Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Model Based Testing of Automotive Control Function
Model Based Testing of
Automotive Control Functions
Matlab Expo, April 2015
Model-Based-Testing
System
Controls
Plant ModelAutomotive
Frontloading
Real Time
Closed-Loop
Code-genera
tion
Legacy
ECU
MBD
Calibration
Syste
m U
nder Test
Model Coverage
Validation
Verification
Test CaseCoding
Software
Hardware
QualityAccuracy
Functions
Feedback
Ankit Verma (RBEI/EEI5)
1
Simulation
Variants
Parameter
Consta
nt
Variables
Software-in-the-Loop
Model-in-th
e-LoopExperiments
Virtual
Concept
Simulation
Flashing
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Model Based Testing of Automotive Control Function
Agenda
1. Need for Model Based Testing
2. Conventional Vs MBD Approach
3. Test Environment Description
4. Testing of SUT using MBD Approach
5. System Simulation using Plant Model
6. Results
7. Benefits
8. Summary
2
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Model Based Testing of Automotive Control Function
1. Increasing Engine Control Complexity
Function Complexity increasingChallenges in maintaining quality
Increase in number of calibration More calibration effort
Increase number of ECU Increased inter domain connectivity
Need for Model Based Testing
Source: ETAS
New Functions &
VariantsIncreased inter domain connectivity
3
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Model Based Testing of Automotive Control Function
Conventional Vs MBD Approach
MBD Approach
System Analysis
Concept Eval
Concept Control Model
Plant Model
MiLOverall Control Model
Plant Model
SiLControl Model
Plant Model
RP/PiLControl Model
Plant Model
HiL
Plant Model
ViL
Vehicle
Conventional Approach
Function Model
Testing
Source Code Unit Testing Func validation
Compile/LinkCode generationFunction Design
Prototyping through H/W
Engine Test Bench
System Analysis
PC Environment Lab Environment
4
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Model Based Testing of Automotive Control Function
PLANT MODEL
Drive Train
*.dll from legacy
c-code
New Function
Model (ML/SL)
SUT (System
Under Test)
CONTROL MODEL
Software & Model in Loop
Test Output
Verification
Scheduler(DGS Lib)
Intake Vehicle
Closed Loop Test Environment Set-up
New
Control
Function -
SUT
(System
Under Test)
Engine
5
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
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Model Based Testing of Automotive Control Function
Testing of SUT (System Under Test)
using MBD Approach
6
Control Model
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
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Model Based Testing of Automotive Control Function
Closed loop Test Environment
MSE Plant Model
Control
Model Plant Model
Throttle
Angle [Deg]
Ignition
Angle [o CA]
Ignition
Timing [ms]
SoI [o CA]
Engine
Speed [rpm]
Manifold
Pressure [hPa] Gear [-]
Vehicle Speed [Kmph]
Lambda
Acc Pedal
Position
7
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Model Based Testing of Automotive Control Function
Test Case Description
Engine is in neutral gear
Check the engine behaviors with open drive train (neutral gear)
without consumer
S.No Test Case Description Observations
1. Unit Testing of Low Idle Speed Governor • Engine speed settles around the idle speed
• Low Idle governor working with speed deviation of
around -50 to 50 RPM
2. Engine in the Neutral Gear Engine Speed settles @ Idle Speed
3. Engine is in First Gear Engine speed increase during gear change from
neutral First
Engine speed settles to idle speed when gear
change from first zero.
8
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Model Based Testing of Automotive Control Function
Idle Speed Control – Test Results
Set Point Engine Speed [rpm]
Engine Speed [rpm]
Inference:
• Mass flow isn’t sufficient to achieve the desired idle
speed.
