SU840997A1 - Shaft angular position- to-code converter - Google Patents

Description

(54) CONVERTER ANGLE OF TURNING SHAFT INTO CODE

one

The invention relates to a measurement technique and is intended to convert angular movements into a digital code.

Angular displacement transducers for the electrical signal phase are known, which include an amplitude modulator, a phase shifter, amplitude detectors, selective amplifiers, differential amplifiers, and a phase-shifted QC circuit in which the angle conversion scale doubling is achieved, as well as improved accuracy of operation due to the fact that the phase shifter is working in the most favorable high-frequency range, and the phase measurement occurs at a low frequency fIj.

However, the presence of selective amplifiers in these devices, as well as phase-shifting RC circuits, causes the appearance of a conversion error determined by the phase instability of the frequency-dependent circuits.

The closest in technical essence to the present invention is a converter with a modulation of the conductivity of the output circuits, which contains a crystal oscillator, a divider

frequencies, sinusoidal power drivers connected to the first frequency divider, two-phase sinusoidal oscillators connected to the second frequency divider, an induction phase shifter, a phase-modulated signal frequency converter connected to the output windings of the phase arrays and two-phase

o sinusoidal oscillators, the frequency converter of the reference signal connected to the sinusoidal power supply and two-phase sinusoidal heterodyne, two

5 low frequency filters, one of which is connected to the output of the frequency converter of the phase-modulated signal, and the second to the output of the reference frequency converter

0 and pulse drivers connected to the outputs of low-pass filters 2.

An increase in accuracy is achieved by obtaining an effect similar to that of the inverse filter, of a sequence. Due to this, errors caused by the power failure of the phase shifter are eliminated.

The disadvantage of this transform is the errors caused by the use of low-pass filters in it.

In addition, the presence of inertial links in the converter, such as low-pass filters, leads to the deterioration of its dynamic characteristics and, consequently, to the occurrence of an additional error due to rapid changes in the input angle.

So, for example, if a low-pass filter consists of three links with boundary frequencies Schr 1500 G and the signal frequency tiJ 1000 Hz, then the support introduced by the filter will be 0.64 ms.

The purpose of the invention is to improve the accuracy of the converter of the angle of rotation of the shaft into a code.

The goal is achieved by the fact that the shaft angle converter is converted into a code containing a generator whose output is connected to the inputs of two frequency dividers, the output of the first of which is connected to the input of a two-phase sinusoidal voltage generator, the outputs of which are connected to the inputs of the phase shifter, three pulse formers, the output of the first of which is connected to the first input of the converter, a phase code, two correlators are introduced, an adder and a pulse width selector, and the input of the first pulse former is co Inen with one of the outputs of the two-phase sinusoidal voltage shaper, the inputs of the two other pulse shapers are connected to the corresponding outputs of the phase shifter, and the outputs are connected to the first inputs of the correlators, the second inputs of which are connected to the output of the second frequency divider, the outputs of the correlators are connected to the inputs of the adder, the output which is connected to the input of the pulse width selector, the output of which is connected to the second input of the phase encoder.

FIG. 1 shows the functional diagram of the converter of the angle of rotation of the shaft into the code; in fig. 2 - time diagrams) AMG & 1 converter operation. ,

The converter contains generator 1, first divider 2 frequencies, second divider 3 frequencies, shaper 4 two-phase sinusoidal voltage, phase shifter 5c primary 5-1 and secondary 5-2 windings, shapers 6-8 pulses, correlators 9 and 10, adder 11, the selector 12 of the pulse duration and the Converter 13 phase-code (figure 1),

The Converter operates as follows. .

Impulse voltage with frequency f | from generator 1 is fed to the inputs of the first and second dividers 2 and 3

frequencies with division factors K and Kd, with K # Kg; . From the output of the first divider 2 frequency, the pulse sequence is fed to the input of the shaper 4 of a two-phase sinusoidal voltage, the outputs of which are separated by two voltages

U, -UoCOsu t.

and

U s Uo & Intu t

with equal amplitudes of Vg

and frequency2TCf mi sh. Voltage U,

retardations If 1 .A "ИЫ1. / Ь1.Ь (I,

K, l

on phase 90 al. with respect to the voltage U,. These voltages are fed to the inputs of the phase actuator 5, which operates in a rotating field mode.

