1. Electrical and Computer Engineering 05/03/07 Accident Warning System at Intersection Richa Prasad ● Raza Kanjee ● Hui Zhu ● Thai Nguyen Professor Prishro-Nik Advisor, Assistant Professor, ECE Professor Ni Advisor, Assistant Professor, CEE Team Pishro-Nik & Ni

2. 2 Electrical and Computer Engineering 05/03/07 Content Introduction The Design Deliverables System Block Diagram Design Alternatives Product Cost Power Specifications Checklist

3. 3 Electrical and Computer Engineering 05/03/07 Content Checklist 1 – Traffic Light Checklist 2 – Transceiver Communication Checklist 3 – Theoretical Latency Calculations Checklist 4a – GPS-Laptop Communication Checklist 4b – GPS data reception by RSU Laptop Checklist 5 – RSU Algorithm Checklist 6 – Testing and Debugging Statistical Analysis Conclusion

4. 4 Electrical and Computer Engineering 05/03/07 Introduction These situations at intersections represent about: 65% of injury accidents 70% of fatal accidents Annual fatality rate > 40,000 for more than 30 years © PReVENT Straight Crossing: 203,000 PAR crashes 200,000 non-PAR crashes Injury, casualty, traffic delay, economic loss

5. 5 Electrical and Computer Engineering 05/03/07 The Design VII DSRC Vehicle Infrastructure Integration Entertainment Safety Traffic Routing Weather Tutor Dedicated Short Range Communication 5.9 GHz Frequency Band Allocated for VII IEEE Standard: 802.11p Path Suggestion Speed Suggestion Pedestrian Warning Traffic Management © PReVENT

6. 6 Electrical and Computer Engineering 05/03/07 Deliverables RSU is warned of traffic light turning red Message sent to red car asking for speed and position OBU sends back speed and location RSU calculates whether red car will run red light If yes, blue car warned 1 2 3 4 GOALS Real-life demonstration Running light warning only Simulation of two cars – one moving, one at light Technical Documentation © PReVENT

7. 7 Electrical and Computer Engineering 05/03/07 System Block Diagram

8. 8 Electrical and Computer Engineering 05/03/07 Design Alternatives Laser Sensors Video Camera RFID Detection Speed Gun OnBoard Diagnostic GPS Alternatives Beyond Scope Not accurate No location Too expensive Does not provide location Microcontroller Laptop Alternative Expansion of Project DSRC Transceiver Transceiver Alternative Not available

9. 9 Electrical and Computer Engineering 05/03/07 Product Cost

10. 10 Electrical and Computer Engineering 05/03/07 Power Specifications USB Cable USB provides 5 VDC Powers: - GPS - Airbornedirect Bridge Laptop – self-powered Wireless Access Point – 12 VDC Solution – 12 V Battery Pack

11. 11 Electrical and Computer Engineering 05/03/07 Checklist 1.Traffic Light 2.Transceiver Communication 3.Latency Calculations 4.GPS-Laptop Communication 5.GPS data reception by RSU 6.RSU Algorithm 7.Testing and Debugging

12. 12 Electrical and Computer Engineering 05/03/07 Checklist 1 – Traffic Light SPECIFICATIONS SV Car B SV DczDilemma Zone DstopW L Dilemma Zone Subject Vehicle cannot cross safely before red light Subject Vehicle cannot stop safely at stop line Aim Reduce Dilemma Zone Gazis et. Al: Posted Speed Limit tamber 5 s

13. 13 Electrical and Computer Engineering 05/03/07 Checklist 1 – Traffic Light 85 s 5 s 90 s Timeline Virtual Simulation …………………………GPS Data………………………Traffic Light StateTraffic Light Time C++ Data Array G G R 2 1 90 To: GPS Data Received GPS Data updated every second Add last 2 cells with Traffic Light Data

14. 14 Electrical and Computer Engineering 05/03/07 Checklist 2 – Transceiver Communication SPECIFICATIONS Airbornedirect Serial Bridge RS232 Serial Communication 802.11b/g Compliant 5 VDC External Supply CONNECTIVITY 12 VDC Ethernet 5 VDC Serial RSUOBU Access Point Bridge 802.11g

15. 15 Electrical and Computer Engineering 05/03/07 Checklist 2 – Transceiver Communication RSU Transceiver IP Address RSU Transceiver Setup

