SU492882A1 - Median device - Google Patents

Description

(54-) DEVICE FOR .DEFINITION MEDIANS

pulse generator 12 and the first element And 13.

Comparison unit 1 serves to obtain the difference 4X (t) XCt) - U (n and is connected to the Schmidt trigger 2, the plus arm of which is connected to the first inputs of the And 3 and 4 elements and the minus one to the first inputs of the And 5 and 6 elements. And 3 and 5 are connected to the (+) and O (-) trigger of the sign 7, respectively, the unit output of which is connected to the second input of the AND 4 element and the first input of the code-voltage converter 8, and the zero output to the second input of the AND 6 element The outputs of circuits 4 and 6 are connected to the second and third inputs of the element OR 9, the output of which is: A circuit with inputs of an E 1O element and with a folding bus of the reversible counter 11. The output of the 1O circuit is connected to the readout of the counter 11 whose counting input is connected to the output of the pulse generator 12.

The zero outputs of all bit triggers of counter 11 are connected to the inputs of the element I 13, and the single outputs of the higher n of the trigger triggers TO the inputs of the 2-t + i converter 8. The low-order bits of the counter 11 serve to smooth the random process X (t), and the high tn bits to determine the code for the median value. The output of the circuit 13 is connected to the second inputs of the circuits 3 and 5 and to the first input of the circuit 9. The circuit 13 serves to fix the zero state of the counter 11. You-: the converter 8 running is connected to the second input of the comparison circuit 1. The converter 8 serves to convert the code received in the upper bits of the counter 11, in the appropriate voltage.

The pulse generator 12 serves to fill the reversible counter with 11 and pulses during the process analysis.

The Schmidt trigger 2, the trigger 7 characters, the logic circuits 3, 4, 5, 6, 9 and Yu form a sign circuit that is designed to determine the mode of operation and the sign of the contents of the counter 11. With this scheme, the contents of the reversible counter are in the forward code for both positive and negative values.

From the definition of a median it follows that the median of a random function X (| g) refers to such a fungation Me, for which Pl, (t)) M € or the time during which the random process takes

a value greater or less than the median (see FIG. 2) should be equal to

(one)

51 d

KG

Where

(i - u, ..., -)

At, i;., T.

If to estimate the interval / iti, fill it with pulses of a constant frequency f .., then during the time D /; will get. / proportional pulses

time D t; and instead of equality (1)

no-

and instead of equality we get equality

W

(2)

2k-1

K: i

OR

-Z Wg, -, -0

: „.Л- ...

For symmetric often found in practice, the laws of distribution of random functions (for example, normal, uniform) the value of the median coincides with the value of the mathematical expectation, therefore the definition for such processes of the median is equivalent to the determination of the mathematical expectation.

The device works as follows: a random signal is fed to the input of the comparison unit 1, where the comparison takes place. signal X (t) with the reference voltage received from the output of converter 8, since at the initial moment the voltage at the output of converter 8 is zero, X (i) is directly fed to the input of Schmidt trigger 2. For definiteness, assume that X ( ) has a positive (negative) instantaneous value, then there is a high potential on the plugs (minus) arm of Schmidt’s trigger 2, which is fed to the first input of circuit 3 (5). Since the reversible counter is initially in the zero position, in the code of circuit 13 there is a signal which, together with the positive (minus) signal of the Schmidt trigger 2, will output the circuit 3 (5) signal that will set the trigger 7 of the sign 7 to the state ( O) i.e. + (-). The signal at the output of the circuit through the circuit 9 will set the counter 11 in the add mode and the pulse supplied to the counting input of the counter 11 will write one into the counter, which will lock the circuit 13 and the resolution from the circuit 3 (5) and 9 will be removed, but by this time the trigger 7 is already in the + (-) state and together with trigger 2, which is also in the positive (minus) state, forms a signal at the output of circuit 4 (6}) which, through the circuit

 I.

Claims (1)

.1 9 is fed to the folding bus of counter 11. The contents of counter 11 will increase and a moment will come when counter 11 will receive 2 pulses and in the younger bit of the most significant ones (the digit of counter 11 will turn on the input of the converter 8, at the output of which a single step of the reference voltage of the corresponding polarity U is generated - “: on voltage is fed to the input of the comparator unit 1. The process will continue similarly described, only with the difference that the trigger 2 input will already be input signal l X (t) - Dm X (t). As soon as X (t) instead of - (J changes its sign. in this case becomes negative (positive), trigger 2 is transferred, and oppositely, the resolution is removed from scheme 4 ( 6), from the input of the checker 9 and from the code of the 1O circuit, you send a signal to the subtraction bus 11. If the value of the process median is positive, then the addition mode over time will prevail over the addition mode time and the content t of the most significant bits of counter 11 will increase until until the contents of these bits become equal to the median value .. When will m The equality element will fulfill condition (2), i.e., the algebraic sum of the number of pulses N received at the counter. Will fluctuate in the range of .Z. which is placed in the lower order bits of the counter, and the contents of the higher order rrl bits will not change. The number of low bits tl of the counter and the frequency / generator 12 is selected depending on the low frequency component of the spectrum of the random process, since the code-voltage converter should not follow the random process instantly, but only monitor its average smoothed by value. After condition (2) is met, the value. the medians will be recorded in P1 higher bits of the counter. If the median estimate does not exactly coincide with the true value, then the output at the output will oscillate with an amplitude equal to a single step with a rather large period. The device allows the output to take the digital value of the median, as well as the value of analog form in the form of voltage. In addition, the device operates as a voltage converter in a code of slowly varying voltages. Using the proposed device, it is possible to center a random process, and a centered random process is obtained (after a transient) between the width of input 1 and output 3. The process analysis time is determined by the duration of the pulse generators. Invention The device for determining the median containing reversible the counter, the first P of the bit outputs of which are connected to the inputs of the first element, the last t of the bit outputs to the inputs of the code-voltage converter correspond venno and count input, - a pulse generator vhodu 1, characterized in that it comprises a comparator, a first input of which is connected in order to simplify the device and expansion functionality. with the input of the device, and the second input with the output of the code-voltage converter, Schmidt trigger, the input of which is connected to the output of the comparison unit, the second and third elements ft, the first inputs of which are connected to the outputs of the Schmidt trigger, respectively, and the second inputs with the stroke of the first element P, the trigger of the sign, whose inputs are connected to the outputs of the second and third elements P / respectively, the fourth and fifth elements fl 1 the first inputs of which are connected to the outputs of the Schmidt trigger, respectively, and the second inputs to the outputs trigger character respectively, the first i output of which is connected to the first i input of the code-voltage converter is an OR element, whose inputs are connected to the outputs of the first, fourth and fifth elements of L /, respectively, and the output with the summing input of a reversible counter, and the element NOT, the input of which is under, is connected to the output of the element OR, and the output to the subtractive input of the reversible counter.