RU135149U1 - ULTRASONIC FLOW SPEED METER - Google Patents

Abstract

Usage: in instrumentation, namely, in the technique of measuring wind parameters, in particular for measuring horizontal speeds and wind directions, for the vertical component of wind speed and also at airports to ensure flight safety of aircraft. Objective: improving reliability and expanding the temperature range of operation. SUBSTANCE: ultrasonic flow velocity meter, comprising three measuring bases, including two reversible electroacoustic transducers located at an angle of 120 ° relative to each other and at an angle (30-60 °) in a vertical plane, as well as a switch to which a transmitter and receiver are connected pulse signals, three comparators, four triggers, a third-period sine wave selection node, matching device, counter, key device, and a time-to-digital converter in series, bl division, subtraction unit and computing device, as well as a synchronization device, logical adder and six keys, two in each measuring base, while the output of the matching device is connected to the input of the third comparator, the output of which is connected to the first input of the counter, the output of the counter simultaneously connected to the second input of the key device and to the first input of the fourth trigger, the output of which is connected to the second input of the counter, the inputs of the first and second comparators are connected to the switch, the output of the first computer the radiator is connected to the first input of the first trigger, the output of the second comparator is connected to the first input of the selection node of the third sine wave, the output of the first trigger is connected to the second input of the selection node of the third sine wave, the first input of the third trigger is connected to the switch, the output of the third trigger is connected to the first input of the key a device whose output is connected to the first input of the second trigger, and the output of the second trigger is connected to a time-to-digital converter and to a synchronization device, this first the input input of each key is connected to the output of the corresponding electro-acoustic transducer of its measuring base, the outputs of the keys, the inputs of which are connected to the first electro-acoustic transducers of each measuring base, are simultaneously connected to one input of the switch, the outputs of the keys, the inputs of which are connected to the second electro-acoustic transducers of each measuring base, are connected to another switch input, the second key inputs of the first measuring base are connected to the first output of the device synchronously nation, the second key inputs of the second measuring base are connected to the second output of the synchronization device, the second key inputs of the third measuring base are connected to the third output of the synchronization device, the first, second and third inputs of the logical adder are connected to the corresponding outputs of the synchronization device, and its output is simultaneously connected to the switch and a computing device, supplemented by six heaters, two in each measuring base, having direct thermal contact with their electro-acoustic transducer and connected through a second switch to a power source and a temperature controller, also three OR devices, a control device and a second counter, the output of which is connected to the first input of the control device, to the second input of which the output of the temperature controller is connected, and its first output is connected to the control input of the second switch, while the second output is simultaneously connected to the installation (additional) inputs of the synchronization device and computing device VA and the first inputs of the three OR devices, the second inputs of the first and third OR devices connected to the output of the selection node of the third sine wave, the output of the first OR device is simultaneously connected to the second inputs of the first, third and fourth triggers, the output of the third OR device is connected to the second input of the second trigger, the second input of the second device OR is connected to the output of the first trigger, and its output is to the second input of the second counter, the first input of which is connected to the output of the third comparator. 1 n.p. f-ly; 3 ill.

Description

The proposed utility model relates to instrumentation, namely, to a technique for measuring wind parameters, in particular for measuring horizontal wind speeds and directions, as well as the vertical component of wind speed and can be used at airports to ensure aircraft flight safety.

Currently, in the practice of meteorological support for aviation flights, wind parameters sensors, both rotorcraft and acoustic anemometers, are widely used.

Rotorcraft sensors are widely used in domestic and foreign practice, in which wind sensors are used that determine the wind speed by the angular speed of rotation, and the direction - by the location of the turntables along the wind direction due to the presence of weathercocks [1, 2, 3].

At present, they began to use acoustic anemometers for measuring wind speed and its directions [4], which have an advantage, since do not contain mechanically rotating elements (turntables and weathercocks), the presence of which greatly reduces the reliability of wind speed meters and its directions.

The disadvantages of the known technical solutions include the impossibility of measuring the vertical component of the wind speed, which can lead to more complicated landing conditions for aircraft.

Known ultrasonic meter of pulsating flow rates [5], containing two reversible electro-acoustic transducers connected through a switch to a transmitter and a receiver of pulse signals, a time-to-digital converter, the output of which through a division block is connected to the first subtraction unit, a synchronizer and a recorder.

The disadvantages of the known meter include its limited capabilities, because it is intended only for measuring wind speed, and parameters such as wind direction and the vertical component of the wind cannot be measured.

Known ultrasonic flow velocity meter [6], which contains three channels for measuring wind speed I, II and III.

Each of the channels for measuring wind speed includes two reversible electro-acoustic transducers connected through a switch to a transmitter and a receiver of pulse signals, a time-to-digital converter, the output of which through a division block is connected to a subtraction block.

The outputs of the subtraction block of each measurement channel are connected to a computing device.

The electro-acoustic transducers of each channel for measuring wind speed form three measuring bases located at the same distance L at an angle of 120 ° relative to each other and at an angle of (30-60) ° in the vertical plane.

The disadvantages of the known flow velocity meter include the low accuracy of measuring the horizontal and vertical components of wind speeds and wind direction.

