CN103336459B - A kind of digital quantizer conversion plan of autosyn/rotary transformer - Google Patents

Abstract

The invention discloses a kind of digital quantizer conversion plan of autosyn/rotary transformer, the voltage signal that the digital quantizer of autosyn/rotary transformer exports is isolated after amplification through isolated amplifier, sampled by A/D converter simultaneously, after A/D converter completes analog to digital conversion, microcontroller reads the three railway digital signals that A/D converter exports, and by multiplication and division, table look-up, the computing such as summation, export digital angle; The present invention utilizes the various function of software simulating, and circuit is simple, precision is high, low in energy consumption, reliability is high, cost is low.

Description

A kind of digital quantizer conversion plan of autosyn/rotary transformer

Technical field

The present invention relates to a kind of to autosyn/rotary transformer shaft angle signal digitized processing, autosyn/rotary transformer signal is converted to the scheme of the digital signal required for computing machine.

Background technology

Selsyn is used as the displacement transducer taken measurement of an angle in servo-drive system, also can in order to realize the long-distance transmissions of angle signal, conversion, reception and instruction, be widely used in the tracing control of navigation, Aeronautics and Astronautics system, also can be used in the equipment such as numerically-controlled machine and robot.

Rotary transformer is a kind of fine angle, position, speed detector, be applicable to the occasion of all use rotary encoders, particularly high temperature, severe cold, humidity, at a high speed, the rotary encoder such as the high vibrations occasion that cannot normally work, be widely used in the angle in the fields such as servo-control system, robot system, machine tool, automobile, electric power, metallurgy, weaving, printing, Aero-Space, boats and ships, weapons, electronics, metallurgy, mine, oil field, water conservancy, chemical industry, light industry, building, position detecting system.Also can be used for coordinate transform, triangulo operation and angle-data transmission, be used in angle as two-phase phase shifter--in digital switching device.

Autosyn/rotary transformer is as axis angle measurement element, and have that measuring accuracy is high, structure is simple, compare with other measurement of angle scheme, autosyn/rotary transformer has obvious advantage; In control field, in order to adapt to information processing and the control of computing machine, the ac voltage signal by autosyn/rotary transformer exports is needed to become digital quantity.

Autosyn/rotary transformer-digital quantizer the SDC/RDC1740 of the U.S., adopt BiMOS technology, employ miniature transformer, high-speed figure SIN/COS multiplier, error amplifier, phase-sensitive demodulator, integrator, voltage controlled oscillator, up-down counter, make cost very high, and algorithm is more complicated.

In the autosyn/rotary transformer-digitizer technology of China:

Some employings are based on the high voltage integrated circuit of high pressure BiMOS technique, be called in the Chinese patent of " autosyn/rotary transformer-digital conversion schemes of single-chip " as application number is 201010126443.7, be made up of overriding solid-state control transformer circuit, interchange error amplifying circuit, high-pass filtering circuit, phase-sensitive demodulating circuits, Second Order Integral circuit, Voltage-Controlled oscillation circuit, counting circuit and level shifting circuit, there is following problems: circuit structure is too complicated; Use polystage amplifier is connected, and every grade of amplifier all exists zero point drift and temperature drift, and after series connection, drift is progressively amplified; Use Order RC Hi-pass filter, electric capacity can cause phase offset, autosyn/rotary transformer is outputting multiplex signals all simultaneously, when each road signal is processed simultaneously, each road capacitance parameter is difficult to reach consistent, and electric capacity is not trimmed, capacitance error is comparatively large, increases the measuring error of angle; Do not have isolated amplifier in this circuit, in long range propagation, circuit is interfered, and may produce instantaneous pressure, easily damage circuit.

Some employings are based on the low-voltage ic of CMOS technology, if application number is 200810013440.3, in the Chinese patent that name is called " high precision CMOS integrated circuit autosyn/rotary transformer-digital conversion technique ", its voltage only has ± 5V, the amplitude of input signal is less, conversion accuracy is low, and owing to comprising multiple part, electric connecting structure is more complicated, poor stability, output data function is single, and solid-state control transformer circuit adopts switched capacitor technique, has switching noise.

, often there is the defects such as volume is large, integrated level is low, poor reliability, can not apply in the occasion of the high-precision requirement such as real-time tracking system, be unfavorable for promoting the use of in measurement of angle and control field in some employing split-type structurals.

