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RF Antenna for SCR, TWC, GPF
Machine Learning for Load
Measurement
6th International Conference Aftertreatment & Sensors
Marco Moser, Munich, September 2019
Content
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
2
Update RF Antenna
Controls
OBD
Exhaust Gas After
Treatment Components
SCR Control with
Extended Kalman Filter
Motivation
Correct SCR Load Determination
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
3
High potential of RF antenna for SCR load determination
DOC SCR
DPF
SCR model
Engine
NOX
NH3
NH3load
Current Situation:
NH3load modelled
complex miscalculation
emissions
New RF (Microwave) Sensor:
NH3load measured
direct measurement
NH3load
Diesel
Amplitude damping
[dB]
-14
-13
-12
-11
-10
RF model 0g
RF model 2g
RF signal
SCR NH
3 load
[g]
0.5
1.0
1.5
2.0
Target load
ECU model load
NH3 mass error
[g]
0
1
2
Ti me [ s]
0
200
400
600
800
1000
ECU miscalculation
RF corrections acummulated
SCR Load Control -NH3Dosing Control
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
4
Implemented closed-loop control capable to compensate different errors without causing additional emission
Continuous error is corrected
visibly (saw teeth)
Time raster through filtering of
sensor signal
RF correction value corresponding
to ECU miscalculation
Example Road Measurement
Correction of calculated NH3load
Machine Learning Approach -RF Signal with ML
Compensation
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
5
Easy way for compensating cross influences in RF signal to get exact NH3load measurement
Stationary Tests -SCR Ageing: New, FUL, EOL
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
6
TSCR = 255°C
AdBlue®
dosing start dosing stop
empty
Amplitude damping shows effects of aged SCR: deterioration of storage capacity
difference from
stored humidity
difference from
stored humidity +
NH3
NEW
FUL
EOL
Transient Tests -SCR Ageing: FUL, EOL
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
7
With cross-influence-compensated RF signal it is possible to detect ageing of SCR
FUL ageing
EOL ageing
start with empty SCR
RF signal correlates
with:
-NH3load
-Humidity
-Temperature
-Ageing
Challenges in TWC Control
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
8
TWC performance depending on oxygen storage level
Upcoming challenges:
•Limited NH3emissions (NH3emitted under rich
conditions)
•Today’s applications: slightly rich operated engine,
TWC fully oxidized in fuel cuts
•Hybrid gasoline vehicles: no more fuel cut
New operation strategy requires new sensor?
RF advantages for TWC oxidation control
Sensor signal dependency on HC exhaust composition
RF Sensor advantage:
•Sensor is directly measuring the oxygen storage level
and not by indirect means
Optimal conversion
Lambda probe not
able to detect
oxidation state
RF able to detect
50% conversion
GPF Soot Loading Determination –RF Sensor Performance
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
9
Soot loading operation point
and temperature variation
Cold start sensor signal
0 0.5 1 1.5 2 2.5
time / s
10
4
0
1
2
3
4
m
soot
/ g
soot loading and temperature variation
soot load reference
soot load from RF
0 0.5 1 1.5 2 2.5
time / s
10
4
0
200
400
600
800
torque / Nm / T / °C
0.8
1
1.2
1.4
1.6
NOx-Sensor
torque / Nm T / °C lambda
0500 1000 1500
time / s
0
1
2
3
4
m
soot
/ g
cold start with 2,25 g soot load
soot load reference
soot load from RF
0 500 1000 1500
time / s
0
200
400
600
torque / Nm / T / °C
0.8
1
1.2
1.4
1.6
NOx-Sensor
torque / Nm
T / °C
lambda
0 200 400 600 800 1000 1200
time / s
0
1
2
3
4
m
soot
/ g
RDE with 3,35 g soot load
soot load reference
soot load from RF
0 200 400 600 800 1000 1200
time / s
0
100
200
300
400
torque / Nm / T / °C
0.8
1
1.2
1.4
1.6
NOx-Sensor
torque / Nm
T / °C
lambda
RDE test cycle with preloaded GPF
RF sensor advantage for GPF load determination:
•High soot load accuracy, temperature compensation as main influence, decreased accuracy at high transients
•Capability to measure in all states: cold start, engine off, operation
RF antenna as missing link to GPF control and OBD
Content
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
10
Update RF Antenna
Controls
OBD
Exhaust Gas After
Treatment Components
SCR Control with
Extended Kalman Filter
AECC Demonstrator Car (aecc.eu)
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
11
RF antennas integrated in demo car
AECC Demonstrator Car -Layout
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
