ABSTRACT
The need for fast maneuvering and accurate positioning of flexible structures
poses a control challenge. The inherent flexibility in these lightly damped systems
creates large undesirable residual vibrations in response to rapid disturbances. Several
control approaches have been proposed to tackle this class of problems, of which the
input shaping technique is appealing in many aspects.
While input shaping has been widely investigated to attenuate residual vibrations in
flexible structures, less attention was granted to expand its viability in further
applications. The aim of this work is to develop a methodology for applying input
shaping techniques to suppress sloshing effects in open moving containers to facilitate
safe and fast point-to-point movements. The liquid behavior is modeled using finite
element analysis. The input shaper parameters are optimized to find the commands
that would result in minimum residual vibration. Other objectives, such as improved
robustness, and motion constraints such as deflection limiting are also addressed in the
optimization scheme. Numerical results are verified on an experimental setup
consisting of a small motor-driven water tank undergoing rectilinear motion, while
measuring both the tank motion and free surface displacement of the water. The
results obtained suggest that input shaping is an effective method for suppressing
residual liquid vibrations.