Development of 2DOF actuation slosh rig : a novel mechatronic system

Sloshing of liquid in a tank is important in several areas including launch vehicles carrying liquid fuel in space application, ships, and liquid cargo carriages. Hence modeling and characterization of nonlinear slosh dynamics is critical for study of dynamics of these systems. Additionally control of sloshing liquid offers a challenging problem of control of underactuated systems. To study slosh dynamics, develop useful identification schemes, and design and verify slosh control algorithms, a new 2DOF actuation slosh rig is reported in this paper considering the fact that most of the times the liquid tanks are subjected to linear as well as pitching excitation. The paper discusses mechatronic design and several advantages offered by the new design. Furthermore, a mathematical model of the rig is developed using Lagrange formulation assuming two-pendulum model for slosh. Slosh parameter identification with the rig is demonstrated in pitching and linear excitation cases. Nonlinear parameter identification schemes developed using simplified version of rig model are used for the purpose. Further results on compensation of slosh and rotary slosh phenomena are presented. Thus the proposed rig is ideal tool for study, identification, and control of slosh phenomena