Project Description

The model

Shifting process

It is state of the art in mechanical engineering and in vehicle design that products become developed in less time and with ever lower costs because of the use of hardware-in-the-loop test benchs (HiL). This change in the development process requires real-time models of complete systems. For simulations in real-time multibody models can be used. The challenge here lies in the determination of physical descriptions that quickly compute and that provide results of high quality. The most sophisticated task is the realistic depiction of non-linear and highly dynamic processes.
Such a highly dynamic process is the switching in a car. The gear change takes place within 0.2 to 0.8 seconds and includes the gear disengagement, the matching of the speed and the switching through. During this, numerous contact and friction processes between components out of complex geometries occure and a system change follows.
Currently in real time simulations mostly map required are used to represent the switching process. Basis of the parameter determination can be, for example, tests or calculations, that however do not meet the requirement of real-time capability.
The target of the research project is to develop a real-time capable and yet full physical synchronization model. For this purpose efficient multi-body model descriptions have been found, special algorithms for penetration search have been developed, fast models for the pre-synchronization have been programmed and for special circumstances, the procedure for numerical integration has been adjusted. So succeeds a real simulation of the switching process in a very short computing time.

Contact

• Dipl.-Ing. Markus Kirchner