RU2737518C1 - Kinematic sensor of aerodynamic angle and true air speed - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: invention can be used for measurement of value (module) and angle of direction (aerodynamic angle) of aircraft true air velocity vector. Essence of the invention consists in that to the inertial sensor of aerodynamic angle and true air speed contains a board with receivers, recording parameters of the incoming air flow, measuring circuit, computing device for processing and generating output signals, wherein receivers are made in form of two superimposed pairs of piezoelectric emitters-receivers of ultrasonic oscillations in direction of incident airflow and against it, installed orthogonal to each other at an angle Θ₀=45° to axis of board, relative to which value of aerodynamic angle is counted, wherein inputs of piezoelectric emitters through elements of measurement circuit—modulators are connected to generator of sinusoidal oscillations of high frequency, and piezoelectric receivers through amplifiers and detectors of measurement circuit are connected to inputs of two frequency subtracting circuits, at the output of which there are formed frequency differences of pairs of receivers receiving ultrasonic oscillations in opposite directions, outputs of frequency subtracting circuits are connected to input of computing device for processing and generation of output signals, made in form of computer, which outputs are digital outputs on aerodynamic angle α and true air speed V_B determined in accordance with predetermined algorithms.

EFFECT: simplification of design, improvement of measurement accuracy, reduction of number of measuring channels and simplification of measuring circuit and device of information processing and generation of output signals.

1 cl, 6 dwg

Description

The invention relates to the field of instrumentation, in particular to devices for measuring the magnitude (module) and the angle of direction of the velocity vector of a moving object relative to the surrounding air and can be used in the sensor of the aerodynamic angle (angle of attack or slip) and the true airspeed of an aircraft, in particular aircraft.

Known devices for measuring the magnitude and angle of the direction of the velocity vector of the gas (air) flow, which implement the aerodynamic method of measurement (Petunin AN Methods and techniques for measuring the parameters of the gas flow. Receivers of pressure and velocity head). M .: Mechanical Engineering, 1972. 332 p.) - [1]; (Gorlin SM, Slezinger II Aeromechanical measurements. Methods and instruments. Moscow: Nauka, 1964. 636 pp.) - [2].

In such devices, a pressure receiver is introduced into the controlled incoming air flow, for example, in the form of a spherical or cylindrical body, which perceives the total and static pressure of the incoming air flow, which determines the magnitude (modulus) of the incoming air flow velocity vector. The same receiver senses pressures that carry information about the angular position of the incoming air flow velocity vector relative to the pressure receiver axis, which are used to determine the direction angle of the incoming air flow velocity vector. The value of the angle of direction of the velocity vector of the incoming air flow uniquely determine the aerodynamic angle and the true airspeed of the aircraft, in particular the aircraft.

The use of such devices for measuring the magnitude (modulus) and aerodynamic angle (angle of attack or slip) of the airspeed vector of an aircraft, in particular an aircraft, is associated with methodological and instrumental errors in the perception, transmission, conversion and processing of amplitude pneumatic informative signals (pressures, pressure drops , temperature) caused by changes in the state of the surrounding air environment (density, atmospheric pressure and temperature, humidity, pollution, etc.), as well as with additive and multiplicative errors in amplitude measurements of the used pressure sensors, pressure drops, temperature associated with zero drift and changing the sensitivity of the primary information sensors. The possibility of clogging, freezing, dust and moisture ingress into the openings of the receivers for sampling static and total pressures and pressures that determine the angle of direction of the incoming air flow, reduce the reliability of the aerometric sensor of the aerodynamic angle and true airspeed.

Known device for measuring the angle of direction and speed of the incoming air flow, built on the basis of the vortex method, which uses the effect of formation and periodic breakdown of vortices behind bluff bodies, such as wedge-shaped (RF patent for invention No. 2506596, IPC G01P 5/00. Publ. 10.02 .2014. Bull. No. 4) - [3].

In such a device designed for simultaneous measurement of the aerodynamic angle and true airspeed, two wedge-shaped bodies are installed in the incoming air flow with their bases opposite to the oncoming air flow. In this case, the bases of the wedge-shaped bodies have the same dimensions and are located orthogonal to each other. On the rear surfaces of the wedge-shaped bodies there are channels for registering the frequencies of vortex formation behind the bodies, including receivers of pressure pulsations on the rear surfaces, connected with frequency registration schemes that measure the frequencies of vortex formation behind the wedge-shaped bodies. Frequency registration circuits are connected to the input of the calculator, at the output of which the values of the aerodynamic angle and true airspeed are formed in accordance with the developed algorithms.

