120706 DSRC Accident Warning System at Intersection Team

12/07/06 DSRC Accident Warning System at Intersection Team Pishro-Nik & Ni Richa Prasad ● Raza Kanjee ● Hui Zhu ● Thai Nguyen Professor Prishro-Nik Advisor, Assistant Professor, ECE Electrical and Computer Engineering Professor Ni Advisor, Assistant Professor, CEE

12/07/06 Content • Introduction • The Design • Deliverables • System Block Diagram • MDR Specifications • Spec 1 – Latency Calculations • Spec 2 – Transceiver • Spec 3 – Traffic Light • Power Specifications • Product Cost • PDR I Questions • Summary Electrical and Computer Engineering 2

12/07/06 © PRe. VENT 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 Electrical and Computer Engineering Straight Crossing: • 203, 000 PAR crashes • 200, 000 non-PAR crashes • Injury, casualty, traffic delay, economic loss 3

12/07/06 The Design VII • Vehicle Infrastructure Integration Tutor Entertainment Safety DSRC Traffic Routing Weather • Dedicated Short Range Communication • 5. 9 GHz Frequency Band • Allocated for VII • IEEE Standard: 802. 11 p Traffic Management Speed Suggestion Pedestrian Warning © PRe. VENT Path Suggestion Electrical and Computer Engineering 4

12/07/06 Deliverables 1 2 OBU sends back speed and location RSU is warned of traffic light turning red 3 RSU calculates whether red car will run red light Message sent to red car asking for speed and position If yes, blue car warned 4 GOALS • Real-life demonstration • Running light warning only • Simulation of two cars – one moving, one at light • Technical Documentation © PRe. VENT Electrical and Computer Engineering © PRe. VENT 5

12/07/06 System Block Diagram Electrical and Computer Engineering 6

12/07/06 System Block Diagram Not Complete Electrical and Computer Engineering 7

12/07/06 MDR Specifications AIM Latency Calculations • Distance for Vehicle Warning • Determination of car running red light • Background for Accident Conditions • Wireless connection between Bridge & AP Transceiver • Two-way communication between laptops • Data communicated = random && != GPS • Hardware Simulation of traffic light Traffic Light • Display of changing conditions on Bar LED • Changing conditions recognized by laptop Electrical and Computer Engineering 8

12/07/06 Spec 1 – Latency Calculations MODEL SCENARIO Aim: • Speeding Car – Emergency Braking • Other cars warned; caution Car approaching intersection Car waiting at intersection Signalized Intersection, Straight Crossing Path (SI/SCP) Electrical and Computer Engineering If red car running light; both cars warned 9

12/07/06 Spec 1 - Latency Calculations BACKGROUND OF ACCIDENTS SI/SCP Crash Occurrence due to Pavement Condition SI/SCP Crash Occurrence due to Ambient Weather Condition Rain 12% Snowy or Icy 2% Dry 79% Wet Pavement 19% Snow/Sleet 12% SI/SCP Crash Occurrence due to Ambient Light Condition Dark, Unlighted 3% Dark, Lighted 22% No Adverse Weather 66% SI/SCP Crash Occurrence Vision Obstructed 4. 3% Other 5. 9% Driver Intoxication 12. 9% Dawn/Dusk 3% Daylight 72% Vehicle Defect 1. 9% Driver Inattention 36. 4% Failed to Obey Signal 23. 2% Tried to beat Signal 16. 2% Travel Velocity (mph) Electrical and Computer Engineering 10

12/07/06 Spec 1 – Latency Calculations WARNING SYSTEM Factors Start Green Light? Yes • Travel Speed No Action • Duration of amber light • Level of braking Yes No Amber Light? Yes No No Red Light? Electrical and Computer Engineering • Driver + machine delays Car can clear? No Yes Warning 11

12/07/06 Spec 1 - Latency Calculations ROAD CALCULATIONS L SV Dilemma Zone Dcz Dstop • 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 Electrical and Computer Engineering Car B SV W Distance traveled Length of - Width of Dcz = in time left before Car Intersection red light Dstop = Distance for car to stop + Human + Machine Delay 12

12/07/06 Spec 1 - Latency Calculations ROAD CALCULATIONS Dcz (m) Dcz at different speeds with different amounts of time left before red light Speed (kph) Electrical and Computer Engineering 13

