Trajectory Profile & SIMU Sensor Simulation
The SIMU sensor simulation can be seen as an inverse data processing problem of
traditional SINS updating algorithm. The first step is to obtain an appropriate trajectory profile,
including the vehicle’s angular/linear displacement information, i.e. attitude function
� �
T
)()()( ttt
���
�A
and position function
� �
T
)()()( thttL
�
�p
with respect to
time.
A) Trajectory Profile Simulation
For description convenience, a new frame (t-frame) is defined, whose y-axis is along the
trajectory forward direction, while x-axis is in the local level plane and points to the trajectory
right direction, together with z-axis being a right-hand coordinate system. By contrast with
n
b
C
,
it easy to obtain the transformation matrix from t-frame to n-frame, as
�
�
�
�
�
�
�
�
�
�
�
�
�
��
�����
�����
cossin0
cossincoscossin
sinsinsincoscos
n
t
C
In our trajectory simulation scenario, the Euler angular rate
� �
T
���
��
�
�w
=
� �
T
���
���
and trajectory acceleration
� �
T
t
x
t
x
t
x
t
aaa�a
are taken as original inputs
to generate the profile [
A
,
p
], with the whole set of differential equations listed as follows
�
�
�
�
�
�
�
�
n
pv
tn
t
n
vMp
aCv
wA
�
�
�
(10.8-1)
Note that sideslip angle and attack angle are both not considered, or always equal 0, in the
above trajectory integral models.
A trajectory profile is typically consists of several segments, such as uniform velocity,
uniform acceleration, pitching, rolling and turning. The input parameters for each segment are
described in brief as follows.
(1) Uniform velocity (including static):
� �
T
000�w
,
� �
T
000�
t
a
.
(2) Uniform acceleration:
� �
T
000�w
,
� �
T
00
t
y
t
a�a
, where
t
y
a
is the
acceleration along forward direction.
(3) Pitching:
� �
T
00
�
�
�w
,
� �
T
000�
t
a
, where
�
�
is the pitching angular
rate.
(4) Rolling:
� �
T
00
�
�
�w
,
� �
T
000�
t
a
, where
�
�
is the rolling angular rate.
