Simulink Control Design™ - MathWorks

To analyze the airframe dynamics, trim the airframe for and. The trim

condition corresponds to zero normal acceleration and pitching moment ( and steady).

Use findop to compute the corresponding closed-loop operating condition. Note that we

added a "delta trim" input port so that findop can adjust the fin deflection to produce the

desired equilibrium of forces and moments.

opspec = operspec('rct_airframe1');

% Specify trim condition

% Xe,Ze: known, not steady

opspec.States(1).Known = [1;1];

opspec.States(1).SteadyState = [0;0];

% u,w: known, w steady

opspec.States(3).Known = [1 1];

opspec.States(3).SteadyState = [0 1];

% theta: known, not steady

opspec.States(2).Known = 1;

opspec.States(2).SteadyState = 0;

% q: unknown, steady

opspec.States(4).Known = 0;

opspec.States(4).SteadyState = 1;

% integrator states unknown, not steady

opspec.States(5).SteadyState = 0;

opspec.States(6).SteadyState = 0;

op = findop('rct_airframe1',opspec);

Operating point search report:

---------------------------------

Operating point search report for the Model rct_airframe1.

(Time-Varying Components Evaluated at time t=0)

Operating point specifications were successfully met.

States:

----------

(1.) rct_airframe1/Airframe Model/Aerodynamics & Equations of Motion/ Equations of Motion (Body Axes)/Position

x: 0 dx: 984

x: -3.05e+03 dx: 0

(2.) rct_airframe1/Airframe Model/Aerodynamics & Equations of Motion/ Equations of Motion (Body Axes)/Theta

x: 0 dx: -0.00972

(3.) rct_airframe1/Airframe Model/Aerodynamics & Equations of Motion/ Equations of Motion (Body Axes)/U,w

x: 984 dx: 22.7

13 Control System Tuning Examples