Verification of Multibody Models of the TriHyBus on the Basis of Experimental Measurements
The TriHyBus (abbreviation of the Triple Hybrid Hydrogen Bus) project comprises research and development, implementation and a test operation of a 12-meter city bus with a hybrid electric propulsion using hydrogen fuel cells.The vehicle driveability is comparable with the characteristics of standard buses.However, the mass distribution and the total bus mass are rather different.It is the reason of verifying the bus chassis strength (connected with vertical dynamics) and investigating the bus stability (I.e.horizontal dynamics).In order to obtain a tool for dynamic analysis several types of multibody models of hydrogen bus were created using the alaska simulation tool and using the MATLAB system.Each model has its advantages and its drawbacks and can be used for different purposes.The rigid bodies correspond to the bus individual structural parts.Air springs and hydraulic shock absorbers in axles suspension and bushings in the places of mounting certain bus structural parts are modeled by connecting the corresponding bodies by nonlinear spring-damper elements.The stationary tire model is used to describe directional properties of the tires.Unfamiliarity of the TriHyBus real shock absorbers force-velocity characteristics was a crucial problem in the investigation of its vertical dynamic properties using computer simulations.Operational tests performed in March 2012 were focused on vertical dynamics of the empty bus.The operational tests on an uneven test track (so called bump tests) were carried out in a modified way according to the ODA RESEARCH road vehicles testing methodology.A standard artificial test track is created on a common bitumen road with a set of four portable standard bumps (obstacles), the shape of which is defined in the CSN 30 0560 Czech Standard.On the basis of comparing the simulations results (time histories of the air springs relative deflections) and the relative displacement between the axles and the chassis frame that were measured at the testing drives with the real TriHyBus, force-velocity characteristics of shock absorbers in axles’ suspension have been improved in the multibody models.There are three criteria for determining the improved characteristics.The principal one is achieving as similar character as possible of time histories of air springs relative deflections determined at simulations and corresponding time histories of relative displacement between the axles and the chassis frame determined at the experimental measurement.The second one is keeping the similar character of characteristics course as the “usual force-velocity characteristics of shock absorbers.The third criterion is achieving as high coincidence as possible of the extreme values of the time histories of air springs relative deflections determined at simulations with the corresponding extreme values determined at the experimental measurement.s.
Pavel Polach Jaroslav Václavík Michal Haj(z)man
Materials and Mechanical Engineering ResearchResearch and Testing Institute Plzen Ltd.Plzen,30100,Cz Dynamic Testing LaboratoryResearch and Testing Institute Plzen Ltd.Plzen,30100,Czech Republic Computer-Aided Modelling Research and Testing Institute Plzen Ltd.Plzen,30100,Czech Republic
国际会议
上海
英文
1-8
2012-08-26（万方平台首次上网日期，不代表论文的发表时间）