Evidence map›Paper›PMID 34880221›Full record

ArticleNature communications2021

Learning efficient navigation in vortical flow fields.

Peter Gunnarson, Ioannis Mandralis, Guido Novati, Petros Koumoutsakos, John O Dabiri

Abstract read
In one paragraph

Article in Nature communications, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers.

0numbers the graph read from it
0cells of the map it votes in
12citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

12 citing papers in PubMed.

  1. Article
  2. Article
  3. Learning to Navigate in Chemical Fields Without A Map at Low Reynolds Numbers.Advanced science (Weinheim, Baden-Wurttemberg, Germany) · 2025
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  12. Finite-horizon, energy-efficient trajectories in unsteady flows.Proceedings. Mathematical, physical, and engineering sciences · 2022
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Peter GunnarsonGraduate Aerospace Laboratories, California Institute of Technology, 1200 E California Blvd, Pasadena, CA, 91125, USA.
Ioannis MandralisGraduate Aerospace Laboratories, California Institute of Technology, 1200 E California Blvd, Pasadena, CA, 91125, USA.
Guido NovatiComputational Science and Engineering Laboratory, ETH Zurich, 8093, Zurich, Switzerland.ORCID 0000-0003-0681-4892
Petros KoumoutsakosComputational Science and Engineering Laboratory, ETH Zurich, 8093, Zurich, Switzerland.ORCID 0000-0001-8337-2122
John O DabiriGraduate Aerospace Laboratories, California Institute of Technology, 1200 E California Blvd, Pasadena, CA, 91125, USA. jodabiri@caltech.edu.ORCID 0000-0002-6722-9008

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Efficient point-to-point navigation in the presence of a background flow field is important for robotic applications such as ocean surveying. In such applications, robots may only have knowledge of their immediate surroundings or be faced with time-varying currents, which limits the use of optimal control techniques. Here, we apply a recently introduced Reinforcement Learning algorithm to discover time-efficient navigation policies to steer a fixed-speed swimmer through unsteady two-dimensional flow fields. The algorithm entails inputting environmental cues into a deep neural network that determines the swimmer's actions, and deploying Remember and Forget Experience Replay. We find that the resulting swimmers successfully exploit the background flow to reach the target, but that this success depends on the sensed environmental cue. Surprisingly, a velocity sensing approach significantly outperformed a bio-mimetic vorticity sensing approach, and achieved a near 100% success rate in reaching the target locations while approaching the time-efficiency of optimal navigation trajectories.

Identifiers

PMID34880221
PMCPMC8654940

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.