RU55479U1 - HELICOPTER AIR SIGNAL SYSTEM - Google Patents

Abstract

The utility model relates to devices for measuring altitude and speed parameters of a helicopter. The technical result consists in increasing the accuracy of measuring the altitude and speed parameters of the helicopter, expanding the operating ranges for the angle of attack and speed, especially in the field of low flight speeds, which allows to increase the safety of control and piloting of the helicopter, and the effectiveness of solving flight and navigation and special tasks. The helicopter air signal system contains two orthogonally located flow-through multi-channel aerometric sensors, throttle static pressure cavities and full pressure tubes are connected to pneumatic, for example, hot-wire transducers, the outputs of the electrical measurement circuits of which are connected through a multiplexer and an analog-to-digital converter to a microprocessor to determine position angles (bevel) of the rotor column of the rotor of the helicopter, which These are used in calculating the components of the airspeed vector and determining the altitude and speed parameters of a helicopter at low flight speeds.

Description

The utility model relates to devices for measuring altitude and speed parameters of a helicopter.

Known devices for measuring the altitude-speed parameters of the aircraft that implement the aerometric method of measurement. In such devices, an air pressure receiver installed in the air stream rushing onto the aircraft senses the static and total pressure of the air flow, which determine the barometric altitude, indicator (instrument) and, using information about the outside temperature, the true air speed (D. Braslavsky A. Instruments and sensors of aircraft. M: Mechanical Engineering, 1970, 392 p.) - [1]. Using receivers installed in the oncoming flow, pressure is also perceived, which determines the angular position of the true airspeed vector in a coupled velocity coordinate system — the angle of attack and slip (Petunin A.N. Methods and techniques for measuring gas flow parameters. M .: Mechanical Engineering, 1972 , 392 p.) - [2]. However, the use of such devices in a helicopter makes it possible to accurately measure the barometric altitude and airspeed only at flight speeds of more than 50 ... 70 km / h, when the flow receivers go beyond the vortex columns created by the rotor of the helicopter and when noise-tolerant perception and transformation of perceived air pressure. The range of measurement of the angles of attack and slip of these devices is also limited to ± 30 °, while for a helicopter the workers are flying back and forth, left and right, in another other direction in the yaw and pitch planes, as well as flights in the region of small and near-zero speeds, and even in hover mode.

To obtain information on altitude and speed parameters in the field of low helicopter flight speeds in known air systems

Signals (SHS) are used by several flow-through pressure receivers placed in the nose of the fuselage symmetrically relative to the longitudinal axis of the helicopter (Kozitsyn V.K., Makarov N.N., Porunov A.A., Soldatkin V.M. Analysis of the principles of constructing airborne signal systems helicopter // Aerospace Instrumentation, 2003, No. 10, C.2-13) - [3]. Experimental studies of such a SHS developed by the Voskhod MPKB showed that at flight speeds of less than 30 km / h the error in measuring the slip angle reaches about ± 2 °, and at speeds of more than 70 km / h, when the nose of the helicopter fuselage, where the flow receivers, leaves the zone of the vortex column, the error decreases to values of ± 0.4 °, acceptable for solving control and piloting problems. However, one of the main disadvantages of such a SHS and the method implemented in it is the limited measurement range by the slip angle with the value β- ± 20 ° - [1].

The known system of air signals, which allows you to get information about the parameters of the vector of the airspeed of the helicopter and at flight speeds less than 30 ... 70 km / h. The well-known SHS of a Lassie, KhM-143 and SHS-B1-type helicopter [3] contains a freely-oriented air pressure receiver, which at low flight speeds is located in the alignment of the vortex column and is oriented using a spatial weather vane in the direction of the vector the resulting airflow running onto a freely oriented receiver, which is the sum of the vector air speed due to the translational movement of the helicopter, and the vector inductive speed created by the rotor of a helicopter. In this case, the system of equations by which the components V _x , V _y , V _z of the true air velocity vector are determined , attack angles α and slip β of the helicopter have the form (Kozitsyn V.K. Algorithmic support of helicopter air signal systems based on a freely oriented pressure receiver // Izv.

