SU720455A1 - Shaft angular position-to-code converter - Google Patents

Description

I

The present invention relates to the field of automation and computer technology and can be used in information and measurement systems and in processing systems (} of law to convert the rotor angle of electric micromachines, such as sinus-sinus-rotating rotary transformers (SCWT), into a digital code.

A device is known which includes a voltage-code converter, the output of which is connected to the output terminal of the device through a code converter, a sine-cosine rotating transformer, the excitation winding of which is connected to the output of the power supply unit, and the sine and cosine switch (char through the down switch - to the input of the converter voltage-od, and the octant selector, the inputs of which are connected to the output (sinus and cosine) windings of the SCRT and the output of the power supply unit, and the outputs to the control input of two switch position switch2

Chat to a code converter directly and through a block of constants, multiples of 45 ° C.

This device has a low linearity of the conversion characteristic due to the presence of a significant methodological error in approximating a sinusoid by a straight line segment at its initial 45-degree portion adjacent to the angular axis.

The closest to the proposed converter is an angle-code converter containing a SSCT, the excitation winding of which is connected to a power supply source, and the output (sine and cosine) windings through voltage converters, a switch and a code-to-code converter to an output terminal device, the quadrant determination unit of the angle of rotation, the inputs of which are connected to a power supply voltage source and output (sinus and cosine) windings of a SCRT, and a logic unit whose inputs are connected to the outputs of the block definiteness quadrant rotation angle and the switch, and the outputs - to the inputs to gfeobrazovatel aa E code directly and through block constants sratnyh 45.

The disadvantage of this converter is the low linearity of the conversion characteristic, due to the presence of significant methodological error in the approximation of a sinusoid by a straight line segment in its initial 45-degree segment adjacent to the angular axis.

The aim of the invention is to improve the accuracy of the converter, which is achieved by increasing the linearity of the conversion characteristics. To do this, keys, comparators, summing and subtracting blocks, output windings of a sine-cosine rotary transformer of the first half of the transducer directly to the inputs of the first commuter, summing and subtracting blocks to the first inputs of the first to the second key, which outputs are interleaved, are entered into the device. and connected to the first input of the second comparator and the third key, the outputs of the summing and subtracting blocks are connected to the primary inputs of the fourth and fifth keys, respectively, whose E.OUTS are combined and connected to the second input of the second comparator and the first input of the sixth key, outputs The third and sixth keys are combined and: H are connected to the input of the Kapra converter in the same code; the second and third outputs of the quadrant of rotation angle are connected to the second inputs of the fourth and fifth keys, respectively, the first and the second swarm vyh.od5 first comparator; they are connected to the second and third in the co- logical unit and the second inputs of the first to the second key, respectively, the first and second outputs of the second comparator are connected to the fourth and fifth inputs of the logic unit and the second inputs of the sixth and third key, respectively.

FIG. 1 shows the flow diagrams of the converter; in fig. Figure 2 shows the graph, which explains the principle of the formation of additional stresses, the change in the sign of the phase of which occurs at the points of the vertical axis, corresponding to the angles + a-90 °. . Where ". -O, 1, 2, 3.

The device contains a converter 1 voltage-code, the output of which through a converter 2 code into a code is connected

with the output terminal of the device, SCWT 3, the excitation winding of which is connected to the source 4 of the supply voltage, sine and cosine of the windings to the inputs of the comparator 5 directly, and through the keys 6 and 7, the outputs of which are combined, to one of the inputs of the comparator 8 and directly to the input of the voltage converter in the code through the key 9,

Summing up 10 and reading 11 blocks, the inputs of which are connected to the output sinus to the streamers “The 1st windings of SCRT, and the outputs through the keys 12 and 13. The outputs of which are combined, - to the other input

the comparator 8 directly and to the input of the transducer of the short circuit through the key 14, block 15 Ofadchlenk} of the angle of rotation of the wedding, the inputs of which are connected to the output {sinus and cosine

The SCT windings and the source 4 are supplied with power, and the outputs to the control inputs of the keys 12 to 13, as well as to one of the inputs of the aogkpese unit 16, the other inputs are cohort; Comm; Shepy with zyhoda.

the mi comparators — l; warate into the codes of the keys B, 7. 9 and 14, and the outputs with the inputs of the converter kotz in k

all over and through the block of 17 constants

 about

22.5. The composition of the converter

2 codes in the code includes a code transmission block 18 and a circuit 19. complex codes.