Known ultrasonic flow velocity meter [7], containing three channels for measuring wind speed, each of which includes two reversible electro-acoustic transducers connected through a switch to a transmitter and a receiver of pulse signals, a time-to-digital converter, the output of which through a division block is connected to a subtraction unit while the outputs of the subtraction blocks of all three channels for measuring wind speed are connected with a computing device, and the electro-acoustic transducers of each channel are measured Grains of wind speed form three measuring bases located at an angle of 120 ° relative to each other and at an angle of (30-60) ° in the vertical plane.

Each of the three channels for measuring wind speed is supplemented by two comparators, three triggers and a selection unit for the third sinusoid period, while the inputs of the comparators are connected to the switch, the output of the first comparator is connected to the first input of the first trigger, the output of the second comparator is connected to the selection unit of the third period of the sine wave, output the first trigger is connected to the second input of the selection node of the third period of the sine wave, the output of which is connected to the second input of the second trigger, to the second input of the first trigger and to the second the input of the third trigger, in addition, the first input of the third trigger is connected to the switch, and the output of the third trigger is connected to the first input of the second trigger, and the output of the second trigger is connected to the time-to-digital converter.

The disadvantages of the known ultrasonic flow velocity meter include a significant dependence of the accuracy of the measurements on the technological variation of the parameters of electro-acoustic transducers.

Known ultrasonic flow velocity meter [8], containing three channels for measuring wind speed, each of which includes two reversible electro-acoustic transducers connected through a switch to a transmitter and receiver of pulsed signals, two comparators, the inputs of which are connected to the switch, three triggers and a selection unit of the third sine wave period, while the output of the first comparator is connected to the first input of the first trigger, the output of the second comparator is connected to the first input of the selection node of the third period with nusoid, the output of the first trigger is connected to the second input of the selection node of the third period of the sine wave, the output of which is connected to the second input of the second trigger and to the second input of the third trigger, the first input of the third trigger is connected to the switch, the output of the second trigger is connected to the time-to-digital converter, output which through the division block is connected to the subtraction block, the outputs of the subtraction blocks of all three channels for measuring wind speed are connected to a computing device, and the electroacoustic transducers Each channel for measuring wind speed is formed by three measuring bases located at an angle of 120 ° relative to each other and at an angle of (30-60) ° in a vertical plane, while each of the three channels for measuring wind speed is supplemented by a sequentially connected matching device, a third comparator and a counter , the fourth trigger and the key device, while the output of the counter is simultaneously connected to the second input of the key device and the first input of the fourth trigger, the output of which is connected to the second input of the counter, and Ora input connected to the output node of the third selection period sinusoids first input key device connected to the output of the third comparator, and its output - to the first input of the second flip-flop, the input of the matching device is connected to a first input of the third comparator.

The disadvantages of the known ultrasonic flow velocity meter include insufficient reliability, manufacturability and increased material consumption and power consumption, due to the significant number of active devices in each measurement channel. This circumstance leads to manufacturing complexity, increased mass-dimensional indicators, which increases the cost of an ultrasonic flow velocity meter.

The increased mass-overall dimensions and energy consumption limit the possibility of using such devices in portable and automatic weather-powered stations.

The closest technical solution to the proposed utility model is an ultrasonic flow velocity meter [9], containing three measuring bases, including two reversible electro-acoustic transducers located at an angle of 120 ° relative to each other and at an angle (30-60 °) in the vertical plane, as well as a switch to which a pulse signal transmitter and receiver are connected, three comparators, four triggers, a third-period sine wave allocation unit, a matching device, a counter, a key device, and therefore, the connected time-to-digit converter, a division unit, a subtraction unit and a computing device, as well as a synchronization device, a logical adder and six keys, two in each measuring base, while the output of the matching device is connected to the input of the third comparator, the output of which is connected to the first input of the counter, the output of the counter is simultaneously connected to the second input of the key device and to the first input of the fourth trigger, the output of which is connected to the second input of the counter, the inputs of the of the second and second comparators are connected to the switch, the output of the first comparator is connected to the first input of the first trigger, the output of the second comparator is connected to the first input of the allocation node of the third sine wave, the output of the first trigger is connected to the second input of the allocation node of the third sine wave, the output of which is connected to the second inputs the first, second, third and fourth triggers, and the first input of the third trigger is connected to the switch, the output of the third trigger is connected to the first input of the key device, the output is It is connected to the first input of the second trigger, and the output of the second trigger is connected to a time-to-digital converter and to a synchronization device, the first input of each key is connected to the output of the corresponding acoustic transducer of its measuring base, the outputs of the keys, the inputs of which are connected to the first electro-acoustic transducers of each measuring bases simultaneously connected to one input of the switch, key outputs, the inputs of which are connected to the second electro-acoustic transducers of each measuring base, connected to another input of the switch, the second key inputs of the first measuring base are connected to the first output of the synchronization device, the second key inputs of the second measuring base are connected to the second output of the synchronization device, the second key inputs of the third measuring base are connected to the third output of the synchronization device, the first, the second and third inputs of the logical adder are connected to the corresponding outputs of the synchronization device, and its output is simultaneously connected to the switch and calculates Extension Units.

