DE1588114A1 - Method and arrangement for generating an analog signal which depends on the difference between two variable digital quantities - Google Patents

Description

S.p.A.CEA-PSREGO, Milano, Via Gradisca 11 / Italy

Method and arrangement for generating an analog signal which is the difference between two variable digital Sizes depends.

The invention relates to a method and an arrangement for generating an analog signal that is derived from the difference between depends on two variable digital quantities.

Arrangements for control circuits are already known, ie the position information of the moving part with respect to the fixed deliver a stationary part of a machine in digital form, for example, read arrangements can consist of counters, that count the incremental values during movement, or from devices that measure a variable, e.g. via a Analog-to-digital converters and deliver them in digital form.

ORIGINAL INSPECTED 009850/1665

COPY

As an example, reference is made to an application in which Setpoint 7 / ert which corresponds to the position in which the movable part is to be brought, the actual value which corresponds to the position, in which the moving part is located, is subtracted algebrically and the result of the subtraction for actuation the control circuit is utilized.

In other known arrangements, only the sign of the difference is evaluated and depending on whether the distance from Target point is larger or smaller than a certain value, the control is operated in one or the other direction »

In contrast, in the case of the invention, one is given in digital form The variable is converted into an alternating voltage, the phase position of which is proportional to the value of the variable.

The object of the invention is to provide a method and an arrangement for the implementation of this method, with the help of which evaluable signals can be generated in a simple manner, e.g. for Production of automatic regulation or control circuits in digital form,

According to the invention, a method for generating an analog signal is which depends on the difference between two variable, occurring in digital form, characterized by, that pulses of higher frequency are generated, which are fed to two frequency-dividing counters, which on two lines are connected in parallel to each other and in series with a generator that emits a signal with a rectangular waveform, that two numbers are sent to these counters in an instant lying between two input pulses, which represent a phase

009850/1665

15881H

Generate shift between the two signals having a rectangular waveform that the signals is one and the same phase discriminator are supplied to enhanced whereupon the output voltage is the zv in a known proportion to this phase shift and thus to the difference see / i öen numbers.

The arrangement for carrying out the method according to the invention is characterized in that a pulse generator and two circuits are provided, each of which has a frequency divider and a generator, which are connected to a P ¹ Vi end converter, and c.ass the counters have a "• <? it <? rem input through which the various decades can be set at a certain point in time so that the setting corresponds to two numbers from which the" ifforen "is to be calculated.

For example, illustrates one of the large ".? S at the liquid level of 3 in a T container. UF should be maintained _t and the rindere? Ηη actual Fepelstsnd. Y / hen a positive difference, a device automatically operates a putt. ^ C , "5 Introduce some liquid into the container. The Pe ^ eI is here not -as physical size, but as the the T.:aß -2Kgel ~ ^ he used p number that is in a Eechner;

cfc? iird aer Sl ^ icrsgevichtsrep-pl not through a fe ^ + en zu-'rx ^ ri; dar- · t ° llt, but üur ^ h a number], which is present in a cjp- »r> n Eechne - * -. There is no problem in r. ^ TP! Calculator d \ n Ui-interference of the b ^ id ^ r. To get numbers, but ° ro different, no far never only a ^ r " ⁵ r.rh remains, IMPt only auj ⁵ " I izf »"> ie sair rurchführungun ^ niner automfiti see Gt ^ ue-

η j ι <] ■■

009850/1665

The method according to the invention results in a phv? I? Ai.: I nebe Size (electrical voltage) proportional to the difference, and so its further processing is very easy.

Another possible application arises from the following example: A Me ^ ohinenwerVaeug must cut '' in / och into a piece of gate. One of the two calculators shows the e ^ ndti ef e, 7. ^. 342 mm, while the other computer gives the lowp -. M, ir. Dpr the tool is moved so that a C is toronto when the call is made, then the * .7ert 1C, 5C mm etc. are displayed will. The device according to the invention begins numerically dip Diff r ^ enz to zäMen, namely 34? " ?? ⁹ , 29? etc., but it converts this directly into an electrical voltage. If the limit value, eg 45 mm, is reached in the predetermined limit, the movement of the tool can be slowed down to a value of 0 if r * on, it can be blocked and at the same time operated to-nn »a camouflage device or a new operation in the H ' . ^ rcMne to be started.

