Engine Systems - ETH Zürich Hedinger | 26.09.2016 | 10 Air-to-Fuel Ratio Feedback Control Three Way...
Transcript of Engine Systems - ETH Zürich Hedinger | 26.09.2016 | 10 Air-to-Fuel Ratio Feedback Control Three Way...
||
Prof. Chris Onder
Norbert Zsiga
Raffi Hedinger
Michael Zihlmann
26.09.2016Raffi Hedinger 1
Engine Systems
||
Chris Onder, Professor
ML K37.2, Tel. 044 632 24 66
Norbert Zsiga, PhD Student
ML K41, Tel. 044 632 25 94
Raffi Hedinger, PhD Student
ML K41, Tel. 044 632 49 39
26.09.2016Raffi Hedinger 2
People
If you have any questions: come and ask!
|| 26.09.2016Raffi Hedinger 3
Structure
Lectures
Exercises (Practical and Theoretical)
Time and Place Monday, 8:15h-10:00h, ML F 38
Presenter Prof. Onder
Intake Manifold Idle Speed Controller Design Process
Theory Exercises
Time and Place Monday, 12:15h-13:00h, ML H 41.1
Presenters Norbert Zsiga, Raffi Hedinger
Start of Semester End of Semester
|| 26.09.2016Raffi Hedinger 4
Off topic: Fisita Travel Bursary Programme
More information: http://www.fisita.com/education/bursary
Swiss Delegate: Chris Onder
2000 € for ICE
internship abroad
||
Why?
Modeling?
Controls?
How?
26.09.2016Raffi Hedinger 6
Modeling and Control of Internal Combustion
Engine Systems
||
1943: Beginning of huge smog problems in Los Angeles
1950: Caltech researchers identify problem: unburned hydrocarbons in the air
1956: US Clean Air Act
1975: Catalytic converters are mandatory equipment for cars in the US
26.09.2016Raffi Hedinger 7
The Birth Hour of Modern Engine Controls
|| 26.09.2016Raffi Hedinger 8
Catalytic Converters
Emissions
Unburned hydrocarbons (𝐻𝐶)Nitrogen Oxides (𝑁𝑂,𝑁𝑂2: 𝑁𝑂𝑥)Carbon Monoxide (𝐶𝑂)
“Clean Air”
Water 𝐻2𝑂Carbon Dioxide (𝐶𝑂2)Nitrogen (𝑁2)
Perfect
Three Way Catalytic Converter
1943: Beginning of huge smog problems in Los Angeles
1950: Caltech researchers identify problem: unburned hydrocarbons in the air
1956: US Clean Air Act
1975: Catalytic converters are mandatory equipment for cars in the US
Smog
Acid rain
Death (0.04%: 3 hrs)
||
1.110.9 λ [−]
conversion
efficiency
stoichiometrylean:
too much air
rich:
too much fuel
26.09.2016Raffi Hedinger 9
Catalytic Converters
1943: Beginning of huge smog problems in Los Angeles
1950: Caltech researchers identify problem: unburned hydrocarbons in the air
1956: US Clean Air Act
1975: Catalytic converters are mandatory equipment for cars in the US
1976: Bosch presents first air-to-fuel ratio sensor for use in cars
𝜆 =𝑚𝑎𝑖𝑟
𝑚𝑓𝑢𝑒𝑙 ⋅ 𝜎0
𝜎0 = stoichiometricair
fuelratio
|| 26.09.2016Raffi Hedinger 10
Air-to-Fuel Ratio Feedback Control
Three Way Catalytic Converter
1943: Beginning of huge smog problems in Los Angeles
1950: Caltech researchers identify problem: unburned hydrocarbons in the air
1956: US Clean Air Act
1975: Catalytic converters are mandatory equipment for cars in the US
1976: Bosch presents first air-to-fuel ratio sensor for use in cars
add more or less
fuel to reach
stoichiometry
feedback
control
loop
air-to-fuel ratio
sensor
Exhaust mass flow
|| 26.09.2016Raffi Hedinger 11
Basic Engine Sensors and Actuators
TWC
Tank
1 2
TWC
throttle
intake
manifold
fuel
pump
injector
spark
plug
air-to-
fuel ratio
sensor
three way
catalyst
piston
air mass
flow meter
knock sensor
engine speed
driver pedal position
Engine Control Unit
|| 26.09.2016Raffi Hedinger 12
Modern Engine Feedback Control
air-to-fuel ratio
sensor 𝐶𝜆injection
duration
• Emissions
• Safety of engine components
• Efficiency?
|| 26.09.2016Raffi Hedinger 13
Engine Efficiency
0.1
0.2
engine efficiency =0.25
0.3
0.330.350.36
engine
torque
engine
speed
|| 26.09.2016Raffi Hedinger 14
Engine Efficiency
0.1
0.2
engine efficiency =0.25
0.3
0.330.350.36
engine
torque
engine
speed
Downsizing
and supercharging
|| 26.09.2016Raffi Hedinger 16
Modern Engine Feedback Control
air-to-fuel ratio
sensor 𝐶𝜆injection
duration
• Emissions
• Safety of engine components
• Efficiency?
• Desired load torque
• Knocking
• Center of combustion
• Boost pressure
• EGR rate
• Valve timing
• Fuel pump
• Water pump
• ...
driver pedal position
Engine Control Unit
||
Why?