Such a vortex sensor of the aerodynamic angle and true airspeed has one fixed receiver of the incoming air flow information. Vortex frequencies are used as primary informative signals, the extraction, transformation and processing of which is carried out with small errors. However, stable vortex formation behind bodies, including wedge-shaped bodies, occurs in a limited range of oncoming air flow velocities and in a limited range of the flow direction angle, which limits the measurement range of the aerodynamic angle to ± 20 ... 25 °, true air speed in the range from 50 to 600 … 800 km / h.

Known devices for measuring the aerodynamic angle and true airspeed of a moving object, implementing the marking method of measurement, in which a mark is introduced into the incoming air flow and the speed and direction (trajectory) of the mark movement together with the flow are controlled with the help of recorders (US Patent No. 2872609, class 73 -180. 1959) - [4]; (Japanese Application No. 49 - 622, G01C 17/26, 1972) - [5], (USSR Inventor's Certificate No. 735065, G01C 21/12. 1980) - [6].

For the prototype was taken the mark sensor of the aerodynamic angle and airspeed (RF patent for invention No. 2445634, IPC G01P 5/00, G01P 5/18, G01C 21/12. Publ. 03/20/2012. Bul. No. 8) - [7].

Such a prototype device contains a generator of ion marks, a system of receiving electrodes (receivers of parameters of an incoming air flow), a channel for registering ion marks, a measuring circuit, a computing device for processing and generating output signals. The system of receiving electrodes is made in the form of round metal plates, which are located at the same distance around the circumference with the center at the point of generation of the ion label and are installed directly under the hole of the metal plate-mask fixed on the dielectric board. The receiving electrodes are connected to the inputs of the preamplifiers of the ion mark registration channel. The outputs of the preamplifiers are connected via analog switches (switches) and adders to the inputs of the differential amplifiers of the ion mark registration channel.

In the marking sensor of the aerodynamic angle and true airspeed, the measuring circuit is made in the form of a channel for determining the working sector of the measured angle, which is a coarse readout channel, a channel for accurate angle measurement and an airspeed measurement channel connected to the input of a computing device, the outputs of which are digital outputs for the aerodynamic angle and true airspeed.

In the marking sensor of the aerodynamic angle and airspeed, the channel for determining the working sector of the measured angle (coarse readout channel) is made in the form of four identical channels corresponding to one of the four working sectors of the aerodynamic angle measurement range, each of which includes two adders, to the input of the first of of which the outputs of the odd preamplifier modules of this working sector are connected, and the outputs of the even preamplifier modules of this working sector of the measured angle are connected to the input of the second adder, while the outputs of the adders of each of the four identical channels are connected to the outputs of the differential amplifiers, the outputs of which are connected through switches to the input computing device.

In the marking sensor of the aerodynamic angle and airspeed, the channel for accurate measurement of the angle is made in the form of two identical parallel conversion channels, the first of which is connected to the outputs of the even preamplifier modules of this channel, which form an informative signal, the value of which has a sinusoidal dependence on the measured angle, and the second channel conversion is connected to the outputs of the odd preamplifier modules that form an informative signal, the value of which has a cosine dependence on the measured angle, while the conversion channel that forms a sinusoidal dependence on the measured angle includes two adders, the inputs of the first of them are connected to the outputs of the even preamplifier modules that form sinusoidal dependence on the measured angle with a plus sign, and the inputs of the second adder are connected to the outputs of the even preamplifier modules, which form a sinusoidal dependence on the measured angle with a min sign must, and the conversion channel, which forms the cosine dependence on the measured angle, includes two adders, the inputs of the first of them are connected to the outputs of the odd preamplifier modules that form the cosine dependence on the measured angle with a plus sign, and the inputs of the second adder are connected to the outputs of the odd preamplifier modules , forming a cosine dependence on the measured angle with a minus sign, and the outputs of the adders of each of the identical parallel conversion channels are connected to the inputs of differential amplifiers, the outputs of which are connected to the inputs of programmable amplifiers, the control inputs of which are connected to a computing device, and the outputs of the programmable amplifiers through integrators and analog -digital converters are connected to the input of the computing device, which also controls the start of the analog-to-digital converters, and the outputs of the programmable amplifiers are connected to the computing through comparators th device.

In the mark sensor of the aerodynamic angle and airspeed, the signal coming from the computing device to the control input of the programmable amplifiers of the precise angle measurement channel is formed by the computing device according to the signals coming from the outputs of the analog-to-digital converters of two identical parallel conversion channels, in accordance with the algorithm

(Asinα) ² + (Acosα) ² = A ² (sin ² α + cos ² α) = A ² ,

where A is the value (amplitude) of the output signals of the preamplifiers, which form a sinusoidal and cosine dependence on the measured angle α.

