SU1659973A1 - Pulse duration and time position meter - Google Patents

Abstract

The invention can be used to measure the duration of a pulse with an inaccurately known temporal position in the composition of radio communications and radar equipment. The aim of the invention is to improve the accuracy of measuring the pulse duration at an inaccurately known temporal position and the effects of broadband interference. The goal is achieved by the addition of quadrs 5, 14, and 29, a block of 16 ratios, elements 17, 20, 26, 31 delays, an integrator 25, a block of 30 ratios, an integrator 37, an adder 40. In addition, the meter contains integrator 1, 11, 13, delay element 2, 8, 23 and 36, element 11 NOT 3, 10, 27, 38, adder 4. 28 and 42, index 6, 33 of the extremum, driver 7 of the control pulse, multiplier 9 , controlled keys 12, 18, 24, 34, generator 15 linearly varying voltage, pointer 19 of extremum, counter 21 of time, attenuator 22, controlled oscillator 35 of control pulses, counter 41 times. 7 ill., 1 tab. (Ls

Description

The invention relates to a pulse technique and can be used to measure the pulse duration with an inaccurately known temporal position as part of radio communications equipment, radar, automatic monitoring and control.

The aim of the invention is to improve the accuracy of measuring the pulse duration at an inaccurately known temporal position and the effects of broadband interference.

FIG. 1 shows a structural diagram of a meter measuring the duration and temporal position of a pulse; in fig. 2-6 are time diagrams showing the type of transformations that the measured pulse undergoes during the passage of the meter blocks, they also reflect the auxiliary signals generated by the corresponding meter blocks.

These diagrams are given in the case of the absence of broadband interference, which is suppressed in the meter due to time averaging in the integrators and switching off the corresponding meter blocks by the control keys for the time when the signals generated by the measured pulse cannot be present at the inputs of these blocks, but only signals caused by broadband noise.

FIG. Figure 7 shows the graphs of dd gains in accuracy and measurements of the time parameters of the pulse.

Measuring the duration and temporal position of the pulse (Fig. 1) contains integrator 1, delay element 2, element NOT

ABOUT

ate about oh xi

CJ

3, adder 4, quadrant 5. extremum pointer 6, control pulse generator 7, delay element 8, multiplier 9, NOT element 10, adder 11, control switch 12, integrator 13, quad 14, generator 15 linearly varying voltage (CLAY), relationship block 16, delay element 17, control key 18, extremum pointer 19, delay element 20, time counter 21, attenuator 22, delay element 23, control key 24, integrator 25, delay element 26, the element 27, the adder 28, quadrtor 29, the block 30 relations, the element 31 delay, controlled key 32, an extremum pointer 33, a control key 34, a control pulse generator 35, a delay element 36, an integrator 37, a HE 38 element, a delay element 39, an adder 40, a time counter 41, an adder 42.

The input bus is connected to the input of the control key 34, the output of which is connected to the input of the delay element 23 and the input of the integrator 1, the output of which is connected to the first input of the adder 4 and the input of the delay element 2, the output of which through the element 3 is connected to the second input of the adder 4, the output of which through series-connected quadrat 5, the extremum pointer 6 is connected to the input of the control pulse generator 7, the output of which is connected to the first inputs of the multiplier 9, the adder 11 and through the delay element 8 to the second input multiply An interface 9, the output of which is connected to the control input of the control key 12, the input of CLAY 15, the input of the delay element 17, and through the NOT 10 element - with the second input of the adder 11, the output of which is connected to the input of the delay element 31, the input of the integrator 37 and the input control key 24, the input of which is connected to the output of the delay element 23 and the input of the control key 12, the output of which is connected through the serially connected integrator 13. Quad 14 is connected to the first input of the ratio block 16, the second input of which is connected to the output of GLINE 15. output The lock 16 is connected to the input of the controlled key 18, the control input of which is connected to the output of the delay element 17, the output of the controlled key 18 through the serially connected extremum pointer 19 the delay element 20 is connected to the input of the time counter 21, the start input of which is connected to the input of the counter 41 and the output of the extremum pointer 33, the input of which is connected to the output of the controlled key 32, the control input of which is connected to the output of the delay element 31, the output

controlled key 24 is connected to the input of the integrator 25, the output of which is connected to the first input of the adder 28 and the input of the delay element 26, the output of which through the element HE 27 is connected to the second input of the adder 28, the output of which through the quad 29 is connected to the first input of the relationship block 30, the output of which is connected to the input of the control key 32.

