SU1580556A1 - Angle-of-turn-to-code converter - Google Patents

Abstract

The invention relates to automation and computing and can be used in digital control systems for converting the angular position of an object shaft to a digital code. In order to improve the accuracy of the converter containing the generator 1 of the reference voltage, sine-cosine sensor 2 angles, selector 3 sectors, functional dividers 4.5, digital inverter 6, summing amplifier 8, phase-sensitive rectifier (FW) 9, voltage converter to frequency 10, reversible counter, amplifier-driver 11, two FChv 12, 13, two analog inverters 14, 15 and summing amplifier 16 are introduced into it. In the converter, voltage generated by the newly introduced elements is used as the reference voltage of the FCF 9 ntami from the phase voltage sensor 2. 1 yl.

Description

The invention relates to automation and computing and can be used in digital control systems for converting the angular position of an object shaft to a digital code.

The aim of the invention is to improve the accuracy of a rotation angle converter into a code by using a phase-sensitive voltage rectifier formed from phase voltages of a sine-cosine angle sensor as a reference voltage.

The drawing shows a functional diagram of the proposed converter.

The shaft rotation angle-to-code converter contains the generator 1 of the reference voltage, sine-cosine sensor 2 (for example, ACST), the sector 3 (quadrant) selector, the function dividers 4 and 5 of the voltage, digital inverter 6, reversible counter 7, summing amplifier 8 , phase-sensitive rectifier 9, voltage-to-frequency converter 10, amplifier-shaper 1, phase-sensitive rectifiers 12 and 13, analog inverters 14 and 15, and summing amplifier 16,

The Converter operates as follows.

When the sine-cosine angle sensor 2 is excited by the voltage from the generator 1 of the reference voltage, the alternating current of the type is induced at the outputs of its phase windings

U.-m- sino6sin (Wt + cf) and

0

Uft-m-coso-sin (+),

where U. is the amplitude of the reference voltage; Ы - frequency reference voltage

neither;

t is the phase shift of the output voltages of the sensor 2 relative to the phase of the reference voltage; m - transformation ratio

sensor 2;

d is the angle of rotation of the sensor shaft 2.

These signals from sensor 2 through the sector selector 3 (quadrant), controlled by the code of the two most significant bits of the reversing counter 7, are fed to the analog inputs of the first 4 and second

0

0

.

five

five

0

0

0

functional voltage dividers. The control inputs of the second 5 function voltage divider from (n-2) low-order bits of the reversible counter 7 receive the code X within the sector (quadrant). The code X enters the control inputs of the first functional divider 4 voltage through the digital inverter 6. The first functional divider 4 voltage implements the function cosX, and the second functional divider 5 voltage implements the function sinX. At the same time, the voltage Uj-m-sine / - cosX-sin (cot + if) is generated at the output of the first functional voltage divider 4, and the voltage U8-m-cos rf-sinX is formed at the output of the second functional voltage divider 5 “Sin (6Ut). These voltages are applied to the first and second inputs of summing amplifier 8, where they are algebraically summed in accordance with the expression

Ue-m-sinc (-cosX-sin (a / t + cf) - Ue-m. Cosof-sinX-sin (U) t + Cf)

 4U. (1)

The error voltage dU from the output of summing amplifier 8 is fed to the input of a phase-sensitive rectifier 9, from the output of which, as a direct current signal, is fed to the input of a voltage-frequency converter 10. The voltage-to-frequency converter 10 produces pulses with a frequency proportional to the amplitude of the input signal, which are fed to the input of the reversible counter 7. At the same time, the code on the reversing counter 7 changes the code until the error signal LU at the input of the voltage converter 10 is not will be equal to zero. When this condition is reached, Kot N, established in the reversible counter 7, corresponds to the angular position of the sensor 2 collapse and is the output code of the converter.

