RU2301456C1 - Method of prevention of collision of flying vehicle with ground and device functioning on basis of this method - Google Patents

Abstract

FIELD: systems for ensuring safety flights for various flying vehicles.

SUBSTANCE: proposed method includes determination of flying vehicle position by means of navigational system and parameters of present dynamic state, calculation of predicted trajectory, comparison of predicted trajectory with relief of terrain, determination of dangerous relief and giving warning on danger. Prior to comparison of predicted trajectory with relief of terrain, minimum permissible radii of turn are continuously calculated on basis of parameters of present dynamic state after which radii of turn are predicted during determination of dangerous relief and predicted trajectory is compared with relief of terrain by scanning the space in the corridor safe for the said trajectory. Boundary of safe corridor is determined on the assumption of possibility of turning the flying vehicle to reciprocal heading in accordance with predicted magnitudes of minimum permissible radii of turn. Dangerous relief is determined on basis of comparison of predicted trajectory with relief of terrain. Device functioning on basis of this method is provided with calculators of minimum permissible radii of turn at present moment and predicted for preset time, safe corridor former and comparator scanning unit for comparison of safe corridor with relief of terrain.

EFFECT: enhanced safety of navigation.

4 cl, 5 dwg

Description

The invention relates to the field of flight safety and, in particular, to methods for determining safe trajectories of aircraft (LA) over an area with complex terrain and can be used on all types of aircraft.

Known methods for preventing a collision of an aircraft with a terrain in which the location of the aircraft using a navigation system is determined, the parameters of the current dynamic state are determined, the mentioned parameters of the current dynamic state are extrapolated to a predetermined time interval, the predicted trajectory is calculated, it is compared with the terrain and warned of danger collisions [1-5].

Known methods of collision avoidance, providing a way out of a dangerous situation by assessing the possibility of vertical maneuver [6], and with a negative result of such an assessment - by determining the direction of a possible side turn [7].

The disadvantage of all the above methods is due to the lack of reliability of preventing collisions of aircraft with the terrain. This drawback is always present due to the fact that the proximity of a dangerous terrain is determined strictly according to the course of the aircraft in the range of the location of the aircraft. However, there may be situations when, upon detection of a dangerous terrain along the course and the inability to get around the dangerous terrain by climbing, the aircraft will be forced to make a U-turn. In this case, it is necessary to provide a safe space for turning in one direction or another. As is known [8–10], the permissible turning radius is a variable that depends on the dynamic parameters of the aircraft at the moment.

However, if the dangerous terrain has, for example, the form of a gorge, then when evaluating a lateral turn in any direction [7], an alarm may be generated. Consequently, in the case of a negative assessment of the possibility of vertical maneuver, a side turn will also be impossible and an accident is inevitable.

Thus, the aforementioned drawback is inherent in all known methods of preventing a collision of an aircraft with a terrain.

In this regard, for the prototype of the claimed invention, the method according to the patent [5] is selected, in which the most general and characteristic features of the aircraft collision avoidance warning system with the terrain are implemented, namely the following sequence of actions: determining the location of the aircraft using the navigation system, determining the parameters of the current dynamic aircraft status, extrapolating parameters to a given time interval, calculating the predicted trajectory, comparing it with the terrain, warning of danger awn collision.

The known prototype device that implements this method includes a navigation system, an obstacle detector, an alarm device, a video generator and a display at its output, while the obstacle detector includes a current dynamic state parameter calculator, a coordinate determiner, a predicted path calculator and a comparator, the output of the navigation system is connected to the inputs of the calculator of the parameters of the current dynamic state and the determinant of coordinates, the outputs of which are respectively connected to the second and second inputs of the predicted trajectory calculator, the third input of which is connected to the aeronautical information database, the first and second inputs of the comparator are connected respectively to the control unit and the terrain database, the first and second outputs of the comparator are respectively connected to the input of the alarm device and the first input of the video generator, the second and the third inputs of which are respectively connected to the base of aeronautical information and the output of the determinant of coordinates, and the output of the calculator of the predicted trajectory connected to the third input of the comparator.

The task of the invention is to increase flight safety by determining the dangerous terrain, taking into account the possibility of turning the aircraft to the opposite course (to the right or left of the predicted trajectory).

The problem is solved as follows.

The essence of the proposed method for preventing a collision between an aircraft and a terrain is that it determines the location of the aircraft using the navigation system, determines the parameters of the current dynamic state, calculates the predicted trajectory, determines the dangerous terrain and warns of the presence of danger, while continuously before determining the dangerous topography calculated on the basis of the parameters of the current dynamic state the value of the minimum allowable radius turn (to the right and left), then predict the value of the said turn radius for the time of determining the dangerous terrain, and then by scanning the space with the predicted path, form a safe corridor, the boundaries of which are determined based on the possibility of the aircraft turning to the opposite course in accordance with the predicted value of the minimum allowable turning radii, and determine the dangerous terrain based on a comparison of the aforementioned safe corridor with the terrain.

It is proposed that the boundaries of the safe corridor be determined by scanning the space with the line of the predicted trajectory to the left and right of the mentioned trajectory, while the width of the safe corridor is determined by the formula:

Where

L is the width of the safe corridor;

R _ave.p. - the predicted minimum permissible radius of the right turn;

R _sp.l. - the predicted minimum allowable radius of the left turn;

l ₁ - the maximum error in determining the location of the aircraft;

l ₂ - the minimum safe lateral distance of the aircraft from the terrain.

A device that operates on the basis of the proposed method. This device for preventing a collision between an aircraft and a terrain contains a navigation system, an obstacle detector, an alarm device, a video generator and a display at its output, while the obstacle detector includes a current dynamic state parameter calculator, a coordinate finder, a predicted path calculator and a comparator, and the navigation system output is connected to the inputs of the calculator of the parameters of the current dynamic state and the determinant of coordinates, the outputs of which respectively connected to the first and second inputs of the predicted trajectory calculator, the third input of which is connected to the aeronautical information database, the first and second inputs of the comparator are connected respectively to the control unit and the terrain database, the first and second outputs of the comparator are respectively connected to the input of the alarm device and the first input of the video generator , the second and third inputs of which are respectively connected to the base of aeronautical information and the output of the determinant of coordinates, while a litel of the minimum permissible turning radii, a calculator of predicted minimum permissible turning radii, a shaper of the safe corridor and a scanning unit of the comparator, while the input of the calculator of the minimum permissible turning radii is connected to the output of the calculator of the parameters of the current dynamic state, and its output is connected to the first input of the shaper of the safe corridor, the second the input of which is connected to the output of the calculator of the predicted minimum permissible turning radii, and its third input with is dined with the output of the predicted path calculator made with an additional output that is connected to the input of the predicted minimum permissible turning radius calculator, the output of the safe corridor shaper connected to the third input of the comparator and the input of the scanning unit of the comparator, the output of which is connected to the fourth input of the comparator, and the fourth input the video generator is connected to the output of the calculator of the predicted trajectory.

A device variant is proposed with the introduction of a memory node of a trajectory, the input of which is connected to the output of the coordinate determinant, and the output is connected to the fifth input of the video generator.

The operation of the method is illustrated using figures 1-4. The operation of the device is illustrated using figure 5.

Figure 1 - sequence diagram for implementing the proposed method.

Figure 2 - planned (A) and profile (B) projection of the predicted trajectory and a safe spatial corridor.

Figure 3 - scheme for constructing a planned projection of the predicted trajectory and a safe spatial corridor.

Figure 4 - scheme for constructing a profile projection of the predicted trajectory and a safe spatial corridor.

5 is a block diagram of the inventive device.

The inventive method is implemented by the following sequence of actions (see figure 1).

Similarly to the prototype method [5], using the navigation system, determine the location of the aircraft 1, determine the parameters of the current dynamic state of the aircraft (ground speed - W _p , vertical speed - W _y , track angle - PU, turn speed - ω _y , etc. ) 2, by which the location of the aircraft is extrapolated for a given time interval (T _p ) and the calculation of the predicted trajectory 3. However, further, unlike the prototype, the calculation is carried out continuously before determining the dangerous terrain minimally acceptable x turning radii (to the right and left of the predicted trajectory) based on the parameters of the dynamic state 4, then calculating the predicted (at the time of determining the dangerous terrain) turning radii 5 based on the calculated predicted dynamic parameters of the aircraft, then determine the boundary of the safe spatial corridor (MIC) 6, within which the predicted trajectory should be located.

The BOD boundaries are determined based on the possibility of the aircraft turning to the opposite course in accordance with the projected minimum acceptable turning radii. In this case, the military-industrial complex is compared with the terrain 7 (within the limits of the formed sample from the relief database 8) by scanning the space within the BOD. In case of coincidence of part of the terrain with BOD 9, a notification is generated about the presence of danger 10.

BOD in figa, B is a spatial region associated directly with the current location of the aircraft 11 and determined (in shape and orientation in space) predicted path 12, the minimum allowable radii of the rotation circles to the right 13 and left 14, and predicted (for a given time interval) by the minimum allowable radii of the circle of a turn to the right 15 and left 16. In addition, the BOD is formed on the basis of the maximum error in determining the location of the aircraft l ₁ and the minimum safe side races the position of the aircraft from the terrain l ₂ , and is also determined by the motion parameters (W _p , W _y , PU, ω _y ), the minimum permissible height N _ppm , an additional reserve of height ΔН, determined from the condition of minimizing the probability of pseudo-positive alerts. The value of N _MD , as is known [6], depends on the stage of the flight (cruise flight, flight in the airport area, approach) and flight mode (horizontal flight, descent, climb). The sum (N _md + ΔН) is the distance 17, by which the lower part of the BOD boundary 18 is separated from the predicted trajectory, and the sum of the quantities (l ₁ + l ₂ ) 19 is the minimum distance from the BOD border to the U-circles as with the minimum allowable radii, and with predicted minimum allowable radii.

Recalculation of the configuration of the boundaries of the BOD 18 is carried out at the pace necessary to update the information, and thus, the BOD with a width of 20 is formed adapted to the current dynamic state of the aircraft, to the stage and mode of flight. Such a technique greatly facilitates the crew's decision-making task in this situation, since it allows us to assess the degree of danger of approaching the terrain before a dangerous situation occurs and does not require a preventive view of the terrain display, i.e. reduces the psychological burden of the crew. Thus, it is possible to completely avoid creating a dangerous situation on board by timely maneuvering based on the generated alarm about a potentially dangerous terrain.

The synthesis of the profile projection of the relief (21 in FIG. 2B and FIG. 4) is carried out by selecting the maximum heights of the relief elements presented on the planned projection within the boundaries of the information scanning area of the relief elements (22 in FIG. 2A and FIG. 3). To form a profile projection, scanning is performed within the rows (23 in FIG. 3) of the information scanning area.

The configuration of the information scanning area with borders 22 for forming the profile projection of the relief 21, shown in FIGS. 2B and 4, respectively, is selected from the calculation of ensuring the display on the profile projection of the relief contour located within the space of the BOD extended in the direction of the forecast flight of the aircraft and the direction opposite to the current track angle 24 (see figure 3).

The terrain maximally distant from the aircraft displayed on the profile projection is determined by the vertical scale of the range of the planned projection, which can be seen from a comparison of the location of the scale grids of the range 25 on the plan and profile projections (see figure 3 and figure 4). The excess of the dangerous terrain over the aircraft allows us to evaluate the large-scale grid 26 (see figure 4).

As shown in figure 3 and figure 4, the surface bounding the generated BOD, facing the terrain located in the direction of the forecast flight, aligned at the starting point with the aircraft, expands (or narrows) in the direction of flight and has a leading edge away from the aircraft, corresponding to the position of the u-turn circle maximally distant from the aircraft (in Fig. 2B and Fig. 4, the left circle is maximally distant from the aircraft) with a predicted ground speed W _pp . The extension (narrowing) of the military-industrial complex in the direction of flight in the absence of maneuvering the aircraft at the heading is symmetrical in accordance with the predicted increase (decrease) in the current ground speed W _p . If there is a non-zero reversal rate ω _{у, the} BOD curvature is predicted in the direction of the reversal being performed.

The boundary surface of the BOD (18 in figure 2 and figure 3) is formed by five consecutive surfaces (17, 27-30 in figure 4). The first four consecutive surfaces form part of the boundary surface, signaling the danger of aircraft dropping to a height exceeding the minimum permissible flight altitude N _md for an additional reserve of altitude ΔН. This part of the boundary surface is located below the predicted trajectory 12 by the value of N _MD + ΔН, where the value of the additional bias ΔН> 0 and is determined from the condition of minimizing the probability of the formation of a pseudo-positive signaling. The fifth face 30 of the boundary surface 18 is located vertically upward and forms part of the boundary surface, warning of the relief with a dangerous excess in the direction of flight. At the same time, a terrain with dangerous excess is understood to mean a terrain from which it is impossible to get away at the minimum permissible height above it, performing a turn with a climb, while observing the requirements for permissible vertical and lateral overloads. The first facet 17 is vertical, its width is determined by the accuracy of estimating the coordinates of the aircraft (2l ₁ ), the safe distance from the terrain (2l ₂ ), the current value of the minimum permissible radii of the right (2R _sp. ) And left (2R _sp . and the height is equal to N _md + ΔН, i.e., being a function of N _md , it corresponds to the stage and flight mode to which the BOD is adapted. The lengths of the horizontal projections of the second 27 and third 28 surfaces (L2 and L3, respectively) are determined by the time necessary to perform the aircraft’s vertical maneuver with the predicted avoidance of the hazardous terrain (taking into account the permissible vertical overload), determined by the predicted value of the ground speed W _pp . The inclination of the second face 27 relative to the horizon is equal to the trajectory angle Θ 31, the tangent of which is equal to the ratio of the current values of vertical (W _y ) and ground (W _p ) speeds. The third surface 28 is conical or (in the absence of a forecast of lateral maneuvering) cylindrical and the length of its horizontal projection L3 is determined by the condition of permissible vertical overload for the predicted flight of the aircraft along the circular arc 32 lying in the vertical plane. The fourth surface 29 with a horizontal projection length L4 rises below the permissible trajectory angle of climb equal to Θ _additional 33, until reaching the distance from the aircraft controlled by the BOD, determined by the predicted flight time T _p s s the rate that varies from the current value of W _p to the predicted W _pp , as well as determined by the position of the most remote circle of a turn with predicted minimum allowable radii (R _a.s. and R _a.s. ), values l ₁ and l ₂ and limited by a vertical fifth surface 30. If during the flight the relief elements determined by the formed sample from the BDR, according to the results of the calculations performed, are located inside the BOD (see figure 2), a notification alarm is generated.

The calculation of the minimum allowable aircraft turning radii required for the formation of the BOD is made in accordance with the equations of motion, the complexity of which can vary significantly, depending on the phase of the flight. In the general case (without taking into account the Earth’s orbital motion around the Sun, Earth’s daily motion and fuel burnup), the minimum allowable radii are determined numerically by solving the system of aircraft motion equations given below [8].

The equation of forces in the trajectory coordinate system:

Where

m is the mass of the aircraft;

- вектор скорости ЛА в земной СК;

is the aircraft velocity vector in the Earth's SC;

t is the time;

V _kx is the projection of the earth's velocity on the X axis by the SC trajectory;

Θ is the angle of inclination of the trajectory;

Ψ - track angle;

обозначает представление i-ого вектора (тяги ЛА

, аэродинамической силы

, силы тяжести

, результирующей силы реакции шасси

) в i-ой системе координат (СК) (св - связанная СК, т - траекторная СК, з - земная СК, ск - скоростная СК);symbol

denotes the representation of the i-th vector (aircraft thrust

aerodynamic force

gravity

resulting chassis reaction force

) in the i-th coordinate system (SK) (sv - connected SK, t - trajectory SK, s - terrestrial SK, sk - speed SK);

обозначает переходную матрицу коэффициентов из одной СК в другую (в данном случае из связанной в земную).symbol

denotes a transition matrix of coefficients from one SC to another (in this case, from connected to the earth).