In the aerodynamic angle and airspeed marker, the airspeed measurement channel is made in the form of two comparators, the inputs of which are connected to the outputs of the programmable amplifiers of the channel for accurate measurement of the aerodynamic angle, and the outputs, which are the output by the time of flight of the ionic mark, the distance from the point of receiving electrodes are connected to a computing device.

FIG. 1 shows a functional diagram of the aerodynamic angle and airspeed sensor. FIG. 2 shows a structural diagram of the receiving electrode system. FIG. 3 shows the principle of the formation of sinusoidal and cosine informative signals using discrete receiving electrodes. FIG. 4 shows the structural and functional diagram of the channel for determining the working sector of the measured aerodynamic angle (rough reading channel). FIG. 5 shows the structural and functional diagram of the channel for precise measurement of the aerodynamic angle and the airspeed channel.

The functional diagram of the aerodynamic angle and airspeed marker sensor (Fig. 1) contains a board 1 with a system of PE receiving electrodes in the form of round metal plates located at the same distance around a circle of radius R centered at the point 0 of the ion marker generation. The receiving electrodes are connected to the inputs of the PU preamplifiers of the ion mark registration channel located in the BPU preamplifier unit. Receiving electrodes are made in conjunction with preamplifiers in the form of autonomous modules with a shielding housing located in the control room. The outputs of the preamplifier unit are connected to the input of the precise angle measurement channel (the channel of the precise measurement of the aerodynamic angle), to the input of the airspeed measurement channel and to the input for determining the working sector of the measured aerodynamic angle (coarse reading channel). The outputs of all these channels are connected to the input of the computing device VU, the outputs of which are digital codes for the aerodynamic angle N _α and for the air speed N _V.

At the output of the VU computing device, the output signal F _hm is also generated, which is the control input of the GM mark generator and sets the frequency of generation of ion marks and the beginning of the cycle for measuring the aerodynamic angle and air speed.

Structurally, the system of receiving electrodes from the point of view of technological reproducibility is expedient to be made on the basis of a metal mask (Fig. 2). The mask is a thin metal plate on which there are holes located at the same distance l along a circle with a radius R. Under the mask there is a dielectric board with PE receiving electrodes, which are located directly under the holes of the metal mask.

This design of the system of receiving electrodes is simple enough to implement and allows for high accuracy of the formation of sinusoidal and cosine angular characteristics of the informative signals of the receiving electrodes (Fig. 3). The shape of the angular characteristic of the multi-element electrode system is determined by the shape of the characteristic of a separate discrete receiving electrode, the mutual arrangement of the electrodes and the circuit for connecting them to the preamplifiers of the ion label registration channel (Fig. 3).

The task of synthesizing the angular characteristics of the receiving electrodes is to find the design parameters of the mask that ensure the formation of sinusoidal and cosine angular characteristics.

The proposed marking sensor of the aerodynamic angle and airspeed includes two channels for measuring the aerodynamic angle - the channel for determining the number i of the working sector α _{0 of the} measured angle, which is a rough readout channel, and the channel for accurate measurement of the angle α ₀ within the i working sector.

The channel for determining the working sector of the measured angle (coarse readout channel) (Fig. 4) is made in the form of four identical channels corresponding to one of the four working sectors of the range of variation of the measured aerodynamic angle, each i-th identical channel includes two summers SUM, the inputs of which connected to the outputs of the preamplifiers of the PU of their sector (for example, to the outputs of the preamplifiers PU with the numbers No. indicated in Fig. 4), the outputs of the summators SUM are connected to the input of the differential amplifier DU _i , the output of which is connected to the input of the comparator K _i , the output of which is the output of the i-th working sector and indicates the hit (or absence) of the trajectory of the ion tag in the i-th working sector and is connected to the computing device WU.

The channel for accurate measurement of the aerodynamic angle (Fig. 5) is made in the form of two identical parallel conversion channels, the first of which is connected to the outputs of the even PU preamplifier modules (for example, to the outputs of the PU preamplifiers with the numbers indicated in Fig. 5), which form an informative a signal, the value of which has a sinusoidal dependence on the measured angle, and the second parallel conversion channel is connected to the outputs of the odd PU preamplifier modules (for example, to the outputs of the PU preamplifiers with numbers No. indicated in Fig. 5), which form an informative signal, the value of which has cosine dependence on the measured angle.

The conversion channel, which forms a sinusoidal dependence on the measured angle, includes two SUM adders. The inputs of the first of them SUM + sin are connected to the outputs of the even preamplifier modules PU, forming a sinusoidal dependence on the measured angle with a plus sign (+ sin) (for example, to the outputs of the preamplifiers PU with the numbers No. indicated in Fig. 5). The inputs of the second adder SUM -sin are connected to the outputs of the even preamplifier modules PU, forming a sinusoidal dependence on the measured angle with a minus sign (-sin) (for example, to the outputs of the preamplifiers PU with numbers No. shown in Fig. 5).

