KR910009090B1 - Digital type resolver to digital conversion apparatus - Google Patents

Abstract

The position signal supplied from the resolver is converted to the digital signal by the digital converter, then supplied to the control system with high speed and low error. The position signals detected by a sine winding (L3), and a cosine winding (L2) of the resolver are provided to sample holders (25,26) through differential amplifiers (23,24). The sample signal is generated by comparing the sine output of a reference wave generator (21) to the reference voltage at a comparator (30). A pair of position signals are converted by an A/D converter (28) and processed by a digital signal processor (29), then the absolute position is obtained.

Description

Digital resolver / digital converter

1 is a block diagram of a conventional tracking resolver / digital conversion device.

2 is a block diagram of a digital resolver / digital conversion device of the present invention.

3A to 3D are waveform diagrams of respective parts of the sample circuit and comparator of the present invention.

4 is a waveform diagram of angle division in the digital resolver / digital conversion device of the present invention.

* Explanation of symbols for main parts of the drawings

1,21: reference waveform generator 2,22: resolver

3: sine / cosine multiplier 4: error amplifier

5: synchronous rectifier 6: voltage controlled oscillator

7: Up / down counter 23,24: Differential amplifier

25, 26: sample holder 27: analog multiplexer

28: A / D converter 29: digital signal processing unit

30: comparator L1: reference winding

L2: Cosine winding L3: Sign winding

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resolver / digital conversion device that receives a position signal from a resolver, such as an electric motor, and converts it into a digital value of a position and supplies it to a control system. The present invention relates to a digital resolver / digital conversion device suitable for a control system configuration having a narrow tolerance of time.

The tracking / resolver / digital conversion apparatus of the tracking method widely used in the related art generates a sinusoidal wave (Vo sinωt) of 1 to 10 KHz from the reference waveform generator 1, as shown in FIG. When applied to both ends of the signal, the voltages V1 = Vo sinωt sinθ and V2 = Vo sinωt cosθ are generated at both ends of the sinusoidal winding L3 and the cosine winding L2 according to the rotation angle θ of the resolver 2. / Is applied to the cosine multiplier (3).

At this time, the sine / cosine multiplier 3 internally multiplies the input voltages V1 and V2 by sinø, respectively, and applies an error output V3 such that V3 = Vo sinωt sin (θ-ø), and its output is an error. Amplified by an amplifier (4), the speed signal (V4) is applied through a synchronous current (5) driven by a sine wave generated from the reference waveform generator (1) and through a voltage control generator (6) By driving the up-down counter 7 to form a closed loop with sin (θ-ø) as 0, the internal control system detects the position of the rotor from θ of the up-down counter 7 to θ from the output value ø. .

However, in the conventional tracking / resolver / digital conversion device as described above, when applied to a large number of resolvers, hardware is required in multiples of the multiplexers, which complicates configuration and requires components with high precision. There was a flaw.

In addition, since the maximum rotation speed capable of position measurement is limited due to the limitation of the output frequency of the voltage controlled oscillator 6, it is difficult to apply to a high-speed motor, and the acceleration increases and decreases in proportion to the acceleration and deceleration rate. There was a fault.

In view of such a deficiency, the present invention simplifies the hardware of the product by converting the sine and cosine of the resolver directly into a digital signal in one sampling and calculating the angle by calculating it using a digital signal processing unit. The digital resolver / digital conversion device is designed to not only increase the value but also eliminate the error due to acceleration and deceleration, which will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a digital resolver / digital conversion device according to the present invention. As shown therein, the output sine wave of the reference waveform generator 21 includes the reference winding L1, the cosine winding L2, and the sinusoidal winding L3. And a sample circuit 31 for driving the sample resolver 25 and 26 after passing through each of the differential amplifiers 23 and 24, and outputting the same. The sample circuit 32 and the output sine wave of the reference waveform generator 21 are configured to form the same channel as in (31), and are compared with the reference voltage (V) so that the sample holders (25, 26) Comparator 30 for controlling the signal, an analog multiplexer 27 for selecting the outputs of the sample circuits 31 and 32, and an analog (A) / digital (D) digital conversion for the output of the analog multiplexer 27. Interrupted by the output of the converter 28 and the comparator 30 to the analog multiplexer 27 to select channels 1 and 2. The digital signal processor 29 is configured to output a call, receive the output of the A / D converter 28, calculate an angle within a division section, and obtain a digital absolute position.

