Embedded Files
Scripps Autonomous Fish
Scripps Autonomous Fish
Sponsored by Dr. Jules Jaffe at the Scripps Institute of Oceanography
Sponsored by Dr. Jules Jaffe at the Scripps Institute of Oceanography
Background
Background
Autonomous Underwater Vehicles, or AUVs, are a commonly utilized tool in the field of oceanography. Used to observe and record environments otherwise inaccessible to humans, these robots are essential to our understanding of oceans today. Dr Jules Jaffe at the Scripps Institute of Oceanography has been exploring the limits of these vehicles for many years at the Jaffe Laboratory for Underwater Imaging. With a diverse number of projects focusing on visual and acoustic observation of underwater life, Dr Jaffe’s research leads the way in ocean imaging technologies. Dr Jaffe now seeks to expand oceanography to a wider audience by creating a low-cost Autonomous Fish. Designed to serve as both an outreach tool to students and a low-cost observational platform, this project intends to create a quiet and open-source AUV with low hydrodynamic impacts. Mounted with a high resolution camera and an onboard controls system, the fish will be perfect for easily viewing ocean life in its natural habitat.
Autonomous Underwater Vehicles, or AUVs, are a commonly utilized tool in the field of oceanography. Used to observe and record environments otherwise inaccessible to humans, these robots are essential to our understanding of oceans today. Dr Jules Jaffe at the Scripps Institute of Oceanography has been exploring the limits of these vehicles for many years at the Jaffe Laboratory for Underwater Imaging. With a diverse number of projects focusing on visual and acoustic observation of underwater life, Dr Jaffe’s research leads the way in ocean imaging technologies. Dr Jaffe now seeks to expand oceanography to a wider audience by creating a low-cost Autonomous Fish. Designed to serve as both an outreach tool to students and a low-cost observational platform, this project intends to create a quiet and open-source AUV with low hydrodynamic impacts. Mounted with a high resolution camera and an onboard controls system, the fish will be perfect for easily viewing ocean life in its natural habitat.
Objective Build an affordable, open source, small, and quiet autonomous fish. The key design goals are the following:
Small: less than 20cm in length
Quiet: will not disturb wildlife that was being studied
Minimum camera quality of 780p
Clear documentation
Low-cost
Final Design
Final Design
The AUV moves utilizing a single stepper motor to actuate six tentacles attached around the rim of the circular housing. In a single movement cycle, the stepper motor first quickly turns, using polypropylene string to pull and compress the tentacles together, forming a jet of water. This power stroke propels the robot forwards. In order to return to the open tentacle position without moving backwards, the motor slowly rotates back, taking advantage of the elasticity of the tentacles to actuate the recovery stroke. In order to control the direction of the AUV, two planetary gears weighted with 375g rotate inside the housing, changing the AUV’s center of mass.
All parts, with the exception of the laser cut gaskets, 3D printed housing, and machined double O-ring seal, are off-the-shelf and open source items. The final size of the robot is 18x18x28cm, and the total cost of raw materials for a single unit is less than $500. The robot is can be used in both open bodies of water and closed aquariums, and is fully functional in salty ocean water. The SD card installed in the Raspberry Pi can hold enough video data to last an entire mission, in addition to the operating system, code, and sensor data needed to run the robot.
Overall, the AUV works well, although the mobility of the design could use improvement. The robot does not actuate efficiently through water, and some design components cannot be used simultaneously due to incomplete coding. Despite installation of the camera and microprocessor, the visual controls system was not coded and implemented due to time constraints, and therefore the robot cannot effectively maneuver to follow an object. However, despite these shortcomings, the robot was constructed in an open source manner, so any future students with the time and resources can build upon the basis created. The AUV successfully achieves the autonomous, low-cost, small, quiet, open-source, and high camera quality functional requirements of the original proposal, and with additional time could be improved to maneuver well enough to achieve the visual tracking goals of the sponsor.
Performance Results
Overall, the performance of the design could use improvement. The AUV does not actuate effectively through water, and design components cannot be used simultaneously due to incomplete coding. Despite installation of the camera and microprocessor, the visual controls system was not coded and implemented due to time constraints, and therefore the robot cannot effectively maneuver to follow an object. However, despite these shortcomings, the robot was constructed in an open source manner, so any future students with the time and resources can build upon the basis created. The AUV successfully achieves the autonomous, low-cost, small, quiet, open-source, and high camera quality functional requirements of the original proposal, and with additional time could be improved to maneuver well enough to achieve the visual tracking goals of the sponsor.
Project Documents
Click here to see the executive summary, final report, and poster regarding this design
Page updated
Report abuse