Modeling?
Controls?
How?
26.09.2016Raffi Hedinger 19
Modeling and Control of Internal Combustion
Engine Systems
|| 26.09.2016Raffi Hedinger 20
Best Possible Model Based Controller Designdriver pedal position
Engine Control Unit
TWC
Tank
1 2
TWC
throttle
intake
manifold
fuel
pump
injector
spark
plug
air-to-
fuel ratio
sensor
three way
catalyst
piston
air mass
flow meter
knock sensor
engine speed
|| 26.09.2016Raffi Hedinger 21
Best Possible Model Based Controller Design
TWC
Tank
1 2
TWC
injector
air-to-
fuel ratio
sensor
|| 26.09.2016Raffi Hedinger 22
Best Possible Model Based Controller Design
𝑇90
𝜆 signal, instantaneous fuel mass decrease at 𝑡 = 0
Time
𝑡 = 0
𝛥𝑡
|| 26.09.2016Raffi Hedinger 23
Best Possible Model Based Controller Design
𝛥𝑡
𝑇90𝑇90
Time
𝑡 = 0
𝛥𝑡
𝜆 signal, instantaneous fuel mass decrease at 𝑡 = 0
|| 26.09.2016Raffi Hedinger 24
Best Possible Model Based Controller Design
𝛥𝑡
𝑇90𝑇90
Time
𝑡 = 0
𝛥𝑡
Internal Model
Controller𝜆
Δ𝑡, 𝑇90
Controller
Output
ctrl. speed
𝜆 signal, instantaneous fuel mass decrease at 𝑡 = 0
|| 26.09.2016Raffi Hedinger 25
Standard Model Based Controller Design
Procedure
1. Create physically based mathematical model
2. Get engine running
3. Take measurements for identification and validation
4. Use model to design and tune controller
Benefits of physically based model
1. Theoretical stability analysis is possible
2. Offline controller tuning
3. Model-based optimal control
4. Can be used for other engines, too
5. Model can be used for feedforward control
||
Why?
Modeling?
Controls?
How?
26.09.2016Raffi Hedinger 27
Modeling and Control of Internal Combustion
Engine Systems
||
Objectives
Understanding of physical processes in
engines
Derive simplified models suited for model-
based control
Content
Mathematical models of most important
engine components (continuous time)
Discrete event models (discrete time)
Controller design case studies
26.09.2016Raffi Hedinger 28
The Lecture
80% Modeling 20% Control
|| 26.09.2016Raffi Hedinger 29
The Lecture
# Content
0 Extra Introductory Lecture
1 Introduction, Goals, Administration, Examples
2 Models I: Causality Diagrams, Air Path
3 Models II: Air path, Fuel path, A/F dynamics
4 Models III: Torque Production
5 Test Benches, Sensors, Actuators
6 Models IV: Thermal Models
7 Models V: Emissions, TWC
8 Models VI: Emissions, SCR
9
Models VII: Discrete Event Modeling, Introduction, Crank-angle Based Modeling, Hardware,
Interpretation of Measurements, Torque production, Air Mass Estimation, Fuel Path, Exhaust Gas
Mixing, EGR-Model
10 Guest Speaker
11 Modern Engine Control Units, Torque Based Structure, A/F Control: Feedforward Evaluation
12 A/F control: Feedback: Switch-Type Control, Wide Range Control, MIMO-Control, Evaluation
13 SCR Control, Thermomanagement Control
||
Objectives
Apply knowledge from the lecture
Content, theoretical part
Gain better understanding of the
theory from the lecture
Content, practical part
Design model based idle-speed
for a 5-cylinder engine
Take your own measurements on
the test bench
Competition at end of semester
26.09.2016Raffi Hedinger 33
The Exercises
|| 26.09.2016Raffi Hedinger 35
Idle Speed Control Problemdriver pedal position
Engine Control Unit
TWC
Tank
1 2
TWC
throttle
intake
manifold
fuel
pump
injector
spark
plug
air-to-
fuel ratio
sensor
three way
catalyst
piston
air mass
flow meter
knock sensor
engine speed
|| 26.09.2016Raffi Hedinger 36
Idle Speed Control Problem
air-to-fuel ratio
sensor 𝐶𝜆injection
duration
Engine speed 𝐶𝑀𝐼𝑆𝑂injection duration
ignition timing
||
Why?
Modeling?
Controls?
How?
26.09.2016Raffi Hedinger 39
Modeling and Control of Internal Combustion
Engine Systems
|| 26.09.2016Raffi Hedinger 40
Structure
Lectures
Exercises (Practical and Theoretical)
Time and Place Monday, 8:15h-10:00h, ML F 38
Presenter Prof. Onder
Intake Manifold Idle Speed Controller Design
Theory Exercises
Time and Place Monday, 12:15h-13:00h, ML H 41.1
Presenters Norbert Zsiga, Raffi Hedinger
Start of Semester End of Semester
||
General
Class facts sheet online
Class text book will be distributed as .pdf file
Oral exam, 30min, during examination session
Exercises
Work in groups of 4 people
Exercise instruction script available online
Controller performance competition at end of semester
Win pizza voucher
Exercises are not mandatory
26.09.2016Raffi Hedinger 41
Useful Information