The equation of angular momentum relative to the center of mass of the aircraft:

Where

- тензор инерции (симметричная матрица из моментов инерции ЛА относительно осей связанной системы координат, в которой для самолетов, имеющих вертикальную плоскость симметрии, I_xz=I_yz=0);

- inertia tensor (a symmetric matrix of the moments of inertia of the aircraft relative to the axes of the associated coordinate system, in which for airplanes having a vertical plane of symmetry, I _xz = I _yz = 0);

- вектор угловой скорости вращения самолета, а матрица

получается из

транспонированием;

is the vector of the angular velocity of rotation of the aircraft, and the matrix

obtained from

transpose;

- момент тяги ЛА;

- aircraft traction moment;

- аэродинамический момент;

- aerodynamic moment;

- плечо результирующей силы реакции шасси;

- the shoulder of the resulting reaction force of the chassis;

- плечо силы тяжести.

- the shoulder of gravity.

The equations of kinematic relationships of linear velocities:

Where

x _g , y _g , z _g - coordinates of the aircraft in the Earth's SC;

L and H - range and altitude.

The equations of kinematic relationships of angular velocities:

Where

ω _x1 , ω _y1 , ω _z1 - projection of the angular velocity of rotation of the aircraft on the axis of the associated coordinate system;

γ is the angle of heel;

ψ is the yaw angle;

ϑ - pitch angle.

General assumptions (symmetrical thrust of the engine, motionless atmosphere) and various assumptions that are possible in trajectory tasks in most areas of the flight (coordinated flight in a vertical plane, horizontal flight in a straight line, horizontal steady flight, straight climb or decrease, climb or decrease at a constant speed, pre-landing descent along the glide path, horizontal flight with slip without roll, horizontal flight with roll without slip) the system (2-5) in each of these cases a substantially simpler form [9].

Using simplified equations to determine the minimum permissible turning radii and calculating the predicted trajectory allows, if necessary, to reduce computational costs and increase the speed and reliability of the calculations.

So the equations of steady curvilinear flight in a coupled coordinate system, if we consider the angular velocities small and neglect their products, can be written (neglecting the curvature of the earth's surface) in the form:

Where

β is the slip angle;

δ _n - the angle of deviation of the rudder;

δ _e - the angle of deviation of the ailerons;

- безразмерные проекции угловой скорости ЛА на оси связанной СК;

- dimensionless projections of the angular velocity of the aircraft on the axis of the associated SC;

- частная производная коэффициента аэродинамического момента крена, обусловленная аэродинамическим параметром (в данном случае скольжением);

- the partial derivative of the coefficient of aerodynamic moment of the roll, due to the aerodynamic parameter (in this case, slip);

- частная производная коэффициента аэродинамического момента рысканья, обусловленная аэродинамическим параметром (в данном случае скольжением);

- the partial derivative of the coefficient of the aerodynamic moment of yaw, due to the aerodynamic parameter (in this case, slip);

- частная производная коэффициента аэродинамической боковой силы, обусловленной аэродинамическим параметром (в данном случае скольжением);

is the partial derivative of the aerodynamic lateral force coefficient due to the aerodynamic parameter (in this case, slip);

с _у - coefficient of aerodynamic normal force;

ρ is the air density;

S is the area of the equivalent wing;

V is the flow velocity;

α is the angle of attack;

l is the wingspan.

For small pitch angles, expressions (5) take the form:

When performing in the horizontal plane of the correct turn (when the slip angle is zero), expressions (10) will take the form:

Where

b _a - the average aerodynamic chord of the wing.

Expressions (11) determine the components of the angular velocity along the axes of the coordinate system associated with the aircraft; using these expressions you can find the full angular velocity of the aircraft with the correct turn. Moving from dimensionless angular velocities to dimensional, squaring the components and adding these squares, we obtain the square of the total angular velocity and then the total angular velocity. Thus, we find:

where g is the acceleration of gravity.

, получаем еще более простое выражение:Assuming forces acting on the aircraft that are independent of the position of the rudders

, we get an even simpler expression:

Considering that V / R = ω, we obtain, taking into account the above assumptions, the simplest expression for calculating the radius of a regular bend R, performed in the horizontal plane:

In the general case, the radii of curvature of the trajectories of the right and left turns are different. For example, taking into account the asymmetry of the aircraft, which occurs when one of the engines fails. When performing a U-turn in wind conditions with a constant roll, the trajectory of the right turn and the left turn are not circles, which further complicates the calculation of the BOD boundaries.