If, for some reason, the rotation field of the phase shifter is elliptical and contains a reverse-rotation component with a relative amplitude a, then its output quadrant Ua and id

field voltage

can be represented as

Uo, (a), (a t-zoJ + V,) cioos (aJ -fc-Zo,

where Vf is the amplitude of the output voltage of the phase shifter; scale conversion angle;

the rotation angle of the rotor phase 6 rotator;

V Mp

the initial phase shift of the reverse rotating component. The output voltages of the phase shifter DO, and applied to the formers 7 and 8 pulses, which form the pulse sequences 5 (and, 5),

U (, sign (U)

From the outputs of the formers (Fig. 2), the pulse sequences are fed to the first inputs of the correlators 9 and 10, to the second inputs of which (The pulsed voltage flows (in

7K f

With a frequency of Na. from the second

Divider 3 frequencies

. (M,),

-J

where uq. - the amplitude of the pulses.

At the outputs of the correlators 9 and 10, we have the mutually correlation functions “67 (“ T Cf)

Claims (2)

"DtCrg co9 C4-to, j) pi; -zai -f h-aso" {(s) -Zot- „Rc, 7 No.) (cos (u.-4) pt - 2al, j- d) - U) 2) pt: -f The pulse sequences corresponding to the input and output voltages of the correlators 9 and 10 are shown in the timing diagram (Fig. 2 From the outputs of the correlant tor 9 and 10, the signals Rg7 C) and R (T) arrive on the adder) 11, the output of which is and -21 () pt-Zdi f- p-. From this expression, it is clear that the reverse rotator with the component of the phase rotator is not contained in the output signal at all and therefore does not need to be filtered. The proposed device has an effect similar to that of the reverse sequence filter, which allows significantly reducing the effect of electrical and magnetic asymmetry of the phase rotator. From the output of the adder 11, the signal goes to the pulse width selector 12, which determines the condition for the existence of a correlation link. The output pulses of the pulse width selector 12 are fed to the inverter 13 of the phage code and are used as a signal pulse sequence. The pulses received from the pulse former are used as the reference pulse sequence. The connection of the pulse former 6 to the output of the dual phase sinusoidal former 4 makes it possible to eliminate the conversion error associated with the drift of the phase characteristic of the latter. Since, with a possible drift of the phase characteristic of the former 4 of a two-phase sinusoidal voltage, the reference pulse sequence and the pulse sequence carrying information about the input angle are mixed in phase by the same magnitude. The phase shifter is powered by the high-frequency voltage and the phase is measured at a low frequency. which allows to obtain high resolution of the converter and thereby reduce the requirements for electronic information processing circuits. The economic effect of the use of this invention is due to its technical features. Claims of the shaft angle converter into a code comprising a generator, the output of which is connected to the inputs of two frequency dividers, the output of the first of which is connected to the input of a two-phase sinusoidal voltage driver, the outputs of which are connected to the inputs of the phase shifter, three pulse shapers, the output of the first of which is connected With the first input of a phase-code converter, characterized in that, in order to improve the accuracy of the converter, two correlators are introduced into it, an adder and a pulse duration selector the input of the first pulse generator is connected to one of the outputs of the two-phase sinusoidal voltage driver, the other two pulse formers are connected to the corresponding outputs of the phase shifter, and the outputs to the first inputs of the correlators, the second inputs of which are connected to the output of the second frequency divider, the outputs of the correlator are connected with entrances of the equator, the output of which is connected to the input of the pulse duration selector, the output of which is connected to the second input of the phase-code converter. . Sources of information taken into account in the examination 1. USSR author's certificate 569843, class, G 01 В 7 / 30,1975. 2. Electrotechnical angle transducers with electrical reduction. Ed. A.A. Akhmetzhanova.M., Energie, 1978, p. 143-148 (prototype). ABOUT,