clear all; clc; close all;
% CONTROLADOR on - off

% ejemplo: tanque de agua (linealizado)
% dh/dt = qin/A - b/A*h

A = 1; % m2
b = 1; % m2/h
hr = 0.5; %  m
d = 0.1; % m

h0 = 0.5; % m
q0 = 1; % m3/h
dt = 0.001; % h
t = 0:dt:5; % h

h(1) = h0; qin = q0; qi(1) = qin;
h(2) = h(1) + qin/A*dt - b/A*h(1)*dt; qi(2) = qin;
for i = 3:length(t)
    if h(i-1)-h(i-2) > 0 & h(i-1) >= h0 + d
      qin = 0;
    end
    if h(i-1)-h(i-2) < 0 & h(i-1) <= h0 - d 
      qin = q0;
    end
    h(i) = h(i-1) + qin/A*dt - b/A*h(i-1)*dt;
    qi(i) = qin;
end

subplot(211)
plot(t,h)
xlabel('t (h)'); ylabel('h (m)')
subplot(212)
plot(t,qi)
axis([0,t(end),-0.2,q0*1.2])
xlabel('t (h)');ylabel('qin (m3/h)')