Place recognition using batlike sonar

Vanderelst, Dieter; Steckel, Jan; Boen, Andre; Peremans, Herbert; Holderied, Marc W.

doi:10.7554/elife.14188

Cited by 30 publications

(30 citation statements)

References 74 publications

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“…Several engineering initiatives have made use of sensory-guided navigation to control autonomous vehicles (Baker et al, 2014;Conte and Doherty, 2008;Smith et al, 2013;Steckel and Peremans, 2017;Strydom et al, 2014) or create devices to help visually impaired individuals move safely within their environment (Filipe et al, 2012;Katzschmann et al, 2018;Lee and Medioni, 2011). While some of these systems use patterns of light, such as optic flow, to process information from the environment (Conte and Doherty, 2008;Strydom et al, 2014), recent work in sonar-based navigation has incorporated acoustic flow cues to automatically steer unmanned vehicles through complex corridors (Baker et al, 2014;Peremans and Steckel, 2014;Smith et al, 2014;Steckel and Peremans, 2017;Vanderelst et al, 2016). Most of the acoustic-based navigation devices have been tested in environments that contain large objects or flat surfaces, and it would be interesting to test the behavior of these systems in environments that create echo flow patterns similar to those presented here.…”

Section: Discussionmentioning

confidence: 99%

Echo interval and not echo intensity drives bat flight behavior in structured corridors

Warnecke

Macías

Falk

et al. 2018

Journal of Experimental Biology

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To navigate in the natural environment, animals must adapt their locomotion in response to environmental stimuli. The echolocating bat relies on auditory processing of echo returns to represent its surroundings. Recent studies have shown that echo flow patterns influence bat navigation, but the acoustic basis for flight path selection remains unknown. To investigate this problem, we released bats in a flight corridor with walls constructed of adjacent individual wooden poles, which returned cascades of echoes to the flying bat. We manipulated the spacing and echo strength of the poles comprising each corridor side, and predicted that bats would adapt their flight paths to deviate toward the corridor side returning weaker echo cascades. Our results show that the bat's trajectory through the corridor was not affected by the intensity of echo cascades. Instead, bats deviated toward the corridor wall with more sparsely spaced, highly reflective poles, suggesting that pole spacing, rather than echo intensity, influenced bat flight path selection. This result motivated investigation of the neural processing of echo cascades. We measured local evoked auditory responses in the bat inferior colliculus to echo playback recordings from corridor walls constructed of sparsely and densely spaced poles. We predicted that evoked neural responses would be discretely modulated by temporally distinct echoes recorded from the sparsely spaced pole corridor wall, but not by echoes from the more densely spaced corridor wall. The data confirm this prediction and suggest that the bat's temporal resolution of echo cascades may drive its flight behavior in the corridor.

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Section: Discussionmentioning

confidence: 99%

Echo interval and not echo intensity drives bat flight behavior in structured corridors

Warnecke

Macías

Falk

et al. 2018

Journal of Experimental Biology

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“…Petrites et al [25], Barchi et al [29] and Knowles et al [15] used 4 cm wide chains as obstacles (See [2,34] for more early references). However, the tubes being simple human- made obstacles do not return the multiple echoes that are characteristic for vegetation (compare, [14,35,36]). Therefore, we wrapped the cardboard tubes in artificial ivy vines (Fig 1).…”

Section: Rectangular Arenamentioning

confidence: 99%

“…While bats can locate the origin of single reflectors with high precision, inferring the azimuth and elevation of a reflector is not a trivial computation [46]. Moreover, when the bat receives a cascade of overlapping echoes with limited signal-to-noise ratio, localization might be not feasible at all [2,17,36,46]. Therefore, bats might be assumed to often operate under conditions where they have limited access to angular information.…”

