Toward Space Exploration on Legs: ISS-to-Earth Teleoperation Experiments with a Quadruped Robot

Abstract

In uneven terrains of lunar and planetary surfaces, a teleoperated legged robot enables the exploration of areas that may be inaccessible to wheeled rovers. The on-going DLR-ESA Surface Avatar technology demonstration mission studies and validates technologies needed to realize the command of a heterogeneous robotic team with various command modalities. In the latest experiments, the crew on-board the International Space Station (ISS) is tasked to command a team of different robots with Scalable Autonomy, meaning they may choose to command the robots through direct control, shared control, or delegate tasks with Supervised Autonomy. One of the robots in the robotic team is DLR’s small quadruped, Bert. Equipped with a robotic arm on its back, also serving as camera mount, Bert can observe its surroundings and pick up small objects. Due to its serial-elastic joints, the hardware is robust to impacts, which is critical for space deployment. Applying adaptive learning strategies, Bert’s gaits can be (re)trained directly on hardware to adapt to different environment and gravity conditions. The quadruped as well as its back-mounted arm can be commanded through direct control by the astronauts via a joystick on-board the ISS. Additionally, simple preset task-level commands complement the user interface to ease the astronauts’ workload. This paper presents the ISS experiments of the first legged robot telecommanded from space. Examining different aspects of Bert’s telerobotic performance as well as the ISS crew feedback, we discuss the feasibility of teleoperated walking robots in space exploration.