RU2613037C1 - Calculator of range rate of moving object - Google Patents

Abstract

FIELD: measurement technology.

SUBSTANCE: calculator of radial velocity of the moving object comprises a delay unit, a complex conjugation block complex multiplication, averaging unit, a phase calculation unit correcting measurement limits, a multiplier, a key calculation unit module, the first memory unit, a control unit, a threshold unit, a second memory unit , the timing, the first and second two-channel keys, additional averaging unit, an additional delay unit, an additional block of complex conjugation and additional complex multiplication unit connected in a certain way and performing between-period correlation processing raw samples.

EFFECT: improving the accuracy of measuring the speed due to the smaller number of functional transformation and expansion of the range of uniquely measured radial velocity while maintaining a clear distance measurement.

11 dwg

Description

The invention relates to computer technology and is intended for calculation based on the correlation principle of the radial velocity of a moving object; can be used in automated air traffic control systems to detect and measure the speed of aircraft.

Known multi-channel non-tracking filter meter [1], each channel of which contains a matched filter and detector connected in series, the outputs of the channels are combined by a resolver. However, this device has a low measurement accuracy.

A device for processing a signal of a moving target [2] is also known, which contains series-delayed blocks, a complex number multiplier, and a subtractor. However, this device has low accuracy and ambiguity of measurement.

Closest to the invention is a Doppler signal meter [3], selected as a prototype, comprising a delay unit, a complex conjugation unit, a complex multiplication unit, an averaging unit, a phase calculation unit, a multiplier, a key, a module calculation unit, a first memory unit, a control unit , a threshold block, a second memory block, and a clock generator. However, this device has ambiguity and low measurement accuracy due to the presence of a large number of functional transformations.

The problem solved in the invention is to expand the range of unambiguously measured radial velocity and increase the accuracy of the measurement due to the smaller number of functional transformations when using joint processing of non-equidistant pulsed radio signals.

To solve the problem in the calculator of the radial speed of a moving object, containing a delay unit, complex conjugation unit, complex multiplication unit, averaging unit, phase calculation unit, measurement limits correction unit, multiplier, key, first memory unit, module calculation unit, control unit, the threshold block, the second memory block and the sync generator, the first and second two-channel keys, an additional averaging block, an additional delay block, an additional complex pairing block, and additional Yelnia complex multiplication unit.

Additional blocks entered in the proposed calculator are known. Thus, the delay unit, the complex conjugation unit, and the complex multiplication unit connected together allow one to isolate the Doppler phase incursion for the interval between adjacent pulses. However, the joint use of the delay unit, the complex conjugation unit, the complex multiplication unit, the first and second two-channel keys, the control unit, the additional delay unit, the additional complex conjugation unit and the additional complex multiplication unit is not known. The connections of the first and second two-channel keys with the complex multiplication unit and the control unit, the averaging unit with the first two-channel key and the additional delay unit, the additional averaging unit with the second two-channel key and the additional complex conjugation unit, the additional complex multiplication unit with the additional delay unit and the additional are new complex conjugation unit, an additional complex multiplication unit with a phase calculation unit, a limit correction unit, and measurement and a module calculation unit, which provides an extension of the range of unambiguously measured radial velocity and increased measurement accuracy due to fewer functional transformations when using joint processing of radio-pulse signals. The connections between the sync generator and all the blocks of the calculator of the radial speed of a moving object provide a coordinated processing of non-equidistant sequence of radio signals.

Comparison with the technical characteristics known from published sources of information shows that the claimed solution has novelty and has an inventive step.

The claimed solution is technical in nature, feasible, reproducible and, therefore, is industrially applicable.

In FIG. 1 is a structural electrical diagram of a calculator of the radial velocity of a moving object; in FIG. 2 - delay unit; in FIG. 3 - block complex conjugation; in FIG. 4 - block complex multiplication; in FIG. 5 - averaging unit; in FIG. 6 - phase calculation unit; in FIG. 7 - block correction limits of measurement; in FIG. 8 - character assignment unit; in FIG. 9 - module calculation unit, in FIG. 10 - two-channel key; in FIG. 11 - control unit.

