Linda Benedict, Hall, Steven G. | 2/29/2012 11:29:57 PM
Steven Hall, Daniel Smith, Brian Thompson and Jake Farlow
Automated, solar-powered boats have been used to reduce bird predation on catfish ponds and to track water quality in natural water bodies and drinking water reservoirs. Recent work has focused on using more than one vehicle at a time to more effectively perform agricultural and environmental tasks. Work on communication systems and procedures to coordinate actions of multiple vehicles is an area of current development.
A team of researchers at the LSU AgCenter developed a fleet of autonomous boats originally designed to reduce predatory birds on aquaculture ponds. These devices are modular, solar-powered and GPS-equipped and are controlled by microcontrollers. Dual Styrofoam flotation pontoons connected with an aluminum frame provide a stable base on which to mount solar panels, paddlewheels, electronics and other components.
The solar panels are located on top of the aluminum frame to collect energy during daylight hours and to protect electronics from the sun’s heat. Motors with paddlewheels are attached to each pontoon for moving and steering. Each boat is also equipped with batteries for energy storage. Cameras attached to the boats and paired with the microcontroller are capable of spotting predators. All electronics are stored in a large, sealable PVC tube in the boat’s center to prevent water damage.
Additional sensors to detect battery voltage and sunlight level allow the boat to turn off at night or during low power periods (such as repeat ed cloudiness). These sensors allow the boat to operate for weeks without maintenance.
At the head of the boat, there are GPS receivers capable of receiving accurate position and time information. The microcontroller can interpret this information to determine the speed and heading of the boat. At the tail of the boat, antennas are capable of communicating with other boats in the area, and the microcontroller can use information sent from other boats coupled with information on the local boat to establish a plan of action. For instance, if one boat detects a flock of birds on the water, Boat A can send a signal to Boats B, C and D. The system can be programmed to make a decision based on the situation so that in this case Boat A "calls for help," and Boats B and C come to assist Boat A in scaring off birds while Boat D continues to survey another area.
The future of the autonomous fleet of boats could include monitoring environmental quality of air and water from lakes, rivers, aquatic ponds and coastal regions. Use of such devices may include deployment in difficult-to-access areas to capture environmental, aquacultural, water reservoir or even off-shore data. The vehicles are stable and capture data effectively, and they can be included in a feedback system to provide control, alarm or information to improve water-quality management in coastal areas.
Each boat in the fleet is capable of two types of communication – internal to each boat and external between vehicles in the fleet. Boats are able to complete tasks that have been assigned before deployment and even during deployment, according to the data that have been sent back to a base station. The communication between the boats and a control station plays an integral part of the effectiveness of the fleet. The availability of multiple communication options for transmitting data to the central computer allows systems to be customized to meet individual farmer’s exact needs.
Each boat is equipped with GPS technology that can be programmed so a boat can remain within defined boundaries or be sent to a specific location. Applications could include mapping, environmental monitoring (spills, gradient tracking, temperature, oxygen level) and the use of biosensors. For instance, a fleet of boats equipped with sensors can be sent into a hazardous spill area to identify conditions where it would be unsafe for humans. The fleet, using internal and external communications, would gather data and send it back to the base station for analysis. Systems can be programmed to send alarms or report site conditions by contacting a computer, telephone, radio or pager.
Many areas of autonomous vehicle development and research offer opportunities. The AgCenter has developed and tested this concept and proved the devices can be highly effective at reducing bird predation on selected aquaculture ponds. They are effective, safe and environmentally friendly. Such devices likely will increase in their usefulness in coming decades, and most of these developments will have beneficial effects on fisheries and aquaculture, if wise management and design are considered.
Steven Hall, Associate Professor; and Daniel Smith, Brian Thompson and Jake Farlow, students, Department of Biological & Agricultural Engineering, LSU AgCenter, Baton Rouge, La.
(This article was published in the winter 2012 issue of Louisiana Agriculture magazine.)