SU963034A1 - Shaft angular position-to-code converter - Google Patents

Description

The invention relates to automation and can be used in digital control systems for the angular positions of drive mechanisms.

The known photoelectric angle converter is your code based on the use of raster matching and intra-step phase interpolation.

A known converter comprising a pulse generator connected via a frequency divider to a phase splitter, the outputs of which are connected to the inputs of a phase raster interpolator (phase shifter) whose output is connected via xOjU

to Comparator t2.

The disadvantage of such a converter is the presence of significant errors introduced by the filter and the eccentricity of the disks of the phase shifter.

A known converter comprising a two-phase sinusoidal voltage carrier voltage generator connected to a phase shifter, the output of which is through an amplifier, a filter and a comparator is connected to an account control unit consisting of triggers, And blocking generator elements, two-phase clock pulse generator and two counters the control unit of the account is connected to the summing and subtracting inputs of the reversible counter. The phase shifter contains a disk with a radial raster grating, a radiation source optically coupled through the constriction of a radial raster grating to reflect its projection by means of a glass fiber light guide with a diametrically opposite part with four receivers.

15 radiation connected to a summing circuit, which feeds a two-phase frequency generator of the SPZ.

The disadvantage of this converter is significant errors introduced by a two-phase sinusoidal voltage generator, an amplifier, a filter and a comparator, as well as the complexity of the account control circuit.

Also known as photoelectric

25 is an angle-to-code converter, in the exact reading of which a phase shifter is included, comprising two conversion channels, each of which is represented by amplifiers, connected

30 sources and receivers of radiation optically coupled through a four-phase raster junction f 4. The disadvantage of the converter is the presence of two analog channels for converting the phase shift into the code, as well as different inaccuracies introduced by these channels. The closest in technical essence to the offer is the shaft angle-to-code converter containing the series-connected pulse generator, the first counter phase shifter, comparator, power amplifiers connected to the phase shifter, the output of which is a filter connected to the null organ, and the output of the pulse generator connected to the first the first element And, the other input of which is connected to the trigger output connected to the subtracting input of the second counter, the second output of the phase shifter is connected to the third additional counter, the high-order direct output of which is connected to the control input of the switch, the third output outputs the counter is connected to the decoder, the first output of which is connected to the installation input of the second counter, and the third output of the decoder and the zero output of the organ are connected to the inputs of the second element And tSj. The drawback of the device is both the design and technological complexity of the phase shifter, as well as the complexity of the electric cxeNttj converter, for example, the use of counters with parallel transfer and reversing recalculation. The purpose of the invention is to simplify the converter. The goal "is achieved by replacing the phase shifter with a photoelectric one with two diametrically anti-idle channels with respect to the axis of rotation of the four-phase raster pairing, as well as the introduction of a second switch, a third amplifier and a third element, And the second switch inputs are connected to the outputs of the phase splitter and the control input of this switch connected to the inverted output of the higher bit of the third counter, the attendants at the input of the second channel of the phase shifter are connected to the outputs of the second switch, the outputs of both channels of the phase shifter are combined. and connected to the filter through the third amplifier, the second output of the decoder is connected to the cTapiueMy input of the second element And whose output is fed to one of the trigger inputs, the third output from the decoder and the output from the zero-organ is fed to the inputs of the third element And whose output is fed to another trigger input. The drawing shows a block diagram of the converter. The proposed converter contains a pulse generator 1, a counter 2, a phase shifter 3, a counter 4, a decoder 5, switches 6 and 7, blocks 8 and 9 amplifiers, a phase shifter 10, a phase shift amplifier 11 on the phase shifter output, filter 12, zero-oprari 13 , elements 14 and 15 AND, trigger 16, element 17 AND and counter. The Converter operates as follows. Pulse generator 1, operating continuously, fills counter 2 with pulses, the highest bit of which goes to phase splitter 3. Outputs 1– IV of phase splitter 3 emit signals, the first harmonic of which is proportional to siniut, cosat, -sinout and –co5Ш1, and the signal from the first output phase splitter 3 simultaneously enters. And the counting input of counter 4,, and the first inputs of switches b and 7. Signals from the same outputs of phase splitter 3 are sent to inputs P -IV of switch b, and not P to j inputs P-jV. the phase splitter 3. To the control inputs V switches 6 and 7 receive control signals from the direct and inverse outputs of the last bit of counter 4. Thanks to this circuit control organization of switches 6 and 7, the signals of the phase shifter 3 alternately turn on (i.e., two clocks) both channels of the phase shifter 10 through blocks 8 and 9 amplifiers. Pass each raster junction, respectively, phase shift signals on both channels are fed to one bus, i.e. processing is carried out on one channel of the analog part of the converter, due to time separation, the amplifier is fed by amplifier 11 and fed to filter 12, in which the first harmonic of the signal, the phase of which is proportional, is ionic to the angle of rotation. At the moment when the output signal of the filter 12 passes through zero when its polarity changes from minus to plus; the zero-body 13 generates a pulse that arrives in parallel at the first inputs of elements 14 and 15 I. At the beginning of the first half of the operation cycle (i.e. at the beginning of the third counter 4) of the converter, the first output of the decoder 5 receives a signal that sets the counter 18 to zero state, and at the end of the first half of the cycle, when the transients caused by switching the power of the phase shifter 10,