The second parallel conversion channel, which forms a cosine dependence on the measured angle, includes two SUM adders. The inputs of the first of them SUM + cos are connected to the outputs of the odd preamplifier modules PU, forming a cosine dependence on the measured angle with a plus sign (+ cos) (for example, to the outputs of the preamplifiers PU with the numbers No. shown in Fig. 5). The inputs of the second adder SUM -cos are connected to the outputs of the odd preamplifier modules PU, forming a cosine dependence on the measured angle with a minus sign (-cos) (for example, to the outputs of the preamplifiers PU with numbers No. shown in Fig. 5).

The outputs of the SUM adders of each of the parallel conversion channels are connected to the inputs of the differential amplifiers DU1 and DU2, the outputs of which are connected to the inputs of the programmable amplifiers UP1 and UP2, the control inputs of which are connected to the AGC (automatic gain control) output of the VU computing device. The outputs of the programmable amplifiers through the integrators IHTsin and IHTcos and analog-to-digital converters ADCsin and ADCcos are connected to the input of the computing device VU, which also controls the start of the analog-to-digital converters ADCsin and ADCcos.

The AGC signal (automatic gain control), coming from the computing device VU to the control inputs of the programmable amplifiers UP1 and UP2 of the channel for accurate measurement of the aerodynamic angle, is generated by the computing device VU according to the signals received from the outputs of the analog-to-digital converters ADCsin and ADCcos of identical parallel conversion channels in accordance with with algorithm

(Asinα) ² + (Acosα) ² = A ² (sin ² α + cos ² α) = A ² ,

where A is the value (amplitude) of the output signals of the preamplifiers, which form a sinusoidal and cosine dependence on the measured angle a.

The airspeed measurement channel (Fig. 5) is made in the form of two comparators K1 and K2, the inputs of which are connected to the outputs of the programmable amplifiers UP1 and UP2 of the channel for accurate measurement of the aerodynamic angle, the outputs of the comparators K1 and K2, which are the output in time τx of _the flight with an ionic distance marker R from the point of generation of the ion label to the circle with the receiving electrodes (Fig. 1), are connected to the computing device VU, the output of which N _{V is} proportional to the air speed

The aerodynamic angle and airspeed mark sensor works as follows.

воздушной скорости. Цикл измерения начинается с подачи с выхода вычислительного устройства ВУ сигнала F_гм. В соответствии с сигналом F_гм генератор метки ГМ выдает импульс высоковольтного напряжения на разрядник, установленный в точке 0 генерации ионной метки. За счет искрового разряда разрядника в точке 0 образуется ионизированная область - ионная метка с явно выраженным электростатическим зарядом q_м. Заряженная ионная метка перемещается совместно с набегающим воздушным потоком и приобретает его параметры движения - скорость V и направление α относительно оси симметрии системы приемных электродов ПЭ. При перемещении ионной метки совместно с набегающим воздушным потоком заряженная ионная метка пролетает вблизи приемных электродов и наводит (индуцирует) на них электрические заряды, величина которых зависит от расстояния ионной метки от приемного электрода и углового положения а траектории движения ионной метки.The mark sensor of aerodynamic angles and airspeed is installed on the aircraft in such a way that the board 1 with the system of the receiving electrodes of the PE (Fig. 1) is in the plane of the change in the aerodynamic angle α of the vector

airspeed. The measurement cycle begins with the submission from the output of the computing device WU of the signal F _hm . In accordance with the signal F _gm, the GM tag generator outputs a high-voltage pulse to the spark gap installed at the point 0 of the ion tag generation. Due to the spark discharge of the spark gap at point 0, an ionized region is formed - an ion mark with a pronounced electrostatic charge q _m . The charged ion tag moves together with the incoming air flow and acquires its motion parameters - the speed V and the direction α relative to the symmetry axis of the system of the receiving electrodes of the PE. When the ion tag moves together with the incoming air flow, the charged ion tag flies near the receiving electrodes and induces (induces) electric charges on them, the value of which depends on the distance of the ion tag from the receiving electrode and the angular position on the trajectory of the ion tag.

By choosing the design parameters of the system of receiving electrodes (Fig. 2) with the help of even receiving electrodes, for example Nos. 4, 8, 12, 16, positive half-waves (+ sinα) of sinusoidal angular characteristics of informative signals U (α) are formed (Fig. 3 ) at the output of even preamplifiers, for example, PU # 4, 8, 12, 16 (Fig. 5). With the help of even receiving electrodes, for example, No. 2, 6, 10, 14, negative half-waves (-sinα) of sinusoidal angular characteristics of informative signals U (α) (Fig. 3) are formed at the output of even preamplifiers, for example, PU No. 2, 6, 10, 14 (Fig. 5).

