Legged locomotion benefits from embodied sensing, where perception emerges from the physical interaction between body and environment. We present a soft-surfaced, vision-based tactile foot sensor that endows a bipedal robot with a skin-like deformable layer that captures contact deformations optically, turning foot-ground interactions into rich haptic signals. From a contact image stream, our method estimates contact pose (position and orientation), visualizes shear, computes center of pressure (CoP), classifies terrain, and detects geometric features of the contact patch. We validate these capabilities on a tilting platform and in visually obscured conditions, showing that foot-borne tactile feedback improves balance control and terrain awareness beyond proprioception alone. These findings suggest that integrating tactile perception into legged robot feet improves stability, adaptability, and environmental awareness, offering a promising direction toward more compliant and intelligent locomotion systems. For the supplementary video, please visit: https://youtu.be/ceJiy9q_2Aw

翻译：腿式运动得益于具身感知，即感知源于身体与环境之间的物理交互。我们提出一种软表面视觉触觉足部传感器，为双足机器人赋予一层类似皮肤的柔性变形层，通过光学方式捕捉接触变形，将足地交互转化为丰富的触觉信号。基于接触图像流，我们的方法能够估计接触位姿（位置与朝向）、可视化剪切力、计算压力中心、对地形进行分类，并检测接触区域的几何特征。我们在倾斜平台及视觉遮蔽条件下验证了这些功能，结果表明，相较于仅依赖本体感知，足部触觉反馈能显著提升平衡控制与地形感知能力。这些发现表明，将触觉感知集成到腿式机器人足部，能够提高其稳定性、适应性和环境感知能力，为开发更具顺应性与智能性的运动系统提供了一个有前景的方向。补充视频请访问：https://youtu.be/ceJiy9q_2Aw