JPH0559367B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a device for detecting position and velocity using a magnetic resolver.

[Prior art] Conventionally, such a position/velocity detection device
For example, there was one shown in Figure 5.

This device is a multipolar resolver using a motor stator and rotor core.

In the figure, L ₁ , L ₂ , and L ₃ are three-phase coils wound around the salient poles of the stator, and 1 is one end of the coils L ₁ , L ₂ , and L ₃ .
A voltage source that applies a voltage Esinωt (E is amplitude, ω is angular velocity, t is time), A ₁ , A ₂ , A ₃ are coils
an amplifier that amplifies the potential difference at the other ends of L ₁ , L ₂ , and L ₃ ;
2 is the three-phase output V _A , V _B , of amplifiers A ₁ , A ₂ , A ₃ ,
A Scotto converter converts _VB into a two-phase signal, and 3 is an R/D converter that outputs the rotation angle θ as a digital signal from the output of the Scotto converter 2.

In this device, if the rotation angle of the rotor core is θ, the inductance of each coil changes as shown in the following equation.

L ₁ = L _C (1+Msinθ) L ₂ = L _C {1+Msin(θ+120)} L ₃ =L _C {1+Msin(θ−120)} L _C , M: constant In this formula, coils L ₁ , L ₂ , L The inductance of ₃ is also represented by the same symbol.

When each coil is driven by applying a voltage Esinωt from the voltage source 1 and the potential differences V ₁ , V ₂ , and V ₃ of each coil are taken by the amplifiers A ₁ to A ₃ , the following is obtained.

V ₁ = V ₀ sin θ sin ωt V ₂ = V ₀ sin (θ + 120) sin ωt V ₃ = V ₀ sin (θ - 120) sin ωt V ₀ : Voltage amplitude When these voltages are subjected to Scott conversion, the signals of sin θ sin ωt and cos θ sin ωt are extracted. .
When these signals are applied to the R/D converter 3, the rotation angle θ is obtained as a digital signal.

[Problems to be Solved by the Invention] However, in this device, if there is an error in the mechanical angle of the salient pole, an error occurs in the phase of the inductance of the coils L ₁ , L ₂ , and L ₃ . This causes an error in the detection signal. Further, detection errors also occur due to errors included in the electrical angle of the alternating current signal for exciting the coil.

In order to eliminate such errors, we provide a pair of salient poles with differential coils, and generate signals with a 180° phase difference from the voltage induced in the coils wound around these salient poles. , there was one in which the error component of the detection signal was canceled by taking the difference between the generated signals. However, even with this method, error removal was insufficient.

The present invention was made to solve these problems, and by adjusting the phase of the excitation signal of the coil, it is possible to compensate for both the mechanical angle error of the salient pole and the electrical angle error of the excitation signal. The object of the present invention is to realize a position/velocity detection device that can effectively remove error components that occur when

[Means for Solving the Problems] The present invention includes a first salient pole having teeth formed at a constant pitch at its tip, and teeth whose phase is shifted by 1/2 pitch with respect to the teeth of the first salient pole. a second salient pole formed at its tip; a third salient pole whose tip is formed with teeth whose phase is shifted by 1/4 pitch with respect to the teeth of the first salient pole;
A stator is provided with a fourth salient pole whose tip is formed with teeth whose phase is shifted by 1/4 pitch with respect to the teeth of the salient pole, and the teeth of each salient pole provided on this stator are approximately the same. A rotor in which pitch teeth are formed at positions facing the teeth of each salient pole, and the rotor is wound around the first salient pole, and as the rotor rotates, the inductance becomes L ₀ {1+m _b sin (θ+
δ _A )} (L ₀ : constant, m _b : constant, θ : phase difference between rotor teeth and first salient pole tooth, δ _A : mechanical angle error of salient pole) 1 coil and the second salient pole, and as the rotor rotates, the inductance becomes L ₀ {1−m _b sin (θ+
δ _A )} is wound around the third salient pole, and as the rotor rotates, the inductance changes to L ₀ {1+m _b cos(θ+
δ _B )} (where δ _B is the error in the mechanical angle of the salient pole), and the third coil is wound around the fourth salient pole, and the inductance changes as the rotor rotates _. {1−+ _b cos(θ+
δ _B )}, and the first and second coils are changed to V ₁ cos(ωt+Δ _A ).
(where, V ₁ : amplitude voltage, Δ _A : electrical angle error of AC voltage), the third and fourth coils are excited by V ₁ sin (ωt + Δ _B ) (where Δ _B : AC voltage). a signal source that is excited with an alternating current voltage (error in electrical angle of voltage) and induces voltages V _S1 , V _S2 , V _C1 and V _C2 given by the following equations at both ends of the first to fourth coils, respectively; V _S1 =V ₁ {1+m _b sin(θ+δ _A )} ×cos(ωt+Δ _A ) V _S2 =V ₁ {1−m _b sin(θ+δ _A )} ×cos(ωt+Δ _A ) V _C1 =V ₁ {1+m _b cos (θ + δ _B )} × sin (ωt + Δ _B ) V _C2 = V ₁ {1−m _b cos (θ + δ _B )} × sin (ωt + Δ _B ) For the voltage induced across each coil, V _S1
Perform the calculation −V _S2 +V _C1 −V _C2 , and get V _b = m _b {sin(ωt+θ+δ _A +Δ _A ) +sin(ωt+θ+δ _B +Δ _B ) +2sin{(Δ _B −δ _B −Δ _A +δ _A )/2 _} × _cos {ωt−θ ₊ ( _{Δ B} −δ _B +Δ _A −δ _{A / 2} } and a calculation unit that adjusts and _ΔB and sets the second term of the equation giving the calculation value V _b to 0.

