SU1116446A1 - Shaft turn angle servo encoder - Google Patents

Abstract

CONTINUOUS CONVERTER ANGLE SHAFT CODE containing sine-cosine rotating transformer, the outputs of which are connected to first and second inputs determiner octants analog converter whose output is connected to the first input, whose output is connected to a first input of a phase-sensitive rectifier, the output of which is connected through a low-pass filter with a generator generator, the outputs of which are connected to the corresponding counting inputs of the reversible counter, the power bus connected with a sine-cosine rotating transformer and a second input of a phase-sensitive rectifier, characterized in that, in order to improve the accuracy and speed of the converter, / a switch, two reference signal buses, three comparators, generator, AND-OR element, single-oscillator, inverter are introduced into it , the register of successive approximations, the EXCLUSIVE OR element, the permanent memory of the device, the first output of the switch is connected to the second input of the amplifier, the output of which is connected through the first comparator to the first input of the switch a sequential approximation hysteresis, the output of a phase-sensitive rectifier is connected to the first inputs of the second and third comparators, the second inputs of which are connected respectively to the first and second power buses of the reference signal, and the outputs to the first and second inputs of the I-ШШ element whose voltage is connected through a single-vibrator to the second input of the register of successive approximations, the third input of which is connected to the output of the generator, and the outputs to the third and fourth inputs of the reversible counter, one output of the register of the sequence Approximately connected through the inverter to the third and fourth inputs of the I-SHS element, the outputs of the reversible counter are the outputs of the following converter of the noBojpoTa shaft angle in kbd and .connected to the first group of inputs of the elements 4i 4 This EXCLUSIVE OR, the second group of inputs of which are connected with outputs, determinant of octants,, and outputs are connected through a permanent storage device with digital inputs of a digital-to-analog converter, the first power line is connected to the third input of the determinant of octants, the output of which It is connected to the control input of the switch, the second output of which is connected to the analog input of the digital-to-converter converter, the outputs of the sine-cosine rotary transformer are connected to the first and second inputs of the switch.

