Enhancing open-loop performance of overhead cranes by a simple energy-based hidden control loop

A new simple approach is proposed that improves the transient performance of an overhead crane. Particularly, the open-loop operation is substantially improved by adding a simple nonlinear hidden control-loop that needs measurements of only the carrier and angle velocities. This controller acts as a complementary part of the open-loop operation and it is implemented by a coupled-dissipation feedback term. Using energy-based techniques we prove that the proposed hidden controller increases the swing damping and the passivity of the system. Simulation tests under conventional open-loop operation indicate a decisive suppression of the angle oscillations and verify the effectiveness of the proposed scheme.