12
Low & High Pressure EGR to reduce engine-out emissions
LNT + dual-SCR to cover wide range of driving conditions
•City driving: close-coupled LNT + SCR and SCR integrated on DPF (SDPF)
•Motorway driving: underfloor SCR and Ammonia Slip Catalyst (ASC)
Layout consisting of close-coupled and underfloor components cover a wide range of temperatures
AECC Demonstrator Car –Tailpipe Emissions
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
13
All measurements
far below emission
limits
Content
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
14
Update RF Antenna
Controls
OBD
Exhaust Gas After
Treatment Components
SCR Control with
Extended Kalman Filter
Extended Kalman Filter for SCR Dosing Control AECC Demo Car
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
15
If NH3slip is detected, the NH3load gets
corrected only in the right direction
necessary for a full loaded SCR
Over dosing and high NH3slip is avoided
, + 1.15 ,
SCRF SCR
,
LDM
SCRF
,
,,
,
,
ECU
signals
LDM
SCR
,
,,
,
NH3load
control
, + 1.15 ,
NOx
sensor us
NOx
sensor ds 2
AdBlue
injector 1
EKF 1
Dosing Control with NH3-slip Recognition
EKF 2
Model based dosing software
with NH3slip recognition
NOx
sensor ds 1
,,
,,
NH3slip
recognition
SCRF
/
NH3slip
recognition
SCR
/
Low dimensional
SCR models
EKFs for model
load correction
NH3slip recognition uses only NOX
sensor signals and is based on a
correlation approach
Low Dimensional Model -IAV-Software
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
16
Aim: Creation of a model capable of running on a standard ECU while modelling all relevant mechanisms of a SCR
Reaction Rates: Modelled Reaction Rates:
=, exp /( ) 1 NH3adsorption
=, exp ,(1 )/()NH3desorption
=, exp /(
), Standard SCR (reduction of NO)
=, exp /(
), Fast SCR (reduction of NO, NO2)
=, exp /(
), Slow SCR (reduction of NO2)
=, exp /(
),Oxidation of adsorbed NH3
Equations:
1)
,
=
2)
= 0
3)
= 0 =
, +
4)
= 0 = , 0.5
5)
=0=, 0.75 0.5
,
, =
with: =,
,,
,=
/(
),
=( , )
SCR modelling as a continuous, ideal tank (CSTR, 0D-modelling)
Arrhenius-approach for modelling reaction rates
Introduction of an additional state finj in order to compensate on drift effects
Extended Kalman Filter -Example: Correction of NH3Load in SCRF
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
17
Significant advantage of Kalman-filter: Adaption is functional with parametrization of the model.
H(1)*10^4
-1.0
-0.5
0.0
0.5
1.0
Geschw. [km/h]
0
100
200
Temp.
[°C]
0
100
200
300
H(1,1) defines the direction of the NH3load correction
Correction when NOx-slip occurs operating
in the opposite direction from NH3-slip.
NH3
NOx
0
NH3-slip
,
=, +,
=,
,
NOx-slip
unobservable
Observable through
RF antenna!
Correction because
of NH3slip
Correction because
of NOXslip
Without EKF
With EKF
With EKF and slip recognition
Results of Tolerance Analysis with IAV SCR Control
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
18
When NH3slip recognition activated, no more aberrations
Variance of the other results smaller compared to EKF only
Dosing Control with EKF
gets difficulties, if
tolerances accumulates to
NH3slip
SCR Control with Extended Kalman Filter -Prospects
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
19
Additional
Input
Advantages for combination of closed-loop control with RF antenna input
Antenna
Calibration
Model Based Dosing Control
Overview
IAV/Continental 09/2019 Moser -RF Antenna for SCR, TWC, GPF and Machine Learning for Load Measurement -6th International Conference Aftertreatment & Sensors
20
Experiences with model based approaches for different SCR dosing systems available (on PC and HD side)
Modular SCR dosing control concepts different layouts (single / tandem SCR, single or dual doser, w/ or w/o ASCR)
available
Closed loop dosing control or intelligent adaptation strategy recommended for robust DeNOx
(Model Based Dosing Control incl. EKF recommended for robust dosing control in future requirements)
2009 2013 2017 2018 2019
SCR Demonstrator
(ETB & 1st vehicle tests)
Customer A (EU)
SW development
Virtual Demonstrator
Different HD projects in HD-team
Selected References for Model Based SCR Dosing Control:
Customer B (EU)
Demonstrator
Customer C (EU)
Demonstrator
Customer D (EU)
Benchmark
MTZ
Journal
no. 02 / 2017
7th International
MinNOx
Conference
40.Internationales
Wiener Motoren-
symposium
Contact
Marco Moser
IAV GmbH
www.iav.com
Dr. Markus Dietrich
Continental Automotive GmbH
www.continental-corporation.com