Therefore, need urgent solving the problem, the autosyn/rotary transformer digital conversion schemes that a kind of cost is low, circuit simple, precision is higher, reliability is high is provided.

Summary of the invention

Problem to be solved by this invention is for the deficiencies in the prior art, provides that a kind of cost is low, circuit is simple, precision is high, reliability is high, the digital conversion schemes of the simple autosyn/rotary transformer of algorithm.

The present invention solve the problem adopt scheme be:

Autosyn/rotary transformer signal carries out isolation through isolated amplifier and amplifies.

For selsyn signal

V _S1＝E ₀sinωtsinθ

V _S2＝E ₀sinωtsin(θ+120 ⁰)

V _S3＝E ₀sinωtsin(θ+240 ⁰)

For signals of rotating transformer

V _S1-S3＝E ₀sinωtsinθ

V _S2-S4＝E ₀sinωtcosθ

Reference voltage signal is

V _R＝Esinωt

Wherein: ω is the angular frequency of pumping signal, θ is the shaft angle of autosyn/rotary transformer, E ₀with the maximal value that E is signal voltage and reference voltage respectively.

For selsyn, if S ₃as common port, only need S ₁, S ₂the voltage signal that two ends export:

$V_{S1-S3}=E_0\sin \mathrm{\ωt}[\sin \mathrm{\θ}-\sin (\mathrm{\θ}+{240}^0)]=\sqrt{3}{E}_0\sin \mathrm{\ω}t\sin (\mathrm{\θ}+{30}^0)$

$V_{S2-S3}=E_0\sin \mathrm{\ωt}[\sin (\mathrm{\θ}+{120}^0)-\sin (\mathrm{\θ}+{240}^0)]=\sqrt{3}{E}_0\sin \mathrm{\ω}t\cos \mathrm{\θ}$

V _s1-S3, V _s2-S3, V _rvoltage after isolated amplifier is:

$V_1=\sqrt{3}{K}_0{E}_0\sin \mathrm{\ω}t\sin (\mathrm{\θ}+{30}^0)$

$V_2=\sqrt{3}{K}_0{E}_0\sin \mathrm{\ω}t\cos \mathrm{\θ}$

V ₃＝KEsinωt

K ₀, K is the enlargement factor of isolated amplifier.

For signals of rotating transformer, V _s1-S3, V _s2-S4and V _rvoltage after isolated amplifier is:

V ₁＝K ₀E ₀sinωtsinθ

V ₂＝K ₀E ₀sinωtcosθ

V ₃＝KEsinωt

V ₁, V ₂and V ₃deliver to A/D converter, the data through A/D converter conversion deliver to microprocessor, leave the RAM memory block of microprocessor internal in, are for further processing by microprocessor.

For selsyn, microprocessor carries out computing V ' ₁=2V ₁-V ₂=3K ₀e ₀sin ω tsin θ, by V ' ₁, V ₂, V ₃obtain θ just, cosine formula coefficient is turned to 1:

$\frac{{\mathrm{KEV}}_1^{\text{'}}}{{3K}_0{E}_0{V}_3}=\sin \mathrm{\θ},$ $\frac{{\mathrm{KEV}}_2}{\sqrt{3}{K}_0{E}_0{V}_3}=\cos \mathrm{\θ}$

For rotary transformer, by V ₁, V ₂, V ₃obtain θ just, cosine formula coefficient is turned to 1, microprocessor carries out computing:

$\frac{{\mathrm{KEV}}_1}{K_0{E}_0{V}_3}=\sin \mathrm{\θ},$ $\frac{{\mathrm{KEV}}_2}{K_0{E}_0{V}_3}=\cos \mathrm{\θ}$

Search just, cosine inverse trigonometric function form, show that digital angle φ, φ and θ are very close.

Gained numeral of tabling look-up angle error is θ-φ, in order to reduce error further, by θ just, cosine formula respectively with φ more than, sinusoid is multiplied

sinθcosφ-sinφcosθ＝sin(θ-φ)

Because θ-φ is worth very little, sin (θ-φ) is approximately equal to θ-φ, and then can try to achieve angle θ ≈ φ+sin (θ-φ).

First time when calculating angle afterwards, supposes that gained last time angle is θ after tabling look-up ₁, this actual shaft angle is θ ₂, θ ₁as this φ, then required angle is θ ₂≈ φ+sin (θ ₂-φ).

Make just, the form of cosine inverse trigonometric function, import in microprocessor during programming.