If in the case considered in expression (14) to use the maximum allowable (for reasons of permissible lateral overload) roll γ _add. then using the current value of speed V it is possible to calculate the current minimum permissible turning radius, and using the predicted speed value - the predicted minimum permissible turning radius.

Thus, the above method and its options allow the crew to adequately assess the degree of danger of the terrain and make the right decision about the need and nature of maneuvering before a dangerous situation occurs.

One embodiment of a device that implements the claimed method is a device whose block diagram is shown in FIG.

In Fig. 5, a collision avoidance device of an aircraft with a terrain contains a navigation system 1, an obstacle detector 2, an alarm device 3, a video generator 4 and a display 5 at its output, while the obstacle detector 2 includes a calculator of the parameters of the current dynamic state 6, coordinate identifier 7 , the calculator of the predicted path 8 and the comparator 9, the output of the navigation system 1 is connected to the inputs of the calculator of the parameters of the current dynamic state 6 and the determinant of coordinates 7, the outputs of which are respectively connected to the first and second inputs of the calculator of the predicted trajectory 8, the third input of which is connected to the database of aeronautical information 10, the first and second inputs of the comparator 9 are connected respectively to the control unit 11 and the terrain database 12, the first and second outputs of the comparator are respectively connected to the input of the alarm device 3 and the first input of the video generator 4, the second and third inputs of which are respectively connected to the base of aeronautical information 10 and the output of the determinant ordinates 7.

In contrast to the prototype device, the following were introduced: a calculator of minimum permissible turning radii 13, a calculator of predicted minimum permissible turning radii 14, a shaper of a safe spatial corridor 15 and a scanning unit of the comparator 16, while the input of the calculator of the minimum permissible turning radii 13 is connected to the output of the calculator of the parameters of the current dynamic state 6, and its output is connected to the first input of the shaper of the safe corridor 15, the second input of which is connected to the output of the calculator of the predicted minimum permissible turning radii 14, and its third input is connected to the output of the calculator of the predicted trajectory 8, made with an additional output, which is connected to the input of the calculator of the predicted minimum permissible turning radii 14, and the output of the shaper of the safe spatial corridor 15 is connected to the third input of the comparator 9 and the input of the scanning node of the comparator 16, the output of which is connected to the fourth input of the comparator 9, while the fourth input of the video generator 4 is connected to the output of the comparator numerator projected path 8.

A variant of the device with the introduction of the memory node of the trajectory 17, the input of which is connected to the output of the determinant of coordinates, and the output with the fifth input of the video generator 4.

The device operates as follows: the obstacle detector 2 according to the information received at its inputs from the output of the navigation system 1, from the output of the terrain database 12, from the output of the aeronautical information base 10 performs the following functions similar to the prototype: determines the coordinates of the aircraft in the coordinate identifier 7, calculates the parameters of the current dynamic state of the aircraft in the calculator of the parameters of the current dynamic state 6, calculates the predicted trajectory in the calculator of the predicted trajectory 8.

Comparator 9 determines whether the space of the relief database elements coincides with the BOD, and not with the predicted trajectory used in the prototype for this purpose. According to the information about the parameters of the current dynamic state coming from the output of the calculator 6, in the calculator 13, respectively, the current minimum permissible turning radii are calculated. The calculator of the predicted trajectory 8 is made with an additional output from which information about the predicted parameters of the dynamic state is fed to the input of the calculator 14, where the predicted minimum permissible turning radii are calculated. According to the information coming from the outputs of the calculators 13 and 14, respectively, to the first and second inputs of the shaper of the safe corridor 15, and information about the predicted trajectory coming from the output of the calculator 8 to the third input of the same shaper, the boundaries of the safe spatial corridor are calculated in it, information about which comes from the output of the shaper 15 to the third input of the comparator 9 and to the input of the scanning node of the comparator 16. In the comparator 9 according to the results of information scanning of the relief made using the node 16, comparison is carried BOD with relief elements. If, when comparing the BOD with the relief elements, the space belonging to both the BOD and the relief database space is detected, then the comparator 9 at its outputs (and, therefore, at the outputs of the detector 2) produces signals arriving at the input of the alarm device 3, notifying about the danger , and the first input of the video generator 4 for subsequent display on the display 5 of the predicted trajectory and texts of notifications about the dangerous terrain, while the second and third inputs of the video generator in the same way as in the prototype receive inf Formation from the exit of BAI 10 about aerodromes and from the output of the coordinate determinant 7 about the current coordinates of the aircraft.

For the crew to analyze the current dynamic capabilities of the aircraft to perform maneuvering, it is useful to display on the display 5 a portion of the trajectory traversed, limited by the selected screen scale, for which an additional memory unit is entered into the coordinates of the trajectory 17, from the output of which information about the stored coordinates of the trajectory is transmitted through a video generator 4 to display 5.

The signals received at the input of the comparator 9 from the output of the control unit 11, allow you to disable the alarm.

Thus, the above method and a device based on it allow the crew to adequately assess the degree of danger of the terrain and make the right decision about the need and nature of maneuvering.

The inventive method and device based on it allow you to realize new advantages of systems for preventing collisions of aircraft with the ground:

- notify of a dangerous approach to the terrain, for a time sufficient to select a maneuver of departure, including a reversal course, without exceeding permissible overloads;

- increase crew awareness of the hazardous terrain by generating notifying information about the dangerous terrain in the area of the proposed maneuvering and thereby simplify the task of deciding on the need for maneuvering and choosing the nature of the maneuver to avoid a potentially dangerous terrain;

- to simplify the crew the task of assessing the degree of danger posed by the terrain ahead, and choosing the necessary maneuver by displaying on one scale the projection of the relief, the traversed and predicted trajectory;

- reduce the crew load to prevent dangerous proximity to the terrain by timely notification of the danger of the terrain located in the area of the proposed maneuvering.

The implementation of these advantages allows to increase the reliability of the prediction of the possibility of an aircraft collision with the terrain and to expand the crew's ability to prevent dangerous proximity with the terrain by increasing the amount of information about the danger of the relative location of the aircraft and the terrain, as well as to increase the ergonomics of presenting information to the crew by displaying the combined projections of the relief passed predicted trajectories.

The proposed method and its variants are fully implemented in the device shown in Fig.5.

The blocks and devices shown in Fig. 5 are implemented using hardware and software modules built on the basis of the widely used standard devices of analog and digital computing.

To develop software that implements the necessary functions of the mentioned devices, standard programming languages (“C”, “C ++”), software and mathematical software of the firms “MICROSOFT”, “BORLAND” and well-known formulas of geodetic transformations were used [11].

Block 2, comprising blocks 6–9, and blocks 13–17, are implemented on the basis of an AMPRO integrated module with an ANALOG MICRODEVICSES processor module, operating from an ALEXANDER ELECTRIC power supply. These blocks also use interface chips from ANALOG DEVICES and precision programmable amplifiers from TEXAS INSTRU MENTS.

Block 3 is based on TEXAS INSTRUMENTS analog audio encoders and decoders, MAXIM operational amplifiers and ALTERA programmable logic integrated circuits.

Block 4 is based on the SHARP video controller, MAXIM video amplifiers and TDK high-voltage converters.

Block 5 is implemented on the basis of the SHARP liquid crystal matrix.

Blocks 10 and 12 are implemented on the basis of read-only memory devices “DiskOnChip” of the company “M-SYSTEMS”.

Block 11 is implemented on the basis of BOURNS switches, MOLEX connectors, MAXIM voltage converters.

Mathematical modeling, full-scale and flight tests of the SRPBZ system, in which the inventive method is implemented, show that the probability of emergency flight situations compared with the prototype is reduced by 30-40%.

Conducted flight tests on aircraft Tu-154, Tu-204, Tu-214, Tu-334, Yak-40, Yak-42, Il-76, Il-86, Be-200 showed the effectiveness of using the inventive device.

Thus, the claimed invention is extremely promising for use on board an aircraft in order to reduce the likelihood of flight accidents.

