1. Wireless Localization System Using Propagation Timing Brian Dake Brian Vaughan Sean Brennan

2. Basics Localization using propagation timing Localization using propagation timing Location tracked in real time Location tracked in real time Can be used to control servos for tracking Can be used to control servos for tracking Spotlights, cameras, laser pointer, etc Spotlights, cameras, laser pointer, etc

3. Function 1 mobile mote 1 mobile mote 3 stationary motes 3 stationary motes Mote communication established through radio frequencies Mote communication established through radio frequencies Localization calculated using propagation delay of ultrasound wave Localization calculated using propagation delay of ultrasound wave Servo motors follow the mobile mote in real time Servo motors follow the mobile mote in real time

4. Design Motes from Crossbow Motes from Crossbow

5. Design Ultrasound TX/RX added to motes Ultrasound TX/RX added to motes Mobile mote incorporates ultrasound TX Mobile mote incorporates ultrasound TX Stationary mote incorporates ultrasound RX Stationary mote incorporates ultrasound RX TinyOS from Berkeley available online to program motes TinyOS from Berkeley available online to program motes

6. Implementation Mobile mote sends out radio and ultrasound signals at the same time Mobile mote sends out radio and ultrasound signals at the same time Mobile Mote Stationary Mote

7. Implementation Stationary mote measures time difference between radio and ultrasound pulse Stationary mote measures time difference between radio and ultrasound pulse Distance is calculated Distance is calculated Position is found using multiple stationary motes Position is found using multiple stationary motes Instructions given to servos for movement based on real time position Instructions given to servos for movement based on real time position

8. Problems Integrating ultrasound devices Integrating ultrasound devices –We can build our own motes using circuit diagrams from the MIT Cricket project –Just use radio strength data (less accurate) Time delay in processing location Time delay in processing location Might be easier to implement using UHF RFID Radar Might be easier to implement using UHF RFID Radar

9. Mini-Project Implement the mote system using two motes Implement the mote system using two motes Ultrasound and radio communication working Ultrasound and radio communication working

10. Questions?