Develop Eco-Driving Assistance Systems --- Value of Traffic Signal Status Information Dr. Guoyuan Wu Oct. 13 th, 2011
Outline Introduction and Motivation Eco-Driving Assistance Systems (EDAS) Using Traffic Signal Status (TSS) Information Roadside Infrastructure Based EDAS In-vehicle Device Based EDAS Simulation Test and Preliminary Results Conclusion and Future Work
Introduction (I) Automobile powered by fossil fuels are one of the major contributors to the greenhouse gas (GHG), e.g. CO 2, emissions GHG Emissions by Sources and Transportation Modes (2005) a a. ICF International Based on U.S. EPA's Inventory of U.S. Greenhouse Gas Emissions and Sinks
Introduction (II) How to increase energy efficiency and reduce emissions from cars? Improve vehicle manufacturing Lighter but stronger material More energy efficient vehicles Powered by other energy sources Apply intelligent transportation systems (ITS) Advanced traveler information systems e.g. VMS and eco-navigation Adaptive traffic signal control What else?
Eco-driving!!! Introduction (III) Smarter and more fuel-efficient driving Makes best use of advanced technologies Hints for being an eco-driver Anticipate traffic flow Maintain a steady speed at low RPM Use accessories more wisely For more hints, please visit http://www.ecodrive.org Always easier said than done
Motivation (I) Observation Unnecessary acceleration/hard braking in response to sudden changes of traffic signals Waste of energy Unsafe maneuver Why? Lack of traffic signal status (TSS) information What can we do? Provide real-time traffic signal status Predict when phase will change
Fuel Consumption (g) Does this idea work? Motivation (II) Construct hypothetic trajectories Apply Comprehensive Modal Emission Model (CMEM) Compare cases with and without TSS information Distance 20 15 16 16.2 16.7 Intersection j Vehicle i trajectory in case 1 Vehicle i trajectory in case 2 10 5 10.9 10.1 9.9 No TSS With TSS d j i (t) v i (t) t Time Results are promising! 0 35 mph 37 mph 40 mph Roadway Speed Limit
Eco-Driving Assistance System (EDAS) Concept Employ advanced detection, communication and data processing systems Assist driver to avoid unnecessary acceleration/deceleration Eco-Driving Assistance System Potential Type Roadside infrastructure In-vehicle device
System Architecture Input Model Output Real-time TSS Intelligent Decision Maker Assistance Advice Real-time Subject Vehicle Activity Other Traffic Information Arrival Time Predictor
Pros Easy to implement Cost effective VMS-Based EDAS Cons Not customized Less reliable Hard to extend
Pros In-Vehicle EDAS Customized More reliable Open for further integration Cons Complicated to design Higher cost
Network Setup Two signals Two-phased Fixed timing One vehicle type Other geometry settings Scenario Setup VMS-based Simulation Network Mounting distance varies with speed limit (200 meters for 40 mph) Fixed legibility distance --- 100 meters In-vehicle based Communication range --- 300 meters 100% penetration rate
Fuel Reduction (%) CO2 Reduction (%) Preliminary Results Fuel consumption and CO2 Emission Within 300 meters before signals Different congestion levels 14 12 12 10 10 8 6 4 VMS-based In-vehicle 8 6 4 VMS-based In-vehicle 2 2 0 0.25 0.5 0.6 0.7 0.8 0.85 v/c Ratio (Congestion Level) 0 0.25 0.5 0.6 0.7 0.8 0.85 v/c Ratio (Congestion Level)
Conclusion and Future Work Conclusion Develop two eco-driving assistance systems: VMS-based and in-vehicle Preliminary simulation tests show promising results on these two EADS In-vehicle EADS outperforms VMS-based in both fuel economy and CO2 emission reduction Benefit of EADS may vary with different traffic congestion level and roadway speed limit Future Steps More realistic network evaluation More sophisticated system incorporated other traffic information
Thank you & Questions