JPH0266407A - Control circuit for magnetic resolver - Google Patents

Abstract

PURPOSE:To omit an R/D converter and to obtain an inexpensive detector by executing operation by means of an operational amplifier and a phase difference counter to detect a rotational angle. CONSTITUTION:The frequency of a clock from a clock generator 10 is divided by a frequency divider 11, supplied to the coils 9081, 9082 of a resolver 900 as a sine wave through an LPF 11 and then supplied to coils 9091, 9092 as a cosine wave through a phase adjusting means 14. Respective differences between the coils 9081, 9082 and between the coils 9091, 9092 are added by an adder 19 and a phase having the same phase as an excited sine wave is subtracted from the added value by the adder 19 through a phase adjusting means 16 to obtain a sine wave whose phase is shifted from the excited sine wave by the rotational angle of the resolver. The phase difference is measured by a phase difference counter 23 through comparator 21, 22 to use it as a commutation control signal and the period of an output from the comparator 22 is measured by a period counter 24 to calculate a rotating position.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic resolver interface (hereinafter referred to as 1/F
The present invention relates to a control circuit for a magnetic resolver.

[Prior Art] An example of a conventional magnetic resolver I/F is an R/D converter (resolver/digital converter).

``Problem to be solved by the invention'' However, since the R/D converter is a combination of complex analog IC and digital IC, there is a problem that it becomes very expensive. For example, the R/D converter has a 1-bit Since it costs about 3,000 yen per unit, it will cost 36,000 yen to construct a 12-bit R/D converter.

The present invention has been made to solve these problems, and an object of the present invention is to realize a magnetic resolver control circuit that can configure a magnetic resolver interface at low cost.

[Means for Solving the Problems] The present invention includes a magnetic resolver having teeth similar to those of a pulse motor on a rotor and a stator, and a coil wound around each salient pole of the stator; A signal source that excites a coil wound around a pole with a sinusoidal alternating voltage; and a signal source that adjusts the amplitude and phase of this sinusoidal alternating voltage to generate a cosine-wave alternating voltage; a first adjusting means for electrically removing the error and exciting a coil wound around the other salient pole of the stator with the generated cosine wave AC voltage; subtracting means for subtracting the voltages proportional to the current flowing through the coil excited by the cosine wave from each other; a second adjusting means for adjusting the amplitude and phase of the sine wave AC voltage; Addition of adding together the obtained subtraction signals to calculate a detection signal whose phase is modulated by the rotation angle of the rotor, and correcting the detection signal by adding the signal adjusted by the second adjustment means to this detection signal. means; a phase difference counter that detects a rotational position within one tooth of the magnetic resolver by taking a phase difference between the corrected detection signal and the signal generated by the signal source; and a phase difference counter that measures the period of the corrected detection signal. A period counter; and a position calculation means for calculating the difference between the measurement period of the period counter and the period of the signal generated by the signal source every fixed period, and calculating the rotational position of the magnetic resolver by integrating the differences. This is a control circuit for a magnetic resolver.

[Example] Hereinafter, the present invention will be explained using the drawings.

First, the configuration of the magnetic resolver section will be explained.

FIG. 1 is a diagram showing an example of the configuration of a magnetic resolver used in a control circuit according to the present invention, in which (a) is a front view, and (b) is a sectional view of the Zl-21 portion in Figure <a>.

In the figure, 901 and 902 are two disk-shaped stator members made of magnetic material. Stator members 901 and 9
02, there is a protrusion #19 at each position separated by a rotation angle of 90°.
03 to 9034 and 9041 to 9044 are formed. The tips of these salient poles have teeth 905 with a constant pitch pb.
is formed.

In the same stator member, the phase of the teeth of adjacent salient poles is (1/
2) It is shifted by p b.

Stator members 901 and 902 are stacked with a non-magnetic member 906 inserted therein to form a stator 907.

