Virtual Data Evaluation for ABS Maneuvers on Rough Roads

Transcription

1 Virtual Data Evaluation for ABS Maneuvers on Rough Roads Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads S. Brandes 1, Dr. Sedlaczek 1, U. Leidner 1, B. Seufert 1, R. Möller 2, Dr. Bruder 2 1 Daimler AG, Sindelfingen 2 Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF, Darmstadt 2. International Conference, Dynamic Simulation in Vehicle Engineering,

2 Contents 1. Multi Body Durability Simulations at Mercedes-Benz Cars 2. Objectives within the Development Process 3. Simulation Environment 4. Vehicle Model Quality for an ABS Maneuver 5. Evaluation of the Results for Closed Loop Computations 6. Summary 2 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF

3 1. Multi Body Durability Simulations at Mercedes-Benz Cars Digital Prototypes and Durability Assessment at Mercedes-Benz Cars DPT 1 DPT 2 DPT 3 Veh 1 DPT 4 Veh 2 Job #1 simulation of digital prototypes (DPT) hardware testing and prototypes Crash passenger protection NVH Durability BiW Ride/Handling Durability Suspension Integration Powertrain NVH Powertrain Energy Management Thermal Verfication Cooling Assembly At each milestone: analysis and evaluation of vehicle and component design and maturity Prerequisite for durability assessment: durability load data for each single component MBS simulation as service/data provider 3 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF

4 2. Objectives within the Development Process Durability-Specific Requirements and Challenges computation of all internal reaction forces plus additional properties (displacements, accelerations, etc.) F 2 (t) F 1 (t) output reference system 1500 output properties in 20 to 800 data files quasi static and short-term maneuvers and long-term on-road simulations highly nonlinear and progressive dynamics (bump/rebound stops, nonlinear bushing deformation, impact maneuvers, ) F 2 (t) challenging requirements for accuracy of results (10% off in amplitude 60% difference in lifetime) time series range pair (cycles) range pair (pseudo damage) force rainflow counting damage calculation time cumulative cycles cumulative damage 4 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF

5 P 3 1 _ F A S IK O _ V L _ Y (m m ) P 3 1 _ F A S IK O _ V L _ Z (m m ) P 3 1 _ F A S IK O _ V R _ X (m m ) P 3 1 _ F A S IK O _ V R _ Y (m m ) P 3 1 _ F A S IK O _ V R _ Z (m m ) P 3 1 _ K A R _ C G _ R E L _ X (m m ) P 3 1 _ K A R _ C G _ R E L _ Y (m m ) P 3 1 _ K A R _ C G _ R E L _ Z (m m ) P 3 1 _ K A R _ F A S I_ X (m m ) P 3 1 _ K A R _ F A S I_ Y (m m ) P 3 1 _ K A R _ F A S I_ Z (m m ) 8.2 P 3 1 _ K A R _ IXX (k g x m 2 ) P 3 1 _ K A R _ IXY (k g x m 2 ) 0 P 3 1 _ K A R _ IXZ (k g x m 2 ) 0 P 3 1 _ K A R _ IY Y (k g x m 2 ) P31_KAR _ IY Z (kgxm 2 ) 0 P 3 1 _ K A R _ IZZ (k g x m 2 ) P 3 1 _ K A R _ M A S S E (k g ) P 3 1 _ K A R _ U M G B _ B R _ E XC L U D E 0 P 3 1 _ K A R _ U M G B _ B R _ F L A G 0 P 3 1 _ R H O _ L U F T (k g _ m 3 ) P 1 _ B S C H _ B O D E N _ D IC K E (m m ) 6.5 P 1 _ B S C H _ C G _ R E L _ Z (m m ) P 1 _ B S C H _ D IC K E (m m ) P 1 _ B S C H _ IXX (k g x m 2 ) P 1 _ B S C H _ IZZ (k g x m 2 ) P 1 _ B S C H _ M A S S E (k g ) P 1 _ B S C H _ R A D IU S (m m ) P 1 _ B S C H _ TIE F E (m m ) 5 8 P 1 _ E T (m m ) 4 8 P 1 _ E T_ R E F (m m ) Simulation Environment Full Vehicle MBS Requires a Variety of Data and Different Components - about 2000 scalar parameters and 200 characteristic curves - sophisticated tire and bushing models, digitized road profiles, driver extremely complex environment Parameter File Bushing Model δ soll δ ist Characteristic Curves Driver Road Profile Tire Model 5 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF

6 3. Simulation Environment What about the Influence of Chassis Control Systems? longitudinal, lateral or vertical acting chassis control systems Electronic Stability Control (Antilock Braking System) Electronic Power Steering Suspension and Damping Control Electronic Power Steering Suspension and Damping Control Electronic Stability Control Antilock Braking System 6 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF

7 3. Simulation Environment Two Different Approaches of Linking Chassis Control Systems to MBS A. Original chassis control system including ECU code (Matlab/Simulink, Black Box) - requires IT-knowledge and support of supplier to link model with Virtual.Lab B. User-defined description of generic ABS functionality - open and simple source code is available and allows insight investigations A B FORTRAN routines SiL Controller Inside Matlab/Simulink model of the Software in the loop Controller Environment Generic description of an Antilock Braking System based on Fortran routines 7 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF

8 3. Simulation Environment Lessons Learned A. Original Code - Software Licences and Versions (Virtual.Lab Motion, DSHPlus, Matlab, Simulink, Compiler) - All files (e.g. static and dynamic libraries) must be available - Linking Black Boxes to VL.Motion can be difficult and error-prone (e.g. Real-Time Workshop) - Expert knowledge necessary B. Generic Code - Easy to integrate and use - Linking of the generic code just has to be done once 8 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF

9 4. Vehicle Model Quality for an ABS Maneuver Open Loop Vehicle Model Validation: Full Braking Maneuver Open Loop Simulation Velocity velocity time 1. Positioning of vehicle on road 2. Accelerating to the predefined velocity 3. Applying measured braking torques (no closed loop control) 4. Comparison with measurement results braking torque Measured braking torque measurement time 9 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF

10 4. Vehicle Model Quality for an ABS Maneuver Open Loop Vehicle Model Validation: Full Braking Maneuver E.g. tension strut forces (front axle) and compression strut forces (rear axle) overall comparison shows very good performance 10 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF

11 5. Evaluation of the Results for Closed Loop Computations closed-loop full braking on even road comparison of measured and simulated time series closed-loop full braking on rough road stochastic excitation comparison with measured results in time domain not appropriate power spectral density, rainflow counting and pseudo damage Animation: Braking on a rough road 11 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF

12 5. Evaluation of the Results for Closed Loop Computations Even Road Results different braking dynamics increasing braking torque characteristic peak not reproduced big influence of tire model friction characteristics 12 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF

13 5. Evaluation of the Results for Closed Loop Computations Rough Road Results difference in damage, maximum forces/torques and PSD single potholes or edges can have a dominant influence on damage analogue results for other properties further analyses are required 13 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF

14 6. Summary Contribution of Multi Body Durability Simulations to the Development Process Integration of ABS into MBS full vehicle simulation for durability load computation Investigations of two approaches: Original chassis control system User-defined description of generic ABS functionality Both approaches show comparable results Tire model fidelity has great influence (as expected) Further investigations are necessary 14 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF

15 Thank you for your attention! 15 Complete Vehicle Simulation for Virtual Data Evaluation in Highly Dynamical ABS Deceleration Processes on Rough Roads EP/ECF