Aircraft technology. 2004. No4. S.52-57) - [4]:

where i _z , i _x are the angles of inclination of the plane of the rotor disk; α _VK and β _VK are the bevel angles of the vortex column air flow relative to the axes of the coupled (speed) coordinate system.

However, as can be seen from the system of equations (1), such a system has significant errors in determining the parameters V _x , V _y , V _z , α and β of the true airspeed vector of the helicopter, especially in the low-speed region, due to the lack of accurate information in flight about the current value (about the module) of the inductive velocity vector and angles of position i _z , i _x rotor disk. Moreover, the accuracy of measuring the angles α _VK and β _{VK of the} bevel of the vortex column air flow, determined by the angular position of the freely oriented receiver relative to the axes of the speed coordinate system, also significantly affects the measurement errors of the helicopter air velocity vector parameters. Since during the operation of the system the angles α _VK and β _{VK are} determined by recording the angular position of the vector the resulting air flow of the vortex column, then due to the small weather vane moment, the presence of friction in the cardan suspension and loading of the movable system of the freely oriented receiver in the region of low flight speeds, an additional error takes place, which increases the value of the minimum operating flight speed at which the system provides a stable measurement of altitude and speed parameters of a helicopter.

The prototype is a system for measuring air signals, based on a fixed multichannel flow

airborne receiver and jet-convective (thermoamometric) measuring channels (Porunov A.A., Soldatkin V.V. Structure and algorithms of a helicopter air signal system based on a multifunctional aerometric sensor // Proceedings of the Second International Symposium "Aerospace Instrument Technologies", 17- September 20, 2002 St. Petersburg. SPbSUAPS. S.33-35) - [5].

The basis of the work of such a system of air signals is the processing of an array of primary informative pressure signals perceived by a stationary flow-through multi-channel aerometric receiver, made, for example, according to RF patent No. 2042137, IPC G 01 P 5/16, Multi-channel aerometric sensor // Porunov A.A ., Olin V.N., Zakharova N.S. - [6].

To perceive information about the parameters of the helicopter airspeed vector using two profiled disks (Fig. 1), a plane-parallel air jet is emitted in the incoming air flow in the yaw plane, the parameters of which depend on the magnitude and direction angle of the true helicopter airspeed vector in the yaw plane in the range of ± 180 °. Using an aerodynamic body located between two profiled disks with full pressure tubes mounted on it and throttle static pressure annular receivers located on the inner surfaces of the profiled disks, pressures p _i and p _c are generated, which are proportional to the true airspeed , glide angles β and attack α of the true airspeed vector V _in and the static pressure of a plane-parallel air stream, convert the pressure into electrical signals using pneumoelectric, for example, hot-wire anemometers, which determine the altitude-speed parameters of the helicopter by restoring and processing the primary

pneumatic pressure signals according to a specific algorithm - [6].

An important feature of the angular characteristics of a flow multi-channel aerometric flow receiver (AMP) is that these characteristics contain two sections: within the first, the perceived pressure p _i AMP is greater than the local static pressure p _c , and within the second, this pressure p _{i is} less than p _c .

Figure 2 shows the family of angular characteristics of a multichannel flow AMF having six identical sections for perceiving the parameters of the helicopter airspeed vector, which is built for three values of speed: V = 3 m / s, V = 15 m / s, V = 30 m / s - [5, 6]. An analysis of these graphs allows us to note that the angular characteristics of the full pressure tubes i-1 and i + 1 in the pressure range p _i <p _c have an intersection point whose angular coordinates coincide with the coordinate of the maximum angular characteristic of the full pressure tube with number i. The intersecting branches of the angular characteristics of i-1 and i + 1 tubes of full pressure have sections of sufficient length within which they can be approximated using mathematical methods that are reliably implemented by software, for example, using spline methods. These features of the angular characteristics of multichannel flow AMF are the basis for the algorithm for processing primary pneumatic pressure signals, which provide the determination of the magnitude and angle of the vector of the true airspeed of the helicopter.

