RU2774083C1 - Method for ensuring the vortex safety of an aircraft - Google Patents

Abstract

FIELD: flight safety.

SUBSTANCE: invention relates to a method for ensuring the vortex safety of the flight of an aircraft. To ensure vortex safety, a certain set of parameters is obtained from the on-board system for collecting, monitoring, processing and recording flight information from the vortex generator and this aircraft, environmental parameters in the area of the aircraft location, in a certain way the geometric dimensions and location of the vortex wake danger zone are determined, the probability of the aircraft getting there is calculated, the moments of the current roll of the aircraft are calculated, compared with the values corresponding to with the flight plan and in case of exceeding the permissible values, the crew is notified and a maneuver is carried out to exit the danger zone.

EFFECT: flight safety is improved.

1 cl, 4 dwg

Description

The present invention relates to the field of flight safety and can be used to notify the crew or the operator of aircraft (LA) about the likelihood of a vortex generator falling into the vortex wake of the aircraft, as well as issuing information about getting into a dangerous vortex zone to the control system and the limitation subsystem limiting flight parameters of the aircraft for generating a signal to perform a maneuver.

Ensuring the vortex safety of aircraft (LA) flights is an urgent problem, as the aircraft continues to get into the dangerous zone of the wake vortex. So, according to NATS (UK air navigation services provider) for 2018, the frequency of entry into the wake vortex from aircraft increased from 1.8 to 6.2 times per 100 thousand flight hours.

One of the ways to improve the safety of aircraft flights is to provide the pilot with real-time information about the actual impact of the wake vortex on the movement of the aircraft.

At the same time, information should be provided on the degree of danger of being in the vortex zone with the possibility of forming a maneuver to exit the dangerous zone, and, as a result, it is advisable to create an aircraft vortex safety system on this basis.

The following technical solutions are known from the art.

There is a known method to prevent an aircraft from getting into a vortex wake (see, for example, Zolotukhin V.V. "Modeling vortex wakes in air traffic control problems". International journal "Software products and systems", No. 1, 2011), including the following steps:

- receiving flight data from an aircraft generator that has fallen into the field of view of an aircraft subscriber;

- calculation of the characteristics of the vortex wake: damping time, length, height of lowering, dimensions of the semi-axes of the vortex ellipse of the vortex wake;

- obtaining data on the trajectory of movement for a period of time equal to the estimated decay time;

- checking if the aircraft generator remains in view. If it remains, then carry out an exchange of flight data with it, observe its vortex wake (or part of it), which is in the visibility zone;

- if the aircraft generator is out of sight, check if its vortex wake has disappeared. If it disappeared, the algorithm terminates;

- determining by calculation whether maintaining the current heading will lead to falling into the vortex wake. If not, continue on the current course;

- check whether the aircraft will fall into the vortex wake at the current course, calculate the size of the wake at the intersection point by the moment of intersection. If the eddies disappear, continue on the current course, the iteration ends;

- if during the calculation it turns out that the vortices at the intersection point do not disappear, the optimal maneuver should be chosen to avoid the aircraft subscriber getting into the vortex wake.

Using this method, the dimensions of the vortex ellipse and its location are determined by calculation until the moment of attenuation, and if in this case the aircraft user enters the calculated vortex ellipse, then he is prescribed to perform the necessary maneuver. However, when assessing the danger of the influence of the vortex wake by this method, significant errors in determining the calculated dimensions of the vortex ellipse are possible.

A known method of warning against a possible entry of an aircraft into the danger zone of the vortex wake (RF patent No. 2324203 with priority dated 25.07.2003, IPC: G01S 13/95), including obtaining information about the configuration, location and orientation of the aircraft relative to the inertial coordinate system at the current time , obtaining and saving information about the motion parameters of the vortex generator (VG) and its position, geometric and mass characteristics relative to the same coordinate system at the current time, obtaining information about the environmental parameters in the area of joint placement of aircraft and GV, determining the trajectory and intensity of the vortex trace of the GW as a set of trajectories of the centers of vorticity regions generated by the specified GW in the inertial coordinate system at the current time, saving information about the coordinates of the points of the trajectory and the intensity of the vortex wake of the GW as a set of trajectories of the centers of vorticity regions in the inertial coordinate system, timing lead, during which the aircraft can at least perform a flight path change maneuver that ensures the aircraft avoids the GW wake after warning of the possibility of hitting it, calculating the lead distance equal to the distance covered by the aircraft during the lead time, simulate the control plane, located in the space in front of the aircraft, and determine the predicted time of the flight of the aircraft through the specified control plane in the inertial coordinate system, and also indicate to the user the event that the distance to the danger zone of the vortex wake of the specified GW is equal to zero.

