Chemical plume tracing

Abstract

Most of the reported three-dimensional chemical plume tracing methods use stereo sensing method to determine the next tracing step direction. For example, multiple sensors are used for detection in the left, right, up and down directions. Left and right detections are feasible for stereo sniffing; unfortunately, the same approach is infeasible for the up/down sensing of the quadrotor platforms because the propellers of the quadrotor continuously draw the air from the top and bring it down, which affects the sensing of the upper and lower sensors, and fails to determine the subsequent tracing step of up/down direction. Therefore, up/down sensing in the surging stage of chemical plume tracing is ineffective for quadrotor platforms (chemical plume tracing has two stages: surging and casting). To solve the problem, we propose an alternative that is not in the surging but in the casting stage of chemical plume tracing, by designing a new three-dimensional chemical plume tracing technique with variations of altitude (z-axis) control during the casting stage, which has never been considered in the previous works. Besides, we use a computational fluid dynamics software to study the airflow pattern of quadrotor platform. Subsequently, a fuzzy-based stereo-sniffing algorithm is developed by considering the quadrotor propeller's air intake stream angle associated with the environmental wind direction angle, so as to improve the accuracy of stereo sensing. The results of the proposed solutions are verified and validated via both experimental and simulation approaches.

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

“…The altitude of 1000 mm is the normal one when the drone is autonomously hovering. To verify the result of the free hovering flight [29], we measured the wind speed over a propeller and under it during a tethered flight using a hot-wire anemometer (DT-8880, CEM, Shenzhen, China). The result just matched the theory in that the later reading value was around 7–10 m/s, which was almost double the former (Figure 3), as the sensor can catch the chemical plume more than twice and enhance the sensing opportunities.…”

Plume Tracking Strategy in Turbulent Environment using Odor Sensor with Time Constant

“…where r(k) and r(k + 1) are the observed sensor responses at time k and k + 1, respectively. The sensing method by Eu and Yap (2) requires some input parameters including the transient response and the threshold values for determining a certainty factor of odor detection. This method has complication in selecting the appropriate certainty factors and the threshold values, which should be different for different environmental conditions.…”

“…(1) Some works were carried out to model the response delay and considered it in the design of a source localization strategy. For example, Eu and Yap (2) developed a sensing method to overcome the long recovery time of a metal-oxide gas sensor using evidential theory. Shigaki et al (3) developed a sensing method to estimate the input timing using an auto-regressive with exogeneous input (ARX) model.…”

Palm-sized quadrotor source localization using modified bio-inspired algorithm in obstacle region

“…In a study [1], the validation of GSL performance was conducted in an open-space environment. The robot's ability to discover the gas source is an attractive topic with various proposed methods [2]- [5]. Implementing the GSL is a challenging engineering problem due to the frequently diluted gas distribution.…”