The disadvantages of the known device include low reliability and a limited temperature range of operation.

This is due to the fact that the parameters of electro-acoustic transducers, having a significant technological spread, significantly depend on external factors, especially on the ambient temperature. In addition, the spread in the values of these parameters is enhanced after sealing the ultrasonic transducers and their mechanical fastening in the device design.

It should be noted that the mechanical properties of sealants under the influence of ambient temperature change, leading to additional changes in the parameters of electro-acoustic transducers. Moreover, the accuracy of setting the lengths of the measuring bases in the device is ensured by more rigid mechanical fixation of the electro-acoustic transducers, which leads to an increase in the level of vibrational interference and, therefore, to the need to increase the threshold of operation of the first comparator of the known device by 1.5-2 times.

Thus, the levels of the forward and reverse signals during reception and radiation in each measuring base, significantly differing from each other already in the manufacturing process of the device, during operation as a result of external adverse factors may be lower than the threshold of the first comparator of the known device, which will lead to measurement failures and the appearance of false information.

Moreover, it is known that all electro-acoustic transducers, even Murata firms, have a lower operating temperature threshold of -30 ° C to -40 ° C, which does not meet the operational requirements of meteorological instruments for which the established lower operating temperature threshold is -55 ° C, and is a serious drawback of the device.

In addition, there were cases of icing (ice formation) on the structural elements of the measuring base of the known device when exposed to rain or wet snow at ambient temperatures in the range from 0 ° C to -2 ° C or contamination of the working surfaces of electro-acoustic transducers, which led to a complete loss the health of the known device and the issuance of false information for a long time, because Instruments are installed at considerable distances from control centers for collecting meteorological information.

The main task, which the proposed utility model is aimed at, is to increase reliability and expand the temperature range of operation.

The problem is solved using the proposed ultrasonic flow velocity meter, which, like the prototype, contains three measuring bases, including two reversible electro-acoustic transducers located at an angle of 120 ° relative to each other and at an angle (30-60 °) in the vertical plane, as well as a switch to which a pulse signal transmitter and receiver are connected, three comparators, four triggers, a third-period sine wave extraction unit, a matching device, a counter, a key device, and the last The time-to-digit converter, the division unit, the subtraction unit, and the computing device, as well as the synchronization device, the logical adder, and six keys, two in each measuring base, two in each measuring base, the output of the matching device connected to the input of the third comparator, the output of which is connected to the first input of the counter, the output of the counter is simultaneously connected to the second input of the key device and to the first input of the fourth trigger, the output of which is connected to the second input of the counter, the inputs of the first and the second comparator is connected to the switch, the output of the first comparator is connected to the first input of the first trigger, the output of the second comparator is connected to the first input of the allocation node of the third sine wave, the output of the first trigger is connected to the second input of the allocation node of the third period of the sine wave, the output of which is connected to the second input of the trigger, and the first input of the third trigger is connected to the switch, the output of the third trigger is connected to the first input of the key device, the output of which is connected to the first input of the second trigger era, and the output of the second trigger is connected to a time-to-digit converter and a synchronization device, the first input of each key is connected to the output of the corresponding electro-acoustic transducer of its measuring base, the outputs of the keys whose inputs are connected to the first electro-acoustic transducers of each measuring base are simultaneously connected to one input switch, key outputs, the inputs of which are connected to the second electro-acoustic transducers of each measuring base, are connected to another at the switch input, the second key inputs of the first measuring base are connected to the first output of the synchronization device, the second key inputs of the second measuring base are connected to the second output of the synchronization device, the second key inputs of the third measuring base are connected to the third output of the synchronization device, the first, second and third inputs of the logical the adder is connected to the corresponding outputs of the synchronization device, and its output is simultaneously connected to the switch and the computing device.

Unlike the prototype, the proposed ultrasonic flow rate meter is supplemented by six heaters, two in each measuring base, having direct thermal contact with their electro-acoustic transducer and connected through a second switch to a power source and temperature controller, three OR devices, a control device and a second counter the output of which is connected to the first input of the control device, to the second input of which the output of the temperature controller is connected, e the first output is connected to the control input of the second switch, the second output is simultaneously connected to the installation (additional) inputs of the synchronization device and the computing device and the first inputs of three (all) OR devices, and the second inputs of the first and third OR devices are connected to the output of the third period selection node sine waves, the output of the first OR device is simultaneously connected to the second inputs of the first, third and fourth triggers, the output of the third OR device is connected to the second input of the second trigger a second OR input of the second device is connected to the output of the first flip-flop and its output - to the second input of the second counter having a first input connected to the output of the third comparator.

The essence of the proposed utility model is that, thanks to the introduction of six heaters, two in each measuring base with direct thermal contact with its electro-acoustic transducer, a second switch, three OR devices, a temperature controller, a control device, a second counter and a heating power source and their interaction with other elements of the ultrasonic flow velocity meter, the expansion of the temperature range of functioning and shenie reliability and efficiency of operation in adverse weather conditions.

The proposed utility model is illustrated in the drawing, where

figure 1 - shows a functional diagram of an ultrasonic flow velocity meter;

figure 2 - timing diagrams of the interaction of nodes stabilizing the temperature regime;

figure 3 - timing diagrams of the interaction of nodes in the case of icing (pollution).

The ultrasonic flow velocity meter contains three measuring bases I, II and III, each of which includes two reversible electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _III , connected via keys 3 _I and 4 _I , 3 _II and 4 _II , 3 _III and 4 _III and through the first switch 5 to the transmitter 6 and receiver 7 of the pulse signals, the first comparator 8, the second comparator 9, the first trigger 10, the allocation unit of the third period of the sine wave 11, the second trigger 12, the third trigger 13, serially connected matching device 14, third comparator 15 and counter 16, h fourth trigger 17, key device 18, serially connected time-to-digit converter 19, division unit 20, subtraction unit 21 and computing device 22, synchronization device 23, the first output of which is connected to the second inputs of keys 3 _I and 4 _I , the second output is connected to the second inputs of the keys 3 _II and 4 _II , and the third output is connected to the second inputs of the keys 3 _III and 4 _III , the logical adder 24, as well as six heaters 25 _I and 26 _I , 25 _II and 26 _II , 25 _III and 26 _III , located two in each measuring base I, II and III, with direct heat contact with their electro-acoustic transducer 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _III , connected through the second switch 27 to the temperature controller 28 and the power source 29, the control device 30, the second counter 31 and the first 32 ₁ , second 32 ₂ and third 32 ₃ devices OR.

Electro-acoustic transducers are located at the same distance L at an angle of 120 ° relative to each other and at an angle of (30-60) ° in the vertical plane.

The inputs of the first comparator 8 and the second comparator 9 are connected to the first switch 5, the output of the first comparator 8 is connected to the first input of the first trigger 10, the output of the second comparator 9 is connected to the first input of the selection node of the third period of the sine wave 11, the output of the first trigger 10 is connected to the second input of the node third selection period sinusoids 11, whose output is connected both to the second inputs of the first 32 ₁ and 32 ₃ of the third device or, the first input of the third flip-flop 13 is connected to the switch 5, and the output of the third flip-flop 13 via Clue the device 18 is connected to the first input of the second trigger 12, the output of the second trigger 12 is connected to the time slot-digit converter 19 and to the input of the synchronization device 23, the output of the first counter 16 is simultaneously connected to the second input of the key device 18 and to the first input of the fourth trigger 17, the output of which is connected to the second input of the counter 16, and the input of the matching device 14 is connected to the first input of the third trigger 13, the first, second and third inputs of the logic adder 24 are connected to the corresponding outputs of the device va sync 23, and its output is connected both to the switch 5 and the computing device 22.

The output of the counter 31 is connected to the first input of the control device 30, to the second input of which the output of the temperature controller 28 is connected, and its first output is connected to the control input of the switch 27, and the second output is simultaneously connected to the installation additional inputs of the synchronization device 23 and computing device 22 and the first inputs of all devices OR 32 ₁ , 32 ₂ and 32 ₃ , and the output of the first device OR 321 is simultaneously connected to the second inputs of the first 10, third 13 and fourth 17 triggers, the second input of the second device TWO OR 32 _{2 is} connected to the output of the first trigger 10, and its output is connected to the second input of the second counter 31, the first input of which is connected to the output of the third comparator 15, the output of the third device OR 32 _{3 is} connected to the second input of the second trigger 12.

Ultrasonic flow velocity meter works as follows.

At the beginning, the control device 30 from its second output generates a signal U30 ₂ (see FIG. 2) supplied to the installation inputs of the computing device 22 and the synchronization device 23, and through the second device OR 32 ₂ to the second input of the second counter 31, through the third device OR 32 ₃ to the second input of trigger 12 and through the first OR 32 ₁ to the second inputs of the first 10, third 13 and fourth 17 triggers, preventing the start of operation of these devices.

At the same time, with a signal U30 ₁ from its first output, the control unit 30 connects the heaters 25 _I and 26 _I , 25 _II and 26 _II , 25 _III and 26 _III through the second switch 27 to the input of the temperature controller 28, which measures the resistance of the heaters 25 _I and 26 _I , 25 _II and 26 _II , 25 _III and 26 _III , proportional to the temperature of these heaters. Since each heater 25 _I and 26 _I , 25 _II and 26 _II , 25 _III and 26 _III , has direct thermal contact with its electro-acoustic transducer 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _III , the measured the temperature is proportional (almost equal) to the temperature of these electro-acoustic transducers. The output signal U28 of the temperature controller 28, proportional to the temperature of the electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _III , is fed to the second input of the control device 30. Depending on the current value of the signal U28, proportional to the measured temperature, the device control 30 determines the necessary mode of operation of the proposed ultrasonic meter.

If the current temperature corresponds to the permissible limits, the control unit 30, holding the second switch 27 with the signal U30 ₁ in the state of measuring the temperature of the heaters 25 _I and 26 _I , 25 _II and 26 _II , 25 _III and 26 _III , stops issuing the signal U30 ₂ , allowing the operation of the synchronization device 23, the computing device 22, the first 10, second 12, third 13 and fourth 17 triggers and the second counter 31.

