Week 4: Gyroscopic Basics

Question 1

Why do we use gyros?

Answer 1

For stability

Question 2

When do we use gyro instruments?

Answer 2

When visibility was poor

Question 3

Which instruments rely on a gyro?

Answer 3

Turn Coord
Directional Gyro
ADI
Gyro stabilized compass

Question 4

When will a spinning object exhibit gyroscopic properties?

Answer 4

When it reaches the correct speed

Question 5

What are the 2 important design considerations for a gyro?

Answer 5

Great weight, small size (high density)

high speed rotation with low friction

Question 6

What makes the gyro have less friction?

Answer 6

Bearings

Question 7

The heavier the gyro means what for the speed?

Answer 7

Slower speed needed

Question 8

What are the 2 properties of a gyro?

Answer 8

Precession and Rigidity

Question 9

What is Rigidity?

Answer 9

When a gyro rotates at high speed, it will remain rigid in the plane it is spinning

Question 10

What is Precession?

Answer 10

A force acted upon a gyro will be felt 90degrees after the point of application

Question 11

When do you cage the gyro?

Answer 11

Before spinning up

Question 12

What are the 2 things that create rigidity?

Answer 12

Mass and speed (increase=increase rigidity)

Question 13

A gyro has what kind of momentum?

Answer 13

Angular momentum

Question 14

What are the pivot points that allow the gyro to rotate about its axes?

Answer 14

Gimbals

Question 15

Does the gyro or the case around it move?

Answer 15

Case around it

Question 16

The Degrees of Freedom classification disregards what?

Answer 16

The rotors spin axis/plane

Question 17

What is the term used to indicate the number of directions in which the rotor is free to move?

Answer 17

Degrees of Freedom

Question 18

1 gimbal is equal to how many degrees of freedom?

Answer 18

1 degree of freedom

Question 19

What type of gyro uses 1DOF and 1 GImbal

Answer 19

Rate gyros

Question 20

If spin axis of gyro is parallel to direction of travel what can we measure?

Answer 20

Pitch

Question 21

What are the 2 types of mountings for a gyro?

Answer 21

Free (Universal)

Restricted (Semi-rigid)

Question 22

Free mounted are used on which gyros?

Answer 22

Direction and Attitude/vertical gyro

Question 23

When do we use restricted mounting?

Answer 23

where one of the planes of freedom are held in a fixed relation to base

Question 24

What do restricted mounting gyros have for temporary displacement?

Answer 24

Spring type mechanism

Question 25

Where do we use restricted mounting?

Answer 25

For applications where movement is compared to time

Question 26

Restricted mounting is also know as?

Answer 26

Rate gyro

Question 27

Which gyro has a spin axis PERPENDICULAR to the earths surface and what instrument does it use?

Answer 27

Vertical Gyro | ADI

Question 28

Which gyro has a spin axis PARALLEL to the earths surface and what instrument does it use?

Answer 28

Horizontal Gyro | Directional

Question 29

What is the tilting force that causes a gyro to precess?

Answer 29

Torque

Question 30

The farther away from the CofG the _______ torque you have to apply

Answer 30

Less

Question 31

If you want to turn, a turn rate gyro back to level what do you do?

Answer 31

Apply force on Tilt axis which will cause a turn

Question 32

What is wander?

Answer 32

Any movement of the spin axis away from the fixed direction

Question 33

gyro wander in the earths horizontal plane is called?

Answer 33

Drift (want N point E)

Question 34

What is topple?

Answer 34

gyro wander in Vertical plane (want E points S)

Question 35

What is real wander caused by?

Answer 35

Bearing friction Imbalance Inertia of gimbals

Question 36

What is apparent wander and what is it caused by?

Answer 36

Appears to wander, caused by obverses orientation

Question 37

What do we use torqueing motors for?

Answer 37

Slowing down gimbal inertia