X = zeros(4,1);
dX = zeros(4,1);
Ref = 1;
dt = 0.01;
U = 0;
t = 0;
Kx = [-7.0711  -94.1403   -9.6657  -22.8618];
Kr = -7.0711;
while(t < 100)
 Ref = sign(sin(0.5*t));
 U = Kr*Ref - Kx*X;
 dX = CartDynamics(X, U);
 X = X + dX * dt;
 t = t + dt;
 CartDisplay(X, Ref);
 end