SU1658208A1 - Device for stabilization of speed of movement of magnetic recording medium - Google Patents

Abstract

The invention relates to instrumentation, namely, devices for controlling the speed of movement of a magnetic recording medium, and allows the device to expand its functionality by making it possible to change the law of regulation. In the first memory block 10, the current as well as certain previous values of the phase error of the magnetic carrier are recorded. In the second memory block 11, control action codes are entered. These codes, as well as the codes from the outputs of the cells of the first memory block 10, are fed to the address field of the third memory block 12. The values of these codes determine a certain cell in the third block of paragraph 12, in which the control action code calculated in advance with a given law. 3 il. Ј (L

Description

The invention relates to instrumentation, namely, devices for controlling the speed of movement of a magnetic recording medium, and can be used in precision electric drives of precise magnetic recording apparatus.

The purpose of the invention is to expand the functionality of the device by providing the possibility of changing the law of regulation.

FIG. 1 shows a block diagram of the proposed device; in fig. 2 - time diagrams that show his work; in fig. 3 shows an example of the execution of memory blocks and a digital-analog converter.

The device contains serially connected digital-to-analog converter 1, power amplifier 2,

electric motor 3, magnetic carrier 4 and speed sensor 5, kinematically connected with electric motor 3, master oscillator 6, the output of which is connected to the input of frequency divider and synchronization unit 7, phase discriminator 8, the first input of the second one connected to first-output unit of frequency divider 7 the second input is with speed sensor 5, and the output is with the first input of time converter 9, the second input of which is connected to the second output of the block / frequency divider, and the output to the second input of the first memory 10, the first input of which is connected with tr Another output of the frequency divider unit 7, with the first input of the second memory block 11 and with the first input of the third memory block 12. In addition, the third input of the third memory block 1

about

SP

00 N3

About 00

It is connected with the output of the second memory unit 11, and the output is connected with the input of the digital-analog converter 1. Magnetic medium 4 is understood as either a video head disk or a package of magnetic disks. In the first case, the video heads must be strictly followed by the investigator along the lines of the video signal recorded on a magnetic tape. This is achieved by synchronizing the position and speed of the head disk relative to the reference signal generated by the master oscillator 6. Such a synchronization is carried out by the proposed device. A package of magnetic disks is synchronized in the same way.

The device works as follows.

The inputs of the phase discriminator 8 receive signals from the speed sensor 5 U (see Fig. 2) and the frequency divider and synchronization unit 7 from U. At the output of the phase discriminator 8, a pulse width signal Uj is generated that is proportional to the phase error. This signal is filled with a high frequency from the output of block 7. Transducer 9 time –code counts the number of pulses in the received packs U. At the end of the counting, the output of transducer 9 contains a code proportional to the phase error. The correction device, in which the first 10, second 11 and third 12 blocks of memory are included, converts this code in accordance with the formula

And | tl

Ohno

-3KH i-k + Ј-ug

bnY; g,

(one)

four

four

where Y is the code at the output of the correction device at the i-th instant of error measurement X ;;

 - constant coefficients.

For example, a discrete PID controller is described by the following equation

neither eat:

Y; aox; + a; x; - + agx; -g

where X j and X are the error values

in (i-D-th and (1-2) -th time points, respectively;

Yj (is the code value at the output of the correction device in the previous measurement cycle. The code from the output of the converter 9, corresponding to the i-th measurement, is recorded in the first cell of the first block

five

0

five

0

five

0

five

0

five

0

10 memory by the signal U from block 7. At the same time, the code from the first cell of the first memory block 10 is copied to the second, from the second to the third, from (n-1) -th to n-th. Thus, the recording of information in the first memory block 10 is performed according to the stack principle.

I

Similarly, the codes are moved in the second memory block 11. In this block, codes from the output of the third memory block 12 are recorded. Thus, in the first memory block 10, codes corresponding to the phase error from the i-th no (in) -e measurement, and in the second memory block 11, codes corresponding to the control action of Y from (i-1) -ro no (im) -fi point in time. Accordingly, the first memory block 10 should consist of (n + 1) -th memory cell, and the second memory block 11 should consist of a heap of memory cells. The third block of memory 12 must contain code values corresponding to the Y values calculated by formula (1). The contents of the memory cells of the first 10 and second 11 memory blocks are fed to the address input of the third memory block 12. The address value indicates a cell in which a code is preliminarily written, calculated by formula (7) with previously known ak and le and possible ones. By the signal Ub, the contents of this cell are fed to the output of the third memory block 12, and therefore to the input of the digital-analog converter 1.

Claims (1)

Invention Formula A device for stabilizing the speed of movement of a magnetic recording medium containing an electric motor with kinematically coupled magnetic media and a speed sensor, a master oscillator, the output of which is connected to the input of the frequency divider and synchronization unit, a phase discriminator, one input of which is combined with the first output of the frequency divider and synchronization unit, and the other with a speed sensor, a time converter, a code, one input of which is connected to the output of the phase discriminator, and the other to the second output of the splitter unit often s and synchronizing, power amplifier, the output of which is coupled with an electric motor, characterized in that, in order to expand the functionality of the device by providing the possibility of changing the regulation law, the first, second and third memory blocks, as well as a digital-to-analog converter, are inserted in it, the first inputs of all three memory blocks connected to the third output of the block frequency divider and synchronization, the second input of the first memory block is connected to the output of the time-code converter, and the output is connected to the second input of the third memory block, the third input of which is connected to the output of the second memory block, and the output to the second input of the second memory block and input to a digital-to-analog converter, the output of which is connected to the input of a power amplifier. H V, Fig 2 1 "I €