Biomedical Engineering Reference
In-Depth Information
X
k
2
err
¼
ð
r
i
r
m
Þ
:
(8.113)
i¼
1
On the basis of these calculations, the algorithm of the optimum search can be
created. The algorithm finds values
X
0
,
Y
0
, which minimize the error
err
. Let, in
this point, the medium distance
r
m
be
r
m
. Then the diameter
d
s
of the pin can be
calculated:
r
m
d
s
¼
d
d
;
2
(8.114)
where
d
d
is the diameter of the metallic disc.
In order to define the cutter position relative to the pin, a similar procedure is
performed. The only difference is that the experimental points are defined with the
contact of the cutter end point with the pin. For this measurement, we use only a
quarter of the circle, beginning at the lower pin part and ending at the pin axis level.
The experiments with the micromachine tool prototype are demonstrated in
Figs.
8.37
and
8.38
. The cutter, the pin, and the metallic measurement disc are
demonstrated in large scale in Fig.
8.39
.
Pins of different diameters (from 3 millimeters to 0.4 millimeters) were pro-
duced and measured by the described process. Thereafter, they were measured with
a micrometer that had a resolution of 1
m
m. The medium error of the diameter's
value was 8
m
m, and the maximum error was 22
m
m. Without using the adaptive
algorithm, the manufacturing errors reach 60
m
m.
Fig. 8.39 Pin, cutter, and metallic measurement disc
