IRS (AE og kafli 19) Flashcards
nefndu tvennt sem IRS hefur fram yfir INS og eitt sem er verra.
Betra: Shorter spin up time, more reliable
Verra: suffers laser lock.
An IRS consists of a ___, generating two _____.
Laser, light waves
IRS measures rotation motion about sensitive axis. Measures ____ and angular ____.
measures accelerations and angular rates.
Til að koma í vegn fyrir lock-in (sem getur gerst í low input rotation) í IRS kerfi þá er notuð aðferð sem kallast
Dithering
Í IRS, eru accelerometers og platform strapped down?
já
Alignment of an IRS consists of searching for the local ___, searching for true north, searching for the ___tude, comparison between the computed ___tude and the one entered by the pilot
vertical, latitude, latitude
Output data of an IRS is..
a) satellite number
b) Mach number
c) GS
d) true track
c) GS
d) true track
Hvaða mode selectors eru í boði í IRS frá vinstri til hægri?
OFF - ALIGN - NAV - ATT
Output úr Accelerometers í INS/IRS er integreitað einu sinni til að fá X og tvisvar til að fá Y.
X: Velocity (til að reikna velocity þarftu held ég initial speed)
Y: Distance (til að reikna distance þá þarftu held ég initial distance).
Strapdown IRS mælir hvað? (tveir hlutir)
Accelerations og Angular rate.
Hvað er strap down system?
Gyros og accelerometers are a part of the units fixture to the aircraft structure.
A ring laser gyro can measure rotation about it’s
sensitive axis
The alignment of a strapdown inertial system consists in measuring the _____ and local gravitation to position the reference ____.
earth rotation, trihedron.
In an IRS, accelerations are measured in relation to the ____.
aircraft axis.
Þegar þú ert í mid-latitudes, getur þú alignað INS/IRS í bæði ALIGN og NAV mode?
já
Eru accelerometers/gyroscopes/flow inductors að taka þátt í local vertical alignment of an inertial strap-down unit?
accelerometers
A laser gyro can measure
rotation motion.
Alignment time at mid latitudes for an inertial reference system using laser ring gyros is approx.
10 minutes. INS tekur 20 mín.
5 min at equator, 17 minutes 70°N - 78°N
A laser gyro can measure
a) rotation
b) acceleration
c) both
a) rotation
Hvað tekur alignment time í mid latitudes langan tíma fyrir IRS?
10 mínútur
Dither is used in a laser gyro in order to:
a. enhance the accuracy of the gyro at all rotational rates
b. increase the maximum rotational rate that can be sensed by the gyro
c. stabilize the laser frequencies at peak power output
d. break the frequency lock which would prevent small rotational rates from being sensed by the gyro
d. break the frequency lock which would prevent small rotational rates from being sensed by the gyro
The IRS can be a central source of information for which of an aircraft’s other systems?
- stability augmentation system
- weather radar
- air conditioning
- anti-skid auto brake system
- hydraulic accumulators
- vertical speed indication
- stability augmentation system
- weather radar
- anti-skid auto brake system
- vertical speed indication
Which facilities of an IRS were not normally available from the earlier INS?
a. pitch and roll
b. windspeed and drift
c. true heading and groundspeed
d. magnetic data base and a vertical channel
d. magnetic data base and a vertical channel
What of the following are the inputs required for an IRS?
- 3 ring laser gyros
- radio height
- 3 inertial accelerometers
- VHF communications
- initial present position
- barometric altitude
- TAS
- 3 ring laser gyros
- 3 inertial accelerometers
- initial present position
- barometric altitude
- TAS
