SU1320902A1 - Shaft angle position-to-time digital converter - Google Patents

Abstract

The invention relates to automation and computing and can be used to connect analog information sources with a digital computing device. In order to increase the dynamic accuracy by correcting the frequency response to a converter containing a sine-cosine sensor 1 of rough counting, a sine-cosine sensor of accurate counting 2, demodulator 3, digital-to-analog converters (D / A) 4 and 5, the first sine-co with to

Description

sine generator 7, digital adders 8 and 9, analog adder 10, generator P of the reference frequency, functional conversion unit 12, channel selection unit 13, unit, voltage-to-frequency conversion 1A, reversible counter 15, a second SN-generator 6, analog-to-digital converter 16, control and processing unit 17, comparators 18 and 19. The output voltages of sensors 1 and 2 are demodulated | in demodul torus 3, DAC 4 and 5. Output 1

The invention relates to automation and computing and can be used to connect analog information sources with a digital computing device.

The purpose of the invention is the evolution of the dynamic accuracy of the converter. by digital correction of its frequency response.

FIG. 1 is a block diagram of a converter; in fig. 2 - a mathematical model of one of the implementations of the exact reference channel of the converter.

The shaft rotation angle-to-code converter contains a coarse-count sine-cosine sensor 1 (SKDGO), a precision-read sine-cosine sensor 2 (SKDTO), a demodulator 3, digital-to-analogue converters (DAC) 4 and 5, sine-cosine generators 6 and 7, digital adders 8 and 9, analog adder 10, reference frequency generator 11, block 12 of the functional code converter, block 13 of channel selection, block 14 of voltage-to-frequency (PVC) conversion, reversible counter 15, analog-to-digital converter ( LTSP) 16, control and processing unit 17, computer Ratters 18 and 19.

Sine-cosine generators 6 and 7 are a functional code converter. Into sine and cosine codes, the outputs of which are connected to the digital inputs of the corresponding D / A converters, the output signal of the DAC between the angle and the code from the outputs of the demodulator 3 and the analog adder 10 through the block 13 is fed to the input of the digital integrator formed by the blocks 14, 15, and the input of the ADC. The resulting codes are processed by block 17 to provide the specified dynamic characteristics and, through the feedback circuit, the output code of block 17 affects the excitation voltage of sensors 1 and 2, compensating for the phase angle of rotation of the sensor. 2 Il.

Lena power amplifiers. The reference frequency generator 11 is a series-connected pulse generator and frequency divider. The control and processing unit 17, which can be performed, for example, on a 1ARH-186 micro-computer, contains an arithmetic logic unit, memory access and interrupt controllers, a micro-command counter, a clock signal generator, and buffer registers.

The converter is a pulse tracking system, which, depending on the angular mismatch, is formed by blocks 9,

7.1,3, 13, 14, 15, 16, 17, 9 or

8.6, 2, 4, 5, 10, 13, 14, 15, 16, 17, 8.

The Converter operates as follows.

The generator 11 generates the digital equivalent of the argument cot, which is converted by the functional conversion unit 12 to the cos ot and sin cot function code, and digital adders 8 and 9 and sine-cosine oscillators 6 and 7 to the analog excitation voltages of sensors 2 and 1 UQsin ( cot-N), UgCosCot-Njc) and UpSin ((ot-N), UgCos (cot-N), respectively, where K is the electrical reduction ratio. The digital adder 8 receives the lower bits of the output code and, and the digital adder 9-t high bits of the code N, the number of bits of which is Pn + m - 1.

R P

At the same time, K 2, Digital adder

in conjunction with a sine-cosine generator, perform the function of digital-analog conversion

code N .. or K to ts analog values

the phase of the excitation voltage of the corresponding angle sensor 2 and 1. .

The output phase-modulated voltages of the fine-reading sensor 2 and sin (cot-Nn + oi-) and U cosCwt-Njj + oi) are multiplied by digital-to-analogue converters 4 and 5 by the codes of the mutually orthogonal functions coswt and sin cot. After subtraction in the analog adder 10, a voltage is formed at its output.

Y ,,. (O6- Y,).

Voltage with secondary winding

t5 co. The output voltage of the analog adder 10 is different from zero and at you the progress of the comparator 18 (dual comparator with a window) a signal appears that permits on the input of the gating

Coarse sensor U 1, cos (ut - 20, the operation of comparator 19, which is N + about) is fed to the input of the demodus.) 1 of the 3, which uses the high voltage of the generator 11 as a reference. Output voltage of the demodule torus 3 after filtering with the help of its low-pass filter has the form

25

(-N + o6). Since the coarse channel is necessary to eliminate the ambiguity of samples, only one demodulator 3 is used in the relay synchronous detection mode.

The output voltages of the channels are roughly30

It detects a pulse at the moment of zero crossing of the output voltage of the coarse angle sensor 2. Under the influence of this impulse, block 17 performs the interdiction of the execution of the main mode of operation and executes the mode of matching the samples. In the output register of block 17, the generator code 11, corresponding to the moment of arrival of the pulse at the interruption, is entered, thereby implementing the running gating mark method. This code corresponds approximately to the angular position of sensor 1, therefore

th and accurate readings through block 13 35 follow coarse reference system

channel selection is received at the input of the unit changes the code until, when the voltage conversion voltage is 14

frequency of the fnu to convert them to

sequential code followed

summation in a reversible counter

15. Block 14 together with reversible

40

the driving voltage of demodulator 3 decreases to zero, i.e. Uabix e Ujsin (K-oi) Oh, whence N; tA with an accuracy of the smallest bit of a rough reference, i.e. N about + + NK / 2.

counter 15 performs digital integration of the following system error signal. Simultaneously this

the driving voltage of demodulator 3 decreases to zero, i.e. Uabix e Ujsin (K-oi) Oh, whence N; tA with an accuracy up to the value of the younger time is the row of a rough reference, i.e. N about + + NK / 2.

As soon as Ugbix-v- O (code APP 16

the signal is digitally transformed - also reduced to zero), block 17

Analog-to-digital converter 16. The output codes of the reversible counter 15 and the A / D converter 16 are fed to the corresponding inputs of the block 17, which selects a reference channel (sample matching) digital processing of proportional (through A / D converters) and integral (via IFF and reversible counter) control signals tracking system, digital correction of its frequency response, generation and fixation of the output code N, which arrives

209024

to digital adders 8 and 9. This closes the feedback in the corresponding follow system.

Depending on the magnitude of the angular mismatch, the following system is formed by blocks 9, 7, |, 3, 13, 14, 15, 16, 17, 9 with / N-oi / i 360 ° / 2 or by blocks 8, 6, 2, 4, 5, 10, 13, 14, 15, 16, 17, 8 with / N-06/360 ° / 2.

W When the converter is turned on by the command of block 17, channel selection unit 13 includes a coarse channel in the tracking system, since the angular mismatch is large enough to 5. The output voltage of the analog adder 10 is different from zero, and the output of the comparator 18 (dual comparator with a window) is a signal that permits on the gate input

the job of comparator 19 which is odds

It detects a pulse at the moment of zero crossing of the output voltage of the coarse angle sensor 2. Under the influence of this impulse, block 17 performs the interdiction of the execution of the main mode of operation and executes the mode of matching the samples. In the output register of block 17, the generator code 11, corresponding to the moment of arrival of the pulse at the interruption, is entered, thereby implementing the running gating mark method. This code corresponds approximately to the angular position of sensor 1, therefore

the driving voltage of demodulator 3 decreases to zero, i.e. Uabix e Ujsin (K-oi) Oh, whence N; tA with an accuracy of the smallest bit of a rough reference, i.e. N about + + NK / 2.

As soon as Ugbix-v- O (code APP 16

0

five

using the channel selection unit 13, it includes into the next system an accurate reference channel and proceeds to perform the basic mode of operation, which at the initial stage provides for a transient process that is optimal in speed from the point N cJ- + to the point W aj with an accuracy of the least significant bit countdown.

