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Researchers introduce novel approach allowing robots to be trained in simulations of scanned home environments

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Researchers introduce novel approach allowing robots to be trained in simulations of scanned home environments


Precision home robots learn with real-to-sim-to-real
With the help of “digital twins,” RialTo, developed by MIT researchers Marcel Torne Villasevil (left) and Pulkit Agrawal, can guide a robot to practice in a simulated environment much faster than it would if it honed its skills in the real world. Credit: Mike Grimmett/MIT CSAIL

At the top of many automation wish lists is a particularly time-consuming task: chores.

The moonshot of many roboticists is cooking up the proper hardware and software combination so that a machine can learn “generalist” policies (the rules and strategies that guide robot behavior) that work everywhere, under all conditions.

Realistically, though, if you have a home robot, you probably don’t care much about it working for your neighbors. MIT Computer Science and Artificial Intelligence Laboratory (CSAIL) researchers decided, with that in mind, to attempt to find a solution to easily train robust robot policies for very specific environments.

“We aim for robots to perform exceptionally well under disturbances, distractions, varying lighting conditions, and changes in object poses, all within a single environment,” says Marcel Torne Villasevil, MIT CSAIL research assistant in the Improbable AI lab and lead author on a paper about the work, which appears on the preprint server arXiv.

“We propose a method to create digital twins on the fly using the latest advances in computer vision. With just their phones, anyone can capture a digital replica of the real world, and the robots can train in a simulated environment much faster than the real world, thanks to GPU parallelization. Our approach eliminates the need for extensive reward engineering by leveraging a few real-world demonstrations to jump-start the training process.”

Taking your robot home

RialTo, of course, is a little more complicated than just a simple wave of a phone and (boom!) home bot at your service. It begins by using your device to scan the target environment using tools like NeRFStudio, ARCode, or Polycam. Once the scene is reconstructed, users can upload it to RialTo’s interface to make detailed adjustments, add necessary joints to the robots, and more.

The refined scene is exported and brought into the simulator. Here, the aim is to develop a policy based on real-world actions and observations, such as one for grabbing a cup on a counter. These real-world demonstrations are replicated in the simulation, providing some valuable data for reinforcement learning.

“This helps in creating a strong policy that works well in both the simulation and the real world. An enhanced algorithm using reinforcement learning helps guide this process, to ensure the policy is effective when applied outside of the simulator,” says Torne.

Testing showed that RialTo created strong policies for a variety of tasks, whether in controlled lab settings or more unpredictable real-world environments, improving 67% over imitation learning with the same number of demonstrations. The tasks involved opening a toaster, placing a book on a shelf, putting a plate on a rack, placing a mug on a shelf, opening a drawer, and opening a cabinet.

For each task, the researchers tested the system’s performance under three increasing levels of difficulty: randomizing object poses, adding visual distractors, and applying physical disturbances during task executions. When paired with real-world data, the system outperformed traditional imitation-learning methods, especially in situations with lots of visual distractions or physical disruptions.






Precision Home Robotics w/Real-to-Sim-to-Real. Credit: MIT CSAIL

“These experiments show that if we care about being very robust to one particular environment, the best idea is to leverage digital twins instead of trying to obtain robustness with large-scale data collection in diverse environments,” says Pulkit Agrawal, director of Improbable AI Lab, MIT electrical engineering and computer science (EECS) associate professor, MIT CSAIL principal investigator, and senior author on the work.

As far as limitations, RialTo currently takes three days to be fully trained. To speed this up, the team mentions improving the underlying algorithms and using foundation models. Training in simulation also has its limitations, and currently it’s difficult to do effortless sim-to-real transfer and simulate deformable objects or liquids.

The next level

So what’s next for RialTo’s journey? Building on previous efforts, the scientists are working on preserving robustness against various disturbances while improving the model’s adaptability to new environments.

“Our next endeavor is this approach to using pre-trained models, accelerating the learning process, minimizing human input, and achieving broader generalization capabilities,” says Torne.

“We’re incredibly enthusiastic about our ‘on-the-fly’ robot programming concept, where robots can autonomously scan their environment and learn how to solve specific tasks in simulation. While our current method has limitations—such as requiring a few initial demonstrations by a human and significant compute time for training these policies (up to three days)—we see it as a significant step towards achieving ‘on-the-fly’ robot learning and deployment,” says Torne.

