RU2691984C1 - Method of estimating a low-level circuit of aircraft control - Google Patents

Abstract

FIELD: test equipment.SUBSTANCE: invention relates to test equipment and can be used for assessment of qualitative characteristics of low-flight flight control circuit. Method includes modeling of virtual terrain, use of dynamic model of tested aircraft (AC), decomposition of specified route of mountain relief on N (for example, 16) of elementary links, by which are elements of underlying relief, located on flight path, with characteristics specified in tactical-technical assignment. Creation of altitude-velocity area of specific aircraft, providing for unconditional flying over of obstacles. Set of links located in any order forms virtual mountain relief, which aircraft can fly at preset height of low-level mission (LLM). LLM is performed over each link in series in the entire permitted altitude-speed range of the LLM. Flight for estimation of low-level circuit (LLC) is performed in conditions of flat terrain in the absence of any real dangerous obstacles. Route is developed with reference to geographical coordinates (ϕ, X) defined by navigation system onboard of aircraft. To geographical coordinates (ϕ, X), determined by navigation system on board of aircraft, add shifts Δϕ, Δλ so that position of aircraft relative to digital map of area (DMA) corresponds to aircraft position on test route. Technical result of using “virtual” polygons is: use of standard on-board information systems instead of models; impact on aircraft of real disturbances (atmosphere turbulence, proximity of earth surface, etc.), moreover, perturbation is simple enough to imitate; absence of necessity in development of terrain profile model and abnormal digital computer onboard of aircraft; possibility of training and flight crew training in real flights; flightability assessment of LLC ergonomics; possibility of evaluating actuation of safety devices and dynamics of removal from dangerous height Hin presence of sufficient height margin; possibility of using obtained results, after checking ergodicity of relief, in statistical processing of materials; reducing the number of flights required for estimating LLC in mountainous areas; increased time of test flight and reduced fuel consumption and as a result – reduction of total number of test flights for assessment of LLC.EFFECT: technical result is expansion of functional capabilities.1 cl, 20 dwg

Description

The invention relates to test equipment and can be used to assess the quality characteristics of the control circuit of low-altitude flight. The currently existing method for evaluating the characteristics of low-altitude flight (FPM) is based on the use of means of external sensor measurements (VTI). The error in determining the coordinates of a spatial location when performing a profit center should not exceed 3 ... 10 m. To ensure the specified accuracy of trajectory measurements with existing VTI tools, it is necessary to create a dense network (15 ... 20) of measuring points (PI) located in close proximity from the tracks of the profit centers (at a distance of no more than 5 km), as well as ensure their further operation. Obviously, the task requires large financial expenditures, for the purchase of measuring equipment IP, construction and site preparation, for IP placement in remote mountainous areas, for maintenance and operation of IP.

At the same time, the evaluation of the low-altitude contour (MSC) during the tests will not be obtained in full, since the selected “optimal” route will not provide an examination of all the characteristics and will be essentially the only one that allows to carry out the assessment only in two directions - back and forth. The order of the mountain obstacles will be unchanged in accordance with the existing mountain relief of the landfill. It should be noted that in the case of an assessment using a mountain range, the task of ensuring flight safety becomes an essential factor for successful testing and will require the creation of a full-scale semi-natural stand to check the fail-safety of the profit center control loop when entering failures of various kinds (checks in flight tests are unacceptable ), will require and test the adequacy of the model "relief-environment-LA." Each element of the model will have its own assumptions that, in the end, will lead to the presence of unexplored characteristics of the profit center. However, if there is a data bank on the basic aerodynamic characteristics, taking into account the characteristics of the aircraft layout and the availability of the calculation methodology, it is possible to develop a method for evaluating the effectiveness of aircraft flight navigation systems in the profit center mode in the early stages of design.

