JPH05256664A - Magnetic resolver - Google Patents

Abstract

PURPOSE:To reduce the number of wiring arrangements between a resolver part and a driver part by installing a current transformer, performing the addition and subtraction of voltage to be induced by a quadri-phase coil of a resolver, in a resolver part. CONSTITUTION:A current transformer C installed in a resolver part R is provided with four coils 10, 190, 1180, 1270 at the primary side, and these coils are connected in a series to those of 0 deg. phase coil L0, 90 deg. phase coil L90, 180 deg. phase coil L180, 270 deg. phase coil L270. In addition, when currents I0, R90, I180, I270 flow into these coils 10, 190, 1180, 1270 by each generated voltage of two signal sources 41, 42, each coil detects these currents. On the basis of the voltage induced by the detected current, the transformer C performs operation with a specified expression, inducing a voltage signal Vs in the detected coil L1. This voltage signal Vs sought like this is fed to a driver part D by a distribution cable, and at this driver part D, a phase difference between the signal Vs and an output V0cosomega t of the signal source 42 is taken out, through which a turning angle theta is found out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to reducing the wiring of a magnetic resolver.

[0002]

2. Description of the Related Art Conventionally, a magnetic resolver using a four-phase coil has, for example, a structure shown in FIG. This figure shows the mechanical structure. This magnetic resolver comprises a resolver section R and a driver section D. In the resolver portion R, reference numeral 1 is a rotor having a cylindrical shape and teeth 2 formed on the inner circumference at a constant pitch p. The rotor 1 rotates together with the detection target. Reference numeral 3 is a stator arranged inside the rotor 1. Both the rotor 1 and the stator 3 are made of a magnetic material. In the stator 3, 4n (n is an integer), for example, 16
Individual salient poles 31 _{1 to} 31 ₁₆ are formed. Teeth 4 having a pitch p facing the teeth 2 are formed at the tips of these salient poles. The phases of the teeth formed on the salient poles are shifted by p / 4 according to the arrangement order of the salient poles. For example, the teeth of the salient poles 31 ₂ , 31 ₃ , and 31 ₄ are out of phase with the teeth of the salient pole 31 ₁ by p / 4, p / 2, and 3p / 4, respectively. Salient pole 3
1 ₁ , 31 ₂ , 31 ₃ , 31 ₄ are 0 ° salient pole, 90 °
Salient pole, 180 ° salient pole and 270 ° salient pole. Hereinafter, the salient poles repeat the same arrangement. Reference numerals 32 _{1 to} 32 ₁₆ are coils wound on salient poles 31 _{1 to} 31 ₁₆ , respectively. 0 °
The coils wound around salient poles, 90 ° salient poles, 180 ° salient poles, and 270 ° salient poles are 0 ° phase coil, 90 ° phase coil,
180 ° phase coil and 270 ° phase coil. In the driver section D, 4 is a signal source that excites the coil wound around each salient pole with an AC voltage, and 5 is an arithmetic circuit that calculates the rotational position of the motor from the induced voltage of each coil.

FIG. 4 is an electric circuit diagram of the magnetic resolver of FIG.
is there. 4 that are the same as those in FIG. 3 are assigned the same reference numerals. Since
The same applies to the figures below. In FIG. 4, L₀，
L₉₀, L₁₈₀, L₂₇₀Is each salient pole of the magnetic resolver shown in FIG.
Between multiple 0 ° phase coils and 90 ° phase coils
180 ° phase coils, 270 ° phase coils
Are coils connected in series. Brief description
Coil L₀, L₉₀, L₁₈₀, L₂₇₀Each
0 ° phase coil, 90 ° phase coil, 180 ° phase coil, 2
It is called a 70 ° phase coil. 41 is a 0 ° phase coil and 180
° V phase coil₀sinωt (V₀Is the amplitude of the voltage, ω is the angle
A signal source that is excited by an AC voltage of speed, t is time, 42
Is a 90 ° phase coil and a 270 ° phase coil₀cosωt
It is a signal source that is excited by an alternating voltage. 51 is a coil L
₀And L₁₈₀Voltage V generated by the current flowing in the₁And V₂of
Subtractor for taking the difference, 52 is a coil L₉₀And L₂₇₀Electricity flowing through
Voltage V generated by the current₃And V _FourIs a subtractor that takes the difference of
It 53 is an adder for adding the outputs of the subtracters 51 and 52
is there. In such a magnetic resolver, the rotor is
When rotated by θ, voltage V₁~ V_FourIs as follows
It V₁= K (1 + msin nθ) sin ωt V₂= K {1 + msin (nθ + 180 °)} sinω
t = K (1-mssin θ) sinωt V₃= K {1 + msin (nθ + 90 °)} cosωt
= K (1 + mcosnθ) cosωt V_Four= K {1 + msin (nθ + 270 °)} cosω
t = K (1-mcosnθ) cosωt K: constant, m: constant (m << 1), n: number of rotor teeth Subtractors 51, 52 and adder 53 have₁~ V_FourAbout
The next addition and subtraction is performed. V₁-V₂+ V₃-V_Four = 2m (sinnθsinωt + cosnθcosω
t) = 2mcos (ωt−nθ) and the signal 2mcos (ωt−nθ) thus obtained
Output V of signal source 42₀to take the phase difference of cosωt
Then, the rotation angle θ is obtained.

