Electric press, bend-point detection method, and program
A detection unit for detecting a data row of a press position and a load at the press position; an input/storage unit for inputting and storing a value serving as a reference for determining a bend point in a relation between the press position and the load at the press position; a data-row calculation unit for calculating a data row of a press position and a load at a constant distance interval based on the data row of the press position and the load detected; a slope calculation unit for calculating a slope of the load based on the press position and the load at the press position detected; and a bend-point determination unit for determining a point, at which the calculated slope of the load exceeds the value serving as the reference for determining the bend point, as the bend point are provided.
1. An electric press comprising:
a detection unit configured to detect a first data row of a press position at a constant time interval and a load at the press position at the constant time interval;
an input and storage unit configured to input and store a value serving as a reference for determining a bend point in a relation between the press position and the load at the press position;
a data-row calculation unit configured to calculate a second data row of a press position and a load at a constant distance interval based on the first data row of the press position and the load detected;
a slope calculation unit configured to calculate a slope of the load based on the second data row of the press position and the load at the press position at the constant distance interval, according to a regression line, wherein the slope of the load is calculated by the following formula (i),
the
slope
of
the
load
=
n
∑
i
=
1
n
x
i
y
i
-
∑
i
=
1
n
x
i
∑
i
=
1
n
y
i
n
∑
i
=
1
n
x
i
2
-
(
∑
i
=
1
n
x
i
)
2
,
[
Formula
(
i
)
]
and wherein, in the formula (i), n denotes a number of data, xi denotes data of a pressurization part, and yi denotes data of the load; and
a bend-point determination unit configured to determine a point, at which, the calculated slope of the load exceeds the value serving as the reference for determining the bend point, as the bend point.
2. An electric press comprising:
a detection unit configured to detect a first data row of a press position at a constant time interval and a load at the press position at the constant time interval;
an input and storage unit configured to input and store a value serving as a reference for determining a bend point in a relation between the press position and the load at the press position;
a data-row calculation unit configured to calculate a second data row of a press position and a load at a constant distance interval in space of the press position and the load based on the first data row of the press position and the load detected;
a slope calculation unit configured to calculate a slope of the load based on the second data row of the press position and the load at the press position at the constant distance interval in the space of the press position, according to a regression line, wherein the slope of the load is calculated by the following formula (i),
the
slope
of
the
load
=
n
∑
i
=
1
n
x
i
y
i
-
∑
i
=
1
n
x
i
∑
i
=
1
n
y
i
n
∑
i
=
1
n
x
i
2
-
(
∑
i
=
1
n
x
i
)
2
,
[
Formula
(
i
)
]
and wherein, in the formula (i), n denotes a number of data, xi denotes data of a pressurization part, and yi denotes data of the load; and
a bend-point determination unit configured to determine a point, at which the calculated slope of the load exceeds the value serving as the reference for determining the bend point, as the bend point.
3. The electric press according to claim 1 , wherein the slope calculation unit smoothes the calculated data row of the press position at the constant distance interval and the load at the press position at the constant distance interval, and calculates the slope of the load based on the smoothed data row of the press position and the load at the press position.
4. A bend-point detection method of an electric press comprising at least a detection unit, an input and storage unit, a data-row calculation unit, a slope calculation unit, and a bend-point determination unit, the bend-point detection method including:
a first step of detecting a press position at a constant time interval and a load at the press position at the constant time interval by the detection unit;
a second step of inputting and storing a value serving as a reference for determining a bend point in a relation between the press position and the load at the press position by tire input and storage unit;
a third step of calculating a data row of a press position and a load at a constant distance interval based on a data row of the press position and the load detected by the data-row calculation unit;
a fourth step of calculating a slope of the load based on the data row of the press position and the load at the press position at the constant distance interval by the slope calculation unit, according to a regression line, wherein the slope of the load is calculated by the following formula (i),
the
slope
of
the
load
=
n
∑
i
=
1
n
x
i
y
i
-
∑
i
=
1
n
x
i
∑
i
=
1
n
y
i
n
∑
i
=
1
n
x
i
2
-
(
∑
i
=
1
n
x
i
)
2
,
[
Formula
(
i
)
]
wherein, in the formula (i), n denotes a number of data, xi denotes data of a pressurization part, and yi denotes data of the load; and
a fifth step of determining a point, at which the obtained slope of the load exceeds the value serving as the reference for determining the bend point, as the bend point by the bend-point determination unit.
5. A bend-point detection method of an electric press comprising at least a detection unit, an input and storage unit, a data-row calculation unit, a slope calculation unit, and a bend-point determination unit, the bend-point detection method including:
a first step of detecting a press position at a constant time interval and a load at the press position at the constant time interval by the detection unit;
a second step of inputting and storing a value serving as a reference for determining a bend point in a relation between the press position and the load at the press position by the input and storage unit;
a third step of calculating a data row′ of a press position and a load at a constant distance interval in space of the press position and the load based on a data row of the press position and the load detected by the data-row calculation unit;
a fourth step of calculating a slope of the load based on the press position and the load at the press position at the constant distance interval in the space of the press position by the slope calculation unit, according to a regression line, wherein the slope of the load is calculated by the following formula (i),
the
slope
of
the
load
=
n
∑
i
=
1
n
x
i
y
i
-
∑
i
=
1
n
x
i
∑
i
=
1
n
y
i
n
∑
i
=
1
n
x
i
2
-
(
∑
i
=
1
n
x
i
)
2
,
[
Formula
(
i
)
]
wherein, in the formula (i), n denotes a number of data, xi denotes data of a pressurization part, and yi denotes data of the load; and
a fifth step of determining a point, at which the obtained slope of the load exceeds the value serving as the reference for determining the bend point, as the bend point by the bend-point determination unit.
6. The electric press according to claim 2 , wherein the slope calculation unit smoothes the calculated data row of the press position at the constant distance interval in the space of the press position and the load at the press position at the constant distance interval in the space of the press position, and calculates the slope of the load based on the smoothed data row of the press position and the load at the press position at the constant distance interval in the space of the press position.