Life Extension: An Autonomous Docking Station for Recharging Quadrupedal Robots

Abstract

In this paper we describe the design of a fully autonomous docking station for the quadrupedal robot ANYmal. The autonomous recharging of mobile robots is a crucial feature when long-term autonomy is expected or human intervention is not possible. This is the case when a robot is used in environments that create a potential hazard to humans such as the inspection of oil rig platforms. If operated in such explosive environments, machines are usually required to be frequently purged with inert gas to avoid ignition through electric sparking (ATEX-P certification). Our docking station allows for recharging of ANYmal’s battery as well as purging of its main body with gas. We present a robust docking strategy that negotiates positioning errors of the robot through guiding elements and flexible parts. The docking mechanism itself consists of an actuated plug which is inserted into a socket on the robot’s belly for electrical and mechanical connection. The mechanism is designed for reliable, sealed and spark-free operation. The system has proven to be robust in a laboratory environment and under realistic conditions.