AVL Software and Functions
NEW APPROACH FOR ENGINE
CONTROL SYSTEM SOFTWARE
DEVELOPMENT
6th CIMAC CASCADES 2015
Borja Pintos
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AGENDA
1. Engine control software development: Concept
2. Engine control software development over time
3. New approach: Model based development
a. Model based development: phases
b. Model based development: advantages
c. Model based development: example
4. Conclusions
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ENGINE CONTROL SOFTWARE DEVELOPMENT-CONCEPT
Software to control the complete powertrain system
Includes: sensors and actuators needed for control strategies
Typical control systems for large engines:
CLOSED LOOP CONTROL
Rotational engine speed control Rail pressure control Boost pressure control
Monitoring and diagnosis Emissions optimization Consumption optimization
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ENGINE CONTROL SOFTWARE DEVELOPMENT-CONCEPT
Typical example for a large engine: rotational engine speed control
A lever sets an engine speed set point
The Engine Control Unit (ECU) functionality shall keep the engine speed constant to the demand value
Engine
ECU Control Functionality
Engine speed
OutputVisualization
Speed Controller Fuel mass
Input
Engine speedset point
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ENGINE CONTROL SOFTWARE DEVELOPMENT OVER TIME
Mayor software improvements over time allowing for: shorter development time, reduce costs and increased quality
1 2
• Very time consuming• Poor overview• Need software experts
100%0% Time consuming
• Open loop test• Graphical model overview• Need software experts
100%0% Time consuming
~70%
+
Manual code generation
No test of requirements
Manual code generation
+Open loop test
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Auto code generation
+
ENGINE CONTROL SOFTWARE DEVELOPMENT OVER TIME
3 4
0% 100%Time consuming
~30%
• Open loop test• Graphical overview• Fast code generation. Code
generated without errors
100%0% Time consuming
~50%
• Closed loop test• Graphical overview• Fast code generation. Code
generated without errors
Auto code generation
+Open loop test
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Working flow:
1. Development of software functions using a graphical programming language (e.g. Simulink) according to the customer requirements
2. Test the software functions in Simulink using a virtual engine model (closed loop test)
3. Generate C code and flash it into the ECU
4. Verification of software functions at engine test bench (closed loop test)
OutputVisualization
Input
Stimuli
NEW APPROACH: MODEL BASED DEVELOPMENT
Engine
ECS Control Functionality
Speed Controller
Engine speedset point
Fuel mass
Engine speed
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NEW APPROACH: MODEL BASED DEVELOPMENT
Detailed engine model: Crank angle resolution for cylinder and gas path
Innovative, numerically-optimized approach and advanced solver technology allows real-time capability
Multiple applications of real-time engine models in the software development process
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MODEL BASED DEVELOPMENT: PHASES
Simulink
Model-in-the-Loop (MiL)
ECU concept
Functions and ECU development
Engine test bench
Verification
Refinement Simulink
ECU
HiL
Hardware-in-the-Loop (HiL)
ECU development
Pre-calibration, Monitoring, OBD
Hardware-TestsSimulink
ECU
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MODEL BASED DEVELOPMENT: PHASES
Simulink
Model-in-the-Loop (MiL)
ECU concept
Functions and ECU development
Entire Simulink environment
Development of functions
Virtual engine model interface
available for Simulink
Closed loop test using virtual
engine models
Motor model
State of the Art:
No model or very simple model (mean model, map)
AVL-Proposal:
Physical Model (Cylinder and air path in CRK angle
resolution)
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MODEL BASED DEVELOPMENT: PHASES
HiL
Hardware-in-the-Loop (HiL)
ECU development
Pre-calibration, Monitoring, OBD
Hardware-TestsSimulink
ECU
Real time PC ~ Virtual engine
ECU
Actuators
Wiring harness
Computer for data analysis
Lever
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MODEL BASED DEVELOPMENT: ADVANTAGES
• Higher maturity of engine
control achieved earlier in
the development
• No risk of engine-
component damage in MiL
& HiL environment
• Pre-calibration and
validation of control
functionality are developed
in MiL & HiL environment
• Model based software
development saves time
and money and improves
quality of the software
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MODEL BASED DEVELOPMENT: EXAMPLE
Motor type (~ 1 MW per Cyl.)
Bore > 300 mm
Dual Fuel (Diesel, Gas)
One stage turbo with
wastegate
Motor bypass and compressor
bypass valve developed for fine
-control
Variable valve timing
Generator operation, ship
propulsion
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MODEL BASED DEVELOPMENT: EXAMPLE
Air path (incl. Wastegate,
Compressor-Bypass and Motor-Bypass)
Charging & Intercooling
Fuel supply(Gas & Diesel)
Cylinder & Motor (Wall heattransfer, combustion
characteristics, valve lift, flowcharacteristics, moment of
inertia…)Variable valve
timing
Brake, external load
Building the model Software development Closed loop test (HiL)
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MODEL BASED DEVELOPMENT: EXAMPLE
Plant ModelECS Control Functionality
Speed Controller
BoostPressureController
PBoost
Demand
EngineEngine speed
Lambda
Boost pressure
Fuel mass
Waste gate
Bypass valve
Engine speedset point
Boost pressureset point
Lambdaset point
Operating point
Building the model Software development Closed loop test (HiL)
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MODEL BASED DEVELOPMENT: EXAMPLE
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
Zeit [s]
Moto
rdre
hzahl [
Upm
]
450
500
550
600
650
700
750
Ein
spritz
menge [g/H
ub]
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Last ist konstant (100%).
Engin
e s
peed [
rpm
] Load is constant (100%)
Fuel quantity
[g/s
tk]
Building the model Software development Closed loop test (HiL)
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MODEL BASED DEVELOPMENT: EXAMPLE
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
Zeit [s]
Moto
rdre
hzahl [
Upm
]
450
500
550
600
650
700
750
Lam
bda [-]
1.0
1.5
2.0
2.5
3.0
3.5
Ladedru
ck [bar]
2.5
3.0
3.5
4.0
4.5
5.0
5.5
Wate
gate
-Ste
llung [%
]
0
20
40
60
80
100
-Sollwert
-Istwert
Ladedruck-SollwertLadedruck-Istwert
Last ist konstant (100%).Load is constant (100%)
Building the model Software development Closed loop test (HiL)
Lam
bda [
-]W
gpositio
n [
%]
Boost
pre
ssure
[bar]
Setpoint
Actual
Boost pressure
actual value
Boost pressure
setpoint
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CONCLUSIONS
Model based software development saves time and money and
improves software quality
Innovative, physical real-time engine models (simulation in crank
angle resolution, 0D gas dynamics) allow the observation of various
motor phenomena that can not be considered with mean value models
www.avl.com
THANK YOU
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