The output of the integrator 37 is connected to the first input of the adder 40 and through series-connected element NOT 38, the delay element 39 to the second input of the adder 40, the output of which is connected to the second input of the relationship block 30, the output of the counter 21 is connected to the first output bus of the meter and through the attenuator 22 - with the first input of the adder 42, the second input of which is connected to the output of the counter 41, the start input of which is connected through the delay element 36, to the control input of the switch 34 and the first output of the generator 35 of control pulses, the second output of which Inonii integrators with reset inputs 1,13, 25,37, extremum pointers 6, 19,33, 21 meters, 41 times, the output of the adder 42 is a second output bus meter.

The meter works as follows.

In the initial state of the meter, the controlled keys 12, 18, 24, 32, 34 are closed, for integrators 1,13,25,37, pointers 6,19, 33 extremums, counters 21, 41, at the output of the generator 35 control pulses the signals are zero.

Input signal: x (t) S (t. AI.GI) + n (t) (1)

consists of measured pulse:

S (U, g) / a, A - g / 2: Ј t A + t / 2,

(From Ar / 2; t A + r / 2: (2) and broadband noise n (t). Here t is the pulse duration unknown, takes values from the interval Tmin, T Max, AL is the unknown temporal position of the measured pulse, takes values in the range from Tmin / 2 to Tmax / 2 + A. The value of which is A. (Tmax - TMN) / 2, and - the amplitude of the pulse is unknown.The formula for Au and Ti denotes true values, respectively, of the arrival time and the duration of the measured pulse .

The operation of the meter starts from the moment of starting the generator 35 of control pulses. This generator sets the entire measurement cycle in the device due to the formation of control pulses at certain first and second outputs

parameters. The pulses at the first and second outputs of the generator 35 are shown in FIG. 2 and 3 respectively.

The position in time and duration of the control pulse at the first output of the generator 35 (Fig. 2a) is chosen so that for all possible occurrences and durations of the measured pulse, the latter would be located within the duration of the control pulse. Therefore, at the selected time scale, the control pulse at the first output of generator 35 begins at time t 0 and ends at time A + T max. The control pulse from the first output of the generator 35 is fed to the control input of the key 34 and opens it for the time A + T max. The input signal x (t) through the switch 34 is fed to the part of the circuit consisting of blocks 1-6 that perform a rough (approximately with an accuracy of the pulse duration) fixation of the temporal position of the measured pulse. This part of the scheme works as follows. The input signal x (t) coming from the output of the key 34 (Fig. 2c) is integrated by the integrator 1 (Fig. 2d), after which it is fed to the inputs of the delay element 2 and the adder 4. In the adder 4, the signal from the output of the integrator 1 (Fig. 2 d) stack with the same signal but delayed delay element 2

jj

(Fig. 2d) at the time t ZTMin / 2 and the inverted element is NOT 3 (Fig. 2 e). From the output of the adder 4, the signal (Fig. 2 g) is fed to the input of the quad 5, at the output of which we have a signal (Fig, 3 a) of the form:

xЈt) Ki x (t). - (3)

From the output of the quad 5, this signal is fed to the input of the extremum indicator 6, which fixes the position of the maximum maximum of the input signal. As can be seen from FIG. 3a, the signal at the input of the extremum indicator 6 due to the difference in the duration of the measured pulse gy from the delay time

t - STmin / 2 in the element 2 delay in the absence of additive noise has a flat

vertex of duration t. If there is even a small level of additive noise at the device input, the signal at the input of the extremum indicator 6 will have a maximum at an arbitrary point on the flat top, shown in FIG. 9 conditional signal. Here the dotted line shows the possible implementation of interference. As a result, the extremum indicator 6 will fix the position of the largest maximum at the point of the flat top defined by the implementation of the random noise. Due to this, the temporal position of the measured pulse is fixed by the extremum indicator 6 only up to a value of the order of the difference I Gu – t I between the true value of the measured duration and the delay value r in the delay element 2.

