Post on 11-Aug-2020
DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Claus Schnabel (PI)
Award: DE-EE0005975 Sensors and Ignition Project ID: ACE091 Robert Bosch LLC
2015 DOE Vehicle Technologies Program ReviewWashington, D.C.
June 11, 2015
This presentation does not contain any proprietary, confidential, or otherwise restricted information1
DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Project OverviewPartners
Timeline
US Department of Energy
Robert Bosch LLC
Clemson University
Oak Ridge National Lab
Target is to develop an Intake Air Oxygen (IAO2) sensor which directly and accurately measures the oxygen concentration in the intake manifold and demonstrate its potential.
Barriers are• Inadequate data on requirements and risks
concerning sensing with IAO2 • Control Strategies utilizing IAO2 sensing
$4,446,686 – Total Project Budget$2,750,000 – DOE Funding$1,696,686 – Partner Funding
$4,137,184 – Actual expenditure (as of 03/2015)$2,506,501 – DOE Funding$1,630,683 – Partner Funding
$ 309,502 – Remaining (as of 03/2015)$ 243,499 – DOE Funding$ 66,003 – Partner Funding
Project Overview REGIS
Sensor Development
Baseline Sensor EvaluationDesign Development
Design DevelopmentValidation
Validation
System Evaluation
cEGR System EvaluationRequirements Sensor
Demonstration of potential
cEGR Control StrategyControl Algorithm Development Validation
2013-Phase I 2014-Phase 2
Budget
Target & Barriers
2015-Phase 3
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Objectives and RelevanceObjectives• Develop an Intake Air Oxygen (IAO2) sensor which directly and accurately
measures the oxygen concentration in the intake manifold
• Demonstrate the potential of the sensor in combination with system adaptation and cEGR control strategies in a target engine application
Relevance of cEGR• cEGR enables improved fuel economy in most driving conditions
(on and off cycle) supporting the mainstream trend of Downsizing
• Improvement of up to 5% in engine peak thermal efficiency
• Other future combustion technologies will utilize cEGR
Relevance of IAO2• IA02 aims at providing a significant improvement in control accuracy of
cEGR to maximize the fuel economy potential of the system
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Approach - REGIS
Sensor Development and Design
Controls & Software
System evaluation
Development of an IAO2 sensor for EGR control and demonstration of benefits
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Collaborators and Partners
System level evaluation cEGR Control Development Proof of Potential
Funded by DOE 430 T USDOwn Funding 115 T USD
Derivation of requirements Development and Validation Sensor Built of Sensor Prototypes Validation Control Strategy
Funded by DOE 2,140 T USDOwn Funding 1,582 T USD
Advanced testing support Thermodynamics cEGR
Funded by DOE 180 T USDOwnFunding 0 T USD
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Milestones & Summary of Technical AccomplishmentsSensor Development
Baseline sensor characterization
Improve sensor mounting and ECU connector design; build prototypes
Sensor development for functional robustness over lifetime; build prototypes
Concept for 2nd generation IAO2 elementSystem Evaluation
Baseline system characterization (engine testing and simulation)
Assessment of system risks and requirements for sensor (intake conditions, controls)
Investigate impact of sensor location on sensor performance and requirements
Control Development
EGR estimation algorithm development
Control-oriented model for in-cylinder EGR prediction
Demonstration of sensing benefits
Engine simulation to demonstrate sensor benefits
• Demonstration of improved sensor functionality and robustness
• Demonstration of potential for fuel economy improvement and emissions performance
with IAO2 compared to a model-based EGR control strategy using rapid prototyping
black: completed 2013white: completed 2014
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
IAO2 Motivation
IAO2 ∆p
Accuracy over lifetime
HW Robustness
Dynamic
Cost
Risk
Calibration effort