The absence of test sites and specialized equipment for external trajectory measurements for testing aircraft control MVK in profit center mode necessitates the development of a less costly, safe from the point of view of preventing collision with an obstacle and a method of estimating MVK more realistic to real flights using “virtual” polygons. The integration of modern on-board measurement technologies and methods of reproducing the terrain field will allow creating a technology for the synthesis of virtual landfills, and developing appropriate methods for ground and flight tests of the aircraft control aircraft MVK with significantly lower costs. Prospective military aircrafts presented today for testing have high-precision on-board measuring systems, the recording of which data (after confirming their accuracy characteristics) can be considered as trajectory measurements in test flights. The concept of a “virtual” polygon can be represented, for example, as follows. The flight to the evaluation of the MVK is performed in a flat terrain in the absence of any dangerous obstacles. Offsets Δφ, Δλ are added to the geographic coordinates (φ, λ) determined by the navigation system onboard the aircraft so that the position of the aircraft relative to the digital map of the real terrain (CKM) corresponds to the position of the aircraft on the test track of the virtual terrain (slightly intersected, hilly, mountainous chain of mountains, water surface, etc.). Front View Locator and

radio altimeter at the same time can work as usual in the interests of ensuring the safety of the flight over the actual terrain by-passing. By consistently changing the routes from simple to complex, it will be possible to get the characteristics of the MVK and LA in the profit center mode (accuracy, stability and controllability, operation of safety equipment, etc.) before flying along real routes. The proposed approach to the creation of information support tests MWA LA has not previously been applied.

There is a method of checking the contour of low-altitude flight by means of simulation modeling given in the book: Modern information technologies in the tasks of navigation and guidance of unmanned maneuverable aircraft. / Edited by Krasilshchikov M.N., Serebryakova G.G. // M .: FIZMATLIT, 2009, p. 466-516.

However, the method given in this book only allows you to test the functionality of the algorithmic and software low-altitude flight contour.

There are many software modeling systems, flight simulators designed to study the behavior of automatic control systems in various flight modes. For example, X-Plane is an aviation simulator developed and distributed by Laminar Research.

With the help of the specified flight simulators, it is possible to check the laws of control and efficiency of software and mathematical software, but they lack the ability to estimate the MER using “virtual” test sites for effective MEL tests.

There is a method for constructing three-dimensional models of the underlying surface, described in the article by K.A. Mamrosenko, V.N. Reshetnikova. Simulation of the underlying surface in simulation systems. / Software products and systems // №4 (112), 2015

Due to the large number of special files, the model described in the above method is computationally complex and very cumbersome due to the large number of points: on large models of the underlying surface (> 3 km), it is necessary to introduce additional restrictions. It should be noted that the pictures will show objects that are on the surface of the Earth: trees, houses, the shadows of houses, airplanes and others. For some areas it is necessary to clean the images from such objects, such work is usually done manually and is very laborious. For the formation of the relief of the underlying surface, it is possible to use data obtained using the radar topographic survey Shuttle radar topographic mission (SRTM). When modeling the landscape using SRTM data, incorrect terrain may be displayed. For example, a coastal cliff can be modeled as a gentle coast. This is possible, for example, in the case of insufficient resolution of the source data, which leads to interpolation of the data.

The purpose of the invention is to reduce material costs and time for testing the contour of low-altitude flight of the aircraft.

элементарное звено №3 - максимальный передний склон с заданным углом

элементарное звено №4 - минимальный передний склон с This goal is achieved due to the fact that according to the claimed method for evaluating a low-altitude control loop of an aircraft (LA) containing a simulation of a virtual terrain map, using a dynamic model of the test aircraft, flying along a given route, additionally decomposes a given route of mountain relief into N (here 16) elementary links are given, by which are meant the elements of the underlying relief located on the flight trajectory, with the characteristics specified in tactics nical reference (. Figs 1-16), e.g., aromatic unit №1 - plain aromatic unit №2 - Front minimum slope with a predetermined angle

