Abstract
KRISO(Korea Research Institute of Ships & Ocean Engineering) designed and manufactured a pilot mining robot called "MineRo" in 2012. MineRo is composed of four track modules. In general, much time and money are needed for deep-sea tests. Therefore, a numerical analysis to predict the dynamic behaviors has to be performed before a deep-sea test. In the numerical analysis, the information about the mining robot and soil properties are the most important factors to analyze the driving performance and dynamic response of MineRo. A terra-mechanics model of extremely cohesive soft soil is implemented in the form of the relationships between the normal pressure and sinkage, and between the shear stress and shear displacement. It is possible to acquire information about MineRo from the CAD model in the design phase. The Wong model is applied to the terra-mechanics model. This model is necessary to acquire many soil coefficients for a numerical analysis. However, in soil testing, the amount of soil property data obtained is limited. Moreover, it is difficult to analyze all of the cases for the many soil coefficients. In this paper, the dynamic behaviors of MineRo are analyzed according to the driving velocity, steering ratio, and variable extremely cohesive soft soil properties using a table of orthogonal arrays. The dynamic responses of MineRo are the turning radius, sinkage, and slip ratio. The relationships between the dynamic responses and variable soil properties are derived for MineRo.
