The ITFC control with an MBS Truck Testrig SIMPACK User Meeting 2007

Transcription

1 The ITFC control with an MBS Truck Testrig SIMPACK User Meeting 2007 MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

2 Contents The ITFC control with an MBS Truck Testrig Introduction ITFC Virtual iteration Check of the iteration prozess Example: truck test rig for add-on parts Benefits of the virtual test rig Summary and outlook MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

3 Introduction Testing: customer conditions test course testrig virtual testrig MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

4 Initial situation Why a testrig controller? durability testrig vehicle measurements unknown: input system output known:! cylinder displacements! accelerations! forces! strains cylinder displacements acceleration, measurement cylinder position [m] acceleration [m/s^2] MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

5 ITFC Theory (I) Iterative Transfer Function Compensation Structure of the ITFC-method: 1) System identification 2) Iteration 1) System identification pink noise u(f) IFFT system H FFT system output y(f) output y(f) system H(f) = input u(f) MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

6 ITFC Theory (II) Iterative Transfer Function Compensation 2) Iteration (1 st Drive) 1 u1( f ) = H ( f ) y ( f Desired ) y Desired (t) measurement ( f ) y Desired (t) FFT y Desired u 1 ( f ) IFFT y 1 ( t) system u 1 ( t) u 1 ( t) data storage MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

7 ITFC Theory (III) Iterative Transfer Function Compensation 2) Iteration (2 nd Drive) 1 u1( f ) = H ( f ) y1( f ) measurement y Desired (t) y ( t 1 ) - FFT y 1 ( f ) u 1 ( f ) IFFT y 2 ( t) system u 2( t ) + u 1 ( t) u 1 ( t) data storage MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

8 Virtual iteration SIMPACK FEMFAT LAB measurement, accelerations virtual iteration (FEMFAT LAB) Iteration cylinder displacements (.if2) accelerations (.csv) MBS-model (SIMPACK) cylinder positions MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

9 Check of the iteration process SIMPACK FEMFAT LAB original excitation position acceleration acceleration position [m] acceleration [m/s^2] target position excitation postion [m] acceleration acceleration acceleartion [m/s^2] MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

10 Example Durability testrig for add-on parts MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

11 Results: Acceleration of the truck frame Acceleration of the truck frame (time domain) Measurement Simulation acceleration [m/s^2] Acceleration of the truck frame (levelcrossing) Measurement Simulation acceleration [m/s^2] number of cycles [-] MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

12 Results: Acceleration of the spare wheel Acceleration of the spare wheel (time domain) Measurement Simulation acceleration [m/s^2] Acceleration of the spare wheel (levelcrossing) Measurement Simulation acceleration [m/s^2] number of cycles [-] MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

13 Benefits of the virtual testrig Virtual part optimisation (quality, cost, time) in an early development phase. Minimisation of the test loops. Reduction of the tool changes. Generation of collective loads for the strength calculation. Optimisation of the testrig for a good correlation to the reality. MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

14 Summary and outlook Summary: Integration of ITFC-control into the SIMPACK-MBS testrig. Successful test of the iteration process. Application of the ITFC by a truck testrig for add-on parts. Outlook: " Construction of further testrigs. " Use of strains as target signals (virtual strain gauges). MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November

15 Thank you! The ITFC control with an MBS Truck Testrig MAN Nutzfahrzeuge AG Abteilung TESD B. Hertrampf / Dr. V. Mladek Dachauer Straße München MAN Nutzfahrzeuge AG B. Hertrampf / Dr. V. Mladek SIMPACK User Meeting November