RU2323131C1 - Method and device for detection of icing - Google Patents

Abstract

FIELD: aeronautical engineering; detection of icing and measuring of ice thickness on flying vehicle surface.

SUBSTANCE: proposed method includes calculation of period of digitization frequency and delay time for compensation of initial phase shift, harmonic analysis of Fourier transformation, calculation of frequency and resonance Q-factor, detection of icing on basis of these data, calculation of ice thickness and rate of icing. Device proposed for realization of this method includes icing sensor with temperature sensor, transmitting converter, resonator, receiving converter and heating element, as well as processing unit with transceiver, signal processor, power amplifier, frequency synthesizer, amplifier with programmed gain factor and switch.

EFFECT: enhanced accuracy, sensitivity and noise immunity at detection of icing and measurement of ice thickness and rate of icing.

5 cl, 1 dwg

Description

The invention relates to aircraft, in particular to a technique for detecting icing and measuring the thickness of ice on the surface of an aircraft.

A known method of detecting icing and measuring the thickness of ice on the surface of an airplane [1], including the excitation of the given frequencies and voltages of ultrasonic transducers, the measurement in each transducer of the current and the angle of the phase shift relative to the excitation voltage, calculating the transmission impedance of the transducer at a given frequency, determining the frequency at which impedance has a maximum value, comparison with the reference frequency of a clean surface, calculation of the frequency increment, determination by this increment accumulated ice thicknesses, outputting the results to an indicating device and issuing an alarm if the ice thickness exceeds a predetermined limit, and a device for its implementation, comprising converters, a multiplexer, a current sensor with ADC, a voltage-controlled step-frequency generator, a processor and an indication device with an alarm .

The disadvantages of this method and device are the insufficiently high measurement accuracy, since the temperature errors of the transducers are not taken into account, the noise immunity is not high enough, since vibration errors are not taken into account, the reliability of the information is not taken into account, since natural surface contaminants, such as water, are not taken into account, in addition, their limited scope, since there is no system for dumping ice from the transducers.

The closest are the method of detecting and determining the type of deposition on the external surface of the structure [2], including the formation and transmission of an ultrasonic pulse to the contact surface of the delay line unit, automatic tuning of the gain when receiving an echo signal formed on the contact surface, measuring the amplitude and phase of the echo signal, measuring the time interval between the first peak of the echo received from the contact surface and the first peak of any additional echo, temperature measurement to compensate for temperature errors, comparing the amplitude and phase of this echo signal with the amplitude and phase of the excitation pulse or with the amplitude and phase of the reference echo signal received from a clean contact surface, determine the type of deposition from this data and calculate its thickness, and a device for its implementation, including a sensor comprising a delay line unit in which a temperature sensor, transmitting and receiving converters, and a processing unit comprising a programmable gain amplifier are installed, two amplifier with fixed gain, two keys, ADC, RAM type FIFO, microprocessor and master oscillator.

The disadvantages of this method and device are low accuracy, sensitivity and noise immunity, since the time interval by which the thickness of the ice is determined is small enough, and the accuracy of its measurement is determined by the speed of the ADC and the duration of the transmitted pulse, since at a certain thickness of ice the echo signals from the contact surface and the edge ice are formed, therefore, it is impossible to distinguish the first peak of the echo signal reflected from the edge of the ice, in addition, a limited scope, since there is no There is a system for dumping ice from the sensor, limited functionality, since the icing intensity is not determined.

The purpose of the invention is improving accuracy and noise immunity, as well as expanding the scope and functionality.

This goal is achieved by the fact that in the method of detecting icing and measuring the thickness of the ice, including the excitation of the transmitting transducer, measuring the amplitude of the output signal of the receiving transducer with automatic gain adjustment when it is received, measuring the temperature to compensate for temperature errors, according to the invention, the harmonic oscillations of the transmitting transducer are continuously excited , in addition, additionally form a sample of excitation frequencies measured over a period of the values of the output signal of the receiving transducer, the data in the sample are normalized, the noise level is controlled by them, and the Fourier transform coefficients for the first harmonic of the signal are calculated, from which the tangent of the phase shift angle of the output signal of the receiving transducer relative to the excitation signal is calculated, the tangent of the phase shift angle is search for the resonance zone by scanning the excitation frequency, and in the resonance zone by the tangent of the phase shift angle, they often capture and hold you resonance by phase-locked loop of the excitation frequency, compare the resonance frequency with the reference frequency, determine the increment of the resonance frequency, carry out tolerance control of this increment, if the increment control is negative, search for resonance frequencies with specified phase shifts by phase-locked loop of the excitation frequency, by resonance frequencies with the specified phase shifts calculate the quality factor of the resonance, by admitting control of the quality factor of the resonance determine t n deposition, in the case of ice, the thickness of the precipitated ice is calculated by incrementing the resonance frequency, and the icing intensity is calculated by the thickness of ice, giving the corresponding information, at a critical ice thickness, the heating of the sensor to reset the ice, which is controlled by the increment of the resonance frequency, is turned on, while limiting the temperature and heating time.

