International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B5. Istanbul 2004
2 EQUIPMENT USED IN THE PRESENT STUDY
As mentioned in the previous section, servo-type
accelerometers and two types of gyros were used in the
present study. Their specifications are listed in table 1
through table 3. As shown in figure 1, a strap-down
inertial navigation system was constructed by attaching
an accelerometer and a gyro to each of three mutually
orthogonal axes. Figure 2 shows the equipment made on
an experimental basis, which was used in the present
study.
Axis-Z
Accelerometer
Figure 2. Experimental equipment
3 MEASURMENT STRATEGY SUITABLE FOR
INERTIAL SURVEY
3.1 Route alignment
Experiments were performed on the asphalt-paved road
- with about 5.5 m elevation difference and 164 m inclined
length. Alignment of the road was measured in detail
using a total station and a digital level, and the result was
considered as the true alignment in the following
experiments concerned with our inertial survey system.
Figure 3 and 4 show the plane and the vertical alignment,
respectively, used in the experiments.
B Lii. bom ibi
Table 1. Specification of accelerometer JA-5V
Item
Specification
Resolution
«1x10 (with LP filter)
Sensitivity
5V/G +3%
Zero point unbalance < 40.01%
Largest measuring range +20
Lateral sensitivity <0.01%
POWER SUR Voltage +12 — =18V DC
Current « 20mA
Weight « 80gf
Table 2. Specification.of Vibration gyro ENV-05A
Item Specification
Resolution 0.1°/s
Detection range +90°/s
Responsibility DC — 7Hz
Power sup. Voltage +8 ~ 413.5V DC
Current <15mA
Weight <45gf
Table 3. Specification of fiber optical gyro JG-35FD
Item Specification
Resolution 0.06°/s
Detection range +90°/s
Responsibility DC — 20Hz
PWer sp: Voltage 12V DC
Current < | A
Figure 4. Running through chart
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