The radial velocity calculator of a moving object (Fig. 1) contains a delay unit 1, complex conjugation unit 2, complex multiplication unit 3, averaging unit 4, phase calculation unit 5, measurement limits correction unit 6, multiplier 7, key 8, first memory unit 9 , control unit 10, module calculation unit 11, threshold unit 12, second memory unit 13, clock generator 14, first two-channel key 15, second two-channel key 16, additional averaging unit 17, additional delay unit 18, additional complex pairing and add-on unit 19 an additional complex multiplication unit 20, while the outputs of the delay unit 1 are connected to the inputs of the complex conjugation unit 2, the outputs of which are connected to the first inputs of the complex multiplication unit 3, the second inputs of which are combined with the inputs of the delay unit 1, the output of the first memory unit 9 is connected to the first input a multiplier 7, the output of which is connected to the input of the key 8, the output of the threshold block 12 is connected to the control input of the key 8, the first input of the threshold block 12 is connected to the output of the second memory block 13, the outputs of the complex multiplication block 3 I am connected to the combined inputs of the first 15 and second 16 two-channel keys, the control inputs of which are connected respectively to the first and second outputs of the control unit 10, the outputs of the first two-channel key 15 are connected to the inputs of the averaging unit 4, the outputs of which are connected to the inputs of the additional delay unit 18, the outputs the second two-channel key 16 is connected to the inputs of the additional block 17 averaging, the outputs of which are connected to the inputs of the additional block 19 complex pairing, the outputs of the additional block 18 back The arms are connected to the first inputs of the additional complex multiplication unit 20, the second inputs of which are connected to the outputs of the additional complex conjugation unit 19, the outputs of the complex multiplication unit 20 are connected to the combined inputs of the phase calculation unit 5, the second and third inputs of the measurement limits correction unit 6, and the calculation unit 11 module, the output of block 11 calculating the module is connected to the second input of the threshold block 12, the output of block 6 correction of the limits of measurement is connected to the second input of the multiplier 7, the output of the clock Ora 14 is connected to the clock inputs of the delay unit 1, complex conjugation unit 2, complex multiplication unit 3, averaging unit 4, phase calculation unit 5, measurement limits correction unit 6, multiplier 7, key 8, first memory unit 9, module calculation unit 11, threshold block 12, second memory block 13, first 15 and second 16 two-channel keys, additional averaging block 17, additional delay unit 18, additional complex conjugation block 19 and additional complex multiplication block 20, the inputs being calculated ator radial velocity of the moving object 1 are input delay unit and first and second outputs - key respectively output 8 and an output of the threshold unit 12.

The delay unit 1 and the additional delay unit 18 (Fig. 2) contain two digital delay lines 21, the inputs of the delay units are the inputs of the digital delay lines 21, the outputs of which are the outputs of the delay units.

The complex conjugation unit 2 and the additional complex conjugation unit 19 (Fig. 3) comprise an inverter 22, the first input of the complex conjugation block is its first output, the second input is the inverter input, the output of which is the second output of the complex conjugation block.

The complex multiplication block 3 and the additional complex multiplication block 20 (Fig. 4) contain two channels (I, II), each of which includes the first multiplier 23, the second multiplier 24 and the adder 25 connected in series, the output of the first multiplier 23 of one channel is connected to the second the input of the adder 25 of the other channel, and the first and second inputs of the complex multiplication block, respectively, are the combined first inputs of the first and second multipliers 23, 24 of each channel, the combined second inputs of the first Ithel 23 and the combined second inputs of the second multipliers 24 and the output unit are complex multiplication outputs of adders 25 of each of the channels.

Block 4 averaging and additional block 17 averaging (Fig. 5) contain two channels (I, II), each of which consists of (N-3) / 2 series-connected digital delay lines 26 and (N-3) / 2 series-connected adders 27, the inputs of the averaging block are the combined inputs of the first delay line 26 and the first adder 27 of each channel (I, II), and the output of the k-th [k = 1 ... (N-3) / 2] delay line 26 is connected to the second input of the k-th [k = 1 ... (N-3) / 2)] adder 27 of each channel (I, II), the outputs of the averaging block are the outputs of the [(N-3) / 2] -x adders 27.

The phase calculation unit 5 (Fig. 6) contains a series divider 28 and a functional converter 29, the inputs of the phase calculator are the inputs of the divider 28, and the output of the phase converter 29 is the output of the functional converter 29.

Block 6 correction of the limits of measurement (Fig. 7) contains sequentially connected modular block 30, the adder 31, the block 32 of the assignment of the sign, the first key 33 and the adder 34, while the first input of the block 6 correction of the limits of measurement through the second key 35 is connected to the second input of the adder 34, the output of the memory unit 36 is connected to the second input of the adder 31, the second input of the measurement range correction unit is connected to the control inputs of the first 33 and second 35 keys, the second input of the character assignment unit 32 is the third input of the measurement range correction unit, course of the adder 34 is its output.

The character assignment unit 32 (FIG. 8) contains multiplication units 37, 40, a memory unit 38 and a limiter 39, the second input of the character assignment unit being the first input of the multiplication unit 37, the second input of which is connected to the output of the memory unit 38, the output of the multiplication unit 37 connected to the input of the limiter 39, the output of which is connected to the first input of the multiplication unit 40, the second input of which is the first input of the character assignment unit, the output of the character assignment unit is the output of the multiplication unit 40.

The module calculation unit 11 (Fig. 9) contains two multiplication units 41, an adder 42 and a square root extraction unit 43, the inputs of the module calculation unit are the inputs of the multiplication units 41, the outputs of which are connected to the first and second inputs of the adder 42, the output of which is connected to the input a square root extraction unit 43, the output of which is the output of a module calculation unit.

The first 15 and second 16 two-channel keys (Fig. 10) contain two keys 44, the inputs of the two-channel keys are the inputs of the keys 44, the outputs of which are the outputs of the two-channel keys.

The control unit 10 (Fig. 11) contains a trigger 45 and an element HE 46, the input of the control unit is the input of the trigger 45, the output of which is connected to the input of the element HE 46, the first output of the control unit 10 is the output of the trigger 45, and the second output is the output of the element NOT 46.

The calculator of the radial velocity of a moving object works as follows.

In the inventive calculator, a non-equidistant coherent-pulse sequence of N radio signals with alternating repetition periods T ₁ and T _{2 is} processed, with Τ ₁ -Τ ₂ = ΔT. When radio signals are reflected from a moving target, their carrier frequencies in the corresponding periods acquire Doppler phase shifts

,

,

,

,

,

,

- доплеровская частота, ν_r - радиальная скорость цели,

- несущая частота радиосигналов, с - скорость распространения радиоволн.Where

is the Doppler frequency, ν _r is the radial velocity of the target,

- carrier frequency of radio signals, s - propagation velocity of radio waves.

The radio signals reflected from the target are fed to the input of the receiver, in which they are amplified, are transferred to the video frequency in quadrature phase detectors, and then undergo analog-to-digital conversion (the corresponding blocks in Fig. 1 are not shown). At the input of the calculator in one element of range resolution, digital readings of the complex envelope are received

, k=1 … N,

, k = 1 ... N,

where u _1k , u _2k are the digital codes of the real and imaginary parts of the samples U _k .

). Далее в блоке 3 комплексного умножения (фиг. 4) реализуется попарное умножение отсчетов в соответствии с алгоритмомThe input samples U _{k of the} calculator (Fig. 1) in the delay unit 1 (Fig. 2) under the control of the synchronizing pulses generated by the sync generator 14 are alternately delayed by the intervals T ₁ and T ₂ , which ensures synchronization of the subsequent complex multiplication of the samples in range. The sync generator 14 is controlled by the pulses of the radar synchronizer (not shown in Fig. 1), following alternately at intervals T ₁ and T ₂ . In block 2 complex conjugation (Fig. 3) is a complex conjugation of the delayed reference (

) Further, in block 3 of complex multiplication (Fig. 4), pairwise multiplication of samples is implemented in accordance with the algorithm

раздельно для каждого интервала T₁ и Т₂ соответственно через первый 15 и второй 16 двухканальные ключи раздельно поступают в блок 4 усреднения и в дополнительный блок 17 усреднения (фиг. 5). Поочередная коммутация первого 15 и второго 16 двухканального ключей осуществляется импульсами соответственно с первого и второго выходов блока 10 управления, синхронизируемого также импульсами синхронизатора радиолокатора.Pairwise products (correlations)

separately for each interval T ₁ and T _2, respectively, through the first 15 and second 16 two-channel keys are separately received in block averaging 4 and in an additional block 17 averaging (Fig. 5). Alternate switching of the first 15 and second 16 two-channel keys is carried out by pulses, respectively, from the first and second outputs of the control unit 10, synchronized also by the pulses of the radar synchronizer.

In block 4 averaging (Fig. 5), using delay lines 26 for the interval T ₁ + T ₂ and adders 27 in each range resolution element, coherent summation (accumulation) _of pairwise products (correlations) corresponding to the interval T _{1 is} performed along the azimuth. As a result, at the output of block averaging 4 for odd N, a value proportional to the correlation moment of samples corresponding to the interval T _{1 is formed} , the quantity

In the additional averaging block 17 (Fig. 5), a similar summation _of pairwise correlations corresponding to the T ₂ interval is performed, which leads to the formation at its output proportional to the correlation moment of the samples corresponding to the T ₂ interval,

:

:

The value of Y ₁ at the output of the averaging unit 4 (FIG. 5) in time precedes the value of Y ₂ by the interval T ₂ , which is compensated by the corresponding delay Y ₁ in the additional delay unit 18 (FIG. 2). In the additional block 19 complex conjugation (Fig. 3) the sign of the imaginary part of the value Y _{2 is} inverted.