With the help of odd receiving electrodes, for example, No. 1, 5, 9, 13, positive half-waves (+ cosα) of the cosine angular characteristics of informative signals U (α) are formed at the output of odd preamplifiers, for example, PU No. 1, 5, 9 , 13 (Fig. 5). With the help of odd receiving electrodes, for example, No. 3, 7, 11, 15, negative half-waves (-cosα) of the cosine angular characteristics of informative signals U (α) are formed at the output of odd preamplifiers, for example, PU No. 3, 7, 11 , 15 (Fig. 5).

The output signals of the preamplifiers PU of the preamplifier unit BPU (Fig. 1) are fed to the inputs of the channel for determining the working sector (coarse counting channel) of the measured aerodynamic angle, the channel for accurate measurement of the aerodynamic angle and the channel for measuring the airspeed. The output signals of these channels are fed to the inputs of the computing device VU, which, based on the results of processing the input information, issues digital codes N _α , N _V according to the measured aerodynamic angle α and air speed V _B.

During operation of the channel for determining the working sector of the measured aerodynamic angle (Fig. 5), the output signals of the PU preamplifiers are fed to four identical channels corresponding to one of the four working sectors of the range of variation of the measured aerodynamic angle. Each i-th of four identical channels includes summers SUM, differential amplifiers DU and comparators K. To the inputs of adders connected to the non-inverting (positive) input of each i-th differential amplifier DU _i signals are fed from the preamplifiers PU connected to the receiving electrodes located within the i-th working sector of the aerodynamic angle measurement range. The rest of the receiving electrodes are connected to preamplifiers, the outputs of which are fed to the input of the adder, the output signals of which are connected to the inventory (negative) input of the differential amplifier DU _i .

When the ion tag moves within the i-th working sector, the output signal of the i-th differential amplifier DU _i will be positive within the entire working sector. When the trajectory of movement of the ion tag goes beyond the i-th working sector, the output signal of the i-th differential amplifier DU _i changes sign to the opposite. Consequently, the positive sign at the output of the differential amplifier DU _i indicates that the trajectory of the ion tag has entered the i-th working sector.

When the positive sign of the output of the differential amplifier _i control signal is triggered comparator K _i, whose output signal is generated (character) hit the ion trajectory labels in sector i, which is input to and fixed computing device.

When the trajectory of movement of the ion tag leaves the i-th working sector, it enters another, for example, (i + 1) sector, which will lead to the disappearance of the signal (feature) of the i-th working sector and the appearance of the signal (feature) (i + 1) th working sector.

When the precise channel for measuring the aerodynamic angle is operating, an interpolation method for converting and processing informative signals U (α) generated at the output of the pre-amplifiers of the block of pre-amplifiers BPU is implemented (Fig. 1).

The output signals of the even preamplifiers PU No. 4, 8, 12, 16 (Fig. 5), forming a positive half-wave (+ sinα) of the informative signal U (α), and the output signals of the even preamplifiers PU No. 2, 6, 10, 14, forming a negative half-wave (-sinα) of the informative signal U (α), are fed to the inputs of the SUM + sin and SUM-sin adders, the outputs of which are fed to the input of the differential amplifier DU1, at the output of which both half-waves of the sinusoidal dependence of the angular characteristic of the i-th the working sector of the measuring range of the measured aerodynamic angle, which is fed to the input of the programmable amplifier UP1, in which it is normalized in amplitude using the AGC control signal coming from the computing device. The amplitude-normalized signal Asinα through the integrator IHTsin, which performs the functions of a low-pass filter, is cleared of ripple noise and fed to the input of the analog-to-digital converter ADCsin, the output signal in the form of a digital code N _sinα proportional to Asinα is fed to the computing device VU.

On another identical parallel conversion channel (Fig. 5) using the summators SUM + cos and SUM-cos connected to the outputs of the odd preamplifiers PU # 1, 5, 9, 13 and PU # 3.7, 11, 15 and differential amplifier DU2, programmable amplifier UP2, integrator IHTcos and analog-to-digital converter ADCcos, a digital code N _cosα proportional to Acosα is formed, which is fed to the computing device.

Digital signals proportional to Asinα and Acosα are processed in a computing device, at the output of which a digital code N _{αt is issued} , associated with the value of α _{p of the} measured aerodynamic angle of the exact channel by the ratio

Taking into account the hit of the trajectory of the ion mark in the i-th coarse channel, the current value of the measured aerodynamic angle is determined as

α = iα _o + α _р ,

where α _o - the angle covering the working sector of the coarse reference channel (at i = 4, α _o = 90 °); i is the number of the working sector (i = 1.4).

