JPH11118416A - Vr type angle detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate an error component to improve the precision by providing a structure that the form of a rotor has a stator-to-rotor gap represented by a specified expression. SOLUTION: A form of a rotor is constituted to have a stator-to-rotor gap by adding a correction item as shown in the expression. In the expression, δ(θ) : the stator-to-rotor gap at a rotating angle θ, δ0 : the stator-to-rotor gap in 90 deg. and 270 deg. positions, δ1 : the stator-to-rotor gap in 0 deg.-position, (n): 1, and K: a constant. A simulation is performed so that an output signal 10 containing an error component C which is the difference between an output voltage measured value A determined by measurement and a theoretical value B which is an ideal output voltage is an output signal 10A containing a correction signal Aa obtained by correcting the error component C and a reverse error signal component Ca obtained by reversing the error signal C, and the correction quantity of the value of K in the expression is determined. Thus, the correction signal Aa is a highly precisely resolver output signal approximate to the theoretical value B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a VR angle detector, and more particularly, to a method of changing a rotor shape from a conventional shape by adding a correction term to a formula indicating the rotor shape, thereby producing an error component which has been generated in the past. And to a new improvement for improving accuracy by eliminating.

[0002]

2. Description of the Related Art A well-known V of this kind which has been used in the past
As an R (variable reluctance) type angle detector,
As shown in FIG. 2, a non-circular rotor 2 is rotatably provided inside the stator 1, and the shape of the rotor 2 is formed by the following equation (1).

[0003]

(Equation 2)

Accordingly, the shape of the rotor 2 is substantially heart-shaped.

[0005]

The conventional VR type angle detector has the following problems because it is configured as described above. That is, in the conventional configuration, as shown in FIG. 3, primary and tertiary error components are generated in both the COS output and the SIN output, and the primary and tertiary error components are added to the output voltage as the resolver angle signal. A waveform state indicated by the symbol θ _OUT of No. 3 is obtained. The reason for this is that when calculating equation (1), it is assumed that the magnetic flux travels linearly in the gap toward the center of the rotor as shown in FIGS. 5 and 7, the magnetic flux advances in a curved portion as shown in FIGS. 5 and 7, and the length of the magnetic path is different from that at the time of linear approximation. That is, it is due to the influence of the leakage magnetic flux on the end face of the rotor. For this reason, when a rotor having a conventional shape is used, it is difficult to improve the accuracy by including the above-described error.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. In particular, the shape of the rotor is changed from the conventional shape by adding a correction term to the equation indicating the shape of the rotor, and the conventional method is employed. It is an object of the present invention to provide a VR-type angle detector which eliminates an error component and improves accuracy.

[0007]

A VR type angle detector according to the present invention rotates a rotor composed of a non-circular core with respect to a stator, and changes a gap permeance at a rotation angle θ in proportion to a SIN function. In the VR type angle detector having the shape of the rotor as described above, the shape of the rotor has a gap between the stator and the rotor according to the following equation (2).

[0008]

(Equation 3)

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
A preferred embodiment of the R-shaped angle detector will be described.
The same or equivalent parts as those in the conventional example will be described using the same reference numerals. Stator 1 and rotor 2 in the present embodiment
2 is the same as the configuration of FIG. 2 described in the conventional example, the description is omitted here, and the specification of the shape of the rotor 2 for eliminating (cancelling) an error will be described below. That is, as shown in FIG. 1, as shown in the following equation (2), the correction term [K +
(1-COS2θ)]. That is, the actual measured output voltage A obtained by the actual measurement and the theoretical value B which is the ideal output voltage.
Simulation is performed so that the output signal 10 including the error component C, which is the difference between the output signal 10A and the correction signal Aa obtained by correcting the error component C, and the output signal 10A including the inverted error component Ca obtained by inverting the error signal C, The correction amount based on the value of K in the equation (2) is determined. This constant K is a constant taking a value of + and-, and the value differs depending on the correction amount of this simulation.
Therefore, as shown in FIG. 1, since the error component C is inverted and used as Ca, the correction signal Aa, which is a combined component, can obtain a higher-precision resolver output signal that is closer to the theoretical value B than in the related art. . The present invention can be applied not only to the resolver but also to other angle and speed detectors.

[0010]

The VR resolver according to the present invention is configured as described above, so that the following effects can be obtained. That is, since the rotor shape is formed by a new formula by adding a correction term to the formula indicating the conventional rotor shape, the first-order and third-order error components included in the conventional output signal are canceled, and the accuracy is reduced. Can be improved.

[Brief description of the drawings]

FIG. 1 is a waveform diagram showing a correction state of a resolver output signal of a VR angle detector according to the present invention.

FIG. 2 is a configuration diagram showing a VR type angle detector according to the present invention and a conventional VR angle detector.

FIG. 3 is a characteristic diagram showing output characteristics of a conventional VR type angle detector.

FIG. 4 is an explanatory diagram showing a conventional magnetic flux generation state.

FIG. 5 is an explanatory diagram showing a conventional magnetic flux generation state.

FIG. 6 is an explanatory sectional view of FIG. 4;

FIG. 7 is an explanatory sectional view of FIG. 5;

[Explanation of symbols]

 1 stator 2 rotor

Claims (1)

[Claims] 1. A rotor (2) comprising a non-circular core is rotated with respect to a stator (1), and said rotor (2) is changed so that a gap permeance changes in proportion to a SIN function at a rotation angle θ. Wherein the shape of the rotor (2) has a gap between the stator (1) and the rotor (2) according to the following equation (2). VR type angle detector. (Equation 1)