plot(cos(0:.1:2*pi),sin(0:.1:2*pi),-0.4+0.1*cos(0:0.1:2*pi),...
   0.2+0.1*sin(0:0.1:2*pi),...
   0.4+0.1*cos(0:0.1:2*pi),0.2+0.1*sin(0:0.1:2*pi),...
   0.6*cos(0:.1:pi),-0.1-0.4*sin(0:.1:pi))

t=0:.1:2*pi; plot(cos(t),sin(t));
line(-0.4+0.1*cos(t),0.2+0.1*sin(t));
line(0.4+0.1*cos(t),0.2+0.1*sin(t));
t=0:.1:pi; line(0.6*cos(t),-0.2-0.4*sin(t));

disp('PID\nController')

image(imread('tiantan.jpg'))