I cant plot a graph of ode45 function for state space modeling, I don't know how to define.

syms x1 x2 x3 
m=1000;   %Mass in Kg
L=3.5; %length in meters
g=9.81; %gravty term in m/s^2
c=1;  %damping ratio
I=0.5; %inductance 
u=0; %free response
kt=1;    % torque constant 
kb=1;       %back emf constant 
R=1;
A=[-R/I -kb/I 0; kt/m*L^2 -c/m*L^2 -g*0.5/L; 0 1 0];
B=[1/I;0;0];
C=[0 0 m*g*L/2];
D=0;
% x3dot=x2;
% x2dot=(1/m*L^2)*(kt*x1-c*x2-m*g*L*sin(x3));
% x1dot=1/I*(u-R*x1-kb*x2);
% y=m*g*L*sin(x3);
plot(t,y)

[Jan]

Please read the documentation of ODE45, where you find some examples:

doc ode45 

For a numerical integration you do not need symbolic variables, but a function to calculate the derivative and an initial value.

Answer 1

[Sai]

Hi Jasmin,

Please refer to the follwing link on how to solve state space equation by ODE45

• https://in.mathworks.com/matlabcentral/answers/146782-solve-state-space-equation-by-ode45

For more information on ode45, please refer to the following documentation link

• https://in.mathworks.com/help/matlab/ref/ode45.html