Programmable Traffic Light Control Presented by ACE

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Intelligent Programmable
Traffic Light Controller
Project Proposal
Presented by
Maung Aung Naing Maung Nay M Aung Than Khar Chin
ECE 111
University of California, San Diego

Spring 2005
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Objective

• Design a traffic light controller which will be
  used at any type of 4-way intersections.

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Goal

• Intelligent system
• Sensor oriented system
• Every state can go to any state
• Adaptable depending on traffic flow
• Minimize travel time and traffic congestion
• Programmable system
• Programmable rush hour (max 2 sets)
• Programmable maximum timing for green light
• Usability in any intersection
• Cost Efficient and Reliable system
• Optimize hardware usage

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Specification

• Traffic control via timers and sensors
• Red-Red condition before any light turns green
• Always green on main road if no traffic at all
• Change to other state if no more traffic on
  current lane even though timer is not up yet
• Stay green if there is only traffic on current
  lane (ignoring max green time)
• No more unnecessary green
• Some more green time for right turn cars
• Flash red light if malfunction or power breakdown
  (Assume Backup Power will be available)

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Specification (cont.)

• Ability to adapt different settings between
  regular and rush hour
• Different maximum green time for each state
  between rush hour and regular hour
• Operate as regular hour in weekend
• Note All rush hours and max green timers are
  user programmable

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Specification (cont.)

• Pedestrian crossing lights for 4 crosswalks
• Always Red unless pedestrian cross request
• 3 types of pedestrian light signals which are
  Red, Blinking-Red White
• 7 segments countdown display

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Specification (cont.)

• Priority for Emergency vehicles
• Emergency vehicle detection sensors on all 4
  directions
• Green light on the direction in which emergency
  vehicle is heading (all other lights are red)
• Assumption
• Emergency vehicle detection sensors can detect
  ahead to get enough time for traffic control.
• Only one emergency vehicle is coming.

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Specification (cont.)

• Camera controller for red light crossing
• Detect and take picture of red light crossing
  vehicles

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Initial Behavior of the FSM

• Every state can go into any other states.
• Challenge All states need to have equal chances
  when traffic exists.

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Behavior of our FSM
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Behavior of our FSM
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Behavior of our FSM
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Behavior of our FSM
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Traffic Control State Diagram (Scenario 1)

• If theres no traffic on any of these states, it
  will change into opposite direction from any of
  these states
• Stay in the current state if theres no traffic
  on other states, but traffic on the current one.

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Traffic Control State Diagram (Scenario 2)

• If theres no traffic on any of these states, it
  will change into opposite direction from any of
  these states.
• Stay in the current state if theres no traffic
  on other states, but traffic on the current one.

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Traffic Control State Diagram (Scenario 3)

• If theres no traffic on any of these states, it
  will change into opposite direction from any of
  these states.
• Stay in the current state if theres no traffic
  on other states, but traffic on the current one.

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Traffic Control State Diagram (Scenario 4)
(Timer up or no car on ) and car on one of
the straight lanes
(Timer up or no car on straight lanes) and car on
Transition from opposite direction
Transition to opposite direction when timer up or
no traffic on this state
(Timer up or no car on )
and (cars on and no car on straight lanes)

• If theres no traffic on any of these states, it
  will change into opposite direction from any of
  these states.
• Stay in the current state if theres no traffic
  on other states, but traffic on the current one.

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Complete State Machine

• Since the opposite direction has the same
  behavior, we can optimized into 4 states for
  normal operation mode.
• Each direction can behave differently because
  they will have different maximum green timers.
• Pedestrian lights will be dependent on Traffic
  Control States and vice versa.

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Pedestrian State Diagram (Overview)

• Note Transition from Idle to any other states
  will be controlled by Traffic Control States.
• Return to idle state will be dependent on
  pedestrian timer.

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Block Diagram
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Components

• Traffic Light Controller
• Control pedestrian and all traffic flow
• Inputs
• 8 traffic sensors (1 bit)
• 4 emergency vehicle sensors (1 bit)
• 4 pedestrian request signals (1 bit)
• 4 max green timers (6 bits)
• Reset
• Clk

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Components (cont.)

• Traffic Light Controller
• Control pedestrian and all traffic flow
• Outputs
• 8 traffic lights (2 bits)
• 4 pedestrian lights (2 bits)
• 4 max green timer request (1 bit)
• 8 Camera arm signals (2 bits)
• Pedestrian timer (4 bits)
• Pedestrian state signal (3 bits)

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Components (cont.)

• Rush Hour Control Unit
• Determine when the rush hour is
• Inputs
• Set current time and rush hours (3 bits)
• Hour input (4 bits)
• Minute input (6 bits)
• AM/PM input (1 bit)
• Day input (3 bits)
• Rush hour switch1 (1 bit)
• Rush hour switch2 (1 bit)
• Data ready (1 bit)
• Reset and Clk
• Outputs
• Rush hour signal (1 bit)

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Components (cont.)

• Memory
• To store maximum green times for each lane
• Inputs
• Rush Hour signal (1 bit)
• 4 max green timer request (1 bit)
• Input Data Mode (5 bits)
• Input Data (6 bits) up to 63 seconds
• Clk
• Outputs
• 4 max green timers (6 bits)

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Components (cont.)

• 7 Segment Display Decoder
• To control 7 segment display
• Inputs
• Pedestrian timer (4 bits)
• Pedestrian state signal (3 bits)
• Outputs
• 4 Seven segment signals (14 bits)

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Components (cont.)

• Camera control Unit
• To signal cameras
• Inputs
• 8 Camera arm signals (2 bits)
• 8 Red light violation sensors (1 bits)
• Outputs
• 4 Camera to take picture signals (1 bit)

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Block Diagram
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Where the idea came from!
Any Better Idea?
Always have to go to Straight-Straight State to
change direction.
UnnecessaryGreen
Unbalanced.
Cannot go backward.
Skip the states that has no traffic !
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Where the idea came from! (cont.)

• Design of RAM Memory
• Processor Design (Lab 4)
• Design of Rush Hour Control Unit
• Alarm Clock Design

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Challenges

• We are still researching how to control if more
  than one emergency vehicles are coming.
• May be we are going to give priority to the
  emergency vehicle that is coming fast!
• May be we are going to flash yellow light!

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Tools

• Xilinx Webpack (VHDL)
• ModelSim (Simulation)
• Xilinx Webpack (Synthesis)

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Schedule

• Week 6 7 specification and design
• Week 7 8 VHDL development
• Week 8 9 Simulation/Testing Synthesis
• Week 10 Final Presentation

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Final Product Presentation

• Detail implementation
• Show the simulation of specific cases for
  correctness

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Contact us 3440 Lebon Drive San Diego,
CA 92122 Phone [phone] Fax [phone]
Thank You