Enhanced obstacle-crossing capability of redundantly actuated wheel-legged robot through dynamic stability and actuation pattern analyses

Abstract

The exploration of challenging terrains requires robotic systems with advanced mobility and adaptability. However, maintaining stability and maneuverability while traversing obstacles remains a significant challenge for such systems. Redundantly actuated wheel-legged rovers present a promising solution by introducing additional degrees of actuation, enabling more optimized motion strategies and enhanced overall performance. This paper focuses on enhancing the obstacle-crossing capability of these systems by analyzing the dynamic stability criteria and actuation patterns, using the TAWL rover as demonstration. Firstly, the dynamic models of the TAWL rover’s individual leg and the whole body are established, and the dynamic stability criteria are introduced. Secondly, the actuation patterns of the redundant system are analyzed to identify feasible actuation patterns and evaluate associated energy consumption. Thirdly, enhanced obstacle-crossing strategies are proposed, consisting of two components: increasing the rover’s maximum obstacle-crossing height and improving its stability when traversing specific obstacles. Finally, the proposed method is validated on the TAWL rover. The results demonstrate that the proposed method enables the rover to achieve maximum obstacle-crossing height and exhibit superior stability margin while traversing obstacles.