SU781866A1 - Shaft angular position-to-code converter - Google Patents

Description

(54) ANGLE CONVERTER TURNED TO CODE

The invention relates to systems for automatically converting movements into a code, namely, converters of shaft angle into code. A shaft angle converter is known for a code comprising a sine-cosine rotational transformer (SCWT) and a code signal generating unit made in the form of a multiphase transformer, To the windings of which phase-sensitive elements are connected with trigger output .j, the disadvantage of this device is its relatively low accuracy. The closest technical solution to the present invention is a shaft rotation angle converter. In a code, the M-bit codeDanine sine-cosine transformation into voltage (SKPN) series, connected, for example, in the form of a pulse generator, a former of a symmetric triangular function and two chains of series-connected comparison unit, a phase inverter and a power amplifier, a SCRT, a selective phase-sensitive rectifier and a unit for generating a useful signal, made after ovally connected — reversible counter and voltage-to-frequency conversion unit; and the outputs of the reversible counter are connected to the digital inputs of the N-bit sine-sinus transform code to voltage [2]. A disadvantage of the known device is the low conversion accuracy due to instability of amplitude and phase characteristics. m61cnbsti amplifiers7 The purpose of the invention is to improve the accuracy of the device by eliminating the influence of the errors of the power amplifiers on the accuracy of the conversion. The goal is achieved by introducing a low frequency generator, two keys and a digital adder into the shaft angle converter, the low frequency generator output is connected to the first input of the digital adder and to the control inputs of the keys, the signal inputs of which are connected to the rotor quadrature windings , the outputs of the keys are connected to the inputs of the phase-sensitive rectifier, the second and third inputs of the digital adder are connected to (Nl) -HM and to the N-th outputs of the reversible counter, the outputs of the digital adder are connected (N-l) -HM and N-th input N-discharge unit SKPKN.

The drawing shows a structural Hema Converter angle of rotation of ala in the code.

The converter contains N-bit block 1 SKPN, SCWT, phase-sensing rectifier 3, reversible counter 4, block 5 converting voltage into frequency, power amplifiers b and 7, switches 8 and 9, cis adder 10, low frequency generator 11.

From the first through (N-2), the discharge outputs of the reversible counter 4 are connected 1k corresponding to the first to {N-2) discharge inputs of unit 1, the outputs of which through the amplifiers S and 7 of the power are connected to the sinus and cosine windings of SKVT 2 located on a stator, the rotor windings of which through the keys 8 and 9 are connected to the input of the phase-sensitive rectifier 3. The output of the phase-sensitive rectifier is connected to the input of the voltage-to-frequency unit 5.

The outputs of the generator 11 are connected to the second inputs of the corresponding switches B and 9, and one of the outputs of the generator 11 is connected to the lower bit of the second input of the digital adder 10, the first and second bits of the first input of the adder 10 are connected respectively to (N-1) and M-bit The meter has a single meter 4, and the bit outputs of the adder 10 are connected to the (N-1) and N-bit inputs of the SKPKN block 1, respectively.

Converter angle of rotation of the shaft in the code works as follows.

At the output of the generator 11, a square signal of the square wave type is formed, which is fed to the control inputs of keys 8 and 9, as well as to the low-order input of the second input of the digital adder 10. The rectangular signal at the output of the generator 11 has two levels: zero and one. The design of the keys 8 and 9 is chosen so that when the control voltage is zero, the control inputs of the keys 8 and 9 are applied to the control, one key switch, for example the key 8, is in the open position and the other key 9 is in the closed position. With a single level of control, the voltage of the key 8 is in the closed positions and the key 9 is in the open position.

The design of the digital adder 10 is selected in such a way that at zero the output voltage level of the generator 11, the N- and (m-1) bits of the reversible counter 4 passes through the two-digit adder 10 without changing, while the M-digit the code or the input of the unit 1 SKPKN is equal to the N-bit code of the reversible counter 4. When | at the Main level of the output voltage of the generator 11 in the digital JO accumulator

781866

from the code N and (N-1) bits of the reversible counter 4, the unit of the lower bit is subtracted, corresponding to the unit code (N-1) of the discharge of the reverse counter 4. In this case, the N-bit code on the input of the SKPN block 1 is different than pt N -discharge code of the reversible counter 4 by an amount equal to.

In accordance with the numerical equivalent-. An 11-fold ribbon of a random code arriving at the digital input of unit 1 SKPKN, periodic signals are generated at its sine and cosine outputs, with amplitudes of the first harmonics

2

5 and

S i p (q.- -jc-) s i n (w t);

and

G wm °

cos ((- -) sin (Wfjt),

UK

2

Qm °

I2 - the amplitudes of the output signal and the crop on the sine and cosine outputs of the SKPKN unit

 the numerical equivalent of the full N-bit code Qm 2;

q is the current value of the N-bit code entering the digital input of the SKPN module;

VIQ - repetition frequency of peri-, tonic signals on

 the outputs of the SKPN block

WQ W c.

