Inertial Navigation | AHRS

Question 1

AHRS stands for ____

Answer 1

Altitude and Heading Reference System

Question 2

AHRS replaces ____ ___ and their problems

Answer 2

traditional gyros

Question 3

The problems which AHRS aims to eliminate include:

Answer 3

• Drift
• Topple
• Gimbal lock

Question 4

AHRS is generally installed in aircraft which do not had a ___

Answer 4

IRS

Question 5

AHRS consists of a group of inertial sensors in one package that can output ___, ___, and ___ information to flight deck displays.

Answer 5

attitude, heading, and glitch dynamics

Question 6

A ___ valve and ADC are involved.

Answer 6

flux

Question 7

3D orientation is obtained by integrating the gyroscopes with ___ and ___

Answer 7

accelerometers, megneotmeters

Question 8

AHRS requires ___ power, ___ wiring, weighs ___, and has a ___ footprint.

Answer 8

less less less smaller

Question 9

Micro Electro Mechanical System gyroscopes have __ power requirements and costs by using ___ ___ to measure the angular rate

Answer 9

low Coriolis Effect

Question 10

Most use a ___ fork assembly

Answer 10

tuning

Question 11

With the tuning fork configuration, two masses oscillate and move constantly in ___ directions

Answer 11

opposite

Question 12

During linear acceleration, two masses move in the ___ direction, meaning no change in capacitance will be detected

Answer 12

same

Question 13

When angular velocity is applied, the coriolis force on each mass produces a change in ___ that is proportional to the angular velocity, which is then converted into output voltage.

Answer 13

capacitance

Question 14

The magnetometer will usually be mounted remotely from the AHRS, where magentic disturbances are ___

Answer 14

minimal

Question 15

Three different types of MEMS exist:

Answer 15

• Accelerometers
• Rate Gyros
• Magnetometers

Question 16

MEMS gyros are called ___ gyros, becuse they measure __ ___ ___ ___ around the measuring axis.

Answer 16

rate gyro absolute rates of turn

Question 17

MEMS have no moving parts, so are ___ accurate as well as ___ wear-free

Answer 17

highly, almost

Question 18

A MEMS gyro is a mass suspended by ___ springs, which can move in one plane

Answer 18

four

Question 19

The device is sensitive to rotations around the axis which is ___ to the plane

Answer 19

vertical

Question 20

When the MEMS gyro is rotated around its sensitive axis, the ___ ___ causes another vibration within the plane ___ to the vibration induced by the motor

Answer 20

Coriolis force, perpendicular

Question 21

The magnitude of the second vibration is a measure for the ___ ___ ___, and is picked up as the electrical current induced in a ___ ___ ___ sensor

Answer 21

rate of rotation, piezo-electric crystal