In addition, when measuring the amplitude of the output signal, they additionally calculate the delay time and sampling time, which compensate for the initial phase shift of the output signal of the receiving transducer relative to the excitation signal and synchronize the measurements in the sample, while automatically adjusting the gain, they additionally carry out tolerance control of the measured signal for all measurements in the sample for a given period of the excitation signal, with a negative result of the control of any measurement, decrease gain in the following measurements for a given step to a positive result for all measurements in the sample, and if this is not performed with a minimum gain, the malfunction is recorded by issuing it with the corresponding code.

And in the device for detecting icing and measuring the thickness of the ice, consisting of an icing sensor and a processing unit containing a signal processor connected to the corresponding interface bus with an amplifier with a programmable gain, to the input of which is connected the output of the icing sensor, a power amplifier and a key, according to the invention additionally a transceiver and a frequency synthesizer are introduced, the frequency synthesizer being connected to the signal processor by the interface bus, the first output of the frequency synthesizer being connected is connected with the corresponding input of the signal processor, and its second output through the power amplifier is connected to the input of the icing sensor, in addition, the input of the heating element of the icing sensor is connected via a key to the corresponding output of the signal processor, and the temperature control output of the icing sensor is connected to the signal processor by the corresponding interface bus , to the input of the ADC which is connected the output of the amplifier with a programmable gain, while the signal processor is connected to the corresponding inter eysom to the transceiver, the input / output of which is input / output device.

In addition, an icing sensor containing a receiving transducer, the output of which is the output of the icing sensor, a transmitting transducer, the input of which is the input of the icing sensor, and a temperature sensor, the output of which is the output of the temperature control of the icing sensor, additionally include a resonator in the form of an ultrasonic concentrator and a heating element, the receiving and transmitting converters, as well as the temperature sensor, are mechanically connected to the base of the resonator, and the heating elec The element is built into the resonator housing, the input of the heating element being the corresponding input of the icing sensor.

Thus, the introduction of new actions and operations, as well as new connections and elements, allowed to significantly increase accuracy, sensitivity and noise immunity due to harmonic analysis based on the Fourier transform, determining the icing intensity - to expand the functionality, and the introduction of heating to discharge the accumulated ice - the scope .

The invention is illustrated in the drawing, which shows a block diagram of a device.

A device for implementing the proposed method comprises a processing unit 1 and an icing sensor 2, while the processing unit 1 comprises a transceiver 1.1, a signal processor 1.2, a power amplifier 1.3, a programmable frequency synthesizer 1.4, a programmable gain amplifier 1.5, a key 1.6, and an icing sensor 2 contains a temperature sensor 2.1, a transmitting converter 2.2, a resonator 2.3, a receiving transducer 2.4 and a heating element 2.5.

The signal processor 1.2 is connected by the corresponding interface buses with an amplifier 1.5 with a programmable gain, to the input of which the output of the receiving converter 2.4 is connected, and a frequency synthesizer 1.4, the first output of which is connected to the corresponding input of the signal processor 1.2, and its second output through the power amplifier 1.3 is connected to the input of the transmitting converter 2.2, mechanically attached to the base of the resonator 2.3, to which the receiving converter 2.4 is also mechanically attached, and in the resonator 2.3 in triplets heater 2.5 is connected through the switch 1.6 to the output signal processor 1.2. In addition, a temperature sensor 2.1 is built into the base of the resonator 2.3 and is connected to the signal processor 1.2 by the corresponding interface bus, to the ADC input of which an amplifier output 1.5 with a programmable gain is connected, while the signal processor 1.2 is connected by the corresponding interface to the transceiver 1.1, the input / output of which is the input / output of the device.

