%%%  II order system - define the parameters and run the relative simulink file 

%%% define the parameters for the mass-spring-damper system

m=1; % Kg
k=4; %N/m
b=4; % N/m*s


% implement in Simulink the y_ddot +a1*y_dot+a0*y=b0*u 
a0=k/m;
a1=b/m;
b0=1/m;


%  % define the tf
% W=1/m/(s^2+ b/m*s + k/m); 

%%% run the simulink file
sim('ex_II_ord_sys')

%%% and then plot y and ydot (the speed)
%%% simulink returns the time vector and 
%%% the variables defined by the block simout
figure
hold on
grid on

plot(tout, simout.data,'linewidth',2)

xlabel('time')
ylabel('y and dy/dt')
legend('y','dy/dt')