% The continuum of linearized models of a missile is modelled as % an LFR-object % % Symbolic approach. % Load numerical data missiledata % Define symbolic objects syms Al q Ma dp % Build differential equations Cz = z3*Al^3 + z2*Al^2 + z1*( 2 -(1/3)*Ma)*Al + z0*dp; Cm = m3*Al^3 + m2*Al^2 + m1*(-7 +(8/3)*Ma)*Al + m0*dp; A1 = q+K1*Ma*Cz*(1-Al^2/2);%+Al^4/24); A2 = K2*Ma^2*Cm; C1 = K3*Ma^2*Cz; F = [A1;A2;C1]; % Differentiate for obtaining linearized models ABCD = [diff(F,'Al') diff(F,'q') diff(F,'dp')]; % PLug equilibrium surface into ABCD dp = -(m3*Al^3 + m2*Al^2 + m1*(-7 +(8/3)*Ma)*Al)/m0; ABCD = eval(ABCD); % Realization ABCD = symtreed(ABCD); % Input/output form sys = abcd2lfr(ABCD,2); % Order reduction after realization sys = minlfr(sys,1000*eps); % Normalisation sys = normalizelfr(sys,{'Al','Ma'},[0 2],[0.24 4]); sys_sym = sys;