Search and rescue (SAR) robots are required to quickly traverse terrain and perform high-force rescue tasks, necessitating both terrain adaptability and controlled high-force output. Few platforms exist today for SAR, and fewer still have the ability to cover both tasks of terrain adaptability and high-force output when performing extraction. While legged robots offer significant ability to traverse uneven terrain, they typically are unable to incorporate mechanisms that provide variable high-force outputs, unlike traditional wheel-based drive trains. This work introduces a novel concept for a dynamically extensible and retractable robot leg. Leveraging a dynamically extensible and retractable five-bar linkage design, it allows for mechanically switching between height-advantaged and force-advantaged configurations via a geometric transformation. A testbed evaluated leg performance across linkage geometries and operating modes, with empirical and analytical analyses conducted on stride length, force output, and stability. The results demonstrate that the morphing leg offers a promising path toward SAR robots that can both navigate terrain quickly and perform rescue tasks effectively.

翻译：搜救机器人需快速穿越地形并执行高负载救援任务，这要求其兼具地形适应性与可控的高力输出能力。目前适用于搜救的机器人平台较少，而能在执行救援任务时兼顾地形适应与高力输出的平台更为罕见。尽管足式机器人在崎岖地形通行方面具有显著优势，但与传统轮式驱动系统不同，它们通常难以集成可提供可变高力输出的机构。本研究提出一种动态可伸缩机器人腿部的新颖设计概念。该设计采用动态可伸缩的五连杆机构，通过几何变换实现机械结构在高度优势模式与力学优势模式间的切换。通过实验平台评估了不同连杆几何构型与工作模式下的腿部性能，并对步幅长度、力输出及稳定性进行了实证与理论分析。结果表明，这种可变形腿部为开发既能快速穿越地形又能高效执行救援任务的搜救机器人提供了可行路径。