In this case, the voltage mismatch at the output of the adder U is zero, the comparator IS locks the input

gating a comparator 19 and an interrupt pulse is not generated.

Depending on the requirements of the converter for speed and the size of the dynamic error, block 17 is the desired frequency response of the exact reference channel system. FIG. 2 depicts a mathematical model of one.

implementations of the impulse-dependent servo system In this diagram, W, (w)

 TO,

(1 + T, U) (1-Tau)

- gear

M W function implemented by block 17;

I -T W

W ... (w) K, - transfer

CPU {- -tf

digital integrator function; PFC - code-phase converter. The set of blocks 2, 4, 5, 10 (see Fig. Is equivalent to a block with an output voltage varying according to the law 10 sin (() i, -N) t), at the input of which the angular error (r-N) acts . Consequently, its transfer coefficient is K 10 / 1G. The final transfer function of the pulse tracking system can be written as

„(,,, о) К (.l) (l-T.v)

V

Thus, when implementing the invention with a digital integrator as a correction device, performing calculations in accordance with the algorithm

N (n) a, M (n-1) + a. H (-n - 2} + + b, W (n-1) + b, jN (n-2)

where N (n), N (n-l), N (n-2) are the values of the output code, calculated in the corresponding cycles;

.N (nl), W (n-2) is the total code of the digital integrator and the ADC, measured in the corresponding cycles, the converter acquires the properties of a third-order astatic tracking system, which does not have dynamic errors in speed and acceleration when the input angle changes la with constant acceleration.

To eliminate instrumental error, the control unit and

g 5 W

15

20

 ) thirty

es 40

50

45

55

Processing mainly provides for the correction mode of the output code with the help of corrections recorded in the permanent memory of the specified block at the stage of metrological certification of the converter.

Claims (1)

Invention Formula Shaft rotation angle converter into a code containing a 1st coarse sine-cosine sensor, the output of which is connected to one input of the demodulator, the output of the demodulator is connected to one information input of the channel selection unit, a sinus-cosine sensor of the exact reading, whose inputs connected to the outputs of the first sinus-cosine generator, and the first and second outputs are connected to the analog inputs of the first and second digital-to-analog converters, respectively, the digital inputs of the first and second digital-to-analog converters the distributors are connected to the corresponding outputs of the functional code conversion unit, and the outputs are connected to the inputs of an analog adder, the output of which is connected to another information input of the channel selector unit, the output of the channel selection unit is connected to the input of the voltage-to-frequency conversion unit, the outputs of which are connected to the reverse counter inputs The reference frequency generator, the outputs of which are connected to one group of inputs of the first and second digital adders, is distinguished by the fact that, in order to increase the number the second transducer, the second sine-cosine generator, the first and second comparators, the analog-to-digital converter and the control and processing unit, the outputs of the first and second digital totalizers are connected to the inputs of the first and second sine-cosine generators, the second sine -cosine generator connected to the inputs of the sine-cosine coarse-reference sensor, the output of the analog adder through the first comparator is connected to the building input of the second comparator, inf The input input of which is connected to the output of a coarse-count sine-cosine sensor, and the output of the plug to the interrupt input of the control and processing unit, the outputs of the reversible counter, analog-digital converter and reference frequency generator are connected to the first, second and third ports, respectively. control and processing unit, information outputs of the fallen and high bits of the control and processing unit are converter outputs and are connected to another group of inputs of the first and second digits respectively. Compiler E, Budarina Editor M. Petrova Tehred V. Kadar Corrector L. Pilipenko 2667/56 Circulation 9Q1 Subscription VNSHPI State Committee of the USSR for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., d. 4/5 Production and printing company, Uzhgorod, st. Design, And level adders, the first and second outputs of the control unit and the processing unit are connected to the control inputs of the channel selection unit and the analog-digital converter, the information input of which is connected to the output of the channel selection unit, the outputs of the reference frequency generator are connected to the inputs of the function conversion unit, one generator output the reference frequency is connected to another input of the demodulator. ts (i) FIG. 2