CS220410B1 - Method of detecting periodic variations of sensing signals - Google Patents

Abstract

The method is used for determining periodic fluctuations of the transverse dimension of a running yarn, particularly on open-end spinning machines for detecting the moiré effect. The electrical scanning signal (F') is transformed into a sequence of needle pulses (S'); this pulse sequence (S') is compared with a reference pulse sequence (Z') of a particular preselected period (p). The mutual phase relationship of the pulse sequences (S' and Z') is changed in small steps, the number of coincidences of pulses within a number of such steps assuming either a maximum or not indicating any pronounced maximum. Two criteria for determining a maximum are specified. The first criterion is met when the number for T exceeds a particular minimum value; the second criterion applies when the sum of such excessive T values in successive test steps is greater than a further minimum value. <IMAGE>

Description

The present invention relates to a method for detecting periodically susceptible signal variations, representing instantaneous values of the transverse dimensional variation of a passing infinite formation, in particular a textile fiber sensing signal.

[0003] A method and apparatus for detecting periodic phenomena in various quantities, in particular in the substance cross-section, are already known from the British Patent Specification No. 795,808. This method is based on the frequency analysis of the electrical signal to represent the time course of the quantity. However, since such an electrical signal normally normalizes itself in addition to the frequencies characteristic for the periodic phenomena, and the still wide continuous frequency band, which is associated with non-periodic events as well as irregular transient phenomena, it will hardly be possible to filter safely a periodic signal from the original electrical signal.

The task of finding ^{y dy} te is caused vytvoMt zJiěUvvání ^ ^b ^ Rio CTY is sl ^ ^ ^^ yní ЬэИsání sensing signal, Jeni umooňujc safe determining these variations and their periodicity.

This object is achieved according to the invention in that a portion of a certain length of the fiber signal is converted by a sequence of signal pulses, being peaks of the fiber signal exceeding a certain threshold, and the signal pulse train is sequentially sensed by a sequence of reference pulses. the pre-selected period, the phase position is changed in successive steps of a certain length, while the number of coincidences of the individual impulses from the sequence of signal imptubs and the sequence of reference pulses are determined for each step.

The enormous simplification in the mere apparatus given in this way results from the fact that not the original electrical signal as such, but the pulse train derived therefrom, is taken as the basis for further investigation. The term pulse train is intended to denote a series of non-pulsed Si not necessarily periodically successive pulses, as opposed to the periodic pulse train. Another advantage is that, in this pulse train, the periodic phenomena of the original signal appear in a simplified form and the pause can be detected based on its periodicity. This will enhance the ^e spoSehlivsst determining naaoUk periodic phenomena, ie the days and capturing such periodic · Phenomena, by accounting Jei in the original signal is relatively slight and anppitudu Already there neooJevvUí even when visual evaluation.

A special area of the novel method is to find so-called 'soggy' in twisted yarns, where the jerks of the fluctuations in thickness with as little as epic are safely caught by conventional yarn cleaning methods and devices.

In the násilnícím ^ Izieu illustrate a new ^{P b} uso а got nothing ^ ^ cle APPARATUS FOR ^{IMPLEMENTATION} form of embodiment for pomooi drawings, in which. Figure la is shown by signal £ 2 form fibers which přcdstavuJc · fluctuation cross section or diameter of the passing Fig. 1b slcd S 'of signal pulses, which represent the junction points of the fiber signal threshold Fi, Fig. 1c slcd Z' of reference pulses from needle pulses Zn · of a preselected period a, Fig. From the reference pulses by. dn. 1c shows a pulse slcd having an increased pulse period by dp relative to the reference pulse train Z &apos;. 2 shows a block diagram of an electronic device: FIG. to implement the method ·

The method sc will make sure that from the sum of all the highs, the fluctuations in the cross-section or the diameter of the passing filament will only capture periodic fluctuations. For this purpose, the SC neJprvc ZC signal F * fiber of Fig. La, · the obtained sensing fiber and the monitor okammitá fluctuations manhole ^or ^ correlation oc ^ ozuJc SLC ^d S1-pulse ^P a ^d-c in FIG. ¹ b, Jc ^ ^p pose a ^{PI No} F ky · ^k for VLA piřekračnící beaten ra ^{p h} verifies hoánotu thus poring sequence ^{s' ig} n ^a ^ n ^ c ^h pulse · Jcni consists of pulses stcJné amppitudy but different duration, RcSp. of different widths, sc fits ^ a ^ i ^^^ i ^^^ iá. In order to sort out the sequence S * of the signal pulses periodically. Sc pop-up pulses P1 and P6, etc., also having other pulses coming from the normal static sixth order of the yarn in question, are sc slcd S *. signal pulses in the first step through. slcdu Z_1 reference pulses

220 * 410

E and limited β of such needle pulses. In the next steps successively assessed phase sequence Z '^ reference pulses ^for the smaller ^alkyl ro ro ^P dn and each of t ^and who produced. ^with ice pulse number koinc ^ID Enciu Use of a specific sequence in ^the S * signals on one side and the reference pulse sequence Z on the other. From the course of the number of coincidences, it is possible to determine whether there is * periodicity on the basis of certain criteria, which will be described in more detail. If the first series of tests with an unchanged period of p pulses, consisting of a number of such steps, does not result in any result, the method may be repeated with one or more other impulses of pulses, each showing an altered p-period of pulses. However, the variation of the period length and the pulses need only apply to those obabats that, according to experience, are suitable for the occurrence of periodic fluctuations. For example, in the twisted yarn test, the period is roughly equal to the rotor perimeter, so that the value of this perimeter can be taken as the basis for the first test series. In the further operation of the spinning machine, the value of the pulse period resulting from the experience, i.e. the previous production tests, can be taken as the basis.

Since one series of tests can be carried out over a very short period of time for the duration of the signal pulse train S ', it is possible to query one and the same signal pulse train during operation on a tsxtin machine, for example a rotoo spinning machine. several successive series of tests with unchanged periods of impulses. The shift of the sequence of Z * reference pulses by one step dn is shown in Fig. 1d and the change - here increase - of the pulse period length by one increment dp is shown in Fig. 1e.

In detail, FIG. this; In Fig. 1a, the * line U represents the temporal mean value of the cross-section or diameter of the fiber, while the dashed line 'determines the threshold value which serves as the basis for the formation of the S * signal pulse train. According to Fig. 1b, the single pulses Sm (m = 1, 2, 3, ...) of the signal pulse train s are determined by the time coordinates g and their leading edges and em of their leading edges, measured from the non-continuous time zero point t0. The needle pulses Zn of the reference pulse train Z * are determined by the time order of the first needle pulses Z1 and always by an integer multiple of the period p of the pulses. Fig. 1d shows the phase shift of the reference pulse train Z by only one step dn; ^during the interrogation process, the phase shift varies continuously .o steps dn. 2dn. 3dn. ... As a step άπ, a small fraction of the p-period can be increased, for example in the range of 0.1 to 0.01 p ·

Alternatively, the period p of the pulses of the three-point variations can be multiplied by increments of the increment dp. . wherein for each changed period p + dp. p + 2dp. ... repeats the procedure described above.

The selection of the threshold according to FIG. 1a is effected by automatic adjustment so that, for the ^S pulse scan, the ratio of the pulse dwell time to the pause interval between pulses is, for example, about 10 percent.

In order to recognize the periodic series of pulses within the S * signal pulse train, a period of at least a duration such as to capture about 10 periods can be selected. For interrogation, one of the S * signal pulses or the Z * reference pulses, which shifts when polling against the other, should contain at least one period more. Thus, a fixed portion of * the sequence of * signal pulses was resolved. a length of 10 cycles through a sequence of reference pulses Z * has the SLS ^d Z ^ h * Reference Osáhnout pulse ^and LCS ^p o ⁿ 11 ^ ^ riod ^and ak.

The electronic device shown in FIG. 2 serves to carry out the special form of the method according to the invention. It consists of an evaluation part 1 to 1 in which it is formed by means of a signal F. ' fibers sequence S *. of signal impulses, from the minicomputer Z, in which the sequence of signal pulses S * is tested in terms of periodic occurrence of pulses and signaling device 14.

