SU385290A1 - FREQUENCY-PULSE FUNCTIONAL CONVERTER - Google Patents

Description

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The invention relates to computing and can be used in computing devices processing pulse frequency information.

A pulse frequency function device is known that implements a piecewise linear approximation method, in which the original function is replaced in each interval with a corresponding segment of a straight line.

The known device comprises an interval determining unit, a subtractor, a multiplying cell, a pulse frequency tracking system, AND and OR logic.

The disadvantages of this device are cumbersome, high cost of equipment and limited logical capabilities.

The aim of the invention is to reduce the number of elements of the frequency-pulse function converter.

For this, in it, the outputs of the subtraction circuit subtraction circuit blocks are connected via two OR circuits to the first multiplying inputs of multiplying-dividing cells, the separating inputs of which are connected to the output of the frequency sensor, and the outputs via the third logic circuit OR to the input of the following system; the second multiplying inputs of multiplying cells are connected via two logical circuits OR to the outputs of a group of logic circuits AND, whose pulse inputs are connected to the outputs of the Frequency Sensor, and the potential inputs are connected to the outputs of the decoder of the interval determining unit.

FIG. i shows a pulse frequency function converter; in fig. 2, a - piecewise linear approximation of the Lagrange polynomial; in fig. 2, b - construction of a given piecewise broken line from the sum of triangular functions.

The converter (Fig. 1) contains a block for determining the interval /, consisting of two

subtraction circuits 2, logic circuits "OR 3, control circuits for counting the number of intervals 4, logic circuits" AND 5, reversible counter 6 and decoder 7, two logic circuits "OR 8, two multiplying-dividing cells 9, group of logic circuits" AND 10 , logic circuits OR L and 12, frequency-pulse tracking system 13 and frequency sensors 14 and 15. The outputs of the subtraction circuits 2 of the interval determination unit / are connected to the inputs of the count control circuit of the number of intervals 4, and are also pairwise connected to the logic circuits OR whose outputs are connected to PL zhitelnym inputs pl

