Dropping Counter: A Detection Algorithm for Identifying Odour-Evoked Responses from Noisy Electroantennograms Measured by a Flying Robot

Abstract

The electroantennogram (EAG) is a technique used for measuring electrical signals from the antenna of an insect. Its rapid response time, quick recovery speed, and high sensitivity make it suitable for odour-tracking tasks employing mobile robots. However, its application to flying robots has not been extensively studied owing to the electrical and mechanical noises generated. In this study, we investigated the characteristics of the EAG mounted on a tethered flying quadcopter and developed a special counter-based algorithm for detecting the odour-generated responses. As the EAG response is negative, the algorithm creates a window and compares the values inside it. Once a value is smaller than the first one, the counter will increase by one and finally turns the whole signal into a clearer odour stimulated result. By experimental evaluation, the new algorithm gives a higher cross-correlation coefficient when compared with the fixed-threshold method. The result shows that the accuracy of this novel algorithm for recognising odour-evoked EAG signals from noise exceeds that of the traditional method; furthermore, the use of insect antennae as odour sensors for flying robots is demonstrated to be feasible.

Moth-inspired odor source localization using robotic platforms: A comprehensive review

“…There are other varied experiments like training moths to detect explosives (Horine et al, 2004), behavioral model to control mobile robot (Kanzaki, 2007;Kanzaki et al, 2004Kanzaki et al, , 2005, new proposed TVMI algorithm (Shigaki et al, 2018). The recent trend suggests the use of tethered aerial vehicle or UAVs preferably small which uses excised moth antennae or EAG device as a biosensor to localize an odor source (Anderson et al, 2019(Anderson et al, , 2020Lan et al, 2019;Terutsuki et al, 2021aTerutsuki et al, , 2021b. However, these experiments were conducted in lab environments except a few; hence, applications in real-life scenarios are still to be explored.…”

“…The odor-evoked EAG signal was enhanced in the midst of noise using a developed dropping counter algorithm. It showed an improved correlation coefficient and accuracy as compared to the traditional fixed threshold method (Lan et al, 2019). An autonomous palm-sized aerial vehicle integrated with excised antennae of living M. sexta as a pheromone sensor was reported.…”

Dynamic Model Identification for Insect Electroantennogram with Printed Electrode

“…In our previous research, (16) the basic electrical characteristics of this ink and the film composition were comprehensively investigated, and it was found that the longer the side length and the narrower the width, the larger the resistance. This electrical characteristic is the same as that of a general lead wire, and it has been reported that EAGs can be measured even with a general IC pin socket; (17,18) therefore, we assumed that EAGs can be adequately measured with this printed electrode.…”

A bio-hybrid odor-guided autonomous palm-sized air vehicle

“…Notable examples of biohybrid robotic systems using living sensors on ground robots include a mobile robot in a wind tunnel using a moth EAG [18], an odor tracking mobile robot steered based on input from a moths' ambulation motions on a sensitive trackball [19], and a ground robot capable of avoiding collisions by using a fly's visual system to perform optic flow estimates [20]. There have also been some systems integrating biological and bioinspired components on flying systems such as a drone being steered by an off-board moth on a trackball [21] and the development of an algorithm to improve an EAG signal onboard a tethered 0.5 m drone [22].…”