Soft robotic fish - Joseph DelPreto

Exploration of underwater life with an acoustically controlled soft robotic fish

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Collaborators: Robert Katzschmann, Robert MacCurdy, Daniela Rus

Closeup exploration of underwater life requires new forms of interaction, using biomimetic creatures that are capable of agile swimming, environmental sensing, and remote human operation. This project aims to design, fabricate, control, and test a remote-controlled soft robotic fish that can swim with natural motions to hopefully not disturb the marine life it observes.

The robotic fish exhibits a lifelike undulating tail motion enabled by a soft robotic actuator design that can potentially facilitate a more natural integration into the ocean environment.

SoFi Soft Robot Fish Close-Up in Coral Reed — Photo: Joseph DelPreto, MIT CSAIL

SoFi Soft Robot Fish With Real Fish in Coral Reef — Photo: Joseph DelPreto, MIT CSAIL

Acoustic communication

Using a miniaturized acoustic communication module, a diver can direct the fish by using a modified gamepad controller. The diver can send commands such as speed, turning angle, and dynamic vertical diving. Experimental results gathered from tests along coral reefs in the Pacific Ocean show that the robotic fish can successfully navigate around aquatic life at depths ranging from 0 to 18 meters.

SoFi Soft Robot Fish in Coral Reef Remote Controlled by Scuba Diver — Photo: Joseph DelPreto, MIT CSAIL

The communication system was designed to be very compact, facilitating integration into remotely controlled underwater operations. The system supports up to 2048 commands that are encoded as 16 bit words. A pulse-based FSK modulation scheme is implemented, along with a method of demodulation requiring minimal processing power that leverages the Goertzel algorithm and dynamic peak detection. All demodulation and processing is successfully executed in real time on an Mbed microcontroller that fits inside the head of the robotic fish. The communication was evaluated in a pool and in the open ocean.

Poster

Poster presented at the 2019 Capitol Hill Ocean Week Exhibition

Publications

R. K. Katzschmann, J. DelPreto, R. MacCurdy, and D. Rus, “Exploration of underwater life with an acoustically controlled soft robotic fish,” Science Robotics, vol. 3, iss. 16, 2018. doi:10.1126/scirobotics.aar3449
[BibTeX] [Abstract] [Download PDF]

Closeup exploration of underwater life requires new forms of interaction, using biomimetic creatures that are capable of agile swimming maneuvers, equipped with cameras, and supported by remote human operation. Current robotic prototypes do not provide adequate platforms for studying marine life in their natural habitats. This work presents the design, fabrication, control, and oceanic testing of a soft robotic fish that can swim in three dimensions to continuously record the aquatic life it is following or engaging. Using a miniaturized acoustic communication module, a diver can direct the fish by sending commands such as speed, turning angle, and dynamic vertical diving. This work builds on previous generations of robotic fish that were restricted to one plane in shallow water and lacked remote control. Experimental results gathered from tests along coral reefs in the Pacific Ocean show that the robotic fish can successfully navigate around aquatic life at depths ranging from 0 to 18 meters. Furthermore, our robotic fish exhibits a lifelike undulating tail motion enabled by a soft robotic actuator design that can potentially facilitate a more natural integration into the ocean environment. We believe that our study advances beyond what is currently achievable using traditional thruster-based and tethered autonomous underwater vehicles, demonstrating methods that can be used in the future for studying the interactions of aquatic life and ocean dynamics.

@article{katzschmann2018explorationsoftfish,
title={Exploration of underwater life with an acoustically controlled soft robotic fish},
author={Katzschmann, Robert K and DelPreto, Joseph and MacCurdy, Robert and Rus, Daniela},
journal={Science Robotics},
volume={3},
number={16},
elocation-id={eaar3449},
year={2018},
month={March},
publisher={Science Robotics},
doi={10.1126/scirobotics.aar3449},
url={https://robotics.sciencemag.org/content/3/16/eaar3449.full.pdf},
abstract={Closeup exploration of underwater life requires new forms of interaction, using biomimetic creatures that are capable of agile swimming maneuvers, equipped with cameras, and supported by remote human operation. Current robotic prototypes do not provide adequate platforms for studying marine life in their natural habitats. This work presents the design, fabrication, control, and oceanic testing of a soft robotic fish that can swim in three dimensions to continuously record the aquatic life it is following or engaging. Using a miniaturized acoustic communication module, a diver can direct the fish by sending commands such as speed, turning angle, and dynamic vertical diving. This work builds on previous generations of robotic fish that were restricted to one plane in shallow water and lacked remote control. Experimental results gathered from tests along coral reefs in the Pacific Ocean show that the robotic fish can successfully navigate around aquatic life at depths ranging from 0 to 18 meters. Furthermore, our robotic fish exhibits a lifelike undulating tail motion enabled by a soft robotic actuator design that can potentially facilitate a more natural integration into the ocean environment. We believe that our study advances beyond what is currently achievable using traditional thruster-based and tethered autonomous underwater vehicles, demonstrating methods that can be used in the future for studying the interactions of aquatic life and ocean dynamics.}
}

J. DelPreto, R. Katzschmann, R. MacCurdy, and D. Rus, “A compact acoustic communication module for remote control underwater,” in Proceedings of the 10th International Conference on Underwater Networks & Systems (WUWNET), 2015. doi:10.1145/2831296.2831337
[BibTeX] [Abstract] [Download PDF]

This paper describes an end-to-end compact acoustic communication system designed for easy integration into remotely controlled underwater operations. The system supports up to 2048 commands that are encoded as 16 bit words. We present the design, hardware, and supporting algorithms for this system. A pulse-based FSK modulation scheme is presented, along with a method of demodulation requiring minimal processing power that leverages the Goertzel algorithm and dynamic peak detection. We packaged the system together with an intuitive user interface for remotely controlling an autonomous underwater vehicle. We evaluated this system in the pool and in the open ocean. We present the communication data collected during experiments using the system to control an underwater robot.

@inproceedings{delpreto2015acoustic,
title={A compact acoustic communication module for remote control underwater},
author={DelPreto, Joseph and Katzschmann, Robert and MacCurdy, Robert and Rus, Daniela},
booktitle={Proceedings of the 10th International Conference on Underwater Networks \& Systems (WUWNET)},
organization={ACM},
year={2015},
month={October},
doi = {10.1145/2831296.2831337},
isbn = {978-1-4503-4036-6},
url={http://groups.csail.mit.edu/drl/wiki/images/f/f9/Delpreto-2015-A_Compact_Acoustic_Communication_Module_for_Remote_Control_Underwater.pdf},
abstract={This paper describes an end-to-end compact acoustic communication system designed for easy integration into remotely controlled underwater operations. The system supports up to 2048 commands that are encoded as 16 bit words. We present the design, hardware, and supporting algorithms for this system. A pulse-based FSK modulation scheme is presented, along with a method of demodulation requiring minimal processing power that leverages the Goertzel algorithm and dynamic peak detection. We packaged the system together with an intuitive user interface for remotely controlling an autonomous underwater vehicle. We evaluated this system in the pool and in the open ocean. We present the communication data collected during experiments using the system to control an underwater robot.}
}