A thermodynamics-informed active learning approach to perception and reasoning about fluids

Learning and reasoning about physical phenomena is still a challenge in robotics development, and computational sciences play a capital role in the search for accurate methods able to provide explanations for past events and rigorous forecasts of future situations. We propose a thermodynamics-informed active learning strategy for fluid perception and reasoning from observations. As a model problem, we take the sloshing phenomena of different fluids contained in a glass. Starting from full-field and high-resolution synthetic data for a particular fluid, we develop a method for the tracking (perception) and simulation (reasoning) of any previously unseen liquid whose free surface is observed with a commodity camera. This approach demonstrates the importance of physics and knowledge not only in data-driven (gray-box) modeling but also in real-physics adaptation in low-data regimes and partial observations of the dynamics. The presented method is extensible to other domains such as the development of cognitive digital twins able to learn from observation of phenomena for which they have not been trained explicitly

Reasoning About Liquids via Closed-Loop Simulation

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.Comment: Robotics: Science & Systems (RSS), July 12-16, 2017. Cambridge, MA, US

A thermodynamics-informed active learning approach to perception and reasoning about fluids

Learning and reasoning about physical phenomena is still a challenge in robotics development, and computational sciences play a capital role in the search for accurate methods able to provide explanations for past events and rigorous forecasts of future situations. We propose a thermodynamics-informed active learning strategy for fluid perception and reasoning from observations. As a model problem, we take the sloshing phenomena of different fluids contained in a glass. Starting from full-field and high-resolution synthetic data for a particular fluid, we develop a method for the tracking (perception) and simulation (reasoning) of any previously unseen liquid whose free surface is observed with a commodity camera. This approach demonstrates the importance of physics and knowledge not only in data-driven (gray-box) modeling but also in real-physics adaptation in low-data regimes and partial observations of the dynamics. The presented method is extensible to other domains such as the development of cognitive digital twins able to learn from observation of phenomena for which they have not been trained explicitly

PourIt!: Weakly-supervised Liquid Perception from a Single Image for Visual Closed-Loop Robotic Pouring

Liquid perception is critical for robotic pouring tasks. It usually requires the robust visual detection of flowing liquid. However, while recent works have shown promising results in liquid perception, they typically require labeled data for model training, a process that is both time-consuming and reliant on human labor. To this end, this paper proposes a simple yet effective framework PourIt!, to serve as a tool for robotic pouring tasks. We design a simple data collection pipeline that only needs image-level labels to reduce the reliance on tedious pixel-wise annotations. Then, a binary classification model is trained to generate Class Activation Map (CAM) that focuses on the visual difference between these two kinds of collected data, i.e., the existence of liquid drop or not. We also devise a feature contrast strategy to improve the quality of the CAM, thus entirely and tightly covering the actual liquid regions. Then, the container pose is further utilized to facilitate the 3D point cloud recovery of the detected liquid region. Finally, the liquid-to-container distance is calculated for visual closed-loop control of the physical robot. To validate the effectiveness of our proposed method, we also contribute a novel dataset for our task and name it PourIt! dataset. Extensive results on this dataset and physical Franka robot have shown the utility and effectiveness of our method in the robotic pouring tasks. Our dataset, code and pre-trained models will be available on the project page.Comment: ICCV202

Building Machines That Learn and Think Like People

Recent progress in artificial intelligence (AI) has renewed interest in building systems that learn and think like people. Many advances have come from using deep neural networks trained end-to-end in tasks such as object recognition, video games, and board games, achieving performance that equals or even beats humans in some respects. Despite their biological inspiration and performance achievements, these systems differ from human intelligence in crucial ways. We review progress in cognitive science suggesting that truly human-like learning and thinking machines will have to reach beyond current engineering trends in both what they learn, and how they learn it. Specifically, we argue that these machines should (a) build causal models of the world that support explanation and understanding, rather than merely solving pattern recognition problems; (b) ground learning in intuitive theories of physics and psychology, to support and enrich the knowledge that is learned; and (c) harness compositionality and learning-to-learn to rapidly acquire and generalize knowledge to new tasks and situations. We suggest concrete challenges and promising routes towards these goals that can combine the strengths of recent neural network advances with more structured cognitive models.Comment: In press at Behavioral and Brain Sciences. Open call for commentary proposals (until Nov. 22, 2016). https://www.cambridge.org/core/journals/behavioral-and-brain-sciences/information/calls-for-commentary/open-calls-for-commentar

