# Reasoning About Liquids via Closed-Loop Simulation

## TL;DR

This paper presents a closed-loop simulation approach that integrates real-time perception to correct liquid state errors, enabling more accurate reasoning about liquids, including occluded scenarios.

## Contribution

It introduces a novel method to close the loop between liquid simulation and perception, reducing divergence and improving reasoning about complex liquid interactions.

## Key findings

- Closed-loop simulation reduces divergence between real and simulated liquids.
- Method enables reasoning about occluded liquids.
- Improves accuracy of liquid state tracking in simulation.

## Abstract

Simulators are powerful tools for reasoning about a robot's interactions with its environment. However, when simulations diverge from reality, that reasoning becomes less useful. In this paper, we show how to close the loop between liquid simulation and real-time perception. We use observations of liquids to correct errors when tracking the liquid's state in a simulator. Our results show that closed-loop simulation is an effective way to prevent large divergence between the simulated and real liquid states. As a direct consequence of this, our method can enable reasoning about liquids that would otherwise be infeasible due to large divergences, such as reasoning about occluded liquid.