This known method informs the user about the possibility of a dangerous situation, however, the accuracy of finding the coordinates of the selected dangerous vortex zone and, accordingly, the probability of an aircraft getting into it is determined by the accuracy of calculating the characteristics of the dangerous zone without confirmation by actual measurements.

In addition, the implementation of this method will require the installation of expensive lidars on each aircraft and the creation of systems integrated into a single information system located on aircraft, ships, airfields, air traffic control points, etc., which is associated with the need for significant financial costs and in in some cases it is inappropriate.

A known method is known to prevent an aircraft from entering the vortex wake of a vortex generator aircraft (RF patent No. 2695249 with priority dated 11/29/2018, IPC: G08G 5/02).

To implement the method, information is obtained about the configuration, location and orientation of the aircraft and the aircraft generating vortices, as well as information about the environmental parameters at the current time, determine the geometric characteristics of the danger zone of the vortex wake, provide visual information to the crew about the risk of getting into the danger zone of the vortex track in a certain way, while reducing the pilot load on the pilot.

However, the presented method ensures the accuracy of determining the dangerous zone of the vortex wake and the need to perform an evasive maneuver with calculation accuracy without confirming the actual position of the vortex wake and the aircraft.

A known method for ensuring the vortex safety of an aircraft in the vortex wake of an aircraft-generator of vortices (RF patent No. 2477893 with priority dated 09/30/2011, IPC: G08G 5/02), in which the transfer of information about the vortex wake created by it, speed flight, coordinates, transmission time by air-to-air radio communication in the broadcast mode and / or in the point-to-point mode and the subsequent reception of this information by the aircraft subscriber or aircraft subscribers.

The aircraft subscriber performs current calculations, corresponding to the parameters of the vortex wake coming to it from the aircraft vortex wake generator, of the magnitude of the disturbing roll moment acting on it and measurements of the vortex situation in front of the aircraft subscriber, based on the results of which it also calculates the disturbing roll moment, and then performs comparison of the values of the disturbing roll moment, calculated from the results of these measurements, with the values of the disturbing roll moment, obtained by calculation based on the transmitted information from the aircraft vortex wake generator, while the data required to determine the vortex situation in front of the aircraft subscriber are obtained by measurements using static sensors pressure set at the front "critical" points of its wing, and the largest of the calculated values of the perturbing roll moment is chosen as the expected effect of the vortex wake on the aircraft subscriber and the selected value is entered as a corrective value into the control system of the aircraft subscriber.

However, this method ensures that the pilot is informed about falling into the vortex wake only if the vortex has entered the pressure receiver, and in order to determine the rarefaction in the vortex, which determines the increment in the roll moment, it is necessary to know the static pressure of the surrounding atmosphere unperturbed by the vortex, and this is not known in advance. . In addition, in this patent, the decision on the degree of danger is recommended to be taken from a larger value between calculation and measurement, which may unreasonably overestimate the degree of danger of the vortex effect.

Known system and method for detecting the vortex wake of an aircraft (patent US8478459).

The system includes a means for determining the aircraft roll angle, for example, an inertial platform, a means for determining the calculated/experimental dependences of the change in the aircraft roll angle on the flight time when exposed to vortex disturbances for various characteristics of the aircraft generator of vortices (speed, mass, wing span ) and environmental conditions (wind, temperature in the space between the aircraft), a means for comparing the angle of roll of the aircraft and the obtained dependences of the change in the angle of roll on the flight time under the influence of vortex disturbances and a means for notifying the pilot of the aircraft about the detection of a vortex wake, when the mismatch between the compared values is less specified threshold value or equal to it.

When implementing the method, the roll angle of the aircraft that perceives vortex disturbances is determined, the dependences of the change in the roll angle of the aircraft on the flight time are determined when it is exposed to vortex disturbances from the vortex generator aircraft, and these dependences can be obtained from the results of simulation or flight tests. Then, the value of the roll angle of the aircraft perceiving vortex disturbances is compared with the obtained dependences of the roll angle change on the flight time, and the crew is warned about the danger when the value of the registered mismatch is less than or equal to the specified threshold value.