одновременно поступают соответственно на первые и вторые входы дополнительного блока 20 комплексного умножения (фиг. 4), на выходе которого вычисляется величинаValues Y ₁ and

simultaneously arrive, respectively, at the first and second inputs of the additional complex multiplication unit 20 (Fig. 4), at the output of which the value is calculated

The values ν ₁ and ν ₂ are supplied to the corresponding inputs of the phase calculation unit 5 (Fig. 6), where, based on the division unit 28 and the arc tangent functional converter 29, an estimate is calculated

.

.

происходят в блоке 6 коррекции пределов измерения (фиг. 7) и зависят от знака ν₁. При ν₁>0 открыт второй ключ 35, и оценка

через сумматор 34 непосредственно поступает на выход блока коррекции пределов измерения. При ν₁<0 открыт первый ключ 33, а второй ключ 35 закрыт. При этом в модульном блоке 30 образуется

, вычитаемый в блоке 31 из величины π, поступающей от блока 36 памяти. Полученной разности в блоке 32 присваивается знак величины ν₂.Subsequent Assessment Conversions

occur in block 6 correction of the limits of measurement (Fig. 7) and depend on the sign of ν ₁ . For ν ₁ > 0, the second key 35 is open, and the estimate

through the adder 34 directly enters the output of the correction unit of the measurement limits. When ν ₁ <0, the first key 33 is open, and the second key 35 is closed. Thus in the modular block 30 is formed

subtracted in block 31 from the value of π coming from the block 36 of the memory. The resulting difference in block 32 is assigned the sign of ν ₂ .

, поступающей с выхода блока 31 на первый вход блока 32 присвоения знака, т.е. на второй вход блока 40 умножения.Block 32 character assignment (Fig. 8) works as follows. The value ν ₂ [relation (1)] is supplied to the second input of the sign-assigning unit, where in the multiplication unit 37 it is multiplied by a constant factor from the memory unit 38 in order to scale and further limit the limiter 39 to a level of ± 1. Thus, after the restriction, the value at the output of the limiter 39 has the meaning of the sign of the quantity ν ₂ , which, arriving at the first input of the multiplication unit 40, is assigned the difference

coming from the output of block 31 to the first input of the character assignment block 32, i.e. to the second input of the multiplication block 40.

The operations considered allow, in block 5 of the phase calculation, first to find an estimate of the Doppler phase shift located in the interval [-π / 2, π / 2], and then using block 6 to correct the measurement limits, expand the limits of its unambiguous measurement to the interval [-π, π ] according to the algorithm

на весовой коэффициент а, хранящийся в первом блоке 9 памяти, что позволяет найти однозначную оценку радиальной скорости в соответствии с выражениемThe multiplier 7 (Fig. 1) multiplies the found phase shift estimate

by the weight coefficient a stored in the first memory block 9, which allows one to find an unambiguous estimate of the radial velocity in accordance with the expression

- весовой коэффициент.Where

- weight coefficient.

To reduce the likelihood of the computer working by noise, it excludes the issuance of the obtained estimate for output in the absence of a signal reflected from the target. In block 11, the calculation of the module (Fig. 9) calculates the value

which is supplied to the second input of the threshold block 12, which compares with the threshold level z ₀ recorded in the second memory block 13. If the threshold level z ₀ is exceeded, then the output of the threshold block 12 receives a permission signal for passing the calculation result from the output of the multiplication block 7 through the key 8 to the first output of the calculator of the radial velocity of a moving object. Otherwise, key 8 is open. In addition, the signal from the output of the threshold block 12, which is the second output of the calculator of the radial speed of a moving object, can be used to read other coordinates of the target, for example range.

The synchronization of the calculator of the radial speed of a moving object is carried out by applying to all blocks of the inventive calculator a sequence of synchronizing pulses generated by the synchronizer 14 (Fig. 1) with a repetition period t _k determined from the condition of the required range resolution.

