FLIP: Flowability-Informed Powder Weighing

TL;DR

FLIP is a framework that improves robotic powder weighing by using flowability data to create accurate simulations and a curriculum learning strategy, leading to more precise handling of diverse powders.

Contribution

The paper introduces FLIP, a novel approach that integrates flowability measurements into simulation and curriculum learning to enhance robotic powder handling.

Findings

Achieves low dispensing error of 2.12 mg with FLIP.

Outperforms domain randomisation in accuracy.

Demonstrates improved generalisation to unseen powders.

Abstract

Autonomous manipulation of powders remains a significant challenge for robotic automation in scientific laboratories. The inherent variability and complex physical interactions of powders in flow, coupled with variability in laboratory conditions necessitates adaptive automation. This work introduces FLIP, a flowability-informed powder weighing framework designed to enhance robotic policy learning for granular material handling. Our key contribution lies in using material flowability, quantified by the angle of repose, to optimise physics-based simulations through Bayesian inference. This yields material-specific simulation environments capable of generating accurate training data, which reflects diverse powder behaviours, for training "robot chemists". Building on this, FLIP integrates quantified flowability into a curriculum learning strategy, fostering efficient acquisition of robust robotic policies by gradually introducing more challenging, less flowable powders. We validate the efficacy of our method on a robotic powder weighing task under real-world laboratory conditions. Experimental results show that FLIP with a curriculum strategy achieves a low dispensing error of 2.12 +/- 1.53 mg, outperforming methods that do not leverage flowability data, such as domain randomisation (6.11 +/- 3.92 mg). These results demonstrate FLIP's improved ability to generalise to previously unseen, more cohesive powders and to new target masses.