• Elevated EGR rates requiredeven at part load to achieve highEGR rates at high load due to aircharge system dynamics
• Near unity pressure ratio with LP-EGR at low flows is challengingfor flow modeling and controlswith differential pressure sensor
Significant portion of drive cycle operating area with small pressure differential across EGR valve and cooler (< 5 mbar)
Sensing Alternatives for EGR Determination
IAO2 is a key enabler for maximizing the benefits of LP cooled EGR
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
50m
m
37.5
mm
50mm hole spacing30
mm
M18
2x 6
.75m
m
16.2mm Mounting Hole
LSU IM1 comparison to LSU 5.1 (diesel exhaust sensor)
LSU IM1 primary application is LP cEGR Gasoline and Diesel application
Project was launched with focus on Gasoline applications
Requirements for HP EGR applications are considered but not decision drivers
LSU IM1 concept:
• Use of single cell wideband element (LSU 5.1 element)
• High communality to existing production
• Change to direct connector
• Optimize PT for intake application
• Directional PT to achieve better trade-offs
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
PT Optimization Parameters
RobustnessThermal
Shock
RobustnessSoot and other con-taminants
HeaterPower Demand
Response Time
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
0 500 1000 1500 2000 2500 30001000
1500
2000
2500
3000
Time [s]
Eng
ine
Spe
ed [R
PM
]
0 500 1000 1500 2000 2500 3000
5
10
15
20
Time [s]
BM
EP
[bar
]
Formation Deposition
0 25 50 75 100 125 150 175 200 225 2500
0.20.40.60.8
11.21.41.61.8
2
Time into Endurance Run [hours]
No
rma
lize
d R
esp
on
se T
ime
[-]
Stable response time
IAO2 fouling robustness testSoot robustness test cycle
• Phase 1: Bosch reference “Aggressive” PN generation cycle
• Phase 2: Low flow velocity cycle to “bake on” particulate matter
• Automated in-situ response time test with intake N2 purge each cycle
• Continuous 24/7 automated running• 25 sensors tested with 14 different
protection tubes for 250 hours
Test Calibration Parameters• 10 to >25% eEGR commanded over
entire engine map• High particulates induced by modified
injection timing
Stable T63 response time observed over entire test independent of protection tube design
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Thermal Shock Testing
Results• Benchmarking of directional and non
directional designs
• Good thermal shock results are possible with non-directional and directional protection tubes
Test Method • New test method uses Bosch liquid sensor to
detect size and number of water droplets impacting sensor element
• Previous test method used sensor signal to evaluate the signal to noise ratio based on the cooling effect of water entering protection tube
High Thermal Shock Protection with a variety of directional and non directional designs
0
50
100
150
200
250
300
350
0.00
0.20
0.40
0.60
0.80
1.00
1.20
Non-direct1
Non-direct2
Non-direct3
Non-direct4
Directional1
Directional2
Directional3
Directional4
Wat
er D
ropl
et -
Num
ber
Wat
er D
ropl
et V
olum
e -A
vera
ge
Protection Tube
Thermal Shock Protection Tube Comparison
Avg Vol No. Drops
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Example of Protective Tube evaluation
Selection criteria• Switch time• Heater power demand• Water thermal shock resistance• Soot durability
Example shown is a projection tube of current production and proven in the field
0100200300400500
50 100 200 400 600 8000 100 200
Heater Power Demand Switch Time Soot Durability
-5.0
5.0
15.0
25.0
50 100 200 400 600 800
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Second Build and ValidationSecond Build completed in September 2014
Environmental Testing:• Thermal Cycling• Salt Water Submergence
Mechanical Testing:• Sine Vibration• Wideband Vibration
Purpose proof of robustness against environment:• Ensure sealing of components• Mechanical robustness of external and internal connections• Pre- and post- functionality of sensor
Results: No Design related failures
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
IAO2 AccuracyContributors of exhaust oxygen sensor LSU5.1 tolerance ± 3.5% @ λ=2.4:
Deviation from nominal value on air Humidity
Reduced tolerances for IAO2 sensor by improved pressure compensation: Online pressure measurement Pressure compensated air trimming Sensor specific k-value adaption Reduced pressure pulses
• Improved pressure compensation strategy established • Accuracy target of +/- 2% ΔO2/O2 can be reached• To check: Cross-sensitivities will have an impact on the accuracy depending on operating mode
total system error w/o electronics, w/o cross-sensitivity
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Accuracy
• Various exhaust species have a significant effect on the LSU IM’s signal, especially at rich conditions
• Previous testing by ORNL and modeling of the exhaust species at engine operating points shows the total error this generates
• Using this data and measurements from the LTG engine the errors were reduced from >23% at extreme operating conditions to ±2.5% at all conditions-25.0%
-22.5%
-20.0%
-17.5%
-15.0%
-12.5%
-10.0%
-7.5%
-5.0%
-2.5%
0.0%
2.5%
5.0%
0.6 0.7 0.8 0.9 1 1.1
Rela
tive
Erro
r in
Mol
ar O
2 Co
necn
trat
ion[
%]
Exhaust Lambda [-]
LSU IM Uncompensated LSU IM Compensated
Cross Sensitivities Resulting from Exhaust λ Deviations
-0.14% 0.28% 0.10%
-0.05%
-2.30%
0.08%
1.37%
λ=1, cEGR=20%, T=20°C, 100% Relative Humidity
CO H2O vap H2O EGR H2 Hydrocarbon NO O2(EGR)
-0.13%0.68%
0.42%-0.05%
-2.16%
0.08%
1.37%
λ=1, cEGR=20%, T=40°C, 100% Relative Humidity
CO H2O vap H2O EGR H2 Hydrocarbon NO O2(EGR)
-7.86%
0.11%0.21%
-2.70%
-2.63%
0.08%0.82%
λ=0.7, cEGR=20%, T=20°C, 100% Relative Humidity
CO H2O vap H2O EGR H2 Hydrocarbon NO O2(EGR)
TotalError:
-0.65%
TotalError:
-0.21%
TotalError:
-12.0%
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Real time testing at Clemson University has validated EGR correction and transport sub-systems
6
8
10
12
14
16
18
20
22
24
0
0.2
0.4
0.6
0.8
1
1.2
47 52 57La
mbd
a [-]
Time [Sec]
Lambda Exh TurbineLambda Exh IMOSEGR% Corrected with Exh LambdaEGR% Corrected with IMOS LambdaUncorrected EGR %
EGR
[%]
Exhaust Transport Time
Rich Correction
Transport Corrections
Phase 2 objectives for sensor correction and transport delay are complete
Intake O2 Sensor
Exhaust O2 Sensor
EGR transport and sensor correction control models are validated
EGR and Species Transport Models
EGR Valve
Controls
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Low pressure EGR control system
Transport models (completed)
EGR and Exhaust flow models (on-going)
EGR Valve Control (on-going)
IMOS signal correction (in final validation)
tdelay = 𝑳 𝑷 𝑨𝑹 𝑻 �̇�
�̇� 𝒕𝒉=𝑪𝑫 𝑨𝒕𝒉𝒑𝟎
𝑹 𝑻𝒐
𝒑𝑻𝒑𝟎
𝟏𝜸Ψ
𝒑𝑻𝒑𝟎
020
4060
80100
0.80.85
0.90.95
1
-50
0
50
100
150
200
Pressure ratioValve angle [deg]
Flow
rate
[kg/
hr]
Engine out emissionsprediction
IMOS sensitivity
ETAS Rapid Control Prototyping
BOSCH MED17 Engine ECU
Adaptive Control
Real-time Engine Testing
Control models will be delivered to BOSCH during Phase 3 for integration into ECUs
Phase 2 Phase 3
Control models will be delivered to Bosch during phase 3 for ECU integration
Controls
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Concept: Second Generation Sensor
• Potential to measure multiple species• Newly designed measurement concept• High water load robustness• Stable in lean conditions• Low pressure dependency• No humidity dependency• Lower heater power optimized for intake manifolds• Stabilized sensor temperature at high, cold flow rates• Flexibility regarding protection tube design • Two single cell sensors: 8 wire sensor concept• Free choice of sensor connector
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Future Directions REGISSensor Development
• Develop and demonstrate sensor functional robustness over lifetime• Investigate concept for 2nd generation IAO2 element
Demonstration of sensing benefits
• Demonstration of improved sensor functionality and robustness• Demonstration of potential for fuel economy improvement and emissions
performance achieved with IAO2 compared to a model-based EGR control strategy using rapid prototyping
19
DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Summary REGISRelevance of Intake Air Oxygen (IAO2) sensing • Directly and accurately measures the oxygen concentration in the intake manifold • Enables accurate and robust EGR control for future engine concepts utilizing cEGRApproach• Develop requirements • Design sensor solutions • Develop robust cEGR controlsTechnical Accomplishments Developed and demonstrated improved sensor mounting and ECU connector design Identified sensor design for improved thermal shock robustness and response time Assessed system risks and requirements for sensor (intake conditions, controls) Identified sensor location for best sensor performance and cEGR control Developed cEGR estimation algorithm Develop control-oriented model for in-cylinder EGR prediction Future Work• Develop and demonstrate sensor functional robustness over lifetime• Investigate concept for 2nd generation IAO2 element• Demonstrate sensing benefits
Tools• Targeted engines• Flow benches• Simulation studies
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Technical Back Up slides
21
DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Choice of Sensing Element• High water load robustness• Stable in lean conditions• Low pressure dependency• High soot robustness (optimized for Diesel engines)• Strong heater optimized for Diesel engines• Stabilized sensor temperature at high, cold flow rates• Flexibility regarding protection tube design • Single cell sensor : Compact 4 wire sensor concept
Free choice of sensor connector
Coating for thermal shock protection
Inner ElectrodeDiffusion Barrier
ZrO2
O--
Pumping Voltage
AirReferenceElectrode
ExhaustGas
22
DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
IAO2 Mounting Position
IAO2 mounting post-compressor is the best solution for durability, functionality and power consumption
Sensor Location
2000/2 3000/10
V8 5.0 NA
6000/9
2000/2
I4 2.0 GTDI
2000/15
Response Time [ms]
Overlapping regions where response time
and heater power requirements are met
5000/204000/16
2000/8
Gas Velocity
Res
pons
e Ti
me
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
IAO2 Mounting Position
Sensor Location
Gas Velocity
Res
pons
e Ti
me
IAO2 mounting post-compressor is the best solution for durability, functionality and power consumption
Significant margin to condensation
conditions only for Pre-CAC position
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DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Technical / technology
1 Sensor not robust for intake
2 Other methods for controlling EGR are better
3 Sensor can lead to ignition of intake gas
Development risk
4 Sensor accuracy not sufficient
5 Sensor costs higher than estimated
Competencies / Know-how
6 Unable to package sensor for intake
max
min
min max
prob
abili
ty
Potential risk
1
4
2
5
6
36
1
4
5 3
2
HC Cross Sensitivity in Gasoline Applications remain a challenge
Start of Project today
Technical Risk Assessment
25
DGS-ES | 04-10-2015 | © 2015 Robert Bosch LLC and affiliates. All rights reserved.
2015 DOE Annual Merit Review REGIS
Diesel Gasoline Systems
Assessment of Ignition RiskEliminate the very low ignition risk by one of
the following strategies:• Temp. control and heater diagnostic
Check sensor heater power demand withengine operating conditions
• Define purge conditionsAvoid explosive mixtures by avoidingpurging during tip-out (check valves intank purge lines after tip-out)
• An ignition is very unlikely and if with minor impact on the intake manifold (loss in boostdue to intake manifold damage)
• Elimination of the low ignition risk possible by simple application rules• No LSU IM1 design adjustments necessary to eliminate ignition risk
700
750
800
850
900
950
1000
1050
1100
Gasoline Methane Propane Isopentane N-Pentane
Min
imum
Obs
erve
d Ig
nitio
n Te
mpe
ratu
re (C
)
• Define mounting positionMounting of LSU-IM1 before throttlein case of T/C -systems
Minimum observed ignition temperature 929degC at worst case conditions: • Stoichiometric mixtures• Low flow conditions• Direct exposure to the hot ceramic element
Sensor operating temperature
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