The amplitudes of these signals 1) and U2, taking into account the amplitude errors of amplifiers 6 and 7 of power s, are generally unequal to each other. These signals are sent to the recording of the sinus and cosine windings of SCPT 2 and induced in the rotor windings of SCPT 2, the EMF values of which, when the generator is disconnected from the cn-low frequency, are determined from the ratios

1 o / U Uo-Kn-s n (ao-4o i: S 2 o sincoot-,

/ D) l.

Upa - Uo-KnC03foCo- | -K -A4r-S n2o6Js na) oti

 4ff |

DF5: yFosn A with "tue about

where l is the main conversion error due to the inequality of the amplitudes of the signals and. (and Uo;

MocN-Tf (Atfgj. Is an additional conversion error due to the technological errors of the SCRT — the amplitude and angular non-orthogonality of the stator windings of the SCRT.

When the low-frequency generator 11 is turned on for the first half period equal to j TI - the rectangular voltage has a zero level, and the output q code of the reversible counter shown above passes without change through the adder 10, m. q q, and the input of the phase-sensitive rectifier 3 through the key 8 receives a signal from the output of the rotor winding of the SCRT. When O g. + Atf, S n2tfo) s4nOo. During the second half-period - T, the rectangular voltage of the generator AND takes a single level, while the output koA of the reversible counter in the adder 10 is changed by units, i.e. qq -, and to the input of the positive-sensitive rectifier 3 through switch 9, a signal is output from the output of the sinus winding of SCTT 2, defined by the equation Up5, UQKnS4h oto-4l5 fL2 2 oso By periodically switching signals from the rotor windings of SCWT and by periodically changing the output code of the reversible counter 4 by an amount equal to a periodic signal amplitude m the error of the angular error is equal to w. The total signal at the input of the selective phase-sensitive rectifier is l ol n s K-4Q -))) c cdc) j.) Ot (2 к и) сОКН. Since combinational harmonics with a frequency (WQ + (2K-l)) that determine the total error & (fj npeo6producer at WQ W) differ in frequency from the main useful signal, these harmonics in the phase-sensing rectifier 3 are filtered from the useful signal as an interference and do not affect the output control signal generated at the phazg output of the sensitive rectifier. The mismatch output signal of the voltage-sensing rectifier 3 is about 5 ("o -qfj is fed to the input of the voltage conversion unit 5 to the frequency in which the output code q and the reversing counter 4 are changed by until the error signal equals zero. At Ugj, O the numeric equivalent of the qN-bit output code of counter 4 is equal to the measured angle of the amplifiers, 7 urnsti, and also some errors of the SURF 2 are not affected on measurement accuracy. In principle, the converter converts the angle of rotation of the shaft into a code to improve the accuracy of converting the measured angle into a digital code by eliminating the influence of the amplitude errors of the power amplifiers. The economic effect of using the converter of the angle of rotation of the shaft into the code is due to its technical advantages noted above. of the invention The converter of the angle of rotation of the shaft into a code containing an N-bit block of sine-cosine conversion of a code into a voltage, the outputs of which are connected via power amplifiers to the sine and cosine windings of the sine-cosine vrav: 5anzhegos transformer, reversible counter, control of which input through bl6k, transforming the voltage into frequency is connected to the output of phase-sensitive mitres metel, (N-2) output of the reversible counter connected to (N-2) a) N-bit inputs of a sine-cosine code-to-voltage conversion, characterized in that, in order to improve the accuracy of the converter, a low-frequency generator, two keys and a digital adder, a low-frequency generator output You are connected to the first input of the digital adder and to the control inputs of the keys, the signal inputs of which are connected to the rotor quadrature windings of the sine-rotary rotating transformer, the outputs of the keys are connected to the inputs of the phase-sensitive rectifier, the second and third inputs of the digital adder are connected to (N -1) and with the N-th output of the reversible counter, the outputs of the digital adder are connected to (M-1) -Y-th and to the N-th inputs of the N-bit block of the sine-cosine code-to-voltage conversion. Sources of information taken into account during the examination 1. D. Shvarnik remote transmission, 1974, p. 193-196. 2. Authors certificate of the USSR .496581, cl. G 08 C 9/04, 1967 (prototype).

Claims (1)

Claim The converter of the angle of rotation of the wa20 la to a code containing an N-row block of sine-cosine conversion of the code into voltage, the outputs of which through power amplifiers are connected to the sine and cosine windings of the sine-cosine rotating transformer, a reversible counter, the control input of which is through the voltage conversion unit in frequency is connected to the output of the phase-sensitive rectifier, (N-2) outputs of the reversible counter are connected to (N-2) inputs of the N-bit block of the sine-cosine code to voltage conversion, characterized in that, in order to increase the accuracy of the converter, a low-frequency generator, two keys and a digital adder are introduced into it, the output of the low-frequency generator is connected to the first input of the digital adder and to the control inputs of the keys, the signal inputs of which are connected to the quadrature rotary windings of a sine-braid rotary transformer, the outputs of the keys are connected to the inputs of a phase-sensitive rectifier, the second and third inputs of the digital adder are connected to (NI) -hm and to the N-th outputs of the reversible counter, moves digital adder connected to the (N-I) -N-hm and with N-input N-th block raeryadnogo sine-cosine conversion code into a voltage.