Validation of Space Robotics in Underwater Environments via Disturbance Robustness Equivalency

TL;DR

This paper proposes a validation framework for space robotics using underwater environments to simulate microgravity, ensuring mission robustness despite environmental differences, validated through experiments with underwater robots and space simulators.

Contribution

It introduces a method to validate space robotics by matching disturbance robustness levels in underwater environments, bridging the gap between space and underwater testing.

Findings

Underwater validation can effectively approximate space conditions.

The framework successfully compares disturbance robustness between environments.

Experimental results demonstrate the approach's practical viability.

Abstract

We present an experimental validation framework for space robotics that leverages underwater environments to approximate microgravity dynamics. While neutral buoyancy conditions make underwater robotics an excellent platform for space robotics validation, there are still dynamical and environmental differences that need to be overcome. Given a high-level space mission specification, expressed in terms of a Signal Temporal Logic specification, we overcome these differences via the notion of maximal disturbance robustness of the mission. We formulate the motion planning problem such that the original space mission and the validation mission achieve the same disturbance robustness degree. The validation platform then executes its mission plan using a near-identical control strategy to the space mission where the closed-loop controller considers the spacecraft dynamics. Evaluating our validation framework relies on estimating disturbances during execution and comparing them to the disturbance robustness degree, providing practical evidence of operation in the space environment. Our evaluation features a dual-experiment setup: an underwater robot operating under near-neutral buoyancy conditions to validate the planning and control strategy of either an experimental planar spacecraft platform or a CubeSat in a high-fidelity space dynamics simulator.