At the same time, a measurement cycle begins, which consists in the following.

и

, которые последовательно поступают на 1-й, 2-й и 3-й входы логического сумматора 24 и на вторые входы каждой пары ключей 3_I и 4_I, 3_II и 4_II, 3_III и 4_III, подключая пары электроакустических преобразователей 1_I и 2_I, 1_II и 2_II, 1_III и 2_III соответствующей измерительной базы I, II и III к коммутатору 5.The synchronization device 23 at its outputs sequentially, starting from the first, generates control signals U ₂₃ ,

and

which sequentially arrive at the 1st, 2nd and 3rd inputs of the logic adder 24 and at the second inputs of each key pair 3 _I and 4 _I , 3 _II and 4 _II , 3 _III and 4 _III , connecting pairs of electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _{III of the} corresponding measuring base I, II and III to the switch 5.

From the output of the logical adder 24, the signals U ₂₄ , generated in the same sequence as at the outputs of the synchronization device 23, are fed to the switch 5 and to the computing device 22, preparing them for measurements in series with each measuring base I, II, and III. Moreover, the duration of the signals from the outputs of the synchronization device 23 and the logical adder 24 corresponds to the duration of the cycle of work on radiation and reception in both directions for each measuring base I, II and III.

,

и

с выхода логического сумматора 24, поочередно подключает передатчик 6 и приемник 7 к электроакустическим преобразователям 1_I и 2_I, 1_II и 2_II, 1_III и 2_III выбранной измерительной базы I, II или III, обеспечивая работу этих электроакустических преобразователей на излучение и прием в прямом и обратном направлениях.The first switch 5 during the enable signal

,

and

from the output of the logical adder 24, alternately connects the transmitter 6 and receiver 7 to the electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _{III of the} selected measuring base I, II or III, ensuring the operation of these electro-acoustic transducers to radiation and reception in the forward and reverse directions.

In this case, the beginning of each emitted pulse U ₆ from the switch 5 starts the third trigger 13, the signal U _{13 of} which is supplied to the first input of the closed key device 18.

At the same time, the emitted pulse U _{6 is} supplied to the input of the matching device 14, which selects the sinusoidal component of the generation pulse U ₁₄ , which is fed to the input of the third comparator 15, which has a response threshold U _n = 0, which ensures accurate fixation of the beginning of the period of the sinusoidal component of the emitted signal U ₄ .

Next, the output pulses U _{15 of the} third comparator 15 are simultaneously fed to the inputs of the first counter 16, which generates an output signal U ₁₆ corresponding to the third period of the emitted pulse U ₆ , which opens the key device 18, and the second counter 31, which starts counting the periods of the emitted signal U ₆ .

The signal U ₁₃ from the output of the third trigger 13 through the open key device 18 is fed to the first input of the second trigger 12 and sets it to a single state, starting the formation of signal U _{12 of the} time interval of passage of the ultrasonic signal with a delay of 3 periods of the emitted frequency f _i , i = { 12}.

At the same time, the signal U ₁₆ from the output of the counter 16 switches the fourth trigger 17, which with its input signal U ₁₇ prohibits the operation of the first counter 16.

Next, the received signals U ₇ (see Fig. 2) are sent to the first comparator 8, which has a threshold of operation U _n > 0 and is always greater than the noise signal of the receiving channel and the second comparator 9, which has a threshold of operation U _n = 0, which ensures accurate fixing the beginning of the period of the received sinusoidal signal U ₇ .

Further, from the first comparator 8, the pulses of the signal U ₈ are supplied to the first trigger 10, the signal U _{10 of} which is supplied to the second input of the first device OR 32 ₁ and to the second input of the selection unit of the third period of the sine wave 11, which passes signal U ₉ from the second comparator 9 the third period with a threshold U _n = 0, which ensures high accuracy of the delay measurements. This signal is fed to the second input of the third device OR 32 ₃ , and from its output to the input of trigger 12 and returns the trigger to the zero state.

The signal U ₁₀ through the second device OR 32 _{2 is} supplied to the second input of the counter 31, setting it to zero and prohibiting its operation until the formation of the next pulse U ₆ .

Thus, at the output of the second trigger 12, a pulse U _{12 is formed} , the duration of which is determined only by the wind speed and the speed of ultrasound and does not depend on its frequency and the influence of the environment on it, which ensures high measurement accuracy.

At the same time, the signal U ₁₁ from the output of the selection unit of the third period of the sine wave 11 is fed to the second input of the first device OR 32 ₁ , and from its output to the second inputs of the first trigger 10, fourth trigger 17 and third trigger 13 and restores them to the initial state until the next pulse radiation in the opposite direction.

Next, the pulse U ₁₂ from the second trigger 12 is supplied to the inputs of the synchronization device 23 and the time interval-digit converter 19, in which the duration U _{12 is} converted into a digit, which, through the division unit 20, is fed to the subtraction unit 21, where the difference in the transit time of the ultrasound of the measuring base is obtained L in the figure between the forward and reverse directions. The distance L between the electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _III are equal.