During the operation of the airspeed measurement channel (Fig. 5), the output signals of the programmable amplifiers UP1 and UP2 of the channel for accurate measurement of the aerodynamic angle are used, which are fed to the inputs of the comparators K1 and K2, the threshold of which is set to the value of the normalized amplitude A of sinusoidal and cosine angular characteristics Asinα and Acosα. When the level A of the output signals of the programmable amplifiers UP1 and UP2 is reached, which corresponds to the time moment τ _{x of} the ion mark _'s passage of the distance R from the point of generation of the ion mark to the circle with the receiving electrodes, the comparators K1 and K2 are triggered and the time interval τ _{V is formed by the} computing device VU. In accordance with the time interval τ _V in the computing device, a digital code N _{V is} generated, proportional to the value of the air speed

Digital codes N _α and N _V are supplied to the means of displaying information to other consumers.

However, the prototype device, an aerodynamic angle and airspeed marker sensor, has a number of disadvantages associated with a large number of receiving electrodes and the complexity of the measuring circuit that records the trajectory and speed of movement of the ion marker formed by the generator and spark gap, separates and converts electric charges induced an ion mark on the recording electrodes, as well as with complex algorithms and software of a computing device that processes information and generates output digital signals for the aerodynamic angle and true airspeed. In addition, the multichannel measuring circuit performing registration, conversion and preprocessing of amplitude measuring signals imposes stringent requirements on the identity and stability of measuring channels, and is the cause of additive and multiplicative measurement errors. Their reduction leads to the need for a careful selection of the elements of the measuring channels, the introduction of correcting links, which complicates the production and increases the cost of the sensor. All this hinders the widespread use of the aerodynamic angle and true airspeed sensor on airplanes and other aircraft.

The technical result to be achieved by the claimed invention is to simplify the design, reduce the cost and increase the measurement accuracy by significantly reducing the number of receivers for recording the parameters of the incoming air flow, reducing the number of measuring channels and simplifying the measuring circuit and computing device for processing information and generating output signals and, as a consequence, ensuring the competitiveness of the application on aircraft, including aircraft of various classes and the purpose of the kinematic sensor of the aerodynamic angle and true airspeed, which implements the kinematic measurement method, in which to measure the kinematic parameters of the aircraft movement (aerodynamic angle and true airspeed), the kinematic parameters of the incoming air flow are controlled and determined directly.

The technical result is achieved as follows.

In the kinematic sensor of the aerodynamic angle and true airspeed, which contains a board with receivers that register the parameters of the incoming air flow, a measuring circuit, a device for processing and generating output signals, the new thing is that the receivers are made in the form of two combined pairs of piezoelectric emitters-receivers of ultrasonic vibrations according to the direction of the oncoming air flow and against it, mounted orthogonally to each other at an angle Θ ₀ = 45 ° to the board axis, relative to which the measured aerodynamic angle is measured, while the outputs of the piezoelectric emitters through the elements of the measuring circuit - modulators are connected to a high frequency sinusoidal oscillator , and piezoelectric receivers are connected through amplifiers and detectors of the measuring circuit to the inputs of two frequency subtraction circuits, at the output of which the frequency differences of pairs of receivers are formed, which perceive ultrasonic vibrations in the opposite direction. in the right directions, the outputs of the subtraction circuits are connected to the input of the device for processing and generating output signals, made in the form of a calculator, the outputs of which are digital outputs for the aerodynamic angle α and true airspeed V _B , determined in accordance with the algorithms

и

- частоты ультразвуковых колебаний, воспринимаемые парами приемников в противоположных направлениях.where L is the distance between piezoelectric emitters and receivers of ultrasonic vibrations;

and

- the frequencies of ultrasonic vibrations perceived by pairs of receivers in opposite directions.

The essence of the invention is illustrated in FIG. 6.

FIG. 6 shows a functional diagram of the kinematic sensor of the aerodynamic angle and true airspeed.

Here 1 is a board with receivers registering the parameters of the incoming air flow; 2 - high frequency sinusoidal oscillator; 3 and 4 - two pairs of combined piezoelectric emitters-receivers of ultrasonic vibrations I1-P1, I1'-P1 'and I2-P2, I2'-P2'; 5 - modulators; 6 - amplifiers; 7 - detectors; 8 - frequency subtraction circuits; 9 - calculator.

The functional diagram of the kinematic sensor of the aerodynamic angle and true airspeed (Fig. 6) contains a board with elements for recording the parameters of the incoming air flow 1. On the outer surface of the board, streamlined by the incoming air flow, two combined pairs of piezoelectric emitters-receivers 3 and 4 of ultrasonic vibrations are installed. orthogonal to each other at an angle Θ ₀ = 45 ° to the axis of the board 1, relative to which the value of the aerodynamic angle is measured. Emitters I1 and I2 provide radiation of ultrasonic vibrations in the direction of the incoming air flow, and emitters I1 'and I2' - against the direction of the flow. Receivers P1 and P2 perceive ultrasonic vibrations propagating in the direction of the incoming air flow, and receivers P1 'and P2' - against the direction of the flow.

