End-effector airbags to accelerate human-robot collaboration

Abstract

A fundamental problem in human-robot collaboration is to ensure safety for humans being located in the workspace of the robot. Several new robots, referred to as collaborative robots, are pushing into the market. Most of these so-called co-bots have similar properties. They are small, lightweight and designed with big roundings to ensure safety in the case of a collision with a human. Equipped with torque sensors, external torque observers, tactile skins, etc., they are able to stop the robot when an emergency occurs. While developing more and more co-bots, the main focus lies on the robot itself. But to make a robot deployable, a special tool for a defined task is needed. These tools are often sharp-edged and dangerous in case of a collision with a human. In this paper we present a new safety module for robots to ensure safety for different tools in collaborative tasks. This module, filled with air pressure during the robot motion, covers mounted tools and carried workpieces. In case of a non or very slow moving robot, the safety module is able to pull back and the tool is uncovered. In our experiments we found out that we can increase the velocity up to 1 m/s while satisfying the requirements of the ISO/TS 15066 and retain the full functionality of the tool.

A review of the challenges in mobile manipulation: systems design and RoboCup challenges

“…Apart from the application of ISO/TS 15066 [56], more effort is necessary in the definition of standard testing methods and standardized test setup and hardware. Currently available developments which enable safe human robot co-working are airbags systems [90], robotic skins [15,53], but also control strategies for intuitive hand guidance [92] based on force/torque-sensing.…”

Robot Arms Capable of Safe Physical Human-Robot Interaction

“…Since unsafe tools with sharp edges can cause severe injury to humans, proper measures should be taken for safe collaboration. To achieve this, an airbag-like safety module which builds a cushion between the end-effector and the human in case of collision (Weitschat et al 2017). In this approach, the airbag is inflated during unsafe motions of a robot but is deflated when the full functionality of the tool is required.…”

Safe and Efficient Human-Robot Collaboration Part I: Estimation of Human Arm Motions

“…This is an enormous improvement of the robot performance and leads to an significant improvement of productivity in an industrial human-robot collaboration. To obtain still higher improvements, the follow-up paper "Safe and Efficient Human-Robot Collaboration Part II" will be extended with an integrated real-time path planner derived by [2] and an optimized path to the desired goal by minimizing the time according to min J = t f t0 t 2 dt, considering the projected human arm motion.…”

“…Even with these collision detection mechanisms in place, the velocity of the robot has to be reduced significantly, such that the ISO requirements are satisfied [2]. The underlying motivation for this restriction is that a collision could happen at any time.…”