Surface Water Waste Collection Robot

As a part of EPICS, I got the chance to conduct a study on the existing Waste collecting ASV's and design a fully autonomous and durable design with minimum cost on maintenance for IEEE SIGHT CEC.

Also, all the 3d printed parts shown in this entire project is designed from scratch and 3d printed by me.

This is an ongoing project, so suggestions and tips are appreciated.

Frame Essentials (f):

1. 12 X 30mm OD Hollow 1000mm Carbon fiber rods : Buy High quality and strong 3K Roll-wrapped Carbon Fibre Tube Hollow
2. Custom 3d printed joints .
3. Brass Inserts : M5X12MM Brass Insert.

Thruster (t):

1. 2 X 5X8 3d printed propellor ( made for initial prototype).
2. 2 X 3660 SURPASS waterproof BLDC : Buy SURPASS HOBBY- 3660 ROCKET sensoreless waterproof motor at best price.
3. 2 mm 1 meter square Sheet Metal plate.
4. 3d printed thruster mount.

Electronics (e):

1. Flight Controller: Pixhawk PX4 with power supply : Buy Holybro Pixhawk 4(aluminum case)&PM07 14S Set
2. Raspberry pi 5 : Official Raspberry Pi 5 8GB Starter
3. 2 X 80 A bidirectional ESC(Custom Made).
4. 30 Ah 3C Lithium iron phosphate Battery (Custom Made).

further onboard electronics are yet not confirmed.

Frame Design

The main frame of the ASV is made of (f).1 with dimension 1000mmX1000mmX420mm and uses (f).2 i.e 3d printed 3- and 4-way joints.

Total Volume of 440L, considering Buoyancy and floating nature of plastic the ASV is expected to collect 40 to 60 L of waste in a single run.

Propulsion System

Thruster Mounts: In the current stage the thruster is attached directly to the main frame on each side with 5 mm bolts

Steering Mechanism: Uses differential thrust

Hull design

Shape: As we are using a catamaran model ASV with 2 identical and symmetrical modular hulls.

Material Selection: At Stage 2 prototyping, as of now we are using a 1400mmX20mmX40mm 3d printed hull design (not tested/simulated) with epoxy to water seal the hull.

For Stage 1 prototype we used a 6-inch PVC pipe

Structural Analysis

As of now I just kickstarted Ansys fluent for the hull and structural dynamics Sim. Also, after stage 2 completion the tested files and sim data will be open-sourced :) <3.

For thrusters we initially used a 2836 750kv BLDC and for that used a 5inch diameter and 8inch pitch tri blade propellor(t).1.

Currently we are experimenting with newer propellors, and suggestion are appreciated.

Insight 1

Using an upper mounted gearmotor for actuation of an open and closable front flap.

Insight 2

Using a simple fit in place basket with partial enclosure which helps in an easy pull up mechanism to collect waste.

Insight 3

As mentioned in the structural design, we were only able to collect 40 - 60 L of waste so came up with an idea of an expanding back net helping to increase the active surface area there by increasing the potential volume of waste that can be collected.

Above is a 3d printed 1:10 scale of our project I made to present my design to the IEEE team.

Doubts:

1. Material Selection for Hull: Fiberglass/carbon fiber or simple 3d printed hull with epoxy to water seal, which would be better for our use case.
2. Propellor Design: Considering the size of the ASV what the preferred pitch and diameter of the propellor?
3. Thruster Mounting Location: In the miniature design also, we were not able finalize the position for thruster that would result in better efficiency for the ASV.

Stage 1 prototype was used to experiment with different motors, propellors, speed and buoyancy.

Team Members (prototype making):

1. Jerrin Shibu (me, back left), 4th year CEC
2. Vignesh J R (front right), 3rd year CEC
3. Vijay Satheesh, 3rd year CEC
4. Yoham CM (front left) ,4th year CEC
5. Bhavesh Sanjay (camera guy <3), 3rd year CEC
6. Jeffin Shibu (back right), my mentor & postgraduate, IITM