How. on the spot, the voltage U and U of the output, (the sine and cosine} windings of the SC. PT 3 are determined as follows:

zok ::

and, li and bin sh t sin; both K and fti h (.t) t soy e;

(one)

gyayi.si

the ampere value is the circular frequency of the voltage U of a ptggapi block 4j and the angle of rotation poTOf of SCWT;

q to transformation coefficient, for the time being .pl of this type of SCRT,

According to the 1-) voltage comparison results, the comparator 5 selects

(one

the smaller of them (we denote it conditionally; by): if IU.jl U., f, the signal from the trans. The output of the comparator 5 is supplied to the control input of the key 6; it sets it to the closed position, at which the voltage J of the sinus motor clock SCWT is supplied to one of the inputs of the comparator 8; if a . UJ, the signal from the second output of the comparator 5 g:; ..: stupidly controls the input of the key 7 and sets it to the same position, at which to the same input of the comparator 8 (since the outputs of the keys bn 7 are combined) the voltage Uj of the cosine winding of the SCWT is applied. The change in the sign of the phase n of the ratio of the amplitudes of the stresses U and Uj occurs at points of the angular axis, which divide the entire range of changes in the angle of rotation Q into 8 sectors (octants) of 45 ° each. Depending on the sector number, it would be possible to select and convert to a digital code the lesser of these voltages, i.e., but the accuracy of the digital measurement of the angle of rotation would have turned out to be a small significant increase in the second half of the CRTOpe (22.5 - 45) shares, errors from nonlinearity of sinusoidal characteristic angle - “apr. On the other hand, the smaller the initial sector, the more accurately the initial portion of the sinusoid adjacent to the angle of the left axis can be considered a straight line segment. This is the basis of the construction of the proposed device, increasing the linearity of the conversion characteristic of which is associated with the formation of additional stresses, changing the sign of the phase and origin of it at the points of the angular axis corresponding to the angles; , p p 1 - p, where p is O, 1, 2, 3. Condition (2) is satisfied by the stresses obtained by performing the operations of algebraic addition and scaling of the output signals of the SCRT in addition blocks 10 and subtracting 11: 3 ) .Shtsmt45-e); H (-) 3) where t is a constant scale factor. Changing the sign of the phase and the ratio of the amplitudes of the original and additional ones. The stresses (Fig. 2) now occur at points of the angular axis, which divide the entire measurement range of the angle, Q, into 16 sectors of 22.5 each, and in each sector you can select a voltage (initial or additional) that varies almost linearly The limits of the initial part (O22.5 of the sinusoid adjacent to the angular axis (in Fig. 2) are marked with a solid line). 55 Plot 22.5 45 ° is thus excluded from consideration. The selection of the specified voltage, which is subsequently used for the purpose of converting to a digital circuit, is carried out as follows. The angle of rotation quadrant determination unit 15, based on the results of the analysis of the sign of the phase of the output voltage of the CCTVT relative to the voltage Ufi of the power supply of block 4, generates a signal of the angle of rotation quadrant 0. In i-OM and 3-evi quadrants, this signal goes to control key 13 and sets it to a closed position, connected to another code 8, voltage 1; u U from the output of block 11E chigani, and in quadrants to control key key 12, pr :. In this case, the oscillator is installed in the gamned position and the input of the equipments S (t, c. the outputs of the keys 12 and 13 are connected) is connected to the output / from the output of the adder unit 10. According to the results of the comparison, for example, Hsn; Ud and UH l;: Between itself, the comparator 8 chooses MeKiujee from kkh:, 1 11 | m1, schngag; from the first comparator 8 it enters the corner (equal to the input of the key J. 4) it enters into a third marriage, during which the bridom Od moves on to the entrance of the op-amp S-KO (PIC); tlJwJiiU i , signal from BiOporo z; move xsiarag-ore 8 enterance FU, releasing the input 9 to set it in a closed position, at which the input UN transducer to the PNK input is converted to a digital equivalent on its input voltage. The number (sign) of that mon of another of the 16 22.5 degrees, the sectors is determined by the results the phase relations between the voltages to U; -; (the signal from the output of block 15) and the amplitude relations between the voltages U;, U2, Ui,, and DM (the signal from the outputs of the comparators 5 and 8) of the logical block are available. com 16, quenching the constant block 17, multiples of 22.5, to the position in which the code N,, x) and the voltage U, liriH U, selected with the aid of 10 b, and active are connected to one of the inputs of the adding circuit 19 of block 2 on one of the inputs of the comparator 8, connected to the common tpchks. Ktyuchoy 12 and 13, constant for this sector and corresponding to its left border. As can be seen from FIG. 2, in odd 22.3-degree sectors, where the magnitude of the coded voltage increases with increasing the angle of rotation, the values of the digital code fJj with some degree of approximation reflect the desired angle of rotation 8. In even 22.5-degree sectors, where with an increase in the rotation angle of 0, the amplitude k6 of the voltage being dieted decreases; The zilinear relationship between the digital code N and the angle of rotation 9 is broken: an increase in 8 corresponds to yy.e. Ny. In order to eliminate the ambiguity that has occurred, in the even 22.5 degree sectors it is enough to invert the N code. For this output