from the second output of the decoder 5, sends a signal to the second input of element 14 I, which coincides in phase with the reference (i.e., the first harmonic is proportional to sinurt) by the power signal of the phase shifter 10 and has a duration equal to the period of the signals of the phase shifter 10. In this case, the phase signal with zero - organ 13, having passed through element 14 I, sets trigger 16 to one state, and the output pulses of generator 1 pass through element 17 to the countable summing input of counter 18.

At the end of the second cycle of operation, after the end of the transient processes, the third output of LeshiLpator 5 enters the in-phase with the beginning of the period of the reference signal of the phase shifter 10, to the second input of the element 15 And having a duration equal to the period of the signals of the phase shifter 10.

In this case, the phase signal formed by the diametrically opposite channel of the phase shifter, the amplifier 11, Filter 12 and zero-org 13, as well as element 15 I, return the trigger 16 to the zero state, and the counter 18 stops counting the impulses of the generator 1.

As a result, the code recorded by the counter 18 is proportional to the difference in phase shifts of the phase shifter 10 in the first and second half of the work cycle

Nw / q) ./,

where N is the number of the pulse code of the angle of rotation of the shaft per cycle of the converter; C, is the phase shift on the 1-th channel of the phase shifter; Sj - phase shift on the D-th channel of the phase shifter. In this case, the phase shifts Φ ;, and H are proportional to the angle of rotation of the shaft, i.e.

% “X ();

4 at {-4 + u f),

where If is the angle of rotation of the shaft, counted out in the first channel; if the angle of rotation of the shaft, counted in the iL diametrically opposite channel; d (angular error due to eccentricity of the phase shifter and introduced by the electronic part of the conversion circuit of block 8 and 9 amplifiers, amplifier 11, filter 12, null organ 13. The resulting counter code 18 is proportional to the double angle of rotation of the shaft

,

If there is no shaft sticking during the conversion cycle, the counter 18 remains in the zero state, confirming the immobility of the shaft.

Thus, the push-pull mode of operation for two diametrically opposite to the axis of rotation of the photoelectric phase shifter channel provides both constructive and technological simplification of the phase shifter and the shaft angle-to-code converter as a whole by simplifying the switch circuit (ordinary valve blocks); simplify

Lhema second counter 4 (counter irreversible); eliminating an extra parallel transfer chain together with the valve block of the contents of counter 2 into counter 18, replacing the analog differentiating element with a discrete third element 15 AND; simplify circuit connections between converter elements.

Economic efficiency, from

using the converter will be at least 30-40 thousand rubles. per year with the use of converters in the national economy of the order of a hundred pieces.

It is possible to develop a converter with dimensions smaller by 1.52 times compared with the prototype.

Claims (5)

1. Photoelectric information converters. Ed. Presnuhi-on L.I., M., Mashinostroenie, 1974. p.211-230. 2. Presnuhin L.N. et al. Phase raster interpolator using a filter. In the book. Elements of digital control systems. L., Science, 1971, pp. 1776-182. 3. Presnuhin L.N. and others. Coupling raster position sensors and their application. M., Mechanical Engineering, 1969, pp.161-165. 4. Development of an optical angle-code converter and study of its operation in the behavior of large installations of the P-2500 type. Report on research, stage 1.2 MIREA, 73052737. M., 1979, p.10 and 22. 5. The author's certificate of the USSR 658985, c. 08 C 9/00, 1976 (prototype). it