function y=optfpid_fun(x)
assignin('base','Kp',x(1)); assignin('base','Ki',x(2));
assignin('base','Kd',x(3));
assignin('base','mu0',x(4));
try
[~,~,y_out]=sim('c9mfpidd',[0,20]);
catch, y_out=1e100; end
y=y_out(end,1); disp([x(:).' y])
end