SU1004957A1 - Pulse burst time position determination device - Google Patents

Description

(yCTPOiJCTBO FOR DETERMINATION OF THE TEMPORAL POSITION OF A PULSE OF PULSES

. -. - -one

The invention relates to radar technology and can be used in the implementation of automatic tracking systems that operate on information encoded in the temporary position of a bundle of video pulses relative to the middle of the observation interval.

A device for estimating the temporal position of a burst of pulses is known, which is based on temporal discrimination, which allows determining only the position of the center of mass, and not the center of the burst, which has stochastic (random) parameters (number, duration, amplitude and pulse interval in the burst) relative to the middle (joint gates) observation interval

T „tc + AtTj. where 1 AT ,. - duration stroy: Soa 1.

The randomness of the parameters of the laundress leads to destabilization of the steepness of the disk -

riminators and, consequently, to large variances of measurement errors and low reliability of the automatic mode of the systems.

Closest to the proposed invention is a device for determining the temporal position of a burst, containing a threshold level generator, a sensor of observation intervals, a comparator, a reference voltage switch And an integrator, which allows the temporary fixation to determine the center position of one pulse relative to the middle of the observation interval 2.

However, this device does not allow one to estimate the temporal position of the burst of video pulses.

The purpose of the invention is to expand the functionality of the device ..

The goal is achieved by the fact that the device containing the source of video pulses, the output of which 31 is connected to the first input of the comparator, and through the threshold level generator to the second input of the comparator, the output of which is connected to the first input of the voltage switch, the second input of which is connected to the output of the observation interval generator, and the output - to the integrator input, are additionally introduced a pulse shaper, an OR element, an integrator, a switch, a difference determining unit and a fixation unit The voltage level is equal, the second output of the voltage switchboard is connected to the control input of the switch, whose input is connected to the integrator's output, and the output is connected to the first input of the difference determining unit, the output of which is connected to the input of the voltage level fixing unit the reference voltages are connected directly to the input of the additional integrator and, through a pulse shaper, to the first input of the OR element, the second input of which is connected to the fourth output of the reference voltage switchboard and the pack The inputs of the integrator and the voltage level fixing unit, the output of the element OR are connected to the control input of an additional integrator, the output of which is connected to the second input of the difference determining unit, in addition, the switch of the reference voltages contains two elements And NOT, two RS flip-flops, an amplitude detector, two differentiation units / and a difference determining unit, the first input of the reference voltage switch is connected to the first j input of the first And element, the output of which is connected in series The first differentiation unit and the amplitude detector are connected to the first input of the difference determining unit; the second input of the reference voltage switch is connected to the second input of the first element I directly and through the second differentiation unit to the fourth input of the reference voltage switch, C-inputs of the RS-flip-flops and the second input the difference determining unit, the output of which is connected through the first element NOT to the R-BXO of the first RS flip-flop and directly to its S-input and the first input of the second element I, whose output is n combined with R- and S-BXOdami second RS-flip-flop inverse Q

