Team W3: Anthony Marchetta Derek R. Ritchea David M. Roderick Adam Stoler Milestone 1: Jan 21 st Project Proposal Overall Project Objective: Design an Air-Fuel Ratio Controller For a small gasoline engine with Low emissions and low cost Design Manager: Steven Beigelmacher

Status Design Proposal (done) Architecture (in progress) To be done 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 12bit Input Reg 8X8 SRAM Look-up 8X1 SRAM Look- up Array Multiplier 2:1M ux 12bit Output Register 8X1 SRAM Look- up 12bit Input Reg 12bit Input Reg 12bit Input Reg Control Logic Engine Speed Manifol d Pressue %Oxyg en Throttle Position Other inputs? ??

Transistor Count Registers (5 12-bit)2,040 SRAMS (1 8x8, 2 8x1)5,760 Comparators (4)1,472 MUXs (2) bit FP Multiplier3,412 Control Logic500 TOTAL13,520

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