elementary link number 3 - the maximum front slope with a given angle

elementary unit number 4 - the minimum front slope with

exit to the plain, elementary link number 5 - the maximum front slope with access to the plain, elementary link number 6 - the maximum front slope with a straight rear slope, elementary link number 7 - the minimum front slope with the maximum rear slope, elementary link number 8 - the maximum front slope with a minimum rear slope, elementary link number 9 - two consecutively standing obstacles, elementary link number 10 - "land-sea", elementary link number 11 - "sea-land", elementary link number 12 - two consecutive obstacles tions with a height of vertices 1 / 2Н _rel and Н _rel , elementary link №13 - two consecutive obstacles with a height of vertices H _rel and 1 / 2N _rel , elementary link №14 - two successive obstacles at a distance L from each other, an elementary link No. 15 - two consecutive obstacles with a height of vertices 1 / 2Н _rel and H _rel at a distance L from each other, elementary link No. 16 - two consecutive obstacles with a height of vertices H _rel and 1 / 2H _rel at a distance L from each other, using the links in the correct order, form the mountain relief with the parameters specified in the TTZ on the aircraft (LA), the developed route is tied to the geographical coordinates (φ, λ) defined by the navigation system on board the LA, for each elementary link the area f (H, V _etc. ) is determined separately performing a profit center, the totality of such areas actually forms the general area of the possibility of performing a profit center over a given terrain, knowing that, using modern digital computers (digital computers (ground and airborne), it is possible it aircraft flight route to MVP mode. As a result, the evaluation of all the proposed links for each link forms the high-altitude region of a specific aircraft, providing unconditional overflight of obstacles. The set of links, located in any order, forms a mountainous relief, which the aircraft must fly around at a given depth of the profit center. Perform a profit center over each link consistently throughout the permitted high-altitude range of the profit center. The flight to the evaluation of the MVK is performed in a flat terrain in the absence of any dangerous obstacles. Offsets Δφ, Δλ are added to the geographic coordinates (φ, λ) determined by the navigation system onboard the aircraft so that the position of the aircraft relative to the digital map of the real terrain (CKM) corresponds to the position of the aircraft on the test track of the virtual terrain (slightly intersected, hilly, mountainous chain of mountains, water surface, etc.). By consistently changing the routes from simple to complex, it will be possible to get the characteristics of the MVK and LA in the profit center mode before flying on real routes.

The principle of operation of the method for evaluating a low-altitude control loop of an aircraft is illustrated by drawings: FIG. 1 - elementary unit №1 - plain, FIG. 2 - elementary link number 2 - the minimum front slope, figure 3 - elementary link number 3 - the maximum front slope, figure 4 - elementary link number 4 - the minimum front slope with access to the plain, figure 5 - elementary link number 5 - maximum front slope with access to the plain; FIG. 6 — elementary unit No. 6 — maximum front slope with a straight rear slope; FIG. 7 — elementary unit No. 7 — minimal front slope with a maximum rear slope; FIG. 8 — elementary unit No. 8 — maximum front slope with a minimum rear slope; FIG. 9 - elementary link number 9 - two consecutive identical obstacles, FIG. 10 - elementary unit No. 10 “land-sea”; FIG. 11 — elementary unit No. 11 “sea-land”; FIG. 12 — elementary element No. 12 — two successively standing obstacles with the height of peaks 1 / 2H _rel and H _rel ; FIG. 13 - elementary link number 13 - two consecutive obstacles with the height of the vertices H _re and 1 / 2H _rel ; FIG. 14 — elementary unit No. 14 — two successively standing obstacles at a distance L from each other; FIG. 15 - elementary element No. 15 - two consecutive obstacles with the height of the peaks 1 / 2H _rel and H _rel at a distance L from each other, FIG. 16 — elementary unit No. 16 — two successively standing obstacles with the height of the vertices H _rel and 1 / 2H _rel at a distance L from each other, FIG. 17 - Flight route when there are no obstacles on the path exceeding the requirements of the TTZ; FIG. 18 - Flight route in the presence of obstacles on the direct path of the AB that exceed the requirements of the TTZ; FIG. 19 - Roll, depending on the rate of change of course at a constant flight speed of the aircraft, Fig. 20 - Maximum loss of height depending on the roll at a constant speed of flight of the aircraft.

The “link” method for the assessment of low-altitude flight (FPM) involves the construction of a flight trajectory over the terrain in the form of an arbitrary sequence of elementary links — terrain sections with parameters specified in the TTZ on the aircraft. For each elementary level, the region f (H, Vs, _etc. ) of the possible performance of the profit center is determined separately. The combination of such areas actually forms the general area of the possibility of performing a profit center over a given terrain, knowing that, using modern digital computers (ground-based and airborne), it is possible to pave the flight path of the aircraft in profit center mode.

The flight route can be a straight line from point A to point B (Fig. 17), if there are no obstacles on the flight path that the aircraft cannot fly in straight flight with heels no more than 7 °, or a broken line (Fig. 18), there are such obstacles (the characteristics of the obstacles exceed the requirements specified in the TTZ).

