View
39
Download
0
Category
Tags:
Preview:
DESCRIPTION
Dynamic Traffic Control. Group 2 Chun Han Chen Timothy Kwan Tom Bolds Shang Yi Lin Manager Randal Hong. Project Objective : Dynamic Control of Traffic Lights. Wed. Dec. 3. Presentation Outline. Marketing Project Description Design Process Floor Plan Evolution Layout - PowerPoint PPT Presentation
Citation preview
Dynamic Traffic Control
Group 2Chun Han ChenTimothy Kwan
Tom BoldsShang Yi Lin
ManagerRandal HongWed. Dec. 3
Project Objective :
Dynamic Control of Traffic Lights
Marketing Project Description Design Process Floor Plan Evolution Layout VerificationIssues Encountered Specifications
Presentation Outline
Marketing / Description
Tom Bolds
Current System
The current system has sensors that detects cars leaving their lanes Induction loops under the pavement Video cameras
Depending on the time of day, the intersection lets each arm go for a set amount of time
If no cars are present in one arm, the other arm is green
It cannot learn or adapt Cost for entire system: $35,000
A Better System
This system detects cars entering and leaving each arm
The time that an arm is green is determined in part, by past traffic
Exceptional traffic flow will change the system immediately
Cost for entire system: $24,000
Market
4 Million traffic lights in the USA few user inputs lets the system be
adjustable for different situationsRoads of different sizesDifferent space constraints
Price goes down and quality goes up
Goals
When the government is involved, cost needs to be low
Only 4 metal layers usedOptimized for small size
Could have gone the “all pseudo-nmos” route
We don’t want to use megawatts on a traffic light
Cmos logic to minimize size and power consumption
Goals
Even if it causes just a few accidents nobody will buy it, and we get sued
Design needs to be robust Handle power failures
Return to a known state Predictable behavior
People are used to driving a certain way No accidental switching
Minimum time for lights to change
Installation
The only change necessary would be the detectors for entering/leaving carsCurrent system has ground sensors or
video camera to detect the first car at an intersection
Could add another detector farther back, or use video/sound detection to determine where cars are
Traffic Flow
Sensors (Blue)To detect the car entered
Sensors (Red)To detect the car leaved
Traffic Light Flow
Whenever pedestrian push the button, then this light will insert in the end of this cycle.
ARM 1
ARM 2
Red
Green Y
Green (Straight + Right) Y Red+Green(Left)
Red
Y Red
Green (Straight + Right) Y Red+Green(Left) Y
Phase A
Phase C
Phase B Phase A Phase BARM1 ARM1 ARM2 ARM2
PED
We define three phases (A,B,C) for different operations.
Hold until n1 or n2 changes
Light favorsn1 or n2 ?
n1 n2
T<r1? T<r2?
T>= R1?
T>= R2?
n1=0?
n2=0?
f1<=0?
f2<=0?
Switch Light
ResetT = 0
No
Yes
Yes Yes
YesYes
Yes YesNoNo
No
No No
No
Yes
No
Light favorsarm1 or arm2 ?
n1 n2
T<rleft? T<rleft?
T>= Rleft? T>= Rleft?
No
Yes
Yes Yes
YesYesNo
No
Yes
Non1 not change in T = 5?
No
No
Control
reset Pedestrian For Green light
For Red + Left
T>= Rp ?
Yes
No
For Pedestrian
n2 not change in T = 5?
n1, n2 :# of carsT :Time spent in this phaseRi , ri : Max. and Min. time for each phasefi : the control functionf1 = α1*n1+ β1 – n2 f2 = α2*n2+ β2 – n1
SW – Switch light
G – Green
R – Red
Y – Yellow
T – Time for Yellow
PED – Pedestrian
SW (1bit)
ARM (1bit)
PED(1bit)
T (2bits)
Phase(2bits)FSM
Initial
G.R
Y.R
R+Left.R
Y.R
R.G
R.Y
R.Y
R.R+Left
PED
SW = 0 SW =0
SW = 1 SW = 1
T < 2 T < 2
T = 2 T = 2
SW = 1 SW = 1
SW =0
SW = 0
PED = 1
T = 2
PED = 1
T = 2
T<= 2 T<= 2
SW = 0
SW = 1
T = 2
PED = 0
T = 2
PED = 0
ARM = 0 ARM = 1
Init. Ped = 0Choose the Phase
Learning?
The way we learn is by changing beta To take out the division, multiply
everything else by Qlen
We are actually calculating f*Qlen, but it works since it only matters if it’s < 0
Qavg2Qlen
Qlen Qavg2
User Input Q
User Input R,r
Accum Reg
11
11
11ENTER
11
Accum Reg
1111
OUT /
LEFT
s0,s1: X 2
q0,q1: X 2
Reg X 10
1111
Reg X 10
2:1 MUX
110
110 11 X 10
11 X 9
11 X 1
q0q1
1111
11β
n1n0
11
1111
Q_len1111
16:1 MUX
4Sel
11
s0s111
11
1111
11
11
1111
1111
Sel4
N_avgαn0-n1
αn0
q0-s0
q1-s1
α0
α1
Q(αn0-n1)
ALU
2Sel_ALU
1:16 De-MUX
4
Sel
12 111
Reg X 9
12 bit
Reg X1
11 bit
n0n1
ROM
11
1111
β
2:1 MUX
12
n_avg
Q(αn0-n1)q1-s1
q0-s0
αn0
αn0-n1
11
F
α0,α1: X 2
ROM
Reg
Reg
8X8
8 X 8 8X8
11
11 11
8 X 8 : Dot Line to Comparator
R,r, RL,rl for Arm1 Arm2
11
½
2:1 MUX
Dot Lint to FSM
β
8 X 8
2 : 1 MUX
INT.
Compar1
FSMSW
ARM
CLK
Clear
FSM
1
Complete
ARM 1
ARM 2
PED1
2
2
½
11 11
ROM
11
11
User Input2:1 MUX
Reg11 11
Accmu8
1Clk Div.
8Accmu
1
Left-Turn Counter
T
8
88
Reg
Reg8
8
8
8
System Clock 1
PED 1
1
11
1
R & r, R_L& r_L
Sel_C
Ser_D
3
1
4X332 Sel_ALU
Sel_C
Sel
ARM
n0 = 0
n1 = 0
F <= 0
8 : 1 MUX
n0
n1
F
1 Sel_D
System Clock
Trigger, when cars go left turn
ARM
1
1 1
1
Shifting
Shifting1
Data Input
Initial Values
Clock
Operation
T, Left-Turn Counter
R, r, R_L, r_l
Flow Control FSM
Light Control FSM
Selection
Design Process
Shang-Yi Lin
Design Process – Objective
Goal - Compact Area
- Low Power Trade-Off - Performance
Behaviors / Flow Charts
Behavior Verilog / JAVA
Structural Verilog / Structure
Schematic / Cadence
Layout / Virtuso
Extracted RC / Simulation
Design Process - Overview
Finalize Chip Functionality- Make behaviors, function clear
Feasible & Reasonable Algorithm - Complex & Fast != Good Design
Design Process – Behaviors
Order of Traffic Light Traffic Light FSM Flow Control FSM
Design Process – Verilog / JAVABehavior Verilog & JAVA
Design Process – StructureBlock Diagram :
- Behavior Verilog to Structural Verilog - Data path and function blocks are determined- Initiate Floorplan
Floor Plan : - Routing Issue
Re-Use of Components :- Decrease Chip Area
Design Process – SchematicCompact Design :
- Minimize transistor count
Transistor Sizing :- Minimize transistor size- Equivalent Pull-Up & Pull-Down ability
Implementation : - Put reasonable output loads for simulation- Sized buffers for global control signals
Design Process – LayoutDefined the Metal Directionality :
- M1 & M2 : Local, power rails - M3 & M4 : Global, Control, Clock- Special Case : Depended
Focus on Compact Layout :- Floor plan keeps updating- Consider the interconnect between blocks
Global Routing :- Fixed height for most blocks - Use wider global wires- Leave wiring space
Block Level- Extracted RC simulation for each block - Combine multiple blocks to simulate
Chip Level- Ensure global signals integrity- Whole chip simulation
Design Process – Extract RC
Floorplan Evolution
Shang-Yi Lin
Floor Plan First Version
- Block Diagram- Sample Layout Size
Routing Issue Re-Use
Components
Register (1bit)2X1 MUX
16.613.5
6.5
6.6
InputGet q0 q1 s0 s1
Avg. q
½ , Q_L
FPU Output
Reuse
F , Ni
Give R,r Input PED, CLK
Compare T
Control Light
Floor Plan – 1st Version
Floor Plan – UpdateStructure : Logic components are determined
Layout : Refined Function Block
Floor Plan – Update
Refined LayoutMore Precise Layout Shape & Size
More and More
More and More…
Doing Global Routing
Final Layout
Layout / Verification
Chun Han Chen
Layout - ALU
Input Output
Layout – FSMs
Timing Control FSM
Light Control FSM
Counters
Shift Registers
MUX
Layout – Memory Devices & Interconnection Parts
Counters Shift Registers
and MUXs
Counters
Shift Registers
2:1 MUX
11-bits 16:1 MUX
Layout – Memory Devices & Interconnection Parts
Input
Select
Output
Layout – Memory Devices & Interconnection Parts
Real time counter, MUX, and, Comparator
Output to Timing Control FSM
Layout – Memory Devices & Interconnection Parts
Control + Registers
Control Logic
Output
Input from ALU
Layout – Whole Chip
Layout – Whole Chip
Verification – MethodologyFunctionality Validation
-Java V.S. Behavioral Verilog
-Behavioral Verilog V.S. Structural Verilog
Schematic Checks-Structure Verilog
V.S. SchematicLayout Verification
1.Whole chip extracted RC simulation by using Ultrasim
2.Comparing the results with schematic simulation
3.Separated simulations for pedestrian signal
Verification – Methodology Extracted RC for the whole chip
Verification – Light Switching
Switch
Continue
Verification – Pedestrian
Specification Issues Encountered
Timothy Kwan
Specifications Area = .146270 mm2
498.69 x 293.31 um^2 1:1.7002 Aspect Ratio
Transistors 18834 Total8613 pmos10221 nmos
Density .1288 transistors / um^2
Speed 10 MHz
I/O’s 74 inputs 5 outputs
Issues Encountered
MuxzillaLarge consecutive pass transistor muxes
Floor plan Increasing number of transistors led to larger
blocks12000 => 18834
Wire RoutingMetal DirectionalityLarge Number of WiresI/Os
Complicated FSM Logic and glitches
Issues Encountered
Large Fan Out in Some BlocksSystem Clock and Real Time Clock
Timing Issues Arithmetic Unit or Floating Point
UnitSimulation Issues
New vs. Old CadenceUltrasim vs. Spectre
?
Recommended