Simulink Control Design™ - MathWorks

(4.) csthl20_trim/beta (8)

spec: none

(5.) csthl20_trim/Mach (9)

spec: none

(6.) csthl20_trim/Ax,Ay,Az (10-12)

spec: none

spec: none

spec: none

Specify the equilibrium conditions for each orientation of the airframe. To do this:

• Specify the orientation by fixing the outputs alpha and beta to their desired values.


• Specify the airframe speed by fixing the Mach output to 0.6.


• Mark the angular rates p,q,r as steady.


• Mark the velocities vb and wb as steady.

for ct=1:40

% Specify alpha angle

opspec(ct).Outputs(3).y = alpha(ct);

opspec(ct).Outputs(3).Known = true;

% Specify beta angle

opspec(ct).Outputs(4).y = beta(ct);

opspec(ct).Outputs(4).Known = true;

% Specify Mach speed

opspec(ct).Outputs(5).y = Mach;

opspec(ct).Outputs(5).Known = true;

% Mark p,q,r as steady

opspec(ct).States(2).SteadyState = true(3,1);

% Mark vb,wb as steady

opspec(ct).States(3).SteadyState = [false;true;true];

% (phi,theta,psi) and (Xe,Ye,Ze) are not steady

opspec(ct).States(1).SteadyState = false(3,1);

opspec(ct).States(4).SteadyState = false(3,1);

end

To fully characterize the trim condition, also

• Set p=0 to prevent rolling.


• Set the roll/pitch/yaw angles (phi,theta,psi) to (0,alpha,beta) to align the wind and
  earth frames.

11 Gain-Scheduled Controllers