New Methodology for Dynamic Drive Train Testing 2011-26-0045
In the process of power train development testing is essential. One option is to install on-board measuring equipment in a test vehicle and to execute test rides on a real road or proving ground. However, with regard to preparatory efforts as well as repeatability of test conditions, testing should be done on a test rig. This could be either a roller type dynamometer test bed, although dynamic testing is restricted due to the high moment of inertia of the rollers. Taking this and reduced cost into account a test setup with dynamometer directly attached to the wheel hubs of the test vehicle should be considered. This kind of test setup has already been used for some time. A major challenge in this setup is the appropriate control of the dynos in such a way that the desired test aims can be achieved.
The concept introduced here represents a new methodology for the control of power train test rigs with the main advantage that the power train experiences the same stress as on the real road - dependent on the individual pedal position of the driver and the selected condition of the road surface (dry, wet, icy, etc.). Even the intervention of Anti-lock Braking Systems (ABS) can be tested on the test rig without any additional precautions. Another advantage is the possibility of using the same dynos without any modification for the emulation of different moments of inertia of wheels resulting in an easy and fast test setup for different power trains. Furthermore, induction machines can be used as dynos with their well-known advantages (cost-efficient, very low torque ripple, fail-safe) compared to e.g. permanent magnet synchronous machines.