(Including at the outputs of the nodes: the output of which is the third output of the switch, the first output of which is the inverse output of the first RS flip-flop, the direct input of which is connected to the second output of the reference voltage switch directly and through the second element NOT to the second input of the second element I. The block diagram of the device is shown in Fig. 1. The device contains a source of 1 video pulses, a shaper 2 of a threshold level, a comparator 3 a shaper of 4 observation intervals, a switch 5 of reference voltage, a form + pulse 6 o, element 7 OR integrators 8 and 9, switch 10, difference determining unit 11, voltage level fixing unit 12. In Fig. 2 is a block diagram of reference voltage switch 5, holding element I, differentiation unit 5-2, 53 amplitude detector, differentiation unit, difference detection unit, element NO, RS trigger, element NO, element 5-9, and RS trigger, 5-10. In Fig. 3-5, the voltage plots acting on the output of the device nodes determining the temporal position of a burst of pulses at different mutual temporal positions of the burst. video pulse in (for the space taken And 2, the duration of the pulses is different) and the interval of observation. FIG. 3 shows the voltage plots at the outputs of the device nodes when the pack boundaries — the leading front t T of the first impulse of the pack and the falling front t 1 of the last impulse of the pack are within the observation interval TC t, —tf ,. FIG. - voltage plots at the outputs of the device nodes, when the left boundary of the pack — the leading front of the first pulse of the pack — is to the left of the beginning of the observation interval, T.e.t-1c. . FIG. 5 shows the voltage plots at the outputs of the nodes of the device when the right boundary of the packet is the trailing edge of the last pulse of the packet to the right of the end of t. observation interval. T.e.lTaw t. FIG. The following notation is used for stress diagrams, actual - source 1 for all pulses C (t); b - comparator 3 LU (t) j; C — Former i observation intervals LU4 (t); g - element 5-1 AND, U. (t); d - amplitude detector (t); e is a differentiation unit lLU5-4 (f) j; - the determination unit 55 is different. (t); 3 — at the first output, the switch of the voltages 1) 54 (t) and — at the second output of the commutator, 5 reference voltages. Mt); k - at the third output of the switch 5 reference voltages); l - integrator 9 lUgCt) ;. m - switch 10); n - integrator 8 LUgCt); o - spacing determination unit 11 and (t). FIG. 6 shows the principle of estimating the time position of a pack by temporarily fixing it on the front and rear ends of the pack. The voltage shaping algorithm of the signal U {Z, t) corresponds to the expression (V-i l Ht) - i () dt - J b (t-) - i (t-T) dtJ, where K is the integrator conversion factor. 7 tH-tK Taryi Discrepancy 2 FIG. 7 - Static characteristics of the device. The parameters of the characteristic are its steepness, .. 1 / K AND A HiW 2 where A is the amplitude of the burst pulses at the first output of the switch 5 and perm m, 2-1, A) (T,) v "axВ the principle of operation of the device for determining the temporal position of the np pulses relative to the middle of the observation interval, the temporal fixation of a single pulse on both fronts is laid. “The device works as follows. Suppose that the leading front i of the first and the falling front t t of the last burst of the stack is within the observation interval T c, i.e. 1G. t .. and ,,,. where is the temporary position of the beginning and end of the interval of observation TC (Fig. 3). The output voltage U (t) of the source 1 of the video pulses (Fig. Over) is fed to the input of the Comparato 3, where it is compared with the threshold voltage U (t) received at the output of the Former 2, shown on the other input of the comparator 3 From the output of the comparator 3, the voltage 1) 3 (1) (Fig. 36) is fed to the first input of the switch 5 of the reference voltage: the second input of which receives voltage pulses U4. (T) (Fig. Sound) taken from shaper output k intervals of observation. .. With the start of observation, if a signal is not detected. From the first output of the switch 5, the positive is removed by (,) A (Fig. 3), the UK amplitude of which remains unchanged until the signal t 1 / is detected (Fig. 3, 3). At the time the signal is detected (the leading edge of the first pulse of the packet crosses the threshold level) (Fig. Za, Z3), the voltage u5 (17 / t;} O and remains equal to zero until the end of the observation interval J t - t. From the output of the switch 5 the voltage Ue-. (1ts tif tx) is fed to the input of the integrator 9. With a reset. As a result of the integration, a voltage is formed at the output of the integrator 9 by the end of the observation interval (Fig. 3L) .L) r and (t) dt T Aj i (i-tj,) - Kt-T ;,) dt + bj bk + O J .l (tT) - l (tt,) dt At f A (T, -CH), (1) bn whose magnitude is proportional to temporary front-first position mpulsa bundle t with respect to the observation interval Tc. The voltage U52. (T) at the second output of the switch 5 is constant and equal to zero until time point P. At t / 00 T, and (t) takes the value A (fig. Zi), which remains constant until the end tj of the observation interval This voltage goes to the control input of the switch 10, the input of which receives the voltage Ug (t) (Fig. 3L) taken from the output of the integrator 9 "At U5a (t) the switch 10 disconnects the output of the integrator 9 from the first input of block 11 determine the difference and, consequently, the voltage of the first input of the last (Fig. 3m) U- (o () O in MOMeHTt ;, U5j (t / T) A switch Torr 10 connects the output of the integrator 9 to the first input of difference determination unit 11, and thus the first input unit 11 operates voltage () U H;. Qp (t) .sftft, u «t +)« ACti-tM .-. Conditions (1), (2) and (3) are satisfied if the leading edge of the first burst of the packet is within the observation interval (Fig. 36 and Sv, Fig. 56 and SB), i.e. tj.-r, tK. If the leading edge of the first pulse of the packet is outside the limits of the observation interval (Figs. B and 4c) or coincides with them, i.e. 1k.5T i $ ty ,, then the voltages: Uj (t) and U (t), 4m are removable from the first and second outputs of the switch 5 of the reference voltages, respectively, take the values U5 () -OG. (-TGi-StH) BUT ,()

