Inertial Sensors

Question 1

What is Sperry’s rule?

Answer 1

Apparent point of application of a force to a gyroscope is 90deg from actual point of application in the direction of the spin.

Question 2

What is the rigidity of a gyroscope?

What is the precession of a gyroscope?

Answer 2

The tendency for a body to maintain uniform motion unless subjected to an external force - basis of attitude measurement
The change in rotational axis of a body in response to an external force - basis of rate measurement

Question 3

Name and describe the types of gyroscope wander.

Answer 3

True: Due to friction in bearings, mass in-balances etc.
Apparent
-Earth rate: Arising from the earths rotation rate (15deg/hour)
-Transport: arising from movement of the gyro across the curved surface of the earth (velocity/radius of earth)

Question 4

What do attitude gyroscopes tell us?
What to rate gyroscopes tell us?
What do accelerometers tell us?

Answer 4

Air craft orientation relative to local earth
Angular velocity relative to body axes
Components of airframe acceleration

Question 5

What does normal acceleration tell us?

What does lateral acceleration tell us?

Answer 5

Used in pitch-axis stabilisation

Relates to side slip and helps in performing balanced turns

Question 6

On an attitude gyroscope;
Horizontal spin axis tells us?
Vertical spin axis tells us?

Answer 6

Heading

Pitch/Roll