• Therefore, stepper configuration and by-pass valve
dimensions need to be calibrated
9
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
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Model Based Testing of Automotive Control Function
Next Step
1) Study of Engine behavior using simulation
Throttle & Ignition Sweep for different Engine Speed (800 – 2000
rpm)
Based on load variation to determine air mass flow through ISA
2) Component Dimensioning
Based on air mass flow – Area & Dia. of ISA to be fixed
10
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
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MSE work package: Model based Testing
Idle Speed Actuator - Component Sizing
0.25
1.25
2.25
3.25
4.25
5.25
6.25
7.25
8.25
0 5 10 15 20 25 30 35
To
rqu
e [
Nm
]
Throttle Angle [%]
Torque @ Varying throttle and Fixed Speed
800 RPM 1000 RPM
1200 RPM 1400 RPM
1600 RPM 1800 RPM
2000 RPM
0
0.25
0.5
0.75
1
1.25
1.5
1.75
2
2.25
2.5
2.75
3
3.25
3.5
3.75
4
4.25
4.5
4.75
5 10 15 20 25 30
Air
Ma
ss F
low
[K
g/h
r]
Throttle Angle [%]
Air Mass flow @ Varying Throttle and Fixed Speed
800 RPM 1000 RPM 1200 RPM
1400 RPM 1600 RPM 1800 RPM
2000 RPM
Considering 0.5-1 Nm
load variation from
electrical loads
(magneto) ideal low
idle speed could be
above 1400 rpm
Based on the load
variation of 0.5 –
1Nm, mass flow of
1.25 Kg/hr through
ISA is required
Torque Air Mass Flow Area of By Pass Valve
11
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
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Model Based Testing of Automotive Control Function
Component Dimensioning
d
By pass Valve
Old By-Pass
Valve
New By-Pass
Valve
Diameter 2.8 mm 3.98 mm
12
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Model Based Testing of Automotive Control Function
New By-pass Vs Old By-pass valve - Results
Set Point Engine Speed
[rpm]Engine Speed [rpm]
Eng
ine
Sp
ee
d [rp
m]
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0 20 40 60 80 100 120 140 160 180 200
Stepper Motor Steps [-]
Stepper Area [cm2]
Eng
ine
Sp
ee
d [rp
m]
Set Point Engine Speed
[rpm]Engine Speed [rpm]
0
0.002
0.004
0.006
0.008
0.01
0.012
0 20 40 60 80 100 120 140 160 180 200
Ste
pp
er
Are
a [
cm
2]
Stepper Motor Steps [-]
Stepper Area [cm2]
By P
ass A
rea
[cm
2]
By P
ass A
rea
[cm
2]
Old Stepper New Stepper
13
Confidential | RBEI/EEI5 | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also regarding any
disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Model Based Testing of Automotive Control Function
Pre-Calibration
14
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
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Model Based Testing of Automotive Control Function
Pre-calibration
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0.0035
-300 -200 -100 0 100 200 300
%T
orq
ue C
hange/r
pm
Engine Speed deviation [rpm]
P-gain (Air Path)
P-gain
0
0.05
0.1
0.15
0.2
0.25
-800 -600 -400 -200 0 200 400 600 800
%To
rqu
e C
ha
ng
e/r
pm
Engine Speed deviation [rpm]
P-gain (Air Path)
P-gain
Eng
ine
Sp
ee
d [rp
m] Set Point Engine Speed [rpm]
Engine Speed [rpm]
Eng
ine
Sp
ee
d [rp
m]
Deviation -100 to 100 rpm Deviation -50 to 50 rpm
15
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Model Based Testing of Automotive Control Function
Efficiency increase including development cost reduction
Early evaluation of control models and new control strategies frontloading
Reduce effort for validation of control models speed-up
Do more in virtual environment
Reduce dependence on dyno testing
System Level:
Concept evaluation before “make” decision
Investigate system behavior/function at early stage
Simulate extreme/rare environment conditions, safe experiments
Reusing plant models developed for other series project.
Benefit of Model Based Development
16
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
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Model Based Testing of Automotive Control Function
ECU-SW Level:
Easier debugging/reproducing of problems on PC
No reprogramming/flashing after every change in the functionality
Reuse ECU data
Benefit of Model Based Development
17
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Model Based Testing of Automotive Control Function
Desktop PC Simulation of implemented SW-functions together with the
available plant models allows a very early pre-calibration of these
functions and optimally supports the front-loading process in the area
of ECU-SW verification and validation.
The accuracy of the models is sufficient for concept evaluation w/o
measurement data and can be improved with measurement results to use
it for calibration tasks
Finally to deploy the virtual environment requires software as well as
system knowledge.
Summary
18
Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also
regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Model Based Testing of Automotive Control Function
19