Development of universal vacuum gripper for wall-climbing robot

Task performed at a height, such as wall inspections are one of the dangerous tasks for humans. Thus, robotic technology for safety inspection is required. This research focuses on developing robots to climb vertical walls with flat and uneven surfaces, e.g. concrete, tile and riveted structure. To have wall-climbing capability, climbing robots use vacuum pads, claws, magnets, intermolecular force, and adhesive. However, each of these approaches has disadvantages. To achieve wall climbing on an uneven surface without scratching and staining, we have developed a novel vacuum pad named the Universal Vacuum Gripper (UVG), which is based on the Universal Gripper (UG). The UG is a robot hand using jamming transition of coffee powder inside a balloon to grip uneven material. The UVG is a vacuum pad with a deformable skirt based on the UG. If the skirt shape is deformed in accordance with the contact surface, air leaks can be avoided. Moreover, the deformed skirt can be stiffened, thereby working as a gripper. Here, we evaluate the proposed gripper, having both grasping and adhesion force. We also develop a wall-climbing robot with UVGs, and evaluate its performance on uneven surfaces under real-world conditions.

高空作业（如墙体巡检）是人类面临的高危作业任务之一，因此亟需研发用于安全巡检的机器人技术。本研究聚焦于研发可在平整及凹凸垂直壁面上攀爬的机器人。为实现壁面攀爬能力，主流攀爬机器人多采用真空吸盘、爪钩、磁吸附、分子间作用力以及粘合剂等吸附方案，但各类方案均存在各自的技术缺陷。为实现在凹凸表面上无划伤、无污染的壁面攀爬作业，我们基于通用夹具（Universal Gripper, UG）研发了一款新型真空吸盘，命名为通用真空夹具（Universal Vacuum Gripper, UVG）。通用夹具（UG）是一种借助气球内部咖啡粉的颗粒阻塞相变（jamming transition）来夹持凹凸材质的机器人手部执行机构。通用真空夹具（UVG）是一款基于通用夹具（UG）、带有可变形裙边的真空吸盘。当裙边形状与接触面适配时，可有效避免空气泄漏；同时，变形后的裙边可被固化，进而兼具夹持功能。本文对所提出的兼具抓取力与吸附力的夹具进行了性能评估，并研发了搭载通用真空夹具（UVG）的壁面攀爬机器人，在真实工况下针对凹凸表面的攀爬性能开展了实验验证。