So, at the moment f of reaching the signal value (3) of the highest value, pointer 6 generates a pulse (Fig. 3 b), which is used to control the passage of signals in the other two measuring channels of the circuit. In particular, a pulse from the output of the pointer 6 with its leading edge triggers the driver of the control pulse 7, which generates a pulse (FIG. 3c) with a duration of 2Tmax - 3Tmin / 2. This pulse from the output of the driver 7

0 arrives at the inputs of delay element -8 (delay time Tmax - ZTMin / 4), multiplier 9 and adder 11. As a result of multiplying the signal from multiplier 9 from generator 7 output (Fig. 3c) and its delay in copy copy element 8 (Fig. 3 d) we have at the output of the multiplier 9 a pulse (Fig. A), starting at the moment t + T max - 3Tmin / 4 and ending at the instant of time the cuff - 3T / 2, Element 8 delay has a delay time T max - 3TM / four. The pulse from the output of the multiplier 9 (Fig. A) is inverted on the element HE 10 (Fig. 3 e) and is folded in the adder 11 with the output signal of the driver 7 (Fig. 3 c).

5 As a result, at the output of the adder 11

we have an impulse (fig. 3 g), starting at time r and ending at time t + T max ZTmin / 4. The pulses thus formed, shown in FIG. 3

0 E and g, come respectively to the second and third measuring channels of the device. Blocks 7-11 together with the keys 12 and 24 form a switch alternately connecting the second and third measuring channels

5 to the output of the delay element 23 (the delay time is equal to T max). The moment of switching channels t + Tmax ZTMin / 4 is chosen in such a way that it is always located within the duration of the delayed element

0 23 delays of the measured pulse. Therefore, the leading edge of the pulse at the output of the multiplier 9 (Fig. 3 d) is always within the duration of the delay of the measured pulse delayed in element 23

5 (Fig. 3 h). The impulse from the output of the multiplier 9 (Fig. 3 e) goes to the control input of the key 12 and opens it for a time from the time r + Tmax - ZTMin / 4 to the time r + 2TMax - ZTmin / 2 and in addition, with its leading edge, it starts the generator linear

variable voltage (CLAY) 15. During the time Tmax - ZTmin / 4, when key 12 is open, the input signal x (t), delayed by time Tmax in delay element 23 (Fig. 3 h), flows through key 12 ( Fig. 3 d) to the input of the integrator 13. From the output of the integrator 13, the signal (Fig. 4 a) is fed to the input of the quad 14 (Fig. 4 b), and from the output of the quad - to the input of the ratio block 16. A linearly varying voltage is applied to the other input of the relationship block 16 from the output of CLAY 15 (Fig. 4c). As a result, at the output of the block of 16 relations, we have a signal (Fig. 4 g):

"M-L + Tm" ss-ZTmin / 4 (t1-TMHH) dtV (t- - Tmax + ZTmin / 2) (4)

T Tmax ZTmin / 4

As can be seen from the above-mentioned diagrams, the signal at the output of the ratio block 16 in the absence of additive noise always has a maximum at the time of the trailing edge of the measured impulse delayed by time T max. This result follows from formula (4), if only in the last one, instead of a mixture of signal and noise x (t), substitute the measured pulse (2). The signal (4) (Fig. 4 g) through the control key 18 is fed to the input of the extremum pointer 19. The key 18 is opened for the time Tmax - ZTmin / 4 with a pulse from the output of the multiplier 9 (Fig. 3 d), delayed in the delay element 17 by TMin / 4 time (Fig. 4 d). Thus, the input of the extremum indicator 19 appears to be disconnected from the output of the relationship block 16

for time FROM g + Tmax-Ztmin / 4 DOT + Tmax-Tmin / 2. This is the start time of signal generation (4). Such a shutdown of the input of the extremum indicator 19 prevents its false alarms possible due to signal spikes (4) in the specified time interval due to the presence of additive broadband interference at the input of the meter.