частот ƒ₁ и

ультразвуковых колебаний, воспринимаемые приемниками П1 и П1' по направлению набегающего воздушного потока. Аналогично пьезоэлектрические приемники П2 и П2' через усилители У2 и У2', детекторы Д2 и Д2' подключены к схеме вычитания частот СВ2, на выходе которой формируется разность

частот ƒ₂ и

ультразвуковых колебаний, воспринимаемые приемниками П2 и П2' против направления набегающего воздушного потока.The outputs of piezoelectric emitters I1, I2 and I1 'and I2', through the elements of the measuring circuit - modulators M1, M2 and M1 'and M2', installed on the racks on the inner side of the board 1, are connected to the generator 2 (G) of sinusoidal high-frequency oscillations outputs of detectors D1, D2 and D1 'and D2'. Piezoelectric receivers P1 and P1 'through amplifiers U1 and U1', detectors D1 and D1 'are connected to the frequency subtraction circuit CB1, at the output of which a difference is formed

frequencies ƒ ₁ and

ultrasonic vibrations perceived by receivers P1 and P1 'in the direction of the incoming air flow. Similarly, piezoelectric receivers P2 and P2 'through amplifiers U2 and U2', detectors D2 and D2 'are connected to the frequency subtraction circuit CB2, at the output of which a difference is formed

frequencies ƒ ₂ and

ultrasonic vibrations perceived by receivers P2 and P2 'against the direction of the incoming air flow.

The outputs of the frequency subtraction circuits CB1 and CB2 are connected to the input of the calculator, which processes the signals Δƒ ₁ and Δƒ _{2 to} determine the aerodynamic angle α and the true airspeed V _B , in accordance with the algorithms

кинематического датчика аэродинамического угла и истинной воздушной скорости.where L is the distance between the piezoelectric emitters and receivers of ultrasonic vibrations. At the output of the calculator 9, digital (code) output signals N _α and

kinematic sensor of aerodynamic angle and true airspeed.

The kinematic sensor of the aerodynamic angle and true airspeed is installed on an aircraft, in particular on an aircraft, so that the axis of the board 1 with receivers recording the velocity vector V of the incoming air flow is parallel to the longitudinal axis of the aircraft (aircraft), and the streamlined surface of the board was in the plane of change of the measured aerodynamic angle α. If necessary, due to the setting angle, which changes the position of the axis of the board 1 relative to the longitudinal axis of the aircraft, it is possible to change the upper and lower limits of the measurement range of the aerodynamic angle.

When the kinematic sensor of the aerodynamic angle and true airspeed is operating, the generator 2 creates sinusoidal high-frequency oscillations, which are fed through the modulators 5 to the piezoelements of the emitters 3. Emitters 3 send ultrasonic vibrations to the piezoelectric receivers 4 at an angle Θ ₀ to the direction of the velocity vector V of the incoming air flow, and emitters I1 'and I2' - against the direction of the incoming air flow.

The operation of the measuring channels of the kinematic sensor of the aerodynamic angle and true airspeed is based on the difference in the transit time of ultrasonic vibrations from emitters to receivers in the direction of the incoming air flow and against the direction of the flow.

и t₂,

прохождения ультразвуковых колебаний от излучателей до приемников будут определяться соотношениямиWith regard to the combined pairs of emitters-receivers I1-P1, I1'-P1 'and I2-P2, I2'-P2' time intervals t ₁ ,

and t ₂ ,

the passage of ultrasonic vibrations from emitters to receivers will be determined by the ratios

where L is the distance between the emitters I1, I1 'and the receivers P1, P1' of ultrasonic vibrations; a is the speed of sound propagation in air.

As soon as the first electrical oscillations created at the outputs of piezoelectric receivers P1, P1 'and P2, P2', having passed through amplifiers U1, U1 'and U2, U2' and detectors D1, D1 'and D2, D2' enter the modulators M1, M1 'and M2, M2', operating in the trigger mode, modulators 5 close the passage of oscillations from the generator 2 to the piezoelectric elements of the emitters I1, I1 'and I2, I2' and the sending of ultrasonic vibrations from the emitters 3 will stop. Modulators M1, M1 'and M2, M2' reopen after the last ultrasonic vibrations of the first packets reach the piezoelectric receivers P1, P1 'and P2, P2'.