In the second case (Fig. 18), the route is built in such a way that, as a result of a course change, the characteristics of the aircraft, determined by the “link” method, allow one to overcome the obstacle with a given accuracy, and the raid on the obstacle is carried out with a roll no more than 7 °. Varying the parameters n _{at min} , n _{at max} , V _pp , determining the size of the docking distance L _st , it is possible to build several routes of the aircraft from point A to point B. At the same time, the radius of the safe maneuver zone

for changing course (d = f (V _p , γ _la , ΔΖ)) must ensure completion of the maneuver at a distance of at least L _st to the next obstacle with access to horizontal flight (GP), corresponding to a roll γ <7 °, at a given flight level (Fig. 18).

When constructing a route, the profit center must select the safe height of the flight level of the profit center and determine the maximum possible deviation of the aircraft from the line of the given route during the flight between two adjacent waypoints of the profit center.

Consider the step of determining the safe height of the echelon.

When flying in profit center mode with banks of not more than 7 ° (in fact, straight-line flight) with the automatic control of the control unit (OUT) turned on, the height of the safe echelon will consist of the following components:

H_{ash bp} = N_{ass ash} + ΔΗ_open + ΔΗ_prg,                    (one)

Where:

Η _{esh bp} - safe altitude when performing a profit center;

H _{ash ass} - given the height of the profit center;

ΔΗ _TCI - clearance failure IAC elements (defined during Metal mining failsafe circuit IAC);

ΔΗ _prgr - altitude reserve, due to the error of the height measurement sensor used (according to the evaluation results in flight tests).

The true flight altitude of the aircraft will be determined by the value of the safe height of the echelon and the height of the underlying terrain:

N _East = N _{esh bp} + N _rlf , (2)

A change in course when performing a profit center leads to the need to create banks of more than 7 °, which in turn allows for loss of height. This fact must be taken into account when determining the safe height of the profit center. In this case, in the ratio (1) the component is added, due to the loss of height due to the presence of roll.

H_{ash bp} = N_bum ash + ΔΗ_pogr + ΔΠ_open + ΔΗγ, (3)

where ΔΗγ - loss of height due to the presence of roll.

The value of ΔΗγ is actually a value that depends on the size of the created roll, the instrument speed of the aircraft and its aerodynamic characteristics, so the parameter can only be determined experimentally.

To determine this parameter, it is advisable to construct the dependencies shown in FIG. 19 and FIG. 20, which can subsequently be used in the calculation in a digital computer.

Accurate maintenance of an aircraft line of a given path (LZP) is also one of the factors for safe performance of the profit center. A possible deviation of an aircraft from an LZP is made up of several components that are determined by the accuracy of the used sensor of the information of the navigation system, the accuracy of the digital map of the area, the accuracy of the automatic control system for maintaining a given trajectory, as well as the necessary margin in case of failure of the EAC. In general:

ΔΖ = ΔΖ _Hc + ΔΖ _MSC + ΔΖ _SAU + ΔΖ _OTC (4)

In this case, the value ΔΖ forms the concept of a safe alignment for performing a profit center.

The flight is carried out in the mode of keeping the set course, that is, with rolls of no more than 7 ° (corresponds to the mode of stabilization of the set course in the automatic control mode “Stabilization of Set Angles”). The construction of elementary links is ensured by means of an on-board computer above the flat surface, which ensures complete safety of the assessment over the entire operating range of the profit center, including checking the circuit fail-safe in real flight. The following typical elementary units (Fig. 1-16) with parameters are subject to assessment:

N _ash - the height of the specified level in the profit center;

Θ _{ps min} - the minimum angle of the front slope;

Θ _{ps max} - the maximum angle of the front slope;

Θ _{3 min} - the minimum angle of the rear slope;

Θ _{zs max} - the maximum angle of the rear slope;

N _rel - height of the relief;

L _st - docking distance.

As a result of the evaluation of all the proposed links for each link, the high-altitude region of a specific aircraft is formed, providing an unconditional overflight of the obstacle. The set of links, located in any order, forms a mountainous relief, which the aircraft is able to fly around at a given depth of the profit center.

