JPH01207626A - Position and speed detecting device - Google Patents

Abstract

PURPOSE:To cancel higher harmonics of even order and the rotation of a motor with high accuracy and to improve temperature characteristics by detecting the differences between voltages or currents at both ends of coils wound around projection poles which shift in teeth position by specific pitch. CONSTITUTION:Stator members 901 and 902 are provided with nb (nb: multiple of 2) projection poles 9031-9034 and 9041-9044 where teeth 905 are formed atop at constant pitch, and adjacent projection poles are formed having teeth shifted in phase by pb/2 (pb: pitch of teeth) and wound with coils 9081-9084 and 9091-9094 so that the composite phase of reluctance variation shifts by pb/2. A stator is formed by stacking kb sheets of stator members 901 and 902 so that teeth of adjacent projection poles are out of phase according to equations. A rotor 910 has teeth 901 at the same pitch with and opposite the teeth 905 of the stator. Then a signal source 912 supplies an AC voltage or current signal with a specific phase difference and an arithmetic part 913 detects and processes the currents or voltages at both ends of coils by addition and subtraction to calculate the rotational position and rotating speed.

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, as such a position/velocity detection device, there has been one shown in FIG. 5, for example.

This device uses a motor's stator and rotor core.

It is a multipolar resolver.

In the figure, L, ,L2. L3 is 3 wound around the salient pole of the stator.
Phase coil, 1 has E at one end of coil L+, L2, L3.
A voltage source that applies a voltage s1nωt (E is amplitude, ω is angular velocity, t is time), A1゜A2, A3 is coil L,
, L2. Amplifiers 2 are amplifiers AI and A2 that amplify the potential difference at the other end of L.

3 is a Scotto converter that performs Scotto conversion on the three-phase outputs V^, Va, and Va of A and converts them into two-phase signals; 3 is an R/R/
It is a D converter.

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,=Lc (1+MsJnθ) L2=LC(1+Msin(θ+120>)L3=
Lc (1+M s 1 n (θ-120))Lc
, M: constant In this equation, the inductances of the coils Lt, L2, and L3 are also represented by the same sign.

The voltage source 1 drives each coil by applying a voltage Es1nωt, and the amplifiers A1 to A3 calculate the potential difference V between each coil.
V2. If you take V, it will look like this:

V1=VOsinθs i nωt V2=V(,s i n (θ+120) s i
nωtV co=V(, sin (θ-120)
sin ωtvo: amplitude of pressure When these voltages are subjected to Scotto conversion, signals of sin θslnωt and cos θs 1 nωt are extracted. When these signals are input 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, temperature changes cause an error in the electrical angle of the phase of the output AC signal of the oscillator 22 and the mechanical angle of the salient poles of the stator, resulting in a detection error in the rotation angle θ. There was a problem in that this occurred.

The present invention was made to solve these problems, and an object of the present invention is to realize a position/velocity detection device with good temperature characteristics.

[Means for Solving the Problems] The present invention has nb (nb is a multiple of 2) salient poles in which teeth are not formed at a constant pitch at their tips, and the tooth phase between adjacent salient poles is different. a stator member that is formed with a shift of pb/2 (pb is the tooth pitch), or a coil described below is wound around the salient poles so that the composite phase of reluctance changes is shifted by pb/2 between adjacent salient poles; There are kb stator members, and the tooth phase between adjacent salient poles is: (When an integer) mb is a stator stacked one on top of the other with an integer shift, a rotor that faces the teeth of this stator and has teeth with almost the same pitch as these teeth, and is wound around the same stator member. The coils whose teeth are in the same phase are considered to be one set of coils, and the two sets of coils whose phases are shifted by pb /2 are called one set.
The kb phase coil and each phase coil are 360°/2kb (when kb=2) 360°/
a signal source that provides an alternating current voltage or alternating current signal with a phase difference of kb (when kb is an integer other than 2);
The present invention is characterized by comprising: an arithmetic unit that detects currents or voltages across the coils of each phase, adds and subtracts them, and calculates the rotational position of the rotor from the phase of the addition/subtraction signal and the rotational speed from the frequency. It is a position/speed detection device.

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

FIG. 1 is a configuration diagram of an embodiment of a position/speed detection device according to the present invention, in which (a) is a front view, and (b) is a 2. -2. FIG.

In the figure, 901 and 902 are two disc-shaped stator members made of magnetic material. Stator members 901 and 9
02, there are salient poles 903 at each position separated by a rotation angle of 90'.
1 to 9034 and 9041 to 9044 are formed.

Teeth 905 are formed at the tips of these salient poles at a constant pitch pb.

In the same stator member, the phase of adjacent salient pole teeth is (1
/2) 0 shifted by pb For example, salient pole 903. and 9
The phase of the 032 teeth is shifted by (1/2) pb.

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) They are stacked so that they are shifted by pb 6 For example, the phase of the teeth of salient poles 9031 and 9041 is (1/4) pb
It's off by just that.