The sensing device 6 is provided for detecting the passing filament F. This can be provided in a known manner with a capacitive or optoslectronic converter whose measuring field is a fiber

F leads. The sensing device 6 delivers a sensing signal that represents the timing of the diameter or cross-section of the fiber F. The sensed signal is converted in an amplifier Z, for example a shear amplifier, into a fiber signal F shown in FIG.

The fiber signal F 'is applied in the evaluation circuit J to the signal input of the compactor 6, to which the second input is supplied with a bias V, which determines the threshold value · · in FIG. The amount of bias is controlled by a feedback circuit connected to the output of the coil. This feedback circuit consists of a series connection of the integrator g and the DC amplifier 6. At the output of the compactor 6, a sequence of S 'signals as shown in FIG. Upon appropriate setting of the gain factor on the stenossomer amplifier 6, the threshold g is adjusted automatically on the compactor 6 so as to achieve a certain ratio between mean pulse duration and mean pause having, for example, 1:10 or 10% in the signal pulse train.

^{Sl d} e ^S 'signal ^I ^ ^m ^ ^s ul_s at ^{the Ada} l s ^ig n ^A1 St. Ame ^{SF E} i £ ^p in the ^BE values of ^d of temporal sornřadnic as EM · see Fig. 1b. The reference memory g stores the sequence Z 'of the reference pulses of Fig. 1c in the form of time coordinates d + ko (k = 0, 1, 2, 3, ...). In the digital comparator Ю, the signal pulse train S 'is compared with the reference pulse train Z', ie it is tested whether the relationship am <d + is satisfied for the single-time incremented gak values within a preselected signal pulse train S of about 10 periods. kp <em;

if this is the case, then the coincidences are counted.

Furthermore, the counter 11 is determined by the number T of the incidences, i.e., the pulse train S is interrogated and compared with a predetermined minimum number of Tg. As the first criterion for the occurrence of a periodic defective sample, as represented by the moiré effect, it is assumed that the * T Tm condition is met.

The smallest number of Tm coincidences should be greater than the average of all T-coincidences in the test series.

For a fiber period F ' which includes 10 periods, when the moiré occurs, the T-counts are about between 8 and 11, without moiré. comparable numbers of T colonies between about 1 and 5 · The smallest number of T m coincidences in this case may be 7.

Further, a second crystal is received to increase the accuracy of the moiré detection. This second criterion results from the following: As soon as the first in the polling process is satisfied, the successor T must be counted in succession until again the smallest number of Tm coincidences is reached; if the sum of S (T) is greater than the predetermined smallest value of Sm (T), then the second is fulfilled. In this case, a darkening pulse is sent to the signaling device 14, which can be designed as a counter.

If the first or even both criteria are not met, the value of the reference pulse period £ changes in the reference memory g by the increment dp and the interrogation procedure explained above is repeated with the new values. This is continued until a moiré sample is found on the basis of the second criterion or until the β period has gradually changed over the entire area where, according to more experienced periodic defects, it is possible to ·

The entire program described is controlled by the control unit Ц. in whose command flame! are defined program steps and numeric constants Tg Smitt. · g, HIA, f ИМЛо (the HD magnification steps dn vzrůsíabící value g, and thus the three-phase ^p about Loh ^Y needle im ^p ULS ^of Zn ^ du Z * rifirinta Impulse equals to individual pulses The sum of the signal pulses sequence and Hd means an increase in the duration of the period during a stepwise change by increments of dp.