In such a magnetic resolver, the number of wires between the resolver section and the driver section is eight, as shown in FIG. When a magnetic resolver is used in a robot having a plurality of built-in motors, the number of wires should be as small as possible. This is because the wiring cables are routed along with the operation of the robot, and therefore it is necessary to reduce the number of wiring cables as much as possible in order to reduce the disconnection rate.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in order to solve such problems, and an object thereof is to realize a magnetic resolver in which the number of wires between the resolver section and the driver section is reduced. And

[0006]

SUMMARY OF THE INVENTION The present invention is a magnetic resolver for magnetically detecting the rotational position of an object to be detected, comprising a resolver section and a driver section interconnected by a cable, and the resolver section is provided at the tip. It is composed of a plurality of salient poles with teeth formed at a pitch p, and these salient poles have 0 ° salient poles, 90 ° salient poles with different tooth phases by p / 4 pitch,
A salient pole group consisting of a 0 ° salient pole and a 270 ° salient pole;
Salient pole, 90 ° salient pole, 180 ° salient pole, 270 ° salient pole wound 0 ° phase coil, 90 ° phase coil, 180 °
Phase coil, 270 ° phase coil, and a first coil, a second coil, and a first coil connected in series to the 0 ° phase coil, 90 ° phase coil, 180 ° phase coil, and 270 ° phase coil on the primary side, respectively. The third coil and the fourth coil are provided, and the detection coil is provided on the secondary side. The winding directions of the first coil and the second coil are the same, and the third coil and the fourth coil are provided.
Has a current transformer whose winding direction is opposite to the winding directions of the first coil and the second coil, and the driver section generates a sin-phase AC voltage and a cos-phase AC voltage. Then, the 0 ° phase coil and the 180 ° phase coil are excited by one alternating voltage, and the 90 ° phase coil and the 270 ° phase coil are excited by the other alternating voltage. When the ° phase coil, the 90 ° phase coil, the 180 ° phase coil, and the 270 ° phase coil are excited, the current transformer causes the currents flowing in these coils to flow through the first coil, the second coil, and the third coil. Fourth
Is detected by the coil of (1), and based on the voltage induced by the detected current, (the induced voltage of the 0 ° phase coil)-(the induced voltage of the 180 ° phase coil) + (the induced voltage of the 90 ° phase coil)-(270 °
The magnetic resolver is characterized in that a voltage signal whose phase is modulated according to the rotational position of the detection target is induced in the secondary detection coil by performing the following calculation.

[0007]

According to the present invention as described above, the current transformer provided in the resolver unit adds and subtracts the voltage induced in the four-phase coil of the resolver to calculate the voltage signal whose phase is modulated according to the rotational position of the detection target. To do.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. Figure 1
FIG. 1 is a configuration diagram showing an embodiment of the present invention. In FIG. 1, the resolver section R is provided with a current transformer C. The current transformer C has a coil l ₀ ,
l ₉₀ , l ₁₈₀ , l ₂₇₀ are provided. Coils l ₀ , l
₉₀ , l ₁₈₀ , l ₂₇₀ are 0 ° phase coil L ₀ , 90 ° phase coil L ₉₀ , 180 ° phase coil L ₁₈₀ , 270 ° phase coil L
It is connected in series with the ₂₇₀ . The coils l ₀ and l ₉₀ are wound in the same direction, and the coils l ₁₈₀ and l ₂₇₀ are wound in the opposite direction to the coils l ₀ and l ₉₀ . Also, 2
A detection coil L ₁ is provided on the next side.

In such a magnetic resolver, the signal source
The voltage generated by 41 and 42 causes the coil 1 to₀, L₉₀, L₁₈₀，
l₂₇₀Current I₀, I₉₀, I₁₈₀, I₂₇₀When it flows, carp
L ₀, L₉₀, L₁₈₀, L₂₇₀Is the current flowing through each coil
To detect. And the voltage induced by the detected current
In addition, the current transformer C calculates the following equation and detects
Le L₁Voltage V_sInduce. V_s= K₁(I₀-I₁₈₀＋ I₉₀-I₂₇₀) = K₁{V₀sin ωt / ωL₀(1 + msin nθ)-
V₀sin ωt / ωL₀(1-mssin θ) + V₀co
sωt / ωL₀(1 + mcosnθ) -V₀cosωt /
ωL₀(1-mcosnθ)} = (K₁V₀/ ΩL₀) {Sin ωt / (1 + msinn
θ) -sinωt / (1-mssinθ) + cosωt
/ (1 + mcosnθ) -cosωt / (1-mcos
nθ)} =-(2 mK₁V₀/ ΩL₀) × {sinωtsinnθ
/ (1-m²sin²nθ) + cosωtcos nθ /
(1-m²cos²nθ)} K₁, L₀: Constant where m << 1, m²sin²nθ << 1, m²cos²
nθ << 1 and the voltage V_sIs as follows: V_s=-(2mK₁V₀/ ΩL₀) × (sin ωtsinn
θ + cosωtcos nθ) = − (2mK₁V₀/ ΩL₀) Cos (ωt−nθ) The signal V thus obtained_sIs a wiring cable
The signal is sent to the driver section D and the signal V is sent to the driver section D._sAnd signal
Output V of source 42₀By taking the phase difference of cosωt
Determine the rotation angle θ.