9081 is a sudden f! A coil is wound around 903 + and 9033, and 9082 is a coil wound around salient poles 9032 and 9034. 1 by these coils 9081°9082
forming a phase coil. Similarly, coils 9091 and 9092 are wound around the stator member 902.

910 is a rotor placed outside the stators 901 and 902. The rotor 910 is formed with teeth 911 that face the teeth 905 and have substantially the same pitch as the teeth.

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 signal given to coils 908 and 909 has 90@
There is a phase difference of

913 is an arithmetic unit that detects voltages or currents 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 and subtraction signals, and the rotational speed from the frequency.

As a detection circuit for detecting the current or voltage at both ends of the coil, there is a circuit having a configuration not 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 current across the coil, and the circuit shown in FIG. 4 uses a transformer for detection.

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

The signal source 912 has coils 9081 and 9082 with V, c
Applying an AC voltage of os(ωt+Δ^), the coil 909
At 1.9092, an AC voltage of Vl cos (ωt+ΔB +90′″) is applied (V+ is the amplitude voltage, ΔA, ΔB are electrical angle errors).

When the rotor 910 rotates by an angle θ, the coil 90
8+, 9082.909t, 9092 both #At pressure vs 1. vs, , vc, , vc2 are respectively as follows.

vSN2t'(1+'WL4J-4Cθ+Sg'>"<
Qd(A>t+Δ4) (i) "c"-=X
Jl(l-"'4 ov(g0Σ,>'<m(wt+Δ
,) ■mb: Constant・δ^・δB=Mechanical angle error calculation unit 913 detects both of these t@voltages, calculates the formula ■-■formula+■formula-■formula, and calculates the following formula. The calculated value shown
Calculate b.

By adjusting the electrical angle in equation (2) so that ΔB-δB-Δ^+δA=0, the second term on the right side of equation (2) becomes O, 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 different from the numbers shown in the embodiments.

When one stator member is provided with nb salient poles and kb 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 2 ((1/2 kb) 10 mb l ( When kb = 2) ((1/kb) 10mb) (When kb is an integer other than 2) mb: Integer Number of phases of coil: kb Phase difference between each phase of AC voltage or AC current for coil drive : 360"/2kb (when kb = 2) 360'
/kb <when kb is an integer other than 2) In addition, in the embodiment, a case has been described in which the phase of adjacent salient pole teeth of the stator is shifted, but the rotor is not limited to this, and the rotor may have a laminated structure of kb layers, The phases of the teeth in adjacent layers may be shifted as in the case of the adjacent salient poles in the embodiment.

[Effect] According to the device according to the present invention, the tooth position is p b /
Since the difference in voltage or current across the coils wound around two salient poles is detected, even-order harmonics can be canceled out, and the rotation of the motor can be detected with high accuracy.

In addition, since carriers are differentially canceled in the calculation of equation (2), temperature characteristics are improved.

Furthermore, the number of cores, circuits, etc. can be reduced to 2/3 compared to the three-phase position/velocity detection device shown in FIG.

In addition, by making the number of teeth of the motor and the number of teeth of the resolver the same, commutation control can be performed from the phase of the resolver signal.

[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. Conventional position/
It is a diagram showing an example of the configuration of a speed detection device. 901.902... Stator member, 903. ~903
a, 904+~9044... Salient pole, 905°911
... Teeth, 907 ... Stator, 908. ~908a
, 9091 to 9094... Coil, 910... Stator, 912... Signal source, 913... Arithmetic unit. Figure 5

Claims (1)

[Claims] n_b teeth (n_b
is a multiple of 2), and adjacent salient poles are formed by shifting the tooth phase by p_b/2 (p_b is the tooth pitch), or adjacent salient poles are formed by a combination of reluctance changes. A stator member in which a coil (described later) is wound around the salient poles so that the phase is shifted by p_b/2, k_b pieces of this stator member, and the phase of the teeth between adjacent salient poles is expressed as {(1/2k_b)+m_b}p_b ( When k_b=2) {(1/k_b)+m_b}p_b (When k_b is an integer other than 2) m_b is a stator stacked on top of each other with an integer shift, and is opposite to the tooth of this stator and is almost the same as this tooth. A rotor with teeth of the same pitch and a coil wound around the same stator member with teeth in the same phase are considered to be one set of coils, and two sets of coils with a p_b/2 phase shift are called one.
The phase difference between the k_b phase coil and each phase coil is 360°/2k_b (when k_b=2) 360°/k_b (when k_b is an integer other than 2) AC voltage or AC current with a phase difference of 360°/2k_b (when k_b = 2) A signal source that provides a signal; and an arithmetic unit that detects currents or voltages across the coils of each phase, adds and subtracts them, and calculates the rotational position of the rotor from the phase of the added and subtracted signals and the rotational speed from the frequency. A position/velocity detection device characterized by: