| Taguchi
type experimental
designs distinguish between
'noise' factors and 'control' factors. Control
factors are put in the 'inner array' and
noise factors in the outer array. An example
is shown below. The experiment is to find
the best values for the three design features
in a relief valve: Hole Size, Spring Length
and Ball Size. The noise factors are the
Oil Temperature and Water Vapor Pressure.
| |
Outer
Array |
| D
Oil Temperature |
1 |
2 |
1 |
2 |
|
| E
Water Vapor Pressure |
1 |
1 |
2 |
2 |
|
| |
Inner
Array |
|
|
|
|
|
| |
A
(hole) |
B
(spring) |
AB |
C
(ball) |
AC |
BC |
- |
|
|
|
|
|
| Treatment |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
|
|
|
|
S/N
Min |
| 1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
44.9 |
51.9 |
52.6 |
59.9 |
-34.42 |
| 2 |
1 |
1 |
1 |
2 |
2 |
2 |
2 |
102.0 |
113.5 |
125.0 |
99.0 |
-40.86 |
| 3 |
1 |
2 |
2 |
1 |
1 |
2 |
2 |
47.3 |
51.3 |
54.1 |
61.1 |
-34.60 |
| 4 |
1 |
2 |
2 |
2 |
2 |
1 |
1 |
111.0 |
103.0 |
104.0 |
127.5 |
-40.97 |
| 5 |
2 |
1 |
2 |
1 |
2 |
1 |
2 |
157.8 |
157.2 |
154.3 |
165.2 |
-44.01 |
| 6 |
2 |
1 |
2 |
2 |
1 |
2 |
1 |
188.5 |
194.0 |
211.5 |
197.5 |
-45.94 |
| 7 |
2 |
2 |
1 |
1 |
2 |
2 |
1 |
148.6 |
159.5 |
198.0 |
176.7 |
-44.70 |
| 8 |
2 |
2 |
1 |
2 |
1 |
1 |
2 |
220.0 |
198.5 |
217.5 |
220.0 |
-46.62 |
| S/N
avg @ 2 |
-45.31 |
-41.72 |
-41.38 |
-43.59 |
-42.63 |
-41.52 |
-41.52 |
|
|
|
|
|
| S/N
avg @ 1 |
-37.71 |
-41.31 |
-41.65 |
-39.43 |
-40.39 |
-41.50 |
-41.51 |
|
|
|
|
|
| Δ
S/N |
-7.60 |
-0.41 |
0.27 |
-4.16 |
-2.24 |
-0.02 |
-0.01 |
|
|
|
|
|
The analysis gives the control factor settings
that maximize the Signal
to Noise Ratio and hence minimize
the loss.
|
