Research on the Design and Experiment for Obstacle-Crossing Capability of a Wheeled-Claw Deformable Mobile Platform With Large Expansion Ratio

To enhance adaptability and obstacle-crossing performance in unstructured environments, this study proposes a large-expansion-ratio deformable mobile platform, referred to as the “Wheel–Claw Climber,” which is based on spatial folding and linkage deformation mechanisms. The platform incorporates a radially expandable deformable wheel with a maximum expansion ratio of 2.72, substantially exceeding the existing benchmark of 2.4. The “Wheel–Claw Climber” operates in three distinct configurations—wheel, claw, and intermediate—enabling adaptation to diverse terrains. An obstacle-crossing model is established, and the maximum obstacle-crossing height is determined to be 4.5R, representing a 27.7% improvement over current designs and demonstrating superior obstacle-surmounting capability. Furthermore, a cross-slope traversal strategy is proposed, whereby deformation and expansion of the low-side wheel relative to the high-side wheel increase passability and stability by 31.1% and 21.65%, respectively, on the same slope. Experimental validation confirms that the Wheel–Claw Climber can seamlessly transition between wheel and claw modes. At a wheel rotation speed of 1 rad/s, the platform achieves a maximum obstacle-crossing height of 550 mm, with a 100% success rate for obstacles below 450 mm. Overall, the deformable wheel architecture and experimental findings provide new insights for the design and development of next-generation mobile platforms.