Simulation-Aided Homologation of ESP Systems for NAFTA Vans by Software-In-The-Loop Simulation

Simulation-aided Homologation of ESP Systems for NAFTA Vans by Software-in-the-Loop Simulation

Klaus Wüst, Daimler AG Albert Lutz, Robert Bosch GmbH

IPG Technology Conference Ettlingen, 18.-19. September 2012

• ESP homologation by simulation – background of legislation • Simulation environment - SiL exchange platform OEM/supplier • Proof of functionality for vehicle variants on the basis of a validated “MasterCar” • Results of the survey, robustness • Banked curves robustness check • Conclusion

• In Europe: Mandatory introduction of ESP systems for passenger cars and for trucks or buses via ECE-R13 and ECE-R13H • ECE-R13 and –R13H allow homologation by simulation – either by HiL test stands or by SiL simulation • Type approval by simulation at Daimler Trucks since 2011 – Simulation tool EBSim (Simpack models with SiL codes) • Various driving maneuvers without precise criteria for trucks, maneuver “sine with dwell” for passenger cars, including pass/fail criteria • For NAFTA region: Mandatory introduction of ESP systems for passenger cars via FMVSS 126, maneuver “sine with dwell”, self-certification (no type approval by authorities)

System & Function Level Release

Calibration System Req. MiL SiL System Validation Rapid System & HiL Prototyping Function System Design Verification SiL SiL

SiL_generic SiL_generic Component Component Validation Requirements

Component OOL Component Design Verification

Implementation Component Level SW

Vehicle dynamics simulation tools ESP-Simulation tool  Vehicle, road, driver model  Control, sensor, brake model  OEM control systems  New braking system models  OEM test automation  Driver assistance

CSSim Vehicle, Driver, Environment, OEM- control inputs

Actuation & ESP signals Parameter modification CM-Signal trace ESP internal *.erg, *.info signal trace Animation *.d97 Daimler Combined trace file BOSCH

Public | K. Wüst u. A. Lutz | 19/09/2012 | © Daimler AG u Robert Bosch GmbH 2012. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights. 5 MasterCar - Approach Simulation-Workshop Application-Process DFP -Digital physical In-Vehicle FingerPrint Real Test Tests Drive Correlation

Measurement virtual Virtual Test = Master Car driven Drive Vehicle Variant A simulation

virtual RPM - Robustness & Performance Monitoring virtual Virtual Test Drive - with virtual Correlation parameter virtual variations Vehicle Variants B,C, Cars ..=Virtual

Public | K. Wüst u. A. Lutz | 19/09/2012 | © Daimler AG u Robert Bosch GmbH 2012. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights. 6 Validation of van vehicle dynamics using the “MasterCar” •Step 1: Proof of tire characteristics (MFTYRE) •Step 2: Measurement of 4 vehicle variants •Step 3: Yaw Velocity vs. Time Validation of steady state driving behavior

•Step 3: 40 Validation of transient driving behavior 30 20 •Step 4: 10 0 Validation of sine with dwell with ESC -10 14 16 18 20 22 24 interventions -20 G iergeschw indigkeit Comparison Measurement with ESC / Simulation -30 with ESC / Simulation without ESC, -40 -50 Vehicle yaw velocity as a response to 200° Zeit steering wheel amplitude

• Examples for the vehicle variety (Sprinter for NAFTA market):

• 2 GVW variants, 2 wheelbases, 2 heights, 2 versions of rear overhang, bus or goods transport, 4 suspension variants, 3 tire variants  approx. 120 possible variations • Additional: variation of loading conditions (laden/unladen, c.o.g position)

• All simulated vehicle variants have fulfilled the evaluation criteria • Step-by-step identification of worst case vehicle variants • Example result: Comparison between ESP8 and ESP9 code for one vehicle variant

Vergl ESP8 ESP9 Vergl ESp8 ESP9 Nafta KAWA 3.88t R2 LH2 CF2 C39 Nafta KAWA 3.88t R2 LH2 CF2 C39

4 100

3.5 80

60 3 40 2.5 20 ESP8 ESP8 2 ESP9 0 ESP9 -20 1.5 -40 1 -60

Seitenversatz nach 1.071s Lenkbeginn 0.5 -80 Norm. Giergeschw 1s nach Manöverende 1s nach Giergeschw Norm. -100 0 0 50 100 150 200 250 300 0 50 100 150 200 250 300 LW- Amplitude LW-Amplitude

Elevation Tracks: Final radius • Synthetic (S-Curve) • Test-center (PBx) • Public Road (cross-country Curvature up to Great Ocean Road) Initial Trajectory radius Elevation [rad] Elevation Track Y-Coordinate [m]

Track X-Coordinate [m] Track Length [m]

Measurement Simulation Track Analysis: Elevation ≥ x° Yaw Rate [rad/s] Yaw Rate

Banked Curve Detection: Time [s] Counter-Values

] Counter 1 2 Covering Counter 2

Curve Entering Yaw Rate Lat. Acceleration [m/s

Counter 1 Counter 2 Covering Criteria

Time [s]

• Daimler and Bosch have successfully estab- lished an exchange platform for the simulation of van vehicle dynamics with active systems. • The SiL platform is used for type approval investigations of ESP system as well as for investigations of a large amount of vehicle variants and for robustness investigations. • In future, this SiL process will also be used for other driver assistance systems, furthermore implementing additionally the tools IPG Test- Manager and QTronic TestWeaver.