b'Engineer Innovation | AutomotiveBy pre- degrees of freedom (DOFs) so that theefficiencies and energy losses of the calculation can run in real-time, but onmain components necessary to predict the other hand the simulation modelfuel economy. The model was definingneeds to remain sufficiently accurate sosystematically built from component to that it still produces realistic results.full vehicle, validated in each of these majorThis requires very specialized softwarestages, and later simplified to run in tools. By using Simcenter Amesimreal time.software from Siemens PLM Software calibrationfor the plant model in co-simulationReducing physical testingwith the MATLAB, Simulink andThe project we did with the Simcenter Stateflow environments for theEngineering specialists showed us that values usingcontroller models, we could achievewe can realize a good correlation this objective really well. between results from HiL simulation HiLBesides the supervisory hybrid controland the real vehicle behavior for multiple attributes simultaneously, unit (HCU), which was the main subjectsays Jae-Sung. It confirmed that we simulation,of the validation study, the engineerscan use this approach for upfront also had to model the subsystemperformance validation, as it allows us we were ablecontrollers to an appropriate level ofto quickly evaluate trends when detail. The engine management systemdesigning HCU algorithms and defining (EMS) for example, regulates fuel, aircalibration values, so that we can to reduce theand spark to produce the torque that isachieve a better starting point for commanded from the HCU. If thisphysical prototyping.number offeature is not modeled accurately, it canThe implementation of the Simcenter lead to significant deviations when predicting fuel economy and theAmesim based process as a standard actual vehiclebatterys state of charge. Otherdevelopment practice allows Hyundai subsystems add to the complexity. engineers to improve the performance tests by 40The dynamic Simcenter Amesim modelof HEVs while dramatically reducing time and cost. By pre-defining major included the required physics tocalibration values using HiL simulation, percent. accurately capture the energy flows andwe were able to reduce the number of conversions from fuel to mechanicalactual vehicle tests by 40 percent, Bang Jae-Sung, Ph.D.and electrical energy. For drivabilityconfirms Jae-Sung. And we are in the Senior engineer R&D Centerassessment, the model possessed allprocess of extending the scope of this Hyundai Motor Company the relevant elements for replicatingmethodology to a much larger number the natural frequencies between 0 andof test scenarios, by including 20 Hertz (Hz), as these can be felt byadditional physics in the models, such the driver. The model also included theas thermal effects on engine, electric 52'