Sensing apparatus for detecting intensity of an external magnetic field and compensating for an amount of change of a sensor output
An embodiment discloses a sensing apparatus comprising: a rotor; a stator disposed corresponding to the rotor; a first collector disposed on one surface of the stator; and a second collector disposed below the first collector. The stator includes a stator tooth that includes a body and a tooth, the first collector includes a first body and a first leg, the second collector includes a second body and a second leg, the first body and the second body are separable from each other, the body of the stator tooth is located between the first body and the second body, and the first leg and the second leg do not overlap each other in an axial direction. Accordingly, the plurality of collectors, which are disposed so that the magnetic resistances are differently formed, compensate for changes in output value due to external magnetism, thus making it possible for the sensing apparatus to achieve sufficient performance.
1 . A sensing apparatus comprising:
a rotor;
a stator disposed corresponding to the rotor;
a first collector disposed on one surface of the stator;
a second collector disposed below the first collector;
a first sensor disposed corresponding to the first collector, and
a second sensor disposed corresponding to the second collector,
wherein the stator includes a stator tooth that includes a body and a tooth,
the first collector includes a first body and a first leg,
the second collector includes a second body and a second leg,
the first body and the second body are separated from each other,
the body of the stator tooth is disposed between the first body and the second body, and
the first leg and the second leg do not overlap each other in an axial direction,
a sensing value of at least one of the first sensor and the second sensor is corrected based on a difference value between a sensing value of the first sensor and a sensing value of the second sensor,
the sensing value of the first sensor is compensated with a compensation value calculated by Equation 1 below,
T
1
c
=
T
1
o
-
a
*
(
T
2
o
-
T
1
o
)
[
Equation
1
]
here, T1c is a compensated sensing value of the first sensor, T1o is an uncompensated sensing value of the first sensor, T2o is an uncompensated sensing value of the second sensor, and a is a compensation factor corresponding to an axial spaced distance between the first collector and the second collector.
2 . The sensing apparatus of claim 1 , wherein the first leg includes a first extension portion extending from the first body in a radial direction, a first bent portion extending from the first extension portion in the axial direction, and a first facing portion extending from the first bent portion, and
the second leg includes a second extension portion extending from the second body in the radial direction, a second bent portion extending from the second extension portion in the axial direction, and a second facing portion extending from the second bent portion,
wherein an axial length (L1) of the first bent portion is greater than an axial length (L2) of the second bent portion.
3 . The sensing apparatus of claim 2 ,
wherein the first sensor is disposed to face the first facing portion and the second sensor is disposed to face the second facing portion.
4 . The sensing apparatus of claim 1 , wherein the first body and the second body are disposed to overlap each other in the axial direction.
5 . The sensing apparatus of claim 1 , wherein an area of the first body is different from an area of the second body.
6 . The sensing apparatus of claim 1 , wherein a first gap (G1) is formed between the body of the stator tooth and the first body and a second gap (G2) is formed between the body of the stator tooth and the second body,
wherein the first gap (G1) is greater than the second gap (G2).
7 . The sensing apparatus of claim 1 , wherein the sensing value of the second sensor is compensated with a compensation value calculated by Equation 2 below,
T
2
c
=
T
2
o
-
b
*
(
T
2
o
-
T
1
o
)
[
Equation
2
]
here, T2c is a compensated sensing value of the second sensor, T1o is the uncompensated sensing value of the first sensor, T2o is the uncompensated sensing value of the second sensor, and b is a compensation factor corresponding to the axial spaced distance between the first collector and the second collector.
8 . The sensing apparatus of claim 1 , wherein the stator tooth includes a first stator tooth and a second stator tooth,
the first stator tooth includes a first tooth body and a first tooth, and
the first tooth body is disposed between the first body and the second body.
9 . The sensing apparatus of claim 8 , further comprising a third collector and a fourth collector disposed corresponding to the second stator tooth, and
wherein the second tooth body of the second stator tooth is disposed between a third body of the third collector and a fourth body of the fourth collector.