“This approach moves us closer to a future where robots won’t need a preexisting policy that covers every scenario. Instead, they can rapidly learn new tasks without extensive real-world interaction. In my view, this advancement could expedite the practical application of robotics far sooner than relying solely on a universal, all-encompassing policy.”

“To deploy robots in the real world, researchers have traditionally relied on methods such as imitation learning from expert data, which can be expensive, or reinforcement learning, which can be unsafe,” says Zoey Chen, a computer science Ph.D. student at the University of Washington who wasn’t involved in the paper.

“RialTo directly addresses both the safety constraints of real-world RL [robot learning], and efficient data constraints for data-driven learning methods, with its novel real-to-sim-to-real pipeline.

“This novel pipeline not only ensures safe and robust training in simulation before real-world deployment, but also significantly improves the efficiency of data collection. RialTo has the potential to significantly scale up robot learning and allows robots to adapt to complex real-world scenarios much more effectively.”

“Simulation has shown impressive capabilities on real robots by providing inexpensive, possibly infinite data for policy learning,” adds Marius Memmel, a computer science Ph.D. student at the University of Washington who wasn’t involved in the work.

“However, these methods are limited to a few specific scenarios, and constructing the corresponding simulations is expensive and laborious. RialTo provides an easy-to-use tool to reconstruct real-world environments in minutes instead of hours.

“Furthermore, it makes extensive use of collected demonstrations during policy learning, minimizing the burden on the operator and reducing the sim2real gap. RialTo demonstrates robustness to object poses and disturbances, showing incredible real-world performance without requiring extensive simulator construction and data collection.”

More information:
Marcel Torne et al, Reconciling Reality through Simulation: A Real-to-Sim-to-Real Approach for Robust Manipulation, arXiv (2024). DOI: 10.48550/arxiv.2403.03949

Journal information:
arXiv


This story is republished courtesy of MIT News (web.mit.edu/newsoffice/), a popular site that covers news about MIT research, innovation and teaching.

Citation:
Researchers introduce novel approach allowing robots to be trained in simulations of scanned home environments (2024, August 1)
retrieved 1 August 2024
from https://techxplore.com/news/2024-08-approach-robots-simulations-scanned-home.html

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New perspectives for using corals in climate research

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New perspectives for using corals in climate research


New perspectives for using corals in climate research
Göttingen University researchers analysed oxygen isotopes from corals, like this Acropora coral, to expand the uses of the “triple oxygen isotope” method and help measure temperatures from the past more accurately. Credit: Dr. David Bajnai

Ancient ocean temperatures are most commonly reconstructed by analyzing the ratio of different oxygen atoms in the calcium carbonate remains of fossils. However, this presents many challenges, including a combination of biological processes known as “vital effects” which are very noticeable in corals and can affect the data.

A research team led by the University of Göttingen now shows how the abundance of a third, very rare oxygen isotope can uncover whether the isotopic composition was solely influenced by temperature or if biological effects also played a role. The results were published in Geochemical Perspective Letters.

The hard structure of coral, known as the “coral skeleton,” is composed of calcium carbonate, the same material that makes up limestones. Corals, like all marine organisms, selectively incorporate different forms of oxygen. These different forms are called isotopes, meaning some oxygen atoms are lighter and some are heavier.

At lower water temperatures, a higher abundance of the heavy oxygen isotope is incorporated into the carbonate structures. By analyzing the ratios of the heavy oxygen-18 isotope to the light oxygen-16 isotope in carbonates, scientists can calculate the ambient seawater temperatures of Earth’s distant past.

However, some carbonates, such as coral skeletons, return false temperatures because their oxygen isotope composition is also affected by the biological processes known as vital effects.

The researchers have now discovered that a third, very rare isotope (oxygen-17) can be used to correct for these biological effects. As a result, researchers can now determine past ocean temperatures with greater accuracy, in addition to gaining more insights into the biomineralization processes of different coral species.

Measurements of this rare oxygen-17 isotope, known in the field as the triple oxygen isotope method, in carbonates are normally very complicated. In fact, the stable isotope laboratory at the Göttingen University is among only a few in the world that can perform such analyses. The lab used cutting-edge instrumentation known as tunable diode laser absorption spectroscopy.

“We used corals for our study as we know quite a lot about the processes by which they grow their skeletons,” said study leader, Dr. David Bajnai at Göttingen University’s Geoscience Center.