Learned simulation as the engine of physical scene understanding

La cognición humana evoca las habilidades del razonamiento, la comunicación y la interacción. Esto incluye la interpretación de la física del mundo real para comprender las leyes que subyacen en ella. Algunas teorías postulan la semejanza entre esta capacidad de razonamiento con simulaciones para interpretar la física de la escena, que abarca la percepción para la comprensión del estado físico actual, y el razonamiento acerca de la evolución temporal de un sistema dado. En este contexto se propone el desarrollo de un sistema para realizar simulación aprendida. Establecido un objetivo, el algoritmo se entrena para aprender una aproximación de la dinámica real, para construir así un gemelo digital del entorno. Entonces, el sistema de simulación emulará la física subyacente con información obtenida mediante observaciones de la escena. Para ello, se empleará una cámara estéreo para adquirir datos a partir de secuencias de video. El trabajo se centra los fenómenos oscilatorios de fluidos. Los fluidos están presentes en muchas de nuestras acciones diarias y constituyen un reto físico para el sistema propuesto. Son deformables, no lineales, y presentan un carácter disipativo dominante, lo que los convierte en un sistema complejo para ser aprendido. Además, sólo se tiene acceso a mediciones parciales de su estado ya que la cámara sólo proporciona información acerca de la superficie libre. El resultado es un sistema capaz de percibir y razonar sobre la dinámica del fluido. El gemelo digital cognitivo así construido proporciona una interpretación del estado del mismo para integrar su evolución en tiempo real, aprendiendo con información observada del gemelo físico. El sistema, entrenado originalmente para un líquido concreto, se adaptará a cualquier otro a través del aprendizaje por refuerzo produciendo así resultados precisos para líquidos desconocidos. Finalmente, se emplea la realidad aumentada (RA) para ofrecer una representación visual de los resultados, así como información adicional sobre el estado del líquido que no es accesible al ojo humano. Este objetivo se alcanza mediante el uso de técnicas de aprendizaje de variedades, y aprendizaje automático, como las redes neuronales, enriquecido con información física. Empleamos sesgos inductivos basados en el conocimiento de la termodinámica para desarrollar un sistema inteligente que cumpla con estos principios para dar soluciones con sentido sobre la dinámica. El problema abordado en esta tesis constituye una dificultad de primer orden en el desarrollo de sistemas robóticos destinados a la manipulación de fluidos. En acciones como el vertido o el movimiento, la oscilación de los líquidos juega un papel importante en el desarrollo de sistemas de asistencia a personas con movilidad reducida o aplicaciones industriales. Cognition evokes human abilities for reasoning, communication, and interaction. This includes the interpretation of real-world physics so as to understand its underlying laws. Theories postulate the similarity of human reasoning about these phenomena with simulations for physical scene understanding, which gathers perception for comprehension of the current dynamical state, and reasoning for time evolution prediction of a given system. In this context, we propose the development of a system for learned simulation. Given a design objective, an algorithm is trained to learn an approximation to the real dynamics to build a digital twin of the environment. Then, the underlying physics will be emulated with information coming from observations of the scene. For this purpose, we use a commodity camera to acquire data exclusively from video recordings. We focus on the sloshing problem as a benchmark. Fluids are widely present in several daily actions and portray a physically rich challenge for the proposed systems. They are highly deformable, nonlinear, and present a dominant dissipative behavior, making them a complex entity to be emulated. In addition, we only have access to partial measurements of their dynamical state, since a commodity camera only provides information about the free surface. The result is a system capable of perceiving and reasoning about the dynamics of the fluid. This cognitive digital twin provides an interpretation of the state of the fluid to integrate its dynamical evolution in real-time, updated with information observed from the real twin. The system, trained originally for one liquid, will be able to adapt itself to any other fluid through reinforcement learning and produce accurate results for previously unseen liquids. Augmented reality is used in the design of this application to offer a visual interpretation of the solutions to the user, and include information about the dynamics that is not accessible to the human eye. This objective is to be achieved through the use of manifold learning and machine learning techniques, such as neural networks, enriched with physics information. We use inductive biases based on the knowledge of thermodynamics to develop machine intelligence systems that fulfill these principles to provide meaningful solutions to the dynamics. This problem is considered one of the main targets in fluid manipulation for the development of robotic systems. Pursuing actions such as pouring or moving, sloshing dynamics play a capital role for the correct performance of aiding systems for the elderly or industrial applications that involve liquids. <br /