Design, development, and testing of a multi-agent autonomous surface fleet for environmental applications

As costs have decreased and both computational complexity and robustness have increased, the use of autonomous vehicles in real-world environments has increased dramatically. The development of a fleet of autonomous surface vehicles able to coordinate their actions through communications provides a significant tool for numerous water-based applications such as the reduction of predatory birds on aquaculture ponds, tracking of pollutant gradients, and water quality mapping applications. A fleet of three autonomous surface vehicles (ASVs) was developed using the best characteristics from earlier designs. Each vehicle is a dual-pontoon, dual-paddlewheel design powered by batteries recharged using a vehicle-mounted solar array that produces a peak output of 30 Watts. The control system consists of two microcontrollers: a TS-7260 ARM-based microcontroller board that handles high-level functions such as navigation, the collection, storage, and analysis of data, and communication; and a BASIC Atom Pro that handles motor control. A major design goal was modularity. This allows for quick and easy field repairs and upgrades. Communication is essential for fleet success. The dual-microcontroller system in these ASVs has two levels of communication. Intra-ASV communications are handled via serial connections between the ARM and the BASIC Atom Pro on each ASV, whereas inter-ASV communications use XBee Radio Modules with an approximate range of 300 meters. Through the use of relaying, we have an effective range of 600 meters across the fleet of three ASVs. Longer-ranges are possible with other radios. It is desirable to know at all times where the ASV is both with respect to the other ASVs in the fleet and to the data being collected. By collecting and storing GPS coordinates on a regular basis and especially when a sample is taken, we have the ability to map the data being collected. Maps were constructed demonstrating the potential 50-80% reduction in birds. The development of the fleet of ASVs provides a novel, inexpensive, highly configurable, mobile platform for experimentation. Future research possibilities exist of significant importance including: gradient tracking of pollutants for both point source and non-point source pollutants; coastal applications including salinity mapping and bathymetry mapping; ecosystem monitoring; biosecurity applications; and others

Communications, Decision-Making, and Interactions of a Multi-Agent Autonomous Vehicle System

Autonomous vehicles are becoming ever more common and offer many attractive benefits to society. They can operate for long periods of time unattended, operate in environments that may be dangerous to humans, perform time consuming or repetitive tasks and all with greater efficiency and lower costs than humans. For these vehicles to be able to do these things, algorithms need to be designed and optimized that allow them to interact with the real-world environment in safe, effective, and efficient ways. We designed and built a set of three homogeneous water-based autonomous surface vehicles equipped with appropriate sensors and communications ability along with algorithms designed to allow these vehicles to perform various cooperative tasks using data obtained from the vehicles’ sensors and data shared between the vehicles. These vehicles were designed to be modular, economical, and, where possible, were constructed using off-the-shelf technology with programming designed to take advantage of these systems. When the COVID-19 pandemic put an end to lab and field work the physical vehicles were stored but the research continued utilizing a hybrid hardware-software simulation of the system. Three microcontrollers identical to the devices controlling the physical boats were attached via a Universal Serial Bus (USB) hub to a desktop computer running a simulated environment written in Python™. The three vehicles (microcontrollers) were given tasks including patrolling adjoining areas of the water body delineated by latitude and longitude boundaries while staying within their own boundary and avoiding collisions with the other vehicles. Initial testing was successful with the algorithm able to maintain the vehicles within their boundary \u3e=95% of the time with no collisions. Additional problem types including parallel travel; wind and current challenges; and gradient tracking and relevant algorithms are discussed

Efficient Passive Clustering and Gateways selection MANETs

Passive clustering does not employ control packets to collect topological information in ad hoc networks. In our proposal, we avoid making frequent changes in cluster architecture due to repeated election and re-election of cluster heads and gateways. Our primary objective has been to make Passive Clustering more practical by employing optimal number of gateways and reduce the number of rebroadcast packets