The disadvantage of this method is that it is necessary to know in advance the calculated/experimental dependencies that determine the effect of the wake vortex on the roll of the aircraft affected by it, in time, taking into account the characteristics of the aircraft and the surrounding atmosphere. In this case, the turbulence (stochastic) of the atmosphere, the main factor in the development and decay of the vortex wake, is determined indirectly, for example, from measurements of ground control stations. Consequently, the parameters of the vortex wake and its coordinates are also of a probabilistic nature, which can lead to an erroneous assessment of the vortex hazard, both in the direction of its exaggeration and understatement. Also, the implementation of this method does not provide for the formation of signals for the aircraft to avoid the dangerous zone of the vortex wake, but only gives a signal to the crew about the danger of entering the vortex wake in front of the flying aircraft, significantly limiting the time for the crew to perform a maneuver. At the same time, the notification of the aircraft control system about the vortex danger in this method is not provided, which increases the load on the crew.

This method in technical essence is the closest to the claimed invention and can act as a prototype.

The task to be solved by this invention is to create a method for ensuring the vortex safety of an aircraft, which provides with high accuracy and reliability the determination of the degree of danger of the impact of the vortex wake on the aerodynamic and flight characteristics of the aircraft when achieving timely notification of the crew or the operator of the aircraft in real time about the probability of hitting The aircraft enters the dangerous zone of the vortex wake or actually gets into it with the possibility, in this case, of generating and issuing signals to the control control system and the subsystem for limiting flight parameters to perform a maneuver to exit this dangerous vortex zone.

The technical result consists in the possibility of timely registration in real time of the degree of danger of vortex disturbances exerted on the aircraft while providing advance information to the crew or operator about their possible adverse effects, with high accuracy and reliability, for generating signals to the control control system and the subsystem for limiting flight parameters on maneuver to exit this dangerous vortex zone.

The technical result of the claimed invention is achieved by implementing a method for ensuring the vortex safety of an aircraft (LA) flight, in which data on the location, flight performance and motion parameters of the aircraft vortex generator are obtained from the on-board system for collecting, controlling, processing and recording flight information. information about the location, performance and flight characteristics of an aircraft that perceives vortex disturbances, and its limitations, obtain information about the environmental parameters in the area of the location of this aircraft, determine the geometric characteristics and location of the dangerous zone of the vortex wake of the aircraft vortex generator, calculate the probability of hitting the aircraft into the danger zone of the wake vortex, determine in real time the current roll moment of the aircraft corresponding to the flight plan, determine in real time the moment of roll created by the aircraft controls, characterized in that in real time and notify the crew or the aircraft operator about the probability of getting into the dangerous zone of the vortex wake and the forecast of its development, issue this information to the control system and the subsystem for limiting flight parameters, determine the amount of mismatch between the values of the current roll moment of the aircraft, corresponding to the flight plan, and the roll moment, created by the aircraft controls, as the difference between them, when increased values of this mismatch value are reached, the crew or the aircraft operator is notified in real time about the actual entry into the wake vortex, a signal is given that the aircraft enters the wake vortex to the control control system and the subsystem for limiting flight parameters , if the value of this mismatch exceeds a predetermined threshold value, a signal is generated and issued to these systems to perform a maneuver to exit the dangerous vortex zone.

In the claimed method, the notification of the crew or the operator of the aircraft in real time about the probability of getting into the dangerous zone of the vortex wake, determined on the basis of the calculated characteristics of the danger zone and information about the location of the aircraft, and the registration of dangerous vortex disturbances exerted on the aircraft by other aircraft, is simultaneously implemented, by the magnitude of the mismatch between the estimates of the current roll moment corresponding to the flight plan and the roll moment created by the aircraft controls, providing the possibility of timely registration in real time of the degree of danger of vortex disturbances exerted on the aircraft during its flight, with high accuracy and reliability, and the crew or the aircraft operator is informed about the possible dangerous effects of the wake vortex until the moment of its adverse effect on the movement of the aircraft. At the same time, it is possible to perform an aircraft maneuver to exit the dangerous zone of the vortex wake by generating and issuing appropriate signals to the control system and the subsystem for limiting flight parameters when the value of the mismatch of the specified threshold value is reached, thereby increasing the flight safety of the aircraft.

The invention will now be described with reference to the drawings.

Figure 1 shows an illustration of the process of formation of a dangerous vortex wake by the A-380 aircraft.

Figure 2 shows a diagram of modeling the effect of vortex disturbances created by the aircraft-generator of vortices on the movement of the aircraft.

