Confidential | Ankit Verma (RBEI/EEI5) | 10/7/2014 | © Robert Bosch Engineering and Business Solutions Limited 2014. All rights reserved, also. regarding any ...
Model Based Testing of Automotive Control Function
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Validation
Calibration Hardware Quality Closed-Loop
Concept
Simulation
ECU
Plant Model
Feedback
Controls
Flashing
Test Case
Variants
Accuracy
Parameter
Simulation
Constant
Software
Model Coverage
Variables
Software-in-the-Loop
System
Functions
Model-in-the-Loop
Automotive
Frontloading
Experiments
Code-generation
Verification
Legacy
Virtual
MBD
Coding
Real Time
System Under Test
Model-Based-Testing
Model Based Testing of Automotive Control Functions
Matlab Expo, April 2015 Ankit Verma (RBEI/EEI5)
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
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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
Need for Model Based Testing 1.
Increasing Engine Control Complexity
Function Complexity increasing Challenges in maintaining quality
Increase in number of calibration More calibration effort
Increase number of ECU Increased inter domain connectivity
New Functions & Variants
Increased inter domain connectivity
Source: ETAS
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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 Conventional Approach System Analysis
Function Model
Source Code
Unit Testing
Func validation
Prototyping through H/W Code generation
Function Design
Compile/Link
Testing
Engine Test Bench
MBD Approach System Analysis
Concept Eval Concept Control Model
Plant Model
PC Environment MiL SiL Overall Control Model
Plant Model
Lab Environment RP/PiL HiL
Control Model
Control Model
Plant Model
Plant Model
ViL
Plant Model
Vehicle
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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
Closed Loop Test Environment Set-up Software & Model in Loop New Control Function SUT (System Under Test)
CONTROL MODEL
SUT (System Under Test)
*.dll from legacy c-code
New Function Model (ML/SL)
Scheduler (DGS Lib)
PLANT MODEL
Intake
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Engine
Drive Train
Test Output Verification Vehicle
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
Testing of SUT (System Under Test) using MBD Approach
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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
Closed loop Test Environment Control Model Acc Pedal Position
Lambda Engine Speed [rpm] Manifold Pressure [hPa]
Control Model
Throttle Angle [Deg]
MSE Plant Model
Ignition Angle [o CA] Ignition Timing [ms]
Plant Model
SoI [o CA] Gear [-] Vehicle Speed [Kmph]
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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
S.No 1.
Engine is in neutral gear Check the engine behaviors with open drive train (neutral gear) without consumer Test Case Description Unit Testing of Low Idle Speed Governor
Observations • Engine speed settles around the idle speed • Low Idle governor working with speed deviation of around -50 to 50 RPM
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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.
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
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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
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
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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.
MSE work package: Model based Testing
Idle Speed Actuator - Component Sizing Torque @ Varying throttle and Fixed Speed
8.25
Air Mass flow @ Varying Throttle and Fixed Speed 4.75
4.5 7.25
4.25
Considering 0.5-1 Nm load variation from electrical loads (magneto) ideal low idle speed could be above 1400 rpm
5.25
4.25
3.25
2.25 800 RPM 1200 RPM 1600 RPM 2000 RPM
1.25
1000 RPM 1400 RPM 1800 RPM
3.5 3.25 3
2.75 2.5 2.25
2 1.75 1.5
1.25 1 0.75
800 RPM
1000 RPM
1200 RPM
0.5
1400 RPM
1600 RPM
1800 RPM
0.25
0.25 0
5
10
15
Based on the load variation of 0.5 – 1Nm, mass flow of 1.25 Kg/hr through ISA is required
4 3.75
Air Mass Flow [Kg/hr]
Torque [Nm]
6.25
20
25
30
35
Throttle Angle [%]
2000 RPM
0 5
10
15
Throttle Angle [%]
Torque Air Mass Flow Area of By Pass Valve 11
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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.
25
30
Model Based Testing of Automotive Control Function
Component Dimensioning By pass Valve
Diameter
Old By-Pass Valve
New By-Pass Valve
2.8 mm
3.98 mm
d
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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 0.16
Stepper Area [cm2]
0.01 0.008 0.006 0.004 0.002
Old Stepper
0
0
20
40
60
By Pass Area [cm2]
[cm2] Pass Area ByStepper Area [cm2]
0.012
0.12 0.1 0.08 0.06
0.04 0.02 0
Engine Speed [rpm]
Engine Speed [rpm]
13
20
40
60
80
100 120 140 160 180 200
Stepper Motor Steps [-]
Stepper Motor Steps [-]
Engine Speed [rpm]
New Stepper
0
80 100 120 140 160 180 200
Set Point Engine Speed [rpm]
Stepper Area [cm2]
0.14
Engine Speed [rpm]
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.
Set Point Engine Speed [rpm]
Model Based Testing of Automotive Control Function
Pre-Calibration
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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 P-gain (Air Path)
P-gain (Air Path) 0.25
0.002 0.0015 P-gain
0.001
0.0005
Engine Speed [rpm]
-200
0 -100 0 100 Engine Speed deviation [rpm]
Deviation -100 to 100 rpm
200
300
0.2 0.15 0.1
P-gain
0.05 0 -800
-600
-400
-200
0
200
400
Engine Speed deviation [rpm]
Engine Speed [rpm]
%Torque Change/rpm
0.003 0.0025
-300
15
%Torque Change/rpm
0.0035
Set Point Engine Speed [rpm]
Deviation -50 to 50 rpm Engine Speed [rpm]
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.
600
800
Model Based Testing of Automotive Control Function
Benefit of Model Based Development
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
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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.
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
Benefit of Model Based Development
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ECU-SW Level:
Easier debugging/reproducing of problems on PC
No reprogramming/flashing after every change in the functionality
Reuse ECU data
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
Summary
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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.
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
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.