и 2Т₂,

. На входы схемы вычитания СВ1 и схемы вычитания СВ2 будут поступать процессы с частотами ƒ₁,

и ƒ₂,

, определяемых соотношениямиAs a result, packets of ultrasonic vibrations with repetition periods 2T ₁ will pass between the piezoelements of the pair I1-P1 and I1'-P1 'and the pair I2-P2 and I2'-P2',

and 2T ₂ ,

... The inputs of the subtraction circuit CB1 and the subtraction circuit CB2 will receive processes with frequencies ƒ ₁ ,

and ƒ ₂ ,

defined by the relations

и

определяемые соотношениями видаAt the outputs of the subtraction circuits CB1 and CB2, informative signals of the measuring channels are formed in the form of a difference

and

defined by relations of the form

Representing the cosines of the sum and the difference in the form

cos (Θ ₀ + α) = cosΘ ₀ cosα + sinΘ ₀ sinα;

cos (Θ ₀ -α) = cosΘ ₀ cosα-sinΘ ₀ sinα,

, получимand taking Θ ₀ = 45 °, cos45 ° = sin45 ° =

, we get

The sum (Δƒ ₁ + Δƒ ₂ ) and the difference (Δƒ ₁ -Δƒ ₂ ) will be determined as

Then the analytical expression for determining the aerodynamic angle α in the measuring channels of the kinematic sensor of the aerodynamic angle and true airspeed will have the form

The sum of squares Δƒ ₁ ² + Δƒ ₂ ² will be determined by the ratio

Then the analytical expression for determining the value of the true airspeed V _B = V in the measuring channels of the kinematic sensor of the aerodynamic angle and true airspeed will have the form

и N_α кинематического датчика аэродинамического угла и истинной воздушной скорости, которые подаются на средства отображения информации в систему автоматического управления и другим потребителям.The obtained relations (5) and (6) determine the algorithms for processing informative signals Δƒ ₁ and Δƒ ₂ , which are fed from the outputs of the subtraction circuits CB1 and CB2 to the input of the calculator 9. At the output of the calculator 9, output digital (code) output signals are generated

and N _{α of the} kinematic sensor of the aerodynamic angle and true airspeed, which are fed to the means of displaying information in the automatic control system and to other consumers.

Thus, the kinematic sensor of the aerodynamic angle and true airspeed for recording the parameters of the oncoming air flow uses only two receivers, made in the form of combined piezoelectric emitters-receivers of ultrasonic vibrations. The measuring circuit of the kinematic sensor includes only two measuring channels with frequency informative signals, the extraction, transformation and processing of which is provided with less errors than analog signals, which greatly simplifies its implementation. Quite simple algorithms for determining the measured aerodynamic angle and true airspeed simplify the implementation of a calculator that generates digital (code) output signals of the kinematic sensor for the aerodynamic angle and true airspeed. All this simplifies the design, reduces the cost, improves the measurement accuracy and ensures the competitiveness of the use of the kinematic sensor of the aerodynamic angle and true airspeed on aircraft, including aircraft of various classes and purposes.

The use of a kinematic sensor of the aerodynamic angle and true airspeed on aircraft, including airplanes, will improve the accuracy of measuring the aerodynamic angle and true airspeed, which will increase the level of flight safety, especially at extreme modes, improve the quality of piloting and ensure the effectiveness of the tactical and technical solution. flight tasks.

Claims (3)

A kinematic sensor of the aerodynamic angle and true airspeed, containing a board with receivers that register the parameters of the incoming air flow, a measuring circuit, a computing device for processing and generating output signals, characterized in that the receivers are made in the form of two combined pairs of piezoelectric emitters-receivers of ultrasonic vibrations in the direction oncoming air flow and against it, installed orthogonally to each other at an angle Θ ₀ = 45 ° to the axis of the board, relative to which the value of the aerodynamic angle is measured, while the inputs of piezoelectric emitters through the elements of the measuring circuit - modulators are connected to a generator of sinusoidal high frequency oscillations, and piezoelectric receivers, through amplifiers and detectors of the measuring circuit are connected to the inputs of two frequency subtraction circuits, at the output of which the frequency differences of pairs of receivers are formed, which perceive ultrasonic vibrations in opposite directions, the outputs of the frequency subtraction circuits are connected to the input of a computing device for processing and generating output signals, made in the form of a calculator, the outputs of which are digital outputs for the aerodynamic angle α and true airspeed V _B , determined in accordance with the algorithms

where L is the distance between piezoelectric emitters and receivers of ultrasonic vibrations; Δƒ ₁ = ƒ ₁ -ƒ ₁ ^' and Δƒ ₂ = ƒ ₂ -ƒ ₂ ^' , ƒ ₁ , ƒ ₁ ^' and ƒ ₂ , ƒ ₂ ^' are the frequencies of ultrasonic vibrations perceived by pairs of receivers in opposite directions.

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