358
Camera moving Direction
Line camera
Scanning line
Distance of movement (D)
\
| Camera set angle(A)
Line camera
Scanning line
EI
_tan(A)= H/D_ |
Figure 8. How to measure the height
If set the camera incline angle at 30 degrees ,one
data line means about 0.5 millimeters height at speed
of 30 kilometers per hour.
The image processing involved following three steps:
(1) Preparation such as regulation of lightness of the image data
(2) Detection of the spring from the binarized image at the threshold value of shadow
(3) Calculation of the value of slit (Photo 4)
Basically ,0n the Sinkansen slab tracks , there no materials except for the tying spring will makes
a circular shadow . So, it is possible to detect the spring by the software , if the image data will
be binarized at level of shadow. According to the result of this processing , the part of spring
plate images are cut out by the software . ( Photo 4 ) On photo 4 , it is possible to recognize the
third spring plate had loosen by human eyes.
4. RESULT OF FIELD TEST
The following is the result of verification of this system on the field tests.
The image data of fasteners which exists on Shinkansen tracks under the actual condition had been
record. And those data are calculated by engineering work station.
Table 2. Compare between the Calculation result with real value of spring width
Difference fram Real Value (mm) Total
Real Value 00,05/|10/|15/20/|25|30|35|40/|45| 50]| 60| Cant
-]. 5mm 010101/01/0101/01.0/0|/01101|0 0
-]. Qm 0} 0 | O0 | 1 0: 0} 1 0 | 0} 1 1 0 4
-0. 5m 0! 14 | 7}? 6:6: 71101 1 5 [| 6] 4 | 0 66
0. Om 4 | 2} 75 | }? | B | 5} 1 3] 1 9 | 1 4]
+). 5mm 0 00 2 3 | 1 0 | 6} 0, 0) 0j 5 18
+. Om 0101 0| 1 2} 01 0/0) 0| 0] 0 | 2 5
+1. 5m 0 1 0; 010! O70 C0 07010100 0
IAPRS, Vol. 30, Part 5W1, ISPRS Intercommission Workshop “From Pixels to Sequences”, Zurich, March 22-24 1995
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