SU760001A1 - Method of determining the deviation of object parameters from standard value - Google Patents

Description

The invention relates to a measuring technique and analysis of the quality of parts, units and components of electrical and electronic equipment in the conditions of mass production and operation.

There is a method of element-by-element tolerance control or circuits, in which

the parameters of the controlled circuit are converted to voltage, and its control is carried out by comparing this voltage with the reference one having upper and lower permissible values [1].

The disadvantage of this method is that according to the measurement data is given only information. "Godeis" or "rejects", in addition, this method is unsuitable for multivariate analysis of electrical parameters of objects.

Also known is a parametric method of measuring the parameters of an electrical circuit with a test sample, in which, by balancing the shoulders of the bridge, read the indications that determine the desired parameter of the circuit [2].

The disadvantages of this method include low information content of measurements and the need for

The ability to conduct complex mathematical calculations to determine the remaining electrical parameters of the object characterizing it, as well as the unsuitability of this method for the multivariate analysis of the electrical parameters of the object and the reference.

The closest in technical essence to the present invention is an oscillographic method for determining magnetic characteristics, in which magnetic oscilloscope loops of reference and controlled objects connected in parallel to one power source are fed to the oscilloscope screen alternately using an electronic switch and, comparing them, judge the quality of the material controlled object [3].

The disadvantage of this method is that the combination of properties of the controlled object is determined only by the principle of “better”, and the divergence of loops, which characterizes the difference between the properties of the counter-blipped and reference objects, requires to determine the parameters of complex mathematical calculations that do not provide sufficient accuracy for

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quantitative assessment of the parameters of the controlled object; and also does not allow the prediction of the technical condition of objects in operation.

The purpose of the invention is the prediction of the technical condition of the working control object without stopping and opening, reducing the time of control and improving the measurement accuracy.

This goal is achieved by the fact that, according to the method for determining the object's parameters to be switched off from the standard, based on a comparison of the magnetic hysteresis loops of the object and the standard, powered by parallel excitation, the parameters of the difference signal of the object's and the standard's reactions are converted, for example, area, phase shift - in voltage, each of which is estimated by the η-point system, and the resulting 20 points are compared alternately with a numerical sequence atelnostyu variations sostav_lennyh based on the known properties of the aggregate deviations of the controlled object and a reference numeric sequence variation? 5 telnosti analogously obtained, determined by a combination of the controlled object.

FIG. 1 shows a device diagram illustrating a method for determining the deviation of an object's parameters from a standard; in fig. ² 30

measurement timing charts.

The device contains a controlled object 1, a standard 2, a source of excitation voltage 3, a block 4 for subtraction, a block 5 for measuring parameters, a block 6 for determining points, a scoreboard 7, and also exemplary resistors 8, 9, with the object 1 and the standard 2 being set to adjacent shoulders of the bridge, and resistors 8,

9 - in opposite shoulders, respectively. ,

Timing measurement diagrams denote ₄ θ the following plots: a - excitation voltage; b - the current in the circuit of the object, c - the current in the circuit of the standard, g - the difference signal.

The essence of the method is considered on the example of such an object of control as the throttle 1 ₄₅

UBI 40/220-ΒΘ-05194 (50 Hz, 0.43 A

SOY-P ^ 0.5, TU 16-535 601 71).

The carrier of information ’in this case is the current flowing through a hundred windings.

Given a form of the excitation signal, ₅ θ given to the choke, the nature of the reaction signal given by the current carries sufficiently complete information about the choke.

In order to visualize the factors affecting the properties of the controlled choke, $$ set the traditional parameters of the measurements of the values of its parameters: C, B, C.

Then connect the egog choke to the source

AC and fixed frequency

conduct measurements of the parameters taken from the resistor 8 (9) (fit. 2a) voltage proportional to the shape and size of the current flowing in this circuit (Fig. 2c). From the equivalent circuit (Fig. 26) it follows that due to the active and reactive resistances in the circuit there is a phase shift between the applied voltage and current (Fig. 2d). They measure the values of and _t , 'P and then divide them, respectively, into selected scale units (they introduce scale factors). Moreover, the units of scale must be chosen such that for a given type of chokes the magnitude of .'Р does not exceed 10 units. Thus, assess the parameters and _u , F on a 10-point system.

In the above example (Fig. 2c), for and _{t is} obtained VI) points, and for f - VI points. If these two figures are taken together, then, the resulting variation of points is equivalent to the values of B, B, C for this throttle. Obviously, a change in the values of any parameter c, B, C changes the variation of points, since the values change

However, to obtain accurate information on specific values of B, B, C of controlled chokes, it is necessary to find the dependence of the points on the values of B, B, C. Such dependence is found in a practical way, that is, the parameters B, B, C of the controlled objects are precisely measured and recorded under the resulting variation of points. Thus accumulate information that can be presented in the form of a table or directory.

Three measured parameters with a 10-point estimate give the number of variations 10 *, with which you can detect and record a wide variety of properties of controlled objects.

To determine the totality of properties (quality) of controlled objects, as well as determine the influence of external factors on them, they use a differential method of measurement and receive an electrical signal that carries information only from the sets of features that distinguish the controlled object from the standard. However, the shape of the difference ^ signal of the reactions of the object 'and ’of the standard' can be very diverse and also carries information, therefore, it is necessary to enter another measurable parameter — the area of the difference signal 5.

The same type of choke is used as a reference, which has proven itself to work. The reaction signals of both throttles of object 1 and standard 2, which are fed in parallel from the excitation source 3 and connected in series with the reference resistor 8 (9), are subtracted algebraically in block 4,

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and the parameters of the received differential signal are measured in block 5. The parameters include, for example, the instantaneous voltage of the difference signal (Fig. 2d) at times F ^ and, corresponding to

the passage of the exciting voltage from source 3, respectively, through ”0” and “max” area 5 of the differential signal (Fig. 2d) for the period, phase shift of the signals of object 1 and reference 2 (Fig. 26, c), recorded during their passage through ” 0 ”at times and from negative half period to positive.

Each of the parameters of the differential continuous signal is converted into voltage, which is estimated, for example, by an eight-point system, in block 6 for determining the points (B-, B ^, B ^, B ^) consisting, for example, of a converter and a decoder on eight outputs, connected to the scoreboard 7.

The measured parameter, converted into an electrical signal of a score, lights up on the board 7 one of eight light signals, which characterizes the degree of deviation of the measured parameter from the reference by an eight-point rating system.

According to the obtained variation of points, using the catalog compiled from the known deviations of parameters of controlled objects and the variations obtained for them, determine the set of properties that distinguish the controlled object from the standard.

Under the conditions of mass production with continuous non-destructive testing, the proposed method allows for a comparative analysis of the parameters of the objects associated with identifying the operations "supplying defects" in them, automating the monitoring process, accumulating information about the technical condition of the monitoring objects and reusing it, improving the measurement accuracy, determined

share the impact of external factors, predict the technical condition of objects in operation.

Claims (1)

Claim The method of determining the deviation of the object's parameters from the standard, based on a comparison of the magnetic hysteresis loops of the object and the standard, with their parallel excitation, which is different in that, in order to predict the technical condition of the working control object without stopping it, and opening it, reducing the monitoring time and increasing measurement accuracy, the parameters of the difference signal of the reactions of the object and the standard are converted, for example, the magnitude of the instantaneous values at fixed points in time, area, phase shift - in conjugation, each of which is evaluated by η-point system, and the resulting variation points successively compared with variations numerical sequence made based on the known properties of the aggregate deviations of the controlled object reference and the variation of a numerical sequence, a similarly prepared set of determined properties of the controlled object.