[Example] The present invention will be explained below using the drawings.

FIG. 1 is a block diagram of an embodiment of a position/velocity detecting device according to the present invention, in which a is a front view and b is a cross-sectional view of a section Z ₁ -Z ₁ in FIG.

In the figure, 901 and 902 are two disk-shaped stator members made of magnetic material. Stator members 901 and 902 have salient poles 903 ₁ to 903 ₄ and 904 _{1 to} 90 at positions separated by a rotation angle of 90°.
4 ₄ is formed. Teeth 905 are formed at a constant pitch p _b at the tips of these salient poles.

In the same stator member, the phases of adjacent salient pole teeth are shifted by (1/2) p _b . For example, salient pole 9
The phases of the teeth of 03 ₁ and 903 ₂ are shifted by (1/2) p _b .

Stator members 901 and 902 are non-magnetic members 9
06 are inserted and stacked to form a stator 907. At this time, the teeth of adjacent salient poles of the stator are stacked such that the phases of the teeth are shifted by (1/4) p _b . For example, the positive poles 903 ₁ and 904 ₁
The phases of the teeth are shifted by (1/4) p _b .

908 ₁ is a coil wound around salient poles 903 ₁ and 903 ₄ ; 908 ₂ is a coil wound around salient poles 903 ₂ and 903 ₄ ; These coils 908 ₁ , 908 ₂
A one-phase coil is formed. Similarly, coils 909 ₁ and 909 ₂ are wound around the stator member 902 as well.

Here, the first salient pole, second salient pole, third salient pole, and fourth salient pole in the claims are each salient pole 9.
03 ₁ and 903 ₃ , 903 ₂ and 903 ₄ , 904 ₁ and 9
Corresponds to 04 ₃ , 904 ₂ and 904 ₄ . In addition, the first coil, the second coil, the third coil, the fourth coil
The coils have salient coil poles 908 ₁ and 90, respectively.
This corresponds to 8 ₂ , 909 ₁ , 909 ₂ .

910 is a rotor placed outside the stators 901 and 902. The rotor 910 has teeth 90
5, and teeth 911 having approximately the same pitch as these teeth are formed.

912 is a signal source that provides an alternating current voltage signal or an alternating current signal to the coils 908 and 909 of each phase. The AC signals applied to coils 908 and 909 have a phase difference of 90°.

913 is an arithmetic unit that detects the voltage or current across the coils 908 and 909, adds and subtracts them, and calculates the rotational position of the rotor 910 from the phase of the addition/subtraction signal, and the rotational speed from the frequency.

As a detection circuit for detecting current or voltage at both ends of a coil, there are circuits having the configurations shown in FIGS. 2 to 4, for example. The circuit shown in FIG. 2 detects the voltage across the coil, the circuit shown in FIG. 3 detects the voltage across the coil, and the circuit shown in FIG. 4 uses a transformer to detect the voltage.

Next, the operation of such a rotation detection section will be explained.

The signal source 912 has coils 908 ₁ and 908 ₂
Applying an AC voltage of V ₁ cos (ωt + Δ _A ), the coil 9
An AC voltage of V ₁ sin (ωt+Δ _B ) is applied to 09 ₁ and 909 ₂ (V ₁ is the amplitude voltage, and Δ _A and Δ _B are electrical angle errors).

When the rotor 910 rotates by an angle θ, the voltages V _S1 , V _S2 , V _C1 , and V _C2 across the coils 908 ₁ , 908 ₂ , 909 ₁ , and 909 ₂ are as follows.

V _S1 = V ₁ {1+m _b sin(θ+S _A )} cos(ωt+Δ _A ) V _S2 = V _E {1−m _b sin(θ+S _A )} cos(ωt+Δ _A ) V _C1 = V ₁ {1+m _b cos( θ+S _B )} sin(ωt+Δ _B ) V _C2 = V ₁ {1−m _b cos(θ+S _B )} sin(ωt+Δ _B ) m _b : Constant, δ _A , δ _B : Mechanical angle error The calculation unit 913 is Detect the voltage across these ends,
A calculation value V _b shown in the following equation is calculated by performing the calculation of equation - equation + equation - equation.

V _b = m _b {sin(ωt+θ+S _A +Δ _A ) +sin(ωt+θ+δ _B +Δ _B )} +2sin(Δ _B −δ _B −Δ _A +δ _A /2) cos(ωt−θ+Δ _B −δ _B +Δ _A −δ _A /2) In the equation, by adjusting the electrical angle to make Δ _B - δ _B - Δ _A + δ _A = 0, the second term on the right side of the equation becomes 0, and the phase accuracy can be improved.

