JPH0648201B2 - Position / speed detector - Google Patents

Description

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

[Prior Art] Conventionally, as a position / speed detecting device using a magnetic resolver, for example, there has been one using a two-phase excitation resolver phase shifter shown in FIG.

In the figure, S _{1 to} S ₄ are primary coils provided on the stator side, E ₁ and E ₂ are signal sources for driving the coils S ₁ , S ₃ and S ₂ , S ₄ , and S ₀ is a rotor side. It is a secondary coil provided.

In such a device, the signal sources E ₁ and E ₂ generate the coils S ₁ , S ₃ with an AC voltage (V is the amplitude of the AC voltage, ω is the angular velocity, t is the time) of Vsinωt and Vcosωt.
When S ₂ and S ₄ are driven, the following voltage E ₀ is generated in the secondary coil S ₀ .

E ₀ = K ₀ (Vsinωtcosθ + Vcosωtsinθ) = K ₀ Vsin (ωt + θ) K ₀ : Change ratio, θ: Rotation angle of rotor As shown in this equation, the rotation angle θ of the rotor in the secondary coil
Voltages which are out of phase with each other are detected.

[Problems to be Solved by the Invention] However, since the voltage detected by the secondary coil in this way contains harmonic components, the detection waveform of the detection signal contains many errors and the angle detection is performed. There was a problem that the linearity of was poor.

The present invention has been made in order to solve such a problem, and an object of the present invention is to realize a position / speed detection device that has few harmonic components included in an angle detection signal and has good linearity of angle detection. And

[Means for Solving the Problems] According to the present invention, a rotor having teeth formed at a pitch Pγ and salient poles that are multiples of M (M is an integer) are formed. The pitch is (Pγ / kns) ns facing the rotor teeth, ns: the number of teeth in the salient pole k: a multiple of 3 when M is an even number, and an even number when M is a multiple of 3 And a stator in which the teeth of adjacent salient poles are out of phase with each other by Pγ / M, and an M-phase coil in which a coil wound around a salient pole with teeth of the same phase is one phase , Two rotors and two stators are provided, the rotor teeth are stacked in the same phase, and the stator teeth are stacked by shifting the phase by Pγ / 4, and The coil of each stator has Vcosωt and Vsinωt Position / velocity detection provided with a signal source for providing an AC voltage, and an arithmetic unit for adding / subtracting the voltages across the coils of the respective phases and calculating the rotational position of the rotor from the phase of the addition / subtraction signal and the rotational speed from the frequency. It is a device.

[Examples] The present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of an embodiment of a position / speed detection device according to the present invention, (a) is a plan view, and (b) is a cross-sectional view taken along the line XX in (a).

In the figure, reference numeral 1 denotes a rotor having a cylindrical shape and teeth 2 having a constant pitch Pγ formed on the inner periphery thereof, and two rotors 1 ₁ and 1 ₂ are provided in an overlapping manner.

Reference numeral 3 denotes a stator arranged inside the rotor 1. The stator 3 has 4N (N is an integer), for example, 16 salient poles 4 ₁
To 4 ₁₆ is provided. Teeth 5 facing the teeth 2 are provided at the tips of these salient poles. The coil _{61 through 16} are wound on each salient pole. In the figure, only the coil 6 ₁ wound around the salient pole 4 ₁ is shown.

_Two such stators 3 ₁ and 3 ₂ are insulating members 7
Are provided so as to overlap each other.

The rotor 1 and the stator 3 are formed by laminating steel plates.

8 ₁ and 8 ₂ are coils of the stators 3 ₁ and 3 ₂ , and Ec = V
It is a signal source that gives an alternating voltage (V is a voltage amplitude) such that cos ωt and Es = Vsin ωt.

The detailed structure of the rotor and the stator is shown in FIG.

This figure is an exploded view of the rotor and the stator.

In the figure, ns teeth are formed in one salient pole (ns = 4 in the case of the figure). In addition, salient poles 4 ₁ , 4 ₂ ,
The phases of 4 ₃ and 4 ₄ are shifted from the teeth 2 of the rotor 1 by 0, (1/4) Pγ, (2/4) Pγ, and (3/4) Pγ, respectively.

A total of 16 salient poles are provided, and four salient poles of each phase are provided. Then, one phase is formed by the coils wound on the salient poles having the same phase.

The coils wound on the salient poles having a phase shift of 0, (1/4) Pγ, (2/4) Pγ, (3/4) Pγ are referred to as A-phase, B-phase, C-phase, and D-phase coils, respectively. To do.
The pitch Ps of the teeth 5 of the salient poles is Ps = Pγ− (Pγ / 3ns). As a result, the teeth 5 of the salient poles are shifted in phase by Pγ / 3 ns according to the arrangement direction. Therefore, the tooth 5 can be used as a vernier.

Rotor 1 ₁ and 1 ₂ are superposed with a phase of the teeth 2 in the same phase. The stators 3 ₁ and 3 ₂ are overlapped with each other by shifting the phase of the tooth 5 by Pγ / 4.

The coils of the stator are connected as shown in FIG.

In FIG. 3, L ₁ is a coil in which A-phase and B-phase coils are connected in series, and L ₂ is a coil in which C-phase and D-phase coils are connected in series. These coils have Vcosω in the stator 3 ₁ .
t is, the stator _{3, 2} Vsinomegati becomes voltage is applied.

Then, the voltage generated in the coil is detected via the resistor, the amplifier and the subtractor.

Next, the operation of such a device will be described.

