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RK4 (Runge-Kutta) Help file
%script RK4()
%RK4.m
% Given the transfer function 0.0165/(s^2+0.186s+0.0165) solving the differential
% equation, this routine returns the values at the next time step
% In this version we use the fourth-order Runge-Kutta method
% to integrate.
%
% integrate to get current state
% dt=time increment
% Theta = pitch angle
% deltaE = elevator angle
%
This function is free to copy and distribute for educational purposes as long
%
as this notice is included. No guarantee expressed or otherwise is made of the
%
accuracy of the code.
%
Eric Vinande/Doug Hiranaka 4-98
%
Copyright (c) 1998 by Cal Poly San Luis Obispo
hold on;
%clear;
DegToRad = 0.01745329;
%***** begin inputs *****
K = 1.0;
wn = 0.12845;
zeta = 0.5;
deltaE = 1.0;
dt = 0.5;
tFinal = 100;
%***** end of inputs *****
%***** coefficients for Runge-Kutta method *****
a = 2.0*zeta*wn;
b = wn^2.0;
c = wn^2.0;
Theta(1)=0;
z(1)=0;
t = dt;
Time(1)=0;
index=2;
while t <= tFinal;
k1=dt*z(index-1);
l1=dt*(-a*(z(index-1))-b*(Theta(index-1))+K*c*deltaE);
k2=dt*(z(index-1)+l1/2.0);
l2=dt*(-a*(z(index-1)+l1/2.0)-b*(Theta(index-1)+k1/2.0)+K*c*deltaE);
k3=dt*(z(index-1)+l2/2.0);
l3=dt*(-a*(z(index-1)+l2/2.0)-b*(Theta(index-1)+k2/2.0)+K*c*deltaE);
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