The numerical differences can be evaluated very advantageously by the operator if he follows the operating sequence, but they are less useful if it is a matter of deriving an actuation, for example a drive, therefrom.

The invention is explained below in conjunction with the drawing on the basis of some exemplary embodiments. Show it:

Pig. 1 a two-decade counter that has a voltage generator controls,

Fig. 2 shows a first embodiment of the arrangement according to the invention.

flg. 3 shows the course of the DC voltage at the output of the Fhasendie krielnators when the differences * between the two change Values »

Flg. 4 * i & Blfcokechaltbild, "renn ate size na eh <Jtr Zttnahae ge *

* ·· # ** «earth« oll, fig « 5 an Xleeksehaltbild of a second execution toolforfft the he»

fiiHBftn arrangement,

009850/1665 ORIGINAL BATHROOM

15881H

FIG. 6 shows a modification of the circuit according to FIG. 5.

ITaoh Fig. 1 is given a pulse train f which the input a counter is supplied, which in the present example has two decades C,, Cp and with a generator circuit G is connected, which emits a frequency f = at the output. Construction and application of such a generator sine] known.

In! '' Iff. 2 two groups connected in parallel are arranged, each of which is similar to the arrangement of FIG. 1, ie. she consists from a counter with two decades Cp, C, or C., C, and a generator G. or Gp,

Both groups are given the frequency f at one end and they are at the other end with one and the same phase discriminator D connected

In addition, every decade is treated with a device, which is shown in the picture with the switches I ₂ , I ₁ , I., I, and which allow any number from 0 to 9 to be assigned to the same decade.

The two generators G ₁ , Gp result in a frequency f or f ¹¹ 'switches Y / ortes (1/100 f ) with a voltage of the same amplitude and rectangular shape; the phase position is changed via the switches I ₁ , I ^ » Ι? ι I ^.

This arrangement is able to accomplish the task described above to release.

BATH ORIGINAL

009850/1665

1588ΊΗ

Assume that the difference between the "two numbers 35 and 15 is to be taken in an analogous" ¹⁵ OrDi. In feathers be-Lie "t-lived instant between two pulses of the Einfangsspannung include the four switches I _1, I p, _f I_ I, by the number 15 on the counter G ₁ - C ₂ and the number 35 to the counter -CU-C, is transferred.

The two numbers given to the counters take the place of the numbers that the counters currently contain; the harvest counter will thus show 15 and the other 35. Both then continue to count to 100; but the counter G _? who is 20 units rider will reach this goal sooner and generate a curve with frequency f '; when a further 20 pulses with the frequency f have arrived, G ₁ has also reached the number 100 and a curve with the frequency f * is created. The same frequencies f '· and f' are thus phase shifted from one another and in the assumed case the phase shift is Γ0 / 100 of the period.

Since the two frequencies are equal to each other, it occurs at Applying the same to the phase discriminator D a direct voltage whose value depends on the phase difference according to Preieck's law (Fig. 3) when the voltages are rectangular Have curve shape.

In other words, this means that the 7, ^r ert of the DC voltage at the output of D according to a precisely defined law of the phase shift and therefore of the difference between the two numbers that are set via the switches I ₁ , I ₂ , I ,, I .. at the moment t has been discontinued in the decades.

009850/1665 badoriqinal

⁷ '15881H

The tension on the .-. Us £ ang D can be used directly to control a Control "can be used as in the known art the appropriately demodulated voltage of a position p "Gynchro-type" is used.

"When using the control, the two numbers that represent the position to be assumed by ron" movable part anopron, in corresponding time intervals (with the Tuv ^^ - inf " before. Tinrlertens 100 irregularities of f is waited for) the "Counter C ₁ -G ₀ , and the" two numbers that indicated the position in which the movable part is located ", the counter

ieh the invention can also be single-digit Numbers or those with more: - · .Is two digits · n used who en; then only the number of counters changes

G _o »-C or C-2-0-forming components.
.2 1 t> 4

In the case of the Pig. 4 becomes the measure of the position of the "moveable." Machine part measured according to the increase. In this field, the circuit can be grounded in a simplified manner and thus can be achieve a reduction in the manufacturing costs for the arrangement, Namely, it is possible to use an auxiliary counter GA with a small capacity and to set a pulse generator GI in front of the counter C. ~ öp.