At this time, the phase of the teeth of adjacent salient poles of the stator is (1/
4) 0 stacked so that they are shifted by P b For example, [! The phase of teeth 9031 and 9041 is (1
/ 4) p b is off.

9081 is a coil wound around salient poles 9031 and 9033,
9082 is a coil wound around salient poles 9032 and 9034. Coils 9081 and 9082 constitute a one-phase coil. Coils 9091 and 9092 are similarly wound around the stator member 902.

910 is a rotor arranged outside the stator members 901 and 902. Teeth 911 are formed on the rotor 910, facing the teeth 905 and having substantially the same pitch as the teeth.

FIG. 2 is a configuration diagram of an embodiment of a magnetic resolver control circuit according to the present invention.

In the figure, 900 is the magnetic resolver portion shown in FIG.

Reference numeral 10 denotes a tarlock generator that serves as a driving signal source for the coil of the magnetic resolver, 11 a frequency divider that divides the frequency of the tarlock generated by the clock generator 10, and 12 a low-pass filter that extracts the low frequency component of the divided clock. (hereinafter referred to as LPF), 13 is a comparator that shapes the waveform of the extracted signal. The shaped signal is an AC voltage (Es1nωt) (
E: amplitude of voltage, ω: angular velocity, t: time) to drive the coils 908 and 9082.

14 is a phase adjustment means, which shifts the phase of AC voltage Es1nωt by 90 degrees to make AC voltage Ecosωt, and electrically corrects mechanical errors in the mounting positions of stator members 901 and 902 (sin core and cos core). do. AC voltage Ec
Coils 9091 and 9092 are excited by osωt.

15 and 16 are amplitude adjusting means and phase adjusting means for adjusting the amplitude and phase of the AC voltage Es1n6Jt.

By such adjustment, the carrier component of the AC voltage Es1nωt is canceled.

17 is a subtractor that calculates the difference between the currents flowing through the coils 908 and 9082 and outputs a voltage proportional to the difference; 18 is the coil 9;
This is a subtracter that takes the difference between the currents flowing through 09 and 9092 and outputs a voltage proportional to the difference.

An adder 19 adds the subtracted values obtained by the subtracters 17 and 18, and adds the signal passed through the phase adjustment means 16 to this added signal to correct the added signal. Here, the corrected addition signal is a signal Ksin (ωt+θ) whose phase is modulated by the rotation angle θ of the rotor of the magnetic resolver (constant).

20 is a band pass filter (hereinafter referred to as BPF) for extracting a specific frequency component of the correction signal of the adder 19; 21.
22 is a comparator that shapes the waveforms of the outputs of the frequency divider 11 and BPF 20.

A phase difference counter 23 counts the phase difference between the signals shaped by the comparators 21 and 22 using the clock of the tarlock generator 10.

24 is a period counter that measures the period of the shaped signal produced by the comparator 22 using the clock of the clock generator 10.

A position calculating means 25 calculates the rotational position of the rotor 910 during one rotation based on the period measured by the period counter 24.

The operation of such an embodiment will be explained.

Since a relative electrical angle error is included between the AC signals Es1nωt and Ecosωt, the coils 908 . 9
08 and 909. 9092 is the AC voltage Es1n(ω
t+ΔA) and Ecosωt (80 is the electrical angle error).

When the rotor 910 rotates by θ, the coil 908
．． 908. 909. Flow to 9092 1 2
The currents I , I , I , and I are as follows.

181=1□ (1+mcos (θ+δA))xs
i n (ωt+ΔA) 01g2=I
□ (1mcos (θ0δA))xsin(ω
t+Δ^) ■ 191=IO(1+ms i nθ) cosωt ■
192=Io (1-m5 inθ)cosωt
■m: constant Here, δA is a relative mechanical error in the mounting positions of the sin core and the COS core.

By the subtractor 17.18 and the adder 19, ■Formula-■Formula+■
The calculation of equation - (2) is performed to calculate the calculation value v1 shown in the following equation.

