LOAD SPECTRUM PREDICTION FOR TRANSMISSIONS UNDER REALISTIC USE COMBINING TESTS AND COMPUTER SIMULATIONS

摘要

In order to analyse road performance, fuel consumption and emission as well as fatigue life, it is important to know how the vehicle transmission performs under realistic conditions of use and over longer distances. The ever increasing complexity of transmissions demands extensive testing so that even rare or improbable occurrences can be taken into consideration. Driving tests with complete measuring equipment for recording the conditions of use are not possible in the construction phase (availability) and are only possible to a limited extent at a later stage because of the time and costs involved. Ascertaining load spectrums using computer simulation is therefore an important new development to supplement test drives and rig tests. Fuel consumption and emission is also becoming more and more important and this can be analysed with only minimal additional time and expense. The modular system described below is used for developing vehicle drive trains. The data shown here are the results for a DaimlerChrysler SLK 350 with 7-gear automatic transmission measured over a period of approximately 6 months. It was our aim to obtain load spectrums for the most varied driving conditions and to derive from these collectives which can be conveyed for practical use. To assess the influence of the vehicle engine, we also used two other vehicles, a small car (VW Lupo) and a middle class car (Audi A4 Quattro 2.5 TDI) taking measurements partly on the same routes.