16. 16 Electrical and Computer Engineering 05/03/07 Checklist 2 – Transceiver Communication OBU Transceiver Setup Setup Connection Speed between OBU Transceiver and OBU Laptop

17. 17 Electrical and Computer Engineering 05/03/07 Checklist 2 – Transceiver Communication OUTPUT OBU RSU

18. 18 Electrical and Computer Engineering 05/03/07 Checklist 3 – Theoretical Latency Calculations MODEL SCENARIO Car approaching intersection Car waiting at intersection If red car running light; both cars warned Aim: Speeding Car – Emergency Braking Other cars warned; caution Signalized Intersection, Straight Crossing Path (SI/SCP)

19. 19 Electrical and Computer Engineering 05/03/07 Checklist 3 – Theoretical Latency Calculations BACKGROUND OF ACCIDENTS Snowy or Icy 2% Wet Pavement 19% Dry 79% No Adverse Weather 66% Rain 12% Snow/Sleet 12% Daylight 72% Dark, Lighted 22% Dark, Unlighted 3% Dawn/Dusk 3% Travel Velocity (mph) SI/SCP Crash Occurrence due to Pavement Condition SI/SCP Crash Occurrence due to Ambient Weather Condition SI/SCP Crash Occurrence due to Ambient Light Condition Driver Inattention 36.4% Failed to Obey Signal 23.2% Tried to beat Signal 16.2% Driver Intoxication 12.9% Other 5.9% Vision Obstructed 4.3% Vehicle Defect 1.9%

20. 20 Electrical and Computer Engineering 05/03/07 Checklist 3 – Theoretical Latency Calculations WARNING SYSTEM Green Light? Start Amber Light? Red Light? Car can clear? Warning No Action No Yes Factors Travel Speed Duration of amber light Level of braking Driver + machine delays

21. 21 Electrical and Computer Engineering 05/03/07 Checklist 3 – Theoretical Latency Calculations ROAD CALCULATIONS SV Car B SV DczDilemma Zone DstopW L Dcz = Clearance Zone Car can cross easily. Safe passing guaranteed Dilemma Zone Car can’t stop on time; can’t cross safely Dstop Distance required to come to a stop L = length of car W = width of intersection SV = Subject Vehicle Vsv = Velocity of Subject Vehicle a = deceleration rate trm + tmd = time delay due to human + machine Distance traveled in time left before red light Length of Car Width of Intersection Dcz = -- Distance for car to stop Human + Machine Delay Dstop = +

22. 22 Electrical and Computer Engineering 05/03/07 Checklist 3 – Theoretical Latency Calculations ROAD CALCULATIONS Speed (kph) Dcz (m) Dcz at different speeds with different amounts of time left before red light

23. 23 Electrical and Computer Engineering 05/03/07 Checklist 3 – Theoretical Latency Calculations ROAD CALCULATIONS In Dcz? a = + or 0? Calculate deceleration for v =0 at stop line Comfortable range? Time to reach stop line Calculate Dstop Dstop < Dloc Warning ts < tg Start ts = time to reach stop line tg = time for light to turn green Dloc = distance from stop line Yes No Yes No

24. 24 Electrical and Computer Engineering 05/03/07 SYSTEM LATENCIES Traffic Light Laptop Transceiver GPS Laptop Transceiver RSURSU OBUOBU Almost Immediate 2400 baud = 19200 bps Longitude + Latitude + Speed Info + Connection + Time = 47 bytes = 376 bits Human + Machine Delay = 2.0s Comfortable deceleration = 0 to 3 m/s 2 1. Status Messages: RSU Laptop logs and saves data 2. Event Messages: RSU performs calculations 3. Status Messages: ALL calculations and data saved Checklist 3 – Theoretical Latency Calculations GPS Update = every 1.0s Size sent = 376 bps Available versus Used = 51:1

25. 25 Electrical and Computer Engineering 05/03/07 Checklist 4a – GPS-Laptop Communication 1.Read GPS Data 2.Extract Time, Connection, Longitude, Latitude, Speed 3. Transmit data to RSU

26. 26 Electrical and Computer Engineering 05/03/07 Checklist 4b – GPS Data Reception by RSU RSU Road Calculation Flowchart Implementation

27. 27 Electrical and Computer Engineering 05/03/07 Checklist 5 – RSU Algorithm Implementation of Road Calculation Algorithm Gets GPS + Traffic Light data Calculates distance from OBU Checks if car is decelerating or accelerating or cruising If decelerating, checks if distance needed to stop < actual distance from RSU If accelerating, checks if needed deceleration to stop in comfortable range Calculates time left to cross stop line versus time left for light to turn/remain green Starts the audio alarm + sends alarm to OBU Controls branching of ‘flowchart’ Starts program by setting traffic light countdown