The formation of the reference voltage for the phase-sensitive rectifier 9, which is removed from the output of the summing amplifier -former 16, proceeds as follows. From the outputs of the phase windings of the voltage sensor 2 Ug-ha. (U) t +40 and Ue-m-sin (u) t + (f) are fed to the inputs of the first 12 and second 13 phase-sensitive rectifiers

1580556 to the inputs of the first 14 and second 15 analog inverters, respectively. As the reference voltage of the auxiliary phase-sensitive rectifiers, the excitation voltage U. sin ait passed through the amplifier-shaper 11 is used. The output of the first auxiliary phase-sensitive rectifier 12 produces a voltage Ug ni sinc, and the output of the second auxiliary phase-sensitive rectifier 3 - voltage U-.m-coso /. These voltages are fed to the second inputs of the first 14 and second 15 analog inverters and are control signals for inverting the phase voltages of the angle sensor 2 supplied to the first inputs of the analog inverters. Here, the voltage at the output of the first analog inverter 14 is described by the expression U

m

x

second (sin o () -sin (wt + lf), and at the output of the pRGO analog inverter 15 by the expression Uj-m- (cos oi) -si.n (6b t + (f). Ha summing up the amplifier-former 16 summation

with simultaneous amplification of the resulting signal, i.e. the signal at the output of summing amplifier -former 16 is equal to U op Uem-sin (oot + q) l x (IcosoM Ж, where K is the gain factor.

This voltage, which is a reference for the phase-sensitive rectifier 9, is always in phase with the output voltages of the sensor 2 of the arc, regardless of its angular position, therefore, in the code angle converter, there are no errors caused by the phase shift between the excitation voltage and the output voltage of the sine-cosine sensor when the temperature of its environment changes, and there is no need to use a phase-shifting element.

The absence of frequency-dependent elements in the circuits of analog inverters 14 and 15 of the circuit for the formation of the reference voltage of the rectifier 9 ensures the operation of the shaft angle-to-turn converter at different excitation voltage frequencies of the angle sensor 2 and eliminates the need for adjustment work during operation.

0556 10

15

20

The proposed converter in terms of the formation of the reference voltage is phase-sensitive. The rectifier from the phase voltage of the angle sensor can be used in other devices, for example, in code-angle converters and in drives based on analogue transformer angle transmission systems.

The parameters of the filters located at the outputs of the auxiliary phase-sensitive rectifiers are chosen based on the frequency value of the excitation voltage of the angle sensor. If it is intended to use a shaft angle-to-turn converter circuit with an angle sensor having a different excitation frequency, the filter parameters are selected based on the value of the lowest frequency.

Claims (1)

Invention Formula five 0 0 A shaft rotation angle converter into a code containing a reference voltage generator, the outputs of which are connected to the inputs of a sine-cosine sensor, the outputs of which through the sector selector are connected to the analog inputs of the first and second functional voltage dividers, respectively, the outputs of which are connected to the corresponding inputs of the first summing amplifier , the output of which is connected to the 5 information input of the first phase-sensitive rectifier, the output of which through a voltage to frequency converter with the input of the reversible counter, the outputs of the p-2 low-order bits of which, through a digital inverter, are directly connected to the digital inputs of the first and second functional voltage dividers, respectively, characterized in that, in order to improve the accuracy of the converter, a second amplifier is inserted into it and the third phase-sensitive rectifiers, the first and second analog inverters and the second summing amplifier, one output of the reference voltage generator through the amplifier-shaper connected to the reference inputs and second and third phase-sensitive rectifiers, whose outputs are connected with the control inputs of said first and second analog inverters respectively, the data inputs five 0 five 715805568 a second phase-sensitive straightening E analog inverters connected to the first body and the second analog invertoravhodami summing amplifiers are connected to the first output of the sine-l whose output is connected to a reference cosine sensor informatsionnyevhodom fazochuvsgvitelnogo first inputs of the third fazochuvstvitelnogovypr DC converter outputs two different older rectifier and the second analogue of the reversible counter is connected to the inverter connected to the second output by the control inputs of the selector sine-cosine sensor ka, the exit.