Design and Testing of a Long Endurance Coastal Monitoring Robotic Platform

Abstract

About 600 million people reside along the coasts at an elevation of fewer than 10 meters above sea level [10]. In addition to being critical to human society, biodiverse coastal habitats such as estuaries, wetlands, coral reefs, and upwelling areas support and provide breeding grounds for organisms such as fish, marine mammals, sea turtles, and migratory birds. Given the role the coasts play in billions of lives, monitoring this highly dynamic environment is an urgent concern for safety and conservation efforts. To better understand anthropological impacts and natural fluctuations of coastal waters, it is necessary to develop a coastal monitoring system that can be deployed non-invasively and cost-effectively. However, surveying the coastal waters is not an easy task. Coasts are affected by a unique mix of environmental and human influences that vary over time. These influences range from natural erosion and accretion to substantial coastal engineering. Individual coastal sites can be challenging to reach and may have considerably different needs and vulnerabilities [7], [5].The diverse conditions along the coasts create a complicated environment for any observation system to navigate. Within this environment, there is space for new and inexpensive approaches to coastal monitoring. Researchers need an affordable and reliable method of data collection to understand this critical area further. A source of high-frequency coastal environmental data provides an opportunity for an accurate analysis of the highly dynamic coastal ecosystem. Some of the most vital data is the hardest to obtain, that is, highly dynamic parameters that exist during transient events, such as during or shortly after hurricanes, landslides, algae blooms, severe weather and other significant meteorological or oceanographic events. This kind of data is currently impractical to collect due to the risk it poses to data collectors. For instance, during extreme scenarios such as hurricane landfall, capturing transient event data is crucial for the proper development of local coastal models, but it is dangerous or impossible for people to deploy manual sensors.The ideal data collection system needs to be economical, reliable, non-invasive, and capable of surviving highly dynamic coastal environments. Our solution is a fully autonomous, cable-mounted mobile platform that will pull itself along a cable partially submerged along the coast. The platform locomotes under its own power along this cable to enter and exit the water and autonomously collects data along its path. By simplifying the motion of the robotic system to a single degree of freedom, it can easily overcome the many challenges of navigating a coastal environment.The ultimate goal of this system is to deliver water quality data to a remote operator, therefore, it must operate in the field without a human operator present for extended periods of time. To extend deployment times, an inductive charging system situated above water is designed to recharge the robots batteries. In order to reach such a charging station, the robot must be able to move above the surface of the water. This paper explores a redesign of the robot for movement out of the water as well as the implementation of the aforementioned charging system.