Autonomous Underwater Vehicle:

Autonomous Underwater Vehicle: Milestone #3 Design Review Group 4 Victoria Jefferson Reece Spencer Andy Jeanthanor Yanira Torres Kevin Miles Tadamitsu Byrne

Preliminary Rules released!!! • Theme: RoboLove • New addition • Torpedo Launcher • Similar Tasks • Validation gate • Orange Path • Marker Dropper • PVC Recovery • Acoustic Pinger • Same weight and size constraints as previous years • Must weigh under 110 pounds • Six-foot long, by three-foot wide, by three-foot high

Conceptual Design

Major Components of the System

Overview

Motors/Thrusters

Motors/Thrusters SeaBotix SBT150: • Chosen for functional ability and water resistance as well it’s built-in motor controller, voltage regulator, and low power consumption • Four thrusters will be placed on the AUV in a configuration that will allow for forward/reverse powertrain, left/right turning and depth control • Similar to BTD150 but includes motor controller

Motors/Thrusters Motor Controller: • Built-in voltage regulators • Automatic shut-off if it receives less than 20V DC and more than 30.1 V DC • Wiring configuration calls for 14-gauge power wire as well as Data and Clock inputs that utilize 18-gauge wire Power Consumption/ Placement: • Max Amp.: 5.8A(30 sec duration) • Max Cont. Amp.: 4.25A • Max Power: 150W(each motor) • Thrusters located on left/right for turning and bottom/front for balance and weight distribution

Risks Associated with…

Batteries

Vehicle Power System Batteries • Two 14.8 V DC batteries in series • Built-in PCM maintains a voltage between 20.8 V and 33.6 V • PCM prevents a drain of anything greater than 40A • Charge time = 10.1 hours • 30 min wait time is required after charge to allow PCB to evenly distribute cells in the battery

Batteries Components: • Hercules Switching Regulator • Up to 40V input • Outputs 5V, 6A • Used for “USB” power for onboard components • Switching allows for over %70 efficiency • All components connected with inline fuse rated at peak amperage consumption

Hydrophones • SensorTec SQ26-01 hydrophone • Full audio-band signal detection and underwater mobile recording • Operates at required sound level (187 decibels) • Performs in required range of the pinger (20-30 kHz) • Chosen over Reson TC4013 because it is more cost-efficient and provides the functionality we need

Hydrophone Configuration • 4 hydrophones will be utilized to determine the location of the pinger • 2 hydrophones will be placed horizontally to determine direction • The other two will be vertical in order to determine the depth

Inertial Measurement Unit (IMU) • Navigation/Stability Control • PhidgetSpatial 3/3/3-9 Axis IMU • Accelerometer: measure static and dynamic acceleration (5g) • Compass: measures magnetic field (±4 Gauss) • Gyroscope: Measures angular rotation (400°/sec) • Chosen for low cost and because it contained a compass instead of magnetometer unlike other IMUs

Camera Housing Analysis Stress Tensor (Pa) Total Deflection (in) • PVC piping • Viewing lens • Aluminum Plate

Cameras • Cameras chosen: • 3 Unibrain Fire I CCD webcams • Originally chose a Dynex webcam as well • Needed for light/color and shape recognition • CCD camera chosen for ability to operate in low light conditions • The cameras chosen for cost efficiency as well as compatibility with our software

Cameras • Positioning • Forward facing CCD camera for floating objects • Downward facing CCD camera for objects on the pool floor • Overhead camera for shape recognition • Housed in watertight casing to protect from water damage

Software for Sensors • Hydrophones • In the process of finding a Linux software capable of processing and managing data • IMU • RS-232 interface • Visualization and Configuration Software: SmartIMU Sensor Evaluation Software • Linux C Source Code • Cameras • Digital Image Processing using MatLab

Microcontroller The BeagleBoard: • Main Computer • OMAP 3530 Platform • USB/DC Powered • 2GB NAND Memory • 1GB MDDR SDRAM • Additional memory can be added (if necessary) • A 6 in 1 SD/MMC connector is provided as a means for expansion • UART

Microcontroller Software: • Operating system will be a Linux distribution • Ubuntu, Angstrom and Debian-GNU are the current choices • Mission code will be written in a combination of C/C++ • Program will receive data from sensors as input • Output will be sent via PWMs to the motor controllers to drive the motors • Program will be decision based using mostly if-else statements and loops

Mechanical Grabber • Used to complete the final task of the mission • Grasp and release mechanism located at the bottom of the AUV • Our design will depend on the size and orientation of the rescue object • The current design is to have a mechanical claw attached to a solenoid that will attach to an object in the water

Marker Dropper • Use to complete tasks in which a marker must be dropped • Will be machined out of aluminum • Utilize waterproof servomotor that will rotate marker dropper mechanism to release markers • Traxxas servomotors will be used • This method was chosen because it was the most cost efficient

Frame Overview • Simplistic Design constructed of 80/20 Aluminum • Allows for easy adjustability • 80/20 is structurally sound and can support all components of the AUV • The design mitigates vibration and will reduce hydrophone interference • Hull will be placed within the frame

Hull Overview • Hull consists of a watertight Pelican Box • Purchasing Pelican Box is simpler than designing watertight housing and is also inexpensive • Hull will house all onboard electronics • Reduces the risk of water damage to electronics • Exterior components will be connected via Fischer connectors

Schedule

Fall Semester Goals/Accomplishments • Select and design major components • Thrusters, battery, camera, electronics, connectors, motors, hull, frame, programming language, pseudo-code and software (mission tasks and sensors) • Still need to finish design of marker dropper and mechanical grabber, pseudo-code (sensors), and write software (mission tasks), verify that software is compatible with each other • Design and build AUV Hull • Design and build mounting brackets

Spring Goals • Write the programs for all subsystems • Test and debug • Color/shape recognition, sound detection, mechanical grabber and marker dropper, depth control • Integrate all subsystems into AUV • Full scale testing

Budget

Summary of Major Risks:Technical, Schedule, Budget

References • Official Rules for 2010 competition: • "Official Rules and Mission AUVSI & ONR's 13th Annual International Autonomous Underwater Vehicle Competition." AUVSI Foundation. Web. Sept.-Oct. 2010. <http://www.auvsifoundation.org/AUVSI/FOUNDATION/UploadedImages/AUV_Mission_Final_2010.pdf>. • Barngrover, Chris. "Design of the 2010 Stingray Autonomous Underwater Vehicle." AUVSI Foundation. Office of Naval Research, 13 July 2010. Web. 09 Nov. 2010. <http://www.auvsifoundation.org/AUVSI/FOUNDATION/UploadedImages/SanDiegoiBotics.2010JournalPaper.pdf

Autonomous Underwater Vehicle: