Modeling and simulation of underwater walking vehicles

Conceptually, the advantage of walking instead of rolling over soft ground or rough terrain is that less energy is expended in compacting the soil. In certain underwater applications, a semi-stationary platform is necessary to perform the operation, for example, in pipeline maintenance and ocean mining. As discussed in a companion paper, a walking machine can provide not only a sturdy base for these types of application but also has the ability to move around efficiently. In this paper, it is intended to address the ensuing problem of mathematical modeling and simulation of an underwater vehicle with mechanical legs walking on a flat seabed. A mathematical model for the underwater walking vehicle has been developed. In addition to the problems associated with leg locomotion, this model also accounted for the buoyancy effects, hydrodynamic lift and drag, fluid-structure interactions, and ground effects encountered in underwater applications. Based on this model, a computer simulation program with interactive graphics display was written and the results are presented in this paper.