Transcript Automotive Control Solutions
Automotive Control Solutions Russell Potter – CTO, President Alex Gutica - CFO Brian Nelson - CTO
Automotive Control Solutions
The AF Optimizer - An ENSC440 project -
Contents
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The ACS Team The AF Optimizer The 440 project In-car Demo Now The future Conclusion Questions?
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Automotive Control Solutions
A cutting-edge development team specialize in control of automotive performance through electronic air/fuel optimization Appeal to owners of any car, particularly older vehicles with simple electronic control 3
Who Are We?
User Interface Firmware Lead Russell Potter DSP Firmware Lead Alex Gutica Hardware Lead Brian Nelson 4
Internal Combustion Engine
Requires a correct mixture of fuel and air in order to function Fuel is mixed with the air, compressed, and ignited. When ignited, the air/fuel mixture drives pistons down, which turns a crankshaft.
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Fuel Delivery
The most efficient burn mixture has an 14.7:1 air-fuel ratio.
The lean condition The air-fuel ratio is too high Results in detonation, power loss, increased emissions The rich condition The air-fuel ratio is too low Results in reduced economy, increased emissions, power loss 6
Fuel Injection System
Proper fuel delivery is electronically controlled through a fuel injection and ignition timing system 7
Based on a 2 variable present map in the ECU Load/Airflow meter RPM
Fuel Delivery
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The Problem
Fuel maps and fuel delivery are designed for compromise By modifying fuel delivery and consequently air fuel ratios, improvements can be made Performance Economy Improved Emissions 9
Why Modify an Already “Tuned” System?
Are the original engineers incompetent?
No but, the original characteristics of the motor can be changed Performance enhancements Changing the amount of air\fuel flowing into the motor General engine wear Perhaps a different “compromise” is desired 10
Current Solutions for Modifying Air Fuel Ratios
Modifying the computer: new fuel maps Model-specific Costly Lack of user-specific ability to tune Standalone systems Complete computer replacement is very intrusive Requires extensive, expensive tuning Mechanical solutions Rudimentary APEXi SAFC Our direct competition 11
The AF Optimizer
Its functionality and potential market Its competitive edge Features System Design and Implementation Hardware and firmware 12
The AF Optimizer
What does it do?
Recalibrates air flow sensor data, while monitoring car Allows for flexible tuning of air fuel ratios Moves to different location on original fuel map Monitors automobile sensors with real-time visual display to users Why would one buy it?
To inexpensively and safely optimize delivery of fuel to their engine 13
Target Market
Customer needs to tune their fuel system Desires better performance Wants a simple, noninvasive install 29 Billion Dollar aftermarket part industry Our target demographic is young people With older cars Who demand an inexpensive, feature packed fuel control system 14
Compatibility
Compatible with wide range of manufacturers Required: Fuel injection MAP or VAF sensor 0-5V Scale Reality: Older, simple computer is better 15
AF Optimizer Advantages
First and foremost, price Versatile for use on many different vehicles Easy to install and remove Un-intrusive to the vehicle Real-time monitoring Works on older cars 16
Feature Overview
Airflow tuning features Shift Light Features Monitoring Features 17
Tuning Features
Many Tuning points provides more tunability based on RPM and Throttle % RPM Tuning 2000-8750 RPM - 250 RPM increments 75% to 125% - 1% increments Linearly Interpolates between tuning points 3000 3250 3500 3750 >102% 110% 109% 107% 98% 100% 97% 98% 18
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Tuning Features
Throttle Percentage Tuning 2 Calibration Curves: High / Low Throttle User defined - based on throttle % thresholds Throttle Thresholds Low: e.g. <30% throttle High: e.g. >90% throttle Linearly interpolates between the thresholds 20
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Tuning Features
Overall: 2-Dimensional interpolation RPM and Throttle % are variables 22
Shift Light Features
2000-10000 RPM in 100 RPM increments 5 Sequentially lit LEDs LEDs light up every 100 RPM as you approach your desired shift point Increasing brightness Example where shift light set to 5000 RPM 23
Monitoring Features
Real-time monitoring of engine’s sensors RPM Throttle % Battery Voltage RPM: 3250rpm Throttle: 80% Battery: 14V O2 Sensor: 220mV O 2 Sensor Voltage Airflow and calibration monitoring Calibration % Pre and Post Airflow Voltages Airflow: 106% Pre: 2050mV Post: 2184mV 24