separator cells 9. It divides 3 inputs of cells 9 connected to a frequency sensor for: and other multiplying inputs to the outputs of logic circuits OR 11, each of which combines a group of logic circuits “AND 10. Pulse inputs of circuits are connected to outputs frequency sensors 14 and 15 FOU.ZJ and Fou (2j ± i), and potential ones to the outputs of the decoder 7. The outputs of the multiplying-dividing cells 9 are connected to the clock-10 input of the full-pulse tracking system 13 via logic circuits OR 12. One of the inputs of both subtraction schemes 2 is connected to the input of the FX device, and the second inputs of the connection Outputs of logic circuits "OR 3" combining outputs of logic-15 and schemes of circuit "And 5. Pulse inputs of circuits" And 5 are connected to the outputs of the sensor (x - (- Xp} (x - xi) ... {x - () () ... (Xk In practice, to simulate an interpolating factor, fj (q :) use its piecewise linear approximation. The type of the Lagrange polynomial and its 25 approximation are shown in Fig. 2, a. The bell-shaped curve of the product F (Xi) - (h (x) is replaced by the approximating piecewise broken function a (x), which we will call in the following a "triangular 30 function or a - function. The triangular function varies linearly with II t t over the interval from (k-1) -th to L-th node and from -th to () -To node and is equal to zero in all other intervals, where and 35. / О for x Xk-i „(w. B (x - Xk-i) for jCftJi π: JCft (Xi, i - x) for Q with (2) J b (Xk -Xk-i), b -. Xk-xk-i If a series of interpolation nodes is specified (a series of points on the xy plane), then the polynomial 45 "y S / (A;) 2 ()" ft (x) (3) ° expresses a polyline consisting of segments direct connecting adjacent points. On Fig. 2, b, the construction of a given piecewise broken line from the sum of triangular functions is shown in accordance with expressions (2), (3). The functional converter based on the Lagrange interpolation polynomial 55 has high efficiency and universality and the visibility of the image function. The body works as follows .60 The input arguments x in the form of a pulse repetition frequency F (x) are fed to one of the inputs of both subtracting circuits 2 of the interval determining unit /. The second input of one of them is supplied with reference frequencies, mode-65 4 frequencies 15 modeling border interval with odd (Fou.i, op-z, - .., / on (2y ± i)) and with even (/ op.2, Pon-it,) numbers, and potential inputs - with the decoder outputs 7. In the basis for constructing a functional converter is based on the Lagrange polynomial method in a piecewise linear form, since the Lagrange polynomial consists of nnye values "I1YA function F (Xk) nodes t. e. the coefficients F (xh) are approximated ordinates (x) curve and, consequently, they can be most simply calculated. This makes it possible to directly and independently set the function values in the interpolation nodes. In the Lagrange polynomial, the interpolating factor fy (l :) has the following form: x-1)) (x - Xk i g) ... (d: - Xn), Xk-l) (Xk-Xk l} ... { Xk-Xn) are the limiting intervals with odd (opl, op-s ... - op-sz)), and the other with even (f op. A, op 4 ... Fou-ii) numbers (fig. one)-. The interval definition block / determines at each current time the interval in which the value of the input argument is found. (The scope of the argument is split into intervals). For each value of the FX frequency, it determines the boundaries of the intervals Fon-zj and Fon. (2j ± i) such that P to K on.2j -S./ - 45. l on. (2 / ± l)) i x j i and, in accordance with the slot code, controls the switching of frequencies that simulate the ordinates of the function in even Fyzj and odd fv (2j ± i) interpolation nodes. When the value of the input argument passes from one interval to another, differential frequency pulses are alternately formed at one of the outputs of each subtraction circuit 2. This sequence is determined by the sign of the difference in frequencies at their inputs. Thus, in the interval from the outputs of the subtraction circuit 2, an increasing (A-i) and decreasing Fon are output. the difference. When switching to the next interval Xh x X (), the difference frequencies of opposite signs Fon- (k + i) -FX and FX-Fon-k are formed at the other outputs of the subtraction circuits 2. Combining the logic circuits OR 8 output lines of each of the subtraction circuits 2 allows em on each interval have two differences: increasing and decreasing. The outputs of the logic circuits "OR 8" are connected to one of the multiplying inputs of the multiplying-dividing cells 9, the divided inputs of which are fed by the frequency j YES: - -:, (4) on. (A-i) and on. the second multiplicative inputs are frequencies and Fy (2i ± i), which simulate the specified values of the ordinates in even and odd interpolations. Thus, the use of multiplex-division cells 9 allows the image of any "triangle", multiplying the element of the triangular functions "r (l) by the specified ordinates. On the interval X (h-) from the outputs 9, the results of multiplication operations in the form of packs of a C-Fon pulse are output. k-Fr Fy (k-i), ra (k-l) - op. ft-fon. (ft-I) P FX-on (ft-l) Fon.k FQn () Summarize the results of expressions (5 on the logic element OR 12, the floor is a segment of the straight line Fon ft - FX pI FI (X) Gu () + Foa .k- Fon (il) FX - Fon (ft-i) Fan k - Fon (ft -1) simulating the function F (x) on inte. On the interval the sum of the function P Fonlk-, I) - FC Fon (kl) - Fon.k FX - on. fti Pci (ft + 1) on (ft-11) - Fon. ft From expressions (6) and (9) it can be seen that with a move to the adjacent interval one of the ficientop (Fy (Zj ± .i)) should not change. In the device (Fig. 1), this was taken into account when building the decoder 7. The result of the summation - see expression (7) - from the output of the logic circuit "OR // is fed to the positive input of the frequency-pulse tracking system 13. Object of the invention containing an interval determining unit with two subtraction circuits and a decoder, two multiplier-divider cells, frequency sensors, a tracking system, AND and OR logic, characterized in that, to simplify the converter, the outputs of the circuits are subtracted and the interval determining unit are connected via two OR circuits to the first multiplying inputs of multiplying-dividing cells, the separating inputs of which are connected to the output of the frequency sensor, and the outputs via the third OR circuit to the input of the following system; the second multiplying inputs of multiplying-dividing cells are connected via two logical circuits OR to the outputs of a group of logic circuits AND, the pulse inputs of which are connected to the outputs of the frequency sensor, and the potential inputs are connected to the outputs of the decoder of the interval determining unit.

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