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Technical Advisor Advanced Engineering

Estimation and Control of Diesel Engine Processes Utilizing Variable Intake Valve Actuation

Lyle E. Kocher

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• Experimental Test Bed • Model Based Approach • Gas Exchange Model

• Manifold Filling Dynamics • Volumetric Efficiency • Oxygen Fraction Dynamics

• Combustion Model

• PCCI Combustion Timing Model • Controller Development

• PCCI Combustion Timing • Summary

Presentation Overview

VGT Position

EGR Valve Position

EGR VALVE

Exhaust

Intake Manifold

Exhaust Manifold

CAC

IVC Modulation

Fueling

EGR Cooler

FRESH AIR

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2010 Cummins ISB • 360 HP (268 kW) • 17.3:1 Compression Ratio • Common Rail Fuel Injection • Air-Handling System

• Exhaust Gas Recirculation Valve • Variable Geometry Turbocharger

• Variable Valve Actuation System • Electro-Hydraulic System • Cylinder Independent • Cycle-to-cycle

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Gas Exchange Process

Combustion Process

• Conventional combustion

• Advanced combustion strategies (i.e. PCCI, LTC)

EGR valve position

VGT position

Valve Timing

Engine speed

Exhaust gas enthalpy

mIVC

[O2]IVC

ECR

TIVC

“mixing”

Fuel injection

Torque

Emissions

Fuel consumption Exhaust gas

enthalpy

Model Based Approach

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• Physically-based generalizable models • Validated experimentally • Validated via analysis (math-based stability, convergence rate, and sensitivity/uncertainty analysis)

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• 5 Model States • Intake Manifold

• Pressure • Temperature

• Exhaust Manifold • Pressure • Temperature

• Turbo Shaft Speed VGT

Position

EGR Valve Position

EGR VALVE

Exhaust

EGR Cooler

Intake Manifold

Exhaust Manifold

LFE AIR FILTER FRESH AIR

CAC

Intake Valve Modulation

Fueling Commands

Gas Exchange Model

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Intake Manifold State Equations

Exhaust Manifold State Equations

Turbocharger Speed State Equation

( )im imim egr egr c cac e im

im

Rp W T W T W TV

γ= + −

( ) ( ) ( )im imim egr im egr im c im cac im e im im im

im im

R TT W T T W T T W T TP V

γ γ γ = − + − + −

( )exh exhem e f exh egr em t em

em

Rp W W T W T W TV

γ = + − −

( )( ) ( ) ( )em emem e f em exh em egr em em em t em em em

em em

R TT W W T T W T T W T TP V

γ γ γ = + − + − + −

m turb comptc

turb tc

P PI

ηω

ω−

=

Gas Exchange Model

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Volumetric Efficiency Model

Exhaust Enthalpy Model

Analytical Turbocharger Performance Functions

( )1

1 ea

e a

kkf LHVim e

evo tdck kc im evo e im

a N b m Qp kECRT Vm R V k P ECR−

⋅ + −= +

2e im vol dNW Vρ η=

( ) ( )( ) ( )

, ,

, ,c c turb t t turb

c c turb t t turb

W f PR N W f PR N

f PR N f PR Nη η

= =

= =

Gas Exchange Model

( ) ( ) ( )eff

ef ivo ivf c

ivcim ivc em ivo em evc ivo im i

k

v v p ivo ivc s

vol

vc ivo wall imivc

im d p

VP V P V P V V P V V T T

Vc c

c

R

P

c R h

V

A

η−−

− − − +

− − −

=

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Volumetric Efficiency Model Results

± 5% Lines 2.5% RMS Error

Gas Exchange Model

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1850 RPM, 300 ft-lb

Gas Exchange Model Results

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imim amb c em egr im e

im im

RTF F W F W F WP V

= + −

( )emem eo e f em egr em t

em em

RTF F W W F W F WP V

= + − −

Gas Exchange Model

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Gas Exchange Model

Oxygen Fraction Estimator Results

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Start of Combustion Prediction

Red lines are ± 2°CA

PCCI Combustion Timing Model

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• What needs to be controlled to control PCCI combustion timing?

• Can we separate dynamics?

Slower dynamics driven by gas exchange process

Faster dynamics driven by fuel injection process

PCCI Combustion Timing Model

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1600 rpm & 140 ft-lbf Fim Command Step Change

PCCI Combustion Timing Controller

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1600 rpm & 140 ft-lbf SOC Command Step Change

PCCI Combustion Timing Controller

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• Experimental Test Bed • Model Based Approach • Gas Exchange Model

• Manifold Filling Dynamics • Volumetric Efficiency • Oxygen Fraction Dynamics

• Combustion Model

• PCCI Combustion Timing Model • Controller Development

• PCCI Combustion Timing • Summary

Summary

VGT Position

EGR Valve Position

EGR VALVE

Exhaust

Intake Manifold

Exhaust Manifold

CAC

IVC Modulation

Fueling

EGR Cooler

FRESH AIR

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