INS Flashcards
Hvað velur þú til að fá desired track and status?
DSR TK/STS
During initial alignment, an INS is north aligned by inputs from the..
a) Horizontal accelerometers and the east gyro
b) remote reading compass system
a) Horizontal accelerometers and the east gyro
Output data from the INS is..
acceleration north/south and east/west, attitude and true heading.
In a stabilized platform inertial system, the accelerations are measured in a trihedron which is
a) free from the aircraft trihedron
b) fixed in absolute space
a) free from the aircraft trihedron
Hver er aðalmunurinn á IRS og INS? (Tveir hlutir)
IRS notar Ring laser gyro.
IRS notar strap down í stað gyro stabilized platform.
Hvernig er GS fundinn út með INS? By integrating..
the measured acceleration.
Hvaða gyro er notað við alignment?
acceleration sensed by the east gyro horizontal accelerometer
The accuracy of the altitude computed by a stand alone inertial system decreases exponentially/proportionally with flight time.
exponentially.
Hvernig virkar þetta “integration fo find speed/distance” ?
Í hnotskurn þá er fyrst mælt speed (hversu hratt á 10 sek) og svo er mælt distance (hversu langt á þessum hraða í 10 sek).
Dæmi: Til að finna distance travelled þá myndir þú integrate once the speed in time. (Væntanlega þyrftir þú þá að integrate twice the acceleration).
Hvaða mode eru í boði í INS og hver er munurinn á þessum modes og IRS?
OFF - STBY - ALIGN - NAV - ATT
IRS er ekki með STBY mode.
The platform is levelled before azimuth alignment. True/false?
true
Where is the INS updated
only on the ground
What characteristics of earth are used when aligning an INS platform?
a) earth magnetic field
b) longitude
c) earth rotation
d) gravity
Earth rotation and gravity
Ef central air data computer bilar þá mun INS ekki gefa þér
a) wind direction and speed
b) GS
a) wind direction and speed
Hvaða græjur af neðangreindum nota rate integrating gyro?
a) inertial attitude system
b) autopilot system
c) Stabilizer servo mechanism system
d) inertial navigation unit
e) rate of turn indicator
a) inertial attitude system
d) inertial navigation unit
Hér er lykillinn held ég að sjá að þetta er INTEGRATING, þá er þetta væntanlega bara fyrir hluti sem eru notaðir í INS/IRS, held að engin önnur græja sé að integrate’a.
The position error of a standalone inertial system is approximately X - X NM per hour.
0.5 - 2 NM per hour.
Hvort kemur á undan “horizontal alignment” eða “unit orientation calculation”
Horizontal alignment er gert á undan unit orientation calculation. Meikar sens, værir nú varla að “calculate’a” neitt ef þú ert ekki rétt aligned.
Hvaða upplýsingum er INS computer að koma til platformsins sjálfs?
Upplýsingum um rate corrections to the gyros.
In a stabilised platform inertial system, the accelerations are measured in a trihedron which is ___ from the aircraft trihedron.
free.
Annað en í IRS en þar er þetta læst niður.
Horizontal alignment; hvort kemur á undan a) horizontal alignment eða b) unit orientation calculation
a) horizontal alignment
Fyrst alignar þetta sig og svo orientar.
í INS er talað um bounded og unbounded errors. Hvað er unbounded error?
An “unbounded error” is an error that increases with time, an example being the distance gone error due to a ground speed error
In an INS the E/W accelerations are converted into an E/W speed (kt) at the first stage of integration and into E/W distance gone (NM) at the second stage of integration. This gives ____.
departure.
Departure is multiplied by ____ of the present latitude to obtain d’long which is used to automatically update the present longitude.
secant
The amber ALERT light on an INS control and display unit:
a. illuminates steadily 2 minutes, in AUTO mode, before reaching the next waypoint
b. start flashing 2 minutes before reaching the next waypoint and goes out at 30 seconds to run
c. illuminates if power from the aircraft bus bar has been lost and the system is operating on standby battery
d. illuminates steadily after passing a waypoint in manual mode, until the next leg is programmed in
a. illuminates steadily 2 minutes, in AUTO mode, before reaching the next waypoint
With reference to Inertial Navigation Systems, the functions of the integrators are:
i) at the second stage of integration to suppress unbounded errors (when in the NAV mode)
ii) at the first stage of integration to convert acceleration, with respect to time, into speed, (when in NAV mode)
iii) at the second stage of integration to convert speed, with respect to time, into distance gone, (when in the NAV mode)
iv) to align the platform (when in the level and align modes)
Bara ii) og iii) eru rétt.
Integrators eru greinilega ekki að stilla INS kerfið af. Væntanlega eru integrators bara til að reikna.
The computer of a north referenced Inertial Navigation System (INS) in flight, provides compensation for:
a. aircraft manoeuvres, real wander, apparent wander, transport wander
b. coriolis, real wander, apparent wander, transport wander
c. earth rotation, transport wander, coriolis
d. transport wander, apparent wander, coriolis, magnetic variation
c. earth rotation, transport wander, coriolis
Compensatar greinilega EKKI fyrir apparent wander eða real wander…
INS er væntanlega ekki heldur að laga til “aircraft manoeuvres”..
Þegar þú ert að initializa INS, hvað þarftu að gera áður en þú hreyfir vélina?
Stilla á NAV.
