Apparatus for reducing noise of gear pump through uneven pitch-simulated control and method thereof
An apparatus for reducing noise of a gear pump through uneven pitch-simulated control includes a calculation unit to calculate different control current values for each tooth of a teeth order by applying a teeth number, the teeth order, and a teeth angle of the gear pump in which a plurality of teeth are evenly formed, a storage unit to map and store the teeth order and the different control current values corresponding to the teeth order for each tooth, and a current controller to variably generate the control current value mapped corresponding to the teeth order when each tooth reaches a reference position when the gear pump rotates by a motor, wherein the control current value is added to a reference current value of a motor control signal and applied to the motor.
1. An apparatus for reducing noise of a gear pump through uneven pitch-simulated control, the apparatus comprising:
a calculation unit configured to calculate different control current values for each tooth of a teeth order by applying a teeth number, the teeth order, and a teeth angle of the gear pump in which a plurality of teeth are evenly formed to a predetermined function corresponding to a variable value between 10 and 90 applied differently based on a type of the gear pump;
a storage unit configured to map and store a control current value of the teeth order and the different control current values corresponding to the teeth order for each tooth; and
a current controller configured to variably generate the control current value mapped by the different control current values corresponding to the teeth order when each tooth reaches a reference position when the gear pump rotates by a motor, wherein the control current value is added to a reference current value of a motor control signal and applied to the motor.
2. The apparatus of claim 1 , wherein the current controller is configured to:
instantaneously generate the control current value mapped with the tooth corresponding to the teeth order at a time when the tooth corresponding to the teeth order reaches the reference position; and
apply only the reference current value to the motor during a remaining time when the control current value is not generated.
3. The apparatus of claim 1 , wherein the current controller is configured to variably generate the control current value corresponding to all teeth sequentially reaching the reference position according to time.
4. The apparatus of claim 3 , wherein a pattern of the control current, value according to time has a sine function form.
5. The apparatus of claim 1 , wherein an n-th control current value corresponding to an n-th teeth order is calculated from an equation
i
uneven
ref
=
I
Δθ
n
×
e
-
B
m
{
mod
(
θ
,
2
π
N
)
-
1
}
2
,
in which N denotes the tooth number, n denotes the teeth order (n=1, 2, . . . , N), 2π/N denotes the tooth angle, I Δθn denotes a basic current value applied to the n-th tooth, e(⋅) denotes an exponential function for adjustingI Δθn , and B m is the variable value.
6. The apparatus of claim 5 , wherein the I Δθn is calculated from an uneven pitch generating function
I
Δθ
n
=
(
-
1
)
n
·
A
m
{
sin
(
P
1
3
6
0
N
n
)
×
cos
(
P
2
360
N
n
)
}
,
in which Am denotes a current reference value and has a range of 5A±20%, P 1 and P 2 are factors that affect a period of the basic current value, o<P 1 <N, and o<P 2 <N.
7. A method for reducing noise of a gear pump through an uneven pitch-simulated control, the method comprising:
calculating different control current values for each tooth of a teeth order by applying a teeth number, the teeth order, and a teeth angle of the gear pump in which a plurality of teeth are evenly formed to a function corresponding to a variable value between 10 and 90 applied differently based on a type of the gear pump;
mapping and storing a control current value of the teeth order and the different control current values corresponding to the teeth order for each tooth; and
variably generating the control current value mapped with the teeth order when the tooth sequentially reaches a reference position, wherein the control current value is added to a reference current value of a motor control signal and applied to a motor.
8. The method of claim 7 , wherein:
the control current value mapped with the tooth corresponding to the teeth order is instantaneously generated at a time when the tooth corresponding to the teeth order reaches the reference position; and
only the reference current value is applied to the motor during a remaining time when the control current value is not generated.
9. The method of claim 7 , wherein the control current value is variably generated corresponding to all teeth sequentially reaching the reference position according to time.
10. The method of claim 9 , wherein a pattern of the control current value according to time has a sine function form.
11. The method of claim 7 , wherein an n-th control current value corresponding to an n-th teeth order is calculated from an equation
i
uneven
ref
=
I
Δθ
n
×
e
-
B
m
{
mod
(
θ
,
2
π
N
)
-
1
}
2
,
in which N denotes the tooth number, n denotes the teeth order (n=1, 2, N), 2π/N denotes the tooth angle, I Δθn denotes a basic current value applied to the n-th tooth, e(⋅) denotes an exponential function for adjusting I Δθn , and Bm is the variable value.
12. The method of claim 11 , wherein the I Δθn is calculated from an uneven pitch generating function
I
Δθ
n
=
(
-
1
)
n
·
A
m
{
sin
(
P
1
3
6
0
N
n
)
×
cos
(
P
2
360
N
n
)
}
,
in which Am denotes a current reference value and has a range of 5A±20%, P 1 and P 2 are factors that affect a period of the basic current value, o<P 1 <N, and o<P 2 <N.
13. An apparatus comprising:
a gear pump that includes a gear with a plurality of teeth that are evenly formed;
a motor coupled to drive the gear pump;
a processor configured to calculate different control current values for a function corresponding to a variable value between 10 and 90 applied differently based on a type of the gear pump, the different control current values being calculated for each tooth by applying a teeth number, a teeth order, and a teeth angle;
a memory configured to map and store a control current value of the teeth order and the different control current values corresponding to the teeth order for each tooth;
a current generator configured to variably generate the control current value mapped by the different control current values corresponding to the teeth order when each tooth reaches a reference position when the gear pump rotates by the motor; and
a current adder having inputs coupled to receive the generated control current value and a reference current value and an output coupled to the motor.
14. The apparatus of claim 13 , wherein the current generator is configured to:
instantaneously generate the control current value mapped with the tooth corresponding to the teeth order at a time when the tooth corresponding to the teeth order reaches the reference position; and
apply only the reference current value to the motor during a remaining time when the control current value is not generated.
15. The apparatus of claim 13 , wherein the current generator is configured to variably generate the control current value corresponding to all teeth sequentially reaching the reference position according to time.
16. The apparatus of claim 15 , wherein a pattern of the control current value according to time has a sine function form.
17. The apparatus of claim 13 , wherein an n-th control current value corresponding to an n-th teeth order is calculated from an equation
i
uneven
ref
=
I
Δθ
n
×
e
-
B
m
{
mod
(
θ
,
2
π
N
)
-
1
}
2
,
in which N denotes the tooth number, n denotes the teeth order (n=1, 2, N), 2π/N denotes the tooth angle, I Δθn denotes a basic current value applied to the n-th tooth, e(⋅) denotes an exponential function for adjusting I Δθn , and Bm is the variable value.
18. The apparatus of claim 17 , wherein the I Δθn is calculated from an uneven pitch generating function
I
Δθ
n
=
(
-
1
)
n
·
A
m
{
sin
(
P
1
3
6
0
N
n
)
×
cos
(
P
2
360
N
n
)
}
,
in which Am denotes a current reference value and has a range of 5A±20%, P 1 and P 2 are factors that affect a period of the basic current value, o<P 1 <N, and o<P 2 <N.