Sediment Sampling in Estuarine Mudflats with an Aerial-Ground Robotic Team

Abstract

This paper presents a robotic team suited for bottom sediment sampling and retrieval in mudflats, targeting environmental monitoring tasks. The robotic team encompasses a four-wheel-steering ground vehicle, equipped with a drilling tool designed to be able to retain wet soil, and a multi-rotor aerial vehicle for dynamic aerial imagery acquisition. On-demand aerial imagery, properly fused on an aerial mosaic, is used by remote human operators for specifying the robotic mission and supervising its execution. This is crucial for the success of an environmental monitoring study, as often it depends on human expertise to ensure the statistical significance and accuracy of the sampling procedures. Although the literature is rich on environmental monitoring sampling procedures, in mudflats, there is a gap as regards including robotic elements. This paper closes this gap by also proposing a preliminary experimental protocol tailored to exploit the capabilities offered by the robotic system. Field trials in the south bank of the river Tagus’ estuary show the ability of the robotic system to successfully extract and transport bottom sediment samples for offline analysis. The results also show the efficiency of the extraction and the benefits when compared to (conventional) human-based sampling.

Evaluation of Sampling Methods for Robotic Sediment Sampling Systems

“…However, due to the limitations of the electric thrusters, the penetration depth of the sediment in field experiments was limited to approximately 0.16 m [10]. Another study explored cooperation between human operators and robotic teams for sampling along the shoreline [21]. For this system, an operator decides which specific area to sample based on images from a high-resolution camera (similar to [9], above), attached to an Unmanned Aerial Vehicle (UAV) instead of an ROV.…”

An Affordable Vehicle-Mounted Sensing Solution for Mobile Air Quality Monitoring

“…Although spatiotemporal sampling of environmental variables can be achieved by means of tele-operated and autonomous mobile robots [6], [7], costs and risks can be reduced if the sensors are moved across the city on existing public transportation vehicles. The ExpoLIS project aims exactly at exploiting the natural advantages of existing public transportation infrastructures by developing an affordable AQ exposure sensing system composed by a network of sensor nodes deployed on city buses.…”

Simultaneous Deployment and Tracking Multi-Robot Strategies with Connectivity Maintenance

“…Considering the low battery life of the aerial robots, in [ 2 ], a group of them is assisted by a team of ground robots so that they can dock and recharge their batteries. Some authors focus on particular applications such as mobile sensory systems for monitoring environmental variables in greenhouses [ 3 ], instead of large sensor networks, or sediment sampling in estuarine mudflats [ 4 ] with drilling ground vehicles and aerial imagery robots.…”