Transceiver 1.1 may be of type MAX233, signal processor 1.2 may be of type DSP56F801, power amplifier 1.3 may be performed on a general-purpose operational amplifier, programmable frequency synthesizer 1.4 may be of type AD9834, amplifier 1.5 with programmable gain may be of type MCP6S21, key 1.6 may be made on a solid-state relay of the ASO241 type, the temperature sensor 2.1 can be of the DS18B20 type, transmitting 2.2 and receiving 2.4 transducers can be made on piezoceramic rings of the TsTS-19 type, the resonator 2.3 can be made n in the form of ultrasonic concentrator elinvarnogo alloy to the substrate which is mechanically fastened a transmitting and a receiving 2.2 2.4 converters, and temperature sensor 2.1, a resonator 2.3 2.5 embedded heater, which may be formed of a nichrome ribbon winding circuit.

This method is based on a change in the resonant frequency of the resonator 2.3 depending on the attached mass and on a change in the quality factor of the resonance depending on the viscosity of the attached mass due to damping changes and is based on the Fourier transform using a real-time digital computer.

The proposed method has two modes of operation, namely, the resonance zone search mode and the resonance frequency capture and hold mode, which include the following sequence of actions and operations:

- In the search of the resonance zone, the frequency synthesizer 1.4 is initialized, providing a sinusoidal excitation signal with a frequency f ⁱ = f _min [c ^-1 ] and a phase ψ ⁱ = 0 [rad], where f _min is the minimum frequency value, is generated at its second output is determined by the maximum permissible measured ice thickness, and at its first output - a meander for synchronization with fronts coinciding with zero values of the DAC code of the frequency synthesizer 1.4 that generates this sinusoidal signal.

- The amplifier 1.5 is initialized, providing a gain of k ⁱ = k _max , where k _max is the maximum gain, which is determined from the condition that with the maximum allowable layer of ice, that is, with a minimum level of the input signal at resonance and with interference of the maximum allowable level , provides the specified measurement accuracy.

- Calculate the sampling period T _d ⁱ for synchronization in the sample of measurements of the output signal from the receiving transducer 2.4 over the period of the excitation frequency, as T _d ⁱ = 1 / 4f ⁱ [c], and write its code in the first timer of the signal processor 1.2, then start the watchdog the timer of the signal processor 1.2 for the time t = 2 / f _min [s].

- Calculate the delay time τ ⁱ in the sample to compensate for the angle of the initial phase shift φ _{0 of the} output signal from the receiving transducer 2.4 relative to the excitation signal according to the formula τ ⁱ = (2π-φ ₀ ) / 2πf ⁱ [s] and record its code in the second timer signal processor 1.2.

- Form a sample of the output signal from the receiving transducer 2.4 over the period of the excitation frequency, for this, on the edge 0/1 of each signal from the first output of the frequency synthesizer 1.4, a second timer of the signal processor 1.2 is started, after which the ADC is first started and the first timer of the signal processor 1.2 is started , then the ADC is started and the first timer is restarted by interrupting the first timer three times, thereby delaying and synchronizing four sampling samples on the excitation signal period, except Moreover, the watchdog timer of the signal processor 1.2 is restarted on this front, and if this front is not present at time t, then a malfunction is detected by interrupting the watchdog timer by issuing it with the corresponding code.

- To interrupt the ADC of the signal processor 1.2, read its code U _j ⁱ , where j = 0, 1, 2, 3 is the measurement number in the sample.

для всех замеров в выборке, где n_max - максимальное значение кода АЦП сигнального процессора 1.2. При отрицательном результате контроля любого замера в выборке определяют коэффициент усиления в следующем замере выборки по формуле kⁱ⁺¹=kⁱ-δ₀, где δ₀ - заданный шаг. Производят вышеперечисленные действия до тех пор, пока не будет выполняться это условие для всех четырех замеров выборки. Если это условие не выполняется при kⁱ⁺¹⁼k_min, фиксируют неисправность, выдавая ее соответствующим кодом, где k_min - минимальный коэффициент усиления, который определяется из условия, что при отсутствии обледенения, то есть при максимальной амплитуде выходного сигнала на резонансе и с помехой максимально допустимого уровня, обеспечивается заданная точность измерения.- Adjustment of the gain is carried out to fulfill the conditions

for all measurements in the sample, where n _max is the maximum value of the ADC code of the signal processor 1.2. With a negative result of the control of any measurement in the sample, the gain in the next measurement of the sample is determined by the formula k ^{i + 1} = k ⁱ -δ ₀ , where δ ₀ is the given step. The above actions are performed until this condition is satisfied for all four measurements of the sample. If this condition is not satisfied when k ^{i + 1 =} k _min , the malfunction is fixed by issuing it with the corresponding code, where k _min is the minimum gain, which is determined from the condition that in the absence of icing, that is, at the maximum amplitude of the output signal at the resonance and with interference of the maximum permissible level, the specified measurement accuracy is ensured.