Note that the number of salient poles provided on one stator member and the number of stator members may be other than those shown in the embodiments.

When one stator member is provided with n _b salient poles and k _b stator members are provided, the respective values are as follows.

Phase shift of teeth between adjacent salient poles in the same stator member: P _b /2 Phase shift of teeth between adjacent salient poles when stator members are stacked: {{1/2k _b ) + m _b } ( When k _b = 2) {{1/k _b ) + m _b } When k _b is an integer other than 2) m _b : Integer Number of coil phases: k _b Each AC voltage or AC current for driving the coil Phase difference between phases: 360°/2k _b (when k _b = 2) 360°/k _b (when k _b is an integer other than 2) In addition, in the example, the phase of the teeth of adjacent salient poles of the stator is Although we explained the case of a shifted configuration,
The rotor is not limited to this, and the rotor may have a laminated structure of k _b layers, and the phases of the teeth of adjacent layers may be shifted in the same manner as the adjacent salient poles in the embodiment.

[Effect] In the present invention, the phase of the coil excitation signal is adjusted so that the second term on the right side of the equation becomes 0. Thereby, error components caused by both the mechanical angle error of the salient pole and the electrical angle error of the excitation signal can be effectively removed.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment of the position/speed detection device according to the present invention, FIGS. 2 to 4 are diagrams showing an example of the configuration of a detection circuit used in the device of FIG. 1, and FIG. 1 is a diagram showing a configuration example of a conventional position/velocity detection device. 901, 902... Stator member, 903 ₁ ~
903 ₄ , 904 ₁ to 904 ₄ ... Salient pole, 905,
911...Teeth, 907...Stator, 908 ₁ ~
908 ₄ , 909 ₁ to 909 ₄ ... Coil, 910
... Stator, 912 ... Signal source, 913 ... Arithmetic unit.

Claims (1)

[Claims] 1. A first salient pole with teeth formed at a constant pitch at its tip, and teeth whose phase is shifted by 1/2 pitch with respect to the teeth of this first salient pole are formed at its tip. a second salient pole;
a third salient pole having teeth formed at its tip that are out of phase by 1/4 pitch with respect to the teeth of the first salient pole; and a third salient pole with a phase shift of 1/4 pitch with respect to the teeth of the second salient pole. A stator is provided with a fourth salient pole having shifted teeth formed at its tip, and teeth of substantially the same pitch as the teeth of each salient pole provided on this stator are located at a position facing the teeth of each salient pole. The formed rotor is wound around the first salient pole, and as the rotor rotates, the inductance becomes L ₀ {1+m _b sin(θ+
δ _A )} (L ₀ : constant, m _b : constant, θ : phase difference between rotor teeth and first salient pole tooth, δ _A : mechanical angle error of salient pole) 1 coil and the second salient pole, and as the rotor rotates, the inductance becomes L ₀ {1−m _b sin (θ+
δ _A )} is wound around the third salient pole, and as the rotor rotates, the inductance changes to L ₀ {1+m _b cos(θ+
δ _B )} (where δ _B is the error in the mechanical angle of the salient pole), and the third coil is wound around the fourth salient pole, and the inductance changes as the rotor rotates _. {1−m _b cos(θ+
δ _B )}, and the first and second coils are changed to V ₁ cos(ωt+Δ _A ).
(where, V ₁ : amplitude voltage, Δ _A : electrical angle error of AC voltage), the third and fourth coils are excited by V ₁ sin (ωt + Δ _B ) (where Δ _B : AC voltage). a signal source that is excited with an alternating current voltage (error in electrical angle of voltage) and induces voltages V _S1 , V _S2 , V _C1 and V _C2 given by the following equations at both ends of the first to fourth coils, respectively; V _S1 =V ₁ {1+m _b sin(θ+δ _A )} ×cos(ωt+Δ _A ) V _S2 =V ₁ {1−m _b sin(θ+δ _A )} ×cos(ωt+Δ _A ) V _C1 =V ₁ {1+m _b cos (θ + δ _B )} × sin (ωt + Δ _B ) V _C2 = V ₁ {1−m _b cos (θ + δ _B )} × sin (ωt + Δ _B ) For the voltage induced across each coil, V _S1
Perform the calculation −V _S2 +V _C1 −V _C2 , and get V _b = m _b {sin(ωt+θ+δ _A +Δ _A ) +sin(ωt+θ+δ _B +Δ _B )} +2sin{(Δ _B −δ _B −Δ _A +δ _A )/ 2} ×cos{ωt−θ+(Δ _B −δ _B +Δ _A −δ _A )/2} Calculate the calculated value V _b and adjust the electrical angle so that Δ _B −δ _B −Δ _A +δ _A = 0. A position/velocity detection device comprising: an arithmetic unit that adjusts Δ _A and Δ _B and sets the second term of the equation giving the computed value V _b to 0;