ChiungYao Fang

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
Block Diagram of an Active DAS
5
Flowchart of the Analysis System
6
Cascaded Fuzzy Reasoning Petri Net (CFRPN)
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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
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Some Terminology

• Lateral distance
• Forward distance

Right- front vehicle
Forward distance
Our vehicle
Lateral distance
10
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.

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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.

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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

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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

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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

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Integration

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

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Part of CFRPN
Road change reasoning
Integration
Speed change reasoning
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Freeway Driving Event Simulation

• Objective provide experimental data
• Two major stages
• Simulation of freeway environments
• Simulation of vehicle behaviors

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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

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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

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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.

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Experimental Results
0.731
Left-front vehicle and our vehicle are moving in
the same lane
Our vehicle moves without changing lane
0.227
0.731
0.022
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
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Degrees of Danger of Interactions Between
Left-front Vehicle Vlf and Our Vehicle Vo
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Degrees of Danger of Interactions Between
Preceding Vehicle Va and Our Vehicle Vo
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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