- Carry out the normalization, calculating the coefficient of normalization k _n ⁱ according to the formula k _n ⁱ = k _min / k ⁱ and forming the normalized data N _j ⁱ = k _n ⁱ U _j ⁱ .

- A Fourier transform is performed by a numerical method, calculating from this data the coefficients of the constant component - а ₀ ⁱ and the amplitudes - а ₁ ⁱ , in ₁ ^{i of the} first harmonic of the input signal according to the formulas

and ₀ ⁱ = (N ₀ ⁱ + N ₁ ⁱ + N ₂ ⁱ + N ₃ ⁱ ) / 4,

a ₁ ⁱ = (N ₀ ⁱ -N ₂ ⁱ ) / 2,

in ₁ ⁱ = (N ₁ ⁱ -N ₃ ⁱ ) / 2.

и

, где δ₁ - заданный допуск определяется необходимой точностью измерения, производят контроль уровня высокочастотной или импульсной помехи, при отрицательном результате контроля любого условия запускают сторожевой таймер на время t_в, где t_в определяется максимально допустимым временем действия высокочастотной помехи, и повторяют цикл измерения на данной частоте возбуждения, начиная с kⁱ=k_max, до выполнения данного условия, после чего сбрасывают сторожевой таймер, а если это условие не выполняется за это время t_в, то по прерыванию сторожевого таймера фиксируют отказ, выдавая его соответствующим кодом.- They monitor the level of interference. According to the conditions

and

, where δ ₁ - the specified tolerance is determined by the necessary measurement accuracy, the level of high-frequency or impulse noise is monitored, if the condition is negative, a watchdog timer is started for a time t _in , where t _in is determined by the maximum permissible time of high-frequency interference, and the measurement cycle is repeated given excitation frequency, starting with k ⁱ = k _max, to fulfill this requirement, then reset the watchdog timer, and if this condition is not satisfied for the time t _in, the interrupt watchman Vågå timer record failure, giving it the appropriate code.

, где δ₂ - заданный допуск определяется необходимой точностью измерения, производят контроль уровня низкочастотной помехи, при отрицательном результате контроля запускают сторожевой таймер на время t_n, где t_n определяется максимальным периодом допустимой низкочастотной помехи, и повторяют цикл измерения на данной частоте возбуждения, начиная с kⁱ=k_max до выполнения данного условия, после чего сбрасывают сторожевой таймер, а если это условие не выполняется за это время t_n, то по прерыванию сторожевого таймера фиксируют отказ, выдавая его соответствующим кодом.Otherwise, by condition

, where δ ₂ - the specified tolerance is determined by the necessary measurement accuracy, the low-frequency noise level is monitored, with a negative control result, a watchdog timer is started for a time t _n , where t _n is determined by the maximum period of the permissible low-frequency noise, and the measurement cycle is repeated at a given excitation frequency, starting with k ⁱ = k _max until this condition is met, after which the watchdog timer is reset, and if this condition is not met during this time t _n , then a failure is detected by interrupting the watchdog timer, issuing it with appropriate code.

и

, где δ₃ - заданный допуск определяется уровнем случайной составляющей входного сигнала, производят контроль наличия синхронной помехи, при положительном результате контроля обоих условий производят перепрограммирование синтезатора 1.4 частоты, обеспечивая формирование на данной частоте сигнала возбуждения с фазой ψⁱ⁺¹=π [рад], и повторяют цикл измерения, начиная с kⁱ=k_max, при повторном аналогичном результате фиксируют неисправность, выдавая ее соответствующим кодом, отрицательный результат контроля любого условия говорит об отсутствии помехи данного вида.Otherwise, under the conditions

and

, where δ ₃ - the specified tolerance is determined by the level of the random component of the input signal, the presence of synchronous interference is checked, if both conditions are positive, the frequency synthesizer 1.4 is reprogrammed, providing an excitation signal with phase ψ ^{i + 1} = π at this frequency [rad] and repeat the measurement cycle, starting with k ⁱ = k _max, with repeated similar results fix the problem, giving it the appropriate code, negative control of any conditions indicates the absence of this type of interference.

