1. Direction-Finding Sonar System for Autonomous Submarine Estee Amana, Nicole Rennalls, Mitcham Costley, Frederick Ealick ECE Department Georgia Institute of Technology ECE4007 L01 October 22, 2008

2. Project Overview

3. Submarine

4. Autonomous Underwater Vehicle

5. Georgia Tech Marine Robotics Group

6. Navy SEAL Practice Pool

7. Navy Competition 2009 Launch Platform Practice Side Competition Side Bridge Rooftop

8. Mission To build sonar system under $400 to complete “Rooftop” task for competition

9. Design Objectives

10. Detect Ping Frequency: 20-30kHz 2s 1.3ms

11. 60° Determine Direction Top View Direction of Motion

12. MRG Group Sonar Group RS-232 Communication

13. Physical Constraints Length5” Width5” Depth2” Voltage24VDC Current2A

14. t1 t2 t1< t2 Time Delay Receiver #1 Receiver #2

15. Technical Approach

16. Sonar System Block Diagram Hydrophones Pinger Variable Gain Amplifier ADC Measure Time Delay RS232RS232 Linux SBC

17. Hydrophones Pinger Variable Gain Amplifier ADC RS232RS232 Linux SBC Measure Time Delay

18. Hydrophone Construction Transducer Metal Casing Metallic Membrane Coaxial Cable Cost: $150

19. Amplifiers Hydrophones Pinger Variable Gain Amplifier ADC RS232RS232 Linux SBC Measure Time Delay

20. Filtering Amplifier Design and Testing Four stage amplifier circuit Band pass filter to remove noise μVμV V Cost: $50

21. Amplification Incoming Hydrophone Signal Outgoing Amplified Signal

22. Linux SBC Hydrophones Pinger Variable Gain Amplifier ADC RS232RS232 Linux SBC Measure Time Delay

23. Sonar System Controller Receives 1000 samples/channel Averages 10 highest & 10 lowest samples Determines time delay Cost: $150

24. Cross-correlation V Time (sec) V2V2

25. Auto-calibration Goal: Eliminate error from submarine design changes, trace lengths, etc. Hydrophone Submarine Pinger Direction of motion

26. Demonstration Hydrophones Waterproof PVC Pipe Pinger GT Pool Laptop Serial Cable Electronics

27. Current Status Construct and test amplifier prototype Implement existing embedded code Build hydrophones Construct amplifier on solder board Test automatic gain control

28. Dec Project Schedule OctNov Test amplifier with pinger Control gain Demonstration Competition Date: June 2009 Mount hydrophones Assemble circuit solder board Complete hydrophones Integrate system Design PCB