Abstract
Due to the increasing complexity of modern vehicle concepts new methods to integrate simulation and test on each level of the validation chain are required. Especially for the development of advanced driver assistant systems with focus on safety and energy efficiency the interaction between the unit under test, the driver and the environment like traffic, road topology, etc. are very important and must be considered in detail.
In different domains there are existing established methods. Influences of human-machineinterfaces are analysed e.g. using very detailed driving simulators. The behaviour of control units can be tested in interaction with the vehicle without real vehicle components on a hardware-in-the-loop (HiL) simulator. Calibration of powertrain components like transmissions can be done automatically on a roller test bench.
Bringing together the advantages of domain-specific development and validation environments, the IPEK – Institute of Product Engineering has implemented a Vehicle-in-theloop platform based on its X-in-the-loop approach. The open architecture to integrate different simulation models and real components, the usage of established tools and methods and the integration in a development process to realize new possibilities for frontloading are the main aspects of the system of objectives for such a platform.
In comparison with other concepts, this platform is based on a common hardware-in-the-loopsystem with extended I/O-communication to the vehicle and optional to the test bench. The application is done in C and Matlab/Simulink. So an exchange of simulation models, test cases, etc. is possible; e.g. the same test cases using on a HiL-simulator for control unit testing can be used on the vehicle-in-the-loop platform. Furthermore different integration levels of the driver and the environment are possible. E.g. a real driver in the real vehicle, a real driver in a driving simulator (connected to the real vehicle on the test bench) or a virtual driver model can be applied. Application area of the Vehicle-in-the-loop-platform can be the roller test bench or a proving ground.
This allows doing highly reproducible and automated tests with the whole vehicle in the loop considering the influences of different driver types and different environmental situations. The advantages of the Vehicle-in-the-loop-platform are demonstrated in this paper with a concrete application example.
Keywords: X-in-the-loop, Vehicle-in-the-loop, Advanced Driver Assistant Systems, Development Methods, Validation Methods