Modeling for the Crabster leg with hydrodynamics force

The KRISO (Korea Research Institute of Ships & Ocean engineering) developed the Crabster which is an underwater walking robot with six legs in 2013. This robot is operated on the seabed with high tide and high turbidity environments which is unknown environments. This paper deals with modeling of the Crabster leg with hydrodynamics force for active control and feedback control. Joints of friction and buoyancy model are derived with experiments. Motor currents are used to the modeling process. Finally, the derived model is verified with walking pattern data of the Crabster.