Design and Development of a Novel 2DOF Actuation Slosh Rig

Sloshing of liquid in a tank is critical in several areas, including launch vehicles carrying liquid fuel, satellites, industrial packaging of liquids, systems handling molten metal, and so on. Hence modeling, characterization, and control of nonlinear slosh phenomena are important in these applications. 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 these tanks are subjected to linear as well as pitching excitation/control inputs. The paper discusses mechatronic design and several advantages that the new design offers. A slosh phenomenon of beating observed when both lateral and pitching excitations are provided is simulated using a model based on pendulum approximation to slosh and is further verified in experiments. The results confirm that the effects of both excitations together can be detrimental against separate excitations of the same amplitude. Moreover, slosh compensation in open loop is demonstrated by giving excitation in pitching and developing a compensatory input in the lateral direction. Furthermore, active slosh control strategy is developed and its effectiveness is demonstrated with control in translation and disturbance in pitching. Thus the proposed rig is an ideal tool for the study, identification, and control development of slosh in the presence of two excitations/inputs.