A IRCRAFT C ARRIER D RAFT M EASUREMENT Introduction Newport News Shipbuilding partnered with Old Dominion University to develop a draft measuring system for use on naval aircraft carriers Draft Overview Shift Draft: Ship draft is the vertical distance between the keel and the waterline. Draft is used to estimate the weight of cargo on board, by calculating the total displacement of water and applying Archimedes Principle. The current method of draft measurement is to visually inspect the waterline markings on the ship. This process is accurate up to 1 By improving draft measurement, the ship weight can be more accurately determined. Design Specifications: 1/8 th inch accuracy Economical Portable Wireless Reduce risk to personnel Non-permanent mounting Ultrasonic Overview Our system utilizes a sonic range finder: The ultrasonic range sensor sends a high frequency (42kHz) sound wave toward the water surface. The wave is then reflected back to the sensor. The distance from the sensor to the water surface is calculated based on the time of flight of the sound wave. Electronics System MaxBotix Ultra-Sonic High Performance Rangefinder: 42kHz frequency 195 inches maximum range F temperature range Real-time calibration voltage, humidity, ambient noise Arduino Micro Controller Board 32kB flash memory and 2kB SRAM 16mHz clock speed Provides USB connection 14 digital input and output pins 6 analog input pins Adafruit Bluefruit EZ Link Bluetooth Bluetooth serial link and Arduino programmer 10m range and 9600 Baud rate LabVIEW is a graphical user interface and instrument control tool used to acquire and analyze measurement data Professional engineering platform that allows access to any networked user. Allows remote activation Utilized to generate data plots LabVIEW Display Designed and created the following components using AutoDesk Inventor, and Stratsys and MakerBot Z18 3D Printers: Purchased and installed the following components: Easy On/Off Magnetic Switch (150lb pull strength) Zinc plated steel in-line ball joint linkage Steel Push Pins Mounting Assembly Magnetic L-mount Block Adapter Angle AdapterElectronics enclosure Configurations Assembly configurations allow for multiple mounting angles on ship hull 20lb force applied designated point of the L-shaped bracket ABS plastic construction Minimal deformation FE Analysis 40lb force applied at the end of a 24 inch aluminum 4043 hollow rod inch wall thickness Minimal deformation Multiple tests were performed to verify the device specifications: Blue Tooth Signal Range Temperature Waves Precipitation Testing Blue Tooth Signal Range: Blue tooth signal was successfully transmitted up to 33ft from a PC Temperature Range: The sonar system was operational between 32 76 F Wave Height Testing Wave Height (inches) Manual Draft Measurement (inches) Average value from sonar readings (inches) Difference (inches) Condition #1 Water spray was directed through the sonar beam inch waves were introduced Precipitation Testing Condition #2 Water spray was directed at the target zone. No waves were introduced Condition #1Condition #2 Manual Draft Measurement (inches) Average value from sonar readings (inches) Difference (inches) The following design specifications were met : 1/8 th inch accuracy: Desired accuracy was achieved in calm water conditions and in wave heights ranging between 2-8 inches. However, the system is not recommended in rain conditions. Economical: Rapid prototyping utilizing 3D printing reduced costs over traditional machine shop labor, and using readily available off the shelf components reduced hardware costs. Portable: Components are made of light weight ABS plastic and are modular, which allows easy assembly and transport. Wireless: Bluetooth technology provides sufficient range for testing the concept. Reduce risk to personnel: System will automate draft measurement process, eliminating the need for technicians to be in small crafts to manually take measurements. Non-permanent mounting: Using a magnetic mounting system, the device can be easily mounted and removed without damage to the carriers protective hull coating. Conclusions Gantt Chart Faculty Advisor Dr. Miltiadis Kotinis Shipyard Liaison Butch Brenton Manager Engineering 3 Department of Mechanical and Aerospace Eng. David Mooney Team Manager Sam Harpin David Mann Philip Stickle Devin Samples-Wright Thomas Wheeless Department of Electrical and Computer Eng. Ashley Smith Department of Engineering Tech. Ashley Wilson EET Additional Assistance: Dr. Navid Tahvildari Wave tank training Dr. Gangfeng Ma Wave tank training Michael Polanco 3D Printing and Poster Assistance Acknowledgements Questions?