Potential Fields Navigation of Lifeguard Assistant Robot for Mass Marine Casualty Response
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This thesis creates and implements an algorithm to enable the commercially available Emergency Integrated Lifesaving Lanyard (EMILY) lifeguard assistant robot boat to autonomously move towards marine victims. To achieve this, an attractive artificial potential field with GPS input was implemented. Currently, lifeguards working to save Syrian refugees crossing into Greece teleoperate EMILY to people in the water, but due to restricted depth perception, often overshoot and collide with the victim. The research benefits the safety, security, and rescue robotics research community. In addition, there are two societal benefits. One is that if EMILY can autonomously refine its navigation towards those in the water, the victims have a higher likelihood of quick rescue. Second, is that it would free the lifeguard to rescue victims in higher states of distress while the robot autonomously navigated to less vulnerable victims. Risks include the difficulty of data collection in open water, due to weather conditions. The system was demonstrated at a two locations: 12 runs at a pond in John Crompton Park and 7 runs at Lake Bryan. Trials were conducted at a range of 30 meters at the pond and a range of 100 meters at the lake. During the close range experiments, the magnitude profile implemented on the artificial potential field was varied between a constant profile, a linear profile, and an exponential profile. Each profile was tested from all four quadrants surrounding the goal. During the far range experiments, the magnitude profile was again varied, with the addition of different exponential profile. The goal radius was also varied in these trials, between 2 meters and 1 meter from the goal point. The velocity profile of each run was then examined. Ideal behavior is fast operation farther away from the target and slow operation near the target. Therefore the ideal velocity profile would have a steadily decreasing speed as the distance to the goal decreased. In both the close and far range trials applying an exponential magnitude profile to the artificial potential field implementation showed a roughly linear decrease in velocity as EMILY approached the goal- displaying the desired behavior.
Schofield, Rebecca T (2018). Potential Fields Navigation of Lifeguard Assistant Robot for Mass Marine Casualty Response. Undergraduate Research Scholars Program. Available electronically from