Transcript Document

Team W3:
Anthony Marchetta
Derek R. Ritchea
David M. Roderick
Adam Stoler
Overall Project Objective:
Design an Air-Fuel Ratio Controller
For a small gasoline engine with
Low emissions and low cost
Design Manager:
Steven Beigelmacher
Milestone 1:
Jan 21st
Project Proposal
Status
• Design Proposal (done)
• Architecture (in progress)
• To be done
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Floorplan
Gate Level Design
Component Layout
Chip Layout
SPICE Simulation of Entire Chip
Introduction
• Electronic Fuel Injection Systems were developed
to replace carburetors in automobile engines.
• Carburetors are still used in smaller gasoline
engines for things like chainsaws and
lawnmowers.
• We want to design the ECU component of a fuel
injection system to regulate the Air to Fuel ratio in
small gasoline engines.
• Electronic Fuel Injection makes an engine more
efficient and more environment-friendly. They
allow engines to meet emission standards.
Market Demand
• Why Electronic Fuel Injection
• Lower emissions coupled with increased power
and efficiency.
• No more cold start problems.
• More reliable engine.
• Our Product
• Low cost replacement for carburetors
• Increased Efficiency
• Environmentally friendly
Design Decisions
• Inputs: 12-bit signals from engine sensors:
• Manifold absolute pressure sensor – used to
calculate load on engine
• Engine Speed sensor – monitors engine
speed
• Throttle position sensor – measures air intake
of engine and changes fuel rate as necessary
• Oxygen sensor – monitors oxygen in exhaust
to change fuel rate if necessary
• Output: 12-bit Pulse Width to Injector
Design Decisions
• Basic Algorithm
• Base pulse width calculated with a look up
table using load and speed sensors.
• Additional inputs use modifiers from look up
tables that multiply base pulse width.
• Final pulse width controls the amount of fuel
injected into the cylinder
• New level calculated before each revolution
Design Decisions
• Whether to use SRAM or ROM for look-up
tables.
• Bit size of inputs and multiplier
• Type of multiplier to be used
• Need comparators and/or decoders for
look-up tables.
Proposed Design
Engine
Speed
Manifol
d
Pressue
12bit
Input
Reg
12bit
Input
Reg
Control
Logic
8X8 SRAM
Look-up
2:1M
ux
%Oxyg
en
12bit
Input
Reg
8X1
SRAM
Lookup
Throttle
Position
12bit
Input
Reg
8X1
SRAM
Lookup
2:1M
ux
Array Multiplier
12bit Output
Register
Other
inputs?
??
Transistor Count
Registers (5 12-bit)
2,040
SRAMS (1 8x8, 2 8x1)
5,760
Comparators (4)
1,472
MUXs (2)
336
12-bit FP Multiplier
3,412
Control Logic
500
TOTAL
13,520
Alternative Designs
• Poker Probability Prediction
• Not very practical or applicable
• Pulse Oximetry (oxygenation of blood)
• Too complex
• Encryption / Compression Algorithms
• Been done before
Problems & Questions
• Problems
• Low Transistor Count
• Possible Solutions
• Add more inputs (temperature, voltage)
• Increase signal size (16-bit?)
• Add special logic for specific cases
• Startup
• Idling