The voltages s ₁ , s ₂ , s ₃ , and s ₄ generated in the A-phase, B-phase, C-phase, and D-phase coils are as follows.

l: order of teeth, E: amplitude voltage m ₁ , m ₂ , ... M _n : constant voltage s ₁ + s ₂ −s ₃ −s _{4 obtained} by adding or subtracting these voltages is as follows.

From the formula, the 2n _1st- order and 3n _2nd- order (n ₁ and n ₂ are integers) harmonic components are removed. The fifth and higher harmonics have little effect and can be ignored. Therefore, the detected voltage is as follows.

s ₁ + s ₂ −s ₃ −s ₄ = A ₀ sin (θ +) where A ₀ is a constant and is an initial phase. Equivalent to.

FIG. 4 shows a vector diagram of each voltage s _{1 to} s ₄ . As shown in this figure, the combined vector of the voltages s ₁ and s ₂ and the voltage s
_The second harmonic component is eliminated by taking the difference between the combined vector of ₃ and s ₄ , and the tooth provided on the salient pole is used as a vernier to eliminate the third harmonic component.

Accordingly, the voltage detected by the stator 3 ₁ becomes Vs = Ec (s ₁ + s ₂ −s ₃ −s ₄ ) = Vcosωt · Asin (θ +). The detection signals vs ₁ and vs ₂ in FIG. ₃ correspond to s ₁ + s ₂ and s ₃ + s ₄ , respectively.

Also, the voltage detected by the stator _{3 2} becomes _{Vs = Es (s 1 + s} 2 -s 3 -s 4) = Vsinωt · Acos (θ +). The detection signals vc ₁ and vc ₂ in FIG. ₃ correspond to s ₁ + s ₂ and s ₃ + s ₄ .

From this, the signal detected by the circuit of FIG. 3 _{is, V T = Vs-Vc =} Vcosωt · Asin (θ +) -Vsinωt · Acos (θ +) = AVsin (θ + -ωt) , and the rotation angle of the rotor theta The phase of the detection signal is modulated by. Therefore, the rotation angle can be detected by reading this phase.

In addition, although the case where the four-phase coil is used has been described in the embodiment, the number of phases of the coil may be other than this. Eg 3
When a phase coil is used, the phase of the teeth of the adjacent salient poles is shifted by Pγ / 3 with respect to the teeth of the rotor to remove the third harmonic component, and the teeth of the salient poles with respect to the pitch of the rotor. Pγ / 2
The vernier structure shifted by ns is used to remove the second harmonic component.

Further, in the embodiment, s ₁ + s is applied to both the stators 3 ₁ and 3 _{2.
Although the case where the 2-} s ₃ -s ₄ signal is detected and the harmonic component is removed has been described, the harmonic component may be removed by addition or subtraction other than this. For example, in the stator 3 ₁ , s ₁ +
s harmonic components were removed ₂ -s ₃ -s _4, the stator _{3 2}
Then, the harmonics may be removed by s ₂ + s ₃ −s ₄ −s ₁ . In this case, the stator 3 _2, with the coils of the B-phase and C-phase are connected in series, the coils of the A-phase and D-phase are connected in series.

Further, the tooth pitch of the salient pole is not limited to Pγ- (Pγ / 3ns) and may be Pγ + (Pγ / 3ns).

Further, the teeth of the stator 3 ₂ salient poles may be teeth and the same phase of the stator 3 ₁ of salient poles.

[Effect] According to the present invention, the multi-phase coil and the teeth of the salient poles that are vernier with respect to the teeth of the stator are used to remove the second harmonic and the third harmonic generated in the detection voltage of the coil. Therefore, the error of the detection signal is reduced and the linearity of the angle detection is improved.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a position / speed detecting device according to the present invention, FIG. 2 is a block diagram of a main part of FIG. 1, and FIG. 3 is a detection circuit of the device of FIG. FIG. 4 is a vector diagram of the coil voltage of the device of FIG. 1, and FIG. 5 is a diagram showing a configuration example of a conventional position / speed detecting device. 1,1 _{1, 1 2} ...... rotor, 2,5 ...... teeth, _3,3 1,
3 ₂ ... Stator, 4 ₁ to 4 ₁₆ ... Salient pole, 6 ... Coil, 8 ₁ , 8 ₂ ... Signal source.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Ritaro Sano 2-9-32 Nakamachi, Musashino City, Tokyo Yokogawa Electric Co., Ltd. (56) Reference JP 62-144018 (JP, A) JP Sho 62-144017 (JP, A) Actually developed 57-92108 (JP, U)

Claims (1)

[Claims] 1. A rotor having teeth formed at a pitch Pγ and salient poles that are multiples of M (M is an integer) are formed, and the tips of the salient poles face the teeth of the rotor. Pitch is (Pγ / kns) ns: Number of teeth in salient pole k: Multiple of 3 when M is an even number When M is a multiple of 3 Even number of teeth different from the rotor teeth are provided and they are adjacent to each other The salient poles are composed of a stator whose teeth are out of phase with each other by Pγ / M, and an M-phase coil whose one phase is a coil wound around a salient pole having teeth of the same phase. Two stators are provided, the teeth of the rotor are stacked in the same phase, the teeth of the stator are stacked by shifting the phase by Pγ / 4, and the core parts are stacked by Vcosωt. And a signal source that gives an AC voltage of Vsinωt, A position / speed detection device comprising: a calculation unit that adds / subtracts the voltage across the coils of each phase and calculates the rotational position of the rotor from the phase of the addition / subtraction signal and the rotational speed from the frequency.