Optimal leg-sequence selection for an underwater hexapod robot in the presence of slopes and external forces

This work proposes a novel optimal leg sequence selection method for hexapod robots, in terms of robot stability, and for a combination of various gaits, motion modes and sloped terrains. The method finds the most stable leg sequence for the required gait. If no such gait exists, the fastest stable gait is chosen and the most stable leg sequence for this gait is selected. The method can be based on any stability criterion, with the Force-Angle Stability Margin that takes into account the external forces effect, being the one used here. Results show that the proposed method observes instabilities accurately and selects the appropriate leg sequence for stability increase, thus offering distinct advantages when external forces prevail.