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Aircraft Position, Velocity and Attitude

Details

The Honeywell Laserref Innertial Reference System (IRS) uses ring laser gyros and servo accelerometers to measure horizontal, vertical and angular acceleration in the Cartesian aircraft reference system. The IRS internal computer determines aircraft position, attitude and velocity from the measured accelerations using advanced Kalmann filtering techniques to reduce drift errors from signal integration.

The Flight Management Computer (FMC) uses IRS, GPS and other navigation system to calculate a high precission blended position. Output from the IRS and FMC is used in calculations of aircraft motion and wind velocities.

Error Analysis

Instrument	Output	Unit	Accuracy	Resolution	Comment
Honeywell Laserref	IRS Actual Track Angle	[degree (0-360)]	5	0.1	Track angle of aircraft from inertial reference system
Honeywell Laserref	IRS Groundspeed	[m/s]	6	0.06	Groundspeed of aircraft from inertial reference system
Honeywell Laserref	IRS Acceleration (z-Direction)	[m/s^2]	0.01	0.001	Acceleration in downward direction of aircraft reference system
Honeywell Laserref	IRS Acceleration (x-Direction)	[m/s^2]	0.01	0.001	Acceleration in forward direction of aircraft reference system
Honeywell Laserref	IRS Acceleration (y-Direction)	[m/s^2]	0.01	0.001	Acceleration in sideward direction of aircraft reference system
Honeywell Laserref	IRS Vertical Acceleration	[m/s^2]	0.01	0.001	Vertical acceleration in earth reference system
Honeywell Laserref	IRS True Heading	[degree (0-360)]	0.4	0.1	Heading of aircraft (direction)
Honeywell Laserref	IRS Roll Angle	[degree (+-180)]	0.1	0.01	Roll angle of aircraft (wing up/down)
Honeywell Laserref	IRS Pitch Angle	[degree (+-180)]	0.1	0.01	Pitch angle of aircraft (nose up/down)
Honeywell Laserref	IRS Yaw Rate	[degree/sec]	0.1or 1%	0.015	Rate of heading angle
Honeywell Laserref	IRS Roll Rate	[degree/sec]	0.1or 1%	0.015	Rate of roll angle
Honeywell Laserref	IRS Pitch Rate	[degree/sec]	0.1or 1%	0.015	Rate of pitch angle
Flight Management Computer	FMC Longitude	[degree (0-360)]	tbd	tbd	Position from flight managment system (combination of GPS and IRS position)
Flight Management Computer	FMC Latitude	[degree (0-180)]	tbd	tbd	Position from flight managment system (combination of GPS and IRS position)