The voltage U5 (t) taken from the third output of the switch 5 of the reference voltage simultaneously enters the input of the integrator 8 with a reset and the input of the pulse former 6, which differentiates the incoming voltage and performs, for example, the detection of negative pulses from the output of the former 6, go through the emendment 7 OR, the control input of the integrator 0 on the observation interval (Fig. 3H) is reset to zero at the time of C 2, corresponding to the falling edge of the pulses. With this algorithm, the integrator 8, by the end. the observation interval 1 from the output of the integrator 8 is removed voltage (Fig. 3N)

to Ug (,.) 1 u (t) dt

Lschil -1

 BUT; Kt-T,) - i (t-t) dt

 A (, with t. (5) O, with, Vtc ... T2 (,, I A, AT 4. t. 4m k7 which remain until the end of the observation interval (Fig. 3, u). In this case, the first input of the block 11; 1 is the voltage U-fo (t) Uy (t) О Gfig iM, l), the output of the integrator 9 is connected to the first path of the block 1 1 switch 10, because U (t)., A. The voltage ((t) at the third output of the switch 5 is constant and equal to zero until the falling edge T. of the first pulse of the threshold level packet crosses (Fig. Za, Zk). The time J Ui53 (t) takes the value A (Fig. Zc) which remains constant until the end of the interval. Observations if n is the number of pulses in a bundle, is one If n 1, then (t) retains the value of A until t (the leading edge of the subsequent impulse of the pack crosses the threshold level, Fig. In.) At t / T2, on voltage and 5- t () O and keeps the dto value up to the time T., the falling edge of the second pulse of the stack (Fig. 3a) crosses the threshold level. (). From the time T U, j (t,) A remains constant until the end of the observation interval . In other words, the voltage U (t) taken from the third of its output KOMMyTatopa 5 is the reference voltage (It takes values A in the pauses V between pulses in a bundle. In n-1, nf1,2m-1, m and distinct from zero, i.e. also equal to A in the interval between the falling edge G of the last of the n pulses of the burst and the end of tx; the observation interval T, if 1r T2u „1 otherwise, i.e., when t C Cj ty, is outside the boundaries of the observation interval, fig. 56, 5c), the voltage Ug (t) O (fig. 5h), tt, as in this case the voltage U (t} O arrives at the input of the integrator 8 (fig. five ), 17 / Tz. The voltage Ug (t) over the entire observation interval goes to the second input of block 11, where it is subtracted from the voltage UQ (t) of the first integrator 9, i.e., and, () U (j (t) - Ug (t). and ,, (t $ t) - Ue (t). (6) The voltage U (t), taken from the output of block 11, by the end of the observation interval, t, takes the value following from the expressions (3) and / x ACh (+,, + gi) (7) where Cc K (, Ci2 is the coefficient of integrators 9 and 8, respectively. From FIG. 6 it follows that the temporal mismatch between the center of the pulse train and the center -H of the observation interval is the difference of their temporal positions, i.e. 7- Lee tK-tH. / QX 2 2 2, 2 In addition, from FIG. 6, it follows that half of the area difference S - A () and SA (t, - ,, jji is proportional to the time difference Z, that is, US (Z)).) (9) Comparison of expressions (7) and ( 9) taking into account the geometrical interpretation of the meaning of the integrals included in (7), allows us to conclude that, u (t) AS (Z) (10) m. The amplitude and sign of the voltage and (t t) j-0) at the end of the tj observation interval with the coefficient