VIGILANT: Smart Phone Navigation for Visually Impaired Pedestrians

1. VIGILANT: Smart Phone Navigation for Visually Impaired Pedestrians Name: Affiliation: Anani Afanou ECE 4007 L02 Arpan Ghosh Daniel Newsome Date: Ken Orji April 15, 2009

2. Overview WHAT? Pedestrian “turn-by-turn” navigation using a Google G1 mobile phone WHO/WHY? Current navigation solutions for the visually impaired are cumbersome and expensive

3. Design Approach • DGPS Base Station • Accepts connections and transmits corrections values over LAWN • G1 Smart Phone • Connects to DGPS server and receives corrections (WLAN) • Send corrections to receiver and gets back corrected user position (Bluetooth) • GPS Receiver (with user) • Calculates user’s position from satellite(s) • Applies DGPS corrections to calculated position

4. Calculating Correction of Satellite Calculating User Position from Satellite DGPS Corrections User Position with Noise Removed <= DGPS Corr. => User Position User Position from Receiver Kalman Filter

5. Calculating Correction of Satellite Calculating User Position from Satellite DGPS Corrections User Position with Noise Removed <= DGPS Corr. => User Position User Position from Receiver Kalman Filter

6. Changes to Approach • Laptop will be used as communication intermediary • Laptop gets corrections • Laptop sends them to GPS receiver • Laptop gets corrected lat, long values • Forwards these to G1 phone. • Android Bluetooth API not ready • Code needs to be open sourced

7. Goals Supply user-friendly interface Audio feedback Receive differential GPS corrections Remove noise using Kalman filtering Provide dynamic turn by turn instructions Achieve accuracy < 2 Meters

8. Additional Features Route recalculation in case of user error Wrong turn, missed turn Goes off path User orientation at start Which direction to turn Wireless feedback (In progress)‏ Voice over hands-free Bluetooth headphones

9. Simple User Interface Voice feedback for each destination Keyboard support for quicker access

10. Dynamic Turn by Turn Navigation 100 ft 0.1 mi 0.4 mi 0.3 mi

11. Kalman Filtering Possible to achieve an accuracy of under 2 meters

12. Route Correction Wrong turn or missed turn Path deviation Provide new set of directions to get back on original path. Provide warnings to get back on track.

13. Directional Orientation ? • Obtain user’s heading in degrees • Calculate difference between current heading and desired heading • Prompt user to turn right, left or around accordingly.

14. Problems and Changes Currently no API for Bluetooth on Android - Laptop needed as a communication intermediary in prototype. - Send position updates to phone over wireless instead Running Kalman filter on laptop vs. G1 - C vs. Java - Gain in speed

15. Revised Budget / Cost Analysis • Android’s GPS API isn’t robust enough (yet) to apply corrections on its own GPS position estimates. • External GPS receiver required. • Marketing: • VIGILANT system will be sold, as software package, for a monthly fee of $49.99. • One time cost of receiver. • Remains a cheaper alternative to competitors like the Sendero GPS system (priced at $1,649).

16. Remaining Tasks Integration of code running on laptop with our application on the G1. SSH over wireless ad hoc network Testing! Testing! Testing!

17. Possible Future Work Add extra way points during runtime to visit on way to destination. Add extra parameters to Kalman filter to make it more accurate (e.g. acceleration, velocity)

18. Questions ?