Dangerous Driving Event Analysis System by a Cascaded Fuzzy Reasoning Petri Net

1. Dangerous Driving Event Analysis Systemby a Cascaded Fuzzy Reasoning Petri Net Chiung-Yao Fang Hsiu-Lin Hsueh Sei-Wang Chen National Taiwan Normal University Department of Computer Science and Information Engineering

2. Outline • Introduction • System flowchart • Cascaded fuzzy reasoning Petri net • Dangerous driving event analysis system • Experimental results • Conclusions and future work

3. Introduction • Driver assistance system • Passive methods • Active methods • Active driver assistance system • Detection component • Analysis component

4. … Sensor 1 Sensor 2 Sensor n Detection component Detection system 1 Detection system 2 … Detection system n Analysis component Dangerous driving event analysis system Warning output Block Diagram of an Active DAS

5. Start Data acquisition CFRPN Behavior analysis of our vehicle Interaction analysis between nearby vehicles and our vehicle Driving event integration Degree of danger computation Degree of danger output Flowchart of the Analysis System

6. Cascaded Fuzzy Reasoning Petri Net (CFRPN)

7. The Production Rules of FRPN • Rule 1: where : confidence vector of rule associated with the only corresponding transition • Rule 2: where : confidence vector of the rule related to the corresponding m transitions

8. Fuzzy Reasoning Algorithm

9. Some Terminology • Lateral distance • Forward distance Right- front vehicle Forward distance Our vehicle Lateral distance

10. Left- front vehicle Preceding vehicle Right- front vehicle Left vehicle Our vehicle Right vehicle Left- rear vehicle Following vehicle Right- rear vehicle Using FRPNs for Reasoning • An example • Get the membership values of • Lateral distance • Position • Speed • Input to the fuzzy reasoning Petri net • Speed change reasoning • Lane change reasoning • Integration

11. Membership Functions • Lateral distance • Position • Speed Lateral distance (m) Position (m) Speed (km/hr)

12. Example of Lane Change Reasoning • Vo : our vehicle • Vlf : left-front vehicle (1) : Vo moves without lane change. (2) : Vo changes to the left lane. (3) : Vo changes to the right lane. (4) : Vlf moves without changing lane. (5) : Vlf changes to the left lane. (6) : Vlf changes to the right lane. (7) : Vlf and Vo are moving in the same lane. (8) : Vlf and Vo are moving in different lanes.

13. Example of Lane Change Reasoning • Two production rules: • : occurrence possibility that “Vlf and Vo are moving in the same lane.” • : occurrence possibility that “Vlf and Vo are moving in different lanes.”

14. Corresponding FRPN • : left-front vehicle and our vehicle are moving in the same lane • : left-front vehicle and our vehicle are moving in different lanes

15. Example of Speed Change Reasoning • Vo : our vehicle • Vlf : left-front vehicle (1) : forward distance between Vlf and Vo is close (2) : speed of Vo is slower than that of Vlf (3) : speeds of Vlf and Vo are equal (4) : speed of Vo is faster than that of Vlf (5) : forward distance between Vlf and Vo increases (6) : forward distance between Vlf and Vo remains the same (7) : forward distance between Vlf and Vo decreases

16. Example of Speed Change Reasoning • Three production rules: • To decide the occurrence possibilities of the following driving events: • Forward distance between Vlf and Vo increases • Forward distance between Vlf and Vo decreases • Forward distance between Vlf and Vo remains unchanged

17. Corresponding FRPN • : forward distance between Vlf and Vo increases • : forward distance between Vlf and Vo remains the same • : forward distance between Vlf and Vo decreases

18. Integration • Integration rule: • : degree of danger of the interaction between Vlf and Vo

19. Part of CFRPN Road change reasoning Integration Speed change reasoning

20. Freeway Driving Event Simulation • Objective – provide experimental data • Two major stages: • Simulation of freeway environments • Simulation of vehicle behaviors

21. Simulation of Freeway Environments • Given: • Total length of the freeway • Number of toll stations, tunnels, freeway entries and exits • Produce: • Total lengths of tunnels • Locations of toll stations, tunnel entries and exits, freeway entries and exits • Locations of road signs

22. Left- front vehicle Preceding vehicle Right- front vehicle Left vehicle Our vehicle Right vehicle Left- rear vehicle Following vehicle Right- rear vehicle Simulation of Vehicle Behaviors • Given : • Vehicle positions and moving directions (of our vehicle and nearby vehicles) • Produce : • Vehicle speed • Lateral distance • Directional signal • Braking signal

23. Experimental Results • Conditions: • Our vehicle moves without lane change. • The left-front vehicle changes its lane to the right. • The speed of our vehicle is faster than that of the left-front one.

24. Experimental Results Our vehicle moves without changing lane 0.731 Left-front vehicle and our vehicle are moving in the same lane 0.227 0.022 0.731 0.131 0.131 Left-front vehicle changes lane to the right 0.015 0.002 0.724 0.802 0.000 Dangerous 0.047 0.953 0.002 Our vehicle is faster than the left- front one 0.000 Distance between left-front vehicle and our vehicle decreases 0.971

25. Degrees of Danger of Interactions Between Left-front Vehicle Vlf and Our Vehicle Vo

26. Degrees of Danger of Interactions Between Preceding Vehicle Va and Our Vehicle Vo

27. Conclusions and Future Work • Dangerous driving event analysis system • Reasoning by a cascaded FRPN module • Detection subsystem integration • Warning drivers • Future work: integrate into the driver assistance system • Freeway driving event simulation system • Provide experimental data • Support other driver assistance subsystems • Future work: include more road conditions