- Repeat the measurement cycle, at a given excitation frequency, the specified number of clock cycles, which is determined by the cavity time constants 2.3, fix the values f ⁱ , ψ ⁱ and calculate the average value A ₁ ⁱ and B ₁ ^{i of the} coefficients a ₁ ⁱ and ₁ ⁱ , forming the corresponding elements M arrays _A ^i, _B M ^i, M _f ⁱ and M _ψ ^i.

- performs scanning drive frequency, producing 1.4 reprogramming the synthesizer frequency and providing issuing the next excitation frequency f ^{i + 1} = f ⁱ + δ ₄ [s ^-1] and phase ψ ^{i + 1} = 0 [rad], where δ ₄ - Setpoint the increments are determined by the cavity time constants 2.4, and the measurement cycle is repeated at a given excitation frequency, starting from k ^{i + 1} = k _max , forming the following array elements and so on up to f ^{i + 1} = f _max .

, где δ₅ - заданный допуск определяется постоянными времени резонатора 2.3, при отрицательном результате контроля исключаются элементы массива, соответствующие зафиксированной частоте возбуждения fⁱ, и определяется следующее значение частоты возбуждения fⁱ⁺¹, при которой коэффициент B₁ ⁱ⁺¹ имеет максимальное значение и так далее до получения положительного результата, после чего переходят в следующий режим работы.- Search for the resonance zone by processing the obtained arrays, determining f ⁱ and ψ ⁱ at which the coefficient B ₁ ⁱ has the maximum value, while checking the phase angle of the output signal of the receiving transducer 2.4 relative to the excitation signal, calculating the value of the tangent of the phase shift angle formula tgφ ⁱ = a ₁ ⁱ / B ⁱ ₁ and controlling it to get into resonance zone to fulfill the conditions

, where δ ₅ - the specified tolerance is determined by the time constants of the resonator 2.3, with a negative control result, array elements corresponding to the fixed excitation frequency f ⁱ are excluded, and the following value of the excitation frequency f ^{i + 1} is determined, at which the coefficient B ₁ ^{i + 1} has the maximum value and so on until a positive result is obtained, after which they switch to the next mode of operation.

, где δ₆ - заданный допуск определяется необходимой точностью измерения, при этом на такте τⁱ работы дополнительно производят следующее:In the mode of capturing and holding the resonance frequency, the frequency synthesizer 1.4 is reprogrammed, providing them with an excitation signal with the frequency f ⁱ defined in the previous paragraph and a phase shift ψ ⁱ , similarly performing the above operations, they obtain the corresponding coefficients A ₁ ⁱ and B ₁ ⁱ and calculating a current value of the phase shift tgφ ^i, which is performed by phase lock the excitation frequency, the sign of the phase shift tgφ ⁱ determining the direction and forming the following meanings wHO frequency uzhdeniya f ^{i + 1,} the proportional control law to the condition

Where δ ₆ - predetermined tolerance determined by the required accuracy of measurement, the clock cycle τ ⁱ for further work produced as follows:

- Carry out a given number of measurements of the resonance frequency, which is determined by the required measurement accuracy.

- Calculate the average value F ^{i of} the resonance frequency, and the temperature correction t _i ° [° C] of the sensor 2.1 calculates the temperature correction and compensates the temperature error of the average F ⁱ value of the resonance frequency.

- Compare the resonance frequency with the reference frequency, calculate the increment Δ ⁱ _{F of} the resonance frequency according to the formula Δ ⁱ _F = F ₀ ⁱ -F ⁱ [c ^-1 ], where F ₀ ⁱ is the reference resonance frequency of the clean sensor.

- Control the sign of Δ ⁱ _F , with a negative value of the reference resonance frequency, assign the value F ₀ ^{i + 1} = F ⁱ , since the mass attached to the resonator 2.3 can only reduce the resonance frequency.

- If the sign is positive, Δ ⁱ _{F is} controlled according to the condition Δ ⁱ _F ≤ δ ₇ , where δ ₇ is the specified tolerance determined by the required measurement accuracy, a positive result indicates the absence of contamination.

- If the control result of the above conditions is negative, the temperature t ₁ ° ≤t _i ° ≤t ₂ ° is controlled, where t ₁ °, t ₂ ° are the temperatures of the possible icing zone, if the control is negative, the pollution is fixed and the reference resonance frequency is assigned the value F ₀ ^{i +1} = F ⁱ .