10 . A sensing apparatus comprising:
a rotor;
a stator disposed corresponding to the rotor;
a first collector disposed on one surface of the stator;
a second collector disposed below the first collector;
a first sensor disposed corresponding to the first collector; and
a second sensor disposed corresponding to the second collector,
wherein the stator includes a first stator tooth and a second stator tooth that include a body and a tooth,
the first collector includes a first body and a first leg,
the second collector includes a second body and a second leg,
the first body and the second body are separated from each other,
the first body is disposed on an upper side of the body of the first stator tooth,
the second body is disposed between the body of the first stator tooth and the body of the second stator tooth, and
the first body and the second body are disposed to overlap each other in an axial direction,
a sensing value of at least one of the first sensor and the second sensor is corrected based on a difference value between a sensing value of the first sensor and a sensing value of the second sensor,
the sensing value of the first sensor is compensated with a compensation value calculated by Equation 1 below,
T
1
c
=
T
1
o
-
a
*
(
T
2
o
-
T
1
o
)
[
Equation
1
]
here, T1c is a compensated sensing value of the first sensor, T1o is an uncompensated sensing value of the first sensor, T2o is an uncompensated sensing value of the second sensor, and a is a compensation factor corresponding to an axial spaced distance between the first collector and the second collector.
11 . The sensing apparatus of claim 10 , wherein the first leg includes a first extension portion extending from the first body in a radial direction, a first bent portion extending from the first extension portion in the axial direction, and a first facing portion extending from the first bent portion, and
the second leg includes a second extension portion extending from the second body in the radial direction, a second bent portion extending from the second extension portion in the axial direction, and a second facing portion extending from the second bent portion,
wherein an axial length (L1) of the first bent portion is greater than an axial length (L2) of the second bent portion.
12 . A sensing apparatus comprising:
a rotor;
a stator disposed corresponding to the rotor;
a first collector disposed on one surface of the stator;
a second collector disposed below the first collector;
a first sensor disposed corresponding to the first collector; and
a second sensor disposed corresponding to the second collector,
wherein the stator includes a first stator tooth and a second stator tooth that include a body and a tooth,
the first collector includes a first body and a first leg,
the second collector includes a second body and a second leg,
the first body and the second body are separated,
the body of the stator tooth is disposed between the first body and the second body, and
an axial height (H1) of the first leg is greater than an axial height (H2) of the second leg,
a sensing value of at least one of the first sensor and the second sensor is corrected based on a difference value between a sensing value of the first sensor and a sensing value of the second sensor,
the sensing value of the first sensor is compensated with a compensation value calculated by Equation 1 below,
T
1
c
=
T
1
o
-
a
*
(
T
2
o
-
T
1
o
)
[
Equation
1
]
here, T1c is a compensated sensing value of the first sensor, T1o is an uncompensated sensing value of the first sensor, T2o is an uncompensated sensing value of the second sensor, and a is a compensation factor corresponding to an axial spaced distance between the first collector and the second collector.
13 . The sensing apparatus of claim 12 , wherein the first leg includes a first extension portion extending from the first body in a radial direction, a first bent portion extending from the first extension portion in the axial direction, and a first facing portion extending from the first bent portion, and
the second leg includes a second extension portion extending from the second body in the radial direction, a second bent portion extending from the second extension portion in the axial direction, and a second facing portion extending from the second bent portion,
wherein an axial length (L1) of the first bent portion is greater than an axial length (L2) of the second bent portion.
14 . The sensing apparatus of claim 12 , wherein the first body and the second body are disposed to overlap each other in the axial direction.
15 . The sensing apparatus of claim 12 , wherein an area of the first body is different from an area of the second body.
16 . The sensing apparatus of claim 12 , wherein a first gap (G1) is formed between the body of the stator tooth and the first body and a second gap (G2) is formed between the body of the stator tooth and the second body,
wherein the first gap (G1) is greater than the second gap (G2).