Thus, a signal arrives at the input of the pointer 19 from the output of the switch 18 (Fig. 4e) in the absence of noise, which has a maximum at the time of the falling edge of the delayed pulse at the time T max. As a result, pointer 19 generates a pulse (Fig. 4 g), the leading edge of which corresponds to the position of the absolute maximum of the signal (Fig. 4 e) at the pointer input and therefore the position of the falling front of the delayed pulse at time T max of the measured pulse, i.e. pointer 19 fixes the moment of the trailing edge of the measured pulse.

Fixing the leading edge of the measured pulse is carried out by the third measuring channel of the proposed device as follows. The signal from the output of the adder 11 is fed to the control input of the key 24 and opens it

for the time from t to t + Tmax - Ztmin / 4. At this time, through the switch 24 from the output of the delay element 23 (delay time T max) the input signal x (t), delayed by time T max (FIG. 5 a), is fed to the input of the integrator 25.

The signal from the output of the integrator 25 (Fig. 5 b) in the adder 28 is added to its copy delayed by the delay element 26 (Fig. 5 c) for the time T max - 3Tmin / 4 and the inverted element NOT 27 (Fig. 5 g). Signal

from the output of the adder 28 (Fig. 5 d) comes

to the input of the square 29, from the output of which

(Fig. 5 e) - to the input of the block 30 relations. On

another input of the relationship block comes

signal of special shape, formed by blocks 37-40. To form this signal, a pulse from the output of the adder 11 is integrated in the integrator 37. The signal from the output of the integrator 37 (Fig. 5 g) is folded in the adder 40 with its copy, inverted by the HE element 38 (Fig. 5 h) and delayed by the delay element 39 (Fig 6 a) for time Tmax - ZTmin / 4. Consequently, from the output of the adder 40 to the input of the block of relations 30, an impulse arrives (Fig. 6 b) of a special form. As a result, at the output of the block of relations 30, we have a signal (Fig. 6c), which in the time interval from t + Tmax

ST

TO T + 2tmax ht „

lMV i max

5 refers to the formula

X3 (t) K3 / max -3 Cmin / 4 w J J I + Tmax - 3 Cmin / 4

TMaKc) dt / (2Tmax - ZTmin / 2 - t).

opix (t - (5)

This signal, in the absence of noise, always has a maximum at the leading edge point of a delayed 2Tmax - 3Tmin / 4 measured pulse, as can be seen from FIGS. 25-35, and also follows from formula (5), if the latter is substituted instead of a mixture of a pulse and noise x (t) is the measured pulse itself (2). The signal (5) of FIG. 6) it enters the input of the extremum indicator 33 via the control key 32. This key serves to disable the input of the pointer 33 for the time during which the rising edge moment delayed by the time 2Tmax - 3TMin / 4 of the measured pulse is not expected. Indeed, the key 32 is opened by a signal from the output of the adder 11, delayed by the delay element 31 (FIG. 6 g) for the time Tmax - Tmin. Therefore, the key 32 is open for a period of time. From ъ + Tmax - Tmin to t 2Tmax - 7TMsn / 4. At the same time, the maximum signal at the output of the block of 30 ratios (FIG. 6),

corresponding to the leading edge of the delayed 2Tmax - ZTmik / 4 measured pulse, can be located within the key transmittance window 32. Such a time limit at the input of the pointer 33 reduces the effect of additive noise on the accuracy of fixing the leading edge of the pulse of the pointer 33. As a result, the signal from the output of the key 32 (Fig. 6 d) is fed to the input of the extremum pointer 33, which fixes the position of the maximum maximum of the input signal (Fig. 6 d), which coincides with the position of the leading edge of the delayed m 2TMaks ZTMin / 4 the measured pulse. The signal from the output of the pointer 33 (FIG. 6 e) with its leading edge starts the time counter 21 and stops the time counter 41. In turn, the counter 41 was triggered by the leading edge of the signal (Fig. 2a) from the first output of the generator of control pulses 35 through the delay element 36 (Fig. 6h) for the time 2Tmax - 3TMin / 4 after the device began operating. Thus, the counter 41 records the time from the time 2Tmax ZTMin / 4 until the appearance of the leading edge of the delayed pulse for the time 2Tmax ZTmin / 4. As a result, the time recorded by the counter 41 is equal to the measured value of the time elapsed from the moment the meter starts up until the front of the measured pulse appears at its input.

