← Back to Visual Lab
Swing up,
Control playground · 02
Swing up,
catch, balance.
A cart drives two serial links from the hanging equilibrium toward upright. A trajectory-optimized swing-up with feedback tracking does the approach; an upright LQR controller catches the remaining motion.
Live model
Serial double pendulum
Cart position
Link 1 angle
Link 2 angle
Actuator force
What this demonstrates. The first two seconds track one precomputed swing-up trajectory with time-varying feedback; the handoff then uses a local upright LQR law. The controller recovers from the offered ±2 N·s impulses in this model, but it is not a globally stabilizing autonomous swing-up law. With feedback off, modest viscous friction at both joints dissipates the links’ motion toward the hanging configuration.