FIG. 2 is a block diagram of another embodiment of the present invention. In this magnetic resolver, an absolute position detecting resolver is configured by combining a 1X resolver R ₁ and an nX resolver R _n . Here, the rotor of the 1X resolver R ₁ is 1
The phase of the detection signal V _s1 changes 360 ° each time the rotor rotates, and the phase of the detection signal V _sn changes 360 ° each time the rotor rotates 1 / n (n is the number of teeth of the rotor) in the nX resolver R _n . To do. When the rotor makes one revolution, the cycle of the detection signal V _sn of the nX resolver R _n changes n times. Therefore, 1
The number of cycles of the detection signal of the nX resolver is detected by the magnitude of the detection signal V _s1 of the X resolver R ₁ , and the rotational position within the detected cycle is detected from the magnitude of the detection signal V _sn of the nX resolver. To do. With this, the absolute rotational position is detected.

[0011]

According to the present invention, addition / subtraction of the induced voltage of the coil is performed by the current transformer provided in the resolver section. Therefore, a wiring cable for transmitting the induced voltage of the coil from the resolver section to the driver section is unnecessary.
This can reduce the number of wiring cables between the resolver section and the driver section. The conventional example of FIG. 4 requires eight wiring cables, whereas the embodiment of the present invention of FIG. 1 can reduce the number of wiring cables to six. Moreover, since addition and subtraction are performed by one current transformer, the circuit configuration is simplified as compared with the conventional example of FIG.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the present invention.

FIG. 3 is a mechanical configuration diagram of a conventional magnetic resolver.

FIG. 4 is an electric circuit diagram of a conventional magnetic resolver.

[Explanation of symbols]

R: Resolver part D: Driver part L ₀ 0 ° phase coil L ₉₀ , 90 ° phase coil L ₁₈₀ 180 ° phase coil L ₂₇₀ 270 ° phase coil C Current transformer l ₀ First coil l ₉₀ Second coil l ₁₈₀ Third coil 1 ₂₇₀ Fourth coil L ₁ Detection coil 31 _{1 to} 31 ₁₆ Salient pole 4 Teeth 41, 42 Signal source

Claims (1)

[Claims] 1. A magnetic resolver for magnetically detecting a rotational position of a detection target, comprising a resolver section and a driver section interconnected by a cable, wherein the resolver section has teeth formed at a pitch p at a tip thereof. It consists of multiple salient poles,
These salient poles have tooth phases that differ by p / 4 pitch at 0 °
A salient pole group consisting of salient poles, 90 ° salient poles, 180 ° salient poles and 270 ° salient poles, and 0 wound on the 0 ° salient poles, 90 ° salient poles, 180 ° salient poles and 270 ° salient poles, respectively. ° phase coil, 90 ° phase coil,
180 ° phase coil, 270 ° phase coil, and 0 ° phase coil, 90 ° phase coil, 180 ° on the primary side
The first coil, the second coil, the third coil, and the fourth coil, which are respectively connected in series to the phase coil and the 270 ° phase coil, are provided, and the detection coil is provided on the secondary side. The winding directions of the first coil and the second coil are the same,
The winding direction of the third coil and the fourth coil has a current transformer that is opposite to the winding direction of the first coil and the second coil, and the driver section is a sin phase AC voltage. a signal source for generating a cos phase alternating voltage, exciting the 0 ° phase coil and the 180 ° phase coil with one alternating voltage, and exciting the 90 ° phase coil and the 270 ° phase coil with the other alternating voltage. The 0 ° phase coil, 90 ° phase coil, 18
When the 0 ° -phase coil and the 270 ° -phase coil are excited, the current transformer causes the current flowing in these coils to be the first
Of the coil, the second coil, the third coil, and the fourth coil, and based on the voltage induced by the detected current, (induction voltage of 0 ° phase coil) − (induction of 180 ° phase coil) Voltage) + (induced voltage of 90 ° phase coil) − (270 °
The induced voltage of the phase coil) is calculated, and a voltage signal whose phase is modulated according to the rotational position of the detection target is induced in the detection coil on the secondary side.