“We are excited to apply this concept to other organisms commonly used in the study of Earth’s past climate. We hope that triple oxygen isotope analyses will open up previously unusable datasets for paleoclimate research, enabling more accurate climate reconstructions, going further back in time.”

Professor Daniel Herwartz from the Ruhr University Bochum added, “We were also able to show that triple oxygen isotope analyses can inform us about the various processes we collectively call ‘vital effects.’

“For corals, we can now confirm that the main process involved is related to a chemical process called CO2 absorption, which we have independently studied in experiments. Such advanced techniques help to gain new insights into how organisms build their harder structures.”

More information:
D. Bajnai et al, Correcting for vital effects in coral carbonate using triple oxygen isotopes, Geochemical Perspectives Letters (2024). DOI: 10.7185/geochemlet.2430

Provided by
Georg-August-Universität Göttingen

Citation:
New perspectives for using corals in climate research (2024, August 1)
retrieved 1 August 2024
from https://phys.org/news/2024-08-perspectives-corals-climate.html

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Scientists using new sound tech to save animals from extinction

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Scientists using new sound tech to save animals from extinction


Scientists using new sound tech to save animals from extinction
An illustration of the visualization bias that can occur due to the trade-off between temporal and spectral resolution. Credit: Ecology and Evolution (2024). DOI: 10.1002/ece3.11636

Research, conducted by The University of Warwick and the University of New South Wales in Australia, analyzes animal sounds from endangered species including types of elephants, whales and birds.

It uses a new method adapted from tech used to analyze brain waves in neuroscience. The study is published in the journal Ecology and Evolution.

Analysis of animal sounds can be used to estimate their population size, to identify what animals live in a particular area, to understand their migration patterns, and to understand any negative impacts they may experience due to the increasing levels of noise created by human activity that are occurring in most of their habitats. Such insights are vital in developing environmental management and conservation strategies.

The new method was shown to be more accurate than the conventional methods for analysis of animal sounds. While testing this new method, called the Superlet transform, the study also revealed some previously unreported or disputed details in animal sounds:

  • The Asian elephant call isn’t just made up of continuous tones, but also contains sounds that are “pulsed,” or comprised of regularly timed bursts of sound energy.
  • Pulsing was also shown in the southern cassowary (a large bird similar to an emu) and American crocodile calls.
  • New evidence was uncovered that helps to solve a debate around the characteristics of the Chagos pygmy blue whale’s song.

These are not conclusive findings, as each one is based on just a single recording. To confirm them, more sounds will need to be analyzed. They illustrate, however, the power of this new method to clarify details that previously might have been ambiguous.

Lead Researcher Ben Jancovich, a Ph.D. candidate from The University of New South Wales, and visiting Ph.D. student at The University of Warwick’s Mathematics Institute, said, “Our new study highlights that sometimes, the accepted tools that we’ve become comfortable with, may not actually be the best tools for the job.”

“This is especially true in cross-disciplinary fields like bioacoustics, where the methods are highly technical, and require expertise in multiple fields.”

“The new method we demonstrated offers increased accuracy and requires less expertise to use, so it should prove to be a hugely valuable tool for animal sound researchers that don’t have an engineering background.”

Current methods (including the “Short-Time Fourier Transform,” STFT) have difficulties in accurately revealing both the rhythms and pitch of sounds at the same time.

These limitations are more pronounced at lower frequencies, affecting the analysis of sounds like those made by blue whales—gentle giants of the sea, sadly listed as an endangered species.

The new technology will be available for people to use for free, via a simple-to-use app, making it easy for researchers from different fields to use, without needing extensive knowledge of audio signal analysis.

More information:
Benjamin A. Jancovich et al, BASSA: New software tool reveals hidden details in visualisation of low‐frequency animal sounds, Ecology and Evolution (2024). DOI: 10.1002/ece3.11636

Citation:
Scientists using new sound tech to save animals from extinction (2024, August 1)
retrieved 1 August 2024
from https://phys.org/news/2024-08-scientists-tech-animals-extinction.html

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part may be reproduced without the written permission. The content is provided for information purposes only.





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Beetle-inspired robots show improved flight capabilities

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Beetle-inspired robots show improved flight capabilities


Biomechanics: Beetle wing mechanisms inspire robot design
The flapping microrobot takes flight with passive deploying-retracting wings. Credit: Hoang-Vu Phan

An analysis of how rhinoceros beetles deploy and retract their hindwings shows that the process is passive, requiring no muscular activity. The findings, reported in Nature, could help improve the design of flying micromachines.

