SU1248069A2 - Shaft-to-digital converter - Google Patents

Abstract

The invention relates to automation and measurement technology, can be used to measure the movements of the working parts of machine tools and is an improvement of the invention according to the authors. St. No. 1030824. The aim of the invention is to increase the accuracy of the converter by reducing random errors. For this purpose, a converter containing a sine-cosine sensor, a bandpass amplifier, a phase-sensitive pulse shaper, reversible counters, a pulse generator, a frequency divider, a pulse-width modulator, the first delay element, a trigger, a decoder, and And elements and OR elements, Two D-triggers, an additional delay element, a buffer register, and a logic unit bus are introduced. The accuracy is increased due to the fact that in the converter a pulse arriving at the C input of the first D-flip-flop with the help of the second D-flip-flop and an additional delay element ensures synchronization of the beginning of the formation of information about the movement of the sine-sinus transducer. 2 Il. i (Л N5 i4 00 О а; о к

Description

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The invention relates to automation and measurement technology, can be used to measure the movements of the working bodies of metal-cutting machines and is an improvement of the device according to the main author. No. 1030824.

The aim of the invention is to improve the accuracy of the converter by reducing random errors.

FIG. 1 is a block diagram of a displacement transducer to a code / FIG. 2, a time diagram explaining its operation.

The converter contains a sine-cosine sensor 1, .band amplifier 2, a phase-sensitive shaper of 3 pulses, reversible counters 4 and 5, a generator of 6 pulses, a divider 7 frequency, a pulse-width modulator 8, a delay element 9, a reversible counter 10, a trigger 11, reversible counter 12, decoder 13, elements AND 14, 15, elements OR 16, 17, D-flip-flops 18 and 19, additional delay element 20, buffer register 21.

The motion to code converter operates as follows.

The reversible counter 4 stores a number proportional to the current position of the movable part of the sine-cosine sensor 1. The width of the voltage pulses produced by the pulse-width modulator 8 and fed to the input sine and cosine windings of the sensor 1 is determined by the number written in the reversible counter 4. Changing this number causes a change in the width of the sine and cosine signals of the sensor 1. In a statistically consistent position, these signals are such that at the output of sensor 1, the voltage is close to zero. In this case, the trigger 11 is in the single state, and the reversible counters 10 and 12 are in the zero state.

When moving the moving part. Sensor 1 produces an error signal at its output. The bandpass amplifier 2 amplifies the error signal and extracts the first harmonic of this signal. The amplified mismatch signal is fed to the input of a phase-sensitive driver 3 pulses. The signal coming from one output element 9 delay.

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shifted by 1/4 of the period T from its start and falls to the maximum of the error signal. If the magnitude of the error is greater than the threshold of a three-pulse phase-sensitive generator, 3 pulses are output at one of the outputs (depending on the phase of the error). Thus, with positive movement of the movable part of sensor 1, a positive mismatch occurs and the phase-sensitive driver 3 pulses emit pulses that flow through the element OR 1 7 to the reversible counter 4, increasing the number stored in it. In addition, these pulses are fed to the summing counting input of the reversible counter 10, increasing the number stored in it. By

The signal from the other output of delay element 9 (which is shifted by 1/2 T from the beginning of the period) is overwritten by the number from the higher bits of the reversible counter 10 to the reversible counter 12. If this number is not zero, the decoder 13 produces a single signal, permitting the passage of pulses from a generator of 6 pulses through elements 14

30 and 15 With a single state of the trigger 11. The pulses from the output of the element And 15 flow through the element OR 17 to the summing counting inputs of the reversible counters 4 and 5. At the same time

,, pulses from the output of the element 15 are fed to the input of the subtractor of the reversible counter 12. When the number in the reverse counter 12 becomes zero, the decoder 13 will prohibit the passage

4Q pulses through AND elements 14 and 15. If the number of pulses arriving each period corresponds to the amount of movement of sensor 1 over a period, then at the output of sensor 1, the matching signal will be zero. When the positive speed of movement of sensor 1 decreases or when negative movement occurs, a negative mismatch occurs. The phase shifter 3 generates pulses, which are fed to the input of the subtraction of the reversible counter 10a through the element OR 16 to the subtraction inputs of the reversible counters 4 and 5.

55 When the state of the high-order bits of the reversible counter 10 becomes zero, and the state of the reversible counter 4 corresponds to the field

sensor 1, the error signal at the output of sensor 1 will be zero.

If the sensor moves 1 negatively, the overflow pulse of the reversing counter 10 sets trigger 11 to O.

The signal from the output of the holding element 9 from the reversible counter 10 is entered into the reversible counter 12, the decoder 13 gives permission for the generator 6 to pass through the AND 14 element, which through the OR 16 element is fed to the subtraction inputs of the reversible counters 4, 5 and to the summing input reversible counter 12.

When the state of the reversible counter 12 becomes zero, the decoder 13 will prohibit the passage of pulses through the elements 14 and 15. Thus, in the upper bits of the reversible counter 10, a number corresponding to the speed of movement of the sensor 1 will be recorded, and in the reverse counter 5 in each period T will be recorded a number corresponding to the current position of the sensor 1.

When a positive edge of the polling input pulse appears from the CNC at the synchronization input of the D-flip-flop 18, it is set to state 1. The output signal from the D-flip-flop 18 is fed to the input D of the D-flip-flop 19 and ensures that it is set to the next positive edge of the generator 6 pulses. This ensures that the input polling pulse and the synchronization with the internal 6 pulses of the converter are memorized. After some time, determined by the delay element 20, the signal from its output overwrites the movement information from the reversible counter 5 to the buffer register 21. Then, the signal from the output of the delay element 20 records the zero to the reversible counter 5, resets D- flip-flop 18 and simultaneously write zero to frequency divider 7. After sbro480694

A D-flip-flop 18 on the next-positive edge of the signal from the 6-pulse generator operation of the converter will continue from the beginning of the first 5 internal clock of the converter (Fig. 2). Reading information from the buffer register 21 (output) can be performed at any time between two successive polling pulses.

U, Thus, in the reverse counter 5, information on the movement of the sine-cosine sensor a 1 is accumulated and transferred to the buffer register 21 during the time interval of the remote control by two successive polling pulses from the CNC.

Thus, synchronization of the movement of the displacement transducer into the code with the system

20 CNC, which leads to a decrease in random error.

Claims (1)

Invention Formula 25 Motion converter to autolt code No. 1030824, which is based on the fact that, in order to increase the accuracy of the converter by reducing random errors, a buffer register, an additional delay element, the first and second D-triggers, and a bus of the logical unit, the first output of the additional the delay element is connected to the set zero inputs of the second reversible counter, the first D-flip-flop and the frequency divider, the D-input of the first D-flip-flop is connected to the bus of the logic unit, the CQ input is the polling input of the converter, and the output is connected to the D-BXO- house of the second D-tr ggera whose output is connected to the input of the additional delay element j You are a second stroke which is connected to the buffer register write input of the pulse generator output is connected to the C-input of the second D-flip-flop data inputs of the buffer register connected to the outputs of the second reversing schet0 chica. 5khod Out