On the other hand, in the second measuring channel, pointer 19 records the moment corresponding to the falling edge of the measured pulse delayed by time Tmax. This moment corresponds to the position of the leading edge of the signal at the output of pointer 19 (Fig. 4). This signal, delayed by delay element 20 at time T max - 3Tmin / 4 (fig. 6 g), stops counting time in time counter 21. Therefore, in time counter 21 time counting stops at the time corresponding to the falling edge of the delayed time 2Tmax - ZTMin / 4 meter e-pulse. In turn, this counter 1 was triggered by a signal from pointer 33 at the moment of time corresponding to the transfer of the 2Tmax – 3Tmin / 4 delay of the delayed pulse to the same time. As a result, the time counter 21 records the time of the moment of the moment corresponding to the leading edge until the moment corresponding to the falling edge delayed by the rem 2Tmax-3Tmin / 4 measured pulse. Thus, the counter 21 records the measured value of the duration of the measured pulse. This measured value of the duration from the output of the counter 21 is fed to the output of the duration of the device, and to the input of the attenuator 22 with a transfer ratio of 1/2. From the output of the attenuator 5 22, the halved measured value of the duration in the adder 42 is added to the measured value of the arrival time of the leading edge of the measured pulse, which is fed to another input

0 adder 42 from the output of the time counter 41. As a result, at the output of adder 42, we have the measured value of the arrival time 2 pulses, counted from the middle of the pulse.

5 Note that from the theory of optimal

noise immunity follows that, all other things being equal, the estimated arrival time in the proposed device in the middle of the pulse with an unknown duration is the least error compared to the estimate at other pulse points (for example, the leading or trailing edge). In addition, there is a minimal correlation coefficient between

5 errors of measuring the time of arrival and the pulse duration. However, by changing the attenuation coefficient of the attenuator 22 from zero to one, it is possible in the proposed device to obtain estimates of the arrival time, measured at different points of the pulse. In particular, with an attenuator gain of 22 equal to zero, the device will measure the arrival time on the leading edge.

5 impulses, and with a transfer ratio equal to one, on the falling edge.

The measurement cycle in the device ends with the generation of control pulses 35 by the generator at its second output of a short control pulse {Fig. 2 b), delayed relative to the trailing edge of the pulse at the first output of the block (Fig. 2 a) at the time of TInd. The time TInd is chosen to be minimal, but sufficient to record (read) the measurement results. In particular, if the time required for registration of results is Tr, then Tind. Tr + 2Tmax, where: time 2Tmax is assigned to complete the measurement process,

0 delayed by time 2Tmax - ZTmin / 4 measured pulse. Thus, until the pulse appears at the second output of the generator 35, the measurement is completely finished. This impulse comes on

5, the reset buses of the counters 21 and 41, the integrators 1, 13, 25, 37, CLAY 15 and the extremum indicators 6.19, 33, and thus bring the circuit to the initial state.

As a result, the meter is ready for operation.

It should be noted that the values of measurement errors in the device are not affected by the values of the coefficients Кч, 2, Кз, which determine the transfer coefficients of the circuit blocks. These coefficients are selected depending on the operating conditions of the meter in such a way as to match the dynamic ranges of the signals and typical units used.

