Inertial Navigation | Stable Platorm Flashcards
The platform is a gyro-stablised cluster of ___ accelerometers, in __ circular gimbals.
linear 3
The 3 accelerometers consist of:
- Two ___ ones in the _ and _ axis, for ___ sensing.
- One in the _ axis
linear X Y LNAV
Z
E and I bars may be used as they have ___ friction, otherwise some systems use pendulums
minimal
The E and I bars may be used because they are highly ___, so a high flux density in proportion to the inducting field can be provided, with a rapid response to changes.
permeable
The central arm is fed with ___ Hz _C, so the outer leg will pick up a secondary induced _C voltage, which is affected by the gap between the bars.
400 AC
If there is no acceleration, the legs have the same ___, but with ___ polarity
voltage, opposite
As the I bar moves away from the vertical, in the ___ direction __ the acceleration, the secondary induced voltage is amplified, phase detected and rectified to __, so that the torque can try to restore the accelerometer to the null position.
opposite to DC
The amount of current involved is ___ proportional to the acceleration experienced
directly
Phase detection ensures that the __ is of the right polarity to the I bar can be moved the right way
DC
A stable platform keeps the ___ and ___ axes oriented N-S and E-W and the _ axis aligned with local gravity
X and Y, Z
The stable platform ensures that the accelerometers do not mistake gravity for ___
acceleration
There are _ rate integrating gyros that measure and use changes in aircraft vectors to orient the stable platform
3
The output of the rate integrating gyros __creases as a function of their rate of displacement
in
Rate integrating gyros provide a much ___er output response for a given input that displacement gyros do
high
Rate integrating gyros are surrounded by ___ to eliminate friction and reduce bearing torques, and stop them precessing or toppling, rather than using a spring.
warm oil