K are proportional to the magnitude and sign of the time error Z (Fig. 6) expression (8). The voltage (t), taken from the output of block 11, receives the input of the voltage level-fixing unit 12, the control input of which receives negative clock pulses of 10 7 voltage pulses (t}, removed from the time tt (K 0,)) the fourth output of the switch 5 of the reference voltage. In parallel, these same pulses are fed to the control input of the integrator 9, and through element 7 OR, to the control input of the integrator 8. With a reset. During the time of operation of the clock pulses at time tt (+0 instantaneous value of voltage U (t) and zero The integrators 8 and 9 are applied. The voltage U () of the voltage Z is removed from the output of the voltage level fixing unit 12, U () U (.0) U, (tt, + 0). In the case of no pulses of a pack in the observation interval or if they are not detected ,. (t) 7 U (t), the voltage U (t) O, since in this case the second input of the block 11 receives the voltage) O, and the first output of the block 11 by the switch 10 is disconnected from the output of the integrator 9, the output which by the end of the observation interval is acted upon) 1kenie U9 ((t) U, (t)) ATz, because its input is voltage, (. (t) 7 U (t) A. Voltage) at U, j ( t) U (t) equals but to zero, and therefore, switch 10, to the control input of which this voltage is applied, is open, which is adequate to the equality U (t). To form the voltage and., (Z t) mismatch, we used reference voltages Ut (t) ,,. U5, (t), and U54 (t) which are formed by the switch 5 of the reference voltage (Fig. 2). Switch 5 works as follows. The voltages U5 (t) (Fig. 36,, 56) and U4 (t) (Fig. Sv, 4c, 5c), respectively, are fed to the first and second inputs of the switch 5 of the reference voltages from these inputs receive Ui (t ) - to the input of the element U4 (t) - to another input of the element 5-1 I and to the input of the block 5 of differentiation. Element 5-1 AND, having carried out the operation of the logical multiplication of the voltages Uj (t) and. (T), forms the voltage U5 (t) U (t) vU4 (t), which is fed to the input of the differentiation unit, from the output of which life:

V4 (-ft (M))).

arrives at the input of the amplitude detector (which performs the operation of full-wave bias detection of voltage (Ug-.Ct)). The voltage is removed from the detector output (Fig. A, Fig, yd, Fig. 5e)

U, (t) | U5, i (t) | ft (U ,, (t) (- U4 {t), (11)

which is fed to the first input of block 5-5, to the second input of which voltage is applied (Fig. Ze, Fig. te, Fig. 5e)

() (12) formed by the differentiation unit from the voltage M4. (T) (fig. Sv, c, 5c), coming to its input from the second input of the switch 5 (fig. 2).

, Block 5-5 for determining the difference performs the operation of subtracting the Ug (t). (Fig. Zd, "A, 5d) from the voltage (i (t) (Fig. Ze, ё, 5e) and forms a pulse voltage (Fig. Zzh,, 5g)

V5 (;) - iv d dt

(U ,, (t) U4 (t))),

(13)

which contains information on the mutual temporal positions of the boundaries of the observation interval and the boundaries of each of the pulses of the stack, which are in the observation interval of the TC.

If the leading edge of the first burst pulse and the trailing edge of the last m-th pulse of the burst are within the observation interval / t. ...,. (I) then, in the composition of the voltage U,) (Fig. ЗЖ) there are a positive impulse t and a negative impulse t of the limits of the nab / ode interval and, in addition, the number of other negative impulses is even.