Figure 3 shows the dependence of the change in the angle of roll of the aircraft, caught in the zone of the vortex wake from the aircraft A-380, from the time of flight.

Figure 4 shows the dependence of the change in the magnitude of the deflection angle of the ailerons of the aircraft, which fell into the zone of the vortex wake from the aircraft A-380, on the flight time, where 1 is the dependence of the change in the deflection of the right aileron on the flight time, 2 is the dependence of the change in the deflection of the left aileron from flight time.

The way to ensure the vortex safety of the aircraft is as follows.

To implement the method, from the onboard system for collecting, controlling and processing flight information, the aircraft receive information about the location, flight performance, motion parameters of the aircraft vortex generator, receive information about the location, flight performance, flight characteristics of the aircraft that perceives vortex disturbances, and its restrictions, receive information about the environmental parameters in the area of the location of the aircraft.

Then the geometric characteristics and the location of the dangerous zone of the vortex wake are calculated.

The calculation of the predicted dangerous zone of the vortex wake is performed according to the following algorithm:

- the initial circulation of the vortex behind the aircraft generator is calculated:

where g is the free fall acceleration, m/s ² ;

ρ - air density, kg / m ³ ;

m - aircraft weight, kg;

V - aircraft speed, m/s;

- начальный размах вихрей, B - размах крыла ЛА, м;

- initial vortex span, B - aircraft wing span, m;

- Calculate the vortex attenuation with distance from the aircraft vortex generator and the speed of their descent (technical report to support the safety issue for the ICAO recategorization of wake turbulence standards):

where:

q - atmospheric turbulence;

x - distance from the aircraft.

(A.M. Gaifullin Mathematical model of aircraft aerodynamics in the vortex wake, scientific notes of TsAGI, volume 10 LI, 2010, No. 4);

- the change in coordinates is calculated, the mathematical expectation of the centers of vortices:

where Z ₀ - initial coordinate;

W - wind speed;

τ - time.

(V.V. Zolotukhin Modeling of vortex wakes in air traffic control problems, Software products and systems, No. 1, 2011).

As a result of the calculations, a dangerous zone of the vortex wake from the LA generator of vortices with known geometric dimensions and coordinates, determined taking into account the stochasticity of the atmosphere (Fig. 1), is formed, in which the LA can be located at a given time with a certain probability.

Based on the information received about the wake vortex danger zone from the aircraft vortex generator, the probability of the aircraft getting into this wake vortex danger zone is determined and a forecast of its development is issued, after which the crew or the aircraft operator is notified about the probability of getting into the wake vortex danger zone. This information is also issued to the control control system and the subsystem for limiting flight parameters.

The registration of the actual entry of the aircraft into the danger zone of the wake vortex in front of the flying aircraft and the assessment of the degree of danger of the effects of vortex disturbances on the aircraft is carried out according to a diagnostic feature, which is proposed to choose the value of the increment of the roll moment of the aircraft, defined as the difference between the value of the current roll moment of the aircraft, corresponding to the flight plan , and the magnitude of the roll moment created by the aircraft controls, exceeding which a certain threshold value determined for each type of aircraft indicates the presence of a moment created by a factor external to the aircraft, that is, a wake vortex.

The current roll moment M _t is determined from the expression:

The estimate of the dimensionless coefficient of the current roll moment m _t is determined from the following equation:

where ω _x , ω _y , ω _z - angular velocities relative to associated axes, rad/s;

I _x , I _y , I _z - moments of inertia about the associated axes of the associated coordinate system, kg×m ² ;

l - wingspan and length of the average aerodynamic chord, m;

S - equivalent wing area, m ² ;

q=ρ _H V ² /2 - velocity pressure, Pa;

ρ _H - air density at flight altitude, kg/m ³ ;

V - true airspeed, m/s.

To find the derivative of the angular velocity of the roll, numerical differentiation is performed according to the formulas presented in [Vasilchenko K.K., Leonov V.A., Pashkovsky I.M., Poplavsky B.K. Aircraft flight tests. M.: Mashinostroenie. 1993], which use polynomial smoothing on a sliding interval

The derivative estimates have good smoothing properties and are also unbiased and efficient.

When using a fourth-order smoothing polynomial, the coefficients are calculated by the formula:

- интервал дискретизации.where

- sampling interval.

As a rule, m =5 is chosen.

