Estimating hydrodynamic parameters of a lake surface cleaning robot using numerical methods

The maneuverability performance prediction is important in design and control of a lake surface cleaning robot (LSCR). An important issue in modeling the robot is to estimate its hydrodynamic parameters. Conventional methods for estimating the parameters include model testing, data regression method, real scale testing, and analytical means. The scale model testing and real scale testing are costly as expensive facilities are needed. The data regression method applies to the robotic ships whose geometric shape is as same as or similar to what stored in the database. This paper proposes a new method based on numerical simulations to estimate the velocity hydrodynamic derivatives of the dynamic model of the LSCR. With the help of the CFD software, we can conduct simulations similar to the constraint scale ship model testing. The forces and momentums of the LSCR under different velocity and drifting angle conditions can be obtained from the simulations. Then the hydrodynamic derivatives are estimated using the forces and momentums. Compared with the constraint scale model testing, the proposed method is more convenient and cost-effective.