Systems, methods, and apparatuses for monitoring weld quality
An arc welder including an integrated monitor is disclosed. The monitor is capable of monitoring variables during a welding process and weighting the variables accordingly, quantifying overall quality of a weld, obtaining and using data indicative of a good weld, improving production and quality control for an automated welding process, teaching proper welding techniques, identifying cost savings for a welding process, and deriving optimal welding settings to be used as pre-sets for different welding processes or applications.
1. A method of quantifying a weld's quality by monitoring an electric arc welder as the electric arc welder performs a selected arc welding process by creating actual welding parameters between an advancing wire and a workpiece, said selected arc welding process controlled by command signals to a power supply of said electric arc welder, said method comprising:
(a) generating a series of rapidly repeating wave shapes, each wave shape constituting a weld cycle with a cycle time;
(b) dividing said wave shapes into states;
(c) measuring a plurality of selected weld parameters occurring in one or more of said states at an interrogation rate over a period of time repeatedly during said arc welding process;
(d) calculating a plurality of quality parameters for each of said states based on said measurements of said selected weld parameters during said welding process;
(e) comparing a value of each of said quality parameters calculated for each period of time to a corresponding expected quality parameter value to determine if a difference between said calculated quality parameter value and said expected quality parameter value exceeds a predetermined threshold; and
(f) when said difference exceeds said predetermined threshold, weighting said calculated quality parameter value with a magnitude weight based on said difference, and weighting said calculated quality parameter value with a time contribution weight based on a time contribution of its state to the wave shape including said state,
wherein said quality parameters represent an overall quality measurement of said weld.
2. The method of claim 1 , wherein said interrogation rate is 120 kHz.
3. The method of claim 1 , wherein said period of time is approximately 250 ms.
4. The method of claim 1 , wherein said selected weld parameters are measured for all of said states.
5. The method of claim 1 , further comprising:
(g) using said quality parameters in a metric to evaluate subsequent welds.
6. A method of quantifying a weld's quality by monitoring an electric arc welder as the electric arc welder performs a selected arc welding process by creating actual welding parameters between an advancing wire and a workpiece, said selected arc welding process controlled by command signals to a power supply of said electric arc welder, said method comprising:
(a) generating a series of rapidly repeating wave shapes, each wave shape constituting a weld cycle with a cycle time;
(b) dividing said wave shapes into states;
(c) measuring a plurality of selected weld parameters occurring in one or more of said states at an interrogation rate over a period of time repeatedly during said welding process; and
(d) calculating a plurality of quality parameters for each of said states based on said measurements of said selected weld parameters during said arc welding process,
wherein said selected weld parameters include, for each of said states, a count of said measurements taken for each of said selected weld parameters in said period of time, a mean voltage voltage in said period of time, a root mean square voltage RMSV in said period of time, a voltage variance V var in said period of time, a mean current current in said period of time, a root mean square current RMSI in said period of time, and a current variance I var in said period of time,
wherein voltage =a sum of voltages measured in said period of time/said count of voltage measurements,
wherein
R
M
S
V
=
∑
i
=
1
N
(
voltage
i
)
2
N
,
wherein V var =RMSV− voltage ,
wherein current =a sum of currents measured in said period of time/said count of current measurements,
wherein
R
M
S
I
=
∑
i
=
1
N
(
current
i
)
2
N
,
wherein I var =RMSI− current ,
wherein N is a total number of weld cycles in said period of time,
wherein voltage i refers to a voltage measurement for a specific one of the weld cycles in said period of time,
wherein current i refers to a current measurement for a specific one of the weld cycles in said period of time, and
wherein said quality parameters represent an overall quality measurement of said weld.
7. The method of claim 6 , wherein said quality parameters include a quality count average QCA for each state calculated as:
Q
C
A
=
∑
i
=
1
N
count
i
N
,
wherein count i refers to said count of said measurements for a specific cycle in said period of time.
8. The method of claim 7 , wherein said quality parameters include a quality count standard deviation QCSD for each state calculated as one of:
Q
C
S
D
=
∑
i
=
1
N
(
count
i
-
Q
C
A
)
2
N
-
1
,
and
Q
C
S
D
=
∑
i
=
1
N
(
count
i
-
Q
C
A
)
2
N
.
9. The method of claim 6 , wherein said quality parameters include a quality voltage average QVA for each state calculated as:
Q
V
A
=
∑
i
=
1
N
voltage
i
N
.
10. The method of claim 9 , wherein said quality parameters include a quality voltage standard deviation QV SD for each state calculated as one of:
Q
V
S
D
=
∑
i
=
1
N
(
voltage
i
-
Q
V
A
)
2
N
-
1
,
and
Q
V
S
D
=
∑
i
=
1
N
(
voltage
i
-
Q
V
A
)
2
N
.
11. The method of claim 6 , wherein said quality parameters include a quality current average QIA for each state calculated as:
Q
I
A
=
∑
i
=
1
N
current
i
N
.
12. The method of claim 11 , wherein said quality parameters include a quality current standard deviation QISD for each state calculated as one of:
Q
I
S
D
=
∑
i
=
1
N
(
current
i
-
Q
I
A
)
2
N
-
1
,
and
Q
I
S
D
=
∑
i
=
1
N
(
current
i
-
Q
I
A
)
2
N
.
13. The method of claim 6 , wherein said quality parameters include a quality voltage variance average QVVA for each state calculated as:
Q
V
V
A
=
∑
i
=
1
N
V
var
i
N
.
14. The method of claim 13 , wherein said quality parameters include a quality voltage variance standard deviation QVVSD for each state calculated as one of:
Q
V
V
S
D
=
∑
i
=
1
N
(
V
var
i
-
Q
V
V
A
)
2
N
-
1
,
and
Q
V
V
S
D
=
∑
i
=
1
N
(
V
var
i
-
Q
V
V
A
)
2
N
-
1
.
15. The method of claim 6 , wherein said quality parameters include a quality current variance average QIVA for each state calculated as:
Q
I
V
A
=
∑
i
=
1
N
V
var
i
N
.
16. The method of claim 15 , wherein said quality parameters include a quality current variance standard deviation QIVSD for each state calculated as one of:
Q
I
V
S
D
=
∑
i
=
1
N
(
I
var
i
-
Q
I
V
A
)
2
N
-
1
,
and
Q
I
V
S
D
=
∑
i
=
1
N
(
I
var
i
-
Q
I
V
A
)
2
N
.