This paper presents SCALER, a versatile free-climbing multi-limbed robot that is designed to achieve tightly coupled simultaneous locomotion and dexterous grasping. Although existing quadruped-limbed robots have shown impressive dexterous skills such as object manipulation, it is essential to balance power-intensive locomotion and dexterous grasping capabilities. We design a torso linkage and a parallel-serial limb to meet such conflicting skills that pose unique challenges in the hardware designs. SCALER employs underactuated two-fingered GOAT grippers that can mechanically adapt and offer 7 modes of grasping, enabling SCALER to traverse extreme terrains with multi-modal grasping strategies. We study the whole-body approach, where SCALER uses its body and limbs to generate additional forces for stable grasping with environments, further enhancing versatility. Furthermore, we improve the GOAT gripper actuation speed to realize more dynamic climbing in a closed-loop control fashion. With these proposed technologies, SCALER can traverse vertical, overhang, upside-down, slippery terrains, and bouldering walls with non-convex-shaped climbing holds under the Earth's gravity.

翻译：本文介绍了SCALER——一种多功能自由攀登多肢体机器人，旨在实现紧密耦合的同步运动与灵巧抓取。尽管现有四足肢体机器人已展现出物体操作等令人瞩目的灵巧技能，但平衡高能耗运动与灵巧抓取能力至关重要。针对硬件设计中由这类相互冲突的技能带来的独特挑战，我们设计了躯干连杆与并联-串联混合肢体。SCALER采用欠驱动双指GOAT夹爪，该夹爪可机械自适应并提供7种抓取模式，使SCALER能够通过多模态抓取策略穿越极端地形。我们研究了全身协同方法——SCALER利用躯干与肢体产生额外力以实现与环境间的稳定抓取，进一步增强了多功能性。此外，我们提升了GOAT夹爪的驱动速度，以闭环控制方式实现更具动态性的攀爬。借助上述技术，SCALER能够在地球重力环境下穿越包含垂直、悬垂、倒置、湿滑地形以及非凸形攀岩支点的抱石墙。