X-in-the-loop enables earlier testing, faster development

March 24, 2016 // By Christoph Hammerschmidt
In order to achieve better utilisation of cost-intensive development tools and test stands for electric vehicles, five research institutes in Germany have launched a laboratory network that enables real-time testing of vehicles and components even if these components are spatially distributed. The move represents an enhancement of the standard HiL (Hardware-in-the-loop) test approach towards what the researchers call XiL (X-in-the-loop).

The complex interplay of mechanical, electric and IT components in modern vehicles requires systematic, highly integrated development processes and development environments. It is essential to be able to test individual components thoroughly in an early stage of the development, even before the entire system exists. Towards this end, researchers have developed what they call X-in-the-loop which allows developers to test whatever they have while the components the device under test interacts with are simulated on computers. The laboratory network launched by the five institutes in Germany goes one step further in that it removes the requirement of spatial proximity – the models to interact with can run on remote computers. This facilitates and accelerates the development process and enables better utilisation of complex, expensive development tools like those used in electric vehicle advanced development. For example, the researchers can put a transmission through its paces whereas components that do not even exist yet can like the behaviour of the motor(s), the vehicle longitudinal dynamics or the tire behaviour can be mapped through dynamic actuators with specific models and simulations. 


The five institutes involved in the XiL-BW-e project are the KIT in Karlsruhe, the universities of Stuttgart and Ulm (the latter one with specific resources for battery research) as well as the universities of applied sciences in Aalen and Esslingen. The project is funded in part by state ministry of education, research and technology of Baden-Württemberg. As soon as the state of the project permits, the network will be made available to commercial users.


A similar project is currently under way in Austria: The Virtual Vehicle research centre in Graz is in the middle of carrying out the ACOSAR project. The goal of this project is creating a standardised interface to connect test stands together, be the devices under test real or virtual. The rationale in both projects is enabling engineers to test early in the development process, true