The isolated amplifier of three input ends can be had with one, also can with the isolated amplifier of three identical or different models.

The invention has the beneficial effects as follows: hardware device is few, the many hardware in traditional circuit are all replaced by microprocessor, utilize the various function of software simulating, circuit is simple, reliability is high, more easily realize intellectuality, cost is low, low in energy consumption, conversion accuracy is high; Do not use electric capacity, decrease error; Use isolated amplifier in circuit, avoid the destruction of extraneous high pressure to circuit.

By in conjunction with following accompanying drawing and the explanation to the embodiment of the present invention, there is further understanding to it.

Accompanying drawing explanation

Fig. 1 is the theory diagram of the embodiment of the present invention.

Fig. 2 is software flow pattern of the present invention.

In figure: 1. isolated amplifier, 2.A/D converter, 3. microprocessor, 4. simulating signal 5. digital signal.

Embodiment

As depicted in figs. 1 and 2, a kind of digital quantizer conversion plan of autosyn/rotary transformer, autosyn/rotary transformer voltage signal and reference voltage signal carry out isolation through isolated amplifier and amplify, three simulating signals exported are transformed into digital signal by A/D converter, gained digital signal is delivered to microprocessor and is processed, just obtain shaft angle θ, cosine value, during the signal that microcontroller first time process A/D converter converts, digital angle φ is tentatively drawn by tabling look-up, φ and θ is very close, sin φ is drawn again through counter tabling look-up, cos φ, and with sin θ, cos θ multiplication cross is subtracted each other:

sinθcosφ-sinφcosθ＝sin(θ-φ)≈θ-φ

The shaft angle that precision is higher can be obtained: θ ≈ φ+sin (θ-φ)

After first time tables look-up and obtains an angle value, microcontroller afterwards in the process of data, using last time gained angle as this φ, improve computing velocity.

Isolated amplifier adopts model iso124, A/D to adopt model to be AD7606-4, and single-chip microcomputer adopts STC12C5A60S2.

In signal voltage input end and the additional proportion resistor of reference voltage input terminal of the digital quantizer of autosyn/rotary transformer, it is made to be applicable to autosyn/rotary transformer.For selsyn signal, the numerical procedure of additional proportion resistor is: signal voltage often increases 1V, and respectively at signal voltage input end series winding 1.11k Ω resistance, reference voltage often increases 1V, at reference voltage input terminal series connection 2.2k Ω resistance.For signals of rotating transformer, the numerical procedure of additional proportion resistor is: signal voltage often increases 1V, and respectively at signal voltage input end series winding 2.22k Ω resistance, reference voltage often increases 1V, at reference voltage input terminal series connection 2.2k Ω resistance.

If the line of autosyn/rotary transformer-maximum effective value of line voltage is 11.8V, the maximum effective value of reference voltage is 26V, 400HZ.

For selsyn, S ₃end is as common port, and converter input voltage and reference voltage are respectively:

$V_{S1-S3}=11.8\sqrt{2}\sin \mathrm{\ωt}[\sin \mathrm{\θ}-\sin (\mathrm{\θ}+{240}^0)]=11.8\sqrt{6}\sin \mathrm{\ω}t\sin (\mathrm{\θ}+{30}^0)$

$V_{S1-S3}=11.8\sqrt{2}\sin \mathrm{\ωt}[\sin (\mathrm{\θ}+{120}^0)-\sin (\mathrm{\θ}+{240}^0)]=11.8\sqrt{6}\sin \mathrm{\ω}t\cos \mathrm{\θ}$

$V_R=26\sqrt{2}\sin \mathrm{\ωt}$

If after isolated amplifier:

$V_1=11.8\sqrt{6}{K}_0\sin \mathrm{\ω}t\sin (\mathrm{\θ}+{30}^0)$

$V_2=11.8\sqrt{6}{K}_0\sin \mathrm{\ω}t\cos \mathrm{\θ}$

$V_3=26\sqrt{2}K\sin \mathrm{\ωt}$

For rotary transformer, converter input voltage and reference voltage obtain after isolated amplifier:

$V_1=11.8\sqrt{2}{K}_0\sin \mathrm{\ω}t\sin \mathrm{\θ}$

$V_2=11.8\sqrt{2}{K}_0\sin \mathrm{\ω}t\cos \mathrm{\θ}$

$V_3=26\sqrt{2}K\sin \mathrm{\ωt}$

V ₁, V ₂, V ₃deliver to single-chip microcomputer after being transformed into digital signal by A/D converter, single-chip microcomputer processes digital signal.

