Robosub

NURC SAUC-E

Date: 2012
Supervisor: Giuseppe Casalino
Institution: Università degli studi di Genova

For this project I was a part of a team of 5 people (Luca Buoncompagni, Raffaello Camoriano, Thomas Genevois and Gamal El Ghazaly). The purpose was to create and autonomous undewater vehicle (AUV) to compete at the 2012 NURC SAUC-E competition.

My main responsibilities were the development and implementation, connection and testing of all electronic components, including: power convertors, sensor data A/D conversion, actuators’ drivers integration and wiring. The main challenge was to optimally organise and connect all component in a confined waterproof space. Besides this, I collaborated with Thomas on the mechanical design and assembly of the overall structure.

"CRISTOFORO" Robot

Initial CAD model with main components:

COMPONENTS

The components used in the AUV which needed to be organised:

Power supply
- Batteries (4 Lithium-Polymer (LiPo), 6 cell, batteries)
- Emergency stop
- Power board
Devices
- Sensors (Doppler Velocity Log (DVL), Inertial Measurement Unit (IMU), hydrophones, top camera , webcam)
- Actuators (stepper motor and its controller, thruster motors and their drivers)
- Computation (PC104 and peripherals, Arduino)
Connectors
- Waterproof connectors
- Molex: motors & pressure sensor
- Battery molex + special
- Camera + hydrophones

Moreover, additional auxiliary structural components needed to be made to support all the devices. Particular care was taken when components were placed so they do not interfere and affect each others performance.

WIRING DIAGRAM

INSIDE THE TUBE

Component placement inside the tube and their actual fitting:

OUTSIDE THE TUBE

The biggest issue was ensuring the waterproofing of the tube, at its most vulnerable points – the connectors. The inside-outside connections were between the thrusters and their drivers. These connectors were custom made by putting motors’ large cables in the brass connector and sealing it off with a solidifying waterproof sealant.
However, this was the weak point which made the most problems, and is the cause why our team did not manage to prepare the AUV in time for the challenge.

POWER BOARD

This is the power board that I designed and produced in order to provide specific voltage/current demands for each of the components it supplies. Images with all connections attached and deployed in the tube are shown below:

CONNECTORS

The largest connectors which used up most of the space were the ones connecting the thrusters with their drivers. In order for the lid to be detachable, we used MOLEX connectors for easier attachment/detachment.