Efficient Control of Motion of the Carrying Body for Different Approximate Determinations of the Force Reaction of the Fluid

The problem of reducing the effect of the mobility of free surface fluid on the motion of the carrying structure is considered. For the mathematical description of the problem, a variational approach with elements of nonlinear mechanics and ideas of the method of modal decomposition of system variables is used. This approach makes it possible to determine, in an analytical form, the internal forces of interaction of the fluid with the tank walls. The proposed control method is based on the idea of compensating the interaction of the fluid with the structure by including this force in the special control. This approach is tested against various control problems (for short-term and harmonic perturbations). The capabilities of the method are tested using different approximate determinations of the force reaction of the fluid. The results show that in the case of a simplified (linear) or single-term determination of the force reaction of the fluid, this method gives significant errors at the initial stage of motion, but later these deviations decrease substantially and, as a result, the effect of fluid mobility on the carrying structure is practically eliminated.