2
Experiment # 4.
Objectives:
1. Longitudinal linearized equations of motion of Boeing 747.
2. Determine the response of Boeing at particular Roll Angle using
simulation.
3. Determine the response of Boeing at particular elevation using simulation.
Background:
The Boeing 747 is a large wide body transport jet. The linearized
equations of (rigid-body) motion for the Boeing 747 are of 8th order but are
separated into two 4th order sets representing the perturbations in longitudinal (U,
W,
, and q) and lateral motion (
pandr,,,,
). The longitudinal motion consists
of axial (X), vertical (Z), and pitching (
, q) motion, while the lateral motion
consists of rolling (
, p), yawing (r,
) movement. The side-slip angle
is a
measure of the direction of the nose of the airplane. The elevator control
surfaces and the throttle affect the longitudinal motion, whereas the aileron and
rudder primarily lateral motion. Although there is a small amount of coupling of
lateral motion into longitudinal motion, this is usually ignored, so the equations of
motion are treated as two decoupled fourth-order sets of designing the control, or
stability augmentation, for the aircraft.
One of the pilot’s many tasks is to hold a specific altitude. As an aid to
keeping aircraft from colliding, those craft on an easterly path are required to be
on an odd multiple of 1000 ft and those on a westerly path on an even multiple of
1000 ft. Therefore, the pilot needs to be able to hold the altitude to less then a
hundred feet. A well-trained, attentive pilot can easily accomplish this task
manually to
50 ft, and air-traffic controllers expect pilots to maintain this kind of
tolerance. However, because this task requires the pilot to be fairly diligent,
sophisticated aircraft often have an altitude-hold auto-pilot to lessen the pilot’s
work.
docsity.com