,

и

по соответствующему выходу, длительность которого соответствует времени на прием и передачу туда и обратно в каждой измерительной базе I, II и III, на время Т_зад., необходимое для затухания переходных процессов в устройствах и для записи информации с выхода блока вычитания 21 в вычислительное устройство 22.Moreover, according to the decline of every second pulse U ₁₂ from the output of the second comparator 12, the synchronization device 23 stops issuing a pulse

,

and

on the corresponding output, the duration of which corresponds to the time for receiving and transmitting back and forth in each measuring base I, II and III, for the time T _ass. necessary for the attenuation of transients in the devices and for recording information from the output of the subtraction unit 21 to the computing device 22.

At the end of time T _back (see _figure 2), the synchronization device 23 generates at its next output a control signal U _23i , where i = 1, 2, 3, which connects the next measuring base I, II and III to the switch 5, repeating the described previously the process of measuring the difference in the speed of ultrasound in the appropriate base.

Since the value of the speed of sound in air does not change during the measurement, it is excluded when subtracting. The resulting speed difference is determined only by the wind drift of the pulsed ultrasonic signals in the measuring bases I, II and III and does not depend on the values of temperature, relative humidity and atmospheric pressure.

Next, the speed difference obtained in each measuring base I, II and III from the subtraction unit 21 is sequentially supplied to the computing device 22.

Electroacoustic transducers in pairs 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _III form three measuring bases located at an angle of 120 ° relative to each other and at an angle of (30-60) ° in the vertical plane, which allows for computational device 22 to calculate the horizontal speed and direction of the wind, as well as the vertical component of the wind speed from the measured values of the speed along each of the measuring bases.

In the case when the temperature of the heaters 25 _I and 26 _I , 25 _II and 26 _II , 25 _III and 26 _III , and therefore of the electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _III , will be lower permissible level, the control device 30, without removing its inhibitory signal U30 ₂ , from the second output, begins to periodically connect the heaters 25 _I and 26 _I , 25 _II and 26 _II , 25 _III and 26 _III , through the switch 27 then to the power source 29, heating them to the temperature controller 28 to control the current temperature of heaters 25 _I and 26 _I, 25 _II and 26 _II, 25 _III and 26 _III, and hence the associated eplovymi contacts respective electroacoustic transducers.

Thus, the signal U30 ₂ (see figure ₂ ), which prohibits the operation of the synchronization device 23, the computing device 22, the second counter 31 and the first 10, the third 13 and the fourth 17 triggers, will be generated until the current temperature of the heaters 25 _I and 26 _I , 25 _II and 26 _II , 25 _III and 26 _III , and therefore electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _III , allowable values.

Thus, the temperature regime of electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _{III is} stabilized, which maintains the parameters of the parameters of electro-acoustic transducers within specified limits, which prevents possible measurement failures (omissions) that occurred in the known device when the ambient temperature changes. This difference from the prototype significantly increases reliability and extends the temperature range of operation compared with the known device.

In addition, constant monitoring and control of the operating temperature of electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _III , significantly reduces the likelihood of icing on the structural elements of the measuring base where these transducers are installed, which further improves the operational characteristics of the proposed devices. However, in difficult meteorological conditions, heavy snowfall and prolonged rain may form an ice crust at the structural nodes where electro-acoustic transducers are mounted.

In this case, at the beginning of the measurement cycle in any measuring base I, II and III, where this icing occurred, the proposed device will continue to function as follows.

и

(см. фиг.3), которые последовательно поступают на 1-й, 2-й и 3-й входы логического сумматора 24 и на вторые входы каждой пары ключей 3_I и 4_I, 3_II и 4_II, 3_III и 4_III, подключая пары электроакустических преобразователей 1_I и 2_I, 1_II и 2_II, 1_III и 2_III соответствующей измерительной базы I, II и III к коммутатору 5.The synchronization device 23 at its outputs sequentially, starting from the first, generates control signals U ₂₃ ,

and

(see figure 3), which are sequentially fed to the 1st, 2nd and 3rd inputs of the logical adder 24 and to the second inputs of each key pair 3 _I and 4 _I, 3 _II and 4 _II , 3 _III and 4 _III , connecting pairs of electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _{III of the} corresponding measuring base I, II and III to the switch 5.

From the output of the logical adder 24, the signals U ₂₄ , generated in the same sequence as at the outputs of the synchronization device 23, are fed to the switch 5 and to the computing device 22, preparing them for measurements in series with each measuring base I, II, and III. Moreover, the duration of the signals from the outputs of the synchronization device 23 and the logical adder 24 corresponds to the duration of the cycle of work on radiation and reception in both directions for each measuring base I, II and III.

