And according to the current flight stage of the airplane, selecting a corresponding formula to calculate the horizontal distance flown by the airplane in the current flight stage and the distance flown by the airplane in the remaining flight stage, and adding all calculation results to obtain the landing distance prediction.

The above description is only exemplary of the invention and should not be taken as limiting the scope of the invention, so that the invention is intended to cover all modifications and equivalents of the embodiments described herein. In addition, the technical features, the technical schemes and the technical schemes can be freely combined and used.

Claims (8)

1. An aircraft landing distance prediction method is characterized by comprising the following steps:

reading landing information input by a pilot in a cockpit, flight state parameters of an airplane in each avionic device, runway information of a destination and terrain information;

judging the current flight stage of the airplane;

preprocessing data input by external equipment to obtain data errors;

and step four, calculating the standard landing distance according to the current position coordinates and flight phases of the airplane by combining the coordinates and length information of the runway and the surface condition of the runway in the runway database.

2. An aircraft landing distance prediction method according to claim 1, characterised in that step three includes step 3.1, checking the accuracy and validity status of the data in the terrain database and runway database.

3. Aircraft landing distance prediction method according to claim 2, characterized in that said third step further comprises a step 3.2 of determining the distance to the aircraft by means of the formula H ± Δ £ v _H ＝k ₁₁ H _G +k ₁₂ H _GPS +k ₁₃ H _baro ±Δ _H And calculating the real altitude and the error range of the airplane, wherein H is the real altitude, delta H is the error range, K11, K12 and K13 are weight coefficients, HGPS is the GPS altitude, and Hbaro is the air pressure altitude.

4. An aircraft landing distance prediction method according to claim 3, wherein said step three further comprises a step 3.3 of passing through the formula V ± Δ _V ＝k ₂₁ V _true +k ₂₂ V _eas +±Δ _V′ And calculating the real speed and the error range of the airplane, wherein V is the real speed, Δ V is the error speed, K21 and K22 are weight coefficients, vtrue is the vacuum speed, and Veas indicates the airspeed.

5. An aircraft landing distance prediction method according to claim 4, wherein said step four comprises a step 4.1 of using a formula when the aircraft is in the approach phase

Calculating the horizontal predicted distance of the aircraft flying in the approach stage, wherein W is the weight of the aircraft, CD is the drag coefficient of the aircraft, T is the thrust of an engine, vf is the speed of leveling and landing, and alpha is an attitude angle,

is an engine mount angle.

6. An aircraft landing distance prediction method according to claim 5, wherein said step four comprises a step 4.2 of using a formula when the aircraft is in the flare phase

Calculating the horizontal predicted distance of the flying plane in the leveling stage, wherein gamma = cos ^-1 L (ρ, W, T, v, CD), ρ is the air density, W is the aircraft weight, CD is the drag coefficient of the aircraft, T is the engine thrust, and S is the aircraft airfoil area.

7. An aircraft landing distance prediction method according to claim 6, wherein said fourth step comprises a step 4.3 of using a formula if the aircraft is on the ground

And calculating the predicted distance of the aircraft flying in the deceleration and sliding stage, wherein DB is the braking force of the aircraft, rho is the air density, W is the weight of the aircraft, CD is the drag coefficient of the aircraft, T is the thrust of an engine, S is the wing surface area of the aircraft, and sigma is the runway friction coefficient.

8. Aircraft landing distance prediction method according to claim 7, characterized in that said fourth step comprises a step 4.4, according to the formula D = D _a +D _r +D _brakes And calculating to obtain the standard landing distance.

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