SYSTEM TDENTIFICATION DEVELOPING AN APPR0 PR1ATE MOOEL OF A YWAMIC SYSTEM US(NG BSERVED DATA COMBINEO WITH: BASIC MECHANICS AND OYNAMICS PR1OR KNOWLEVGE oF RELATIONSKIPS BETWEEN SIGNALS INPUT/OUTPUT MOOELS

Bachelor of Engineering The State University of Buffalo, 2002 Submitted to the Department of Aeronautics and Astronautics in partial fulfillment of the requirements for the degree of Master of Science in Aeronautics and Astronautics

Lateral Autopilots We can stabilize/modify the lateral dynamics using a variety of dif- ferent feedback architectures

INERTIAL SENSoRS MoST, IF NoT ALL, INETIAL SEN SORS MEASURE RATES LINE4R R ANGULAR) 6R ACCELERATIONS WHILE THE RATE INFORMATION IS TYPLCALLY VALIO VER LONG PERIODS of TIME) IT MUST BE INTEGRATED To CET

Complementary Filter(CF) Often, there are cases where you have two different measurement sources for estimating one variable and the noise properties of the two measurements are such that one source gives good information only in low frequency region while the other is good only in high frequency region

Goal: analyze aircraft longitudinal dynamics to determine if the be- havior is acceptable, and if not, then modify it using feed back control Note that we could (and will)work with the full dynamics model but for now, let's focus on the short period approximate model from

State Space Basics State space models are of the form x()= Ax(t)+ Bult) y(t)= Cx(t)+ Dult) with associated transfer function G()=C(sI-A)

mu Xuu+ Xww-mg cos 000+ m(wi-qUo) Zuu+ Zww Ziw+ Zgq-mg sin+ Iyyq Muu+ Mww+ Mww+ Mq+ There is no roll/yaw motion, so=0. Control commands△x,△z,and△ MC have not yet been specified

For general applications in 3D, often need to perform 3 separate rotations to relate our inertial frame to our body frame Especially true for aircraft problems There are many ways to do this set of rotations -with the variations be based on the order of the rotations All would be acceptable

Aircraft Performance Accelerated horizontal flight-balance of forces -Engine thrust TLift(toV)