,

и

с выхода логического сумматора 24, поочередно подключает передатчик 6 и приемник 7 к электроакустическим преобразователям 1_I и 2_I, 1_II и 2_II, 1_III и 2_III выбранной измерительной базы I, II или III, обеспечивая работу этих электроакустических преобразователей на излучение и прием в прямом и обратном направлениях.The first switch 5 during the enable signal

,

and

from the output of the logical adder 24, alternately connects the transmitter 6 and receiver 7 to the electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _{III of the} selected measuring base I, II or III, ensuring the operation of these electro-acoustic transducers to radiation and reception in the forward and reverse directions.

In this case, the beginning of each emitted pulse U ₆ from the switch 5 starts the third trigger 13, the signal U _{13 of} which is supplied to the first input of the closed key device 18.

At the same time, the emitted pulse U _{6 is} supplied to the input of the matching device 14, which selects the sinusoidal component of the generation pulse U ₁₄ , which is fed to the input of the third comparator 15, which has a response threshold U _n = 0, which ensures accurate fixation of the beginning of the period of the sinusoidal component of the emitted signal U ₄ .

Next, the output pulses U _{15 of the} third comparator 15 are simultaneously fed to the inputs of the first counter 16, which generates an output signal U ₁₆ corresponding to the third period of the emitted pulse U ₆ , which opens the key device 18, and the second counter 31, which starts counting the periods of the emitted signal U ₆ .

The signal U ₁₃ from the output of the third trigger 13 through the open key device 18 is fed to the first input of the second trigger 12 and sets it to a single state, starting the formation of signal U _{12 of the} time interval of passage of the ultrasonic signal with a delay of 3 periods of the emitted frequency f _i , i = { 12}.

At the same time, the signal U ₁₆ from the output of the counter 16 switches the fourth trigger 17, which with its input signal U ₁₇ prohibits the operation of the first counter 16.

Further, the received signals U ₇ (see Fig. 3) are sent to the first comparator 8, which has a threshold of operation U _n > 0 and is always greater than the noise signal of the receiving channel and the second comparator 9, which has a threshold of operation U _n = 0, which ensures accurate fixing the beginning of the period of the received sinusoidal signal U ₇ .

However, in case of icing, the level of the received signal U ₇ will be significantly lower than the threshold level U _{n of the} first comparator 8, which, taking into account the previously mentioned technological reasons, was set high enough to eliminate false alarms. In this case, the output signal U ₈ from the comparator 8 will be absent and the operation of the first trigger 10 will not occur. As a result, at its output and, therefore, at the output of the second device OR 32 _{2 there} will be no signal prohibiting the operation of the second counter 31, which will continue to count the number of periods of the emitted pulse U ₆ .

When the number exceeds the threshold value N _n , the second counter 31 at the output will generate a signal U31 (see figure 3). The threshold number of periods N _{n is} proportional to the maximum expected time of occurrence of the first half-wave of the received signal U ₇ and is determined by the ratio

, где

where

L _b - the length of the measuring base,

V _{sv min} - the minimum speed of sound in air,

V _u - maximum wind speed measured along the axis of the measuring base,

f _Sv is the frequency of the ultrasonic signal.

The output signal U31 of the second counter 31 is fed to the I-th input of the control device 30, which at its second output generates a signal U30 ₂ supplied to the installation inputs of the synchronization device 23 and computing device 22, and through the first 32 ₁ , second 32 ₂ and third 32 ₃ devices OR, respectively, to the second inputs of the first 10, second 13 and fourth 17 triggers and the second counter 31, setting them to their original state and blocking their operation for the duration of the signal U30 ₂ .

At the same time, the control unit 30 enters the forced heating mode of the electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _III , connecting the heaters 25 _I and 26 _I , 25 _II and 26 _II , 25 _III and 26 _III , to power supply 28 through the switch 27 for longer periods of time (see figure 3), increasing the temperature of the heaters 25 _I and 26 _I , 25 _II and 26 _II , 25 _III and 26 _III to the maximum allowable for electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _III (or materials of construction, for example, sealants, etc.) by monitoring the current temperature and maintaining this temperature for a time determined empirically (depending on the power of the heaters, the permissible maximum temperature and weight and size characteristics of the structure where the electro-acoustic transducers 1 _I and 2 _I , 1 _II and 2 _II , 1 _III and 2 _III are installed).

Upon completion of the 1st cycle of the forced heating mode, the control unit 30 connects the signal U30 _{1 to the} heaters 25 _I and 26 _I , 25 _II and 26 _II , 25 _III and 26 _III through the switch 27 to the input of the temperature controller 28, and removes the signal from its second output U30 ₂ , allowing the start of the measurement cycle, which, as described previously, begins with the formation of signals at the output of the synchronization device 23 (see figure 3).

If the first cycle of the forced heating mode ensured the elimination of icing on the structural elements of all measuring bases, the measurement process will be carried out in full for all measuring bases I, II and III, as described previously (see figure 2), since level of the received signal U ₇ will exceed the first threshold comparator U _8, respectively, and first flip-flop 10. The output of the first flip-flop ₁₀ U 10 through the second device or the second input of the second counter 31 disables its operation and sets it zero state by preventing the formation of its output signal U31, which translates the work control unit 30 in the forced heating mode.