Among all flying insects, beetles demonstrate the most complex wing mechanisms, involving two sets of wings: a pair of hardened forewings called elytra and a set of delicate membranous hindwings. Although extensive research exists on the origami-like folds of their wings, little is known about how they deploy and retract their hindwings.

Previous research theorizes that thoracic muscles drive a beetle’s hindwing base movement, but experimental evidence to support this theory is lacking.

Hoang-Vu Phan and colleagues combine the use of high-speed cameras and a dynamically similar flying robot to address this research gap. The authors observe that rhinoceros beetles use passive mechanisms, including their elytra, when deploying and retracting their wings.






Flapping robot passively deploys and retracts its wings. Credit: Hoang Vu Phan

Deployment is a two-phase process in which elevation of the elytra partially releases their hindwings in a spring-like fashion, then a flapping motion brings the hindwings into a raised flight position. They also find the beetles use their elytra to lower their hindwings into a resting position passively.

Inspired by their observations, the authors make microrobots that mimic beetle wings’ passive deployment and retraction. They find the bots successfully take off and maintain flight.






Beetle wing deployment. Credit: Hoang Vu Phan

Their findings suggest that transferring the beetle’s passive hindwing processes to a flapping robot design could help to improve the capabilities of small robots that need to operate in limited or cluttered spaces.

More information:
Hoang-Vu Phan et al, Passive wing deployment and retraction in beetles and flapping microrobots, Nature (2024). DOI: 10.1038/s41586-024-07755-9

Citation:
Beetle-inspired robots show improved flight capabilities (2024, August 1)
retrieved 1 August 2024
from https://techxplore.com/news/2024-08-beetle-robots-flight-capabilities.html

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Study reveals soliton solutions in Maxwell-Bloch systems

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Study reveals soliton solutions in Maxwell-Bloch systems


quantum
Credit: Pixabay/CC0 Public Domain

Dr. Asela Abeya, of SUNY Poly faculty in the Department of Mathematics and Physics, has collaborated with peers at the University at Buffalo and Rensselaer Polytechnic Institute on a research paper titled “On Maxwell-Bloch systems with inhomogeneous broadening and one-sided nonzero background,” which has been published in Communications in Mathematical Physics.

Dr. Abeya explains that Maxwell-Bloch equations are foundational in optical physics, describing the interaction between electromagnetic fields and atomic populations.

Essential for modeling laser dynamics, these equations help explain critical phenomena such as super radiance, coherent population trapping, and optical bistability. They also provide insights into nonlinear optical effects like harmonic generation and soliton propagation.

By bridging classical and quantum realms, the Maxwell-Bloch equations are crucial for advancements in laser technology, quantum computing, and secure communications, as well as in exploring the profound dynamics of light-matter interactions.

The Maxwell-Bloch equations for two- and certain three-level media are completely integrable in the sense of possessing a Lax Pair (zero-curvature) representation, notes Dr. Abeya. Integrability makes it possible to more accurately linearize these equations via the Inverse Scattering Transform (IST) and enables the use of various transformation methods to “dress” simple exact solutions into more complicated and physically relevant ones, Dr. Abeya explains.

In this work, Dr. Abeya uses IST to solve the Maxwell-Bloch system corresponding to light pulses riding on continuous waves that are in the process of either turning on or off.

In this study, Dr. Abeya and peers show that the soliton solutions are always accompanied by radiation (existence of truncated solitons). Furthermore, the authors discuss the asymptotic state of the medium and certain features of the optical pulse inside the medium, and the emergence of a transition region upon propagation in the medium.

Dr. Abeya presented an invited talk on this significant result at the Society for Industrial and Applied Mathematics (SIAM) conference on Nonlinear Waves and Coherent Structures in Baltimore, MD, in June 2024.

More information:
Asela Abeya et al, On Maxwell-Bloch Systems with Inhomogeneous Broadening and One-sided Nonzero Background, Communications in Mathematical Physics (2024). DOI: 10.1007/s00220-024-05054-y

Citation:
Study reveals soliton solutions in Maxwell-Bloch systems (2024, August 1)
retrieved 1 August 2024
from https://phys.org/news/2024-08-reveals-soliton-solutions-maxwell-bloch.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





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