2. About Me
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University of Texas at Austin
– B.S. Electrical Engineering May 2017
Born in Cincinnati, Ohio and moved
to Austin, Texas at 6 years old
Eagle Scout and 4 years of high
school robotics in FIRST Robotics
Competition
Founding member of UT FSAE –
Electric
Co-creator of Innovation Station, a
3D Printing Vending Machine
3. Terminology and Background
PIP (pre-injection processing)– 10 kHz pressure data accumulator
PIP Tool – Engineering tool used to download pressure buffers for
analysis
Ring Buffer – Circular buffer that holds 2000 most recent pressure
samples
PIP Buffer – Sample of ring buffer prior to injection event
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4. Major Project
Problem
– PIP Tool displays single
pump cutout events and
injection events
– Unexplained offsets in
pressure in between
injection events
– Pressure data is only visible
through PIP buffer during
pump cutouts
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Pressure variations
5. Major Project
Objectives
– Develop code and analysis script to view
continuous pressure data from ring buffer
– Collect and compare pressure data between ring
buffer and PIP buffer to validate PIP buffer
– Investigate 16-bit SDADC to potentially resolve
the issue
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6. Major Project – Data Collection
Actions
– Studied PIP buffer C code to
identify relevant functions
– Used portable bench to verify
functionality of data collection
– Progressed to closed-loop bench
to collect real data
– Forced to collect 200 elements at
a time because of software
limitations imposed by Veristand 6
7. Major Project – Data Analysis
Actions
– Piece together each 200 element segment of ring buffer in
MatLAB
– Plot and identify pump cutout events in ring buffer
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8. Major Project
Results
– Software and Test team has new ability to view continuous
pressure data from ring buffer
– Ring buffer’s validity will be confirmed
Future
– Software and Test team may implement 16-bit SDADC
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10. Takeaways
Familiarity with many software and engineering tools
Fuel system in diesel engines and fuel system specific controls
Functionality of PPT, Software, Test, and Applied Controls teams in
FSSC
Work process and workflow in FSSC
Connection of control theory and coursework
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Sanjai Bashyam– worked as a controls engineer
Fuel System Controls
Software and Testing Team
Manager Nate Linen
UT BSEE – May 2017
Born in Cincinnati, moved to Austin at 6 and now college in Austin
Eagle Scout and heavy high involvement with FIRST robotics and Innovation Station (expand)
Brief involvement in UT FSAE – Electric, founding member of the team
Pre-injection processing – pressure data prior to injection
Pip buffer – sample of ring buffer prior to injection event
Pump cutout is closing IMV valve to stop fuel from tank to pump
Pump cutout creates a stable pressure before injection events so that we can accurately see pressure drops and calculate fuel injected without sudden spikes due to pumping
Don’t see it on a real engine
Ring buffer 2000 elements that updates every 200ms
1 bar= 1.4 mv 1mv=3 mg of error in fuel
each step is only .8 bar so about 1.2mv
the error we are seeing is 2-3 bar? mv? so its only a few steps wide
Code and analysis script to view continuous pressure data through ring buffer rather than periodic pressure data through PIP Buffer
Ring buffer 2000 elements that updates every 200ms
Fixed rate still ran at 20ms which luckily allows for collecting of 2000 element buffer 10 times before it is filled. 200 elements at a time
Needed to find start, end, and current position in the ring buffer to collect the data
EvtGetPipBuffPtrs and get_triggered_status create the pointers to the ring buffer
Piggyback on EvtQADCFixedRate because it runs every 20ms no matter what, more than often enough to collect data in ring buffer which updates every 200ms
Portable bench controls pressure manually with a potentiometer, creates smooth lines as soon in the plot on the right
Data processing in matlab to stitch together each 2000 element ring buffer
Fixed rate still ran at 20ms which luckily allows for collecting of 2000 element buffer 10 times before it is filled. 200 elements at a time
Open’s door for new methods of testing and analysis without viewing pump cutout events
Steady voltage and view ring buffer continuously to see any fluctuations
Tools – Calterm, Canape, Veristand, PIP Tool, MatLAB C2ST, BuildForge
Software team creates the new software, test team will verify that the functionality is there and applied controls will work with customers and ensure functionality is still working
Control theory and how algorithms like PID and closed-loop vs open-loop algorithms are applied into a fuel system
Time each one took to help me learn tools processes and systems
