Project Mehen was an internal project I did together with Sascha Fechner and Jan Albiez at the DFKI in Bremen. We wanted to explore the concept of a snake-like robot for underwater environments. The Mehen robot is comprised by a series of battery and actuator compartments that provide distributed energy storage and movement capabilities in two axis per compartment. As actuators we used high-torque servo motors that are controlled by a central microcontroller unit in the robots head segment. The directional, higher-level control is done via a radio link using a frequency in the low megahertz range to allow sufficient depth penetration of the radio waves in water. The low-level pattern generation is done on-board by the central microcontroller unit. In addition, the head segment of the robot is equipped with a camera system to allow inspection of underwater structures. The overall size of the robot is 125cm in length and 8cm in diamenter while weighing 4.3 kg. The battery capacity is 96Wh supporting long-duration operation with one charge. Its skin is comprised of a neoprene cloth treated with a latex-based composite.
Besides the engineering and control aspects we investigated how undulating movement patterns can be used for propulsion in environments that are sensitive to disturbances. One possible use case would be environmental monitoring in swamps or the bank areas of rivers.
References
1
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Underwater Robotic Snake,
In: Internal DFKI project, 2007,
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