- If the control result of the above condition is positive, they search for resonance frequencies with phase shifts of 45 ° and 45 °, forming the following value of the excitation frequency f ^{i + 1} according to the proportional control law until the conditions for ensuring these phase shifts -1-δ ₆ ≤tgφ ⁱ ≤-1 + δ ₆ and, accordingly, 1-δ ₆ ≤tgφ ⁱ ≤1 + δ ₆ , assigning the resonant frequency with a phase shift of 45 ° to f ₁ , and the resonant frequency with a phase shift of 45 ° to f ₂ .

- Alternately program a frequency synthesizer 1.2 to generate excitation frequencies with frequencies f ⁱ = f ₁ or f ⁱ = f ₂ and, making at each frequency a given number of measurements, which is determined by the required measurement accuracy, calculate their average values F ₁ ⁱ and F ₂ ⁱ respectively.

- The temperature of the sensor 2.1 compensates for temperature errors of the average values of F ₁ ⁱ and F ₂ ⁱ .

- Calculate the frequency F ⁱ resonance according to the formula F ⁱ = (F ₁ ⁱ + F ₂ ⁱ ) / 2 [s ^-1 ].

- Calculate the quality factor q ^{i of the} resonance according to the formula q ⁱ = F ⁱ / (F ₁ ⁱ -F ₂ ⁱ ).

- Controlling the fulfillment of the condition q ₁ <q ⁱ <q ₂ , where q ₁ and q ₂ are the resonance Q factors of the resonator 2.3 when a specified amount of water and ice are deposited on it, respectively, are determined by a given sensitivity to the attached mass, a positive result indicates that the resonator 2.3 the mixture of water and ice and the reference resonance frequency is assigned the value F ₀ ^{i + 1} = F ₀ ⁱ .

- If the control result of the above condition is negative, the fulfillment of the condition q ⁱ > q _{2 is} controlled, a negative result indicates the deposition of water on the resonator 2.3.

- A positive result of the control of the above condition indicates the deposition of ice on the resonator 2.3, while the thickness of the ice is calculated by the formula h ⁱ = k _h Δ ⁱ _F + h ₀ [m], where k _h , h ₀ are the conversion constants.

- Calculate the icing intensity according to the formula I ⁱ = (h ⁱ -h ^i-1 ) / τ [m / s], where τ is the specified clock cycle, and give a signal about the presence of icing, information about the ice thickness and icing intensity.

- The thickness of the ice is controlled by checking that the conditions h ⁱ ≥h ^{k are} satisfied, where h ^k is the maximum permissible layer of ice, with a positive result, including heating the sensor to discharge ice, which is controlled by the increment of the resonance frequency, while limiting the temperature and heating time.

A device that implements this method works as follows. When the power is turned on, the signal processor 1.2 is initialized, that is, the corresponding program starts, which resets the corresponding registers, resets the RAM memory cells to zero, maskes the corresponding interrupts, programs the I / O ports and control registers, and the like.

Next, the signal processor 1.2 initializes the frequency synthesizer 1.4, writing into its control registers and frequency and phase registers the corresponding codes on the corresponding communication lines of the interface bus, and a sinusoidal excitation frequency signal is generated at the second output of the frequency synthesizer 1.2, which is fed to the input through the power amplifier 1.3 transmitter 2.2, and at its first output a meander is formed with fronts corresponding to transitions through a zero sinusoidal signal, and this meander according to the corresponding Communications Research Institute supplied to the corresponding input signal processor 1.2, synchronize the measurement process to the front 0/1 of the meander by running embedded ADC at certain times. In addition, the signal processor 1.2 monitors the period of this meander using a watchdog timer, issuing a corresponding malfunction code if it is absent, then the signal processor 1.2 initializes the amplifier 1.5 with a programmable gain, the input of which is connected to the output of the receiving transducer 2.4, and the output through the corresponding communication line connected to the input of the ADC of the signal processor 1.2, writing into it the corresponding codes through the communication lines of the interface bus and setting the maximum gain, according to le signal processor 1.2 which proceeds to initialize the temperature sensor 2.3, similar to writing it over the bus interface corresponding codes, thereby completing the initialization of the whole device. After that, the signal processor 1.2 starts to execute the program that implements the above method, outputting the results via the RS-232 interface through the transceiver 1.1 to the output of the device.