Information on the magnitude and direction angle of the true airspeed vector of a helicopter is obtained by mathematical processing of primary pneumatic pressure signals according to an algorithm based on the relationship the current pressure values p _{i + 1} and p _{i of the} adjacent full pressure tubes with the angular position β of the helicopter’s true airspeed vector.

In the practical implementation of the algorithm, a dimensionless coordinate system is introduced, the abscissa of which is the dimensionless angular coordinate Θ, and the ordinate is the ratio as shown in FIG. 3.

The limits of change Θ are determined by the choice of the coordinate grid (for example, Θ _max = 3 at a grid pitch of t ₀ = 10 deg., Θ _max = 6 at t ₀ = 5 deg.). The origin of the introduced coordinate system coincides with the intersection point of adjacent branches of the angular characteristics of i + 1 and the ith full pressure tubes.

The algorithm for processing the array i of pneumatic signals (i = 0, 1, ... 5) provides for the following steps. At the first stage, the number of the i-th full pressure tube is determined, within the positive branches of which the direction of the helicopter airspeed vector is localized. For such an i-th full pressure tube, as follows from Figure 3, take the tube in which the value of the measured pressure is the largest. The number of such i-th full pressure tube determines the first approximation of the angular coordinate of the helicopter airspeed vector in accordance with the expression

It is assumed that the axis of the first tube coincides with the origin of the original coordinate system.

Then carry out a preliminary assessment of the position of the helicopter airspeed vector relative to the i-th full pressure tube. To this end, check which of the inequalities:

performed.

In the case of the first inequality, the helicopter air velocity vector is to the left of the ith full pressure tube and the parameter k for estimating the angular position of the air velocity vector relative to the axis of the ith full pressure tube takes the value k = -1. If expression (3) is satisfied, then the helicopter airspeed vector is to the right of

i-th tube and k = + 1.

At the next stage of the processing of measured pressures, the current value of the angular coordinate Θ of the helicopter airspeed vector is determined in the introduced coordinate system by solving the following equations:

where ƒ (Θ) and ƒ (-Θ) are polynomials of degree n calculated by preliminary calibration of a multichannel flow AMP and approximation of the angular characteristic of the ith full-pressure tube in the range Θ∈ [Θ _min , Θ _max ] based on the selected spline functions. Moreover, the first relation of expression (4) is used when the condition p _i-1 > p _{i + 1 is} fulfilled, and the second one when p _i-1 <p _{i + 1} . Moreover, in the used dimensionless coordinate system, the function ƒ (Θ) describes a part of the right branch of the angular characteristic of Fig. 3, and ƒ (-Θ) describes the left part of this characteristic.

Next, the angular coordinate Ψ _x of the helicopter airspeed vector in the initial (connected speed) coordinate system is defined as

where t ₀ is the grid step in the introduced coordinate system (Figure 3) Ψ _x ∈ [Θ _max -Θ _min ].

After determining the direction angle Ψ _x of the helicopter air velocity vector, the pressure value p _m corresponding to the air velocity vector module is calculated in accordance with the following relations:

The final stage of the algorithm for processing the initial array of pneumatic signals is to calculate the value of V _{in the} helicopter airspeed vector, which is determined on the basis of

preliminary calibration of the AMP according to the graph of changes in the total p _n and static p _c pressures shown in Fig.4.

Profiling the inner surfaces of the shielding disks of the multichannel flow AMF along a contour close to the Venturi profile allows not only to multiply the velocities at the location of the full pressure tubes, but also to fit into the surface of the input edges with a sufficiently large curvature forming the receiving holes (Figure 1) to determine the second coordinate of the spatial free stream, for example, the angle of attack of the helicopter. In this case, the value of the angle of attack a is determined in accordance with the relation [2]

where 2Θ ₀ is the angle of the receiving holes along the channel of the angle of attack; - the pressure perceived by the respective pressure receivers on the upper and lower disks; α is the angle of attack of the helicopter.

Thus, processing the array of primary pneumatic pressure signals of a flow multichannel aerometric receiver according to the algorithm proposed in [6] allows one to significantly expand the measurement range of the parameters of the helicopter air velocity vector and obtain information about its spatial position — slip angle β and angle of attack α.

