Autonomous Underwater VehicleSponsor: NAVSEA Keyport Mentor: Mike KapusBen Brand, Kendra Brower, Joe Langevin, Jeffrey Le

To power our vehicle, wehave chosen Lithium Polymer batteries for their exceptional power density. LiPo batteries are volatile if not carefully monitored, so we have integrated a multi-stage battery monitoring system to ensure the safety of those interacting with the vehicle.

Impact Analysis

AcknowledgementsWe would like to recognize the following individuals and companies for helping us make this project successful:

Mike Kapus & NAVSEA Keyport, Dr. Patrick Pedrow, Cindy Zimmerman, Ning Hsu, Jack Hagemeister, John Yates, Kirk Reinkens, Miles Pepper, Kurt Hutchinson, Digilent, and Clippard Pneumatics.

We sincerely appreciate their contributions to making this project a success! We could not have done it without them!

Objective

PowerOur objective was to build an autonomous underwater vehicle capable of navigating an obstacle course via the utilization of:

Image Recognition Acoustic Localization Torpedo Launching Markers Dropping Object Grasping

The vehicle will compete in the international RoboSub competition which takes place in San Diego, CA in July. Our task was to design and build the mechanical and electrical aspects of the vehicle while a Computer Science senior design team was responsible for the vehicle’s image recognition software.

Navigation

Our navigation system allows the submarine to be aware of its depth, orientation, and heading at all times. We built an array of sensors including an accelerometer, gyroscope, depth sensor, and compass which are used in our navigation algorithm to accurately maneuver the vehicle.

Vision

In order to navigate the obstacle course, our AUV must recognize and react to its surroundings. It accomplishes this using a forward and downward facing FireWire cameras. The video stream is sent to our computer where it is analyzed and used to make operational decisions.

ClawsOur AUV is required to grasp andrelease multiple objects positionedin various orientations. We have multiple claws designed to handle each unique scenario. These claws extended from beneath the sub via a 14” pneumatic piston and are retracted when the task is

Torpedo LauncherOne aspect of the

competition involves firing torpedoes at various sized

targets. Our solution involved using

SolidWorks to design a torpedo with neutral

buoyancy and a center of mass about the torpedo’s

geometric center. As a result, the torpedo will maintain a

constant heading without pitching upward or downward.

It was 3D printed to fit perfectly inside a short PVC barrel and

is launched using a pneumatic piston. Our maximum target

distance is approximately 8 feet.

AcousticsAcoustic signals are captured through anarray of three hydrophones and processed through analog circuitry. This circuit outputsthree signals which are interpreted by an FPGA which uses phase differences to determine the approximate location of the acoustic source. The FPGA then relays this information to the onboard computer via serial communication.PneumaticsMarker Dropper

The task of the marker dropper is to deposit payloads into specifically labeled bins. We accomplish this using a 3D printed mechanism and a pneumatic piston. The piston pushes and pulls a sliding “trap door” which releases a 1” steel sphere.

Inside our pressure case is an array of subsystems and sensors which need to communicate with a central computing device. To establish this communication, we designed a PCB which mates with a commercial microcontroller board. Our PCB has over 30 connectors which mate with our accelerometer, gyroscope, compass, computer, leak detector, power supply, depth sensor, motor controllers, and solenoids.

The AUV utilizes a pneumatics system powered by a 48in3 paintball tank at 3000 PSI. This pressure is then regulated down to 100 PSI and distributed into 10 solenoids through a series of manifolds. These solenoids control the air flow to different aspects of the submarine including the marker dropper, torpedo launcher, and grasping claws. All of our pneumatics equipment was generously donated by Clippard Minimatics.

ThrustersOur submarine uses six thrusters to maneuver through the obstacle course. The thrusters use just 19.1v at 4.25A to produce a maximum continuous thrust of 4.85 ft-lbs.

Recommendations

Safety Precautions

Since water and electricity do not mix, we have implemented a variety of safety precautions to ensure the health and wellbeing of those interacting with the sub. These precautions include:

Emergency Kill Switches Fuses Leak Detection Roll Detection Battery Monitoring

Future work for this AUV will involve improvements in efficiency by developing methods to use less air, power, and weight. The most effective way we can reduce the weight of the vehicle is to use a smaller pressure case.

As a first year team, using a large Pelican case simplifies construction but results in increased buoyancy, thus requiring us to add weight to achieve neutral buoyancy. Additionally, initiatives to consume less power include improving the efficiency of the image processing code and using high-efficiency voltage regulation.

Submarine Design & Subsystems Signals & Communications

Team Lamarr

Through the design and construction of our AUV, we will impact the world in a variety of positive ways. From a societal perspective, our AUV may inspire fellow engineers to invent devices which improve people’s quality of living. From an economic perspective, inspiring engineers may also lead to financial growth in the field of robotics. Additionally, many of the components used to build an AUV are manufactured in America, thus supporting the American economy.

From a global perspective, many robotic components contain rare earth metals which are primarily mined in China. Utilizing parts containing these metals could potentially be contributing to geopolitical tension between the United States and China. Furthermore, the utilization of these resources supports China’s mining efforts which are known to be detrimental to the environment.

While autonomous submarines can benefit our nation’s military, they can also be used for non-combative purposes. For example, from an environmental perspective, the technology we develop can be used to clean up oil spills and even perform non-intrusive “check ups” on the habitats of reef or deep sea creatures without direct human contact.

completed.