The Maßssuwachswerte be sent to the Hilfszä'hler GA ^ generates the pulse GI lietMtigt which additional Iepulae that follow with another! Clock ale the pulses of the frequency f _Q * las Jet intentionally provided because thus the simultaneity of two Ispulee to einee Loss of computation would lead.

009160/1665
BATH ORIGINAL

Fig. 5 shows a similar but expanded view " in which six-digit numbers can be processed, which e.g. correspond to the measured values of a controller.

In this case there are six series of components that each at one end with the capture of a frequency f and at the other. End in pairs with three different Pharendi r.kriminatorenDI, D2, D3 are connected.

In each line counters similar to C-, Gj and Impulrge "berGI are preprogrammed; the counters are provided with switches I-, Ip. At time t the salaries I ₁ , - I _{10 are used to set} the six digits that represent the target value and the six digits for the actual value. The phase comparison processes are carried out by the three ice criminals D ₁ , Dp, F. because every discriminator D ₁ , Dpbzw. D ^ only has to display the difference between two-digit numbers.

In addition, the three outputs D ₁ , D ₀ , Γ ~ have a lower value ("valence"; until the output of D ₁ almost reaches the Eull value, the output Dp does not need to be used, .and up to When it almost reaches zero, D does not need to be switched on ... on the other hand, each of these outputs can • be used differently, eg by driving the machine at a different speed.

Finally, the arrangement of FIG. 6 is similar to that of

Fig. 5, only a certain "superimposition" of the locked / BChledenen ZNM is provided. 009850/1665 _PAD ORIGINAL

In this case, the counter C, has the same content setting as the counter 0 ^ »and the same £" ilt for the counters'"C ₁ - and ° 5b ^{and G} ₉ a ^UnÖ ° 9 * ^{and C} 11a ^and

The less "significant digit of the first counter (i.e. the one with a lower 'value) is the most important place of the second Counter and the less significant digit of the second counter is the "most significant of the third. So you get at the output a demodulator of higher valence also the "carry over" of the demodulator of the next lower valence, which is the use the output voltages for a controller.

In this case, too, the setpoints are set using switches I ₁ -Ig and the actual values are set using switches I ₇ -I ₁₂ . The output frequency of the devices G1-G6 is

The task of the two frequency separation counters in front of the counters 0 / - Gc-U and C-ip "" G-I i "h is to determine the output frequencies to make all devices G1-G6 the same.

009850/1665

Claims (1)

15881U Claims j • · 1. ) Method for generating an analog signal which depends on the difference between two variable, occurring in digital form, characterized in that pulses of higher frequency are generated, which are fed to two frequency-dividing counters, which are on two lines parallel to each other and are connected in series with a generator which emits a signal with a rectangular waveform that two numbers are sent to this counter in an instant between two input pulses that produce a phase shift between the two signals with a square waveform that the signals are one and the same ^ Phase discriminator are fed, whereupon the output voltage is evaluated, which is in a known relationship to this phase shift and thus also to the difference between the two numbers. 2i method according to claim 1, characterized in that the difference between groups of digits that make up the two numbers to be subtracted is calculated individually and simultaneously will. 3. The method according to claims 1 and 2, characterized in that the difference between groups of digits of the two numbers is calculated so that the same digit appears in two different groups. 4. The method according to claim 1 or one of the following, characterized · characterized in that one of the two numbers is kept unchanged while the other is experiencing changes, which are measured after the increment, and that measuring that increment 009850/1665 15881U values are carried out by an auxiliary meter with a smaller capacity, the result of his readings on one of the two main, counters passes on " 5.) arrangement for performing the method according to claim 1, or one of the following, characterized in that a pulse generator nnü two circuits are provided, each of which has a frequency divider counter (CL, Gp »Gz» C ₄ ) und.einen generator ( Eq. & 2), which are connected to a phase discriminator (B), and that the counters have a further input through which the various decades can be set at a certain moment so that the setting corresponds to the two numbers, of which the difference should be calculated 009850/1665 Blank page