The message format on the RS-232 interface is as follows:

- the first byte is the control byte, where the corresponding bits indicate signs of icing, pollution, deposition of water, in addition, the codes of the detected malfunctions;

- second byte - byte of ice thickness;

- third byte - icing intensity byte;

- the fourth byte is the low byte of the temperature value;

- fifth byte - high byte of the temperature value;

- sixth byte - checksum byte.

Thus, the introduction of new actions and operations, as well as new connections and elements, allowed us to significantly increase the accuracy, sensitivity and noise immunity both by measuring at the maximum possible input signal and by harmonic analysis based on the Fourier transform, determining the icing intensity - expand the functional opportunities, and the introduction of heating to dump the accumulated ice is a field of application.

Information sources

1. US patent for the invention No. 6731225 B2, IPC G08B 21/00, 04/04/2004.

2. US patent for the invention No. 5507183, IPC G01N 29/20, 04.16.1996 (prototype).

Claims (5)

1. A method of controlling icing, including excitation of the transmitting transducer, measuring the amplitude of the output signal of the receiving transducer with automatic gain adjustment when it is received, measuring temperature to compensate for temperature errors, characterized in that the harmonic oscillations of the transmitting transducer are continuously excited, and a sample of frequencies measured over a period is generated excitation values of the output signal of the receiving transducer, normalize the data in the sample, They control the level of interference and calculate the Fourier transform coefficients for the first harmonic of the signal, which calculate the values of the tangent of the phase shift of the output signal of the receiving transducer relative to the excitation signal, by the tangent of the angle of the phase shift, search for the resonance zone by scanning the excitation frequency, and in the resonance zone the tangent of the phase shift angle capture and hold the resonance frequency by phase-locked loop excitation frequency, compare the frequency resonance with the reference frequency, determine the increment of the resonance frequency, carry out tolerance control of this increment, if the increment control is negative, search for resonance frequencies with predetermined phase shifts by phase-locked loop excitation frequencies, calculate the resonance quality factor from resonance frequencies with predetermined phase shifts, and allow quality control resonance and determine the type of deposition, in the case of ice, the thickness of the deposited is calculated by incrementing the resonance frequency da, and the thickness of the ice on the calculated intensity icing work per cycle and output the appropriate information, a critical ice thickness sensor includes heating to reset the ice, which is controlled by the increment resonance frequency, wherein the limiting temperature and the heating time. 2. The method according to claim 1, characterized in that when measuring the amplitude of the output signal of the receiving transducer, they additionally calculate the delay time and sampling time, which compensate for the initial phase shift of the output signal of the receiving transducer relative to the excitation signal and synchronize the measurements in the sample. 3. The method according to claim 1, characterized in that when the gain is automatically adjusted, tolerance control of the measured signal is additionally carried out for all measurements in the sample at a given period of the excitation signal, if the result of any measurement is negative, the gain in the following measurements is reduced by a given step to a positive result for all measurements in the sample, if this is not performed with a minimum gain, fix the fault with the appropriate code. 4. A device for controlling icing, consisting of an icing sensor and a processing unit containing a signal processor connected to an amplifier with a programmable gain by a corresponding interface bus, to the input of which an icing sensor output is connected, a power amplifier and a key, characterized in that in the processing unit additionally, a transceiver and a frequency synthesizer are introduced, moreover, the frequency synthesizer is connected to the signal processor by the interface bus, the first output of the frequency synthesizer is connected to the input signal of the signal processor, and its second output through the power amplifier is connected to the input for exciting the icing sensor, the input for heating the icing sensor is connected through a key to the corresponding output of the signal processor, and the temperature control output of the icing sensor is connected to the input processor by the corresponding interface bus The ADC of which is connected to the output of the amplifier with a programmable gain, while the signal processor is connected by a corresponding interface to the receiver a sensor whose input / output is the input / output of the device. 5. The device according to claim 4, characterized in that in the icing sensor containing a receiving transducer, the output of which is the output of the icing sensor, a transmitting transducer, the input of which is an input for exciting the icing sensor, and a temperature sensor, the output of which is an output of the sensor temperature control icing, additionally introduced a resonator in the form of an ultrasonic concentrator and a heating element, the receiving and transmitting transducers, as well as a temperature sensor mechanically connected s to the base of the cavity, and a heating element is built into the resonator body, wherein the heating element input is the input for heating icing sensor.