for example, by reading the encoding result from the inverse (zero) bit outputs; Triggers of the final register of the NCP 1. In odd 22.5. coarse sectors, block 18 transmits code S from the output of OCP 1 to another input of circuit 19 without change, 19 add code from real code; t add the operation of Mp to Nj codes (fJi). with: gabr "zhayuschkg with the help of

D- sector and the rotation angle 0 of the rotor of the SCVT P ego№ sector.

For K5g: 1Steam14 hr lokvni zs the successiveness of the considered operations is summarized in the table below. logical block 16, a special feature P (high potential) is formed, in accordance with which block 18 of the transmission of the code triggers the inverse operation W {of the code M applied to its input,

Thus, in the proposed device, an increase in the linearity of the conversion characteristic is achieved.

Claims (2)

the expense of coding a voltage selected from among the initial and additional ultrasonic, U4 voltages according to the results of comparing them with amshtuts, at the initial 22.5-degree portion of the sinusoid, with a leaning to the angular axis. Compared to the prototype, where the change in the result code corresponds to a change in the coded voltage on the 45-degree portion of the sinusoid adjacent to the angular axis, the error from the nonlinearity of the conversion characteristic decreases by about 1.7 times. Claims of the shaft angle converter into a code containing the converter, for example, a code whose output is connected to the first input of the code converter to the code, a sine-cosine rotating transformer, the excitation winding of which is connected to the power supply source, the output windings to the first and the second input of the angle quadrant determination unit, the third input of which is connected to the source-voltage, the first output to the first input of the logical unit, the first output of which is connected to the second CS the input of the code converter into the code, the second output through the block of constants to the third input of the code converter into the code, I distinguish that in order to improve the accuracy of the converter, 1sh are entered into it; eyes, comparators, summing and subtracting blocks, output windings are skanusno - a cosine-rotating rotating transform 7,310 of a sormagor is connected to the inputs of the first comparator, summing and subtracting blocks and to the first inputs of the first and second key, the outputs of which are combined and connected to the first inputs of the second comparator and the third key, outputs The umming and subtracting blocks are connected to the first inputs of the fourth and fifth keys, respectively, whose inputs are connected to the second input of the second comparator and the first input of the sixth switch, the outputs of the third and sixth switch are connected to the input of the voltage converter in the code, the second and the third outputs of the quadrant definition of the angle of rotation are connected to the second inputs of the fourth and fifth keys, respectively, the first and second outputs of the first comparator are connected to the second and third inputs of logic of the first block and the second key, respectively, the first and second outputs. the second comparator is connected to the fourth and fifth inputs of the logic unit and the second inputs of the sixth and third keys, respectively. Sources of information taken into account in the examination 1. USSR author's certificate number 59100 cl. G 08 C 9/04 of 21.05.76. 2. USSR Author's Certificate K% 332488, cl. G 08 C 19/28 OT.O4.O5.7O (prototype).