CleanSeas

• 

  Front view

• 

  Side/rear view

• 

  Close view of rear

Inspiration

Inspired by past projects in marine conservation as well as designs ranging from The Ocean Cleanup to CleanSpace orbital debris collection projects.

To tackle the challenge of collecting trash with a robot on the ocean, we decided to use a multitude of sensors and motors. We used a robotic arm with four degrees of freedom that was controlled by servo motors. We also used a water level sensor to track the water level, an ultrasonic sensor to track debris and trash, as a stepper motor that will be used as a propulsion system.

Seeing the use of robotics and autonomous systems to clean the ocean from trash and other pollutants gave inspiration for this project. Also, the level of software implementation needed to even function these cleanup robots gave a another pathway for this project.

What it does

CleanSeas is an intelligent ocean cleanup robot that detects and collects sizable pieces of trash while leaving marine animals, plants, and microorganisms alone.

How we built it

Our model is designed with Fusion360, soon to be undergoing design analysis in Autodesk CFD. Our software is programmed in C and uploaded to an Arduino Mega microcontroller. A Lafvin mechanical arm kit is used in this prototype to represent what the final version might look like.

1) Chassis

The chassis itself was designed with sustainability in mind. As opposed to other cost & resource prohibitive designs which use subtractive manufacturing for the chassis, the chassis itself here is made out of punched and rolled sheet metal. As many other cleaning designs have habitat concerns in mind, such as killing Plankton and other microorganisms, the holed design allows for such creatures to escape. Beyond this, the use of image-recognition to selectively grab trash will avoid accidentally trapping microorganisms.

For the rigidity of the chassis, this itself is not a structural concern as the current design is intended for surface use. Further work to include bulk-heads to account for pressure changes would be warranted if Z-axis movement is added.

Beyond this, the chassis was designed to maximize efficiency of the energy used during this grabber process. Computational Fluid Dynamics may be used to model and optimize the chassis design around this goal.

2) Propulsion & Steering

The propulsion for this device was designed around simple and consistent steering. At the rear of the vehicle is a 110 mm (diameter) custom designed propeller which provides nearly all of the forward thrust, driven by an AndyMark 775 Redline motor. This motor itself was chosen because of the balance of sustainable pricing (retail of $20), and performance curve at various RPMs. As the vehicle itself is meant to move slowly as to not disturb surrounding trash, the motor itself is stepped down in a custom 5:1 gear ratio planetary gearbox. The gearbox, motor, avionics, and power system are all isolated from the rest of the container with an air-tight seal.

The steering of this device is controlled by two 28BYJ-48 stepper motors on each side of the vehicle, with custom 21 mm (diameter) propellers to provide yaw of the side.

Further work in the vehicle would include a mechanism to intake water and compress inner air to provide z-axis movement.

4) Grabber System This grabber system is our main piece of equipment that will be collecting the trash. It is controlled by 4 servo motors. One for the base rotation, two for the arm bending/move back, and one for the claw grip. This provides a more precise way of collecting trash as this will specifically latch onto any trash that is detected within the robots vicinity and move it into the chassis.

Challenges we ran into

How to navigate underwater without endangering wildlife or destroying the hardware, how to develop a visualization algorithm that reliably distinguishes between jellyfish and plastic bags (when even turtles can't distinguish between them), how to maneuver underwater without pushing target trash away.

Accomplishments that we're proud of

Created a semi-working mechanical arm Implemented code for the water level and ultrasonic sensor Created a cad model of the chassis and other equipment for the project

What we learned

Learned how to implement various circuit designs to provide optimal power to the some of the components Implement serial monitoring on code that needed to provide information such as the current water level and object detection feedback The benefits of the individual types of motors, for example if you wanted a lot of speed, but with little amounts of torque 3V - 6V DC motors would be beneficial. If you’re trying to have more torque with sacrifice of speed, stepper motors would be the best solution. How coding in an Arduino IDE involves the use of C programming language. How to use Fusion360 and Autodesk CFD Ultimate: Due to technical issues, I was not able to access the CAD software I am most comfortable with, but in the end I learned how to use the Autodesk interface. Now I know the strengths and weaknesses of both programs. The pros and cons of different boat roll stabilizers. (we considered gyroscopic stabilizers, flat fins, and finally decided on vector fins. Our model is not yet optimized, but might work on the small scale of our robot.) We also learned about current projects in ocean trash pickup (such as the Ocean Cleanup), and somewhat similar initiatives such as space junk cleanup projects.

What's next for CleanSeas

Optimizing the body shape and propulsion mechanism for hydrodynamic performance and energy efficiency. Developing a reliable ML algorithm to distinguish between plastic and marine wildlife.

Built With

• arduino
• autodesk-fusion-360
• c
• cfd
• lafvin