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Pedestrian
Dead
Reckoning
with Inertial Motion Units
The LOPSI group employs Inertial
Navigation methods to estimate
the current position of a person
from the measurements obtained from Inertial Measurement Units (IMU)
carried
by him (usually foot-mounted).
A
foot-mounted Inertial Measurement
Unit (IMU), manufactured by Xsens,
is used to estimate the displacement and current position of a
person.
Inertial Navigation is subject
to drift: the accumulation of
measurement errors which increases the positioning error with time.
Combining the precise but relative position estimates produced by INS
with the inaccurate but absolute estimates of RFID tags, we obtain
high precision positioning of a person in our building, as shown below:
 
Position estimates with INS
methods accumulate errors as the length of the trajectory increases
(left), but they can be compensated with the use of an absolute
positioning system like an RFID-LPS (right). |
