SU650226A1 - Analogue-discrete functional device - Google Patents

Description

I.

An analog-to-discrete functional device is intended for use in computing and information-measuring equipment.

A device for analog-to-discrete increment transformations is known, comprising a subtraction unit, an analog-to-digital converter with a stepped approximation, a bridge function generator consisting of a shock excitation generator, an electronic switch, keys, and a control unit 1.

In this device, the bridge function generator tunes to one, well-defined relationship. This limits the capabilities of the device. In addition, the sequence of increments is approximated by stepwise approximation. This requires a large number of approximation sites.

The purpose of the invention is to extend the functionality (working with the input signal, the mathematical expectation of which is unknown), as well as reducing the redundancy of samples.

The goal is achieved by the fact that in an analog-discrete functional device containing a control unit, a subtraction unit, the first input of which is connected to the input signal bus, and the second

input - to the control unit, an analog-to-digital converter, the control input of which is connected to the control unit, and the output - to the input of the switch, the second input of which is connected to the control unit, a memory block, a fixation unit, an additional switch, a code converter for example linear and functional converter, the control inputs of which

connected to the control unit, the output of the subtraction unit is connected to the input of the analog-digital converter through the fixation unit, and the output of the switchboard through the memory unit, additional switch, code-to-voltage converter and functional converter to the third input of the subtractor.

The analog-to-discrete functional device is also characterized in that the functional transducer consists of two series-connected integrators. Pa figs. 1 shows a block diagram of an analog-discrete functional device; in fig. 2 is a diagram explaining

his work.

The analog-discrete functional device contains a functional converter 1, consisting of integrators 2 and 3, a converter 4 of code into voltage,

switch 5, block 6 subtraction, block 7

fixing, analog-to-digital converter 8 with a stepped approximation, switch 9, memory block 10, control block 11. The output of the switch 5 is the output of the device.

Before the operation of the analog-discrete functional device, it is necessary to set the initial data through the control unit 11: set initial conditions on integrators 2 and 3 of the functional converter 1; write zeros in all cells of memory block 10; set the sampling rate / disc; set the gain factor K. in block 6 subtraction.

According to the "Start / Arrival" signal, the switch 5, in series with the frequency / 1 / drive, sends codes from the memory block 10 to the input of converter 4. From the output of converter 4, the voltage corresponding to the code at its input is fed to the input of converter 1 Since in the initial, first sampling cycle, zeroes were written in all cells of the memory block, the output voltage of the converter 1 (the output of the integrator 2) is removed, the feedback voltage UQ.C. varying linearly

 .with ycg + lo,

where ats is the set initial value

at the output of the integrator 3; oh - set initial value

at the output of the integrator 2. The input signal t / Bx is fed to the first input of the subtracting unit 6, the voltage t / o.o is applied to its second input. from the output of the transducer 1. At the output of block 6 there is a mismatch L (see Fig. 2)

i + (.c) where -, - - a ,.

This mismatch through period 1 -

after the start of the cycle, the readout is remembered by the fixing unit 7. The voltage value AI stored at the time of the analog-to-digital conversion is fed to the input of the converter 8. At the output of the converter 8, a code Ni is obtained corresponding to the value of voltage A. This code through the switch 9 is recorded in the first cell of the block 10. This completes the removal of the first sample. After the arrival of the second frequency pulse / diokr, the second reading cycle begins. Switch 5 in series, starting from the first cell of memory block 10, supplies codes with frequency fi, to the input of converter 4 codes to voltage. At its output 60 of, there are voltage values AI for a time Gj and then zero values. These voltages are applied to the input of converter 1. At the output of converter 1, time T

- four

O., / + a ",.

Designating

G.-f.

we can write

о.с «aif + aiiZ + aoi.

At time 1, the integrators 2 and 3 of converter 1 are set to new initial values.

After time 2Г1 from the beginning of the reference cycle or through time TI, after establishing new initial conditions on integrators 2 and 3, the output of the subtraction unit 6 is the voltage A2 (see. Fig. 2)

, (,.,} K- +

+ (input, aL, o) / C + DCD ;.

This mismatch is memorized by fixing unit 7. The voltage value Ar filled at the time of the analog-discrete converter is fed to the input of converter 8. At the output of converter 8, a code La is obtained, corresponding to value A2. This code is written to the second memory location through the switch. Then the second reading is completed.

The values of AB A2, ..., At are the leading coefficients of the parabola. They are sequentially stored in memory block 10. The gain factor K. in block 6 is set on the basis of the stability conditions, which allows to achieve convergence of the parabolic approximation to the function of the input signal (see Fig. 2)

1 dait + -f а, „

where Ug is the approximate parabola on

i-M sampling area; azg - the highest coefficient of the parabola on the i-M segment of discretization,

then when / Gdvskr

 - о.с - (argtdiskr + a, rhd

disc G

+ Sv /) - (21 / disk + yvd) "ag disk

t / vzh - i /

.

.c gd 65 (l-A-) A; d. Yes .L.2, -n2 K - coefficient of proportional reduction.

Stability studies have shown that for the stability of the convergence process of the approximating function to the input signal function, the coefficient K. should

to be smaller units the best convergence conditions for

When the device is operated, the leading coefficient of the parabola is recorded in the cell whose number corresponds to the number of the section of approximation; the lower coefficients are restored automatically upon transition from one section of approximation to another. The operation of the device ends when the entire memory is full. Some implementations are recorded in the memory.

Claims (2)

1. Analog-discrete functional device containing a control unit, a subtraction unit, the first input of which is connected to the input signal bus, and the second input - to the control unit, an analog-to-digital converter, the control input of which is connected to the control unit, and the output to the input of the switch, the second input of which is connected to the control unit, characterized in that, in order to expand the functionality and redundancy of counts, a memory block, a fixation block, an additional switch, a code-to-voltage converter, and a function converter, which control the inputs of which are connected to the control unit, the output of the subtractor through the fixing unit connected to the input of the analog-digital converter, the output of the switch through the memory unit, an additional switch, the code to voltage converter and the functional converter connected to the third input of the subtractor. 2. The device according to claim 1, characterized by that the functional converter consists of two consistently connected integrators. Sources of information taken into account in the examination 1 USSR Author's Certificate No. 196442, cl. H OZK 13/02, 1965. . g