3.Accelerometer 
3.1Experiment for characteristics of accelerometer 
For the accelerometer,a servo-type accelerometer JA- 
VC1 manufactured by Japan Aviation Electronics 
Industry., LTD was used. 
The features of the accelerometer are to be capable of 
measuring microacceleroration with good 
precision, free from friction, wear 
looseness,and stable,small-size and light-weight. 
In order to grasp the characteristics of an 
accelerometer,an accelerometer was plased on a 
horizontal pedestal,and it was manually moved 50cm 
in the detection shaft direction of the 
accelerometer.The graph in Fig5 shows the 
acceleration,speed and change in distance from the 
beginning of the movement till the stop of the 
accelerometer. 
The graph for acceleration in Fig.5(A) shows the 
change in acceleration from the beginnig of the 
movement till the stop of the accelerometer.The 
voltage becomes(+) during acceleration while it 
becomes(-) during deceleration.It is because the 
accelerometer has been manually moved that the 
shape of the graph changes irregularly. 
The graph for speed in Fig.5(B) represents change in 
speed from the beginning of the movement till the stop 
of the accelerometer by a value obtained by integrating 
the voltage of the acceleration.It can be seen that the 
speed gradually increases on the contrary in the 
second half. This corresponds to a state when the 
accelerometer was moved. 
mechanical 
Fig.5(C) represents a distance obtained by integrating 
a speed.This graph shows a distance along which it has 
moved from the beginning of the movement,and the 
portion having a constant voltage value in the second 
half of the graph has a voltage(195.2V) corresponding 
to the moving distance of 50 cm. 
This characteristic experiment was performed in order 
to make sure that a voltage corresponding to the 
distance when it was stopped by changing the 
acceleration on the way after an accelerometer was 
moved becomes constant. The graph shows that the 
value obtained by double-integrating the acceleration 
data into a distance is constant where the movement 
was stopped. 
8 
(A) ACCELERATION 
  
OUTPUT VOLTAGE 
Ss 
  
  
  
AA 
TIME(1/20S) 
(B)VELOCITY 
  
OUTPUT VOLTAGE 
g le^. 
  
  
  
FATE TY EEE 
TIMBE(1/2085) 
(C)DISTANCE 
  
  
OUTPUT VOLTAGE 
  
  
TIME(1/208S) 
Fig .5 Acceleration,Velocity,Distance 
3.2Distance measuring experiment in the plane 
direction 
In order to practically calculate the moving distance in 
the plane direction,survey points were provided at 
intervals of about 10m,20mand 30m with ethron tape 
on a horizontal corridor on the 7th floor of large 
building No.4 of Chiba Institute of Technology,and the 
carriage was moved in the direction of detection 
shaft(X-axis direction in this experiment) of the 
accelerometer to allow only the accelerometer in the 
X-axis direction to output. 
In the experiment,the carriage was assumed to be 
horizontal all the time,an angle of rotation (x ) in the 
horizontal direction was calculated by using a 
vibration gyro installed to the Z-axis,and coordinate 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B1. Vienna 1996 
transf 
of X=( 
the pl 
gyro v 
attach 
The 
10m, a 
30m. ' 
1.3296 
of 20i 
movin 
3.3Dis 
direct 
Next, i 
verticé 
along 
accele 
pedest 
the le 
up to : 
the le 
seconc 
about 
0.60% 
for 15( 
The a: 
output 
detect 
vertic: 
Accorc 
when 
gravit; 
in the 
been 1 
above- 
horizo 
follow; 
owing 
accum 
© the 
directi 
transf 
that it 
4.1Le 
In ord 
height 
device 
with a 
For tk 
0.469n