SU928371A1 - Analogue integrating computer - Google Patents

Description

(54) ANALOG INTEGRATING COMPUTER

one

The invention relates to computing technology and automation systems and can be used in converters of integral parameters of a signal and spectrum analyzers.

A low-pass filter is known, which contains signal and final integrators and keys, which, depending on the choice of the key program, implements low-pass filtering with piecewise nominal windows, or Dirichlet weighting functions (rectangular window), Bartlett (triangular window), parabolic and other 1.

Also known is an analog integrating calculator that contains integrating amplifiers and switches that implements the Blackman weighting function 2.

The disadvantages of the known devices are that they implement non-optimal weight functions that lose to the optimal Papoulis window.

. Closest to the proposed calculator is a calculator containing

hence the connected signal integrating amplifiers connected via the first key to the first input of the calc. a running integrated amplifier, the second input of which through the first scale & ny block and the second key is connected to the input of the calculator connected via the second scale block to the first input of the first signal integrating amplifier, as well as inverting

10 amplifier, whose input through the third scale unit is connected to the output of the second signal integrating amplifier, and output x: is connected with the second input of the first integrating amplifier GZ.

15 The disadvantage of this calculator is the low accuracy of operation under the condition of the low-frequency interference concentrated on the spectrum.

20

The purpose of the invention is to improve the accuracy of integration under the action of low-frequency interference concentrated on the spectrum. This goal is achieved by having an analog integrating calculator containing the first and second integrators and the first key connected in series, the output of the second integrator being connected to the inverting input of the first integrator and through the first key with a non-inverting input of the third integrator, the non-inverting input of the first integrator 5 is input of the analog integrating calculator, contains, the swarm key and the fourth integrator connected to the output of the third integrator, the first inverting input of which is connected to the output of the fourth integrator, is provided by the output of the analog integrating calculator, the second inverting input of the third integrator is connected via the second switch to the output of the second integrator integrating calculator. The transmitter contains the first Integrator 1, the second integrator 2, the third integrator 3, the fourth integrator 4, the first key 5, the second key 6. The integrators 1 and 2 are connected in series, the output of the integrator 2 is connected to the input of the integrator 1 and through the key 5 to the first integrator input 3, and via switch 6, to the second input of the integrator 3. The output of the integrator 3 is connected to the input of the integrator 4, the output of which is connected to the third input of the integrator 3 and is the output of the device. The proposed analog integrating calculator implements the Papulis window (Wptt) r. WJi) | - s-inctt-aico5cit nPHOitiit OD, l. c | g. ,, -., 1 11) sitial4Ji-at) cosqt npM i., Where in what q is the transfer coefficient of any integrator over any input. The work of the calculator in two intervals will be considered separately. . During the first interval | o, the key 6 is closed, the key 5 is open. In the second interval, key 5 is closed, key 6 is open. Under zero initial conditions, the expression for the transfer function of two series-connected integrators 1 and 2 or 3 and 4 with feedback (rings), as for a linear system, is HCs) where d is the one-sided Laplace transform operator. 1. Interval About; | -. The transfer function is defined as the product of the transfer functions of the two rings from the integrators 1-2 and 3-4 with the key closed 6, (s) (. I) The pulse transition function b (t))}; - | - (Sindt-oitc05clt; the output value for the fourth according to the scheme (Fig. 1) of the integrator at the end of the interval t 2 (t) .j (t -) () a-sr ii (() co5au.aCL) di; o Additionally, we find the output value for the first integrator on end of interval. It will be necessary to take into account non-zero initial conditions in the second interval. The expression for the transfer function of the ring section before the output of the first integrator Through the transfer functions of the ring and the second integrator 0 t3S) rH (S) / H (.S) The corresponding IFR is (fc): qcosott Now we finally get dCoec (-tt) (C) c «ooedC- (Cldt о. 2). interval -o- - carry out research by superposition result part 1 sozdaots nonzero initial conditions excluding the input part 2 is generated a signal with zero initial conditions H and L 1. Consider that intervala- -1- length equal to half the period.. free vibrations of each of the rings. The initial condition 2 J / d on the fourth integrator causes a cosine-shaped process at the output and after half a period

there will be a change of sign with the same module, i.e.

I d

OJi - 1L - Itsincir4 (jr.ait) cosair t) dT (g) a o

The initial condition on the third integrator causes a sinusoidal process at the output and its contribution, measured after a half-period, will be zero.

A nonzero initial condition A on the second integrator leads to the appearance of a cosine-like process at the input of the second ring. The impulse transient function (IAP) of this ring is a sinusoidal function of time with the same period. Convolution of these two functions on an interval equal to half the period; gives zero result:

cha a

al

d

 o15ll (i-irJA eos sin aqtdi: o

l o

ZG

five

r

The initial condition Z at the output of the first integrator causes a sinusoidal process at the input of the second ring

kind of

Vj / -indt

Clotting it with a sinusoidal IAP ring makes a contribution

1L

q.

 jT / aS -a-sin (t-) dc- | v-,

T.

Here, the first factor under the integral sign represents the transition process from the non-zero initial condition of the first integrator, and the second factor is the IAP of the second ring.

Using Vl / d, we write the expanded ratio -

V / d-S -)

about.

The total of part 1 is written as a sum (2 and (3)

l d

.Tt ((r-qrcoSciC) (C) dr

ri J

This formula is the result of processing the signal in the first interval with a weight

Gs1

- (cosa-fc) AT o ..

“I (t).

W

otherwise Oh

Free oscillations in the second interval took part in the formation of this result.

Part 2. After taking into account all the components resulting from the signal (t) in the first interval, we determine the result of signal processing a (t) in the second interval Γ. Since the processing starts at time t, we must subtract g from the IFF argument

j 5 a t-C-) -d (i-c4Hax

-I

()) 5 (Ji-qC) cx) St

3i d

X: (t) am

thirty

The result is obtained as if the signal were processed with a weight

  c (i + (ji-cit) co5dt PRI, 4l.-t). (5)

  iisheo

Comparison of (4) and (5) with (1) allows us to conclude that the structure implements the WF Papoulis with an accuracy of a constant factor.

The advantages of the Papulis window are known: its spectrum has a minimum central second moment. Compared with the Hamming window implemented in a well-known calculator, the Papoulis window suppresses interference in the near part of the opacity zone 3 dB more, and the side lobe decay rate is 24 dB / octave versus 6 dB / octave.

Claims (3)

The effect of the application of the proposed calculator is to increase the accuracy when operating in the conditions of interference. Such interference, in particular, is always present as a variable component at the output of the detectors. The use of the fourth integrator, which together with the third integrator forms a ring, is analogous to the ring from the first and second integrators, allows Papulis to implement the optimal weight function and reduce the effect of interference. Claims of the invention An analog integrator voltage circuit comprising a first and a second integrator connected in series with the output of the second integrator connected to the inverting input of the first integrator and through the first key to the non-inverting input of the third integrator, the non-inverting input of the first integrator is the analog input. integrating calculator, which is related to the fact that, in order to improve the accuracy of integration 18 under the action of low-frequency noise concentrated on the spectrum, it contains the second call and the fourth integrator connected to the output of the third integrator, the first inverting input of which is connected by the d output of the fourth integrator , Which is the output of the analog integrating computer, the second inverting input of the third integrator is connected via a second switch to the output of the second integrator. Sources of information taken into account during the examination 1. USSR author's certificate No. 481910, cl. 5 06Q 7/18, 1975. 2. USSR author's certificate NO 7236OO, cl. QO6Q 7/18, 1979. 3. USSR author's certificate number 633036, cl. G06G 7/18, 1977 (prototype).