If the elimination of icing did not occur in at least one of the measuring bases I, II and III, then, as noted earlier, the signal level U ₇ in the measurement cycle in this measuring base will be less than the response threshold of the first comparator 8, and the signal at its output , and also at the output of the first trigger 10 will be absent.

As a result, the second counter 31 will continue to count the number of periods of the generation pulse U ₆ to the threshold value N _n .

Therefore, at the output of the second counter 31, a signal U31 is generated, which is input to the control device 30, which will start the next cycle of forced heating of electro-acoustic transducers, described earlier (see Fig. 3). If the number of forced modes in the process of elimination of icing exceeded more than 5, then the computing device 22 instead of zero information will give a malfunction signal to the control room and allowing you to take appropriate measures to restore the normal operation of the proposed device with minimal loss of time.

It should be noted that such an emergency can also occur due to contamination or sticking of objects (for example, leaves) on the working surface of electro-acoustic transducers.

However, the above features of the algorithm of the proposed device allows you to quickly identify and take measures to eliminate such situations, which was impossible during operation of the known device.

Thus, the proposed utility model allows not only to increase the reliability and expansion of the temperature range of operation, but also to increase the efficiency of its operation by adapting the algorithm of operation in difficult weather conditions, provided by the newly introduced six heaters, two in each measuring base and having direct thermal contact with appropriate electro-acoustic transducers, second switch, temperature controller, power source, device of control, a second counter and three OR devices and their interactions with other nodes of the proposed utility model, thereby improving the safety of takeoff and landing of aircraft.

INFORMATION SOURCES

1 Russian Federation, patent for invention No. 2030749, IPC: 6 G01P 5/01, 1995

2 Russian Federation, application for invention No. 93049075/28, IPC: 6 G01P 5/01, 1996

3 Russian Federation, patent for invention No. 2093835, IPC: 6 G01P 5/01, 1997

4 Russian Federation, utility model patent No. 44391, IPC: 7 G01P 5/01, 2005

5 Russian Federation, copyright certificate for the invention No. 1081544, IPC: G01P 5/00, G01F 1/66, 1984

6 Russian Federation, utility model patent No. 77975, IPC: 7 G01P 5/01, 2008

7 Russian Federation, utility model patent No. 83620, IPC: 7 G01P 5/01, 06/10/2009.

8 Russian Federation, utility model patent No. 108631, IPC: G01P 5/01, 09/20/2011

9 Russian Federation, utility model patent No. 113012, IPC: G01P 5/00, 01/27/2012 - prototype.

Claims (1)

An ultrasonic flow velocity meter containing three measuring bases, including two reversible electroacoustic transducers located at an angle of 120 ° relative to each other and at an angle of 30-60 ° in the vertical plane, as well as a switch to which a transmitter and receiver of pulse signals are connected, three a comparator, four triggers, a third-period sine wave allocation unit, a matching device, a counter, a key device, and a time-to-digital converter in series, a division unit, a subtraction unit and a computing device, as well as a synchronization device, a logical adder and six keys, two in each measuring base, while the output of the matching device is connected to the input of the third comparator, the output of which is connected to the first input of the counter, the output of the counter is simultaneously connected to the second input key device and with the first input of the fourth trigger, the output of which is connected to the second input of the counter, the inputs of the first and second comparators are connected to the switch, the output of the first comparator is connected to the first input of the first trigger, the output of the second comparator is connected to the first input of the selection node of the third sine wave, the output of the first trigger is connected to the second input of the selection node of the third sine wave, the first input of the third trigger is connected to the switch, the output of the third trigger is connected to the first input of the key device the output of which is connected to the first input of the second trigger, and the output of the second trigger is connected to the time-to-digital converter and to the synchronization device, while the first input of each key is connected to the output of the corresponding electro-acoustic transducer of its measuring base, the outputs of the keys, the inputs of which are connected to the first electro-acoustic transducers of each measuring base, are simultaneously connected to one input of the switch, the outputs of the keys, the inputs of which are connected to the second electro-acoustic transducers of each measuring base, are connected to another the switch input, the second key inputs of the first measuring base are connected to the first output of the synchronization device, the second key inputs of the second measuring base are connected to the second output of the synchronization device, the second key inputs of the third measuring base are connected to the third output of the synchronization device, the first, second and third inputs of the logical adder are connected to the corresponding outputs of the synchronization device, and its output is simultaneously connected to the switch and the computing device, characterized in that it is supplemented by six heaters, two located in each measuring base, having direct heat contact with its electro-acoustic transducer and connected through a second switch to a power source and temperature controller, also three OR devices, a control device and a second counter, the output of which is connected to the first input of the control device, to the second input of which the output of the temperature controller is connected, and its first the output is connected to the control input of the second switch, while the second output is simultaneously connected to the installation (additional) inputs of the synchronization and computation device the device and the first inputs of the three OR devices, the second inputs of the first and third OR devices connected to the output of the selection node of the third sine wave, the output of the first OR device is simultaneously connected to the second inputs of the first, third and fourth triggers, the output of the third OR device is connected to the second input the second trigger, the second input of the second device OR is connected to the output of the first trigger, and its output is to the second input of the second counter, the first input of which is connected to the output of the third comparator .

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