The document describes the design and study of an autonomous underwater vehicle (AUV) created by an Indian student. The goals of the project were to develop a low-cost AUV capable of autonomous navigation and position holding. The AUV uses a Raspberry Pi for processing sensor data from an IMU and GPS to navigate to programmed destinations and maintain position using proportional control of thruster motors connected to an Arduino. Software was created for a GUI interface and position control algorithm. The assembled AUV was tested for GPS navigation and position holding.

1. DESIGN AND STUDY OF AUTONOMOUS UNDERWATER VEHICLE
ROLL NO: CDS14M002 BY: CHETAN SONI GUIDE : Dr. S.R.PANDIAN
MOTIVATION
India being a peninsular country and has immense archeological sites
which are submerged in water, which provides an opportunity for underwater
exploration. Indigenously developed Autonomous Underwater Vehicles will
enhance the mapping and exploration capabilities of the vast coastlines of
peninsular India.
The existing system for underwater exploration is too costly and out of
researchers reach. The aim of this thesis is to develop a cost-effective
prototype vehicle that has the capability of autonomous operation in the
subsea environment. The tasks involved in autonomous driving are path
planning, navigation and position control.
OBJECTIVE
To develop an autonomous underwater vehicle which can drive itself to
point of interest and holds the position underwater
SYSTEM OVERVIEW
METHODOLOGY
The destination location and the corresponding point coordinates is
entered in the developed Graphical User Interface (GUI) in computer at boat.
The on board IMU magnetometer provides the heading direction of the
vehicle. The Raspberry– Pi processes sensor data, and generates command
signals to move the vehicle in appropriate direction, as per the path planned
by the system. The control signals from the Arduino are provided to the
Electronic Speed Controllers (ESC). The ESC’s provides sufficient current and
voltage to the BLDC motors to provide locomotion to the vehicle.
WORKDONE
Software system implementation
The algorithm of the implemented system is first user will insert the
destination GPS point as well as the depth it has to reach on GUI
(Graphical User Interface) as presented below, as the vehicle reaches the
destination point position control algorithm has been developed using
promotional controller to hold the position of the vehicle
Fig : Created GUI
Position Control
Hardware Implementation
All the processing of sensor signals is handled by Raspberry- Pi. Serial
communication between Arduino- Uno and Raspberry-Pi has been
established using Tx- Rx pin connections. Motor control signals are
handled by Arduino. IMU and GPS are directly connected to Raspberry- Pi.
Fig : Block diagram of the system
Thruster Specifications
S.No Characteristics T100 T200
1. Max thrust forward 2.36 kgf 5.1 kgf
3. RPM 300 – 4200 rev/min 300 – 3800 rev/min
4. Max Voltage 12 v 6-20 v
Current 11.5 amp 25 amp
Power 300 watts 350 watts
Electrical System Implementation
One of the major problems in underwater robots is deciding a proper
electrical distribution strategy which involves selection of tether cable (if
powering from the boat) selection of battery and regulation of voltage for
electronics components inside the hull.
Fig : Power board
Assembled Electronics Plate
Having high voltage components inside the hull with signal wires it
was increasingly tedious to keep and differentiate the placement of the
components on 9x25 cm acrylic plate.
To restrict electromagnetic interference among the components we
kept all the high voltage circuitry down side of the hull and all the low
voltage devices on the top of the plate, with this arrangement we achieve
negligible EMI effect.
Fig : Assembled Electronics Plate
Vehicle Design and implementation
Fig : Top and front view of AUV
Raspberry
– Pi
GPS
Destination point
IMU
GPS
Sensor
Motors
Orientation & heading
angle
Control Commands
Depth
Sensor
Arduino
Results and conclusion
 Design and development AUV frame has been done and tested
 GPS navigation implemented and tested on ground
 Position control using depth sensor data implemented and tested
Testing in larger water body has to be done
Implemented AUV
Applications
 Inspection of underwater artifacts with added camera and light
 Vehicle for various payloads such as SONAR, Underwater
manipulator
References
[1] H. Bohm and V. Jensen, “Introduction to Underwater Technology & Vehicle
Design”, by Marine Advanced Technology Education Center, Monterey
Peninsular College, 2004
[2] M. Shoab, K. Jain, M. Anulhaq and M. Shashi, "Development and
implementation of NMEA interpreter for real time GPS data logging,"
Advance Computing Conference (IACC), 2013 IEEE 3rd International,
Ghaziabad, 2013
[3] International submarine engineering web-based AUV design info. [online],
2016. Available: http://www.ise.bc.ca/auv.html
[4] Blue Robotics forum - https://forum.bluerobotics.com
[5] P. A. Miller, J. A. Farrell, Y. Zhao and V. Djapic, "Autonomous Underwater
Vehicle Navigation," in IEEE Journal of Oceanic Engineering, vol. 35, no. 3, July
2010
Fig. : System Overview
Fig. : System components
Fig. : Position control test
Signatures —
Student Guide
Current location