и с учетом

для максимально возможной скорости движущегося объекта ν_{r max} выбрать интервал

, то во всем диапазоне реальных скоростей движущегося объекта может быть осуществлено их однозначное измерение. При этом сохраняется однозначность измерения дальности, которая обеспечивается соответствующим выбором меньшего периода повторения импульсов Т₂.The achievement of the technical result is explained as follows. In the known device (prototype), the initial Doppler phase shifts ϕ ₁ and ϕ ₂ , by which the value Δϕ = ϕ ₁ -ϕ _{2 is} calculated, have a single-valued measurement interval [-π, π], which corresponds to a single-valued measurement Doppler frequency interval [-1 / 2T ₁ ], 1 / 2T ₁ ]] (by the value of the larger period T ₁ ). In the proposed device, the value of Δϕ is measured directly, which corresponds to the interval of uniqueness of Doppler frequencies [-1 / 2ΔT, 1 / 2ΔT]. Moreover, the interval of unambiguous measurement of the Doppler frequency and, consequently, the radial velocity expands by T ₁ / ΔT times, which corresponds to the solution of the problem of the invention. If in accordance with the condition

and given

for the maximum possible speed of a moving object ν _{r max} choose the interval

, then in the entire range of real speeds of a moving object, their unambiguous measurement can be carried out. This preserves the uniqueness of the range measurement, which is ensured by the appropriate choice of a shorter pulse repetition period T ₂ .

The errors of the separate calculation of ϕ ₁ and ϕ ₂ due to functional transformations are statistically independent. As a result, the error (dispersion) of the difference ϕ ₁ -ϕ ₂ = Δϕ is doubled. In the proposed calculator, when directly calculating Δϕ, such a doubling is absent, which corresponds to an increase in the measurement accuracy.

Thus, the calculator of the radial velocity of a moving object allows you to expand the range of unambiguously measured radial velocity and improve the accuracy of the measurement due to the smaller number of functional transformations when using the proposed joint processing of non-equidistant coherent-pulse radio signals.

Bibliography

1. Shirman Y.D. and Manzhos V.N. The theory and technique of processing radar information against the background of interference. - M .: Radio and communication. - 1981. - S. 204. - Fig. 14.2.

2. Patent No. 63-49193 (Japan), IPC G01S 13/52. Radar device for detecting a moving target / K.K. Toshiba. Publ. 10/03/1988. - Inventions of the countries of the world. - 1989. - Issue 109. - No. 15. - S. 52.

3. Patent No. 2017167 (Russia), IPC G01S 13/58. Detector-meter of Doppler signals / D.I. Popov, C. B. Gerasimov and E.N. Mataev. Publ. 07/30/1994. - Inventions. - 1994. - No. 14. - S. 121.

Claims (1)

A radial velocity calculator of a moving object, comprising a delay unit, a complex conjugation unit, a complex multiplication unit, an averaging unit, a phase calculation unit, a measurement range correction unit, a multiplier, a key, a first memory unit, a control unit, a module calculation unit, a threshold unit, a second unit memory and a clock generator, while the outputs of the delay unit are connected to the inputs of the complex conjugation unit, the outputs of which are connected to the first inputs of the complex multiplication unit, the second inputs of which are combined with the input by the delay block, the output of the first memory block is connected to the first input of the multiplier, the output of which is connected to the key input, the output of the threshold block is connected to the control input of the key, the first input of the threshold block is connected to the output of the second memory block, the output of the clock generator is connected to the sync inputs of the delay block, block complex conjugation, complex multiplication block, averaging block, phase calculation block, multiplier, key, module calculation block, first and second memory blocks, correction unit for measurement limits and threshold th block, characterized in that the first and second two-channel keys, an additional averaging block, an additional delay block, an additional complex conjugation block and an additional complex multiplication block are introduced, while the outputs of the complex multiplication block are connected to the combined inputs of the first and second two-channel keys, control inputs which are connected respectively to the first and second outputs of the control unit, the outputs of the first two-channel key are connected to the inputs of the averaging unit, the outputs of which are dined with the inputs of the additional delay unit, the outputs of the second two-channel key are connected to the inputs of the additional averaging unit, the outputs of which are connected to the inputs of the additional complex conjugation unit, the outputs of the additional delay unit are connected to the first inputs of the additional complex multiplication unit, the second inputs of which are connected to the outputs of the additional complex unit interfaces, outputs of the additional complex multiplication block are connected to the inputs of the phase calculation unit, the calculation unit module, the second and third inputs of the block for the correction of the limits of measurement, the output of which is connected to the second input of the multiplier, the output of the unit for calculating the module is connected to the second input of the threshold block, the output of the clock is connected to the clock inputs of the first and second two-channel keys, an additional averaging block, an additional delay block an additional block of complex conjugation and an additional block of complex multiplication, and the inputs of the block are the inputs of the calculator of the radial speed of a moving object delay, and first and second output -, respectively, and outputs a key block threshold.

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