Page 583 - Mechatronics with Experiments

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JWST499-c07
JWST499-Cetinkunt
ELECTROHYDRAULIC MOTION CONTROL SYSTEMS 569
z_out = z’ ;
u_out = 0;
for (t=t_0: t_sample:t_f)
t_span=[t,t+t_sample] ;
[t,z1] = ode45(‘cyl_flex’,t_span, z);
[m,n]=size(z1);
z(:)=z1(m,:);
if z(7)<0.0 % Pressure can not be negative.
z(7)=0.0;
end
if z(8)<0.0
z(8)=0.0;
end

if t<2.0 % Load force for plotting purposes.
F_load= 0.0 ;
elseif (t>= 2.0&t<6.0)
F_load = 10000 ;
else
F_load = 0.0 ;
end
u(1) = F_load ;

z_out=[z_out ; z’] ;
u_out=[u_out ; u];
end
t_out=t_0:t_sample:t_f+t_sample;
t_out = t_out’ ;
subplot(321) ; plot(t_out,z_out(:,1)); title(‘y1’); grid on;
subplot(323) ; plot(t_out,z_out(:,2)); title(‘y2’); grid on;
subplot(325) ; plot(t_out,z_out(:,3)); title(‘y3’); grid on;
subplot(322) ; plot(t_out,z_out(:,7)); title(‘Phe (Head end pressure)’);
grid on;
subplot(324) ; plot(t_out,z_out(:,8)); title(‘Pre (Rod end pressure)’);
grid on;
subplot(326) ; plot(t_out,u_out(:,1)); title(‘Load Force’); grid on;
%%%%%%%%%%%%%%%%%%%%
%%% Filename: cyl_flex.m
function zdot=cyl_flex(t,z)

% Parameters
m1 = 1000 ;
m2 = 100 ;
m3 = 1000 ;
k1 = 1.0E5 ;
k3 = 1.0E6 ;
c1 = 1000 ;
c3 = 1000 ;
beta = 7∗10ˆ8 ;
A_he = 0.01 ;
A_re = 0.005 ;