Furthermore, a clock generator 12 is provided which determines the clock for the single-pass program steps of the control unit 13. «

The table below shows a numerical example to illustrate the method described. Behind the base serving the fiber F for the fiber signal F 'is a yarn of cotton yarn spun with an open end with a slightly expressed mooré. The length of the yarn section, repp, of the yarn section was equal to eleven times the circumference of the spinning motor groove, and thus comprised eleven periods. The sequence Z * of reference pulses comprised ten periods,, therefore eleven needle impulses Zn · Here, therefore, the sequence of reference pulses Z'_ was questioned by sequence S * of signal pulses · The increase Hd corresponded to one period length and took place in 60 . by the number of coincidences T. 7 ·

n = 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Dec 16 17 18 19 20 T = 2 3 2 2 1 2 2 1 2 3 2 1 2 3 2 3 2 3 4 5 4 S (T) = 0 ... n = 21 22nd 23 24 25 26 27 Mar: 28 29 30 31 32 33 34 35 36 37 38 39 40 T 8 4 4 5 5 6 5 4 4 5 5 5 4 4 4 3 2 3 3 2 1 S (T) = 0 n = 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 T = 4 2 3 3 3 2 3 6 5 5 6 9 10 11 10 10 9 8 7 5

S (T)

Here, the number of query steps in the increments of the day in the second row is given for each of these steps the determined number of T coincidences and in the third row the sum of S (T) for the successive steps for which the first criteria T-Tm are met. , Tm = 7 · This sum is for the eight consecutive steps 74, so you can safely assume the ytО ^ ё capture ·

Otherwise there is the inventive method restricted to shapes impiUsů shown in FIG · 1 even when Voh especially ^E on the Jenny SLE ^chloride with 'sig ^ turate-pulses and a sequence ^of Z * referentoí ^ imptúLs-rectangular pulse and the second pulse for example, the signal pulse train S * may consist of needle pulses, which are then determined, for example, to form the center line of the center of gravity of the signal peaks shown in FIG. 1a and exceeding the threshold value While the sequence of reference reference impulses consists of rectangular pulses of the same defined duration, at a duration ratio. toward the gap between pulses impiú.sy about 1: 10, as well ^{will give} a ^P ro s ¹ * ^s ^ a ^ ^ ^ AIM pulses ·

Claims (9)

1 · A method of detecting periodically the incidence-measuring-variation sensing signal representative of the instantaneous value fluctuation transversal dimension u of passing endless formation, in particular scanning signal textile fibers vyzm-bore formed in the section of certain length signal in ^LA KNA revolutionized SLE ^{d (} s ^{*) g} a n ^{d and} ln c ^h a pulse, ^Z represents a tip of ^g n ^and LU (R *) fibers přestuppuící certain threshold value (s) and the sequence (s') is sensed signal impiu.sů ^{of p} ostupn sequence ^(Z>) reference pulses ^^ ^ o ^ edzvoíené ^p eriod ^{(p) j} is jcch ^f ^ féízová task is changing in successive increments successors of a certain length (DN) přčeemž for each step is ^determined number U is ( T) toincifoncí jetoot-solid ductile-pulses of a sequence ^{(S *) of} N ^^ ^a ^ n ^ c ^h a pulse sequence (Z #) reference pulse · 220410 6 2. The method of claim 1, wherein the coincidence counts (T) that satisfy the condition T Tm for a predetermined minimum value (Tm) by coincidence. 3. The method according to claim 2, characterized ⁱⁿ that the sum S (T) is formed for the values Τέ Tm, which are carried out in successive steps. Method according to one of Claims 1 to 3, characterized in that the threshold value (S) is increased such that in the signal pulse train (S *) the ratio of mean pulse duration to mean pause between pulses is 0.05 to 0, 1. Caused by the fifth ^{b b} o ^d u 1 ^ ^ ζηβύ ίοί in, ^{that the} certain e USE lty ^ gn ^ si-Lu ^{(X F)} of the fiber comprises at least ten periods (p) předzvoleného duration. Sixth Způsoh by ^b o ^d u 1, characterized in, ^that the IE ⁱⁿ particular discharge pulses ^{s (S m)} in SLE ^d u ^{(S #)} of signal pulses maai auplitudu same. Seventh USO ^Zp ^ ^b according to claim 1, wzna ^ said non ^from an SLE with ^{d (z /)} ^ h impiuLsů reference to which is made behind následuuící steps vooí first series of tests the same period (P). 8. A method according to claim 5 or 7, characterized in that a period (p) equal to the length of the circumference of the rotor groove is selected for testing open-end spinning yarns. 9. The method of claim 1, wherein the length (dn) of the successive steps is a fraction, for example one-sixth, of the selected period (p).