With Proximity Servoing towards Safe Human-Robot-Interaction

In this paper, we present a serial kinematic robot manipulator equipped with multimodal proximity sensing modules not only on the TCP but distributed on the robot's surface. The combination of close distance proximity information from capacitive and time-of-flight (ToF) measurements allows the robot to perform safe reflex-like and collision-free motions in a changing environment, e.g. where humans and robots share the same workspace. Our methods rely on proximity data and combine different strategies to calculate orthogonal avoidance motions. These motions are instantaneous optimal and are fed directly into the motion controller (proximity servoing). The strategies are prioritized, firstly to avoid collision and then secondly to maintain the task motion if kinematic redundancy is available. The motion is then optimized for avoidance, best manipulability, and smallest end-effector velocity deviation. We compare our methods with common force field based methods.