7/24/2019 Particulars About INS and IRS
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Particulars about INS and IRS
INS:- During initial alignment an INS is north aligned by inputs
from
horizontal accelerometers and the east gyro i.e.
acceleration
sensed by the east gyro horizontal accelerometer- During initial
alignment, the euipment !ill not accept a "#o
error in initial latitude but !ill accept a "#o error in
initiallongitude
- $hen initial position is input to the %&S, the system
re'ects initiallatitude or longitude error
- (fter alignment of the stable platform of INS, the output
datafrom the INS computer to the platform is the rate corrections
tothe gyro, the output data from the platform is acceleration north
)south and east)!est, attitude and true heading
- *he platform of an inertial na+igation system is maintained
atright angles to the local +ertical by applying corrections for
theeects of aircraft manoeu+res, earth rotation, transport
!anderand oriolis.
- Drift refers to the !ander of the ais of a gyto in the
horizontalplane.
- *(S is reuired to be input to the INS to obtain $) readout,
thepurpose of this is for calculation of !ind +elocity.
-
IRS- IRS sensors includes accelerometers, laser gyros, mounted
in the
direction of the aircraft ais- In an IRS, accelerometers and
platform are both strapdo!n- Some inertial reference systems are
/no!n as strapdo!n- Strap do!n means the gyroscopes and
accelerometers become
part of the unit 0ed to the aircraft structure- In a ring laser
gyro, the purpose of the dither motor is to
o+ercome laser loc/
Problems associated !ith stabilized platforms:". *he accuracy of
a platform type INS is strongly dependent on the
accuracy of maintaining orientation of the locally le+el
platform.Since gyros are the sensors used to achie+e platform
stability,gyro errors aect the accuracy of the platform. *hree
accelerometers are in+ol+ed and since the acceleration
isintegrated t!ice, acceleration errors are important