Let us consider the gains dt - Vnr / Vzr- in the accuracy of measuring the duration and d & V (L / Y% is in the accuracy of measuring the temporal position, where is the scattering (mean squares of errors), respectively, of the arrival time and duration in the proposed device, and V pA and V are the corresponding scatterings in the known device. These winnings are determined by the relations

13 + 133 ei + 15eЈ-е |

5A

13 (1-Ј§У

3-f69 E | -MbEa

eg

13 (1-ef) 4 is valid when lЈa I 1, where Јe (z-a0) / a0 is the detuning of the amplitude a0 of the measured and a and the expected pulses (the value of a and the amplitude of the expected pulse determines the value of the coefficient Kz). Dependencies of dibg wins exactly

measurements of the temporal parameters of the pulse from the detuning value are shown in FIG. 7, where 3d is a continuous line; dt dashed line.

For individual values of the win win rate parameter (id), see the table below:

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION Pulse duration and temporal position meter containing two integrators, input bus, two output buses, three extremum pointers, two time counters, five controllable keys, four delay elements, four HE elements, four adders, an attenuator, a driver a pulse, a multiplier, a generator of linearly varying voltages, a generator of control pulses, the output of which is connected to the input of the fourth delay element and the input of the control P nor the first control key, the input of which is connected to the input bus of the meter, the output of the first control key is connected to the input of the third delay element and the input of the first integrator, the output of which is connected to the first input of the first adder and through the series-connected first delay element and the first HE element with the second entrance 0 of the first adder, the output of the first extremum indicator is connected to the input of the control pulse generator, the output of which is connected to the first inputs of the multiplier, the second adder and through the second delay element to the second input of the multiplier, the output of which is through the second element is NOT connected to the second input of the second adder whose output is connected to the control input of the second controlled 0 key, the output of the third delay element is connected to the input of the third control key, the control input of which is connected to the generator input of a linearly varying voltage, the output of the third control key 5 is connected to the input of the second integrator, the output of the fourth control key at the extremum, the output of the first time counter is connected to the first output bus of the meter and through an attenuator 4- to the first input of the fourth adder, the second input of which is connected to the output of the second time counter, turn coupled to an input start time of the first counter 5 and the output of the third extremum indicator, the start input of the second counter is connected to the output of the fourth delay element, the output of the third element is NOT connected to the first input of the third adder, the second 0, the output of the control pulse generator is connected to the reset inputs of the first, second integrators, first, second, third extremum indicators, first, second time counters, the output of the fourth sum 5 of the matrix is the second output bus of the meter, characterized in that, in order to improve the measurement accuracy pulse duration at an inaccurately known temporal position and exposure to a wideband interference; two integrators, three quadrators, two relationship blocks, five delay elements, a fifth adder, an output to torogo coupled to a second input of the second block 5 relations, the first input of which is connected via the third quadrant to the output of the third adder, the second input of which is connected to the output of the third integrator and through the sixth delay element to the input of the third element NOT; the input of the third integrator is connected to the output of the second controlled key, the input of which is connected to the input of the third controllable key, the control input of which is connected to the output of the multiplier and, through a third delay element, to the control input of the fourth controllable key, the input of which is connected to the output of the first control unit relations, the first input of which through the second quadrant is connected to the output of the second integrator, the output of the generator of linearly varying voltage is connected to the second input of the first relationship block, the output of the second extremum indicator is connected to the input of the first time counter via the fourth delay element, the output of the second adder is connected to the input of the fourth integrator and 0 five through the seventh delay element - to the control input of the fifth controllable key, the input of which is connected to the output of the second relationship block, the output of the fifth controllable key is connected to the input of the third extremum indicator, the output of the fourth integrator is connected to the first input of the fifth totalizer the fourth element is NOT the ninth delay element connected to the second input of the fifth adder, the output of the first adder through the first quad is connected to the input of the first extremum indicator, the second generator output y The control pulses are connected to the reset inputs of the third and fourth integrators. FIG. R l + t max AI 0 Ti-t  max  t-CTmc.x-iT -4t „ t TMM-3 .czzn t J ъс -ie t .IZL 0wi3 t z. L t -t t / z well ABOUT L / about I AG K-t F «b A, TTW so and- w thirty 20 ten V - / -0.45 00.55 7 7