For selsyn

Order $V_1^{\text{'}}=2V_1-V_2=35.4\sqrt{2}{K}_0\sin \mathrm{\ω}t\sin \mathrm{\θ}$

$\frac{26K{V}_1^{\text{'}}}{35.4K_0{V}_3}\sin \mathrm{\θ}$

$\frac{26K{V}_2}{11.8\sqrt{3}{K}_0{V}_3}=\cos \mathrm{\θ}$

For rotary transformer

$\frac{26K{V}_1}{11.8K_0{V}_3}=\sin \mathrm{\θ}$

$\frac{26K{V}_2}{11.8K_0{V}_3}=\cos \mathrm{\θ}$

Table look-up and show that digital angle φ, φ and the θ of certain error are very close, counter tabling look-up draws sin φ, and cos φ, obtains

sinθcosφ-sinφcosθ＝sin(θ-φ)≈θ-φ

θ≈sin(θ-φ)+φ

First time table look-up after, in calculating below, using last time gained angle as φ, θ ≈ sin (θ-φ)+φ.

The present invention can make some amendments under the premise of without departing from the spirit of the present invention by those skilled in the art, but the amendment done is still within the protection domain of the claim of the application.

Claims (1)

1. a digital quantizer conversion plan for autosyn/rotary transformer, autosyn/rotary transformer signal carries out isolation through isolated amplifier and amplifies;

For selsyn signal:

V _S1＝E ₀sinωtsinθ；

V _S2＝E ₀sinωtsin(θ+120°)；

V _S3＝E ₀sinωtsin(θ+240°)；

For signals of rotating transformer:

V _S1-S3＝E ₀sinωtsinθ；

V _S2-S4＝E ₀sinωtcosθ；

Reference voltage signal is:

V _R＝Esinωt；

Wherein: ω is the angular frequency of pumping signal, θ is the shaft angle of autosyn/rotary transformer, E ₀with the maximal value that E is signal voltage and reference voltage respectively;

For selsyn, if S ₃as common port, only need S ₁, S ₂the voltage signal that two ends export:

V _s1-S3, V _s2-S3, V _rvoltage after isolated amplifier is:

V ₃＝KEsinωt；

K ₀, K is the enlargement factor of isolated amplifier;

For signals of rotating transformer, V _s1-S3, V _s2-S4and V _rvoltage after isolated amplifier is:

V ₁＝K ₀E ₀sinωtsinθ；

V ₂＝K ₀E ₀sinωtcosθ；

V ₃＝KEsinωt；

It is characterized in that: for selsyn, microprocessor carries out computing V ₁'=2V ₁-V ₂=3K ₀e ₀sin ω tsin θ, by V ₁', V ₂, V ₃obtain θ just, cosine formula coefficient is turned to 1:

$\frac{{\mathrm{KEV}}_1^{\′}}{3K_0{E}_0{V}_3}=sin\mathrm{\θ},\frac{{\mathrm{KEV}}_2}{\sqrt{3}{K}_0{E}_0{V}_3}=cos\mathrm{\θ};$

For rotary transformer, by V ₁, V ₂, V ₃obtain θ just, cosine formula coefficient is turned to 1, microprocessor carries out computing:

$\frac{{\mathrm{KEV}}_1}{K_0{E}_0{V}_3}=sin\mathrm{\θ},\frac{{\mathrm{KEV}}_2}{K_0{E}_0{V}_3}=cos\mathrm{\θ};$

Search just, cosine inverse trigonometric function form, show that digital angle φ, φ and θ are very close; Gained numeral of tabling look-up angle error is θ-φ, in order to reduce error further, by θ just, cosine formula respectively with φ more than, sinusoid is multiplied:

sinθcosφ-sinφcosθ＝sin(θ-φ)；

Because θ-φ is worth very little, sin (θ-φ) is approximately equal to θ-φ, and then can try to achieve angle θ ≈ φ+sin (θ-φ);

First time when calculating angle afterwards, supposes that gained last time angle is θ after tabling look-up ₁, this actual shaft angle is θ ₂, θ ₁as this φ, then required angle is θ ₂≈ φ+sin (θ ₂-φ);

Make just, the form of cosine inverse trigonometric function, import in microprocessor during programming.