Description

1 The invention relates to automation and computing, can be used in digital control systems, measurement technology and robotics to convert fast-variable angular values into a digital angle code and is designed to work with sensors whose output signals are proportional to the sine and cosine of the measured angles, for example, with sine-cosine rotating transformers (CCMW). The known converter of the shaft rotation angle into a code containing SCRT, whose outputs are connected through an octant detector to the first inputs of functional voltage dividers whose outputs are connected to the inputs of the subtraction unit, the output of which is connected through an amplifier and a phase-sensitive rectifier to the corresponding first inputs of the adder and block subtraction, the outputs of which are connected to the inputs of the reversible counter, the output of which is connected to the second inputs of the functional frequency dividers, the generator. The disadvantages of the known transducer with functional voltage dividers are limited accuracy and speed. Closest to the present invention is a follower shaft angle converter into a code comprising a sine-cosine rotating transformer, the outputs of which are connected to the first and second inputs of the octant determiner, the first digital-to-analog converter (DAC), the output of which is connected to the n-first amplifier input, the output of which is connected to the first input of the phase-sensitive solenoid, the output of which is connected through a low-pass filter to a controlled oscillator whose outputs are connected to the corresponding counting inputs and a reversible counter, a power bus connected to a sinus-sinus-rotating rotary transformer, a second input of a phase-sensitive rectifier and a third input of an octant determinant, a sine-sinus-sinus transform code 2. The disadvantages of the known converter are low accuracy, limited by the error of the DAL, and there are part of one of the other devices. , and low speed due to the long transient time, which limits its use for fast conversion of 1xC input impacts. The purpose of the invention is to improve the accuracy of the converter and its speed in transition modes. The goal is achieved by the fact that in the next converter the angle of rotation of the shaft into a stroke contains a sine-cosine rotating transformer, the outputs of which are connected to the first and second inputs of the octant determinant, a digital-analog converter, whose output is connected to the first input of the amplifier, the output of which is connected to the first the input of the phase-sensitive rectifier, the output of which is connected through a low-pass filter to a controlled generator, the outputs of which are connected to the corresponding rectifying counting inputs reversible counter, the first power bus. connected to the sine-cosine rotating transformer, and the second input of the phase-sensitive meter, introduced a switch, two buses of the reference signal, three comparators, a generator, an AND-OR element, a single-shot, an inverter, a serial approximation register, an element EXCLUSIVE OR, persistent storage device, the first output of the switch is connected to the second input of the amplifier, the output of which is connected through the first comparator to the first input of the register of successive approximations, the output of the phase a sensing rectifier is connected to the first inputs of the second and third comparators, the second inputs of which are connected respectively to the first and second power buses of the reference signal, and the output to the first and second inputs of the AND-OR element, the output of which is connected through the single-oscillator to the second input of the sequential approximation register j the third input of which is connected to the generator output, and the outputs to the third and fourth inputs of the reversible counter, one output of the register of successive approximations is connected via an inverter to the third and h The fourth inputs of the AND-OR element, the outputs of the reversible counter are the outputs of the following converter of the angle of rotation of the shaft into a code, and are connected to the first 31 groups of inputs of the EXCLUSIVE OR element, the second group of inputs of which are connected to the outputs of the octant determinant, and the outputs are connected via linear; a memory device with digital inputs of a python-analog converter; the first power bus is connected to the third input of the octant determinant, the output of which is connected to the control input of the switch, the second output of which is It is single with the analog input of the D / A converter; the outputs of the sine-cosine rotary transformer are connected to the first and second inputs of the switch. FIG. 1 shows a diagram of the following converter of the angle of rotation of the shaft into a code; in fig. 2 - switch diagram; in fig. 3 - timing diagrams explaining the operation of the shaft angle-to-code converter; FIG. 4 shows timing diagrams of converter operation in a one-bit conversion mode. The rotation angle of the shaft in the code contains SCVT 1, determinant 2 octants, D / A converter 3, switch 4, amplifier 5, reversible counter 6, phase-sensitive rectifier 7, low-pass filter 8, controlled oscillator 9, mode switch 10, consisting of a register of 11 successive approximations, comparators 12, 13 and 14, a pulse generator 15, a one-shot 16, an inverter 17, an AND-OR 18 element shaper 19 of the tangent-cotangent code, consisting of a permanent storage device (ROM) 20 and the item EXCLUSIVE OR 21. Switch 4 contains t amplifiers 22 and 23, resistors 24-27, elements EXCLUSIVE OR 28-30, inverters 31-34, switches 35-38. The converter of the angle of rotation of the shaft into the code works as follows. Switch 4 (Fig. 2) provides the output voltage of the ACS 1 U and and to the first octant. In this case, the sine input of the converter (the first code of the differential amplifier 5) is energized, the amplitude of which varies from 0 to 0, .7 and in odd octants and from - Os7 and to (in even octants, the cosine input of the converter (first input DAC 3) is supplied voltage .6;: t; e; the amplitude of which is t-MEMALE-; from and to 0.7 and in odd octants and from - and to - 0.7 and in even oKraiites. positive, if it coincides in phase with the reference U sinwt, otherwise the voltage is negative. (J from the output of the SCRT I, to the second input - the inverted voltage tr | from the riser of the amplifier 22. Accordingly, the first input of the switch 36 is supplied with the voltage b, and to the second input - the inverted voltage and The switches 35 and 36 are controlled by paraphase signals from the outputs of the STAKEHOLD or 28 and 29 elements, while the switches 35 and 36 are closed at the control signal and unlocked by the current signal at the control inputs of the Tangent-Cotangent code generator 19 is used Routine Top: The code of the item is EXCLUSIVE OR 2. ROM 20 has a patch that corresponds to the code values of the angle tangent within 0 - l / 4. At the same time, in odd octants, when the third digit of the octant code is O, the address inputs of ROM 20 are supplied with a code from the output of the EXCLUSIVE 1-SHI 21 element, equal to the code of the reversible counter 6 szS, changing from O to J7 / 4, B even octants, when the third bit of the octant code is 1, the address inputs of the ROM 20 are supplied with a code equal to the additional angle code, U 77/4-s-c. The operation of the switch 4, the determinant 2 octants, the former 19 of the tangent-cotangent code is indicated by a tab. All voltages in the table are through the full angles, with the total angles being expressed as follows: CHP-1) pr + (n-) T where, 2,3, ..., 8, is the octant number; 8prl the reduced angle of rotation of the rotor SKVT 1; , the reduced output angle equal to the code at the output of the reversible counter 6. The total angle at the output of the converter is formed by the determinant code