12/07/06 Spec 1 - Latency Calculations ROAD CALCULATIONS In Dcz? 30 s to Red ts = time to reach stop line tg = time for light to turn green Yes No No Calculate Dstop Yes Dstop < Dloc a = + or 0? Yes Calculate deceleration for v =0 at stop line No No Action Yes Comfortable range? Warning Time to reach stop line Yes ts < tg No No Dloc = distance from stop line Electrical and Computer Engineering 14

12/07/06 Spec 1 - Latency Calculations SYSTEM LATENCIES Traffic Light R GPS Almost Immediate Laptop U O B Laptop Almost Immediate U Almost Immediate Transceiver • 2400 baud = 19200 bps • Human + Machine Delay = 2. 0 s • Longitude + Latitude + Speed Info = 12 bytes = 96 bits • Comfortable deceleration = 0 to 3 m/s 2 • GPS Update = every 0. 5 s • Size sent = 192 bps • Status Messages: > 30 s for red light • Available versus Used = 100: 1 • Event Messages: < 30 s for red light 1. Status Messages: RSU Laptop logs and saves data 2. Event Messages: RSU performs calculations Electrical and Computer Engineering 3. Status Messages: ALL calculations and data saved 15

12/07/06 Spec 2 - Transceiver SPECIFICATIONS • Airbornedirect Serial Bridge • RS 232 Serial Communication • 802. 11 b/g Compliant • 5 VDC External Supply Bridge 12 VDC 5 VDC 802. 11 g Ethernet Serial Access Point RSU Electrical and Computer Engineering CONNECTIVITY OBU 16

12/07/06 Spec 2 - Transceiver OUTPUT RSU OBU Video Available on Request! Electrical and Computer Engineering 17

12/07/06 Spec 3 – Traffic Light SET UP Powered by USB Bar LED Traffic Light External Clock Power is on Maxim chip – TTL to RS 232 and vice versa • Green to Warning – 60 s Microprocessor programmed with traffic light code JTAG programmer • Warning to Yellow – 25 s • Yellow to Red – 5 s • Green to Red – 90 s Indicator of data transfer Warning – 30 s Electrical and Computer Engineering 18

12/07/06 Spec 3 – Traffic Light SPECIFICATIONS L SV Dilemma Zone Car B SV Dcz Dstop W Dilemma Zone • Subject Vehicle cannot stop safely at stop line Aim tamber • Subject Vehicle cannot cross safely before red light 5 s • Reduce Dilemma Zone Gazis et. Al: Posted Speed Limit Electrical and Computer Engineering 19

12/07/06 Spec 3 – Traffic Light SCHEMATIC Electrical and Computer Engineering 20

12/07/06 Spec 3 – Traffic Light OUTPUT Warning sent 30 s before light turns red Video Available on Request! Electrical and Computer Engineering 21

12/07/06 Power Specifications • Wireless Access Point – 12 VDC • Solution – 5 V to 12 V Booster Circuit USB Cable • USB provides 5 VDC Powers: - GPS - Airbornedirect Bridge - Traffic Light • Laptop – self-powered Electrical and Computer Engineering 22

12/07/06 Product Cost Electrical and Computer Engineering 23

12/07/06 PDR I Questions 1. We can adjust the traffic light to prevent collisions. So why do we need the system? • System too dynamic, unreliable. • Predictability of traffic lights lost 2. Elevation on highway. How check if signal received by RSU is from OBU on same highway at which RSU is located? • GPS provides altitude data • If RSU altitude != OBU altitude; ignore signal 3. Losing connection with GPS. Solution? • OBD II Implementation • DGPS prevents full loss of connection with GPS 4. Urban setting – Accuracy and loss of connection with GPS • OBD II Implementation • Video cameras, laser sensors Electrical and Computer Engineering 24

12/07/06 PDR I Questions 5. Plan for testing equipment? • Step 1 – Test in Lab • Step 3 – Record all data in field • Step 2 – Test in field • Step 4 – Debug and test further in lab 6. Performance of project under different road and weather conditions? • Specification 1 – Latency Calculations • Majority of accidents – normal conditions 7. Theoretical Latency Measurements? • Specification 1 – Latency Calculations 8. Vehicle not on road approaching intersection? • Specify road width • If collision predicted, should warn regardless Electrical and Computer Engineering 25

12/07/06 Summary CHECKLIST 1. Traffic Light 2. Transceiver Communication 3. Latency Calculations 4. a. GPS-Laptop Communication 5. b. GPS data reception by RSU Laptop 6. 5. RSU Laptop Road Calculation Algorithm 1 Latency Calculations 2 Transceiver 3 Traffic Light MDR SPECIFICATIONS Electrical and Computer Engineering 26