Section: Avoidance Of Non-localized Obstaclesmentioning

confidence: 99%

“…Therefore, bats might be assumed to often operate under conditions where they have limited access to angular information. For example, vegetation returns a statistical ensemble of echoes rather than individual and separated echoes [35,36,47]. Both recent neurophysiological [14] and behavioral [15] evidence from bats flying through corridors lined with obstacles support the view that, when multiple echoes return within a window of about 2 ms, bats are not capable of perceiving the echoes as separate reflectors.…”

Section: Avoidance Of Non-localized Obstaclesmentioning

confidence: 99%

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Avoidance of non-localizable obstacles in echolocating bats: A robotic model

et al. 2019

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Most objects and vegetation making up the habitats of echolocating bats return a multitude of overlapping echoes. Recent evidence suggests that the limited temporal and spatial resolution of bio-sonar prevents bats from separately perceiving the objects giving rise to these overlapping echoes. Therefore, bats often operate under conditions where their ability to localize obstacles is severely limited. Nevertheless, bats excel at avoiding complex obstacles. In this paper, we present a robotic model of bat obstacle avoidance using interaural level differences and distance to the nearest obstacle as the minimal set of cues. In contrast to previous robotic models of bats, the current robot does not attempt to localize obstacles. We evaluate two obstacle avoidance strategies. First, the Fixed Head Strategy keeps the acoustic gaze direction aligned with the direction of flight. Second, the Delayed Linear Adaptive Law (DLAL) Strategy uses acoustic gaze scanning, as observed in hunting bats. Acoustic gaze scanning has been suggested to aid the bat in hunting for prey. Here, we evaluate its adaptive value for obstacle avoidance when obstacles can not be localized. The robot's obstacle avoidance performance is assessed in two environments mimicking (highly cluttered) experimental setups commonly used in behavioral experiments: a rectangular arena containing multiple complex cylindrical reflecting surfaces and a corridor lined with complex reflecting surfaces. The results indicate that distance to the nearest object and interaural level differences allows steering the robot clear of obstacles in environments that return non-localizable echoes. Furthermore, we found that using acoustic gaze scanning reduced performance, suggesting that gaze scanning might not be beneficial under conditions where the animal has limited access to angular information, which is in line with behavioral evidence.

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“…Bats use echolocation to sense the environment actively. Over a period of 50 million years, they have evolved an echolocation system that allows them to hunt for insects, forage for fruit or flower nectar and navigate in complex environments [1][2][3][4][5]. Similarly, modern radar (and sonar) systems rely on active sensing to support a variety of tasks that include detection and classification of targets, accurate localization and tracking, autonomous navigation and collision avoidance [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Bio‐inspired processing of radar target echoes

Georgiev

Balleri

Stove³

et al. 2018

IET Radar, Sonar & Navigation

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Echolocating bats have evolved the ability to detect, resolve and discriminate targets in highly challenging environments using biological sonar. The way bats process signals in the receiving auditory system is not the same as that of radar and sonar and hence investigating differences and similarities might provide useful lessons to improve synthetic sensors. The Spectrogram Correlation And Transformation receiver (SCAT) is an existing model of the bat auditory system that takes into account the physiology and the neural organisation of bats that emit broadband signals. In this paper, we present a baseband receiver equivalent to the SCAT that allows an analysis of target echoes at baseband. The Baseband SCAT (BSCT) is used to investigate the output of the bat-auditory model for two closely spaced scatterers and to carry out an analysis of range resolution performance and a comparison with the conventional matched filter. Results firstly show that the BSCT provides improved resolution performance. It is then demonstrated that the output of the BSCT can be obtained with an equivalent matched-filter based receiver. The results are verified with a set of laboratory experiments at radio frequencies in high Signal to Noise Ratio (SNR).

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Place recognition using batlike sonar

Cited by 30 publications

References 74 publications

Echo interval and not echo intensity drives bat flight behavior in structured corridors

Echo interval and not echo intensity drives bat flight behavior in structured corridors

Avoidance of non-localizable obstacles in echolocating bats: A robotic model

Bio‐inspired processing of radar target echoes

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