The MIT Robot Pike Project

Here at the MIT Towing Tank we are building robotic fish. The aim of these robots is to help us learn more about the complex fluid mechanics that fish use to propel themselves. In the long run, propelling small autonomous vehicles via fish-like swimming could have enormous energy savings, and increase the length of time a small machine could swim. In the mean time, by studying and building these robots, we hope to answer the paradox -- fish don't seem to have enough muscle power to propel themselves at the speeds that they do.

This project attempts to build a swimming Pike. The characteristics to be demonstrated are very quick turning and fast acceleration from a stop. In the wild, Pike accelerate at rates from 8-12 G's during a start from a standstill to 6 m/s. While we may not be able to achieve these wild numbers, half or a quarter of this accelleration would still demonstrate that flappingfoil propulsion is certainly capable of higher accellerations than a propeller.

What's better than one RoboFish?
Two or three RoboFish, and maybe some fast-swimming contraption fashioned after a penguin for good measure.

The bluefin tuna is a specialist in long-range swimming, and the pike and muskie excel in fast-starting and maneuvering. Hence the RoboTuna, the RoboPike, and the RoboMuskie. By creating robotic versions of natural born swimmers, researchers are exploring ways of improving speed and maneuverability for both ALIVs and boats. RoboTuna led the way, with its 2,843 parts, 40 ribs, segmented backbone and Lycra skin. Experiments with the 1.2-meterfish indicated that a single oscillating foil (the fish's tail) provides an unconventional, highly beneficial hydrodynamic mechanism for reducing drag in propulsion.

In contrast with the RoboTuna, the RoboPike, a freely swimming 70-centimeter autonomous robot, has a very simple design, for reliability and ease of use. It has demonstrated great agility in water, emulating the outstanding maneuverability of fish. In RoboTuna's wake came Proteus, the Penguin Boat, a 12-foot craft with two flippers attached to its stern. Proteus uses state-of-the-art robotics and allows researchers to study a wider range of flipper motion than RoboTuna. And Proteus could lead the way to redesigned full-scale ships that move far more efficiently and consume less fuel than those using conventional propellers.

And there are other offspring. In coordination with the Draper Lab and General Dynamics' Electric Boat Co. (Groton, Connecticut), MIT researchers are working to apply the bio-mimetic process to improve naval capability. And the SeaLion Project, an offspring of the RoboPike, is aimed at developing flapping foils to assist the maneuvering of rigid hull ships and submarines.