function [name,T,y,u,ye,ue,J] = ppp_ex15 (ReturnName)
## usage: ppp_ex15 ()
##
## PPP example - an unstable, nmp siso system
## $Id$
## Example name
name = "Linear unstable non-minimum phase third order system - intermittent control";
if nargin>0
return
endif
## System - unstable
A = [3 -3 1
1 0 0
0 1 0];
B = [10
0
0];
C = [0 -0.5 1];
D = 0;
[n_x,n_u,n_y] = abcddim(A,B,C,D);
## Setpoint
A_w = ppp_aug(0,[]);
## Controller
t =[4.0:0.01:5.0]; # Optimisation horizon
dt = t(2)-t(1);
A_u = ppp_aug(laguerre_matrix(3,2.0), A_w);
Q = 1; # Weight
##Simulate
W = 1; # Setpoint
x_0 = zeros(n_x,1); # Initial state
## Closed-loop intermittent solution
Delta_ol = 0.5 # Intermittent time
disp("Intermittent control simulation");
R=1;P=0;
[T,y,u] = ppp_qp_sim (A,B,C,D,A_u,A_w,t,Q,R,P, \
[],[],[],[], \
[],[],[],[],W,x_0,Delta_ol);
size(T)
## Exact closed-loop
disp("Exact closed-loop");
[k_x,k_w] = ppp_lin (A,B,C,D,A_u,A_w,t,Q)
[ye,Xe] = ppp_sm2sr(A-B*k_x, B, C, D, T, k_w*W, x_0); # Compute Closed-loop control
ue = k_w*ones(size(T))*W - k_x*Xe;
title("y and u, exact and intermittent");
xlabel("t");
grid;
plot(T,y,"1;y (intermittent);", T,u,"2;u (intermittent);",\
T,ye,"3;y (exact);", T,ue,"4;u (exact);");
endfunction