<s>
In	O
rotordynamics	O
,	O
order	B-Algorithm
tracking	I-Algorithm
is	O
a	O
family	O
of	O
signal	O
processing	O
tools	O
aimed	O
at	O
transforming	O
a	O
measured	O
signal	O
from	O
time	O
domain	O
to	O
angular	O
(	O
or	O
order	O
)	O
domain	O
.	O
</s>
<s>
In	O
some	O
cases	O
the	O
outcome	O
of	O
the	O
Order	B-Algorithm
Tracking	I-Algorithm
is	O
directly	O
the	O
Fourier	B-Algorithm
transform	I-Algorithm
of	O
such	O
angular	O
domain	O
signal	O
,	O
whose	O
frequency	O
counterpart	O
is	O
defined	O
as	O
"	O
order	O
"	O
.	O
</s>
<s>
Order	B-Algorithm
tracking	I-Algorithm
is	O
based	O
on	O
a	O
velocity	O
measurement	O
,	O
generally	O
obtained	O
by	O
means	O
of	O
a	O
tachometer	B-Device
or	O
encoder	O
,	O
needed	O
to	O
estimate	O
the	O
instantaneous	O
velocity	O
and/or	O
the	O
angular	O
position	O
of	O
the	O
shaft	O
.	O
</s>
<s>
Three	O
main	O
families	O
of	O
computed	O
order	B-Algorithm
tracking	I-Algorithm
techniques	O
have	O
been	O
developed	O
in	O
the	O
past	O
:	O
Computed	O
Order	B-Algorithm
Tracking	I-Algorithm
(	O
COT	O
)	O
,	O
Vold-Kalman	O
Filter	O
(	O
VKF	O
)	O
and	O
Order	B-Algorithm
Tracking	I-Algorithm
Transforms	O
.	O
</s>
<s>
Order	B-Algorithm
tracking	I-Algorithm
refers	O
to	O
a	O
signal	O
processing	O
technique	O
used	O
to	O
extract	O
the	O
periodic	O
content	O
of	O
a	O
signal	O
and	O
track	O
its	O
frequency	O
variations	O
over	O
time	O
.	O
</s>
<s>
In	O
order	O
to	O
track	O
the	O
order	O
of	O
a	O
signal	O
,	O
the	O
signal	O
is	O
first	O
transformed	O
into	O
the	O
frequency	O
domain	O
using	O
techniques	O
such	O
as	O
the	O
Fourier	B-Algorithm
transform	I-Algorithm
.	O
</s>
<s>
Computed	O
order	B-Algorithm
tracking	I-Algorithm
is	O
a	O
resampling	O
technique	O
based	O
on	O
interpolation	O
.	O
</s>
<s>
Order	B-Algorithm
tracking	I-Algorithm
transforms	O
are	O
mathematical	O
transforms	O
which	O
perform	O
in	O
a	O
single	O
step	O
both	O
the	O
order	B-Algorithm
tracking	I-Algorithm
(	O
synchronization	O
of	O
the	O
signal	O
domain	O
with	O
the	O
reference	O
shaft	O
)	O
and	O
the	O
Fourier	B-Algorithm
transform	I-Algorithm
to	O
assess	O
amplitude	O
and	O
phase	O
of	O
each	O
order	O
of	O
the	O
so	O
obtained	O
spectrum	O
.	O
</s>
<s>
The	O
most	O
recent	O
formulation	O
of	O
such	O
transforms	O
is	O
the	O
Velocity	O
Synchronous	O
Discrete	O
Fourier	B-Algorithm
Transform	I-Algorithm
,	O
defined	O
as	O
follows	O
:	O
</s>
