Air Coupled Ultrasonic Imaging For Non-Destructive Testing



Download 11.4 Kb.
Date28.12.2016
Size11.4 Kb.

Air Coupled Ultrasonic Imaging For Non-Destructive Testing

  • GTL Ultrasonics
  • David Lavery
  • Andrew Ray
  • Mario Malave
  • Preliminary Design Review
  • March 10, 2009

Project Overview

  • Project Overview
  • Current State of the Project
  • Current Needs
  • Ongoing Development
  • Projected Schedule
  • Market Analysis
  • Future Considerations

Air Coupled Ultrasonics

Objectives

  • Develop a working ACU system using a novel transducer material
  • Reduce Cost
  • Increase Efficiency
  • Mobile System

A Novel Transducer Material

  • What?
    • Silver coated polymer-foam
    • High Quasi-Static piezoelectric coefficient
      • 25-700 pC/N
    • Low Acoustic Impedance
      • 0.028 MRayl

A Novel Transducer Material

  • Why?
    • High frequency transmission to air
    • Increased efficiency
    • Decreased cost

Current State of the Project

Current Needs

  • Material Characterization
  • Electromagnetic Noise
  • Supporting Circuitry Size
  • Housing Design

Ongoing Development

  • Transducer Optimization
    • Extend instability limits
    • Increase transducer efficiency
    • Increase piezoelectric coefficient
  • Size
  • Shape

Ongoing Development

  • Transducer Optimization

Ongoing Development

  • Transducer Characterization
    • How does the transducer behave in the presence of certain material characteristics
    • Based on acoustic pressure across transducer

Ongoing Development

  • Transducer Characterization
  • http://www.ukessays.com/essays/physics/cardiac-ultrasound-machine.php

Ongoing Development

  • Noise Reduction
    • Antenna
    • Logic circuit
    • Separation of signals

Antenna

  • Design a copper material which will border the transducer
  • Antenna shape will be determined by the transducer design
  • Electromagnetic energy (noise) is received for removal with a differential amplifier circuit

Logic circuit

  • Threshold detection
    • comparator circuit to detect presence of electromagnetic noise
  • Ensure noise has been removed

Separation of signals

  • Instrumentation amplifier that will remove the antenna data from the received signal
  • Bandpass filter the signal to reduce remaining noise
  • Amplify the remaining signal for processing
  • Transducer Signal Processing
  • Input Signal
  • Antenna Signal
  • -
  • Amplifier
  • Bandpass Filter
  • Image Signal Processing
  • (Matlab)

Ongoing Development

  • Circuitry
    • Filter
    • Amplifier
    • Logic Circuit

Circuitry

Differential Amplifier

  • Eliminates background noise
  • Eliminates electromagnetic noise

Differential Amplifier

Band Pass Filter

  • Limits signal to ultrasonic frequencies of interest
  • Easily configurable passband

Band Pass Filter

Output Amplifier

Filter Frequency Response

System Performance

  • Most electromagnetic noise suppressed
  • Signal amplified 40dB above input signal

Projected Schedule

  • Task
  • Progress
  • Start
  • End
  • Circuitry Design
  • In Progress
  • February 25th
  • March 13th
  • Transducer Characterization
  • In Progress
  • February 23rd
  • March 25th
  • Circuitry Fabrication
  • March 14th
  • March 19th
  • Transducer Housing
  • Not yet started
  • March 14th
  • March 22nd
  • Signal Analysis
  • Not yet started
  • March 26th
  • April 10th
  • Final System Integration
  • Not yet started
  • April 7th
  • April 12th

Market Analysis

  • Frequently used couplants used for transmission
    • Oil, glycerin, and water
    • Success with air can open a new market of devices
  • Possible Device Users
    • Aviation/Aerospace companies; Boeing, Lockheed Martin, NASA
  • NASA Space Shuttle
    • Currently uses Laser Dynamic Range Imager (LDRI)
      • Only provides superficial data
      • Air Coupled Ultrasonics (ACU) provides information deeper than the surface

Updated Parts Cost Table

  • Part Description
  • Quantity
  • Unit Price
  • Price
  • 2'x2' Printed Circuit Board (PCB)
  • 2
  • $3.45
  • $6.90
  • Operational Amplifiers (Op-amp)
  • 10
  • $1.50
  • $15.00
  • Resistor
  • 10
  • $0.90
  • $9.00
  • Capacitor
  • 5
  • $0.95
  • $4.75
  • BNC Connectors
  • 4
  • $5.00
  • $20.00
  • Custom Machined Aluminum
  • 2
  • $30.00
  • $60.00
  • Cellular Polypropylene Foam (1m)
  • 1
  • $15.00
  • $15.00
  • DC Power Supply (400 W)
  • 1
  • $100.00
  • $100.00
  • Cable (10 ft BNC)
  • 1
  • $20.00
  • $20.00
  • Mounting Hardware Kit
  • 1
  • $20.00
  • $20.00
  • Project Total
  •  
  •  
  • $270.65

Cost Analysis

  • 60 Engineering hour for each group member
    • $50/hr give a cost of $9000 in labor
  • 22.8% profit at a sales price of 2,500 ($571 per unit sold)

Future Issues

  • Developing supporting software
  • User interface design


Download 11.4 Kb.

Share with your friends:




The database is protected by copyright ©sckool.org 2020
send message

    Main page