RPM Sensor Throttle Sensor
System Overview
ECU Airflow Sensor AF Optimizer
Component and System Layout
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AF Optimizer: Hardware
Part Sourcing PIC 16F Microcontroller Maxim 10-bit DAC Noritake 4-line x 20 character VFD 5Volt Regulator Input Circuitry 26
Hardware Challenges
PIC Microcontroller Need to service the display, inputs and DAC fast Fast speed for calculations DAC Accuracy Power Management I/O conditioning Noisy car signals, voltage scaling Creating a stable, fast analog output with DAC 27
AF Optimizer: Firmware
Performed two functions Sample inputs, calculate, output Handle interaction with user Buttons Display Written in C High level functionality Easy writing, debugging Memory & Processor Usage 28
Firmware Challenges
Debugging and Simulation Simulator has limited functionality PIC was new to us Timing We had strict timing demands Needed all three hardware timers Required very careful time management 29
Final Product Performance 1
Successful integration into the vehicle was dependent upon system response speed Response to a 16Hz sine as airflow input (unrealistic, but illustrates system performance) 30
Final Product Performance 2
A more realistic response to a square wave 1.5 ms system delay Small capacitor used to eliminate discontinuities 31
Integration Challenges
Very smooth integrating into the car Research of sensor signals In-car signal testing with oscilloscope Great lab setup for proper simulation Start up and Connection issues Starter draws current and dropped the battery voltage FIX: Cap and diode Bad connections with breadboard and car wiring FIX: Soldered car wiring harness & PCB Car has a bad O 2 Sensor 32
Demo Time
Things to demonstrate: Monitoring How to setup throttle values Shift light How to set airflow calibrations Car running and driving Out to B-LOT everyone 33
Dyno Results
Very Impressive Results!!
Running too rich loses power.
Running too lean loses power… We are able to change the air fuel ratios Here are the results 34
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Baseline Run
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Rich Run
Tried 120% but threw Check Engine Light Tuned to 110% from 2000-6700 RPM (redline) Results: 37
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Rich Run
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Lean Run
Running too lean lost power in low RPMs Original ECU runs too rich at high RPMs Use AF Optimizer to lean high RPMs Results: 40
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Engineering Considerations
Positive system feedback due to vehicle velocity Does not affect airflow into engine Dynamometer is appropriate for vehicle tuning System memory considerations (derivatives) Precautions were taken to prevent derivative reversal Airflow signal adjustability range limited to 75% - 125% High and low throttle curves at least 20% of entire throttle range apart Testing indicates airflow signal changes much faster than throttle 43
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Budget
Proposed Budget: Actual Spending: Difference: $665 $200 $-465 Summary We
UNDERSPENT!
Due to building only 1 prototype, cheap dyno time 45
AF Optimizer: Schedule
Predicted Completion Dates
Firmware:
February 27
Hardware: System Integration:
March 13
Final Testing:
March 6 March 24 Actual Completion Dates March 15 March 6 March 17 April 4
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AF Optimizer: Now
Have a fully functional prototype!
We’ve priced many parts in quantities The display dominates Accounts for as much cost as all others combined Produced prototype PCB and casing Plans underway for production model Designed to use 1 PIC for cost 47
AF Optimizer: The Future
Small distribution at first Use online car clubs for marketing Will hopefully get feedback If all goes well, incorporate!
Outsource manufacture to overseas Build relationships with distributors Maybe make a few $$ 48
Future Design Considerations
Split it up into modules Display and buttons Main PC Board and wiring to car’s wiring Shift light (remotely mounted) Optimize PCB designs 49
ACS Team Summary
This was a great learning experience Conclusions Acknowledgements 50
Lessons Learned
Time and hard work invested early pays off Research allows for easier problem solving Documentation is important for complicated projects 51
Conclusions
We chose a great project Because we love cars It was complex, but workable We honed our skills learned in 4 years This product can make money 52
Acknowledgements
Scott, Lucky, Fred Dave Atchison, for experience with PIC and Dyno time ESSEF funding 53
Questions?
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