If the leading edge of the first impulse of the bundle coincides or is to the left of the 1s boundary of the observation interval (Fig. 4b, 4c), i.e. T tH (15), then the positive voltage pulse tj and the number of other positive pulses are absent in the voltage (t) with the exception of the pulse t, odd (Fig. “g).

If the trailing edge of the last t-but-j .th pulse of the bundle coincides or is 5 to the right of the boundary t j of the observation interval (Fig. 56, 5c) i.e. / tn (16); then, as part of the voltage

Ug-- (t) (Fig. 5g) contains a positive start pulse t and a negative pulse of the end t of the observation interval, the number of other negative pulses, unlike conditions (It), is odd.

If there are no signals in the observation interval, or U (t) U (t) are not detected, then U. (t) contains only a positive pulse ty, and a negative pulse t.

On the basis of these features, the operation of sources of reference voltages, in which asynchronous single-stage RS-TDiggers 5-7 and 5-10 are used, is organized.

In the initial state, i.e. up to the moment tu O of the beginning of the observation, the inverted output of the RS flip-flop 5-7 relieves the voltage (t t) O, which is fed to the first output of the switch 5 and, therefore, the voltage is 30 (Fig. W, h, 5 dl,). ) () 0. (Г7) The direct output of the RS flip-flop 5-7 is relieved of the voltage (tctn) A, which is fed to the second output 35 of the switch 5 of the reference voltage and, therefore,

and 5-2. () U, (t 1c) A. (18) The inverted output of the RS flip-flop 5-10 relieves the voltage Uc (} 40 O, which goes to the third output of the switch 5 of the reference voltage and therefore

and 5- () () 0. (19) The indicated states of the RS-triggers 4 $ and 5-10 are set by the negative clock pulses of the voltage U (t) (Fig. Ze, e, 5e), which are fed to their control inputs from the output of the block 5 differentiated neither. The same voltage simultaneously arrives at the fourth output of the switch 5 of the reference voltage and, therefore

U (t) (t) (t) .- (20)

Claims (2)

