Life Extension: An Autonomous Docking Station for Recharging Quadrupedal Robots

Abstract

In this paper we describe the design of a fully autonomous docking stationfor the quadrupedal robot ANYmal. The autonomous recharging of mobile robotsis a crucial feature when long-term autonomy is expected or human intervention isnot possible. This is the case when a robot is used in environments that create apotential hazard to humans such as the inspection of oil rig platforms. If operated insuch explosive environments, machines are usually required to be frequently purgedwith inert gas to avoid ignition through electric sparking (ATEX-P certification).Our docking station allows for recharging of ANYmal’s battery as well as purgingof its main body with gas. We present a robust docking strategy that negotiatespositioning errors of the robot through guiding elements and flexible parts. Thedocking mechanism itself consists of an actuated plug which is inserted into a socketon the robot’s belly for electrical and mechanical connection. The mechanism isdesigned for reliable, sealed and spark-free operation. The system has proven to berobust in a laboratory environment and under realistic conditions.