The advantage of the “link” assessment method is low cost, flight safety, completeness of the evaluation of the characteristics of the profit center, the ability to assess the fail-safe safety of the MVK in flight, the ability to create a complete adequate relief-environment-LA model that will provide accurate simulation of the profit center before performing the flight over the real mountain relief , the ability to create a data bank to automate the selection and mathematical calculation of the route of the profit center using ground and airborne computing resources, which in turn will allow To protect the safety of the profit center over the selected mountainous terrain.

The technical result of the use of "virtual" polygons are: the use of standard on-board information systems instead of models; the impact on LA of real disturbances (atmospheric turbulence, the proximity of the “earth's surface”, etc.); moreover, it is sufficient to simulate the disturbance; no need to develop a terrain model and an abnormal digital computer on board the aircraft; the possibility of training and training of flight personnel in real flights; evaluation by the flight personnel of the ERK ergonomics; the possibility of evaluating the operation of safety equipment and the dynamics of the discharge from a dangerous height H _op if there is an adequate margin in height; the possibility of using the obtained results after testing the relief ergodicity hypothesis for statistical processing of test materials; reduction in the number of flights required for the evaluation of the IMC in

mountainous conditions; an increase in the test flight time and a reduction in fuel consumption (no need to fly to the mountain range and back — flights are carried out in plain conditions) and, as a result, a decrease in the total number of test flights for the evaluation of the ERM.

Claims (1)

The method for evaluating the low-altitude control circuit of an aircraft (LA), which includes modeling a virtual terrain map, using a dynamic model of the test aircraft, flying along a given route, characterized in that it additionally decomposes the specified route of the mountain relief into N elementary links, which are understood underlying terrain elements located on the flight trajectory, with characteristics specified in the tactical-technical task, for example, elementary element No. 1 - plain, el elementary link number 2 - the minimum front slope with a given angle

elementary link number 3 - the maximum front slope with a given angle

elementary link number 4 - the minimum front slope with access to the plain, elementary link number 5 - the maximum front slope with access to the plain, elementary link number 6 - the maximum front slope with a straight rear slope, elementary link number 7 - the minimum front slope with the maximum rear slope, elementary link number 8 - the maximum front slope with a minimum rear slope, elementary link number 9 - two consecutive identical obstacles, elementary link number 10 - "land-sea", elementary link number 11 - "sea-land", element ary link number 12 - two consecutive obstacles with a height of peaks 1 / 2Н _rel and Н _rel , elementary link number 13 - two successive obstacles with a height of vertices H _rel and 1 / 2H _rela , elementary link number 14 - two consecutive obstacles on distance L from each other, elementary element No. 15 - two consecutive obstacles with a height of peaks 1 / 2H _rel and H _rel at a distance L from each other, elementary link No. 16 - two consecutive obstacles with a height of vertices H _rel and 1 / 2H _rel at a distance L from each other by The mountain links in the required order form a mountain relief with the parameters specified by the requirements specification (TTZ) on the aircraft, the developed route is tied to the geographical coordinates (ϕ, λ, H) defined by the navigation system on board the aircraft, for each elementary link is determined separately area f (H, V _etc.) of a possible implementation of a low-altitude flight (IMP), a plurality of such regions actually forms a common area on the possibility of the IMP specify terrain, knowing that, with Utilized Modern digital computers (ground and airborne), it is possible to pave the flight route of the aircraft in the profit center mode, as a result of evaluating all the proposed links for each link form the high-altitude region of a particular aircraft, providing an unconditional overflight of obstacles consisting of a set of links, located in any order, form a mountainous relief, which the aircraft must fly around at a given height of the flight level of the profit center, perform a profit center over each link successively throughout the entire allowed altitude-velocity range of the profit center, flight on the evaluation of low-altitude contour (MSC) is performed in a flat terrain, in the absence of any dangerous obstacles, to the geographical coordinates (ϕ, λ, H), determined by the navigation system on board the aircraft, are added offsets Δϕ, Δλ, ΔН so that The position of the aircraft relative to the digital map of the real terrain (CMC) corresponded to the position of the aircraft on the test track of the virtual terrain (weakly intersected, hilly, mountainous terrain, chain of mountains, water surface, etc.), sequentially changing the paths from simple to complex, they get the characteristics of MVK LA in the mode of profit center before flying on real routes.

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