2 octants and a reversible code of 6 equal to the angle,

The error of the error Uj is calculated relative to the reduced voltages, taking into account their reduction. values in the first octant. The D / A converter multiplies the output code of the tangent-cotangent code generator 19 by the voltage at the output of switch 4 (and amplifier 5 determines the difference between the voltage; the output of switch 4U and the resulting product dissipation voltage. The mismatch voltage .lij equal to where is the output code of the former 19. The operation of the switch 4, the reversible counter 6, the former 19 is shown in timing diagrams in Fig. 3. They show the output voltages of the ACS 1 U and (J2 / k 4UJ switchgear and and, the output code of the reversible counter 6 and the tangent-cotangent code generator 19. All voltages are conventionally shown as envelopes, and the AC envelope voltage is considered to be positive if the voltage coincides in phase with the reference voltage and sin tut, otherwise it is considered negative. The change in the code at the output of the reversible counter 6 and the former 19 is shown as absolute values numerically equal to the value of the corresponding code. The mode switching unit 10 is designed to switch the converter from the tracking mode to the incremental weighting mode if the matching signal exceeds a certain level specified by the reference voltages Ug and at the inputs of the comparators 13 and 14. Depending on the signal level a is reversible Counter 6 operates in various modes. With the enabling signal, the bits of the reversible counter 6 repeat the corresponding bits of the register 11, and with the inhibitory signal they change according to the signals of the controlled oscillator 9. This allows you to change the operating mode of the converter when the error voltage U

from the region defined by the reference stresses Ug and and.