To find an estimate of the dimensionless coefficient of the roll moment created by the controls and other motion parameters, it is proposed to take the following model as a basis:

which includes components of the moment of roll, created by the angle of slip, angular velocities ω _x , ω _y , rudder δ _n , ailerons δ _e and spoilers δ _int .

For the task of detecting a vortex wake, taking into account the high signal power, it is proposed to calculate the moment from the controls by the formula:

Based on the found m _oy , the roll moment is calculated from the expression:

Next, the diagnostic feature ΔM is calculated as the difference between the value of the current roll moment of the aircraft and the value of the roll moment created by the aircraft controls:

In the case when the value of this sign takes on increased values, the crew or the aircraft operator is notified about the actual entry into the dangerous zone of the vortex wake by means of an alarm. And also, at the same time, this information is transmitted to the control control system and the subsystem for limiting flight parameters.

If the value of this diagnostic feature exceeds a certain predetermined threshold value ε, a signal is generated and issued to the control control system and the subsystem for limiting flight parameters to perform a maneuver to exit the dangerous vortex zone.

The threshold value is determined for each type of aircraft based on the simulation results.

The crew is informed about the probability of getting into the danger zone of the vortex wake, about the actual presence in the vortex wake, about the forecast of the time to reach the threshold value of the mismatch of the roll moments is carried out by a text message on the signal field of the frame of the crew notification system or by a text message on the screen of the meteorological radar similarly to the message about the wind shear. The message is accompanied by an audible signal.

In the future, the proposed method for ensuring the vortex safety of the flight of the aircraft is explained by the results of simulation using a dynamic model of the movement of the aircraft, taking into account the influence of the vortex wake (figure 2).

The proposed method for ensuring vortex flight safety is implemented on a simulation complex, as a result of which an assessment was made of the effect of the vortex wake from the A380 on the dynamics of an aircraft that perceives these disturbances.

The simulation results shown in figure 3 and figure 4, represent the dependence of the change in the angle of roll and angles of deflection of the ailerons on the flight time.

In accordance with Fig.3, Fig.4, up to the 10th second, a uniform flight was simulated in an undisturbed (standard) atmosphere, from the 10th to the 35th second, the situation was simulated corresponding to the entry of the aircraft into the vortex wake and flight in this dangerous zone , from the 35th to the 37th second - the exit of the aircraft from the vortex wake, from the 37th to the 50th second - the flight of the aircraft in the undisturbed atmosphere.

The signal for the aircraft to avoid the dangerous vortex zone was given at the 35th second, in 2 seconds the aircraft left the vortex wake, the ailerons returned to their original position.

As a result of modeling, it was found that the entry of an aircraft into the vortex wake from the aircraft generator of vortices is characterized by a change in the values of the parameters of the flight control system:

- orientation angles;

- moments of inertia;

- aileron deflection angles;

- deflection angles of spoilers.

At the same time, vortex disturbances affect the roll of the aircraft to a greater extent.

The simulation results confirmed the operability of the proposed method for ensuring vortex safety with the formation of a signal for the aircraft to evade the dangerous zone of the vortex wake and perform a maneuver.

Claims (1)

A method for ensuring the vortex safety of an aircraft (LA) flight, in which data on the location, flight performance and motion parameters of the aircraft vortex generator are obtained from the on-board system for collecting, controlling, processing and recording flight information, information is obtained on the location, flight performance and flight characteristics of an aircraft that perceives vortex disturbances and its limitations, obtain information about the environmental parameters in the area of the location of this aircraft, determine the geometric characteristics and location of the dangerous zone of the vortex wake of the aircraft vortex generator, calculate the probability of the aircraft entering the dangerous zone of the vortex wake, determine in real time, the current roll moment of the aircraft, corresponding to the flight plan, determines in real time the moment of roll created by the aircraft controls, which differs in that the crew or the aircraft operator are notified in real time about the likelihood of falling into the danger zone wake vortex wake and the forecast of its development, issue this information to the control system and the subsystem for limiting flight parameters, determine the amount of mismatch between the values of the current aircraft roll moment corresponding to the flight plan, and the roll moment created by the aircraft controls, as the difference between them, when increased values of this mismatch value in real time notify the crew or the aircraft operator about the actual entry into the wake vortex, give a signal about the aircraft getting into the wake vortex to the control control system and the subsystem for limiting flight parameters, if the value of this mismatch exceeds the specified threshold value , form and issue a signal to these systems to perform a maneuver to exit the dangerous vortex zone.

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