It is a carrier component included.

The phase adjustment means 14 adjusts the electrical angle of the 0 type, so that Δ^=
By setting δA, the second term on the right side of equation 0 is set to 0.

Further, by adding to this signal a signal -esinωt obtained by adjusting the amplitude and phase of the AC voltage Es1nω, the residual carrier component is canceled.

The phase difference counter 23 measures the phase difference between the carrier component canceled signal θ and the excitation signal θ1 using the tarlock generated by the tarlock generator 10. Since the 360° electrical angle of the excitation signal θ1 corresponds to one tooth pitch of the rotor 910, the phase difference measured by the phase difference counter 23 corresponds to the rotational position within one tooth pitch of the rotor 910. The measured phase difference is used as an address pointer and the RO in which s t n (1i is stored) is
The value of M is read out, and commutation control of the motor whose rotation is detected by the magnetic resolver is performed based on the read data.

The period counter 24 receives a signal θ. The period of is measured using the clock generated by the clock generator 10.

The position calculation means 25 generates a signal θ whose phase is modulated based on the measurement period of the period counter 24. The difference between the periods of the excitation signal θ1 and the excitation signal θ1 is determined at regular intervals.

Since the rotation angle θ of the rotor 910 is vt (v: constant)
, the modulated signal has the form Es1n(ω+v)t. Therefore, the period of the modulated signal changes depending on the rotation angle θ.

Therefore, if the difference in period between the modulated signal Es1n(ω+v)t and the excitation signal Es1nωt is calculated and integrated, the rotor 9
The rotational position of 10 during one rotation is determined.

For example, if the number of clocks required to count one period of the excitation signal θ1 is 4096 and the number of teeth of the rotor of the magnetic resolver is 124, the position calculating means 25 calculates the rotational position from the following equation.

P2Σ (p△choAi - 4oqb) P: 1st rotation, 124x4096= 507,904 clocks are detected.

[effect] According to the present invention, the following effects can be obtained.

■It has a circuit configuration with multiple OP amplifiers, and R/
Lower cost than D converter.

■Since the signal detection force sensing is a phase modulation method, it is easy to configure a digital interface, and it also enables position detection and commutation control of the motor whose rotation is detected by the magnetic resolver.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a configuration example of a magnetic resolver used in a circuit according to the present invention, and FIG. 2 is a configuration diagram of an embodiment of the circuit according to the present invention. 10... Clock generator, 14.16... Phase adjustment means, 15... Amplitude adjustment means, 17.18... Subtractor, 19... Adder, 23... Phase difference counter, 2
4... Period counter, 25... Position calculation means.

Claims (1)

[Claims] A magnetic resolver having teeth similar to a pulse motor on a rotor and a stator, a coil wound around each salient pole of the stator, and a coil wound around some of the salient poles of the stator. A signal source is excited by a sinusoidal alternating voltage, and the amplitude and phase of the sinusoidal alternating voltage are adjusted to generate a cosine-wave alternating voltage, and errors in the mounting positions between the salient poles are electrically removed. , a first adjusting means for exciting a coil wound around another salient pole of the stator with the generated cosine wave alternating current voltage; a subtracting means for subtracting voltages proportional to the current flowing through the excited coil; a second adjusting means for adjusting the amplitude and phase of the sine wave AC voltage; and adding the subtracted signals obtained by the subtracting means. adding means for calculating a detection signal whose phase is modulated by the rotation angle of the rotor, and correcting the detection signal by adding the signal adjusted by the second adjustment means to the detection signal; a phase difference counter that detects a rotational position within one tooth of the magnetic resolver by taking a phase difference between a signal and a signal generated by the signal source; a period counter that measures the period of the corrected detection signal; A control circuit for a magnetic resolver, comprising: position calculation means for calculating the difference between the measurement period of the signal and the period of the signal generated by the signal source at regular intervals, and calculating the rotational position of the magnetic resolver by integrating the differences.