Information sources

1. French patent No. 2731824, cl. G08G 5/04 claimed 03/17/1995, publ. 09/20/1998

2. French patent No. 2747492, cl. G08G 5/04 claimed 04/15/1996, publ. 10/17/1997

3. French patent No. 2773609, cl. G01C 5/00, claimed 01/12/1998, publ. July 16, 1999

4. US Patent No. 5892462, cl. G08G 5/04 claimed 06/20/1997, publ. 04/06/1999

5. US patent No. 6021374, CL. G06F 163/00 claimed 10/09/1997, publ. 02/01/2000

6. Patent of Russia No. 2262746, cl. G08G 5/04 claimed 06/10/2004, publ. October 20, 2005

7. Patent of Russia No. 2271039, cl. G08G 5/04, B64D 45/04, claimed March 24, 2005, publ. 02/27/2006

8. Kublanov M.S. Aerodynamics and flight dynamics. M .: Moscow State University, 2000.

9. Ostoslavsky I.V., Strazheva I.V. Flight dynamics. Stability and controllability of aircraft. M.: Mechanical Engineering, 1965.

10. Ostoslavsky I.V., Strazheva I.V. Flight dynamics. Trajectories of aircraft. M.: Mechanical Engineering, 1969.

11. Zakatov P.S. Course of higher geodesy. M .: Nedra, 1976.

Claims (4)

1. A method for preventing a collision between an aircraft and a terrain, which determines the location of the aircraft using the navigation system, determines the parameters of the current dynamic state, calculates the predicted trajectory, determines the dangerous terrain and warns of the presence of danger, characterized in that it is continuous before determination dangerous terrain calculated on the basis of the parameters of the current dynamic state of the minimum allowable radius of turn then, the aforementioned turning radii are predicted for the time of determining the dangerous terrain, and then, by scanning the space with the predicted trajectory, a safe corridor is formed, the boundaries of which are determined based on the possibility of the aircraft turning to the opposite course in accordance with the predicted values of the minimum permissible turning radii, and determining the dangerous terrain based on a comparison of the aforementioned safe corridor with the terrain. 2. The method according to claim 1, characterized in that the boundaries of the safe corridor are determined by scanning the space with the line of the predicted trajectory to the left and right of the said trajectory, while the width of the safe corridor is determined by the formula

where L is the width of the safe corridor; R _ave.p. - the predicted minimum permissible radius of the right turn; R _sp.l. - the predicted minimum allowable radius of the left turn; l ₁ - the maximum error in determining the location of the aircraft; l ₂ - the minimum safe lateral distance of the aircraft from the terrain. 3. A collision avoidance device for an aircraft with a terrain, comprising a navigation system, an obstacle detector, an alarm device, a video generator and a display at its output, while the obstacle detector includes a current dynamic state parameter calculator, a coordinate finder, a predicted path calculator and a comparator, and a navigation output the system is connected to the inputs of the calculator of the parameters of the current dynamic state and the determinant of coordinates, the outputs of which responsibly connected to the first and second inputs of the predicted path calculator, the third input of which is connected to the aeronautical information base, the first and second inputs of the comparator are connected respectively to the control unit and the terrain database, the first and second outputs of the comparator are respectively connected to the input of the alarm device and the first input of the video generator , the second and third inputs of which are respectively connected to the base of aeronautical information and the output of the determinant of coordinates, characterized in that a calculator of the minimum permissible turning radii, a calculator of the predicted minimum permissible turning radii, a shaper of the safe corridor and a scanning unit of the comparator are introduced, while the input of the calculator of the minimum permissible turning radii is connected to the output of the calculator of the parameters of the current dynamic state, and its output is connected to the first input of the shaper of the safe corridor, the second input of which is connected to the output of the calculator of the predicted minimum permissible turning radii, and its This input is connected to the output of the predicted trajectory calculator, made with an additional output, which is connected to the input of the predicted minimum permissible turning radius calculator, while the output of the safe corridor former is connected to the third input of the comparator and the input of the scanning unit of the comparator, the output of which is connected to the fourth input of the comparator, and the fourth input of the video generator is connected to the output of the calculator of the predicted trajectory. 4. The device according to claim 3, characterized in that the memory node of the trajectory is inserted, the input of which is connected to the output of the coordinate determinant, and the output is connected to the fifth input of the video generator.

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