3A to 3D are waveform diagrams of the respective parts of the sample circuit and the comparator of the present invention, and as shown in FIG. 3A, the input waveform diagram of the comparator 11, the 3b and c diagrams, and the sample holder 25 and 26 are shown. Is a waveform diagram of the output waveform of the comparator 30. FIG.

4 is a waveform diagram of angle division in the digital resolver / digital conversion device according to the present invention. As shown therein, the magnitudes of the absolute values of the output waveforms of the sample holders 25 and 26 are compared. , And the angle according to the sign is shown as a section (A, B, C, D).

Hereinafter, the effect of the sine wave generated from the reference waveform generator 21 to Vo sinωt is generated and applied to the reference winding L1 and output through the sine winding L3 and the cosine winding L2, and the sine output thereof. The over cosine output is output through the respective differential amplifiers 23 and 24 at voltages such that V1 = Vo sinωt sinθ and V2 = Vo sinωt cosθ.

At this time, after the output sine wave which becomes Vo sinωt of the reference waveform generator 21 is applied to the inverting (-) side of the comparator 30, the reference voltage V on the non-inverting (+) side as shown in a of FIG. As shown in FIG. 3, a sample signal as shown in d of FIG. 3 is outputted, and a differential amplifier thereof as shown in b and c of FIG. The old section is maintained at the voltage V3 (V4) at which the output voltages V1 and V2 of (23) and (24) are V3 = Vo'sinθ and V4 = Vo'cosθ.

On the other hand, when the sample signal, which is the output of the comparator 30, is supplied to the digital signal processor 2 as an interrupt signal, the sample headers 25 and 26 are controlled by controlling the analog multiplexer 27 by the channel 1,2 selection signal. After the output voltages V3 and V4 are selected, they are processed as digital signals by the A / D converter 28 and applied to the digital signal processor 29, where the sample circuit 32 represents resolvers of other channels.

Herein, the digital signal processing unit 29 divides four angles in which the digitally processed Vo'sinθ and Vo'cosθ are A, B, C, and D, as shown in FIG. 4 according to the magnitude comparison and sign of the absolute value. The corresponding section is determined. If x is the quotient of Vo'sinθ and Vo'cosθ divided by the smallest absolute value, x always satisfies 1-≤x≤1.

On the other hand, arctan (x) is expressed as an approximate polynomial to obtain an angle within one division of θ.

However, b1 = 651.334, b2 = -208.955, b3 = 91.513, and b4 = -24.938, where x is substituted to obtain an angle within the arctan (x), i. In this way, the absolute position θ is finally obtained by the following equation.

As described in detail above, the present invention enables the detection of a position in a high-speed motor since the maximum measurable rotational speed is greatly increased, and there is no error increase due to acceleration and deceleration. Therefore, it is advantageous to apply a servo motor control system that emphasizes dynamic characteristics. .

In particular, when the digital control processor and the motor control system are shared, the resolver converter can be installed at a low price, and there is an advantage that the simultaneous conversion of a plurality of resolvers can be performed by adding a simple sample circuit.

Claims (2)

A resolver / digital conversion device for driving a resolver 22 consisting of a reference winding L1, a sinusoidal winding L3, and a cosine winding L2 using a sinusoidal output of the reference waveform generator 21 to receive a position signal and convert it into a digital value. The signal signals of the sinusoidal winding (L3) and the cosine winding (L2) are detected through respective differential amplifiers (23) and (24), and are then input to the sample holders (25) and (26). The sine wave output of the generator 21 is compared with the reference voltage through the comparator 30 to generate a sample signal, and the sample holders 25 and 26 are controlled to sample two position signal outputs as well as a digital signal. Interrupt control of the processing unit 29 to receive the two position signals through the analog multiplexer 27, and then digitally convert through the A / D converter 28, the digital signal processing unit 29 through the A / D Digital calculation of the output of the transducer 28 to calculate the digital absolute position The resolver of the digital system / digital converter, characterized in that the W. The method according to claim 1, wherein the corresponding one of the four angle division sections (A, B, C, D) is determined according to the magnitude comparison and the sign of the absolute value from the two digital position data, and the smaller absolute value is divided by the larger one. The quotient is calculated by the variable (x), and the arctan (x) is calculated by setting the approximate polynomial arctan (x) = b1x + b2x ³ + b3x ⁵ + b4x ⁷ as the variable (x), and the four angle division intervals. According to (A, B, C, D)

A digital resolver / digital converting apparatus, characterized by calculating a digital absolute position θ.

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