The conversion of primary informative pressure signals p _i into electrical signals convenient for subsequent processing is carried out using pneumoelectric, for example, hot-wire anemometers (VA Ferenets. Semiconductor ink-jet hot-wire anemometers. M.: Energy, 1972, 112 pp.) - [7].

Figure 5 shows a structural diagram of a system of air signals of a helicopter based on a fixed multichannel flow-through aerometric receiver and hot-wire anemometric measuring transducers (channels), made according to the prototype.

The system comprises a fixed multichannel aerometric receiver (AMP) located in the yaw plane, pressure cavities p _i perceived by full pressure tubes, which are connected by pneumatic channels to the input of the averaging chamber and to the input of hot-wire anemometric transducers (TAP). The cavity of the static pressure p _c AMP by a pneumatic channel is connected to the input of the pneumoelectric transducer (sensor) of the static pressure generating an electric signal U _c proportional to the static pressure p _c . At the output of the averaging chamber, a reference pressure p _{0 is formed} , which is supplied via pneumatic channels to other TAP inputs and to the input of the compensation TAP, at the output of the electrical measuring circuit of which a compensation (reference) signal U _{0 is} generated. Electrical measuring circuits TAP form electrical signals U _i proportional to pressures p _i . The outputs of the TAP electrical measurement circuits are connected to the inputs of the analog signal processing circuits, the other inputs of which are connected to the output of the compensation TAP electrical measurement circuit. The compensation signal U _{0 is} used as a reference for the implementation in the electronic unit of the differential method for processing analog signals U _i in the circuits, which allows to reduce the error due to changes in environmental parameters. The outputs of the analog signal processing circuits are connected to a multiplexer connected to an analog-to-digital converter (ADC) connected to a microprocessor.

During the operation of the system, the perceived AMP of the pressure p _i using TAP and electrical measuring circuits is converted into electrical signals U _i proportional to the pressures p _i , which are fed to the microprocessor through the analog signal processing circuits, multiplexer, and ADC. The microprocessor, processing the received signals in accordance with the above algorithms, forms the output

signals in terms of airspeed V _in , angle of attack α and glide angle β. Processing the signal U ₀ from the output of the static pressure sensor, an output signal is generated at the output of the microprocessor according to the barometric altitude H and vertical speed V _y = dH / dt.

The use of a fixed flow-through multi-channel aerometric receiver allows you to expand the measurement range by sliding angle to ± 180 °, to provide noise-resistant measurement of the angle of attack, airspeed, barometric altitude and vertical speed of the helicopter, including at low flight speeds. At the same time, the use of hot-wire anemometric converters of aerometric signals-pressures into an electric signal, due to their high sensitivity in the range of small pressure drops, allows expanding the lower boundary of operating flight speeds to 3 ... 5 km / h - [6].

The disadvantage of the helicopter air signal system is the narrow range of measurement of the angle of attack of the helicopter according to dependence (7), limited to ± 30 ... 40 ° [2]. In addition, at low flight speeds, when the stationary multichannel aerodynamic receiver is in the vortex column alignment and the aerodynamic field near the helicopter is strongly disturbed by the inductive flow of the rotor, the allocation of static pressure p _c becomes impossible, especially when changing the angle of attack of the helicopter in a wide range. The absence of error-correcting information on static pressure leads to significant errors in determining the barometric height H = ƒ (p _c ) and the vertical component of the true airspeed vector V _y = dH / dt.

It should be noted that the instrumental errors of the air signal system, which are caused by the non-identity (scatter) and instability of the characteristics of pneumoelectric, for example, hot-wire anemometric transducers, are easily eliminated when

the implementation of adaptive automatic adjustment of their measuring channels (RF Patent No. 41875 for a utility model. Helicopter air signal system. IPC G 01P 5/00. // Soldatkin V.V., Soldatkin V.M., Porunov A.A. publ. BI No. 31, 2004) - [8].