Consider the operation of the converter for small changes in the angle 0 of the rotation of the rotor of the SCRT 1, Let the rotor of the SCRT 1 be turned at a small angle b, from the output windings of the SCRT 1 to determine: the 2 octant coil and the switch 4 supply the voltage UU sin.wt sin 9, sinwt cos $. From the output of switchgear a 4, the voltage U goes to the first input of amplifier 5, (J goes to the analog input of the DAC 3, the digital input of which is the code from the driver 19. From the output of the DAC 3, voltage 3 goes to the second input of the amplifier 5, where For example, Ul and U are subtracted and the DC voltage mismatch is equal to) Substitute the corresponding values for Voltage 1: and the code from the table, taking into account the reduction of the total angles to the first 3d. ". t.p (-), we get the error voltage Ij. equal to; S () Uj.U3iMWt COScCfjp for odd octants and) U UstnLot ein () for even: octants. From the output of the amplification of the bodies 5, the error voltage Ug is fed to the input of the phase-sensitive top 7, where it is multiplied. with reference voltage. At the output of the phase-sensitive rectifier 7, the voltage U is obtained. The polarity of which is determined by the lag or the digital value of the Code otnp relative to the rotation angle of the SCET1T rotor 1. The bottom 8 of the frequency. It selects a constant component of voltage 0, simultaneously suppressing the harmonics of the reference voltage and forming the necessary frequency response of the converter as a closed tracking system. From the output of the filter 8, the voltage is higher (Jg is fed to the input of the controlled oscillator 9. The frequency of the controlled oscillator 9 is determined by the magnitude of the error voltage ii and, accordingly, by the magnitude of the voltage Ug, the polarity of which determines the summation or subtraction of the reversing counter 6 the pulses come from the controlled oscillator 9. The output code of the reversible counter 6 goes to the input of the tangent-cotangent code generator 19 and is changed in such a way that the error voltage tends to zero. equal to zero, the oscillations of the controlled generator 9 cease and the output of the reversible counter 6 fixes the code, the digital value of which is equal to the rotation angle of the rotor of the SCRT 1. Consider the operation of the converter when the angle of rotation b of the rotor of the SCRT 1 increases. amplifier 5 has a significant value, respectively, and the voltage U at the output of the phase-sensitive detector 7 is also large, and its polarity is determined by lagging or leading the digital code value relative to la 6j. The operation of the converter in this case is determined by the mode switching unit 10, the nep inputs of the comparators 13 and 14 of which receive the voltage U from the output of the phase-sensitive voltage 7 7 The second inputs of the comparator 13 k 14 are supplied with the voltage U- and comparators 13 and 14, and | U0), and the magnitude of these voltages is selected depending on the time required for the converter to set up in the following mode and the magnitude of allowable changes in the rotation angle 9 of the rotor SKVT 1 during switching on, failure and abrupt changes x When the voltage U is exceeded: the threshold Ug (Uj.) Of the comparator 13 (14) triggers, it is triggered and the output voltage is 0} 5 (fed to the input of the AND-OR element 18. From the output of the AND-OR element 18, the signal goes to the input of the single-vibration 16, which generates a pulse of starting the register 11 of successive approximations. The operation of the mode switching unit 10 is explained by the timing diagrams in Fig. 3. At the time ti, the error voltage exceeds the threshold g g of the comparator 13, it goes off at U; voltage U. 1 that goes to the first input And-OR 18, the second input of which is an inverted signal to complete the conversion. As a result, the output of the AND-OR element 18 is a voltage that triggers the one-shot 16. From the output of the one-shot 16, an impulse is fed to the trigger input of the register 11 duration that triggers the sequential approximation register 11. At time t, the second output of the sequential approximation register 11 is the voltage that arrives at the load input of the reversible counter code 6 and remains pouring it. The inverted voltage value Uy blocks the passage of stresses and and to the output of the AND-OR element 18 until the completion of the complete conversion cycle. From the moment of time tj, the register 11 of successive approximations starts working with the clock frequency of the generator 15, sequentially, starting with the highest bit, connecting the corresponding bits to the information inputs of the reversible counter 6, the state of which is determined by the comparator 12, the output of which is connected to the information input of the register 11 successive approximations, the first input is connected to the chopper of the amplifier 5, the reference input is applied to the second input. At time tj, the register 11 of successive approximations includes its first most significant bit, which is fed to the information input of the reversible counter 6 and passes to its output, since the enable signal has an enable signal Uif at the load input. From the output of the reversible counter 6, this bit enters the input of the generator of the tangent-cotangent code 19 and from its output to the digital input of the DAC 3, the output of which is the voltage Uj, the value of which is determined by the code at the 191 input, DAC 3. For example W is fed to the second input of the amplifier 5, where it is subtracted from the voltage U, as a result, the error voltage Uj is formed, the polarity of which is determined. The output status of the comparator is equal to 12. At the time t, the register is 11 through 9

ppdovditelnyh approximations podkzet s. teluyiday. the bit to the information input of the rendering counter 6 and turns off the first most significant bit D; as the output of the comparator 12, until t. the low schg voltage is maintained. Correspondingly, the state of the code is also changed on a closed de-counter 6e, since. iia inlet download is present2

; uayushdy signal U., 1 From the output of the reversible counter 15a 6 a new code value is fed to the input of the shaper 19 of the code and from its output to the input of the DAC 3. On the output of the DAC 3 appears 1

new voltage value

Knoe zzchitsaetsya from pruzhzheni

; at the output of the amplifier 5 appears: i:) Boe value of the spreading voltage ;; U, whose polarity determines the output state of the comparator 12. At the same time, the drain voltage1: Ojan decreases in absolute terms; and; , At the time of the time t register i1 of consecutive plots under: l, it is as follows the next bit, without changing the state of the previous one, since on the one of the comparator 12 was preserved for: h; ;; .; The construction of U 1. At the same time ;; apr rykke ./;::::, reconciliation is still a matter of the Lenshäsi “In the subsequent moments of time Cr - t. register 11 consecutive

-; and

The approximation changes the code 3 corresponding to the output 1: cp: comparator 12 so that the error voltage (Jj tends to zero.