Since both RS-flip-flops 5-7 and 15-10 change their state when there are negative pulses on S or R inputs, the positive voltage pulses t) under conditions (1) and (16), acting simultaneously on S and through the item NOT on the R-inputs of the RS-flip-flop 5-7 and on the input of the And element changes the state. . only trigger 5-7. In this case, the voltage U (t7 / tn - At) U (t7 / tv,) A (Oig. 3h, 5h) (21) U, i (), (t7t) O (fig..Zi, 5i ) (22) In expressions (21) and (22), by At, the time interval required for the RS-flip-flop 5-7 to change the state is indicated. At time T, the first RS-flip-flop is returned to the first negative impulse (nx) under conditions (14) and (16). in the initial state, affecting its S output. The RS-flip-flop 5-7 does not react to the positive pulse coming from the output of element 5-6 NOT to its R-input. The voltages removed from the outputs of the RS flip-flop 5-7. Respectively, take the values of the initial state, i.e. - about U54 (t7 / C;) Ujr-T (t7 / T) .0, (f,) U () A, which do not change until the beginning of the new observation interval, as well as in the absence of tj pulses in voltage (t) (15). Positive voltage pulses (t) to the output of the element 5-9 I do not pass, and therefore the RS-three germs remain in the initial state, since the voltage l (t arriving at its inputs from the output of the element and is zero, not review of the presence of the resolving potential (t 0), which forms the element 5 8 | inverter voltage (tt - 0) A under the conditions (14) and (16), which comes from the direct output of the RS flip-flop. The first negative pulse voltage U (t -T /)), returning the RS-flip-flop 5-7 to the initial state under conditions (I) and (16) on the R and S inputs of the RS-flip-flop 5-10 again not received ate, since LT D - | -'A Th. where DT,) is the pulse duration n p; D1. - the duration of the process to change the state of the RS-trigger 5-7; - the reaction time of the element 5-8 HE 100 7 and therefore the input voltage of the element 5-E I, (t C., + 0) 0. RS-flip-flop 5-10 at t T: remains in the initial state. The second and each subsequent negative voltage pulses and (t 7Т) ,, arriving at the R and S input of the RS-flip-flop 5 10 change each time its state, since three | - 5-10 pulses operate in the counting mode , and therefore, from time Tj dot; RS-trigger generates voltage Ug-.o SSa, t) A with T4, (- b.,) O with T4.DO, i, t tU °, (t) A. In other words, voltage, (t), taken from the inverse output of the RS-flip-flop 5-10 / takes the value A in the pauses only between the pack pulses that are in the observation interval under condition (16) and on the interval T to t | (under conditions (I) and (15). v The initial state of the RS-flip-flop 5-10 is set by the pulse tx independently of the signals on its R and S inputs. Such an implementation of the switch 5 of the reference voltages allows the formation of control and reference voltages that are used during the formation The error signal voltage and control of the device operation for determining the temporal position of a burst of pulses. - Introduction to the device, new communication nodes allows obtaining a universal device for determining the temporal position of a burst (n T 1) of pulses that have both deterministic and and random parameters (number, duration, period of the pulse in the packet), relative to the middle of the observation interval. The proposed device for. determining the temporal position of a burst of pulses with the same duration of observation intervals has a linear characteristic almost throughout the aperture. In addition, the dependence of the steepness of the characteristic on the parameters of the signals is excluded, which improves the accuracy and reliability when operating in the automatic measurement mode. The linearity of the device characteristics reduces the likelihood of tracking failure with the same signal-to-noise ratio and, therefore, increases the noise immunity of such devices. 15 10 The claims 1. A device for determining the temporal position of a burst containing a source of video pulses, the output of Kotoporo is connected to the first input of the comparator directly and through the threshold level generator to the second input of the comparator, the output of which is connected to the first input of the reference voltage switch, the second input of which is connected to the output of the imaging interval generator and the output to the integrator input, characterized in that, in order to expand its functionality, Dena pulse shaper, an OR gate, an integrator. switch, difference determination unit and a voltage level fixing unit, with the second output of the voltage switching switch being connected to the control input of the switch, the input of which is connected to the integrator output, and the output to the first input of the diversity detector, the output of which is connected to the input of the voltage level fixing block, the third the output of the switch of the reference voltages is connected directly to the input of the additional integrator and through the pulse shaper to the first input of the OR element, the second input of which is connected to the fourth output of the switch of the reference x voltages and the control input of the integrator and level fixing block voltages output of OR element connected to the control input of the additional integrator whose output is connected to the second input of the difference determination unit. 2. The device according to claim 1, about tl and that the switch cutting the first element NOT to the R-input of the first RS-flip-flop and directly to its S-input and the first input of the second element I, the output of which is connected to the combined R- and S-inputs of the second RS-flip-flop, the inverse output of which is the third output of the switch , the first output of which is the inverse output of the first RS flip-flop, the direct input of which is connected to the second output of the switch of reference voltages directly and through the second element NOT to the second input of the second element I. Sources of information taken into account in the examination 1. Reference electronic systems 40, vol. 1, edited B.Kh. Krivitsky, M., Energie, 1979, p. 11, fig. 1.7. 2. USSR author's certificate number 8221 0, cl. G OA F 10 / OA, 1979. The 16 reference voltages contain two AND elements, two NO elements, two RS triggers, an amplitude detector, two differentiation units and a difference determining unit, with the first input of the reference voltage switch connected to the first input the first element And, the output of which through the series-connected first differentiation unit and amplitude detector is connected to the first input of the difference determining unit, the second input of the reference voltage switch is connected to the second input of the first element And directly and the second differentiation unit cuts to the fourth output of the reference switch, voltages, C-inputs of the RS-flip-flops and the second input of the difference determination unit, the output of which is connected via .3 FIG L