The technical result to which the claimed invention is directed is to increase the accuracy of measuring the altitude and speed parameters of the helicopter in the low-speed region by obtaining and using additional information about the angular position (bevel angles) of the rotor column of the rotor of the helicopter and by increasing the noise immunity of the perceived static pressure to the pulsations of the velocity vector of the inductive flow of the rotor and to a change in the angle of attack of the helicopter in a wide range.

Using the proposed helicopter airborne signal system can improve flight safety and the effectiveness of solving flight-navigation and combat missions, for example, accuracy of shooting and bombing, due to the high-precision and omnidirectional (when changing the position of the helicopter in three-dimensional space) determination of the altitude and speed parameters of the helicopter in a wide range speeds, including the region of low and near-zero flight speeds.

The technical result is achieved by the fact that in the helicopter air signal system containing a flow multichannel aerometric receiver installed in the yaw plane, the chokes of the throttled static pressure and full pressure tubes of which are connected to pneumatic-electric converters, the outputs of the electrical measuring circuits of which are connected through a multiplexer and an analog-to-digital converter to a microprocessor, the output of which is the output of the system for high-speed parameters of the helicopter, new is the fact that it additionally introduced disposed orthogonally to the first second flow aerometric multichannel receiver cavity

throttled static pressure and full pressure tubes which are connected to additional pneumatic-electric converters, the outputs of the electrical circuits of which are connected through a multiplexer and an analog-to-digital converter to a microprocessor to determine the rotor angles of the rotor column of the helicopter in the region of low flight speeds, and calculate the components of the airspeed vector and determining the altitude and speed parameters of the helicopter, according to the system of equations niy

where V _x , V _y , V _z are the components of the helicopter air velocity vector on the axis of the associated velocity coordinate system; β _VK and α _VK are the bevel angles of the vortex column in the yaw plane and in the plane orthogonal to it; a _β and a _α are the coupling coefficients of the lateral V _z and longitudinal V _x components of the vector helicopter airspeed with bevel angles β _VK and α _{VK of the} vortex column of the helicopter support system in the yaw plane and in the plane orthogonal to it in the region of low flight speeds; and _p is the coupling coefficient of the vertical velocity V _y with the rate of change of the throttled static pressure p _{c t} ; H, V _in , α and β - barometric height, value

(vector module) airspeed of the helicopter, angle of attack and glide angle; R is the gas constant of air; Т = Т ₀ + τН - outdoor temperature; τ is the altitude temperature gradient; p ₀ and T _{0 -} static pressure and temperature at ground level; _r.s.t. - throttled static pressure perceived by orthogonally located flowing multi-channel aerometric sensors. Pneumoelectric converters are made by hot-wire anemometric.

The invention is illustrated in Fig.6 - Fig.7.

Figure 6 presents a General view of the aerometric unit of the helicopter air signal system in the form of two orthogonally located multi-channel aerometric sensors 1, 2, which allows you to measure the angular position (bevel angles) of the airspeed vector helicopter rotor vortex columns in the longitudinal and vertical planes of the associated high-speed coordinate system.

Figure 7 presents the structural and functional diagram of the system of air signals of a helicopter using hot-wire transducers of perceived pressure into electrical signals.

Here 1, 2 are orthogonally located aerometric sensors; 3 - full pressure tubes; 4 - cavity static pressure; 5 - averaging chamber; 6 - hot-wire transducer of static pressure; 7 - hot-wire anemometric pressure transducers perceived by full pressure tubes; 8 - electrical measuring circuits; 9 is a diagram of the processing of analog signals; 10 - multiplexer; 11 - analog-to-digital Converter; 12 - microprocessor.

The system comprises a stationary multichannel aerometric receiver 1 located in the yaw plane and a stationary multichannel aerometric sensor located orthogonal to the receiver 1 in a plane perpendicular to the yaw plane