28. 28 Electrical and Computer Engineering 05/03/07 Checklist 6 – Testing and Debugging LocationSetup RSU OBU System

29. 29 Electrical and Computer Engineering 05/03/07 Checklist 6 – Test 1 – Clearance Zone In Dcz? Start Yes Distance can travel before traffic light changes Length of Car Width of Intersection Currently Red: Want Car to be outside Clearance Zone Current Green: Want Car to be within Clearance Zone Field Test Data Speed (m/s)Traffic Light (s)To…Distance (m)Clearance Zone Distance (m)Alarm 13.5528 15.497 17.062 18.574 19.546 45 43 41 39 37 R R R R R 591.08 647.529 680.93 705.57 704.386 118.992 89.761 57.571 24.42 14.44 0 0 0 0 0

30. 30 Electrical and Computer Engineering 05/03/07 Checklist 6 – Test 2 – Acceleration In Dcz? a = + or 0? Calculate deceleration for v =0 at stop line Comfortable range? Time to reach stop line Warning ts < tg Start Yes No Yes Field Test Data Speed (m/s) Traffic Light (s) ToDistance (m)Clearance (m)Alarm 15.335 17.062 18.0885 18.790 19.222 2 25 23 21 19 R G G G G 11.839 407.735 397.206 375.770 346.396 190.554 158.786 124.882 89.304 53.327 0 1 1 1 Time Stop (s) 19.384 19.546 17 15 G G 16.587 20.547 310.705 274.366 Predict acc (m/s2) -0.617 -0.916 -1.31 -1.97 -3.464 -11.327 -9.296 2.883 0.863 1.062 0 0 0

31. 31 Electrical and Computer Engineering 05/03/07 Checklist 6 – Test 3 – Deceleration In Dcz? a = + or 0? Time to reach stop line Calculate Dstop Dstop < Dloc Warning ts < tg Start Yes No Yes No Field Test Data 17.8185 16.766 14.146 11.4471 8.96326 35 33 31 29 27 G G G G G 604.8186 528.199 419.722 313.135 223.178 107.641 75.030 46.65 23.342 8.936 0 1 1 1 1 6.137 4.512 2.602 0.613 Speed (m/s) Traffic Light (s) ToDistance (m)Clearance (m)Time Stop (s)Predict acc (m/s2)Alarm -1.475

32. 32 Electrical and Computer Engineering 05/03/07 Checklist 6 – Test 4 – Stop, Start ROAD CALCULATIONS In Dcz? a = + or 0? Calculate deceleration for v =0 at stop line Comfortable range? Time to reach stop line Calculate Dstop Dstop < Dloc Warning ts < tg Start ts = time to reach stop line tg = time for light to turn green Dloc = distance from stop line Yes No Yes No

33. 33 Electrical and Computer Engineering 05/03/07 Checklist 6 – Test 4 – Stop, Start Field Test Data

34. 34 Electrical and Computer Engineering 05/03/07 Statistical Analysis Confidence of False Alarm

35. 35 Electrical and Computer Engineering 05/03/07 Statistical Analysis Frequency of Alarm with Distance

36. 36 Electrical and Computer Engineering 05/03/07 Statistical Analysis GPS Inaccuracy 91 Count 8.603013178.79788284.183348Range 0.374785-72.53424842.377743Minimum 4.977798-72.53406942.377827Maximum -0.360205-0.0528060.085105Skewness 1.3358230.000000 Variance 1.1557780.0000440.000021Std Dev 4.064632-72.53415342.377785Mode 3.177549-72.53415842.377784Median 0.1042360.2371420.223746Std Error 3.082612-72.53415842.377787Mean DistanceWestingsNorthings

37. 37 Electrical and Computer Engineering 05/03/07 Statistical Analysis GPS Inaccuracy

38. 38 Electrical and Computer Engineering 05/03/07 Statistical Analysis Confidence of Connection

39. 39 Electrical and Computer Engineering 05/03/07 Conclusion 1.Traffic Light 2.Transceiver Communication 3.Latency Calculations 4.GPS-Laptop Communication 5.GPS data reception by RSU 6.RSU Algorithm 7.Testing and Debugging