09 Shaver Ecosm12

8/10/2019 09 Shaver Ecosm12

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Robust Oxygen Fraction Estimation for

Diesel Engines Utilizing Variable Intake

Valve Actuation

Presented By:

Greg ShaverAuthors:

Lyle Kocher Karla Stricker

D. G. Van Alstine Greg Shaver

Herrick Labs

School of Mechanical Engineering

Purdue University

IFAC E-COSM12

Rueil-Malmaison, France

October 24, 2012


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2

Motivation for In-Cylinder Oxygen

Fraction Estimation

Oxygen Fraction Estimator

Development

Analysis Stability, Convergence,

and Robustness

Experimental Results

Conclusions

Presentation Overview

EGR VALVE

Exhaust

Intake Manifold

Exhaust Manifold

CAC

EGR Cooler

FRESH AIR


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5

Gas Exchange

Process

Combustion Process

Conventional

combustion

Advanced combustion

strategies (i.e. PCCI,

RCCI)

EGR valve

position

VGT

position

Intake Valve

modulation

Engine

speed

Exhaust gas

enthalpy

mIVC

Fcyl

ECR

TIVC

mixing

Fuel

Injection

Torque

Emissions

Fuel

consumption

Exhaust gas

enthalpy

Motivation for Oxygen Fraction Estimation

Gas Exchange Handshaking


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6


Fraction Estimation


Development


and Robustness


Conclusions


EGR VALVE

Exhaust

Intake Manifold

Exhaust Manifold

CAC

EGR Cooler

FRESH AIR


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Oxygen Fraction Dynamics

In-Cylinder O2

Can not directly measure but can estimate

me - trapped fresh charge mass

mres - trapped residual mass

Fem - proxy can be measured post-turbine

Fim - production viable sensor not available

e res emcyl

e res

im

m m F

m

FF m

120 ee

W

m N

em evc

resem

P V

m RT


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Oxygen Fraction Dynamics

imim amb c em egr im e

im im

RTF F W F W F W

P V

emem eo e f em egr em t em em

RTF F W W F W F W

P V

vol im d e

im

P VW

RT

- physically-based model

(incorporates impact of flexible

intake valve actuation)

Wegr - EGR Flow estimator

Wf - ECM commandWc - mass airflow sensor

Wt - analytical functions based

upon map data & man.

pressures and turbo speed

vol


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Fraction Estimation


Development


and Robustness


Conclusions


EGR VALVE

Exhaust

Intake Manifold

Exhaust Manifold

CAC

EGR Cooler

FRESH AIR


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Oxygen Fraction Estimator Analysis

im egr

im e em egr t

k WL

k W k W W l

2 2

2

1 1

2 2

2 2

im em

im e em em em em im e

V g g

V k W V k g g lg k W V

Choose:

Lyapunov

eqn.

candidate:

201

2

im ek W

im e

V t V t e

k W

2 2

em em em em em em em em em

em emem

em

lg k g g k g g k g

k gl k

g

em emg g g g A g k g L Cg EstimatorError:


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em em em

em

k gl kg

32 2132 1312 , 1350

0.5l l

em

k

For practical purposes,

Utilize knowledge of the physical system

to find bounds for physical parameters

Where reflectsup to a 10% error

in turbine flow

estimate

Parameters for calibration: Turbine mass estimate error:

Acceptable exhaust O2

estimation error:

0.5%em em em em emg g g F F is acceptable

emg

Oxygen Fraction Estimator Analysis


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Fraction Estimation


Development


and Robustness


Conclusions


EGR VALVE

Exhaust

Intake Manifold

Exhaust Manifold

CAC

EGR Cooler

FRESH AIR


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Oxygen Fraction Estimator Results2300 rpm & 522 N-m

Increase inEGR fraction

from ~ 12%

to 24%


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Oxygen Fraction Estimator Convergence2300 rpm & 522 N-m


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Fraction Estimation


Development


and Robustness


Conclusions


EGR VALVE

Exhaust

Intake Manifold

Exhaust Manifold

CAC

EGR Cooler

FRESH AIR


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In-Cylinder O2fraction is critical to control of combustion processes

Model-based observer designed for in-cylinder O2fraction estimation

AnalysisExponential stability results demonstrated, but rate dependent on operating point

Robustness to turbine flow estimation/measurement uncertainty demonstrated

Lower gain bound derived from expected turbine flow error & acceptable Femerror

Experimental results shown for in-cylinder oxygen fraction estimator

Future workexplore possible extension to: Robustness to other uncertainties (e.g., EGR flow, fuel flow, etc.) Tunable error convergence rates

Is there an upper gain bound? Very likely. What is it, and why?

Conclusions


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EGR Flow calculation from ECMnot reliable at higher EGR Flows

Developed high gain estimator

strategy based upon the intakemanifold filling dynamics

im im im imim comp cac eng im egr egr im im

R Rp W T W T W T

V V

im im

egr

im im egr

V pW

R T

2im im comp cac eng im imim

RW T W T p

V

EGR Flow Estimator

09 Shaver Ecosm12

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