receiver 2. The pressures p _{i are} received by the tubes of full pressure 3. The cavities of the throttled static pressures p _st , perceived by the ring receivers 4, are connected to the averaging chamber 5 connected to the pneumoelectric (for example, thermoanemometer) transducer 6, at the output of which an electric signal U ₀ proportional to the averaged static pressure p _c . The full pressure tubes 4 are connected to the inputs of the hot-wire transducers 7, the electrical measuring circuits 8 of which form electrical signals U ₁ , U ₂ , ..., U _i proportional to the pressures p _i . The outputs of the electrical measuring circuits 8 are connected to the inputs of the analog signal processing circuits 9, the other inputs of which are connected to the output of the hot-wire transducer 6, which generates an electrical signal U ₀ proportional to the static pressure p _c . The signal uq is used as a reference for the implementation of the differential method of processing analog signals U _i in circuits 9, which reduces the influence of environmental parameters. The outputs of the analog signal processing circuits 9 through a series-connected multiplexer 10 and an analog-to-digital converter 11 are connected to the microprocessor 12 to determine the angles of the rotor column of the rotor of the helicopter, used to calculate the components of the airspeed vector and determine the altitude-speed parameters of the helicopter.

The airborne signal system of the helicopter operates as follows.

The fixed aerometric unit (Fig. 6), consisting of two orthogonally located flow-through multi-channel aerometric sensors 1, 2, is mounted on the fuselage of the helicopter and oriented along the axes of the associated velocity coordinate system.

When the system is running, the flow-through multi-channel aerometric receiver 1 (Fig. 7) in the yaw plane highlights in the oncoming plane

the air stream of the vortex column is a plane-parallel air stream in which it generates pressures proportional to the throttled static pressure p _st and pressure p _i characterizing the bevel angle of a plane-parallel air stream (stream). Using pneumoelectric, for example, hot-wire transducers 6, 7 and circuits 8, 9, the perceived pressures p _c and p _{i are} converted into electrical signals U _i , which are input through a multiplexer 10 and an analog-to-digital converter 11 into a microprocessor 12. Flow multi-channel aerometric receiver 2 selects a plane-parallel air stream in a plane orthogonal to the yaw plane in the incident air flow of the vortex column in the incident air flow, in which pressure signals are generated and converted into electric signals, respectively pressure throttling static pressure p _st and pressure p _i characterizing the bevel angle of an orthogonal plane-parallel air stream, which are introduced through the multiplexer 10 and analog-to-digital converter 11 (Fig. 7) into the microprocessor 12. The microprocessor processes the introduced electrical signals according to the developed algorithms , determines the angles of position (bevel) of the vortex column, which calculates the components of the airspeed vector and determines the altitude and speed parameters of the helicopter.

When installing an aerometric unit made in the form of two orthogonally located flow-through multichannel aerometric sensors, two characteristic regimes of the flow around the incoming air flow take place in the nose of the helicopter fuselage.

At flight speeds of more than 50 ... 70 km / h, when the aerometric unit is located outside the rotor vortex column, the components of the airspeed vector on the axis of the associated velocity coordinate system are determined in accordance with a system of equations of the form

where: β = ψ _β and α = ψ _α are the glide and attack angles of the helicopter equal to the bevel angles of the plane-parallel air stream in the yaw plane ψ _β and the air stream in the plane ψ _α orthogonal to it.

The module (value) of the true airspeed vector determined by the ratio

The barometric height H is determined by the information on the magnitude of the throttled static pressure p _s.t. received from multichannel aerometric sensors, according to the ratio

where: R is the gas constant of air; Т = Т ₀ + τН - outdoor temperature; τ is the altitude temperature gradient; p ₀ and T ₀ - static pressure and temperature at ground level.

In the region of low flight speeds, when the aerometric unit with flow multichannel aerometric sensors is in the alignment of the rotor column of the rotor of the helicopter, the angular position of the rotor column of the rotor of the rotor of the helicopter, determined by the bevel angles β _VK = ψ _β and α _VK = ψ _α which are recorded by orthogonally located flow multichannel receivers and are determined in accordance with equations of the form ( 5).

As studies have shown (Kaletka J. Evaluation of the Helicopter Low Airspeed System Lassie. // Jornal of American Helicopter Society, 1983, No. 4. p. P. 35-43) - [9], the angular position of the helicopter vortex column when flying on

low speeds can be represented as

Where and a _α , a _β are functions and coefficients determined by the results of flight tests of this type of helicopter.