FIG. 4 it is conditionally shown j that the register of 11 consecutive approximations has eight bits and, accordingly, eight working cycles t, t .. At the end of the last clock cycle at time t. the conversion completion signal U becomes zero, enabling the operation of the reversible counter 6 in the counting mode, and the converter in the tracking mode. When switching to the next mode, the ctj code is fixed at the output of the reversing counter 6, the digital value of which is equal to the rotation angle 9 of the rotor of the SCRT 1 The inverse voltage value U goes to the second and fourth inputs of the element 18 allowing the passage of the voltages U .. and b to it output at subsequent jumps of the rotation angle of the rotor of the SCRT 1. The converter's settling time is defined as

ten

the breakdown of bits of the register of 11 consecutive approximations, which is equal to the number of bits of the reversible counter b, and the duration of one conversion cycle, which is limited by the voltage setting time at the output of 1-DAP 3. The maximum time for establishing the converter with an accuracy of the least significant bit is

, L. -h-

where sh

reference frequency

1u: time, which determines the duration of the pulse start of the converter;

the time of one conversion cycle;

number of bits of the register 11

n successive approximations.

When the frequency of the reference voltage is 400 Gd (u) 2513 1 / s), the number of register bits is 11 consecutive approximations, the time of one clock cycle t. 10–10 s and the time Ц 20–10 s, the setting time is 7–4510 C5, which is several orders of magnitude shorter than the time required for the converter operating only in tracking mode. The tests performed showed that the calculations coincided well with experiment.

The advantages of the proposed conversion as compared to the known ones are that the conversion accuracy increases 2 times). Obtaining the time to establish the output value at 1 ms, confirmed experimentally, is more than 500 times less than that of the prototype. This expands the application possibilities of the device and allows its use both in single-channel angle transducers varying at high speed and acceleration, as well as in multi-channel multiplexing devices. In the latter case, this leads to a significant reduction in hardware costs while maintaining the dynamic conversion error at the same level. Transducer performance is improved by introducing new elements and changing connections. Along with a significant improvement in the main indicators of the transformation 1111644612

The reader improves and its operational impact on the characteristics of the equipment characteristics, which is still more advanced and increases its manufacturer, most of which is positive.

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Claims (1)

NEXT SHAFT ANGLE CONVERTER TO CODE, containing a sine-cosine rotating trans-! X formator, the outputs of which are connected to the first and second inputs of the octant determinant, a digital-to-analog converter, the output of which is connected to the first input of the amplifier, the output of which is connected to the first input of a phase-sensitive rectifier, the output of which is connected through a low-pass filter to a controlled generator, the outputs of which are connected to the corresponding counting inputs of a reversible counter, a power bus connected to a sine-cosine rotating transformer and a second input of a phase-sensitive rectifier, This is because, in order to increase the accuracy and speed of the converter, / a switch, two reference signal buses, three comparators, a generator, an AND-OR element, a one-shot oscillator, an inverter, a successive approximation register, an EXCLUSIVE OR memory device, are introduced into it , the first output of the switch is connected to the second input of the amplifier, the output of which is connected through the first comparator to the first input of the sequential approximation register, the output of the phase-sensitive rectifier is connected to the first inputs of the second and three comparators, the second inputs of which are connected respectively to the first and second busbars of the reference signal, and the outputs are connected to the first and second inputs of an AND-OR element, the output of which is connected through a single-shot to the second input of the sequential approximation register, the third input of which is connected to the output of the generator, and the outputs are with the third and fourth inputs of the reversible counter, one output of the sequential approximation register is connected through the inverter to the third S and fourth inputs of the AND-OR element, the outputs of the reversible counter are are the outputs of the follower of the angle of rotation of the shaft into the CODE and are connected to the first group of inputs of the EXCLUSIVE OR element, the second group of inputs of which is connected to the outputs of the octant determinant. the input of the octant determinant, the output of which is connected to the control input of the switch, the second output of which is connected to the analog input of the digital-to-analog converter, the outputs The sine-cosine rotating rotary transformer is connected to the first and second inputs of the switch.