MDYNAMIX AFFILIATED INSTITUTE OF MUNICH UNIVERSITY OF APPLIED SCIENCES MXSTEERINGDESIGNER AUTOMATED STEERING MODEL PARAMETER IDENTIFICATION AND OPTIMIZATION 1
THE OBJECTIVE Valid steering models Measurement from steering testbench Accurate physical parameters to fit any model to reality 2
OVERVIEW Which tests do I need to do? Which parameters are relevant for a certain behaviour? How to automate the process? Which development environment? Questions, answered by the MXsteeringdesigner How to estimate parameters that cannot be measured? 3
OVERVIEW Environment Steering System EPS Power Assist HPS Power Assist Steering Model User Defined Model Test Catalogue User Interface Automated process for a optimum usability and quick results Iterative Optimization Characteristic tests to identify the overall charcteristic behaviour Driving Maneuver tests to analyse the dynamic response of a steering system 4
OVERVIEW Environment Steering System EPS Power Assist HPS Power Assist Steering Model User Defined Model Test Catalogue User Interface Automated process for a optimum usability and quick results Iterative Optimization Characteristic tests to identify the overall charcteristic behaviour Driving Maneuver tests to analyse the dynamic response of a steering system 5
SUPPORTED STEERING SYSTEMS Electrical Power Steering (EPS) Hydraulic Power Steering (HPS) EPS Column EPS Pinion EPS Rack 6
OVERVIEW Environment Steering System EPS Power Assist HPS Power Assist Steering Model User Defined Model Test Catalogue User Interface Automated process for a optimum usability and quick results Iterative Optimization Characteristic tests to identify the overall charcteristic behaviour Driving Maneuver tests to analyse the dynamic response of a steering system 7
PFEFFER MXSTEERING EPS and HPS systems 3 DOF model Realtime capable Physical model parameters High + Low-frequency behaviour User defined ECU models Suitable for NVH, Steering feel and -handling 8
CUSTOM MODEL SIMULINK based steering model Compiled excutable model using SIMULINK Coder Model implementation directly in MXsteeringdesigner Parameter identification and optimization for user defined steering models 9
OVERVIEW Environment Steering System EPS Power Assist HPS Power Assist Steering Model User Defined Model Test Catalogue User Interface Automated process for a optimum usability and quick results Iterative Optimization Characteristic tests to identify the overall charcteristic behaviour Driving Maneuver tests to analyse the dynamic response of a steering system 10
TEST CATALOGUE System Characteristic Tests Driving Maneuver Tests Static tests regarding the overall characteristics System Stiffness: Overall stiffness of the complete assembled steering system Steering Ratio: SW rotation Rack movement Column Friction: Friction of upper column Rack Friction: Friction of the steering rack Boost Curve: Measurement of assist power at certain vehicle speeds Open loop tests regarding the steering behaviour Transition Test: according to ISO 13674-2, for boost curve and static friction validation Weave Test: according to ISO 13674-1, for a validation of the dynamic friction behaviour Dynamic Test: e.g. sinus sweep, step input, to check the dynamic response of the system, i.e. damping, inertia, ECU delays, 11
OVERVIEW Environment Steering System EPS Power Assist HPS Power Assist Steering Model User Defined Model Test Catalogue User Interface Automated process for a optimum usability and quick results Iterative Optimization Characteristic tests to identify the overall charcteristic behaviour Driving Maneuver tests to analyse the dynamic response of a steering system 12
ITERATIVE OPTIMIZATION Features 5-10min per maneuver and velocity Iterative optimization loop Multi objective optimization Steering Wheel Torque, Steering Rack Displacement and multiple Velocities at once Optimize parameters which we cannot measure (inertia, damping, friction stiffness, ) 13
OVERVIEW Environment Steering System EPS Power Assist HPS Power Assist Steering Model User Defined Model Test Catalogue User Interface Automated process for a optimum usability and quick results Iterative Optimization Characteristic tests to identify the overall charcteristic behaviour Driving Maneuver tests to analyse the dynamic response of a steering system 14
WORKFLOW Parameter Import Load parameter file or import default parameters System Characteristic tests System Stiffness Column Friction Rack Friction Steering Ratio Boost Curve Driving maneuver tests Transition test Weave test Dynamic test Final parameter set Analyse the different optimization steps Export plots and parameters 15
USER INTERFACE 16
OVERVIEW Environment Steering System EPS Power Assist HPS Power Assist Steering Model User Defined Model Test Catalogue User Interface Automated process for a optimum usability and quick results Iterative Optimization Characteristic tests to identify the overall charcteristic behaviour Driving Maneuver tests to analyse the dynamic response of a steering system 17
ENVIRONMENT Windows standalone Executable (64bit) Developed in MATLAB and SIMULINK environment MATLAB Compiler FlexNet Licensing (nodelocked or network license) combined with MATLAB compiler runtime Standalone application that includes all MATLAB benefits! 18
MDYNAMIX AFFILIATED INSTITUTE OF MUNICH UNIVERSITY OF APPLIED SCIENCES Contact Information MdynamiX AG Address: Hessstraße 89, 80797 München Tel.: +49 89 12765047 Fax.: +49 89 95444585 Mail: info@mdynamix.de Web: www.mdynamix.de 19