What is considered safe for a robot operator during physical human-robot collaboration (HRC) is specified in corresponding HRC standards (e.g., the European ISO/TS 15066). The regime that allows collisions between the moving robot and the operator, called Power and Force Limiting (PFL), restricts the permissible contact forces. Using the same fixed contact thresholds on the entire robot surface results in significant and unnecessary productivity losses, as the robot needs to stop even when impact forces are within limits. Here we present a framework for setting the protective skin thresholds individually for different parts of the robot body and dynamically on the fly, based on the effective mass of each robot link and the link velocity. We perform experiments on a 6-axis collaborative robot arm (UR10e) completely covered with a sensitive skin (AIRSKIN) consisting of eleven individual pads. On a mock pick-and-place scenario with both transient and quasi-static collisions, we demonstrate how skin sensitivity influences the task performance and exerted force. We show an increase in productivity of almost 50% from the most conservative setting of collision thresholds to the most adaptive setting, while ensuring safety for human operators. The method is applicable to any robot for which the effective mass can be calculated.

翻译：在物理人机协作（HRC）中，关于机器人操作员安全性的规定由相应的HRC标准（如欧洲ISO/TS 15066）所定义。允许移动机器人与操作员发生碰撞的机制——功率与力限制（PFL）——对允许的接触力施加了限制。在整个机器人表面使用相同的固定接触阈值会导致显著且不必要的生产效率损失，因为即使冲击力在限制范围内，机器人也需要停止。本文提出一种框架，能够根据每个机器人连杆的有效质量和连杆速度，为机器人身体的不同部位单独且动态地设置保护性皮肤阈值。我们在一个完全覆盖敏感皮肤（AIRSKIN）的六轴协作机器人手臂（UR10e）上进行了实验，该皮肤由十一个独立垫片组成。通过一个包含瞬态和准静态碰撞的模拟拾取放置场景，我们展示了皮肤灵敏度如何影响任务性能和施加的力。结果表明，从最保守的碰撞阈值设置到最具适应性的设置，生产效率提高了近50%，同时确保了人类操作员的安全。该方法适用于任何可以计算有效质量的机器人。