Optimal Command Shaping Design for a Liquid Slosh Suppression in Overhead Crane Systems

In many industries, liquid container transport is carried out by an overhead traveling crane. The operation of crane transferring liquid slosh containers required both operator experience and an automated control system. The goal of this research is to move the liquid inside a container in a short time and less spill for process effectiveness and safety. For controller design, a nonlinear mathematical model is developed to represent the actual system. A cost-effective, smooth continuous command shaper is presented to suppress sloshing vibration. The designed shaper is a multisine-wave function with adjustable and independent time maneuvering used to design the acceleration profile. The coefficients that control the shaper profile are obtained by solving a nonlinear constrained optimization problem using particle swarm algorithm. Simulation and experimental comparative results proved that the proposed command shaper can reduce transient peak slosh amplitudes. Moreover, it can simultaneously cancel both residual sloshing vibrations and container oscillations at the end of the transportation process which cannot be achieved using conventional zero-vibration (ZV), zero-vibration derivative (ZVD), and jerk-limited shaper. Furthermore, sensitivity analysis demonstrates that the proposed command shaper is robust to model parameters variation such as liquid depth, suspension length, or moving distance of the trolley.