In this case, for each value of α _VK located in the zone of the vortex column, it is possible to determine two values β _VKmax and β _VKmin defining the boundaries of the angular position of the vortex column in the orthogonal plane. Therefore, for the criterion for the location of the aerometric block in the zone of the vortex column, for each α _VC value, the condition

Subject to this condition, i.e. when flying a helicopter at low speeds, the algorithms for determining the altitude and speed parameters of the helicopter have the form

where a _p is the coupling coefficient of the vertical velocity with the rate of change of static pressure.

In case of non-fulfillment of condition (12), the vortex column does not cover the helicopter glider and the flight is carried out in the mode when the aerometric unit with multi-channel aerometric receivers has gone beyond

vortex columns.

It should be noted that in such a system of air signals of a helicopter, the accuracy of perception of static pressure p _{c is} also significantly increased, since the aerometric unit in the form of two orthogonally located flow-through multi-channel aerometric receivers allows:

- to form plane-parallel air jets within the planes of the right and left shielding disks of multichannel aerometric sensors and perform spatial averaging of the static pressure signal by arranging the static pressure receiving holes around the circumference and using the averaging groove;

- reduce the influence of the slip angle β due to the location of the receiving holes of the static pressure on the right and left shielding disks;

- smooth out static pressure pulsations by increasing the number of local static pressures perceived on two orthogonally located multi-channel aerometric receivers.

Thus, the extraction of two plane-parallel air jets in the yaw plane and in the plane orthogonal to it using orthogonally located flow multichannel aerometric receivers, the formation of pressures characterizing the throttled static pressure in the jets and the pressure characterizing their bevel angles, converting the pressure into electrical signals with using pneumoelectric, for example, hot-wire anemometric transducers and sequential determination of the angular position (bevel angles ) the rotor column of the rotor and then the air signals of the helicopter can improve the accuracy of measuring altitude-speed parameters, expand the operating ranges in terms of angle of attack and speed, especially in the region of low and near-zero flight speeds.

The use of an airborne signal system with improved technical characteristics makes it possible to increase the safety of controlling and piloting a helicopter, and to increase the efficiency of performing flight-navigation and special tasks.

Claims (2)

1. The helicopter air signal system comprising a flow multichannel aerometric receiver mounted in the yaw plane, the chokes of the throttled static pressure and full pressure tubes of which are connected to pneumoelectric converters, the outputs of the electrical measuring circuits of which are connected to a microprocessor through a multiplexer and an analog-to-digital converter, the output of which is the output of the system according to the altitude and speed parameters of the helicopter, characterized in that it is additionally introduced a second flow multichannel aerometric receiver located orthogonally to the first, the chokes of the throttled static pressure and full pressure tubes of which are connected to additional pneumatic-electric converters, the outputs of the electrical measuring circuits of which are connected through a multiplexer and an analog-to-digital converter to a microprocessor to determine bevel angles in the region of low flight speeds helicopter rotor vortex column torus airspeed and altitude-determining speed parameters of the helicopter, according to the system of equations

where V _x , V _y , V _z are the components of the helicopter air velocity vector on the axis of the associated velocity coordinate system; β _VK and α _VK are the bevel angles of the vortex column in the yaw plane and in the plane orthogonal to it; and _β and a _α are the coupling coefficients of the lateral V _z and the longitudinal V _x components of the vector

helicopter airspeed with bevel angles β _VK and α _{VK of the} vortex column of the helicopter support system in the yaw plane and in the plane orthogonal to it in the region of low flight speeds; and _p is the coupling coefficient of the vertical velocity V _y with the rate of change of the throttled static pressure p _{c t} ; H, V _in , α and β - barometric altitude, magnitude (vector module) of the airspeed of the helicopter, angle of attack and glide angle; R is the gas constant of air; Т = t ₀ + τН - outdoor temperature; τ is the altitude temperature gradient; p ₀ and T ₀ - static pressure and temperature at ground level; _r.s.t. - throttled static pressure perceived by orthogonally located flowing multi-channel aerometric sensors. 2. The helicopter air signal system according to claim 1, characterized in that the pneumatic converters are thermoanemometric.